3760 lines
99 KiB
C
3760 lines
99 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/spinlock.h>
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#include <linux/list.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/gpio.h>
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#include <linux/of_gpio.h>
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#include <linux/idr.h>
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <linux/gpio/driver.h>
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#include <linux/gpio/machine.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/cdev.h>
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#include <linux/fs.h>
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#include <linux/uaccess.h>
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#include <linux/compat.h>
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#include <linux/anon_inodes.h>
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#include <linux/file.h>
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#include <linux/kfifo.h>
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#include <linux/poll.h>
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#include <linux/timekeeping.h>
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#include <uapi/linux/gpio.h>
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#include "gpiolib.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/gpio.h>
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/* Implementation infrastructure for GPIO interfaces.
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*
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* The GPIO programming interface allows for inlining speed-critical
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* get/set operations for common cases, so that access to SOC-integrated
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* GPIOs can sometimes cost only an instruction or two per bit.
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*/
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/* When debugging, extend minimal trust to callers and platform code.
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* Also emit diagnostic messages that may help initial bringup, when
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* board setup or driver bugs are most common.
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*
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* Otherwise, minimize overhead in what may be bitbanging codepaths.
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*/
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#ifdef DEBUG
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#define extra_checks 1
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#else
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#define extra_checks 0
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#endif
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/* Device and char device-related information */
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static DEFINE_IDA(gpio_ida);
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static dev_t gpio_devt;
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#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
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static struct bus_type gpio_bus_type = {
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.name = "gpio",
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};
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/* gpio_lock prevents conflicts during gpio_desc[] table updates.
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* While any GPIO is requested, its gpio_chip is not removable;
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* each GPIO's "requested" flag serves as a lock and refcount.
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*/
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DEFINE_SPINLOCK(gpio_lock);
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static DEFINE_MUTEX(gpio_lookup_lock);
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static LIST_HEAD(gpio_lookup_list);
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LIST_HEAD(gpio_devices);
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static void gpiochip_free_hogs(struct gpio_chip *chip);
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static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
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static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
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static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
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static bool gpiolib_initialized;
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static inline void desc_set_label(struct gpio_desc *d, const char *label)
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{
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d->label = label;
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}
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/**
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* Convert a GPIO number to its descriptor
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*/
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struct gpio_desc *gpio_to_desc(unsigned gpio)
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{
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struct gpio_device *gdev;
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unsigned long flags;
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spin_lock_irqsave(&gpio_lock, flags);
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list_for_each_entry(gdev, &gpio_devices, list) {
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if (gdev->base <= gpio &&
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gdev->base + gdev->ngpio > gpio) {
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spin_unlock_irqrestore(&gpio_lock, flags);
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return &gdev->descs[gpio - gdev->base];
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}
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}
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spin_unlock_irqrestore(&gpio_lock, flags);
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if (!gpio_is_valid(gpio))
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WARN(1, "invalid GPIO %d\n", gpio);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(gpio_to_desc);
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/**
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* Get the GPIO descriptor corresponding to the given hw number for this chip.
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*/
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struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
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u16 hwnum)
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{
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struct gpio_device *gdev = chip->gpiodev;
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if (hwnum >= gdev->ngpio)
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return ERR_PTR(-EINVAL);
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return &gdev->descs[hwnum];
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}
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/**
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* Convert a GPIO descriptor to the integer namespace.
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* This should disappear in the future but is needed since we still
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* use GPIO numbers for error messages and sysfs nodes
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*/
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int desc_to_gpio(const struct gpio_desc *desc)
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{
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return desc->gdev->base + (desc - &desc->gdev->descs[0]);
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}
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EXPORT_SYMBOL_GPL(desc_to_gpio);
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/**
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* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
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* @desc: descriptor to return the chip of
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*/
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struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
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{
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if (!desc || !desc->gdev || !desc->gdev->chip)
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return NULL;
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return desc->gdev->chip;
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}
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EXPORT_SYMBOL_GPL(gpiod_to_chip);
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/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
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static int gpiochip_find_base(int ngpio)
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{
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struct gpio_device *gdev;
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int base = ARCH_NR_GPIOS - ngpio;
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list_for_each_entry_reverse(gdev, &gpio_devices, list) {
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/* found a free space? */
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if (gdev->base + gdev->ngpio <= base)
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break;
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else
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/* nope, check the space right before the chip */
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base = gdev->base - ngpio;
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}
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if (gpio_is_valid(base)) {
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pr_debug("%s: found new base at %d\n", __func__, base);
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return base;
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} else {
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pr_err("%s: cannot find free range\n", __func__);
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return -ENOSPC;
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}
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}
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/**
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* gpiod_get_direction - return the current direction of a GPIO
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* @desc: GPIO to get the direction of
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*
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* Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
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*
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* This function may sleep if gpiod_cansleep() is true.
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*/
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int gpiod_get_direction(struct gpio_desc *desc)
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{
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struct gpio_chip *chip;
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unsigned offset;
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int status = -EINVAL;
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chip = gpiod_to_chip(desc);
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offset = gpio_chip_hwgpio(desc);
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/*
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* Open drain emulation using input mode may incorrectly report
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* input here, fix that up.
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*/
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if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
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test_bit(FLAG_IS_OUT, &desc->flags))
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return 0;
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if (!chip->get_direction)
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return status;
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status = chip->get_direction(chip, offset);
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if (status > 0) {
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/* GPIOF_DIR_IN, or other positive */
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status = 1;
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clear_bit(FLAG_IS_OUT, &desc->flags);
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}
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if (status == 0) {
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/* GPIOF_DIR_OUT */
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set_bit(FLAG_IS_OUT, &desc->flags);
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}
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return status;
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}
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EXPORT_SYMBOL_GPL(gpiod_get_direction);
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/*
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* Add a new chip to the global chips list, keeping the list of chips sorted
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* by range(means [base, base + ngpio - 1]) order.
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*
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* Return -EBUSY if the new chip overlaps with some other chip's integer
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* space.
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*/
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static int gpiodev_add_to_list(struct gpio_device *gdev)
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{
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struct gpio_device *prev, *next;
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if (list_empty(&gpio_devices)) {
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/* initial entry in list */
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list_add_tail(&gdev->list, &gpio_devices);
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return 0;
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}
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next = list_entry(gpio_devices.next, struct gpio_device, list);
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if (gdev->base + gdev->ngpio <= next->base) {
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/* add before first entry */
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list_add(&gdev->list, &gpio_devices);
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return 0;
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}
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prev = list_entry(gpio_devices.prev, struct gpio_device, list);
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if (prev->base + prev->ngpio <= gdev->base) {
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/* add behind last entry */
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list_add_tail(&gdev->list, &gpio_devices);
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return 0;
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}
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list_for_each_entry_safe(prev, next, &gpio_devices, list) {
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/* at the end of the list */
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if (&next->list == &gpio_devices)
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break;
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/* add between prev and next */
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if (prev->base + prev->ngpio <= gdev->base
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&& gdev->base + gdev->ngpio <= next->base) {
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list_add(&gdev->list, &prev->list);
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return 0;
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}
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}
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dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
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return -EBUSY;
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}
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/**
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* Convert a GPIO name to its descriptor
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*/
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static struct gpio_desc *gpio_name_to_desc(const char * const name)
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{
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struct gpio_device *gdev;
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unsigned long flags;
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spin_lock_irqsave(&gpio_lock, flags);
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list_for_each_entry(gdev, &gpio_devices, list) {
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int i;
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for (i = 0; i != gdev->ngpio; ++i) {
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struct gpio_desc *desc = &gdev->descs[i];
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if (!desc->name || !name)
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continue;
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if (!strcmp(desc->name, name)) {
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spin_unlock_irqrestore(&gpio_lock, flags);
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return desc;
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}
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}
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}
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spin_unlock_irqrestore(&gpio_lock, flags);
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return NULL;
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}
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/*
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* Takes the names from gc->names and checks if they are all unique. If they
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* are, they are assigned to their gpio descriptors.
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*
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* Warning if one of the names is already used for a different GPIO.
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*/
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static int gpiochip_set_desc_names(struct gpio_chip *gc)
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{
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struct gpio_device *gdev = gc->gpiodev;
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int i;
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if (!gc->names)
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return 0;
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/* First check all names if they are unique */
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for (i = 0; i != gc->ngpio; ++i) {
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struct gpio_desc *gpio;
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gpio = gpio_name_to_desc(gc->names[i]);
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if (gpio)
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dev_warn(&gdev->dev,
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"Detected name collision for GPIO name '%s'\n",
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gc->names[i]);
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}
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/* Then add all names to the GPIO descriptors */
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for (i = 0; i != gc->ngpio; ++i)
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gdev->descs[i].name = gc->names[i];
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return 0;
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}
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/*
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* GPIO line handle management
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*/
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/**
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* struct linehandle_state - contains the state of a userspace handle
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* @gdev: the GPIO device the handle pertains to
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* @label: consumer label used to tag descriptors
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* @descs: the GPIO descriptors held by this handle
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* @numdescs: the number of descriptors held in the descs array
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*/
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struct linehandle_state {
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struct gpio_device *gdev;
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const char *label;
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struct gpio_desc *descs[GPIOHANDLES_MAX];
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u32 numdescs;
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};
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#define GPIOHANDLE_REQUEST_VALID_FLAGS \
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(GPIOHANDLE_REQUEST_INPUT | \
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GPIOHANDLE_REQUEST_OUTPUT | \
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GPIOHANDLE_REQUEST_ACTIVE_LOW | \
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GPIOHANDLE_REQUEST_OPEN_DRAIN | \
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GPIOHANDLE_REQUEST_OPEN_SOURCE)
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static long linehandle_ioctl(struct file *filep, unsigned int cmd,
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unsigned long arg)
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{
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struct linehandle_state *lh = filep->private_data;
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void __user *ip = (void __user *)arg;
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struct gpiohandle_data ghd;
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int i;
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if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
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int val;
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memset(&ghd, 0, sizeof(ghd));
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/* TODO: check if descriptors are really input */
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for (i = 0; i < lh->numdescs; i++) {
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val = gpiod_get_value_cansleep(lh->descs[i]);
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if (val < 0)
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return val;
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ghd.values[i] = val;
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}
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if (copy_to_user(ip, &ghd, sizeof(ghd)))
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return -EFAULT;
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return 0;
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} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
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int vals[GPIOHANDLES_MAX];
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/* TODO: check if descriptors are really output */
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if (copy_from_user(&ghd, ip, sizeof(ghd)))
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return -EFAULT;
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/* Clamp all values to [0,1] */
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for (i = 0; i < lh->numdescs; i++)
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vals[i] = !!ghd.values[i];
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/* Reuse the array setting function */
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gpiod_set_array_value_complex(false,
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true,
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lh->numdescs,
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lh->descs,
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vals);
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return 0;
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}
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return -EINVAL;
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}
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#ifdef CONFIG_COMPAT
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static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
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unsigned long arg)
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{
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return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
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}
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#endif
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static int linehandle_release(struct inode *inode, struct file *filep)
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{
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struct linehandle_state *lh = filep->private_data;
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struct gpio_device *gdev = lh->gdev;
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int i;
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for (i = 0; i < lh->numdescs; i++)
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gpiod_free(lh->descs[i]);
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kfree(lh->label);
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kfree(lh);
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put_device(&gdev->dev);
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return 0;
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}
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static const struct file_operations linehandle_fileops = {
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.release = linehandle_release,
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.owner = THIS_MODULE,
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.llseek = noop_llseek,
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.unlocked_ioctl = linehandle_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = linehandle_ioctl_compat,
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#endif
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};
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static int linehandle_create(struct gpio_device *gdev, void __user *ip)
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{
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struct gpiohandle_request handlereq;
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struct linehandle_state *lh;
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struct file *file;
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int fd, i, count = 0, ret;
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u32 lflags;
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if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
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return -EFAULT;
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if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
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return -EINVAL;
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lflags = handlereq.flags;
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/*
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* Do not allow both INPUT & OUTPUT flags to be set as they are
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* contradictory.
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*/
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if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
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(lflags & GPIOHANDLE_REQUEST_OUTPUT))
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return -EINVAL;
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lh = kzalloc(sizeof(*lh), GFP_KERNEL);
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if (!lh)
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return -ENOMEM;
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lh->gdev = gdev;
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get_device(&gdev->dev);
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/* Make sure this is terminated */
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handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
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if (strlen(handlereq.consumer_label)) {
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lh->label = kstrdup(handlereq.consumer_label,
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GFP_KERNEL);
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if (!lh->label) {
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ret = -ENOMEM;
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goto out_free_lh;
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}
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}
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|
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/* Request each GPIO */
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for (i = 0; i < handlereq.lines; i++) {
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u32 offset = handlereq.lineoffsets[i];
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struct gpio_desc *desc;
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if (offset >= gdev->ngpio) {
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ret = -EINVAL;
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goto out_free_descs;
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}
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|
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/* Return an error if a unknown flag is set */
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if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) {
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ret = -EINVAL;
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goto out_free_descs;
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}
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desc = &gdev->descs[offset];
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ret = gpiod_request(desc, lh->label);
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if (ret)
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goto out_free_descs;
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lh->descs[i] = desc;
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count = i + 1;
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if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
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set_bit(FLAG_ACTIVE_LOW, &desc->flags);
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if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
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set_bit(FLAG_OPEN_DRAIN, &desc->flags);
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if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
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set_bit(FLAG_OPEN_SOURCE, &desc->flags);
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/*
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* Lines have to be requested explicitly for input
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* or output, else the line will be treated "as is".
