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tegrakernel/kernel/kernel-4.9/drivers/iio/pressure/zpa2326.c

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/*
* Murata ZPA2326 pressure and temperature sensor IIO driver
*
* Copyright (c) 2016 Parrot S.A.
*
* Author: Gregor Boirie <gregor.boirie@parrot.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
/**
* DOC: ZPA2326 theory of operations
*
* This driver supports %INDIO_DIRECT_MODE and %INDIO_BUFFER_TRIGGERED IIO
* modes.
* A internal hardware trigger is also implemented to dispatch registered IIO
* trigger consumers upon "sample ready" interrupts.
*
* ZPA2326 hardware supports 2 sampling mode: one shot and continuous.
*
* A complete one shot sampling cycle gets device out of low power mode,
* performs pressure and temperature measurements, then automatically switches
* back to low power mode. It is meant for on demand sampling with optimal power
* saving at the cost of lower sampling rate and higher software overhead.
* This is a natural candidate for IIO read_raw hook implementation
* (%INDIO_DIRECT_MODE). It is also used for triggered buffering support to
* ensure explicit synchronization with external trigger events
* (%INDIO_BUFFER_TRIGGERED).
*
* The continuous mode works according to a periodic hardware measurement
* process continuously pushing samples into an internal hardware FIFO (for
* pressure samples only). Measurement cycle completion may be signaled by a
* "sample ready" interrupt.
* Typical software sequence of operations :
* - get device out of low power mode,
* - setup hardware sampling period,
* - at end of period, upon data ready interrupt: pop pressure samples out of
* hardware FIFO and fetch temperature sample
* - when no longer needed, stop sampling process by putting device into
* low power mode.
* This mode is used to implement %INDIO_BUFFER_TRIGGERED mode if device tree
* declares a valid interrupt line. In this case, the internal hardware trigger
* drives acquisition.
*
* Note that hardware sampling frequency is taken into account only when
* internal hardware trigger is attached as the highest sampling rate seems to
* be the most energy efficient.
*
* TODO:
* preset pressure threshold crossing / IIO events ;
* differential pressure sampling ;
* hardware samples averaging.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include "zpa2326.h"
/* 200 ms should be enough for the longest conversion time in one-shot mode. */
#define ZPA2326_CONVERSION_JIFFIES (HZ / 5)
/* There should be a 1 ms delay (Tpup) after getting out of reset. */
#define ZPA2326_TPUP_USEC_MIN (1000)
#define ZPA2326_TPUP_USEC_MAX (2000)
/**
* struct zpa2326_frequency - Hardware sampling frequency descriptor
* @hz : Frequency in Hertz.
* @odr: Output Data Rate word as expected by %ZPA2326_CTRL_REG3_REG.
*/
struct zpa2326_frequency {
int hz;
u16 odr;
};
/*
* Keep these in strict ascending order: last array entry is expected to
* correspond to the highest sampling frequency.
*/
static const struct zpa2326_frequency zpa2326_sampling_frequencies[] = {
{ .hz = 1, .odr = 1 << ZPA2326_CTRL_REG3_ODR_SHIFT },
{ .hz = 5, .odr = 5 << ZPA2326_CTRL_REG3_ODR_SHIFT },
{ .hz = 11, .odr = 6 << ZPA2326_CTRL_REG3_ODR_SHIFT },
{ .hz = 23, .odr = 7 << ZPA2326_CTRL_REG3_ODR_SHIFT },
};
/* Return the highest hardware sampling frequency available. */
static const struct zpa2326_frequency *zpa2326_highest_frequency(void)
{
return &zpa2326_sampling_frequencies[
ARRAY_SIZE(zpa2326_sampling_frequencies) - 1];
}
/**
* struct zpa_private - Per-device internal private state
* @timestamp: Buffered samples ready datum.
* @regmap: Underlying I2C / SPI bus adapter used to abstract slave register
* accesses.
* @result: Allows sampling logic to get completion status of operations
* that interrupt handlers perform asynchronously.
* @data_ready: Interrupt handler uses this to wake user context up at sampling
* operation completion.
* @trigger: Optional hardware / interrupt driven trigger used to notify
* external devices a new sample is ready.
* @waken: Flag indicating whether or not device has just been powered on.
* @irq: Optional interrupt line: negative or zero if not declared into
* DT, in which case sampling logic keeps polling status register
* to detect completion.
* @frequency: Current hardware sampling frequency.
* @vref: Power / voltage reference.
* @vdd: Power supply.
*/
struct zpa2326_private {
s64 timestamp;
struct regmap *regmap;
int result;
struct completion data_ready;
struct iio_trigger *trigger;
bool waken;
int irq;
const struct zpa2326_frequency *frequency;
struct regulator *vref;
struct regulator *vdd;
};
#define zpa2326_err(_idev, _format, _arg...) \
dev_err(_idev->dev.parent, _format, ##_arg)
#define zpa2326_warn(_idev, _format, _arg...) \
dev_warn(_idev->dev.parent, _format, ##_arg)
#ifdef DEBUG
#define zpa2326_dbg(_idev, _format, _arg...) \
dev_dbg(_idev->dev.parent, _format, ##_arg)
#else
#define zpa2326_dbg(_idev, _format, _arg...)
