diff options
Diffstat (limited to 'drivers/gpio/devres.c')
| -rw-r--r-- | drivers/gpio/devres.c | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c new file mode 100644 index 000000000..07ba82317 --- /dev/null +++ b/drivers/gpio/devres.c @@ -0,0 +1,392 @@ +/* + * drivers/gpio/devres.c - managed gpio resources + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * This file is based on kernel/irq/devres.c + * + * Copyright (c) 2011 John Crispin <blogic@openwrt.org> + */ + +#include <linux/module.h> +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/gpio/consumer.h> +#include <linux/device.h> +#include <linux/gfp.h> + +static void devm_gpiod_release(struct device *dev, void *res) +{ + struct gpio_desc **desc = res; + + gpiod_put(*desc); +} + +static int devm_gpiod_match(struct device *dev, void *res, void *data) +{ + struct gpio_desc **this = res, **gpio = data; + + return *this == *gpio; +} + +static void devm_gpiod_release_array(struct device *dev, void *res) +{ + struct gpio_descs **descs = res; + + gpiod_put_array(*descs); +} + +static int devm_gpiod_match_array(struct device *dev, void *res, void *data) +{ + struct gpio_descs **this = res, **gpios = data; + + return *this == *gpios; +} + +/** + * devm_gpiod_get - Resource-managed gpiod_get() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get(). GPIO descriptors returned from this function are + * automatically disposed on driver detach. See gpiod_get() for detailed + * information about behavior and return values. + */ +struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev, + const char *con_id, + enum gpiod_flags flags) +{ + return devm_gpiod_get_index(dev, con_id, 0, flags); +} +EXPORT_SYMBOL(__devm_gpiod_get); + +/** + * devm_gpiod_get_optional - Resource-managed gpiod_get_optional() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get_optional(). GPIO descriptors returned from this function + * are automatically disposed on driver detach. See gpiod_get_optional() for + * detailed information about behavior and return values. + */ +struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) +{ + return devm_gpiod_get_index_optional(dev, con_id, 0, flags); +} +EXPORT_SYMBOL(__devm_gpiod_get_optional); + +/** + * devm_gpiod_get_index - Resource-managed gpiod_get_index() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @idx: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get_index(). GPIO descriptors returned from this function are + * automatically disposed on driver detach. See gpiod_get_index() for detailed + * information about behavior and return values. + */ +struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx, + enum gpiod_flags flags) +{ + struct gpio_desc **dr; + struct gpio_desc *desc; + + dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *), + GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + desc = gpiod_get_index(dev, con_id, idx, flags); + if (IS_ERR(desc)) { + devres_free(dr); + return desc; + } + + *dr = desc; + devres_add(dev, dr); + + return desc; +} +EXPORT_SYMBOL(__devm_gpiod_get_index); + +/** + * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @child: firmware node (child of @dev) + * + * GPIO descriptors returned from this function are automatically disposed on + * driver detach. + */ +struct gpio_desc *devm_get_gpiod_from_child(struct device *dev, + const char *con_id, + struct fwnode_handle *child) +{ + static const char * const suffixes[] = { "gpios", "gpio" }; + char prop_name[32]; /* 32 is max size of property name */ + struct gpio_desc **dr; + struct gpio_desc *desc; + unsigned int i; + + dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *), + GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < ARRAY_SIZE(suffixes); i++) { + if (con_id) + snprintf(prop_name, sizeof(prop_name), "%s-%s", + con_id, suffixes[i]); + else + snprintf(prop_name, sizeof(prop_name), "%s", + suffixes[i]); + + desc = fwnode_get_named_gpiod(child, prop_name); + if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER)) + break; + } + if (IS_ERR(desc)) { + devres_free(dr); + return desc; + } + + *dr = desc; + devres_add(dev, dr); + + return desc; +} +EXPORT_SYMBOL(devm_get_gpiod_from_child); + +/** + * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @index: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get_index_optional(). GPIO descriptors returned from this + * function are automatically disposed on driver detach. See + * gpiod_get_index_optional() for detailed information about behavior and + * return values. + */ +struct gpio_desc *__must_check __devm_gpiod_get_index_optional(struct device *dev, + const char *con_id, + unsigned int index, + enum gpiod_flags flags) +{ + struct gpio_desc *desc; + + desc = devm_gpiod_get_index(dev, con_id, index, flags); + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; +} +EXPORT_SYMBOL(__devm_gpiod_get_index_optional); + +/** + * devm_gpiod_get_array - Resource-managed gpiod_get_array() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get_array(). GPIO descriptors returned from this function are + * automatically disposed on driver detach. See gpiod_get_array() for detailed + * information about behavior and return values. + */ +struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags) +{ + struct gpio_descs **dr; + struct gpio_descs *descs; + + dr = devres_alloc(devm_gpiod_release_array, + sizeof(struct gpio_descs *), GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + descs = gpiod_get_array(dev, con_id, flags); + if (IS_ERR(descs)) { + devres_free(dr); + return descs; + } + + *dr = descs; + devres_add(dev, dr); + + return descs; +} +EXPORT_SYMBOL(devm_gpiod_get_array); + +/** + * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get_array_optional(). GPIO descriptors returned from this + * function are automatically disposed on driver detach. + * See gpiod_get_array_optional() for detailed information about behavior and + * return values. + */ +struct gpio_descs *__must_check +devm_gpiod_get_array_optional(struct device *dev, const char *con_id, + enum gpiod_flags flags) +{ + struct gpio_descs *descs; + + descs = devm_gpiod_get_array(dev, con_id, flags); + if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT)) + return NULL; + + return descs; +} +EXPORT_SYMBOL(devm_gpiod_get_array_optional); + +/** + * devm_gpiod_put - Resource-managed gpiod_put() + * @desc: GPIO descriptor to dispose of + * + * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or + * devm_gpiod_get_index(). Normally this function will not be called as the GPIO + * will be disposed of by the resource management code. + */ +void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) +{ + WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match, + &desc)); +} +EXPORT_SYMBOL(devm_gpiod_put); + +/** + * devm_gpiod_put_array - Resource-managed gpiod_put_array() + * @descs: GPIO descriptor array to dispose of + * + * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array(). + * Normally this function will not be called as the GPIOs will be disposed of + * by the resource management code. + */ +void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs) +{ + WARN_ON(devres_release(dev, devm_gpiod_release_array, + devm_gpiod_match_array, &descs)); +} +EXPORT_SYMBOL(devm_gpiod_put_array); + + + + +static void devm_gpio_release(struct device *dev, void *res) +{ + unsigned *gpio = res; + + gpio_free(*gpio); +} + +static int devm_gpio_match(struct device *dev, void *res, void *data) +{ + unsigned *this = res, *gpio = data; + + return *this == *gpio; +} + +/** + * devm_gpio_request - request a GPIO for a managed device + * @dev: device to request the GPIO for + * @gpio: GPIO to allocate + * @label: the name of the requested GPIO + * + * Except for the extra @dev argument, this function takes the + * same arguments and performs the same function as + * gpio_request(). GPIOs requested with this function will be + * automatically freed on driver detach. + * + * If an GPIO allocated with this function needs to be freed + * separately, devm_gpio_free() must be used. + */ + +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label) +{ + unsigned *dr; + int rc; + + dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + rc = gpio_request(gpio, label); + if (rc) { + devres_free(dr); + return rc; + } + + *dr = gpio; + devres_add(dev, dr); + + return 0; +} +EXPORT_SYMBOL(devm_gpio_request); + +/** + * devm_gpio_request_one - request a single GPIO with initial setup + * @dev: device to request for + * @gpio: the GPIO number + * @flags: GPIO configuration as specified by GPIOF_* + * @label: a literal description string of this GPIO + */ +int devm_gpio_request_one(struct device *dev, unsigned gpio, + unsigned long flags, const char *label) +{ + unsigned *dr; + int rc; + + dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + rc = gpio_request_one(gpio, flags, label); + if (rc) { + devres_free(dr); + return rc; + } + + *dr = gpio; + devres_add(dev, dr); + + return 0; +} +EXPORT_SYMBOL(devm_gpio_request_one); + +/** + * devm_gpio_free - free a GPIO + * @dev: device to free GPIO for + * @gpio: GPIO to free + * + * Except for the extra @dev argument, this function takes the + * same arguments and performs the same function as gpio_free(). + * This function instead of gpio_free() should be used to manually + * free GPIOs allocated with devm_gpio_request(). + */ +void devm_gpio_free(struct device *dev, unsigned int gpio) +{ + + WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match, + &gpio)); +} +EXPORT_SYMBOL(devm_gpio_free); |