/* * OF helpers for the GPIO API * * Copyright (c) 2007-2008 MontaVista Software, Inc. * Copyright (c) 2017, NVIDIA Corporation. All rights reserved. * * Author: Anton Vorontsov * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "gpiolib.h" static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data) { struct of_phandle_args *gpiospec = data; return chip->gpiodev->dev.of_node == gpiospec->np && chip->of_xlate && chip->of_xlate(chip, gpiospec, NULL) >= 0; } static struct gpio_chip *of_find_gpiochip_by_xlate( struct of_phandle_args *gpiospec) { return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate); } static int of_gpiochip_match_node(struct gpio_chip *chip, void *data) { struct of_phandle_args *gpiospec = data; return chip->gpiodev->dev.of_node == gpiospec->np; } static struct gpio_chip *of_find_gpiochip_by_node( struct of_phandle_args *gpiospec) { return gpiochip_find(gpiospec, of_gpiochip_match_node); } static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, struct of_phandle_args *gpiospec, enum of_gpio_flags *flags) { int ret; if (chip->of_gpio_n_cells != gpiospec->args_count) return ERR_PTR(-EINVAL); ret = chip->of_xlate(chip, gpiospec, flags); if (ret < 0) return ERR_PTR(ret); return gpiochip_get_desc(chip, ret); } /** * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API * @np: device node to get GPIO from * @propname: property name containing gpio specifier(s) * @index: index of the GPIO * @flags: a flags pointer to fill in * * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno * value on the error condition. If @flags is not NULL the function also fills * in flags for the GPIO. */ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, const char *propname, int index, enum of_gpio_flags *flags) { struct of_phandle_args gpiospec; struct gpio_chip *chip; struct gpio_desc *desc; int ret; ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, &gpiospec); if (ret) { pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n", __func__, propname, np ? np->full_name : NULL, index); return ERR_PTR(ret); } chip = of_find_gpiochip_by_xlate(&gpiospec); if (!chip) { desc = ERR_PTR(-EPROBE_DEFER); goto out; } desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags); if (IS_ERR(desc)) goto out; pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n", __func__, propname, np->full_name, index, PTR_ERR_OR_ZERO(desc)); out: of_node_put(gpiospec.np); return desc; } /** * of_get_chip_from_node() - Get a GPIO chip * @np: device node to get gpio chip * * Returns GPIO chip structure, this is simple API to retrieve chip * structure from the device node. */ struct gpio_chip *of_get_chip_from_node(struct device_node *np) { struct of_phandle_args gpiospec = {0}; struct gpio_chip *chip; gpiospec.np = np; chip = of_find_gpiochip_by_node(&gpiospec); if (!chip) return ERR_PTR(-EPROBE_DEFER); return chip; } EXPORT_SYMBOL(of_get_chip_from_node); int of_get_named_gpio_flags(struct device_node *np, const char *list_name, int index, enum of_gpio_flags *flags) { struct gpio_desc *desc; desc = of_get_named_gpiod_flags(np, list_name, index, flags); if (IS_ERR(desc)) return PTR_ERR(desc); else return desc_to_gpio(desc); } EXPORT_SYMBOL(of_get_named_gpio_flags); static int of_gpio_get_gpio_cells_size(struct device_node *chip_np) { u32 ncells; int ret; ret = of_property_read_u32(chip_np, "#gpio-cells", &ncells); if (ret) return ret; if (ncells > MAX_PHANDLE_ARGS) return -EINVAL; return ncells; } struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) { char prop_name[32]; /* 32 is max size of property name */ enum of_gpio_flags of_flags; struct gpio_desc *desc; unsigned int i; for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { if (con_id) snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id, gpio_suffixes[i]); else