// SPDX-License-Identifier: GPL-2.0+ /* * OF helpers for the GPIO API * * Copyright (c) 2007-2008 MontaVista Software, Inc. * * Author: Anton Vorontsov <avorontsov@ru.mvista.com> */ #include <linux/device.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/module.h> #include <linux/io.h> #include <linux/gpio/consumer.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_gpio.h> #include <linux/pinctrl/pinctrl.h> #include <linux/slab.h> #include <linux/gpio/machine.h> #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 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); } static void of_gpio_flags_quirks(struct device_node *np, const char *propname, enum of_gpio_flags *flags, int index) { /* * Handle MMC "cd-inverted" and "wp-inverted" semantics. */ if (IS_ENABLED(CONFIG_MMC)) { /* * Active low is the default according to the * SDHCI specification and the device tree * bindings. However the code in the current * kernel was written such that the phandle * flags were always respected, and "cd-inverted" * would invert the flag from the device phandle. */ if (!strcmp(propname, "cd-gpios")) { if (of_property_read_bool(np, "cd-inverted")) *flags ^= OF_GPIO_ACTIVE_LOW; } if (!strcmp(propname, "wp-gpios")) { if (of_property_read_bool(np, "wp-inverted")) *flags ^= OF_GPIO_ACTIVE_LOW; } } /* * Some GPIO fixed regulator quirks. * Note that active low is the default. */ if (IS_ENABLED(CONFIG_REGULATOR) && (of_device_is_compatible(np, "regulator-fixed") || of_device_is_compatible(np, "reg-fixed-voltage") || of_device_is_compatible(np, "regulator-gpio"))) { /* * The regulator GPIO handles are specified such that the * presence or absence of "enable-active-high" solely controls * the polarity of the GPIO line. Any phandle flags must * be actively ignored. */ if (*flags & OF_GPIO_ACTIVE_LOW) { pr_warn("%s GPIO handle specifies active low - ignored\n", of_node_full_name(np)); *flags &= ~OF_GPIO_ACTIVE_LOW; } if (!of_property_read_bool(np, "enable-active-high")) *flags |= OF_GPIO_ACTIVE_LOW; } /* * Legacy open drain handling for fixed voltage regulators. */ if (IS_ENABLED(CONFIG_REGULATOR) && of_device_is_compatible(np, "reg-fixed-voltage") && of_property_read_bool(np, "gpio-open-drain")) { *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN); pr_info("%s uses legacy open drain flag - update the DTS if you can\n", of_node_full_name(np)); } /* * Legacy handling of SPI active high chip select. If we have a * property named "cs-gpios" we need to inspect the child node * to determine if the flags should have inverted semantics. */ if (IS_ENABLED(CONFIG_SPI_MASTER) && of_property_read_bool(np, "cs-gpios")) { struct device_node *child; u32 cs; int ret; for_each_child_of_node(np, child) { ret = of_property_read_u32(child, "reg", &cs); if (!ret) continue; if (cs == index) { /* * SPI children have active low chip selects * by default. This can be specified negatively * by just omitting "spi-cs-high" in the * device node, or actively by tagging on * GPIO_ACTIVE_LOW as flag in the device * tree. If the line is simultaneously * tagged as active low in the device tree * and has the "spi-cs-high" set, we get a * conflict and the "spi-cs-high" flag will * take precedence. */ if (of_property_read_bool(np, "spi-cs-high")) { if (*flags & OF_GPIO_ACTIVE_LOW) { pr_warn("%s GPIO handle specifies active low - ignored\n", of_node_full_name(np)); *flags &= ~OF_GPIO_ACTIVE_LOW; } } else { if (!(*flags & OF_GPIO_ACTIVE_LOW)) pr_info("%s enforce active low on chipselect handle\n", of_node_full_name(np)); *flags |= OF_GPIO_ACTIVE_LOW; } break; } } } } /** * 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_map(np, propname, "gpio", index, &gpiospec); if (ret) { pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n", __func__, propname, np, 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; if (flags) of_gpio_flags_quirks(np, propname, flags, index); pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n", __func__, propname, np, index, PTR_ERR_OR_ZERO(desc)); out: of_node_put(gpiospec.np); return desc; } 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); /* * The SPI GPIO bindings happened before we managed to establish that GPIO * properties should be named "foo-gpios" so we have this special kludge for * them. */ static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id, enum of_gpio_flags *of_flags) { char prop_name[32]; /* 32 is max size of property name */ struct device_node *np = dev->of_node; struct gpio_desc *desc; /* * Hopefully the compiler stubs the rest of the function if this * is false. */ if (!IS_ENABLED(CONFIG_SPI_MASTER)) return ERR_PTR(-ENOENT); /* Allow this specifically for "spi-gpio" devices */ if (!of_device_is_compatible(np, "spi-gpio") || !con_id) return ERR_PTR(-ENOENT); /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */ snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id); desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags); return desc; } /* * Some regulator bindings happened before we managed to establish that GPIO * properties should be named "foo-gpios" so we