#endif
bool zpa2326_isreg_writeable(struct device *dev, unsigned int reg)
{
switch (reg) {
case ZPA2326_REF_P_XL_REG:
case ZPA2326_REF_P_L_REG:
case ZPA2326_REF_P_H_REG:
case ZPA2326_RES_CONF_REG:
case ZPA2326_CTRL_REG0_REG:
case ZPA2326_CTRL_REG1_REG:
case ZPA2326_CTRL_REG2_REG:
case ZPA2326_CTRL_REG3_REG:
case ZPA2326_THS_P_LOW_REG:
case ZPA2326_THS_P_HIGH_REG:
return true;
default:
return false;
}
}
EXPORT_SYMBOL_GPL(zpa2326_isreg_writeable);
bool zpa2326_isreg_readable(struct device *dev, unsigned int reg)
{
switch (reg) {
case ZPA2326_REF_P_XL_REG:
case ZPA2326_REF_P_L_REG:
case ZPA2326_REF_P_H_REG:
case ZPA2326_DEVICE_ID_REG:
case ZPA2326_RES_CONF_REG:
case ZPA2326_CTRL_REG0_REG:
case ZPA2326_CTRL_REG1_REG:
case ZPA2326_CTRL_REG2_REG:
case ZPA2326_CTRL_REG3_REG:
case ZPA2326_INT_SOURCE_REG:
case ZPA2326_THS_P_LOW_REG:
case ZPA2326_THS_P_HIGH_REG:
case ZPA2326_STATUS_REG:
case ZPA2326_PRESS_OUT_XL_REG:
case ZPA2326_PRESS_OUT_L_REG:
case ZPA2326_PRESS_OUT_H_REG:
case ZPA2326_TEMP_OUT_L_REG:
case ZPA2326_TEMP_OUT_H_REG:
return true;
default:
return false;
}
}
EXPORT_SYMBOL_GPL(zpa2326_isreg_readable);
bool zpa2326_isreg_precious(struct device *dev, unsigned int reg)
{
switch (reg) {
case ZPA2326_INT_SOURCE_REG:
case ZPA2326_PRESS_OUT_H_REG:
return true;
default:
return false;
}
}
EXPORT_SYMBOL_GPL(zpa2326_isreg_precious);
/**
* zpa2326_enable_device() - Enable device, i.e. get out of low power mode.
* @indio_dev: The IIO device associated with the hardware to enable.
*
* Required to access complete register space and to perform any sampling
* or control operations.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_enable_device(const struct iio_dev *indio_dev)
{
int err;
err = regmap_write(((struct zpa2326_private *)
iio_priv(indio_dev))->regmap,
ZPA2326_CTRL_REG0_REG, ZPA2326_CTRL_REG0_ENABLE);
if (err) {
zpa2326_err(indio_dev, "failed to enable device (%d)", err);
return err;
}
zpa2326_dbg(indio_dev, "enabled");
return 0;
}
/**
* zpa2326_sleep() - Disable device, i.e. switch to low power mode.
* @indio_dev: The IIO device associated with the hardware to disable.
*
* Only %ZPA2326_DEVICE_ID_REG and %ZPA2326_CTRL_REG0_REG registers may be
* accessed once device is in the disabled state.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_sleep(const struct iio_dev *indio_dev)
{
int err;
err = regmap_write(((struct zpa2326_private *)
iio_priv(indio_dev))->regmap,
ZPA2326_CTRL_REG0_REG, 0);
if (err) {
zpa2326_err(indio_dev, "failed to sleep (%d)", err);
return err;
}
zpa2326_dbg(indio_dev, "sleeping");
return 0;
}
/**
* zpa2326_reset_device() - Reset device to default hardware state.
* @indio_dev: The IIO device associated with the hardware to reset.
*
* Disable sampling and empty hardware FIFO.
* Device must be enabled before reset, i.e. not in low power mode.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_reset_device(const struct iio_dev *indio_dev)
{
int err;
err = regmap_write(((struct zpa2326_private *)
iio_priv(indio_dev))->regmap,
ZPA2326_CTRL_REG2_REG, ZPA2326_CTRL_REG2_SWRESET);
if (err) {
zpa2326_err(indio_dev, "failed to reset device (%d)", err);
return err;
}
usleep_range(ZPA2326_TPUP_USEC_MIN, ZPA2326_TPUP_USEC_MAX);
zpa2326_dbg(indio_dev, "reset");
return 0;
}
/**
* zpa2326_start_oneshot() - Start a single sampling cycle, i.e. in one shot
* mode.
* @indio_dev: The IIO device associated with the sampling hardware.
*
* Device must have been previously enabled and configured for one shot mode.
* Device will be switched back to low power mode at end of cycle.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_start_oneshot(const struct iio_dev *indio_dev)
{
int err;
err = regmap_write(((struct zpa2326_private *)
iio_priv(indio_dev))->regmap,
ZPA2326_CTRL_REG0_REG,
ZPA2326_CTRL_REG0_ENABLE |
ZPA2326_CTRL_REG0_ONE_SHOT);
if (err) {
zpa2326_err(indio_dev, "failed to start one shot cycle (%d)",
err);
return err;
}
zpa2326_dbg(indio_dev, "one shot cycle started");
return 0;
}
/**
* zpa2326_power_on() - Power on device to allow subsequent configuration.
* @indio_dev: The IIO device associated with the sampling hardware.
* @private: Internal private state related to @indio_dev.
*
* Sampling will be disabled, preventing strange things from happening in our
* back. Hardware FIFO content will be cleared.
* When successful, device will be left in the enabled state to allow further
* configuration.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_power_on(const struct iio_dev *indio_dev,
const struct zpa2326_private *private)
{
int err;
err = regulator_enable(private->vref);
if (err)
return err;
err = regulator_enable(private->vdd);
if (err)
goto vref;
zpa2326_dbg(indio_dev, "powered on");
err = zpa2326_enable_device(indio_dev);
if (err)
goto vdd;
err = zpa2326_reset_device(indio_dev);
if (err)
goto sleep;
return 0;
sleep:
zpa2326_sleep(indio_dev);
vdd:
regulator_disable(private->vdd);
vref:
regulator_disable(private->vref);
zpa2326_dbg(indio_dev, "powered off");
return err;
}
/**
* zpa2326_power_off() - Power off device, i.e. disable attached power
* regulators.
* @indio_dev: The IIO device associated with the sampling hardware.
* @private: Internal private state related to @indio_dev.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static void zpa2326_power_off(const struct iio_dev *indio_dev,
const struct zpa2326_private *private)
{
regulator_disable(private->vdd);
regulator_disable(private->vref);
zpa2326_dbg(indio_dev, "powered off");
}
/**
* zpa2326_config_oneshot() - Setup device for one shot / on demand mode.