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*/
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if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
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int val = !!handlereq.default_values[i];
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ret = gpiod_direction_output(desc, val);
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if (ret)
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goto out_free_descs;
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} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
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ret = gpiod_direction_input(desc);
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if (ret)
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goto out_free_descs;
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}
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dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
|
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offset);
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}
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/* Let i point at the last handle */
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i--;
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lh->numdescs = handlereq.lines;
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fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
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if (fd < 0) {
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ret = fd;
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goto out_free_descs;
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}
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|
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file = anon_inode_getfile("gpio-linehandle",
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&linehandle_fileops,
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lh,
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O_RDONLY | O_CLOEXEC);
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if (IS_ERR(file)) {
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ret = PTR_ERR(file);
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goto out_put_unused_fd;
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|
}
|
|
|
|
handlereq.fd = fd;
|
|
if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
|
|
/*
|
|
* fput() will trigger the release() callback, so do not go onto
|
|
* the regular error cleanup path here.
|
|
*/
|
|
fput(file);
|
|
put_unused_fd(fd);
|
|
return -EFAULT;
|
|
}
|
|
|
|
fd_install(fd, file);
|
|
|
|
dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
|
|
lh->numdescs);
|
|
|
|
return 0;
|
|
|
|
out_put_unused_fd:
|
|
put_unused_fd(fd);
|
|
out_free_descs:
|
|
for (i = 0; i < count; i++)
|
|
gpiod_free(lh->descs[i]);
|
|
kfree(lh->label);
|
|
out_free_lh:
|
|
kfree(lh);
|
|
put_device(&gdev->dev);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* GPIO line event management
|
|
*/
|
|
|
|
/**
|
|
* struct lineevent_state - contains the state of a userspace event
|
|
* @gdev: the GPIO device the event pertains to
|
|
* @label: consumer label used to tag descriptors
|
|
* @desc: the GPIO descriptor held by this event
|
|
* @eflags: the event flags this line was requested with
|
|
* @irq: the interrupt that trigger in response to events on this GPIO
|
|
* @wait: wait queue that handles blocking reads of events
|
|
* @events: KFIFO for the GPIO events
|
|
* @read_lock: mutex lock to protect reads from colliding with adding
|
|
* new events to the FIFO
|
|
*/
|
|
struct lineevent_state {
|
|
struct gpio_device *gdev;
|
|
const char *label;
|
|
struct gpio_desc *desc;
|
|
u32 eflags;
|
|
int irq;
|
|
wait_queue_head_t wait;
|
|
DECLARE_KFIFO(events, struct gpioevent_data, 16);
|
|
struct mutex read_lock;
|
|
};
|
|
|
|
#define GPIOEVENT_REQUEST_VALID_FLAGS \
|
|
(GPIOEVENT_REQUEST_RISING_EDGE | \
|
|
GPIOEVENT_REQUEST_FALLING_EDGE)
|
|
|
|
static unsigned int lineevent_poll(struct file *filep,
|
|
struct poll_table_struct *wait)
|
|
{
|
|
struct lineevent_state *le = filep->private_data;
|
|
unsigned int events = 0;
|
|
|
|
poll_wait(filep, &le->wait, wait);
|
|
|
|
if (!kfifo_is_empty(&le->events))
|
|
events = POLLIN | POLLRDNORM;
|
|
|
|
return events;
|
|
}
|
|
|
|
|
|
static ssize_t lineevent_read(struct file *filep,
|
|
char __user *buf,
|
|
size_t count,
|
|
loff_t *f_ps)
|
|
{
|
|
struct lineevent_state *le = filep->private_data;
|
|
unsigned int copied;
|
|
int ret;
|
|
|
|
if (count < sizeof(struct gpioevent_data))
|
|
return -EINVAL;
|
|
|
|
do {
|
|
if (kfifo_is_empty(&le->events)) {
|
|
if (filep->f_flags & O_NONBLOCK)
|
|
return -EAGAIN;
|
|
|
|
ret = wait_event_interruptible(le->wait,
|
|
!kfifo_is_empty(&le->events));
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (mutex_lock_interruptible(&le->read_lock))
|
|
return -ERESTARTSYS;
|
|
ret = kfifo_to_user(&le->events, buf, count, &copied);
|
|
mutex_unlock(&le->read_lock);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* If we couldn't read anything from the fifo (a different
|
|
* thread might have been faster) we either return -EAGAIN if
|
|
* the file descriptor is non-blocking, otherwise we go back to
|
|
* sleep and wait for more data to arrive.
|
|
*/
|
|
if (copied == 0 && (filep->f_flags & O_NONBLOCK))
|
|
return -EAGAIN;
|
|
|
|
} while (copied == 0);
|
|
|
|
return copied;
|
|
}
|
|
|
|
static int lineevent_release(struct inode *inode, struct file *filep)
|
|
{
|
|
struct lineevent_state *le = filep->private_data;
|
|
struct gpio_device *gdev = le->gdev;
|
|
|
|
free_irq(le->irq, le);
|
|
gpiod_free(le->desc);
|
|
kfree(le->label);
|
|
kfree(le);
|
|
put_device(&gdev->dev);
|
|
return 0;
|
|
}
|
|
|
|
static long lineevent_ioctl(struct file *filep, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
struct lineevent_state *le = filep->private_data;
|
|
void __user *ip = (void __user *)arg;
|
|
struct gpiohandle_data ghd;
|
|
|
|
/*
|
|
* We can get the value for an event line but not set it,
|
|
* because it is input by definition.
|
|
*/
|
|
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
|
|
int val;
|
|
|
|
memset(&ghd, 0, sizeof(ghd));
|
|
|
|
val = gpiod_get_value_cansleep(le->desc);
|
|
if (val < 0)
|
|
return val;
|
|
ghd.values[0] = val;
|
|
|
|
if (copy_to_user(ip, &ghd, sizeof(ghd)))
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
static const struct file_operations lineevent_fileops = {
|
|
.release = lineevent_release,
|
|
.read = lineevent_read,
|
|
.poll = lineevent_poll,
|
|
.owner = THIS_MODULE,
|
|
.llseek = noop_llseek,
|
|
.unlocked_ioctl = lineevent_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = lineevent_ioctl_compat,
|
|
#endif
|
|
};
|
|
|
|
static irqreturn_t lineevent_irq_thread(int irq, void *p)
|
|
{
|
|
struct lineevent_state *le = p;
|
|
struct gpioevent_data ge;
|
|
int ret, level;
|
|
|
|
/* Do not leak kernel stack to userspace */
|
|
memset(&ge, 0, sizeof(ge));
|
|
|
|
ge.timestamp = ktime_get_real_ns();
|
|
level = gpiod_get_value_cansleep(le->desc);
|
|
|
|
if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
|
|
&& le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
|
|
if (level)
|
|
/* Emit low-to-high event */
|
|
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
|
|
else
|
|
/* Emit high-to-low event */
|
|
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
|
|
} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
|
|
/* Emit low-to-high event */
|
|
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
|
|
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
|
|
/* Emit high-to-low event */
|
|
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
|
|
} else {
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
ret = kfifo_put(&le->events, ge);
|
|
if (ret != 0)
|
|
wake_up_poll(&le->wait, POLLIN);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int lineevent_create(struct gpio_device *gdev, void __user *ip)
|
|
{
|
|
struct gpioevent_request eventreq;
|
|
struct lineevent_state *le;
|
|
struct gpio_desc *desc;
|
|
struct file *file;
|
|
u32 offset;
|
|
u32 lflags;
|
|
u32 eflags;
|
|
int fd;
|
|
int ret;
|
|
int irqflags = 0;
|
|
|
|
if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
|
|
return -EFAULT;
|
|
|
|
le = kzalloc(sizeof(*le), GFP_KERNEL);
|
|
if (!le)
|
|
return -ENOMEM;
|
|
le->gdev = gdev;
|
|
get_device(&gdev->dev);
|
|
|
|
/* Make sure this is terminated */
|
|
eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
|
|
if (strlen(eventreq.consumer_label)) {
|
|
le->label = kstrdup(eventreq.consumer_label,
|
|
GFP_KERNEL);
|
|
if (!le->label) {
|
|
ret = -ENOMEM;
|
|
goto out_free_le;
|
|
}
|
|
}
|
|
|
|
offset = eventreq.lineoffset;
|
|
lflags = eventreq.handleflags;
|
|
eflags = eventreq.eventflags;
|
|
|
|
if (offset >= gdev->ngpio) {
|
|
ret = -EINVAL;
|
|
goto out_free_label;
|
|
}
|
|
|
|
/* Return an error if a unknown flag is set */
|
|
if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
|
|
(eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
|
|
ret = -EINVAL;
|
|
goto out_free_label;
|
|
}
|
|
|
|
/* This is just wrong: we don't look for events on output lines */
|
|
if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
|
|
(lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
|
|
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
|
|
ret = -EINVAL;
|
|
goto out_free_label;
|
|
}
|
|
|
|
desc = &gdev->descs[offset];
|
|
ret = gpiod_request(desc, le->label);
|
|
if (ret)
|
|
goto out_free_label;
|
|
le->desc = desc;
|
|
le->eflags = eflags;
|
|
|
|
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
|
|
ret = gpiod_direction_input(desc);
|
|
if (ret)
|
|
goto out_free_desc;
|
|
|
|
le->irq = gpiod_to_irq(desc);
|
|
if (le->irq <= 0) {
|
|
ret = -ENODEV;
|
|
goto out_free_desc;
|
|
}
|
|
|
|
if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
|
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
|
|
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
|
|
if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
|
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
|
|
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
|
|
irqflags |= IRQF_ONESHOT;
|
|
irqflags |= IRQF_SHARED;
|
|
|
|
INIT_KFIFO(le->events);
|
|
init_waitqueue_head(&le->wait);
|
|
mutex_init(&le->read_lock);
|
|
|
|
/* Request a thread to read the events */
|
|
ret = request_threaded_irq(le->irq,
|
|
NULL,
|
|
lineevent_irq_thread,
|
|
irqflags,
|
|
le->label,
|
|
le);
|
|
if (ret)
|
|
goto out_free_desc;
|
|
|
|
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
ret = fd;
|
|
goto out_free_irq;
|
|
}
|
|
|
|
file = anon_inode_getfile("gpio-event",
|
|
&lineevent_fileops,
|
|
le,
|
|
O_RDONLY | O_CLOEXEC);
|
|
if (IS_ERR(file)) {
|
|
ret = PTR_ERR(file);
|
|
goto out_put_unused_fd;
|
|
}
|
|
|
|
eventreq.fd = fd;
|
|
if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
|
|
/*
|
|
* fput() will trigger the release() callback, so do not go onto
|
|
* the regular error cleanup path here.
|
|
*/
|
|
fput(file);
|
|
put_unused_fd(fd);
|
|
return -EFAULT;
|
|
}
|
|
|
|
fd_install(fd, file);
|
|
|
|
return 0;
|
|
|
|
out_put_unused_fd:
|
|
put_unused_fd(fd);
|
|
out_free_irq:
|
|
free_irq(le->irq, le);
|
|
out_free_desc:
|
|
gpiod_free(le->desc);
|
|
out_free_label:
|
|
kfree(le->label);
|
|
out_free_le:
|
|
kfree(le);
|
|
put_device(&gdev->dev);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* gpio_ioctl() - ioctl handler for the GPIO chardev
|
|
*/
|
|
static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct gpio_device *gdev = filp->private_data;
|
|
struct gpio_chip *chip = gdev->chip;
|
|
void __user *ip = (void __user *)arg;
|
|
|
|
/* We fail any subsequent ioctl():s when the chip is gone */
|
|
if (!chip)
|
|
return -ENODEV;
|
|
|
|
/* Fill in the struct and pass to userspace */
|
|
if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
|
|
struct gpiochip_info chipinfo;
|
|
|
|
memset(&chipinfo, 0, sizeof(chipinfo));
|
|
|
|
strncpy(chipinfo.name, dev_name(&gdev->dev),
|
|
sizeof(chipinfo.name));
|
|
chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
|
|
strncpy(chipinfo.label, gdev->label,
|
|
sizeof(chipinfo.label));
|
|
chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
|
|
chipinfo.lines = gdev->ngpio;
|
|
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
|
|
return -EFAULT;
|
|
return 0;
|
|
} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
|
|
struct gpioline_info lineinfo;
|
|
struct gpio_desc *desc;
|
|
|
|
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
|
|
return -EFAULT;
|
|
if (lineinfo.line_offset >= gdev->ngpio)
|
|
return -EINVAL;
|
|
|
|
desc = &gdev->descs[lineinfo.line_offset];
|
|
if (desc->name) {
|
|
strncpy(lineinfo.name, desc->name,
|
|
sizeof(lineinfo.name));
|
|
lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
|
|
} else {
|
|
lineinfo.name[0] = '\0';
|
|
}
|
|
if (desc->label) {
|
|
strncpy(lineinfo.consumer, desc->label,
|
|
sizeof(lineinfo.consumer));
|
|
lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
|
|
} else {
|
|
lineinfo.consumer[0] = '\0';
|
|
}
|
|
|
|
/*
|
|
* Userspace only need to know that the kernel is using
|
|
* this GPIO so it can't use it.
