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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 | /* * 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_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); |