* @indio_dev: The IIO device associated with the sampling hardware.
* @irq: Optional interrupt line the hardware uses to notify new data
* samples are ready. Negative or zero values indicate no interrupts
* are available, meaning polling is required.
*
* Output Data Rate is configured for the highest possible rate so that
* conversion time and power consumption are reduced to a minimum.
* Note that hardware internal averaging machinery (not implemented in this
* driver) is not applicable in this mode.
*
* Device must have been previously enabled before calling
* zpa2326_config_oneshot().
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_config_oneshot(const struct iio_dev *indio_dev,
int irq)
{
struct regmap *regs = ((struct zpa2326_private *)
iio_priv(indio_dev))->regmap;
const struct zpa2326_frequency *freq = zpa2326_highest_frequency();
int err;
/* Setup highest available Output Data Rate for one shot mode. */
err = regmap_write(regs, ZPA2326_CTRL_REG3_REG, freq->odr);
if (err)
return err;
if (irq > 0) {
/* Request interrupt when new sample is available. */
err = regmap_write(regs, ZPA2326_CTRL_REG1_REG,
(u8)~ZPA2326_CTRL_REG1_MASK_DATA_READY);
if (err) {
dev_err(indio_dev->dev.parent,
"failed to setup one shot mode (%d)", err);
return err;
}
}
zpa2326_dbg(indio_dev, "one shot mode setup @%dHz", freq->hz);
return 0;
}
/**
* zpa2326_clear_fifo() - Clear remaining entries in hardware FIFO.
* @indio_dev: The IIO device associated with the sampling hardware.
* @min_count: Number of samples present within hardware FIFO.
*
* @min_count argument is a hint corresponding to the known minimum number of
* samples currently living in the FIFO. This allows to reduce the number of bus
* accesses by skipping status register read operation as long as we know for
* sure there are still entries left.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_clear_fifo(const struct iio_dev *indio_dev,
unsigned int min_count)
{
struct regmap *regs = ((struct zpa2326_private *)
iio_priv(indio_dev))->regmap;
int err;
unsigned int val;
if (!min_count) {
/*
* No hint: read status register to determine whether FIFO is
* empty or not.
*/
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
if (err < 0)
goto err;
if (val & ZPA2326_STATUS_FIFO_E)
/* Fifo is empty: nothing to trash. */
return 0;
}
/* Clear FIFO. */
do {
/*
* A single fetch from pressure MSB register is enough to pop
* values out of FIFO.
*/
err = regmap_read(regs, ZPA2326_PRESS_OUT_H_REG, &val);
if (err < 0)
goto err;
if (min_count) {
/*
* We know for sure there are at least min_count entries
* left in FIFO. Skip status register read.
*/
min_count--;
continue;
}
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
if (err < 0)
goto err;
} while (!(val & ZPA2326_STATUS_FIFO_E));
zpa2326_dbg(indio_dev, "FIFO cleared");
return 0;
err:
zpa2326_err(indio_dev, "failed to clear FIFO (%d)", err);
return err;
}
/**
* zpa2326_dequeue_pressure() - Retrieve the most recent pressure sample from
* hardware FIFO.
* @indio_dev: The IIO device associated with the sampling hardware.
* @pressure: Sampled pressure output.
*
* Note that ZPA2326 hardware FIFO stores pressure samples only.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_dequeue_pressure(const struct iio_dev *indio_dev,
u32 *pressure)
{
struct regmap *regs = ((struct zpa2326_private *)
iio_priv(indio_dev))->regmap;
unsigned int val;
int err;
int cleared = -1;
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
if (err < 0)
return err;
*pressure = 0;
if (val & ZPA2326_STATUS_P_OR) {
/*
* Fifo overrun : first sample dequeued from FIFO is the
* newest.
*/
zpa2326_warn(indio_dev, "FIFO overflow");
err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure,
3);
if (err)
return err;
#define ZPA2326_FIFO_DEPTH (16U)
/* Hardware FIFO may hold no more than 16 pressure samples. */
return zpa2326_clear_fifo(indio_dev, ZPA2326_FIFO_DEPTH - 1);
}
/*
* Fifo has not overflown : retrieve newest sample. We need to pop
* values out until FIFO is empty : last fetched pressure is the newest.
* In nominal cases, we should find a single queued sample only.
*/
do {
err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure,
3);
if (err)
return err;
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
if (err < 0)
return err;
cleared++;
} while (!(val & ZPA2326_STATUS_FIFO_E));
if (cleared)
/*
* Samples were pushed by hardware during previous rounds but we
* didn't consume them fast enough: inform user.
*/
zpa2326_dbg(indio_dev, "cleared %d FIFO entries", cleared);
return 0;
}
/**
* zpa2326_fill_sample_buffer() - Enqueue new channel samples to IIO buffer.
* @indio_dev: The IIO device associated with the sampling hardware.
* @private: Internal private state related to @indio_dev.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_fill_sample_buffer(struct iio_dev *indio_dev,
const struct zpa2326_private *private)
{
struct {
u32 pressure;
u16 temperature;
u64 timestamp;
} sample;
int err;
if (test_bit(0, indio_dev->active_scan_mask)) {
/* Get current pressure from hardware FIFO. */
err = zpa2326_dequeue_pressure(indio_dev, &sample.pressure);
if (err) {
zpa2326_warn(indio_dev, "failed to fetch pressure (%d)",
err);
return err;
}
}
if (test_bit(1, indio_dev->active_scan_mask)) {
/* Get current temperature. */
err = regmap_bulk_read(private->regmap, ZPA2326_TEMP_OUT_L_REG,
&sample.temperature, 2);
if (err) {
zpa2326_warn(indio_dev,
"failed to fetch temperature (%d)", err);
return err;
}
}
/*
* Now push samples using timestamp stored either :
* - by hardware interrupt handler if interrupt is available: see
* zpa2326_handle_irq(),
* - or oneshot completion polling machinery : see
* zpa2326_trigger_handler().