|
|
*/
|
|
lineinfo.flags = 0;
|
|
if (test_bit(FLAG_REQUESTED, &desc->flags) ||
|
|
test_bit(FLAG_IS_HOGGED, &desc->flags) ||
|
|
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
|
|
test_bit(FLAG_EXPORT, &desc->flags) ||
|
|
test_bit(FLAG_SYSFS, &desc->flags))
|
|
lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
|
|
if (test_bit(FLAG_IS_OUT, &desc->flags))
|
|
lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
|
|
lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
|
|
GPIOLINE_FLAG_IS_OUT);
|
|
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
|
|
lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
|
|
GPIOLINE_FLAG_IS_OUT);
|
|
|
|
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
|
|
return -EFAULT;
|
|
return 0;
|
|
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
|
|
return linehandle_create(gdev, ip);
|
|
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
|
|
return lineevent_create(gdev, ip);
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* gpio_chrdev_open() - open the chardev for ioctl operations
|
|
* @inode: inode for this chardev
|
|
* @filp: file struct for storing private data
|
|
* Returns 0 on success
|
|
*/
|
|
static int gpio_chrdev_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct gpio_device *gdev = container_of(inode->i_cdev,
|
|
struct gpio_device, chrdev);
|
|
|
|
/* Fail on open if the backing gpiochip is gone */
|
|
if (!gdev || !gdev->chip)
|
|
return -ENODEV;
|
|
get_device(&gdev->dev);
|
|
filp->private_data = gdev;
|
|
|
|
return nonseekable_open(inode, filp);
|
|
}
|
|
|
|
/**
|
|
* gpio_chrdev_release() - close chardev after ioctl operations
|
|
* @inode: inode for this chardev
|
|
* @filp: file struct for storing private data
|
|
* Returns 0 on success
|
|
*/
|
|
static int gpio_chrdev_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct gpio_device *gdev = container_of(inode->i_cdev,
|
|
struct gpio_device, chrdev);
|
|
|
|
put_device(&gdev->dev);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static const struct file_operations gpio_fileops = {
|
|
.release = gpio_chrdev_release,
|
|
.open = gpio_chrdev_open,
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.unlocked_ioctl = gpio_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = gpio_ioctl_compat,
|
|
#endif
|
|
};
|
|
|
|
static void gpiodevice_release(struct device *dev)
|
|
{
|
|
struct gpio_device *gdev = dev_get_drvdata(dev);
|
|
|
|
list_del(&gdev->list);
|
|
ida_simple_remove(&gpio_ida, gdev->id);
|
|
kfree(gdev->label);
|
|
kfree(gdev->descs);
|
|
kfree(gdev);
|
|
}
|
|
|
|
static int gpiochip_setup_dev(struct gpio_device *gdev)
|
|
{
|
|
int status;
|
|
|
|
cdev_init(&gdev->chrdev, &gpio_fileops);
|
|
gdev->chrdev.owner = THIS_MODULE;
|
|
gdev->chrdev.kobj.parent = &gdev->dev.kobj;
|
|
gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
|
|
status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
|
|
if (status < 0)
|
|
chip_warn(gdev->chip, "failed to add char device %d:%d\n",
|
|
MAJOR(gpio_devt), gdev->id);
|
|
else
|
|
chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
|
|
MAJOR(gpio_devt), gdev->id);
|
|
status = device_add(&gdev->dev);
|
|
if (status)
|
|
goto err_remove_chardev;
|
|
|
|
status = gpiochip_sysfs_register(gdev);
|
|
if (status)
|
|
goto err_remove_device;
|
|
|
|
/* From this point, the .release() function cleans up gpio_device */
|
|
gdev->dev.release = gpiodevice_release;
|
|
pr_info("%s: registered GPIOs %d to %d on device: %s (%s)\n",
|
|
__func__, gdev->base, gdev->base + gdev->ngpio - 1,
|
|
dev_name(&gdev->dev), gdev->chip->label ? : "generic");
|
|
|
|
return 0;
|
|
|
|
err_remove_device:
|
|
device_del(&gdev->dev);
|
|
err_remove_chardev:
|
|
cdev_del(&gdev->chrdev);
|
|
return status;
|
|
}
|
|
|
|
static void gpiochip_setup_devs(void)
|
|
{
|
|
struct gpio_device *gdev;
|
|
int err;
|
|
|
|
list_for_each_entry(gdev, &gpio_devices, list) {
|
|
err = gpiochip_setup_dev(gdev);
|
|
if (err)
|
|
pr_err("%s: Failed to initialize gpio device (%d)\n",
|
|
dev_name(&gdev->dev), err);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gpiochip_add_data() - register a gpio_chip
|
|
* @chip: the chip to register, with chip->base initialized
|
|
* Context: potentially before irqs will work
|
|
*
|
|
* Returns a negative errno if the chip can't be registered, such as
|
|
* because the chip->base is invalid or already associated with a
|
|
* different chip. Otherwise it returns zero as a success code.
|
|
*
|
|
* When gpiochip_add_data() is called very early during boot, so that GPIOs
|
|
* can be freely used, the chip->parent device must be registered before
|
|
* the gpio framework's arch_initcall(). Otherwise sysfs initialization
|
|
* for GPIOs will fail rudely.
|
|
*
|
|
* gpiochip_add_data() must only be called after gpiolib initialization,
|
|
* ie after core_initcall().
|
|
*
|
|
* If chip->base is negative, this requests dynamic assignment of
|
|
* a range of valid GPIOs.
|
|
*/
|
|
int gpiochip_add_data(struct gpio_chip *chip, void *data)
|
|
{
|
|
unsigned long flags;
|
|
int status = 0;
|
|
unsigned i;
|
|
int base = chip->base;
|
|
struct gpio_device *gdev;
|
|
|
|
/*
|
|
* First: allocate and populate the internal stat container, and
|
|
* set up the struct device.
|
|
*/
|
|
gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
|
|
if (!gdev)
|
|
return -ENOMEM;
|
|
gdev->dev.bus = &gpio_bus_type;
|
|
gdev->chip = chip;
|
|
chip->gpiodev = gdev;
|
|
if (chip->parent) {
|
|
gdev->dev.parent = chip->parent;
|
|
gdev->dev.of_node = chip->parent->of_node;
|
|
}
|
|
|
|
#ifdef CONFIG_OF_GPIO
|
|
/* If the gpiochip has an assigned OF node this takes precedence */
|
|
if (chip->of_node)
|
|
gdev->dev.of_node = chip->of_node;
|
|
#endif
|
|
|
|
gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
|
|
if (gdev->id < 0) {
|
|
status = gdev->id;
|
|
goto err_free_gdev;
|
|
}
|
|
dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
|
|
device_initialize(&gdev->dev);
|
|
dev_set_drvdata(&gdev->dev, gdev);
|
|
if (chip->parent && chip->parent->driver)
|
|
gdev->owner = chip->parent->driver->owner;
|
|
else if (chip->owner)
|
|
/* TODO: remove chip->owner */
|
|
gdev->owner = chip->owner;
|
|
else
|
|
gdev->owner = THIS_MODULE;
|
|
|
|
gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
|
|
if (!gdev->descs) {
|
|
status = -ENOMEM;
|
|
goto err_free_ida;
|
|
}
|
|
|
|
if (chip->ngpio == 0) {
|
|
chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
|
|
status = -EINVAL;
|
|
goto err_free_descs;
|
|
}
|
|
|
|
if (chip->label)
|
|
gdev->label = kstrdup(chip->label, GFP_KERNEL);
|
|
else
|
|
gdev->label = kstrdup("unknown", GFP_KERNEL);
|
|
if (!gdev->label) {
|
|
status = -ENOMEM;
|
|
goto err_free_descs;
|
|
}
|
|
|
|
gdev->ngpio = chip->ngpio;
|
|
gdev->data = data;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
/*
|
|
* TODO: this allocates a Linux GPIO number base in the global
|
|
* GPIO numberspace for this chip. In the long run we want to
|
|
* get *rid* of this numberspace and use only descriptors, but
|
|
* it may be a pipe dream. It will not happen before we get rid
|
|
* of the sysfs interface anyways.
|
|
*/
|
|
if (base < 0) {
|
|
base = gpiochip_find_base(chip->ngpio);
|
|
if (base < 0) {
|
|
status = base;
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
goto err_free_label;
|
|
}
|
|
/*
|
|
* TODO: it should not be necessary to reflect the assigned
|
|
* base outside of the GPIO subsystem. Go over drivers and
|
|
* see if anyone makes use of this, else drop this and assign
|
|
* a poison instead.
|
|
*/
|
|
chip->base = base;
|
|
}
|
|
gdev->base = base;
|
|
|
|
status = gpiodev_add_to_list(gdev);
|
|
if (status) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
goto err_free_label;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
for (i = 0; i < chip->ngpio; i++) {
|
|
struct gpio_desc *desc = &gdev->descs[i];
|
|
|
|
desc->gdev = gdev;
|
|
|
|
/* REVISIT: most hardware initializes GPIOs as inputs (often
|
|
* with pullups enabled) so power usage is minimized. Linux
|
|
* code should set the gpio direction first thing; but until
|
|
* it does, and in case chip->get_direction is not set, we may
|
|
* expose the wrong direction in sysfs.
|
|
*/
|
|
desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PINCTRL
|
|
INIT_LIST_HEAD(&gdev->pin_ranges);
|
|
#endif
|
|
|
|
status = gpiochip_set_desc_names(chip);
|
|
if (status)
|
|
goto err_remove_from_list;
|
|
|
|
status = gpiochip_irqchip_init_valid_mask(chip);
|
|
if (status)
|
|
goto err_remove_from_list;
|
|
|
|
status = of_gpiochip_add(chip);
|
|
if (status)
|
|
goto err_remove_chip;
|
|
|
|
acpi_gpiochip_add(chip);
|
|
|
|
/*
|
|
* By first adding the chardev, and then adding the device,
|
|
* we get a device node entry in sysfs under
|
|
* /sys/bus/gpio/devices/gpiochipN/dev that can be used for
|
|
* coldplug of device nodes and other udev business.
|
|
* We can do this only if gpiolib has been initialized.
|
|
* Otherwise, defer until later.
|
|
*/
|
|
if (gpiolib_initialized) {
|
|
status = gpiochip_setup_dev(gdev);
|
|
if (status)
|
|
goto err_remove_chip;
|
|
}
|
|
return 0;
|
|
|
|
err_remove_chip:
|
|
acpi_gpiochip_remove(chip);
|
|
gpiochip_free_hogs(chip);
|
|
of_gpiochip_remove(chip);
|
|
gpiochip_irqchip_free_valid_mask(chip);
|
|
err_remove_from_list:
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_del(&gdev->list);
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
err_free_label:
|
|
kfree(gdev->label);
|
|
err_free_descs:
|
|
kfree(gdev->descs);
|
|
err_free_ida:
|
|
ida_simple_remove(&gpio_ida, gdev->id);
|
|
err_free_gdev:
|
|
/* failures here can mean systems won't boot... */
|
|
pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
|
|
gdev->base, gdev->base + gdev->ngpio - 1,
|
|
chip->label ? : "generic");
|
|
kfree(gdev);
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_data);
|
|
|
|
/**
|
|
* gpiochip_get_data() - get per-subdriver data for the chip
|
|
*/
|
|
void *gpiochip_get_data(struct gpio_chip *chip)
|
|
{
|
|
return chip->gpiodev->data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_get_data);
|
|
|
|
/**
|
|
* gpiochip_remove() - unregister a gpio_chip
|
|
* @chip: the chip to unregister
|
|
*
|
|
* A gpio_chip with any GPIOs still requested may not be removed.
|
|
*/
|
|
void gpiochip_remove(struct gpio_chip *chip)
|
|
{
|
|
struct gpio_device *gdev = chip->gpiodev;
|
|
struct gpio_desc *desc;
|
|
unsigned long flags;
|
|
unsigned i;
|
|
bool requested = false;
|
|
|
|
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
|
|
gpiochip_sysfs_unregister(gdev);
|
|
gpiochip_free_hogs(chip);
|
|
/* Numb the device, cancelling all outstanding operations */
|
|
gdev->chip = NULL;
|
|
gpiochip_irqchip_remove(chip);
|
|
acpi_gpiochip_remove(chip);
|
|
gpiochip_remove_pin_ranges(chip);
|
|
of_gpiochip_remove(chip);
|
|
/*
|
|
* We accept no more calls into the driver from this point, so
|
|
* NULL the driver data pointer
|
|
*/
|
|
gdev->data = NULL;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
for (i = 0; i < gdev->ngpio; i++) {
|
|
desc = &gdev->descs[i];
|
|
if (test_bit(FLAG_REQUESTED, &desc->flags))
|
|
requested = true;
|
|
}
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
if (requested)
|
|
dev_crit(&gdev->dev,
|
|
"REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
|
|
|
|
/*
|
|
* The gpiochip side puts its use of the device to rest here:
|
|
* if there are no userspace clients, the chardev and device will
|
|
* be removed, else it will be dangling until the last user is
|
|
* gone.
|
|
*/
|
|
cdev_del(&gdev->chrdev);
|
|
device_del(&gdev->dev);
|
|
put_device(&gdev->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_remove);
|
|
|
|
static void devm_gpio_chip_release(struct device *dev, void *res)
|
|
{
|
|
struct gpio_chip *chip = *(struct gpio_chip **)res;
|
|
|
|
gpiochip_remove(chip);
|
|
}
|
|
|
|
static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
|
|
|
|
{
|
|
struct gpio_chip **r = res;
|
|
|
|
if (!r || !*r) {
|
|
WARN_ON(!r || !*r);
|
|
return 0;
|
|
}
|
|
|
|
return *r == data;
|
|
}
|
|
|
|
/**
|
|
* devm_gpiochip_add_data() - Resource manager piochip_add_data()
|
|
* @dev: the device pointer on which irq_chip belongs to.