snprintf(prop_name, sizeof(prop_name), "%s", gpio_suffixes[i]); desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, &of_flags); if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT)) break; } if (IS_ERR(desc)) return desc; if (of_flags & OF_GPIO_ACTIVE_LOW) *flags |= GPIO_ACTIVE_LOW; if (of_flags & OF_GPIO_SINGLE_ENDED) { if (of_flags & OF_GPIO_OPEN_DRAIN) *flags |= GPIO_OPEN_DRAIN; else *flags |= GPIO_OPEN_SOURCE; } return desc; } /** * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API * @np: device node to get GPIO from * @chip: GPIO chip whose hog is parsed * @name: GPIO line name * @lflags: gpio_lookup_flags - returned from of_find_gpio() or * of_parse_own_gpio() * @dflags: gpiod_flags - optional GPIO initialization flags * * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno * value on the error condition. */ static struct gpio_desc *of_parse_own_gpio(struct device_node *np, struct gpio_chip *chip, const char **name, int gpio_index, enum gpio_lookup_flags *lflags, enum gpiod_flags *dflags) { struct device_node *chip_np; enum of_gpio_flags xlate_flags; struct of_phandle_args gpiospec; struct gpio_desc *desc; int ncells; int i, start_index, ret; chip_np = chip->of_node; if (!chip_np) return ERR_PTR(-EINVAL); xlate_flags = 0; *lflags = 0; *dflags = 0; ncells = of_gpio_get_gpio_cells_size(chip_np); if (ncells < 0) return ERR_PTR(ncells); start_index = ncells * gpio_index; gpiospec.np = chip_np; gpiospec.args_count = ncells; for (i = 0; i < ncells; i++) { ret = of_property_read_u32_index(np, "gpios", start_index + i, &gpiospec.args[i]); if (ret) return ERR_PTR(ret); } desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags); if (IS_ERR(desc)) return desc; if (xlate_flags & OF_GPIO_ACTIVE_LOW) *lflags |= GPIO_ACTIVE_LOW; if (of_property_read_bool(np, "input")) *dflags |= GPIOD_IN; else if (of_property_read_bool(np, "output-low")) *dflags |= GPIOD_OUT_LOW; else if (of_property_read_bool(np, "output-high")) *dflags |= GPIOD_OUT_HIGH; else if (of_property_read_bool(np, "function")) *dflags = 0; else { pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n", desc_to_gpio(desc), np->name); return ERR_PTR(-EINVAL); } if (name && of_property_read_string_index(np, "line-name", gpio_index, name)) *name = np->name; return desc; } /** * of_gpiochip_set_names() - set up the names of the lines * @chip: GPIO chip whose lines should be named, if possible */ static void of_gpiochip_set_names(struct gpio_chip *gc) { struct gpio_device *gdev = gc->gpiodev; struct device_node *np = gc->of_node; int i; int nstrings; nstrings = of_property_count_strings(np, "gpio-line-names"); if (nstrings <= 0) /* Lines names not present */ return; /* This is normally not what you want */ if (gdev->ngpio != nstrings) dev_info(&gdev->dev, "gpio-line-names specifies %d line " "names but there are %d lines on the chip\n", nstrings, gdev->ngpio); /* * Make sure to not index beyond the end of the number of descriptors * of the GPIO device. */ for (i = 0; i < gdev->ngpio; i++) { const char *name; int ret; ret = of_property_read_string_index(np, "gpio-line-names", i, &name); if (ret) { if (ret != -ENODATA) dev_err(&gdev->dev, "unable to name line %d: %d\n", i, ret); break; } gdev->descs[i].name = name; } } /** * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions * @chip: gpio chip to act on * * This is only used by of_gpiochip_add to request/set GPIO initial * configuration. * It retures error if it fails otherwise 0 on success. */ static int of_gpiochip_scan_gpios(struct gpio_chip *chip) { struct gpio_desc *desc = NULL; struct device_node *np; const char *name; enum gpio_lookup_flags lflags; enum gpiod_flags dflags; int ret; int i, ncells, ngpios; ncells = of_gpio_get_gpio_cells_size(chip->of_node); if (ncells < 0) return 0; for_each_available_child_of_node(chip->of_node, np) { if (!of_property_read_bool(np, "gpio-hog")) continue; ngpios = of_property_count_u32_elems(np, "gpios"); if (ngpios < 0) continue; if (ngpios % ncells) { dev_warn(chip->parent, "Invalid GPIO entries at %s\n", np->name); continue; } ngpios /= ncells; for (i = 0; i < ngpios; i++) { desc = of_parse_own_gpio(np, chip, &name, i, &lflags, &dflags); if (IS_ERR(desc)) continue; /* dflags is 0 for making pin in non-gpio mode */ if (!dflags) { ret = chip->request(chip, gpio_chip_hwgpio(desc)); if (!ret) chip->free(chip, gpio_chip_hwgpio(desc)); continue; } ret = gpiod_hog(desc, name, lflags, dflags); if (ret < 0) return ret; } } return 0; } /** * of_gpiochip_suspend - Suspend GPIOs * @chip: gpio chip to act on * */ int of_gpiochip_suspend(struct gpio_chip *chip) { struct gpio_desc *desc = NULL; struct device_node *np; const char *name; enum gpio_lookup_flags lflags; enum gpiod_flags dflags; int ret; int i, ncells, ngpios; ncells = of_gpio_get_gpio_cells_size(chip->of_node); if (ncells < 0) return 0; for_each_available_child_of_node(chip->of_node, np) { if (!of_property_read_bool(np, "gpio-suspend")) continue; ngpios = of_property_count_u32_elems(np, "gpios"); if (ngpios < 0) continue; if (ngpios % ncells) { dev_warn(chip->parent, "Invalid GPIO entries at %s\n", np->name); continue; } ngpios /= ncells; for (i = 0; i < ngpios; i++) { desc = of_parse_own_gpio(np, chip, &name, i, &lflags, &dflags); if (IS_ERR(desc)) continue; if (of_property_read_bool(np, "suspend-input")) { dflags &= ~(GPIOD_OUT_HIGH | GPIOD_OUT_LOW); dflags |= GPIOD_IN; } else if (of_property_read_bool(np, "suspend-output-low")) { dflags &= ~(GPIOD_IN | GPIOD_OUT_HIGH); dflags |= GPIOD_OUT_LOW; } else if (of_property_read_bool(np, "suspend-output-high")) { dflags &= ~(GPIOD_IN | GPIOD_OUT_LOW); dflags |= GPIOD_OUT_HIGH; } if (chip->suspend_configure) { ret = chip->suspend_configure(chip, gpio_chip_hwgpio(desc), dflags); } else { if (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ret = chip->direction_output(chip, gpio_chip_hwgpio(desc), dflags & GPIOD_FLAGS_BIT_DIR_VAL); else ret = chip->direction_input(chip, gpio_chip_hwgpio(desc)); } if (ret < 0) dev_warn(chip->parent, "Failed to configure gpio %d of node %s: %d\n", i, np->name, ret); } } return 0; } /** * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags * @gc: pointer to the gpio_chip structure * @np: device node of the GPIO chip * @gpio_spec: gpio specifier as found in the device tree * @flags: a flags pointer to fill in * * This is simple translation function, suitable for the most 1:1 mapped * gpio chips. This function performs only one sanity check: whether gpio * is less than ngpios (that is specified in the gpio_chip). */ int of_gpio_simple_xlate(struct gpio_chip *gc, const struct of_phandle_args *gpiospec, u32 *flags) { /* * We're discouraging gpio_cells < 2, since that way you'll have to * write your own xlate function (that will have to retrieve the GPIO * number and the flags from a single gpio cell -- this is possible, * but not recommended). */ if (gc->of_gpio_n_cells < 2) { WARN_ON(1); return -EINVAL; } if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) return -EINVAL; if (gpiospec->args[0] >= gc->ngpio) return -EINVAL; if (flags) *flags = gpiospec->args[1]; return gpiospec->args[0]; } EXPORT_SYMBOL(of_gpio_simple_xlate); /** * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank) * @np: device node of the GPIO chip * @mm_gc: pointer to the of_mm_gpio_chip allocated structure * @data: driver data to store in the struct gpio_chip * * To use this function you should allocate and fill mm_gc with: * * 1) In the gpio_chip