*/
zpa2326_dbg(indio_dev, "filling raw samples buffer");
iio_push_to_buffers_with_timestamp(indio_dev, &sample,
private->timestamp);
return 0;
}
#ifdef CONFIG_PM
static int zpa2326_runtime_suspend(struct device *parent)
{
const struct iio_dev *indio_dev = dev_get_drvdata(parent);
if (pm_runtime_autosuspend_expiration(parent))
/* Userspace changed autosuspend delay. */
return -EAGAIN;
zpa2326_power_off(indio_dev, iio_priv(indio_dev));
return 0;
}
static int zpa2326_runtime_resume(struct device *parent)
{
const struct iio_dev *indio_dev = dev_get_drvdata(parent);
return zpa2326_power_on(indio_dev, iio_priv(indio_dev));
}
const struct dev_pm_ops zpa2326_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(zpa2326_runtime_suspend, zpa2326_runtime_resume,
NULL)
};
EXPORT_SYMBOL_GPL(zpa2326_pm_ops);
/**
* zpa2326_resume() - Request the PM layer to power supply the device.
* @indio_dev: The IIO device associated with the sampling hardware.
*
* Return:
* < 0 - a negative error code meaning failure ;
* 0 - success, device has just been powered up ;
* 1 - success, device was already powered.
*/
static int zpa2326_resume(const struct iio_dev *indio_dev)
{
int err;
err = pm_runtime_get_sync(indio_dev->dev.parent);
if (err < 0) {
pm_runtime_put(indio_dev->dev.parent);
return err;
}
if (err > 0) {
/*
* Device was already power supplied: get it out of low power
* mode and inform caller.
*/
zpa2326_enable_device(indio_dev);
return 1;
}
/* Inform caller device has just been brought back to life. */
return 0;
}
/**
* zpa2326_suspend() - Schedule a power down using autosuspend feature of PM
* layer.
* @indio_dev: The IIO device associated with the sampling hardware.
*
* Device is switched to low power mode at first to save power even when
* attached regulator is a "dummy" one.
*/
static void zpa2326_suspend(struct iio_dev *indio_dev)
{
struct device *parent = indio_dev->dev.parent;
zpa2326_sleep(indio_dev);
pm_runtime_mark_last_busy(parent);
pm_runtime_put_autosuspend(parent);
}
static void zpa2326_init_runtime(struct device *parent)
{
pm_runtime_get_noresume(parent);
pm_runtime_set_active(parent);
pm_runtime_enable(parent);
pm_runtime_set_autosuspend_delay(parent, 1000);
pm_runtime_use_autosuspend(parent);
pm_runtime_mark_last_busy(parent);
pm_runtime_put_autosuspend(parent);
}
static void zpa2326_fini_runtime(struct device *parent)
{
pm_runtime_disable(parent);
pm_runtime_set_suspended(parent);
}
#else /* !CONFIG_PM */
static int zpa2326_resume(const struct iio_dev *indio_dev)
{
zpa2326_enable_device(indio_dev);
return 0;
}
static void zpa2326_suspend(struct iio_dev *indio_dev)
{
zpa2326_sleep(indio_dev);
}
#define zpa2326_init_runtime(_parent)
#define zpa2326_fini_runtime(_parent)
#endif /* !CONFIG_PM */
/**
* zpa2326_handle_irq() - Process hardware interrupts.
* @irq: Interrupt line the hardware uses to notify new data has arrived.
* @data: The IIO device associated with the sampling hardware.
*
* Timestamp buffered samples as soon as possible then schedule threaded bottom
* half.
*
* Return: Always successful.
*/
static irqreturn_t zpa2326_handle_irq(int irq, void *data)
{
struct iio_dev *indio_dev = (struct iio_dev *)data;
if (iio_buffer_enabled(indio_dev)) {
/* Timestamping needed for buffered sampling only. */
((struct zpa2326_private *)
iio_priv(indio_dev))->timestamp = iio_get_time_ns(indio_dev);
}
return IRQ_WAKE_THREAD;
}
/**
* zpa2326_handle_threaded_irq() - Interrupt bottom-half handler.
* @irq: Interrupt line the hardware uses to notify new data has arrived.
* @data: The IIO device associated with the sampling hardware.
*
* Mainly ensures interrupt is caused by a real "new sample available"
* condition. This relies upon the ability to perform blocking / sleeping bus
* accesses to slave's registers. This is why zpa2326_handle_threaded_irq() is
* called from within a thread, i.e. not called from hard interrupt context.
*
* When device is using its own internal hardware trigger in continuous sampling
* mode, data are available into hardware FIFO once interrupt has occurred. All
* we have to do is to dispatch the trigger, which in turn will fetch data and
* fill IIO buffer.
*
* When not using its own internal hardware trigger, the device has been
* configured in one-shot mode either by an external trigger or the IIO read_raw
* hook. This means one of the latter is currently waiting for sampling
* completion, in which case we must simply wake it up.
*
* See zpa2326_trigger_handler().
*
* Return:
* %IRQ_NONE - no consistent interrupt happened ;
* %IRQ_HANDLED - there was new samples available.
*/
static irqreturn_t zpa2326_handle_threaded_irq(int irq, void *data)
{
struct iio_dev *indio_dev = (struct iio_dev *)data;
struct zpa2326_private *priv = iio_priv(indio_dev);
unsigned int val;
bool cont;
irqreturn_t ret = IRQ_NONE;
/*
* Are we using our own internal trigger in triggered buffer mode, i.e.,
* currently working in continuous sampling mode ?
*/
cont = (iio_buffer_enabled(indio_dev) &&
iio_trigger_using_own(indio_dev));
/*
* Device works according to a level interrupt scheme: reading interrupt
* status de-asserts interrupt line.