|
|
* @chip: the chip to register, with chip->base initialized
|
|
* Context: potentially before irqs will work
|
|
*
|
|
* Returns a negative errno if the chip can't be registered, such as
|
|
* because the chip->base is invalid or already associated with a
|
|
* different chip. Otherwise it returns zero as a success code.
|
|
*
|
|
* The gpio chip automatically be released when the device is unbound.
|
|
*/
|
|
int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
|
|
void *data)
|
|
{
|
|
struct gpio_chip **ptr;
|
|
int ret;
|
|
|
|
ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
|
|
GFP_KERNEL);
|
|
if (!ptr)
|
|
return -ENOMEM;
|
|
|
|
ret = gpiochip_add_data(chip, data);
|
|
if (ret < 0) {
|
|
devres_free(ptr);
|
|
return ret;
|
|
}
|
|
|
|
*ptr = chip;
|
|
devres_add(dev, ptr);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
|
|
|
|
/**
|
|
* devm_gpiochip_remove() - Resource manager of gpiochip_remove()
|
|
* @dev: device for which which resource was allocated
|
|
* @chip: the chip to remove
|
|
*
|
|
* A gpio_chip with any GPIOs still requested may not be removed.
|
|
*/
|
|
void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
|
|
{
|
|
int ret;
|
|
|
|
ret = devres_release(dev, devm_gpio_chip_release,
|
|
devm_gpio_chip_match, chip);
|
|
if (!ret)
|
|
WARN_ON(ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
|
|
|
|
/**
|
|
* gpiochip_find() - iterator for locating a specific gpio_chip
|
|
* @data: data to pass to match function
|
|
* @callback: Callback function to check gpio_chip
|
|
*
|
|
* Similar to bus_find_device. It returns a reference to a gpio_chip as
|
|
* determined by a user supplied @match callback. The callback should return
|
|
* 0 if the device doesn't match and non-zero if it does. If the callback is
|
|
* non-zero, this function will return to the caller and not iterate over any
|
|
* more gpio_chips.
|
|
*/
|
|
struct gpio_chip *gpiochip_find(void *data,
|
|
int (*match)(struct gpio_chip *chip,
|
|
void *data))
|
|
{
|
|
struct gpio_device *gdev;
|
|
struct gpio_chip *chip = NULL;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_for_each_entry(gdev, &gpio_devices, list)
|
|
if (gdev->chip && match(gdev->chip, data)) {
|
|
chip = gdev->chip;
|
|
break;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
return chip;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_find);
|
|
|
|
static int gpiochip_match_name(struct gpio_chip *chip, void *data)
|
|
{
|
|
const char *name = data;
|
|
|
|
return !strcmp(chip->label, name);
|
|
}
|
|
|
|
static struct gpio_chip *find_chip_by_name(const char *name)
|
|
{
|
|
return gpiochip_find((void *)name, gpiochip_match_name);
|
|
}
|
|
|
|
#ifdef CONFIG_GPIOLIB_IRQCHIP
|
|
|
|
/*
|
|
* The following is irqchip helper code for gpiochips.
|
|
*/
|
|
|
|
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
|
|
{
|
|
int i;
|
|
|
|
if (!gpiochip->irq_need_valid_mask)
|
|
return 0;
|
|
|
|
gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
|
|
sizeof(long), GFP_KERNEL);
|
|
if (!gpiochip->irq_valid_mask)
|
|
return -ENOMEM;
|
|
|
|
/* Assume by default all GPIOs are valid */
|
|
for (i = 0; i < gpiochip->ngpio; i++)
|
|
set_bit(i, gpiochip->irq_valid_mask);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
|
|
{
|
|
kfree(gpiochip->irq_valid_mask);
|
|
gpiochip->irq_valid_mask = NULL;
|
|
}
|
|
|
|
static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
|
|
unsigned int offset)
|
|
{
|
|
/* No mask means all valid */
|
|
if (likely(!gpiochip->irq_valid_mask))
|
|
return true;
|
|
return test_bit(offset, gpiochip->irq_valid_mask);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
|
|
* @gpiochip: the gpiochip to set the irqchip chain to
|
|
* @irqchip: the irqchip to chain to the gpiochip
|
|
* @parent_irq: the irq number corresponding to the parent IRQ for this
|
|
* chained irqchip
|
|
* @parent_handler: the parent interrupt handler for the accumulated IRQ
|
|
* coming out of the gpiochip. If the interrupt is nested rather than
|
|
* cascaded, pass NULL in this handler argument
|
|
*/
|
|
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
|
|
struct irq_chip *irqchip,
|
|
int parent_irq,
|
|
irq_flow_handler_t parent_handler)
|
|
{
|
|
unsigned int offset;
|
|
|
|
if (!gpiochip->irqdomain) {
|
|
chip_err(gpiochip, "called %s before setting up irqchip\n",
|
|
__func__);
|
|
return;
|
|
}
|
|
|
|
if (parent_handler) {
|
|
if (gpiochip->can_sleep) {
|
|
chip_err(gpiochip,
|
|
"you cannot have chained interrupts on a "
|
|
"chip that may sleep\n");
|
|
return;
|
|
}
|
|
/*
|
|
* The parent irqchip is already using the chip_data for this
|
|
* irqchip, so our callbacks simply use the handler_data.
|
|
*/
|
|
irq_set_chained_handler_and_data(parent_irq, parent_handler,
|
|
gpiochip);
|
|
|
|
gpiochip->irq_parent = parent_irq;
|
|
}
|
|
|
|
/* Set the parent IRQ for all affected IRQs */
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++) {
|
|
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
|
|
continue;
|
|
irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
|
|
parent_irq);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
|
|
|
|
/**
|
|
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
|
|
* @d: the irqdomain used by this irqchip
|
|
* @irq: the global irq number used by this GPIO irqchip irq
|
|
* @hwirq: the local IRQ/GPIO line offset on this gpiochip
|
|
*
|
|
* This function will set up the mapping for a certain IRQ line on a
|
|
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
|
|
* stored inside the gpiochip.
|
|
*/
|
|
static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
|
|
irq_hw_number_t hwirq)
|
|
{
|
|
struct gpio_chip *chip = d->host_data;
|
|
|
|
irq_set_chip_data(irq, chip);
|
|
/*
|
|
* This lock class tells lockdep that GPIO irqs are in a different
|
|
* category than their parents, so it won't report false recursion.
|
|
*/
|
|
irq_set_lockdep_class(irq, chip->lock_key);
|
|
irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
|
|
/* Chips that can sleep need nested thread handlers */
|
|
if (chip->can_sleep && !chip->irq_not_threaded)
|
|
irq_set_nested_thread(irq, 1);
|
|
irq_set_noprobe(irq);
|
|
|
|
/*
|
|
* No set-up of the hardware will happen if IRQ_TYPE_NONE
|
|
* is passed as default type.
|
|
*/
|
|
if (chip->irq_default_type != IRQ_TYPE_NONE)
|
|
irq_set_irq_type(irq, chip->irq_default_type);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
|
|
{
|
|
struct gpio_chip *chip = d->host_data;
|
|
|
|
if (chip->can_sleep)
|
|
irq_set_nested_thread(irq, 0);
|
|
irq_set_chip_and_handler(irq, NULL, NULL);
|
|
irq_set_chip_data(irq, NULL);
|
|
}
|
|
|
|
static const struct irq_domain_ops gpiochip_domain_ops = {
|
|
.map = gpiochip_irq_map,
|
|
.unmap = gpiochip_irq_unmap,
|
|
/* Virtually all GPIO irqchips are twocell:ed */
|
|
.xlate = irq_domain_xlate_twocell,
|
|
};
|
|
|
|
static int gpiochip_irq_reqres(struct irq_data *d)
|
|
{
|
|
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
|
|
|
|
if (!try_module_get(chip->gpiodev->owner))
|
|
return -ENODEV;
|
|
|
|
if (gpiochip_lock_as_irq(chip, d->hwirq)) {
|
|
chip_err(chip,
|
|
"unable to lock HW IRQ %lu for IRQ\n",
|
|
d->hwirq);
|
|
module_put(chip->gpiodev->owner);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void gpiochip_irq_relres(struct irq_data *d)
|
|
{
|
|
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
|
|
|
|
gpiochip_unlock_as_irq(chip, d->hwirq);
|
|
module_put(chip->gpiodev->owner);
|
|
}
|
|
|
|
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
return irq_find_mapping(chip->irqdomain, offset);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
|
|
* @gpiochip: the gpiochip to remove the irqchip from
|
|
*
|
|
* This is called only from gpiochip_remove()
|
|
*/
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
|
|
{
|
|
unsigned int offset;
|
|
|
|
acpi_gpiochip_free_interrupts(gpiochip);
|
|
|
|
if (gpiochip->irq_parent) {
|
|
irq_set_chained_handler(gpiochip->irq_parent, NULL);
|
|
irq_set_handler_data(gpiochip->irq_parent, NULL);
|
|
}
|
|
|
|
/* Remove all IRQ mappings and delete the domain */
|
|
if (gpiochip->irqdomain) {
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++) {
|
|
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
|
|
continue;
|
|
irq_dispose_mapping(
|
|
irq_find_mapping(gpiochip->irqdomain, offset));
|
|
}
|
|
irq_domain_remove(gpiochip->irqdomain);
|
|
}
|
|
|
|
if (gpiochip->irqchip) {
|
|
gpiochip->irqchip->irq_request_resources = NULL;
|
|
gpiochip->irqchip->irq_release_resources = NULL;
|
|
gpiochip->irqchip = NULL;
|
|
}
|
|
|
|
gpiochip_irqchip_free_valid_mask(gpiochip);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_irqchip_add() - adds an irqchip to a gpiochip
|
|
* @gpiochip: the gpiochip to add the irqchip to
|
|
* @irqchip: the irqchip to add to the gpiochip
|
|
* @first_irq: if not dynamically assigned, the base (first) IRQ to
|
|
* allocate gpiochip irqs from
|
|
* @handler: the irq handler to use (often a predefined irq core function)
|
|
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
|
|
* to have the core avoid setting up any default type in the hardware.
|
|
* @lock_key: lockdep class
|
|
*
|
|
* This function closely associates a certain irqchip with a certain
|
|
* gpiochip, providing an irq domain to translate the local IRQs to
|
|
* global irqs in the gpiolib core, and making sure that the gpiochip
|
|
* is passed as chip data to all related functions. Driver callbacks
|
|
* need to use gpiochip_get_data() to get their local state containers back
|
|
* from the gpiochip passed as chip data. An irqdomain will be stored
|
|
* in the gpiochip that shall be used by the driver to handle IRQ number
|
|
* translation. The gpiochip will need to be initialized and registered
|
|
* before calling this function.
|
|
*
|
|
* This function will handle two cell:ed simple IRQs and assumes all
|
|
* the pins on the gpiochip can generate a unique IRQ. Everything else
|
|
* need to be open coded.
|
|
*/
|
|
int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
|
|
struct irq_chip *irqchip,
|
|
unsigned int first_irq,
|
|
irq_flow_handler_t handler,
|
|
unsigned int type,
|
|
struct lock_class_key *lock_key)
|
|
{
|
|
struct device_node *of_node;
|
|
bool irq_base_set = false;
|
|
unsigned int offset;
|
|
unsigned irq_base = 0;
|
|
|
|
if (!gpiochip || !irqchip)
|
|
return -EINVAL;
|
|
|
|
if (!gpiochip->parent) {
|
|
pr_err("missing gpiochip .dev parent pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
of_node = gpiochip->parent->of_node;
|
|
#ifdef CONFIG_OF_GPIO
|
|
/*
|
|
* If the gpiochip has an assigned OF node this takes precedence
|
|
* FIXME: get rid of this and use gpiochip->parent->of_node
|
|
* everywhere
|
|
*/
|
|
if (gpiochip->of_node)
|
|
of_node = gpiochip->of_node;
|
|
#endif
|
|
/*
|
|
* Specifying a default trigger is a terrible idea if DT or ACPI is
|
|
* used to configure the interrupts, as you may end-up with
|
|
* conflicting triggers. Tell the user, and reset to NONE.
|
|
*/
|
|
if (WARN(of_node && type != IRQ_TYPE_NONE,
|
|
"%s: Ignoring %d default trigger\n", of_node->full_name, type))
|
|
type = IRQ_TYPE_NONE;
|
|
if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
|
|
acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
|
|
"Ignoring %d default trigger\n", type);
|
|
type = IRQ_TYPE_NONE;
|
|
}
|
|
|
|
gpiochip->irqchip = irqchip;
|
|
gpiochip->irq_handler = handler;
|
|
gpiochip->irq_default_type = type;
|
|
gpiochip->to_irq = gpiochip_to_irq;
|
|
gpiochip->lock_key = lock_key;
|
|
gpiochip->irqdomain = irq_domain_add_simple(of_node,
|
|
gpiochip->ngpio, first_irq,
|
|
&gpiochip_domain_ops, gpiochip);
|
|
if (!gpiochip->irqdomain) {
|
|
gpiochip->irqchip = NULL;
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* It is possible for a driver to override this, but only if the
|
|
* alternative functions are both implemented.
