// SPDX-License-Identifier: GPL-2.0+ /* * OF helpers for the GPIO API * * Copyright (c) 2007-2008 MontaVista Software, Inc. * * Author: Anton Vorontsov <[email protected]> */ #include <linux/device.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/io.h> #include <linux/module.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/string.h> #include <linux/gpio/consumer.h> #include <linux/gpio/machine.h> #include "gpiolib.h" #include "gpiolib-of.h" /* * This is Linux-specific flags. By default controllers' and Linux' mapping * match, but GPIO controllers are free to translate their own flags to * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. */ enum of_gpio_flags { … }; /** * of_gpio_named_count() - Count GPIOs for a device * @np: device node to count GPIOs for * @propname: property name containing gpio specifier(s) * * The function returns the count of GPIOs specified for a node. * Note that the empty GPIO specifiers count too. Returns either * Number of gpios defined in property, * -EINVAL for an incorrectly formed gpios property, or * -ENOENT for a missing gpios property * * Example: * gpios = <0 * &gpio1 1 2 * 0 * &gpio2 3 4>; * * The above example defines four GPIOs, two of which are not specified. * This function will return '4' */ static int of_gpio_named_count(const struct device_node *np, const char *propname) { … } /** * of_gpio_spi_cs_get_count() - special GPIO counting for SPI * @np: Consuming device node * @con_id: Function within the GPIO consumer * * Some elder GPIO controllers need special quirks. Currently we handle * the Freescale and PPC GPIO controller with bindings that doesn't use the * established "cs-gpios" for chip selects but instead rely on * "gpios" for the chip select lines. If we detect this, we redirect * the counting of "cs-gpios" to count "gpios" transparent to the * driver. */ static int of_gpio_spi_cs_get_count(const struct device_node *np, const char *con_id) { … } int of_gpio_count(const struct fwnode_handle *fwnode, const char *con_id) { … } static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, const void *data) { … } static struct gpio_device * of_find_gpio_device_by_xlate(const struct of_phandle_args *gpiospec) { … } static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, struct of_phandle_args *gpiospec, enum of_gpio_flags *flags) { … } /* * Overrides stated polarity of a gpio line and warns when there is a * discrepancy. */ static void of_gpio_quirk_polarity(const struct device_node *np, bool active_high, enum of_gpio_flags *flags) { … } /* * This quirk does static polarity overrides in cases where existing * DTS specified incorrect polarity. */ static void of_gpio_try_fixup_polarity(const struct device_node *np, const char *propname, enum of_gpio_flags *flags) { … } static void of_gpio_set_polarity_by_property(const struct device_node *np, const char *propname, enum of_gpio_flags *flags) { … } static void of_gpio_flags_quirks(const struct device_node *np, const char *propname, enum of_gpio_flags *flags, int index) { … } /** * 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. */ static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np, const char *propname, int index, enum of_gpio_flags *flags) { … } /** * of_get_named_gpio() - Get a GPIO number to use with GPIO API * @np: device node to get GPIO from * @propname: Name of property containing gpio specifier(s) * @index: index of the GPIO * * **DEPRECATED** This function is deprecated and must not be used in new code. * * Returns GPIO number to use with Linux generic GPIO API, or one of the errno * value on the error condition. */ int of_get_named_gpio(const struct device_node *np, const char *propname, int index) { … } EXPORT_SYMBOL_GPL(…); /* Converts gpio_lookup_flags into bitmask of GPIO_* values */ static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags) { … } static struct gpio_desc *of_find_gpio_rename(struct device_node *np, const char *con_id, unsigned int idx, enum of_gpio_flags *of_flags) { … } static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np, const char *con_id, unsigned int idx, enum of_gpio_flags *of_flags) { … } /* * Trigger sources are special, they allow us to use any GPIO as a LED trigger * and have the name "trigger-sources" no matter which kind of phandle it is * pointing to, whether to a GPIO, a USB host, a network PHY etc. So in this case * we allow looking something up that is not named "foo-gpios". */ static struct gpio_desc *of_find_trigger_gpio(struct device_node *np, const char *con_id, unsigned int idx, enum of_gpio_flags *of_flags) { … } of_find_gpio_quirk; static const of_find_gpio_quirk of_find_gpio_quirks[] = …; struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id, unsigned int idx, unsigned long *flags) { … } /** * 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: bitmask of gpio_lookup_flags GPIO_* values - 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, unsigned long *lflags, enum gpiod_flags *dflags) { … } /** * of_gpiochip_add_hog - Add all hogs in a hog device node * @chip: gpio chip to act on * @hog: device node describing the hogs * * Returns error if it fails otherwise 0 on success. */ static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog) { … } /** * 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) { … } #ifdef CONFIG_OF_DYNAMIC /** * of_gpiochip_remove_hog - Remove all hogs in a hog device node * @chip: gpio chip to act on * @hog: device node describing the hogs */ static void of_gpiochip_remove_hog(struct gpio_chip *chip, struct device_node *hog) { … } static int of_gpiochip_match_node(struct gpio_chip *chip, const void *data) { … } static struct gpio_device *of_find_gpio_device_by_node(struct device_node *np) { … } static int of_gpio_notify(struct notifier_block *nb, unsigned long action, void *arg) { … } struct notifier_block gpio_of_notifier = …; #endif /* CONFIG_OF_DYNAMIC */ /** * 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). */ static int of_gpio_simple_xlate(struct gpio_chip *gc, const struct of_phandle_args *gpiospec, u32 *flags) { … } #if IS_ENABLED(CONFIG_OF_GPIO_MM_GPIOCHIP) #include <linux/gpio/legacy-of-mm-gpiochip.h> /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); #endif #ifdef CONFIG_PINCTRL static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { … } #else static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } #endif int of_gpiochip_add(struct gpio_chip *chip) { … } void of_gpiochip_remove(struct gpio_chip *chip) { … }
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