structure: * - all the callbacks * - of_gpio_n_cells * - of_xlate callback (optional) * * 3) In the of_mm_gpio_chip structure: * - save_regs callback (optional) * * If succeeded, this function will map bank's memory and will * do all necessary work for you. Then you'll able to use .regs * to manage GPIOs from the callbacks. */ int of_mm_gpiochip_add_data(struct device_node *np, struct of_mm_gpio_chip *mm_gc, void *data) { int ret = -ENOMEM; struct gpio_chip *gc = &mm_gc->gc; gc->label = kstrdup(np->full_name, GFP_KERNEL); if (!gc->label) goto err0; mm_gc->regs = of_iomap(np, 0); if (!mm_gc->regs) goto err1; gc->base = -1; if (mm_gc->save_regs) mm_gc->save_regs(mm_gc); mm_gc->gc.of_node = np; ret = gpiochip_add_data(gc, data); if (ret) goto err2; return 0; err2: iounmap(mm_gc->regs); err1: kfree(gc->label); err0: pr_err("%s: GPIO chip registration failed with status %d\n", np->full_name, ret); return ret; } EXPORT_SYMBOL(of_mm_gpiochip_add_data); /** * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank) * @mm_gc: pointer to the of_mm_gpio_chip allocated structure */ void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) { struct gpio_chip *gc = &mm_gc->gc; if (!mm_gc) return; gpiochip_remove(gc); iounmap(mm_gc->regs); kfree(gc->label); } EXPORT_SYMBOL(of_mm_gpiochip_remove); #ifdef CONFIG_PINCTRL static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { struct device_node *np = chip->of_node; struct of_phandle_args pinspec; struct pinctrl_dev *pctldev; int index = 0, ret; const char *name; static const char group_names_propname[] = "gpio-ranges-group-names"; struct property *group_names; if (!np) return 0; group_names = of_find_property(np, group_names_propname, NULL); for (;; index++) { ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, index, &pinspec); if (ret) break; pctldev = of_pinctrl_get(pinspec.np); of_node_put(pinspec.np); if (!pctldev) return -EPROBE_DEFER; if (pinspec.args[2]) { if (group_names) { of_property_read_string_index(np, group_names_propname, index, &name); if (strlen(name)) { pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n", np->full_name); break; } } /* npins != 0: linear range */ ret = gpiochip_add_pin_range(chip, pinctrl_dev_get_devname(pctldev), pinspec.args[0], pinspec.args[1], pinspec.args[2]); if (ret) return ret; } else { /* npins == 0: special range */ if (pinspec.args[1]) { pr_err("%s: Illegal gpio-range format.\n", np->full_name); break; } if (!group_names) { pr_err("%s: GPIO group range requested but no %s property.\n", np->full_name, group_names_propname); break; } ret = of_property_read_string_index(np, group_names_propname, index, &name); if (ret) break; if (!strlen(name)) { pr_err("%s: Group name of GPIO group range cannot be the empty string.\n", np->full_name); break; } ret = gpiochip_add_pingroup_range(chip, pctldev, pinspec.args[0], name); if (ret) return ret; } } return 0; } #else static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } #endif int of_gpiochip_add(struct gpio_chip *chip) { int status; if ((!chip->of_node) && (chip->parent)) chip->of_node = chip->parent->of_node; if (!chip->of_node) return 0; if (!chip->of_xlate) { chip->of_gpio_n_cells = 2; chip->of_xlate = of_gpio_simple_xlate; } if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) return -EINVAL; status = of_gpiochip_add_pin_range(chip); if (status) return status; /* If the chip defines names itself, these take precedence */ if (!chip->names) of_gpiochip_set_names(chip); of_node_get(chip->of_node); status = of_gpiochip_scan_gpios(chip); if (status) { of_node_put(chip->of_node); gpiochip_remove_pin_ranges(chip); } return status; } void of_gpiochip_remove(struct gpio_chip *chip) { gpiochip_remove_pin_ranges(chip); of_node_put(chip->of_node); }