|
|
*/
|
|
if (!irqchip->irq_request_resources &&
|
|
!irqchip->irq_release_resources) {
|
|
irqchip->irq_request_resources = gpiochip_irq_reqres;
|
|
irqchip->irq_release_resources = gpiochip_irq_relres;
|
|
}
|
|
|
|
/*
|
|
* Prepare the mapping since the irqchip shall be orthogonal to
|
|
* any gpiochip calls. If the first_irq was zero, this is
|
|
* necessary to allocate descriptors for all IRQs.
|
|
*/
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++) {
|
|
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
|
|
continue;
|
|
irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
|
|
if (!irq_base_set) {
|
|
/*
|
|
* Store the base into the gpiochip to be used when
|
|
* unmapping the irqs.
|
|
*/
|
|
gpiochip->irq_base = irq_base;
|
|
irq_base_set = true;
|
|
}
|
|
}
|
|
|
|
acpi_gpiochip_request_interrupts(gpiochip);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
|
|
|
|
#else /* CONFIG_GPIOLIB_IRQCHIP */
|
|
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
|
|
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
|
|
{ }
|
|
|
|
#endif /* CONFIG_GPIOLIB_IRQCHIP */
|
|
|
|
/**
|
|
* gpiochip_generic_request() - request the gpio function for a pin
|
|
* @chip: the gpiochip owning the GPIO
|
|
* @offset: the offset of the GPIO to request for GPIO function
|
|
*/
|
|
int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
return pinctrl_request_gpio(chip->gpiodev->base + offset);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_generic_request);
|
|
|
|
/**
|
|
* gpiochip_generic_free() - free the gpio function from a pin
|
|
* @chip: the gpiochip to request the gpio function for
|
|
* @offset: the offset of the GPIO to free from GPIO function
|
|
*/
|
|
void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
pinctrl_free_gpio(chip->gpiodev->base + offset);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_generic_free);
|
|
|
|
#ifdef CONFIG_PINCTRL
|
|
|
|
/**
|
|
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
|
|
* @chip: the gpiochip to add the range for
|
|
* @pctldev: the pin controller to map to
|
|
* @gpio_offset: the start offset in the current gpio_chip number space
|
|
* @pin_group: name of the pin group inside the pin controller
|
|
*/
|
|
int gpiochip_add_pingroup_range(struct gpio_chip *chip,
|
|
struct pinctrl_dev *pctldev,
|
|
unsigned int gpio_offset, const char *pin_group)
|
|
{
|
|
struct gpio_pin_range *pin_range;
|
|
struct gpio_device *gdev = chip->gpiodev;
|
|
int ret;
|
|
|
|
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
|
|
if (!pin_range) {
|
|
chip_err(chip, "failed to allocate pin ranges\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Use local offset as range ID */
|
|
pin_range->range.id = gpio_offset;
|
|
pin_range->range.gc = chip;
|
|
pin_range->range.name = chip->label;
|
|
pin_range->range.base = gdev->base + gpio_offset;
|
|
pin_range->pctldev = pctldev;
|
|
|
|
ret = pinctrl_get_group_pins(pctldev, pin_group,
|
|
&pin_range->range.pins,
|
|
&pin_range->range.npins);
|
|
if (ret < 0) {
|
|
kfree(pin_range);
|
|
return ret;
|
|
}
|
|
|
|
pinctrl_add_gpio_range(pctldev, &pin_range->range);
|
|
|
|
chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
|
|
gpio_offset, gpio_offset + pin_range->range.npins - 1,
|
|
pinctrl_dev_get_devname(pctldev), pin_group);
|
|
|
|
list_add_tail(&pin_range->node, &gdev->pin_ranges);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
|
|
|
|
/**
|
|
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
|
|
* @chip: the gpiochip to add the range for
|
|
* @pinctrl_name: the dev_name() of the pin controller to map to
|
|
* @gpio_offset: the start offset in the current gpio_chip number space
|
|
* @pin_offset: the start offset in the pin controller number space
|
|
* @npins: the number of pins from the offset of each pin space (GPIO and
|
|
* pin controller) to accumulate in this range
|
|
*/
|
|
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
|
|
unsigned int gpio_offset, unsigned int pin_offset,
|
|
unsigned int npins)
|
|
{
|
|
struct gpio_pin_range *pin_range;
|
|
struct gpio_device *gdev = chip->gpiodev;
|
|
int ret;
|
|
|
|
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
|
|
if (!pin_range) {
|
|
chip_err(chip, "failed to allocate pin ranges\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Use local offset as range ID */
|
|
pin_range->range.id = gpio_offset;
|
|
pin_range->range.gc = chip;
|
|
pin_range->range.name = chip->label;
|
|
pin_range->range.base = gdev->base + gpio_offset;
|
|
pin_range->range.pin_base = pin_offset;
|
|
pin_range->range.npins = npins;
|
|
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
|
|
&pin_range->range);
|
|
if (IS_ERR(pin_range->pctldev)) {
|
|
ret = PTR_ERR(pin_range->pctldev);
|
|
chip_err(chip, "could not create pin range\n");
|
|
kfree(pin_range);
|
|
return ret;
|
|
}
|
|
chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
|
|
gpio_offset, gpio_offset + npins - 1,
|
|
pinctl_name,
|
|
pin_offset, pin_offset + npins - 1);
|
|
|
|
list_add_tail(&pin_range->node, &gdev->pin_ranges);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
|
|
|
|
/**
|
|
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
|
|
* @chip: the chip to remove all the mappings for
|
|
*/
|
|
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
|
|
{
|
|
struct gpio_pin_range *pin_range, *tmp;
|
|
struct gpio_device *gdev = chip->gpiodev;
|
|
|
|
list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
|
|
list_del(&pin_range->node);
|
|
pinctrl_remove_gpio_range(pin_range->pctldev,
|
|
&pin_range->range);
|
|
kfree(pin_range);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
|
|
|
|
#endif /* CONFIG_PINCTRL */
|
|
|
|
/* These "optional" allocation calls help prevent drivers from stomping
|
|
* on each other, and help provide better diagnostics in debugfs.
|
|
* They're called even less than the "set direction" calls.
|
|
*/
|
|
static int __gpiod_request(struct gpio_desc *desc, const char *label)
|
|
{
|
|
struct gpio_chip *chip = desc->gdev->chip;
|
|
int status;
|
|
unsigned long flags;
|
|
bool hogged = false;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
/* NOTE: gpio_request() can be called in early boot,
|
|
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
|
|
*/
|
|
|
|
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
|
|
desc_set_label(desc, label ? : "?");
|
|
status = 0;
|
|
} else {
|
|
if (test_bit(FLAG_IS_HOGGED, &desc->flags)) {
|
|
hogged = true;
|
|
desc_set_label(desc, label ? : "?");
|
|
clear_bit(FLAG_IS_HOGGED, &desc->flags);
|
|
status = 0;
|
|
} else {
|
|
status = -EBUSY;
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
if (chip->request && !hogged) {
|
|
/* chip->request may sleep */
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
status = chip->request(chip, gpio_chip_hwgpio(desc));
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
if (status < 0) {
|
|
desc_set_label(desc, NULL);
|
|
clear_bit(FLAG_REQUESTED, &desc->flags);
|
|
goto done;
|
|
}
|
|
}
|
|
if (chip->get_direction) {
|
|
/* chip->get_direction may sleep */
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
gpiod_get_direction(desc);
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
done:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return status;
|
|
}
|
|
|
|
/*
|
|
* This descriptor validation needs to be inserted verbatim into each
|
|
* function taking a descriptor, so we need to use a preprocessor
|
|
* macro to avoid endless duplication. If the desc is NULL it is an
|
|
* optional GPIO and calls should just bail out.
|
|
*/
|
|
#define VALIDATE_DESC(desc) do { \
|
|
if (!desc) \
|
|
return 0; \
|
|
if (IS_ERR(desc)) { \
|
|
pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
|
|
return PTR_ERR(desc); \
|
|
} \
|
|
if (!desc->gdev) { \
|
|
pr_warn("%s: invalid GPIO (no device)\n", __func__); \
|
|
return -EINVAL; \
|
|
} \
|
|
if ( !desc->gdev->chip ) { \
|
|
dev_warn(&desc->gdev->dev, \
|
|
"%s: backing chip is gone\n", __func__); \
|
|
return 0; \
|
|
} } while (0)
|
|
|
|
#define VALIDATE_DESC_VOID(desc) do { \
|
|
if (!desc) \
|
|
return; \
|
|
if (IS_ERR(desc)) { \
|
|
pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
|
|
return; \
|
|
} \
|
|
if (!desc->gdev) { \
|
|
pr_warn("%s: invalid GPIO (no device)\n", __func__); \
|
|
return; \
|
|
} \
|
|
if (!desc->gdev->chip) { \
|
|
dev_warn(&desc->gdev->dev, \
|
|
"%s: backing chip is gone\n", __func__); \
|
|
return; \
|
|
} } while (0)
|
|
|
|
|
|
int gpiod_request(struct gpio_desc *desc, const char *label)
|
|
{
|
|
int status = -EPROBE_DEFER;
|
|
struct gpio_device *gdev;
|
|
|
|
VALIDATE_DESC(desc);
|
|
gdev = desc->gdev;
|
|
|
|
if (try_module_get(gdev->owner)) {
|
|
status = __gpiod_request(desc, label);
|
|
if (status < 0)
|
|
module_put(gdev->owner);
|
|
else
|
|
get_device(&gdev->dev);
|
|
}
|
|
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
|
|
static bool __gpiod_free(struct gpio_desc *desc)
|
|
{
|
|
bool ret = false;
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
|
|
might_sleep();
|
|
|
|
gpiod_unexport(desc);
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
chip = desc->gdev->chip;
|
|
if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
|
|
if (chip->free) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
might_sleep_if(chip->can_sleep);
|
|
chip->free(chip, gpio_chip_hwgpio(desc));
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
desc_set_label(desc, NULL);
|
|
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
clear_bit(FLAG_REQUESTED, &desc->flags);
|
|
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
clear_bit(FLAG_IS_HOGGED, &desc->flags);
|
|
ret = true;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
void gpiod_free(struct gpio_desc *desc)
|
|
{
|
|
if (desc && desc->gdev && __gpiod_free(desc)) {
|
|
module_put(desc->gdev->owner);
|
|
put_device(&desc->gdev->dev);
|
|
} else {
|
|
WARN_ON(extra_checks);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gpiochip_is_requested - return string iff signal was requested
|
|
* @chip: controller managing the signal
|
|
* @offset: of signal within controller's 0..(ngpio - 1) range
|
|
*
|
|
* Returns NULL if the GPIO is not currently requested, else a string.
|
|
* The string returned is the label passed to gpio_request(); if none has been
|
|
* passed it is a meaningless, non-NULL constant.
|
|
*
|
|
* This function is for use by GPIO controller drivers. The label can
|
|
* help with diagnostics, and knowing that the signal is used as a GPIO
|
|
* can help avoid accidentally multiplexing it to another controller.
|
|
*/
|
|
const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
struct gpio_desc *desc;
|
|
|
|
if (offset >= chip->ngpio)
|
|
return NULL;
|
|
|
|
desc = &chip->gpiodev->descs[offset];
|
|
|
|
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
|
|
return NULL;
|
|
return desc->label;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
|
|
|
|
/**
|
|
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
|
|
* @desc: GPIO descriptor to request
|
|
* @label: label for the GPIO
|
|
*
|
|
* Function allows GPIO chip drivers to request and use their own GPIO
|
|
* descriptors via gpiolib API. Difference to gpiod_request() is that this
|
|
* function will not increase reference count of the GPIO chip module. This
|
|
* allows the GPIO chip module to be unloaded as needed (we assume that the
|
|
* GPIO chip driver handles freeing the GPIOs it has requested).
|
|
*/
|
|
struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
|
|
const char *label)
|
|
{
|
|
struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
|
|
int err;
|
|
|
|
if (IS_ERR(desc)) {
|
|
chip_err(chip, "failed to get GPIO descriptor\n");
|
|
return desc;
|
|
}
|
|
|
|
err = __gpiod_request(desc, label);
|
|
if (err < 0)
|
|
return ERR_PTR(err);
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
|
|
|
|
/**
|
|
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
|
|
* @desc: GPIO descriptor to free
|
|
*
|
|
* Function frees the given GPIO requested previously with
|
|
* gpiochip_request_own_desc().
|
|
*/
|
|
void gpiochip_free_own_desc(struct gpio_desc *desc)
|
|
{
|
|
if (desc)
|
|
__gpiod_free(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
|
|
|
|
/*
|
|
* Drivers MUST set GPIO direction before making get/set calls. In
|
|
* some cases this is done in early boot, before IRQs are enabled.
|
|
*
|
|
* As a rule these aren't called more than once (except for drivers
|
|
* using the open-drain emulation idiom) so these are natural places
|
|
* to accumulate extra debugging checks. Note that we can't (yet)
|
|
* rely on gpio_request() having been called beforehand.