*/
priv->result = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);
if (priv->result < 0) {
if (cont)
return IRQ_NONE;
goto complete;
}
/* Data ready is the only interrupt source we requested. */
if (!(val & ZPA2326_INT_SOURCE_DATA_READY)) {
/*
* Interrupt happened but no new sample available: likely caused
* by spurious interrupts, in which case, returning IRQ_NONE
* allows to benefit from the generic spurious interrupts
* handling.
*/
zpa2326_warn(indio_dev, "unexpected interrupt status %02x",
val);
if (cont)
return IRQ_NONE;
priv->result = -ENODATA;
goto complete;
}
/* New sample available: dispatch internal trigger consumers. */
iio_trigger_poll_chained(priv->trigger);
if (cont)
/*
* Internal hardware trigger has been scheduled above : it will
* fetch data on its own.
*/
return IRQ_HANDLED;
ret = IRQ_HANDLED;
complete:
/*
* Wake up direct or externaly triggered buffer mode waiters: see
* zpa2326_sample_oneshot() and zpa2326_trigger_handler().
*/
complete(&priv->data_ready);
return ret;
}
/**
* zpa2326_wait_oneshot_completion() - Wait for oneshot data ready interrupt.
* @indio_dev: The IIO device associated with the sampling hardware.
* @private: Internal private state related to @indio_dev.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_wait_oneshot_completion(const struct iio_dev *indio_dev,
struct zpa2326_private *private)
{
unsigned int val;
long timeout;
zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt");
timeout = wait_for_completion_interruptible_timeout(
&private->data_ready, ZPA2326_CONVERSION_JIFFIES);
if (timeout > 0)
/*
* Interrupt handler completed before timeout: return operation
* status.
*/
return private->result;
/* Clear all interrupts just to be sure. */
regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);
if (!timeout) {
/* Timed out. */
zpa2326_warn(indio_dev, "no one shot interrupt occurred (%ld)",
timeout);
return -ETIME;
}
zpa2326_warn(indio_dev, "wait for one shot interrupt cancelled");
return -ERESTARTSYS;
}
static int zpa2326_init_managed_irq(struct device *parent,
struct iio_dev *indio_dev,
struct zpa2326_private *private,
int irq)
{
int err;
private->irq = irq;
if (irq <= 0) {
/*
* Platform declared no interrupt line: device will be polled
* for data availability.
*/
dev_info(parent, "no interrupt found, running in polling mode");
return 0;
}
init_completion(&private->data_ready);
/* Request handler to be scheduled into threaded interrupt context. */
err = devm_request_threaded_irq(parent, irq, zpa2326_handle_irq,
zpa2326_handle_threaded_irq,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
dev_name(parent), indio_dev);
if (err) {
dev_err(parent, "failed to request interrupt %d (%d)", irq,
err);
return err;
}
dev_info(parent, "using interrupt %d", irq);
return 0;
}
/**
* zpa2326_poll_oneshot_completion() - Actively poll for one shot data ready.
* @indio_dev: The IIO device associated with the sampling hardware.
*
* Loop over registers content to detect end of sampling cycle. Used when DT
* declared no valid interrupt lines.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_poll_oneshot_completion(const struct iio_dev *indio_dev)
{
unsigned long tmout = jiffies + ZPA2326_CONVERSION_JIFFIES;
struct regmap *regs = ((struct zpa2326_private *)
iio_priv(indio_dev))->regmap;
unsigned int val;
int err;
zpa2326_dbg(indio_dev, "polling for one shot completion");
/*
* At least, 100 ms is needed for the device to complete its one-shot
* cycle.
*/
if (msleep_interruptible(100))
return -ERESTARTSYS;
/* Poll for conversion completion in hardware. */
while (true) {
err = regmap_read(regs, ZPA2326_CTRL_REG0_REG, &val);
if (err < 0)
goto err;
if (!(val & ZPA2326_CTRL_REG0_ONE_SHOT))
/* One-shot bit self clears at conversion end. */
break;
if (time_after(jiffies, tmout)) {
/* Prevent from waiting forever : let's time out. */
err = -ETIME;
goto err;
}
usleep_range(10000, 20000);
}
/*
* In oneshot mode, pressure sample availability guarantees that
* temperature conversion has also completed : just check pressure
* status bit to keep things simple.
*/
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
if (err < 0)
goto err;
if (!(val & ZPA2326_STATUS_P_DA)) {
/* No sample available. */
err = -ENODATA;
goto err;
}
return 0;
err:
zpa2326_warn(indio_dev, "failed to poll one shot completion (%d)", err);
return err;
}
/**
* zpa2326_fetch_raw_sample() - Retrieve a raw sample and convert it to CPU
* endianness.
* @indio_dev: The IIO device associated with the sampling hardware.
* @type: Type of measurement / channel to fetch from.
* @value: Sample output.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_fetch_raw_sample(const struct iio_dev *indio_dev,
enum iio_chan_type type,
int *value)
{
struct regmap *regs = ((struct zpa2326_private *)
iio_priv(indio_dev))->regmap;
int err;
switch (type) {
case IIO_PRESSURE:
zpa2326_dbg(indio_dev, "fetching raw pressure sample");
err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, value,
3);
if (err) {
zpa2326_warn(indio_dev, "failed to fetch pressure (%d)",
err);
return err;
}
/* Pressure is a 24 bits wide little-endian unsigned int. */
*value = (((u8 *)value)[2] << 16) | (((u8 *)value)[1] << 8) |
((u8 *)value)[0];
return IIO_VAL_INT;
case IIO_TEMP:
zpa2326_dbg(indio_dev, "fetching raw temperature sample");
err = regmap_bulk_read(regs, ZPA2326_TEMP_OUT_L_REG, value, 2);
if (err) {
zpa2326_warn(indio_dev,
"failed to fetch temperature (%d)", err);
return err;
}
/* Temperature is a 16 bits wide little-endian signed int. */
*value = (int)le16_to_cpup((__le16 *)value);
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
/**
* zpa2326_sample_oneshot() - Perform a complete one shot sampling cycle.