have this special kludge for * them. */ static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id, enum of_gpio_flags *of_flags) { /* These are the connection IDs we accept as legacy GPIO phandles */ const char *whitelist[] = { "wlf,ldoena", /* Arizona */ "wlf,ldo1ena", /* WM8994 */ "wlf,ldo2ena", /* WM8994 */ }; struct device_node *np = dev->of_node; struct gpio_desc *desc; int i; if (!IS_ENABLED(CONFIG_REGULATOR)) return ERR_PTR(-ENOENT); if (!con_id) return ERR_PTR(-ENOENT); i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id); if (i < 0) return ERR_PTR(-ENOENT); desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags); return desc; } 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; /* Try GPIO property "foo-gpios" and "foo-gpio" */ 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); /* * -EPROBE_DEFER in our case means that we found a * valid GPIO property, but no controller has been * registered so far. * * This means we don't need to look any further for * alternate name conventions, and we should really * preserve the return code for our user to be able to * retry probing later. */ if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER) return desc; if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT)) break; } /* Special handling for SPI GPIOs if used */ if (IS_ERR(desc)) desc = of_find_spi_gpio(dev, con_id, &of_flags); /* Special handling for regulator GPIOs if used */ if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER) desc = of_find_regulator_gpio(dev, con_id, &of_flags); 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; } if (of_flags & OF_GPIO_TRANSITORY) *flags |= GPIO_TRANSITORY; 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 * @idx: Index of the GPIO to parse * @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, unsigned int idx, const char **name, 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; unsigned int i; u32 tmp; int ret; chip_np = chip->of_node; if (!chip_np) return ERR_PTR(-EINVAL); xlate_flags = 0; *lflags = 0; *dflags = 0; ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); if (ret) return ERR_PTR(ret); gpiospec.np = chip_np; gpiospec.args_count = tmp; for (i = 0; i < tmp; i++) { ret = of_property_read_u32_index(np, "gpios", idx * tmp + 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 (xlate_flags & OF_GPIO_TRANSITORY) *lflags |= GPIO_TRANSITORY; 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 { pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n", desc_to_gpio(desc), np); return ERR_PTR(-EINVAL); } if (name && of_property_read_string(np, "line-name", name)) *name = np->name; return desc; } /** * 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 returns 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; unsigned int i; int ret; for_each_available_child_of_node(chip->of_node, np) { if (!of_property_read_bool(np, "gpio-hog")) continue; for (i = 0;; i++) { desc = of_parse_own_gpio(np, chip, i, &name, &lflags, &dflags); if (IS_ERR(desc)) break; ret = gpiod_hog(desc, name, lflags, dflags); if (ret < 0) { of_node_put(np); return ret; } } } return 0; } /** * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags * @gc: pointer to the gpio_chip structure * @gpiospec: 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 = kasprintf(GFP_KERNEL, "%pOF", np); 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("%pOF: GPIO chip registration failed with status %d\n", np, 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); static void of_gpiochip_init_valid_mask(struct gpio_chip *chip) { int len, i; u32 start, count; struct device_node *np = chip->of_node; len = of_property_count_u32_elems(np, "gpio-reserved-ranges"); if (len < 0 || len % 2 != 0) return; for (i = 0; i < len; i += 2) { of_property_read_u32_index(np, "gpio-reserved-ranges", i, &start); of_property_read_u32_index(np, "gpio-reserved-ranges", i + 1, &count); if (start >= chip->ngpio || start + count >= chip->ngpio) continue; bitmap_clear(chip->valid_mask, start, count); } }; #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("%pOF: Group name of numeric GPIO ranges must be the empty string.\n", np); 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("%pOF: Illegal gpio-range format.\n", np); break; } if (!group_names) { pr_err("%pOF: GPIO group range requested but no %s property.\n", np, group_names_propname); break; } ret = of_property_read_string_index(np, group_names_propname, index, &name); if (ret) break; if (!strlen(name)) { pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n", np); 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) 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; of_gpiochip_init_valid_mask(chip); status = of_gpiochip_add_pin_range(chip); if (status) return status; /* If the chip defines names itself, these take precedence */ if (!chip->names) devprop_gpiochip_set_names(chip, of_fwnode_handle(chip->of_node)); of_node_get(chip->of_node); return of_gpiochip_scan_gpios(chip); } void of_gpiochip_remove(struct gpio_chip *chip) { gpiochip_remove_pin_ranges(chip); of_node_put(chip->of_node); }