|
|
*/
|
|
|
|
/**
|
|
* gpiod_direction_input - set the GPIO direction to input
|
|
* @desc: GPIO to set to input
|
|
*
|
|
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
|
|
* be called safely on it.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_input(struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
|
|
VALIDATE_DESC(desc);
|
|
chip = desc->gdev->chip;
|
|
|
|
if (!chip->get || !chip->direction_input) {
|
|
gpiod_warn(desc,
|
|
"%s: missing get() or direction_input() operations\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
|
|
if (status == 0)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
|
|
trace_gpio_direction(desc_to_gpio(desc), 1, status);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_input);
|
|
|
|
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
|
|
{
|
|
struct gpio_chip *gc = desc->gdev->chip;
|
|
int ret;
|
|
|
|
/* GPIOs used for IRQs shall not be set as output */
|
|
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
|
|
gpiod_err(desc,
|
|
"%s: tried to set a GPIO tied to an IRQ as output\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
|
|
/* First see if we can enable open drain in hardware */
|
|
if (gc->set_single_ended) {
|
|
ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
|
|
LINE_MODE_OPEN_DRAIN);
|
|
if (!ret)
|
|
goto set_output_value;
|
|
}
|
|
/* Emulate open drain by not actively driving the line high */
|
|
if (value)
|
|
return gpiod_direction_input(desc);
|
|
}
|
|
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
|
|
if (gc->set_single_ended) {
|
|
ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
|
|
LINE_MODE_OPEN_SOURCE);
|
|
if (!ret)
|
|
goto set_output_value;
|
|
}
|
|
/* Emulate open source by not actively driving the line low */
|
|
if (!value)
|
|
return gpiod_direction_input(desc);
|
|
} else {
|
|
/* Make sure to disable open drain/source hardware, if any */
|
|
if (gc->set_single_ended)
|
|
gc->set_single_ended(gc,
|
|
gpio_chip_hwgpio(desc),
|
|
LINE_MODE_PUSH_PULL);
|
|
}
|
|
|
|
set_output_value:
|
|
if (!gc->set || !gc->direction_output) {
|
|
gpiod_warn(desc,
|
|
"%s: missing set() or direction_output() operations\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
|
|
if (!ret)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
trace_gpio_value(desc_to_gpio(desc), 0, value);
|
|
trace_gpio_direction(desc_to_gpio(desc), 0, ret);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* gpiod_direction_output_raw - set the GPIO direction to output
|
|
* @desc: GPIO to set to output
|
|
* @value: initial output value of the GPIO
|
|
*
|
|
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
|
|
* be called safely on it. The initial value of the output must be specified
|
|
* as raw value on the physical line without regard for the ACTIVE_LOW status.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
|
|
{
|
|
VALIDATE_DESC(desc);
|
|
return _gpiod_direction_output_raw(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
|
|
|
|
/**
|
|
* gpiod_direction_output - set the GPIO direction to output
|
|
* @desc: GPIO to set to output
|
|
* @value: initial output value of the GPIO
|
|
*
|
|
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
|
|
* be called safely on it. The initial value of the output must be specified
|
|
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_output(struct gpio_desc *desc, int value)
|
|
{
|
|
VALIDATE_DESC(desc);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
return _gpiod_direction_output_raw(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_output);
|
|
|
|
/**
|
|
* gpiod_timestamp_control - Enable/Disable timstamping for GPIO
|
|
* @desc: GPIO for which to Enable/Disable Timestamp
|
|
* @enable: Enable/Disable timestamp
|
|
*
|
|
* Enable or Disable timestamping feature for given GPIO
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_timestamp_control(struct gpio_desc *desc, int enable)
|
|
{
|
|
struct gpio_chip *chip;
|
|
|
|
VALIDATE_DESC(desc);
|
|
chip = desc->gdev->chip;
|
|
if (!chip->timestamp_control) {
|
|
gpiod_warn(desc, "%s: missing timestamp_control operations\n",
|
|
__func__);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
return chip->timestamp_control(chip, gpio_chip_hwgpio(desc), enable);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_timestamp_control);
|
|
|
|
/**
|
|
* gpiod_timestamp_read - Read timstamp value for GPIO
|
|
* @desc: GPIO to read timestamp value
|
|
* @ts: data where to store the timestamp
|
|
*
|
|
* Read timestamp value for given GPIO
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_timestamp_read(struct gpio_desc *desc, u64 *ts)
|
|
{
|
|
struct gpio_chip *chip;
|
|
u64 gpio_ts;
|
|
int ret;
|
|
|
|
VALIDATE_DESC(desc);
|
|
chip = desc->gdev->chip;
|
|
if (!chip->timestamp_read) {
|
|
gpiod_warn(desc, "%s: missing timestamp_read operations\n",
|
|
__func__);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
ret = chip->timestamp_read(chip, gpio_chip_hwgpio(desc), &gpio_ts);
|
|
*ts = gpio_ts;
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_timestamp_read);
|
|
|
|
/**
|
|
* gpiod_set_debounce - sets @debounce time for a @gpio
|
|
* @gpio: the gpio to set debounce time
|
|
* @debounce: debounce time is microseconds
|
|
*
|
|
* returns -ENOTSUPP if the controller does not support setting
|
|
* debounce.
|
|
*/
|
|
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
|
|
{
|
|
struct gpio_chip *chip;
|
|
|
|
VALIDATE_DESC(desc);
|
|
chip = desc->gdev->chip;
|
|
if (!chip->set || !chip->set_debounce) {
|
|
gpiod_dbg(desc,
|
|
"%s: missing set() or set_debounce() operations\n",
|
|
__func__);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
|
|
|
|
/**
|
|
* gpiod_is_active_low - test whether a GPIO is active-low or not
|
|
* @desc: the gpio descriptor to test
|
|
*
|
|
* Returns 1 if the GPIO is active-low, 0 otherwise.
|
|
*/
|
|
int gpiod_is_active_low(const struct gpio_desc *desc)
|
|
{
|
|
VALIDATE_DESC(desc);
|
|
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
|
|
|
|
/**
|
|
* gpiod_is_enabled - Test whether a GPIO is enabled or not.
|
|
* @desc: the gpio descriptor to check.
|
|
*
|
|
* Returns 1 if the GPIO is enabled, 0 if not and error if any
|
|
* failure.
|
|
*/
|
|
int gpiod_is_enabled(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip = gpiod_to_chip(desc);
|
|
|
|
if (!chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!chip->is_enabled) {
|
|
gpiod_dbg(desc, "%s: missing is_enabled() ops\n", __func__);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
return chip->is_enabled(chip, gpio_chip_hwgpio(desc));
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_is_enabled);
|
|
|
|
/* I/O calls are only valid after configuration completed; the relevant
|
|
* "is this a valid GPIO" error checks should already have been done.
|
|
*
|
|
* "Get" operations are often inlinable as reading a pin value register,
|
|
* and masking the relevant bit in that register.
|
|
*
|
|
* When "set" operations are inlinable, they involve writing that mask to
|
|
* one register to set a low value, or a different register to set it high.
|
|
* Otherwise locking is needed, so there may be little value to inlining.
|
|
*
|
|
*------------------------------------------------------------------------
|
|
*
|
|
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
|
|
* have requested the GPIO. That can include implicit requesting by
|
|
* a direction setting call. Marking a gpio as requested locks its chip
|
|
* in memory, guaranteeing that these table lookups need no more locking
|
|
* and that gpiochip_remove() will fail.
|
|
*
|
|
* REVISIT when debugging, consider adding some instrumentation to ensure
|
|
* that the GPIO was actually requested.
|
|
*/
|
|
|
|
static int _gpiod_get_raw_value(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
int offset;
|
|
int value;
|
|
|
|
chip = desc->gdev->chip;
|
|
offset = gpio_chip_hwgpio(desc);
|
|
value = chip->get ? chip->get(chip, offset) : -EIO;
|
|
value = value < 0 ? value : !!value;
|
|
trace_gpio_value(desc_to_gpio(desc), 1, value);
|
|
return value;
|
|
}
|
|
|
|
/**
|
|
* gpiod_get_raw_value() - return a gpio's raw value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
|
|
* its ACTIVE_LOW status, or negative errno on failure.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
int gpiod_get_raw_value(const struct gpio_desc *desc)
|
|
{
|
|
VALIDATE_DESC(desc);
|
|
/* Should be using gpiod_get_raw_value_cansleep() */
|
|
WARN_ON(desc->gdev->chip->can_sleep);
|
|
return _gpiod_get_raw_value(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
|
|
|
|
/**
|
|
* gpiod_get_value() - return a gpio's value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
|
|
* account, or negative errno on failure.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
int gpiod_get_value(const struct gpio_desc *desc)
|
|
{
|
|
int value;
|
|
|
|
VALIDATE_DESC(desc);
|
|
/* Should be using gpiod_get_value_cansleep() */
|
|
WARN_ON(desc->gdev->chip->can_sleep);
|
|
|
|
value = _gpiod_get_raw_value(desc);
|
|
if (value < 0)
|
|
return value;
|
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_value);
|
|
|
|
/*
|
|
* _gpio_set_open_drain_value() - Set the open drain gpio's value.
|
|
* @desc: gpio descriptor whose state need to be set.
|
|
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
|
|
*/
|
|
static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
int err = 0;
|
|
struct gpio_chip *chip = desc->gdev->chip;
|
|
int offset = gpio_chip_hwgpio(desc);
|
|
|
|
if (value) {
|
|
err = chip->direction_input(chip, offset);
|
|
if (!err)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
} else {
|
|
err = chip->direction_output(chip, offset, 0);
|
|
if (!err)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
trace_gpio_direction(desc_to_gpio(desc), value, err);
|
|
if (err < 0)
|
|
gpiod_err(desc,
|
|
"%s: Error in set_value for open drain err %d\n",
|
|
__func__, err);
|
|
}
|
|
|
|
/*
|
|
* _gpio_set_open_source_value() - Set the open source gpio's value.
|
|
* @desc: gpio descriptor whose state need to be set.
|
|
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
|
|
*/
|
|
static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
int err = 0;
|
|
struct gpio_chip *chip = desc->gdev->chip;
|
|
int offset = gpio_chip_hwgpio(desc);
|
|
|
|
if (value) {
|
|
err = chip->direction_output(chip, offset, 1);
|
|
if (!err)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
} else {
|
|
err = chip->direction_input(chip, offset);
|
|
if (!err)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
trace_gpio_direction(desc_to_gpio(desc), !value, err);
|
|
if (err < 0)
|
|
gpiod_err(desc,
|
|
"%s: Error in set_value for open source err %d\n",
|
|
__func__, err);
|
|
}
|
|
|
|
static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
struct gpio_chip *chip;
|
|
|
|
chip = desc->gdev->chip;
|
|
trace_gpio_value(desc_to_gpio(desc), 0, value);
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
|
|
_gpio_set_open_drain_value(desc, value);
|
|
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
|
|
_gpio_set_open_source_value(desc, value);
|
|
else
|
|
chip->set(chip, gpio_chip_hwgpio(desc), value);
|
|
}
|
|
|
|
/*
|
|
* set multiple outputs on the same chip;
|
|
* use the chip's set_multiple function if available;
|
|
* otherwise set the outputs sequentially;
|
|
* @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
|
|
* defines which outputs are to be changed
|
|
* @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
|
|
* defines the values the outputs specified by mask are to be set to
|
|
*/
|
|
static void gpio_chip_set_multiple(struct gpio_chip *chip,
|
|
unsigned long *mask, unsigned long *bits)
|
|
{
|
|
if (chip->set_multiple) {
|
|
chip->set_multiple(chip, mask, bits);
|
|
} else {
|
|
int i;
|
|
for (i = 0; i < chip->ngpio; i++) {
|
|
if (mask[BIT_WORD(i)] == 0) {
|
|
/* no more set bits in this mask word;
|
|
* skip ahead to the next word */
|
|
i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
|
|
continue;
|
|
}
|
|
/* set outputs if the corresponding mask bit is set */
|
|
if (__test_and_clear_bit(i, mask))
|
|
chip->set(chip, i, test_bit(i, bits));
|
|
}
|
|
}
|
|
}
|
|
|
|
void gpiod_set_array_value_complex(bool raw, bool can_sleep,
|
|
unsigned int array_size,
|
|
struct gpio_desc **desc_array,
|
|
int *value_array)
|
|
{
|
|
int i = 0;
|
|
|
|
while (i < array_size) {
|
|
struct gpio_chip *chip = desc_array[i]->gdev->chip;
|
|
unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
|
|
unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
|
|
int count = 0;
|
|
|
|
if (!can_sleep)
|
|
WARN_ON(chip->can_sleep);
|
|
|
|
memset(mask, 0, sizeof(mask));
|
|
do {
|
|
struct gpio_desc *desc = desc_array[i];
|
|
int hwgpio = gpio_chip_hwgpio(desc);
|
|
int value = value_array[i];
|
|
|
|
if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
trace_gpio_value(desc_to_gpio(desc), 0, value);
|
|
/*
|
|
* collect all normal outputs belonging to the same chip
|
|
* open drain and open source outputs are set individually
|
|
*/
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
|
|
_gpio_set_open_drain_value(desc, value);
|
|
} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
|
|
_gpio_set_open_source_value(desc, value);
|
|
} else {
|
|
__set_bit(hwgpio, mask);
|
|
if (value)
|
|
__set_bit(hwgpio, bits);
|
|
else
|
|
__clear_bit(hwgpio, bits);
|
|
count++;
|
|
}
|
|
i++;
|
|
} while ((i < array_size) &&
|
|
(desc_array[i]->gdev->chip == chip));
|
|
/* push collected bits to outputs */
|
|
if (count != 0)
|
|
gpio_chip_set_multiple(chip, mask, bits);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gpiod_set_raw_value() - assign a gpio's raw value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the raw value of the GPIO, i.e. the value of its physical line without
|
|
* regard for its ACTIVE_LOW status.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
|
|
{
|
|
VALIDATE_DESC_VOID(desc);
|
|
/* Should be using gpiod_set_raw_value_cansleep() */
|
|
WARN_ON(desc->gdev->chip->can_sleep);
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
|
|
|
|
/**
|
|
* gpiod_set_value() - assign a gpio's value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_value(struct gpio_desc *desc, int value)
|
|
{
|
|
VALIDATE_DESC_VOID(desc);
|
|
/* Should be using gpiod_set_value_cansleep() */
|
|
WARN_ON(desc->gdev->chip->can_sleep);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_value);
|
|
|
|
/**
|
|
* gpiod_set_raw_array_value() - assign values to an array of GPIOs
|
|
* @array_size: number of elements in the descriptor / value arrays
|
|
* @desc_array: array of GPIO descriptors whose values will be assigned
|
|
* @value_array: array of values to assign
|
|
*
|
|
* Set the raw values of the GPIOs, i.e. the values of the physical lines
|
|
* without regard for their ACTIVE_LOW status.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_raw_array_value(unsigned int array_size,
|
|
struct gpio_desc **desc_array, int *value_array)
|
|
{
|
|
if (!desc_array)
|
|
return;
|
|
gpiod_set_array_value_complex(true, false, array_size, desc_array,
|
|
value_array);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
|
|
|
|
/**
|
|
* gpiod_set_array_value() - assign values to an array of GPIOs
|
|
* @array_size: number of elements in the descriptor / value arrays
|
|
* @desc_array: array of GPIO descriptors whose values will be assigned
|
|
* @value_array: array of values to assign
|
|
*
|
|
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
|
|
* into account.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_array_value(unsigned int array_size,
|
|
struct gpio_desc **desc_array, int *value_array)
|
|
{
|
|
if (!desc_array)
|
|
return;
|
|
gpiod_set_array_value_complex(false, false, array_size, desc_array,
|
|
value_array);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_array_value);
|
|
|
|
/**
|
|
* gpiod_cansleep() - report whether gpio value access may sleep
|
|
* @desc: gpio to check
|
|
*
|
|
*/
|
|
int gpiod_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
VALIDATE_DESC(desc);
|
|
return desc->gdev->chip->can_sleep;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_cansleep);
|
|
|
|
/**
|
|
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
|
|
* @desc: gpio whose IRQ will be returned (already requested)
|
|
*
|
|
* Return the IRQ corresponding to the passed GPIO, or an error code in case of
|
|
* error.