* @indio_dev: The IIO device associated with the sampling hardware.
* @type: Type of measurement / channel to fetch from.
* @value: Sample output.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_sample_oneshot(struct iio_dev *indio_dev,
enum iio_chan_type type,
int *value)
{
int ret;
struct zpa2326_private *priv;
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = zpa2326_resume(indio_dev);
if (ret < 0)
goto release;
priv = iio_priv(indio_dev);
if (ret > 0) {
/*
* We were already power supplied. Just clear hardware FIFO to
* get rid of samples acquired during previous rounds (if any).
* Sampling operation always generates both temperature and
* pressure samples. The latter are always enqueued into
* hardware FIFO. This may lead to situations were pressure
* samples still sit into FIFO when previous cycle(s) fetched
* temperature data only.
* Hence, we need to clear hardware FIFO content to prevent from
* getting outdated values at the end of current cycle.
*/
if (type == IIO_PRESSURE) {
ret = zpa2326_clear_fifo(indio_dev, 0);
if (ret)
goto suspend;
}
} else {
/*
* We have just been power supplied, i.e. device is in default
* "out of reset" state, meaning we need to reconfigure it
* entirely.
*/
ret = zpa2326_config_oneshot(indio_dev, priv->irq);
if (ret)
goto suspend;
}
/* Start a sampling cycle in oneshot mode. */
ret = zpa2326_start_oneshot(indio_dev);
if (ret)
goto suspend;
/* Wait for sampling cycle to complete. */
if (priv->irq > 0)
ret = zpa2326_wait_oneshot_completion(indio_dev, priv);
else
ret = zpa2326_poll_oneshot_completion(indio_dev);
if (ret)
goto suspend;
/* Retrieve raw sample value and convert it to CPU endianness. */
ret = zpa2326_fetch_raw_sample(indio_dev, type, value);
suspend:
zpa2326_suspend(indio_dev);
release:
iio_device_release_direct_mode(indio_dev);
return ret;
}
/**
* zpa2326_trigger_handler() - Perform an IIO buffered sampling round in one
* shot mode.
* @irq: The software interrupt assigned to @data
* @data: The IIO poll function dispatched by external trigger our device is
* attached to.
*
* Bottom-half handler called by the IIO trigger to which our device is
* currently attached. Allows us to synchronize this device buffered sampling
* either with external events (such as timer expiration, external device sample
* ready, etc...) or with its own interrupt (internal hardware trigger).
*
* When using an external trigger, basically run the same sequence of operations
* as for zpa2326_sample_oneshot() with the following hereafter. Hardware FIFO
* is not cleared since already done at buffering enable time and samples
* dequeueing always retrieves the most recent value.
*
* Otherwise, when internal hardware trigger has dispatched us, just fetch data
* from hardware FIFO.
*
* Fetched data will pushed unprocessed to IIO buffer since samples conversion
* is delegated to userspace in buffered mode (endianness, etc...).
*
* Return:
* %IRQ_NONE - no consistent interrupt happened ;
* %IRQ_HANDLED - there was new samples available.
*/
static irqreturn_t zpa2326_trigger_handler(int irq, void *data)
{
struct iio_dev *indio_dev = ((struct iio_poll_func *)
data)->indio_dev;
struct zpa2326_private *priv = iio_priv(indio_dev);
bool cont;
/*
* We have been dispatched, meaning we are in triggered buffer mode.
* Using our own internal trigger implies we are currently in continuous
* hardware sampling mode.
*/
cont = iio_trigger_using_own(indio_dev);
if (!cont) {
/* On demand sampling : start a one shot cycle. */
if (zpa2326_start_oneshot(indio_dev))
goto out;
/* Wait for sampling cycle to complete. */
if (priv->irq <= 0) {
/* No interrupt available: poll for completion. */
if (zpa2326_poll_oneshot_completion(indio_dev))
goto out;
/* Only timestamp sample once it is ready. */
priv->timestamp = iio_get_time_ns(indio_dev);
} else {
/* Interrupt handlers will timestamp for us. */
if (zpa2326_wait_oneshot_completion(indio_dev, priv))
goto out;
}
}
/* Enqueue to IIO buffer / userspace. */
zpa2326_fill_sample_buffer(indio_dev, priv);
out:
if (!cont)
/* Don't switch to low power if sampling continuously. */
zpa2326_sleep(indio_dev);
/* Inform attached trigger we are done. */
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
/**
* zpa2326_preenable_buffer() - Prepare device for configuring triggered
* sampling
* modes.
* @indio_dev: The IIO device associated with the sampling hardware.
*
* Basically power up device.
* Called with IIO device's lock held.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_preenable_buffer(struct iio_dev *indio_dev)
{
int ret = zpa2326_resume(indio_dev);
if (ret < 0)
return ret;
/* Tell zpa2326_postenable_buffer() if we have just been powered on. */
((struct zpa2326_private *)
iio_priv(indio_dev))->waken = iio_priv(indio_dev);
return 0;
}
/**
* zpa2326_postenable_buffer() - Configure device for triggered sampling.
* @indio_dev: The IIO device associated with the sampling hardware.
*
* Basically setup one-shot mode if plugging external trigger.
* Otherwise, let internal trigger configure continuous sampling :
* see zpa2326_set_trigger_state().
*
* If an error is returned, IIO layer will call our postdisable hook for us,
* i.e. no need to explicitly power device off here.
* Called with IIO device's lock held.
*
* Called with IIO device's lock held.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_postenable_buffer(struct iio_dev *indio_dev)
{
const struct zpa2326_private *priv = iio_priv(indio_dev);
int err;
if (!priv->waken) {
/*
* We were already power supplied. Just clear hardware FIFO to
* get rid of samples acquired during previous rounds (if any).
