diff options
| -rw-r--r-- | drivers/gpio/Makefile | 2 | ||||
| -rw-r--r-- | drivers/gpio/devres.c | 90 | ||||
| -rw-r--r-- | include/asm-generic/gpio.h | 4 |
3 files changed, 95 insertions, 1 deletions
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 4e018d6a7639..76dbd3f55ef5 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -2,7 +2,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG -obj-$(CONFIG_GPIOLIB) += gpiolib.o +obj-$(CONFIG_GPIOLIB) += gpiolib.o devres.o # Device drivers. Generally keep list sorted alphabetically obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c new file mode 100644 index 000000000000..3dd29399cef5 --- /dev/null +++ b/drivers/gpio/devres.c @@ -0,0 +1,90 @@ +/* + * 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/gpio.h> +#include <linux/device.h> +#include <linux/gfp.h> + +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_free - free an interrupt + * @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_destroy(dev, devm_gpio_release, devm_gpio_match, + &gpio)); + gpio_free(gpio); +} +EXPORT_SYMBOL(devm_gpio_free); diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index d466c8d8826d..1ff4e221cb4d 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -177,6 +177,10 @@ extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *labe extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); +/* bindings for managed devices that want to request gpios */ +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label); +void devm_gpio_free(struct device *dev, unsigned int gpio); + #ifdef CONFIG_GPIO_SYSFS /* |