|
|
*/
|
|
int gpiod_to_irq(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
int offset;
|
|
|
|
/*
|
|
* Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
|
|
* requires this function to not return zero on an invalid descriptor
|
|
* but rather a negative error number.
|
|
*/
|
|
if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
|
|
return -EINVAL;
|
|
|
|
chip = desc->gdev->chip;
|
|
offset = gpio_chip_hwgpio(desc);
|
|
if (chip->to_irq) {
|
|
int retirq = chip->to_irq(chip, offset);
|
|
|
|
/* Zero means NO_IRQ */
|
|
if (!retirq)
|
|
return -ENXIO;
|
|
|
|
return retirq;
|
|
}
|
|
return -ENXIO;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_to_irq);
|
|
|
|
/**
|
|
* gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
|
|
* @chip: the chip the GPIO to lock belongs to
|
|
* @offset: the offset of the GPIO to lock as IRQ
|
|
*
|
|
* This is used directly by GPIO drivers that want to lock down
|
|
* a certain GPIO line to be used for IRQs.
|
|
*/
|
|
int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
struct gpio_desc *desc;
|
|
|
|
desc = gpiochip_get_desc(chip, offset);
|
|
if (IS_ERR(desc))
|
|
return PTR_ERR(desc);
|
|
|
|
/*
|
|
* If it's fast: flush the direction setting if something changed
|
|
* behind our back
|
|
*/
|
|
if (!chip->can_sleep && chip->get_direction) {
|
|
int dir = chip->get_direction(chip, offset);
|
|
|
|
if (dir)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
else
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
|
|
if (test_bit(FLAG_IS_OUT, &desc->flags)) {
|
|
chip_err(chip,
|
|
"%s: tried to flag a GPIO set as output for IRQ\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
|
|
|
|
/**
|
|
* gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
|
|
* @chip: the chip the GPIO to lock belongs to
|
|
* @offset: the offset of the GPIO to lock as IRQ
|
|
*
|
|
* This is used directly by GPIO drivers that want to indicate
|
|
* that a certain GPIO is no longer used exclusively for IRQ.
|
|
*/
|
|
void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
if (offset >= chip->ngpio)
|
|
return;
|
|
|
|
clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
|
|
|
|
bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
if (offset >= chip->ngpio)
|
|
return false;
|
|
|
|
return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
|
|
|
|
bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
if (offset >= chip->ngpio)
|
|
return false;
|
|
|
|
return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
|
|
|
|
bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
if (offset >= chip->ngpio)
|
|
return false;
|
|
|
|
return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
|
|
|
|
/**
|
|
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
|
|
* its ACTIVE_LOW status, or negative errno on failure.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
VALIDATE_DESC(desc);
|
|
return _gpiod_get_raw_value(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_get_value_cansleep() - return a gpio's value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
|
|
* account, or negative errno on failure.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
int value;
|
|
|
|
might_sleep_if(extra_checks);
|
|
VALIDATE_DESC(desc);
|
|
value = _gpiod_get_raw_value(desc);
|
|
if (value < 0)
|
|
return value;
|
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_raw_value_cansleep() - assign a gpio's raw value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the raw value of the GPIO, i.e. the value of its physical line without
|
|
* regard for its ACTIVE_LOW status.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
VALIDATE_DESC_VOID(desc);
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_value_cansleep() - assign a gpio's value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
VALIDATE_DESC_VOID(desc);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
|
|
* @array_size: number of elements in the descriptor / value arrays
|
|
* @desc_array: array of GPIO descriptors whose values will be assigned
|
|
* @value_array: array of values to assign
|
|
*
|
|
* Set the raw values of the GPIOs, i.e. the values of the physical lines
|
|
* without regard for their ACTIVE_LOW status.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
|
|
struct gpio_desc **desc_array,
|
|
int *value_array)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc_array)
|
|
return;
|
|
gpiod_set_array_value_complex(true, true, array_size, desc_array,
|
|
value_array);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
|
|
* @array_size: number of elements in the descriptor / value arrays
|
|
* @desc_array: array of GPIO descriptors whose values will be assigned
|
|
* @value_array: array of values to assign
|
|
*
|
|
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
|
|
* into account.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_array_value_cansleep(unsigned int array_size,
|
|
struct gpio_desc **desc_array,
|
|
int *value_array)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc_array)
|
|
return;
|
|
gpiod_set_array_value_complex(false, true, array_size, desc_array,
|
|
value_array);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_add_lookup_table() - register GPIO device consumers
|
|
* @table: table of consumers to register
|
|
*/
|
|
void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
|
|
{
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_add_tail(&table->list, &gpio_lookup_list);
|
|
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
}
|
|
|
|
/**
|
|
* gpiod_remove_lookup_table() - unregister GPIO device consumers
|
|
* @table: table of consumers to unregister
|
|
*/
|
|
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
|
|
{
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_del(&table->list);
|
|
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
}
|
|
|
|
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
|
|
{
|
|
const char *dev_id = dev ? dev_name(dev) : NULL;
|
|
struct gpiod_lookup_table *table;
|
|
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_for_each_entry(table, &gpio_lookup_list, list) {
|
|
if (table->dev_id && dev_id) {
|
|
/*
|
|
* Valid strings on both ends, must be identical to have
|
|
* a match
|
|
*/
|
|
if (!strcmp(table->dev_id, dev_id))
|
|
goto found;
|
|
} else {
|
|
/*
|
|
* One of the pointers is NULL, so both must be to have
|
|
* a match
|
|
*/
|
|
if (dev_id == table->dev_id)
|
|
goto found;
|
|
}
|
|
}
|
|
table = NULL;
|
|
|
|
found:
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
return table;
|
|
}
|
|
|
|
static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
struct gpio_desc *desc = ERR_PTR(-ENOENT);
|
|
struct gpiod_lookup_table *table;
|
|
struct gpiod_lookup *p;
|
|
|
|
table = gpiod_find_lookup_table(dev);
|
|
if (!table)
|
|
return desc;
|
|
|
|
for (p = &table->table[0]; p->chip_label; p++) {
|
|
struct gpio_chip *chip;
|
|
|
|
/* idx must always match exactly */
|
|
if (p->idx != idx)
|
|
continue;
|
|
|
|
/* If the lookup entry has a con_id, require exact match */
|
|
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
|
|
continue;
|
|
|
|
chip = find_chip_by_name(p->chip_label);
|
|
|
|
if (!chip) {
|
|
dev_err(dev, "cannot find GPIO chip %s\n",
|
|
p->chip_label);
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
if (chip->ngpio <= p->chip_hwnum) {
|
|
dev_err(dev,
|
|
"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
|
|
idx, p->chip_hwnum, chip->ngpio - 1,
|
|
chip->label);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
desc = gpiochip_get_desc(chip, p->chip_hwnum);
|
|
*flags = p->flags;
|
|
|
|
return desc;
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
|
|
static int dt_gpio_count(struct device *dev, const char *con_id)
|
|
{
|
|
int ret;
|
|
char propname[32];
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
|
|
if (con_id)
|
|
snprintf(propname, sizeof(propname), "%s-%s",
|
|
con_id, gpio_suffixes[i]);
|
|
else
|
|
snprintf(propname, sizeof(propname), "%s",
|
|
gpio_suffixes[i]);
|
|
|
|
ret = of_gpio_named_count(dev->of_node, propname);
|
|
if (ret >= 0)
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int platform_gpio_count(struct device *dev, const char *con_id)
|
|
{
|
|
struct gpiod_lookup_table *table;
|
|
struct gpiod_lookup *p;
|
|
unsigned int count = 0;
|
|
|
|
table = gpiod_find_lookup_table(dev);
|
|
if (!table)
|
|
return -ENOENT;
|
|
|
|
for (p = &table->table[0]; p->chip_label; p++) {
|
|
if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
|
|
(!con_id && !p->con_id))
|
|
count++;
|
|
}
|
|
if (!count)
|
|
return -ENOENT;
|
|
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* gpiod_count - return the number of GPIOs associated with a device / function
|
|
* or -ENOENT if no GPIO has been assigned to the requested function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
*/
|
|
int gpiod_count(struct device *dev, const char *con_id)
|
|
{
|
|
int count = -ENOENT;
|
|
|
|
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
|
|
count = dt_gpio_count(dev, con_id);
|
|
else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
|
|
count = acpi_gpio_count(dev, con_id);
|
|
|
|
if (count < 0)
|
|
count = platform_gpio_count(dev, con_id);
|
|
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_count);
|
|
|
|
/**
|
|
* gpiod_get - obtain a GPIO for a given GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @flags: optional GPIO initialization flags
|
|
*
|
|
* Return the GPIO descriptor corresponding to the function con_id of device
|
|
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
|
|
* another IS_ERR() code if an error occurred while trying to acquire the GPIO.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
|
|
enum gpiod_flags flags)
|
|
{
|
|
return gpiod_get_index(dev, con_id, 0, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get);
|
|
|
|
/**
|
|
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @flags: optional GPIO initialization flags
|
|
*
|
|
* This is equivalent to gpiod_get(), except that when no GPIO was assigned to
|
|
* the requested function it will return NULL. This is convenient for drivers
|
|
* that need to handle optional GPIOs.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
|
|
const char *con_id,
|
|
enum gpiod_flags flags)
|
|
{
|
|
return gpiod_get_index_optional(dev, con_id, 0, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_optional);
|
|
|
|
|
|
/**
|
|
* gpiod_configure_flags - helper function to configure a given GPIO
|
|
* @desc: gpio whose value will be assigned
|
|
* @con_id: function within the GPIO consumer
|
|
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
|
|
* of_get_gpio_hog()
|
|
* @dflags: gpiod_flags - optional GPIO initialization flags
|
|
*
|
|
* Return 0 on success, -ENOENT if no GPIO has been assigned to the
|
|
* requested function and/or index, or another IS_ERR() code if an error
|
|
* occurred while trying to acquire the GPIO.
|
|
*/
|
|
static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
|
|
unsigned long lflags, enum gpiod_flags dflags)
|
|
{
|
|
int status;
|
|
|
|
if (lflags & GPIO_ACTIVE_LOW)
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
if (lflags & GPIO_OPEN_DRAIN)
|
|
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
if (lflags & GPIO_OPEN_SOURCE)
|
|
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
|
|
/* No particular flag request, return here... */
|
|
if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
|
|
pr_debug("no flags found for %s\n", con_id);
|
|
return 0;
|
|
}
|
|
|
|
/* Process flags */
|
|
if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
|
|
status = gpiod_direction_output(desc,
|
|
dflags & GPIOD_FLAGS_BIT_DIR_VAL);
|
|
else
|
|
status = gpiod_direction_input(desc);
|
|
|
|
return status;
|
|
}
|
|
|
|
/**
|
|
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @idx: index of the GPIO to obtain in the consumer
|
|
* @flags: optional GPIO initialization flags
|
|
*
|
|
* This variant of gpiod_get() allows to access GPIOs other than the first
|
|
* defined one for functions that define several GPIOs.