*/
err = zpa2326_clear_fifo(indio_dev, 0);
if (err)
goto err;
}
if (!iio_trigger_using_own(indio_dev) && priv->waken) {
/*
* We are using an external trigger and we have just been
* powered up: reconfigure one-shot mode.
*/
err = zpa2326_config_oneshot(indio_dev, priv->irq);
if (err)
goto err;
}
/* Plug our own trigger event handler. */
err = iio_triggered_buffer_postenable(indio_dev);
if (err)
goto err;
return 0;
err:
zpa2326_err(indio_dev, "failed to enable buffering (%d)", err);
return err;
}
static int zpa2326_postdisable_buffer(struct iio_dev *indio_dev)
{
zpa2326_suspend(indio_dev);
return 0;
}
static const struct iio_buffer_setup_ops zpa2326_buffer_setup_ops = {
.preenable = zpa2326_preenable_buffer,
.postenable = zpa2326_postenable_buffer,
.predisable = iio_triggered_buffer_predisable,
.postdisable = zpa2326_postdisable_buffer
};
/**
* zpa2326_set_trigger_state() - Start / stop continuous sampling.
* @trig: The trigger being attached to IIO device associated with the sampling
* hardware.
* @state: Tell whether to start (true) or stop (false)
*
* Basically enable / disable hardware continuous sampling mode.
*
* Called with IIO device's lock held at postenable() or predisable() time.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_set_trigger_state(struct iio_trigger *trig, bool state)
{
const struct iio_dev *indio_dev = dev_get_drvdata(
trig->dev.parent);
const struct zpa2326_private *priv = iio_priv(indio_dev);
int err;
if (!state) {
/*
* Switch trigger off : in case of failure, interrupt is left
* disabled in order to prevent handler from accessing released
* resources.
*/
unsigned int val;
/*
* As device is working in continuous mode, handlers may be
* accessing resources we are currently freeing...
* Prevent this by disabling interrupt handlers and ensure
* the device will generate no more interrupts unless explicitly
* required to, i.e. by restoring back to default one shot mode.
*/
disable_irq(priv->irq);
/*
* Disable continuous sampling mode to restore settings for
* one shot / direct sampling operations.
*/
err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,
zpa2326_highest_frequency()->odr);
if (err)
return err;
/*
* Now that device won't generate interrupts on its own,
* acknowledge any currently active interrupts (may happen on
* rare occasions while stopping continuous mode).
*/
err = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);
if (err < 0)
return err;
/*
* Re-enable interrupts only if we can guarantee the device will
* generate no more interrupts to prevent handlers from
* accessing released resources.
*/
enable_irq(priv->irq);
zpa2326_dbg(indio_dev, "continuous mode stopped");
} else {
/*
* Switch trigger on : start continuous sampling at required
* frequency.
*/
if (priv->waken) {
/* Enable interrupt if getting out of reset. */
err = regmap_write(priv->regmap, ZPA2326_CTRL_REG1_REG,
(u8)
~ZPA2326_CTRL_REG1_MASK_DATA_READY);
if (err)
return err;
}
/* Enable continuous sampling at specified frequency. */
err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,
ZPA2326_CTRL_REG3_ENABLE_MEAS |
priv->frequency->odr);
if (err)
return err;
zpa2326_dbg(indio_dev, "continuous mode setup @%dHz",
priv->frequency->hz);
}
return 0;
}
static const struct iio_trigger_ops zpa2326_trigger_ops = {
.owner = THIS_MODULE,
.set_trigger_state = zpa2326_set_trigger_state,
};
/**
* zpa2326_init_trigger() - Create an interrupt driven / hardware trigger
* allowing to notify external devices a new sample is
* ready.
* @parent: Hardware sampling device @indio_dev is a child of.
* @indio_dev: The IIO device associated with the sampling hardware.
* @private: Internal private state related to @indio_dev.
* @irq: Optional interrupt line the hardware uses to notify new data
* samples are ready. Negative or zero values indicate no interrupts
* are available, meaning polling is required.
*
* Only relevant when DT declares a valid interrupt line.
*
* Return: Zero when successful, a negative error code otherwise.
*/
static int zpa2326_init_managed_trigger(struct device *parent,
struct iio_dev *indio_dev,
struct zpa2326_private *private,
int irq)
{
struct iio_trigger *trigger;
int ret;
if (irq <= 0)
return 0;
trigger = devm_iio_trigger_alloc(parent, "%s-dev%d",
indio_dev->name, indio_dev->id);
if (!trigger)
return -ENOMEM;
/* Basic setup. */
trigger->dev.parent = parent;
trigger->ops = &zpa2326_trigger_ops;
private->trigger = trigger;
/* Register to triggers space. */
ret = devm_iio_trigger_register(parent, trigger);
if (ret)
dev_err(parent, "failed to register hardware trigger (%d)",
ret);
return ret;
}
static int zpa2326_get_frequency(const struct iio_dev *indio_dev)
{
return ((struct zpa2326_private *)iio_priv(indio_dev))->frequency->hz;
}
static int zpa2326_set_frequency(struct iio_dev *indio_dev, int hz)
{
struct zpa2326_private *priv = iio_priv(indio_dev);
int freq;
int err;
/* Check if requested frequency is supported. */
for (freq = 0; freq < ARRAY_SIZE(zpa2326_sampling_frequencies); freq++)
if (zpa2326_sampling_frequencies[freq].hz == hz)
break;
if (freq == ARRAY_SIZE(zpa2326_sampling_frequencies))
return -EINVAL;
/* Don't allow changing frequency if buffered sampling is ongoing. */
err = iio_device_claim_direct_mode(indio_dev);
if (err)
return err;
priv->frequency = &zpa2326_sampling_frequencies[freq];
iio_device_release_direct_mode(indio_dev);
return 0;
}
/* Expose supported hardware sampling frequencies (Hz) through sysfs. */
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1 5 11 23");
static struct attribute *zpa2326_attributes[] = {
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
NULL
};
static const struct attribute_group zpa2326_attribute_group = {
.attrs = zpa2326_attributes,
};
static int zpa2326_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
switch (mask) {
case IIO_CHAN_INFO_RAW:
return zpa2326_sample_oneshot(indio_dev, chan->type, val);
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_PRESSURE:
/*
* Pressure resolution is 1/64 Pascal. Scale to kPascal
* as required by IIO ABI.