|
|
*
|
|
* Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
|
|
* requested function and/or index, or another IS_ERR() code if an error
|
|
* occurred while trying to acquire the GPIO.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
|
|
const char *con_id,
|
|
unsigned int idx,
|
|
enum gpiod_flags flags)
|
|
{
|
|
struct gpio_desc *desc = NULL;
|
|
int status;
|
|
enum gpio_lookup_flags lookupflags = 0;
|
|
/* Maybe we have a device name, maybe not */
|
|
const char *devname = dev ? dev_name(dev) : "?";
|
|
|
|
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
|
|
|
|
if (dev) {
|
|
/* Using device tree? */
|
|
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
|
|
dev_dbg(dev, "using device tree for GPIO lookup\n");
|
|
desc = of_find_gpio(dev, con_id, idx, &lookupflags);
|
|
} else if (ACPI_COMPANION(dev)) {
|
|
dev_dbg(dev, "using ACPI for GPIO lookup\n");
|
|
desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Either we are not using DT or ACPI, or their lookup did not return
|
|
* a result. In that case, use platform lookup as a fallback.
|
|
*/
|
|
if (!desc || desc == ERR_PTR(-ENOENT)) {
|
|
dev_dbg(dev, "using lookup tables for GPIO lookup\n");
|
|
desc = gpiod_find(dev, con_id, idx, &lookupflags);
|
|
}
|
|
|
|
if (IS_ERR(desc)) {
|
|
dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
|
|
return desc;
|
|
}
|
|
|
|
/*
|
|
* If a connection label was passed use that, else attempt to use
|
|
* the device name as label
|
|
*/
|
|
status = gpiod_request(desc, con_id ? con_id : devname);
|
|
if (status < 0)
|
|
return ERR_PTR(status);
|
|
|
|
status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
|
|
if (status < 0) {
|
|
dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
|
|
gpiod_put(desc);
|
|
return ERR_PTR(status);
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_index);
|
|
|
|
/**
|
|
* fwnode_get_named_gpiod - obtain a GPIO from firmware node
|
|
* @fwnode: handle of the firmware node
|
|
* @propname: name of the firmware property representing the GPIO
|
|
*
|
|
* This function can be used for drivers that get their configuration
|
|
* from firmware.
|
|
*
|
|
* Function properly finds the corresponding GPIO using whatever is the
|
|
* underlying firmware interface and then makes sure that the GPIO
|
|
* descriptor is requested before it is returned to the caller.
|
|
*
|
|
* In case of error an ERR_PTR() is returned.
|
|
*/
|
|
struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
|
|
const char *propname)
|
|
{
|
|
struct gpio_desc *desc = ERR_PTR(-ENODEV);
|
|
bool active_low = false;
|
|
bool single_ended = false;
|
|
bool open_drain = false;
|
|
int ret;
|
|
|
|
if (!fwnode)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (is_of_node(fwnode)) {
|
|
enum of_gpio_flags flags;
|
|
|
|
desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
|
|
&flags);
|
|
if (!IS_ERR(desc)) {
|
|
active_low = flags & OF_GPIO_ACTIVE_LOW;
|
|
single_ended = flags & OF_GPIO_SINGLE_ENDED;
|
|
open_drain = flags & OF_GPIO_OPEN_DRAIN;
|
|
}
|
|
} else if (is_acpi_node(fwnode)) {
|
|
struct acpi_gpio_info info;
|
|
|
|
desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
|
|
if (!IS_ERR(desc))
|
|
active_low = info.polarity == GPIO_ACTIVE_LOW;
|
|
}
|
|
|
|
if (IS_ERR(desc))
|
|
return desc;
|
|
|
|
ret = gpiod_request(desc, NULL);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
|
|
if (active_low)
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
|
|
if (single_ended) {
|
|
if (open_drain)
|
|
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
else
|
|
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
|
|
|
|
/**
|
|
* gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
|
|
* function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @index: index of the GPIO to obtain in the consumer
|
|
* @flags: optional GPIO initialization flags
|
|
*
|
|
* This is equivalent to gpiod_get_index(), except that when no GPIO with the
|
|
* specified index was assigned to the requested function it will return NULL.
|
|
* This is convenient for drivers that need to handle optional GPIOs.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
|
|
const char *con_id,
|
|
unsigned int index,
|
|
enum gpiod_flags flags)
|
|
{
|
|
struct gpio_desc *desc;
|
|
|
|
desc = gpiod_get_index(dev, con_id, index, flags);
|
|
if (IS_ERR(desc)) {
|
|
if (PTR_ERR(desc) == -ENOENT)
|
|
return NULL;
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
|
|
|
|
/**
|
|
* gpiod_hog - Hog the specified GPIO desc given the provided flags
|
|
* @desc: gpio whose value will be assigned
|
|
* @name: gpio line name
|
|
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
|
|
* of_get_gpio_hog()
|
|
* @dflags: gpiod_flags - optional GPIO initialization flags
|
|
*/
|
|
int gpiod_hog(struct gpio_desc *desc, const char *name,
|
|
unsigned long lflags, enum gpiod_flags dflags)
|
|
{
|
|
struct gpio_chip *chip;
|
|
struct gpio_desc *local_desc;
|
|
int hwnum;
|
|
int status;
|
|
|
|
chip = gpiod_to_chip(desc);
|
|
hwnum = gpio_chip_hwgpio(desc);
|
|
|
|
local_desc = gpiochip_request_own_desc(chip, hwnum, name);
|
|
if (IS_ERR(local_desc)) {
|
|
status = PTR_ERR(local_desc);
|
|
pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
|
|
name, chip->label, hwnum, status);
|
|
return status;
|
|
}
|
|
|
|
status = gpiod_configure_flags(desc, name, lflags, dflags);
|
|
if (status < 0) {
|
|
pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
|
|
name, chip->label, hwnum, status);
|
|
gpiochip_free_own_desc(desc);
|
|
return status;
|
|
}
|
|
|
|
/* Mark GPIO as hogged so it can be identified and removed later */
|
|
set_bit(FLAG_IS_HOGGED, &desc->flags);
|
|
|
|
pr_info("GPIO line %d (%s) hogged as %s%s\n",
|
|
desc_to_gpio(desc), name,
|
|
(dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
|
|
(dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
|
|
(dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
|
|
* @chip: gpio chip to act on
|
|
*
|
|
* This is only used by of_gpiochip_remove to free hogged gpios
|
|
*/
|
|
static void gpiochip_free_hogs(struct gpio_chip *chip)
|
|
{
|
|
int id;
|
|
|
|
for (id = 0; id < chip->ngpio; id++) {
|
|
if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
|
|
gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @flags: optional GPIO initialization flags
|
|
*
|
|
* This function acquires all the GPIOs defined under a given function.
|
|
*
|
|
* Return a struct gpio_descs containing an array of descriptors, -ENOENT if
|
|
* no GPIO has been assigned to the requested function, or another IS_ERR()
|
|
* code if an error occurred while trying to acquire the GPIOs.
|
|
*/
|
|
struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
|
|
const char *con_id,
|
|
enum gpiod_flags flags)
|
|
{
|
|
struct gpio_desc *desc;
|
|
struct gpio_descs *descs;
|
|
int count;
|
|
|
|
count = gpiod_count(dev, con_id);
|
|
if (count < 0)
|
|
return ERR_PTR(count);
|
|
|
|
descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
|
|
GFP_KERNEL);
|
|
if (!descs)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
for (descs->ndescs = 0; descs->ndescs < count; ) {
|
|
desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
|
|
if (IS_ERR(desc)) {
|
|
gpiod_put_array(descs);
|
|
return ERR_CAST(desc);
|
|
}
|
|
descs->desc[descs->ndescs] = desc;
|
|
descs->ndescs++;
|
|
}
|
|
return descs;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_array);
|
|
|
|
/**
|
|
* gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
|
|
* function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @flags: optional GPIO initialization flags
|
|
*
|
|
* This is equivalent to gpiod_get_array(), except that when no GPIO was
|
|
* assigned to the requested function it will return NULL.
|
|
*/
|
|
struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
|
|
const char *con_id,
|
|
enum gpiod_flags flags)
|
|
{
|
|
struct gpio_descs *descs;
|
|
|
|
descs = gpiod_get_array(dev, con_id, flags);
|
|
if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
|
|
return NULL;
|
|
|
|
return descs;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
|
|
|
|
/**
|
|
* gpiod_put - dispose of a GPIO descriptor
|
|
* @desc: GPIO descriptor to dispose of
|
|
*
|
|
* No descriptor can be used after gpiod_put() has been called on it.
|
|
*/
|
|
void gpiod_put(struct gpio_desc *desc)
|
|
{
|
|
gpiod_free(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_put);
|
|
|
|
/**
|
|
* gpiod_put_array - dispose of multiple GPIO descriptors
|
|
* @descs: struct gpio_descs containing an array of descriptors
|
|
*/
|
|
void gpiod_put_array(struct gpio_descs *descs)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < descs->ndescs; i++)
|
|
gpiod_put(descs->desc[i]);
|
|
|
|
kfree(descs);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_put_array);
|
|
|
|
static int __init gpiolib_dev_init(void)
|
|
{
|
|
int ret;
|
|
|
|
/* Register GPIO sysfs bus */
|
|
ret = bus_register(&gpio_bus_type);
|
|
if (ret < 0) {
|
|
pr_err("gpiolib: could not register GPIO bus type\n");
|
|
return ret;
|
|
}
|
|
|
|
ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
|
|
if (ret < 0) {
|
|
pr_err("gpiolib: failed to allocate char dev region\n");
|
|
bus_unregister(&gpio_bus_type);
|
|
} else {
|
|
gpiolib_initialized = true;
|
|
gpiochip_setup_devs();
|
|
}
|
|
return ret;
|
|
}
|
|
core_initcall(gpiolib_dev_init);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
|
|
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
|
|
{
|
|
unsigned i;
|
|
struct gpio_chip *chip = gdev->chip;
|
|
unsigned gpio = gdev->base;
|
|
struct gpio_desc *gdesc = &gdev->descs[0];
|
|
int is_out;
|
|
int is_irq;
|
|
|
|
for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
|
|
if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
|
|
if (gdesc->name) {
|
|
seq_printf(s, " gpio-%-3d (%-20.20s)\n",
|
|
gpio, gdesc->name);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
gpiod_get_direction(gdesc);
|
|
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
|
|
is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
|
|
seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
|
|
gpio, gdesc->name ? gdesc->name : "", gdesc->label,
|
|
is_out ? "out" : "in ",
|
|
chip->get
|
|
? (chip->get(chip, i) ? "hi" : "lo")
|
|
: "? ",
|
|
is_irq ? "IRQ" : " ");
|
|
seq_printf(s, "\n");
|
|
}
|
|
}
|
|
|
|
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_device *gdev = NULL;
|
|
loff_t index = *pos;
|
|
|
|
s->private = "";
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_for_each_entry(gdev, &gpio_devices, list)
|
|
if (index-- == 0) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return gdev;
|
|
}
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_device *gdev = v;
|
|
void *ret = NULL;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
if (list_is_last(&gdev->list, &gpio_devices))
|
|
ret = NULL;
|
|
else
|
|
ret = list_entry(gdev->list.next, struct gpio_device, list);
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
s->private = "\n";
|
|
++*pos;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void gpiolib_seq_stop(struct seq_file *s, void *v)
|
|
{
|
|
}
|
|
|
|
static int gpiolib_seq_show(struct seq_file *s, void *v)
|
|
{
|
|
struct gpio_device *gdev = v;
|
|
struct gpio_chip *chip = gdev->chip;
|
|
struct device *parent;
|
|
|
|
if (!chip) {
|
|
seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
|
|
dev_name(&gdev->dev));
|
|
return 0;
|
|
}
|
|
|
|
seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
|
|
dev_name(&gdev->dev),
|
|
gdev->base, gdev->base + gdev->ngpio - 1);
|
|
parent = chip->parent;
|
|
if (parent)
|
|
seq_printf(s, ", parent: %s/%s",
|
|
parent->bus ? parent->bus->name : "no-bus",
|
|
dev_name(parent));
|
|
if (chip->label)
|
|
seq_printf(s, ", %s", chip->label);
|
|
if (chip->can_sleep)
|
|
seq_printf(s, ", can sleep");
|
|
seq_printf(s, ":\n");
|
|
|
|
if (chip->dbg_show)
|
|
chip->dbg_show(s, chip);
|
|
else
|
|
gpiolib_dbg_show(s, gdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations gpiolib_seq_ops = {
|
|
.start = gpiolib_seq_start,
|
|
.next = gpiolib_seq_next,
|
|
.stop = gpiolib_seq_stop,
|
|
.show = gpiolib_seq_show,
|
|
};
|
|
|
|
static int gpiolib_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &gpiolib_seq_ops);
|
|
}
|
|
|
|
static const struct file_operations gpiolib_operations = {
|
|
.owner = THIS_MODULE,
|
|
.open = gpiolib_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static int __init gpiolib_debugfs_init(void)
|
|
{
|
|
/* /sys/kernel/debug/gpio */
|
|
(void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
|
|
NULL, NULL, &gpiolib_operations);
|
|
return 0;
|
|
}
|
|
subsys_initcall(gpiolib_debugfs_init);
|
|
|
|
#endif /* DEBUG_FS */
|