*/
*val = 1;
*val2 = 64000;
return IIO_VAL_FRACTIONAL;
case IIO_TEMP:
/*
* Temperature follows the equation:
* Temp[degC] = Tempcode * 0.00649 - 176.83
* where:
* Tempcode is composed the raw sampled 16 bits.
*
* Hence, to produce a temperature in milli-degrees
* Celsius according to IIO ABI, we need to apply the
* following equation to raw samples:
* Temp[milli degC] = (Tempcode + Offset) * Scale
* where:
* Offset = -176.83 / 0.00649
* Scale = 0.00649 * 1000
*/
*val = 6;
*val2 = 490000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_OFFSET:
switch (chan->type) {
case IIO_TEMP:
*val = -17683000;
*val2 = 649;
return IIO_VAL_FRACTIONAL;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SAMP_FREQ:
*val = zpa2326_get_frequency(indio_dev);
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int zpa2326_write_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
int val,
int val2,
long mask)
{
if ((mask != IIO_CHAN_INFO_SAMP_FREQ) || val2)
return -EINVAL;
return zpa2326_set_frequency(indio_dev, val);
}
static const struct iio_chan_spec zpa2326_channels[] = {
[0] = {
.type = IIO_PRESSURE,
.scan_index = 0,
.scan_type = {
.sign = 'u',
.realbits = 24,
.storagebits = 32,
.endianness = IIO_LE,
},
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
},
[1] = {
.type = IIO_TEMP,
.scan_index = 1,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_LE,
},
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
},
[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
};
static const struct iio_info zpa2326_info = {
.driver_module = THIS_MODULE,
.attrs = &zpa2326_attribute_group,
.read_raw = zpa2326_read_raw,
.write_raw = zpa2326_write_raw,
};
static struct iio_dev *zpa2326_create_managed_iiodev(struct device *device,
const char *name,
struct regmap *regmap)
{
struct iio_dev *indio_dev;
/* Allocate space to hold IIO device internal state. */
indio_dev = devm_iio_device_alloc(device,
sizeof(struct zpa2326_private));
if (!indio_dev)
return NULL;
/* Setup for userspace synchronous on demand sampling. */
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->dev.parent = device;
indio_dev->channels = zpa2326_channels;
indio_dev->num_channels = ARRAY_SIZE(zpa2326_channels);
indio_dev->name = name;
indio_dev->info = &zpa2326_info;
return indio_dev;
}
int zpa2326_probe(struct device *parent,
const char *name,
int irq,
unsigned int hwid,
struct regmap *regmap)
{
struct iio_dev *indio_dev;
struct zpa2326_private *priv;
int err;
unsigned int id;
indio_dev = zpa2326_create_managed_iiodev(parent, name, regmap);
if (!indio_dev)
return -ENOMEM;
priv = iio_priv(indio_dev);
priv->vref = devm_regulator_get(parent, "vref");
if (IS_ERR(priv->vref))
return PTR_ERR(priv->vref);
priv->vdd = devm_regulator_get(parent, "vdd");
if (IS_ERR(priv->vdd))
return PTR_ERR(priv->vdd);
/* Set default hardware sampling frequency to highest rate supported. */
priv->frequency = zpa2326_highest_frequency();
/*
* Plug device's underlying bus abstraction : this MUST be set before
* registering interrupt handlers since an interrupt might happen if
* power up sequence is not properly applied.
*/
priv->regmap = regmap;
err = devm_iio_triggered_buffer_setup(parent, indio_dev, NULL,
zpa2326_trigger_handler,
&zpa2326_buffer_setup_ops);
if (err)
return err;
err = zpa2326_init_managed_trigger(parent, indio_dev, priv, irq);
if (err)
return err;
err = zpa2326_init_managed_irq(parent, indio_dev, priv, irq);
if (err)
return err;
/* Power up to check device ID and perform initial hardware setup. */
err = zpa2326_power_on(indio_dev, priv);
if (err)
return err;
/* Read id register to check we are talking to the right slave. */
err = regmap_read(regmap, ZPA2326_DEVICE_ID_REG, &id);
if (err)
goto sleep;
if (id != hwid) {
dev_err(parent, "found device with unexpected id %02x", id);
err = -ENODEV;
goto sleep;
}
err = zpa2326_config_oneshot(indio_dev, irq);
if (err)
goto sleep;
/* Setup done : go sleeping. Device will be awaken upon user request. */
err = zpa2326_sleep(indio_dev);
if (err)
goto poweroff;
dev_set_drvdata(parent, indio_dev);
zpa2326_init_runtime(parent);
err = iio_device_register(indio_dev);
if (err) {
zpa2326_fini_runtime(parent);
goto poweroff;
}
return 0;
sleep:
/* Put to sleep just in case power regulators are "dummy" ones. */
zpa2326_sleep(indio_dev);
poweroff:
zpa2326_power_off(indio_dev, priv);
return err;
}
EXPORT_SYMBOL_GPL(zpa2326_probe);
void zpa2326_remove(const struct device *parent)
{
struct iio_dev *indio_dev = dev_get_drvdata(parent);
iio_device_unregister(indio_dev);
zpa2326_fini_runtime(indio_dev->dev.parent);
zpa2326_sleep(indio_dev);
zpa2326_power_off(indio_dev, iio_priv(indio_dev));
}
EXPORT_SYMBOL_GPL(zpa2326_remove);
MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
MODULE_DESCRIPTION("Core driver for Murata ZPA2326 pressure sensor");
MODULE_LICENSE("GPL v2");
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