target/linux/lantiq/patches-3.2/0001-GPIO-add-bindings-for-managed-devices.patch

   1 From 282f1ca84b35f3be68abc4fd8b52e229f3cb6bb7 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Thu, 8 Mar 2012 13:23:53 +0100
   4 Subject: [PATCH 01/70] GPIO: add bindings for managed devices
   5
   6 This patch adds 2 functions that allow managed devices to request GPIOs.
   7 These GPIOs will then be managed by drivers/base/devres.c.
   8
   9 Signed-off-by: John Crispin <blogic@openwrt.org>
  10 Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
  11 ---
  12  drivers/gpio/Makefile      |    2 +-
  13  drivers/gpio/devres.c      |   90 ++++++++++++++++++++++++++++++++++++++++++++
  14  include/asm-generic/gpio.h |    4 ++
  15  3 files changed, 95 insertions(+), 1 deletions(-)
  16  create mode 100644 drivers/gpio/devres.c
  17
  18 diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
  19 index 4e018d6..76dbd3f 100644
  20 --- a/drivers/gpio/Makefile
  21 +++ b/drivers/gpio/Makefile
  22 @@ -2,7 +2,7 @@
  23
  24  ccflags-$(CONFIG_DEBUG_GPIO)   += -DDEBUG
  25
  26 -obj-$(CONFIG_GPIOLIB)          += gpiolib.o
  27 +obj-$(CONFIG_GPIOLIB)          += gpiolib.o devres.o
  28
  29  # Device drivers. Generally keep list sorted alphabetically
  30  obj-$(CONFIG_GPIO_GENERIC)     += gpio-generic.o
  31 diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
  32 new file mode 100644
  33 index 0000000..3dd2939
  34 --- /dev/null
  35 +++ b/drivers/gpio/devres.c
  36 @@ -0,0 +1,90 @@
  37 +/*
  38 + * drivers/gpio/devres.c - managed gpio resources
  39 + *
  40 + * This program is free software; you can redistribute it and/or modify
  41 + * it under the terms of the GNU General Public License version 2
  42 + * as published by the Free Software Foundation.
  43 + *
  44 + * You should have received a copy of the GNU General Public License
  45 + * along with this program; if not, write to the Free Software
  46 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  47 + *
  48 + * This file is based on kernel/irq/devres.c
  49 + *
  50 + * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
  51 + */
  52 +
  53 +#include <linux/module.h>
  54 +#include <linux/gpio.h>
  55 +#include <linux/device.h>
  56 +#include <linux/gfp.h>
  57 +
  58 +static void devm_gpio_release(struct device *dev, void *res)
  59 +{
  60 +       unsigned *gpio = res;
  61 +
  62 +       gpio_free(*gpio);
  63 +}
  64 +
  65 +static int devm_gpio_match(struct device *dev, void *res, void *data)
  66 +{
  67 +       unsigned *this = res, *gpio = data;
  68 +
  69 +       return *this == *gpio;
  70 +}
  71 +
  72 +/**
  73 + *      devm_gpio_request - request a gpio for a managed device
  74 + *      @dev: device to request the gpio for
  75 + *      @gpio: gpio to allocate
  76 + *      @label: the name of the requested gpio
  77 + *
  78 + *      Except for the extra @dev argument, this function takes the
  79 + *      same arguments and performs the same function as
  80 + *      gpio_request().  GPIOs requested with this function will be
  81 + *      automatically freed on driver detach.
  82 + *
  83 + *      If an GPIO allocated with this function needs to be freed
  84 + *      separately, devm_gpio_free() must be used.
  85 + */
  86 +
  87 +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
  88 +{
  89 +       unsigned *dr;
  90 +       int rc;
  91 +
  92 +       dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
  93 +       if (!dr)
  94 +               return -ENOMEM;
  95 +
  96 +       rc = gpio_request(gpio, label);
  97 +       if (rc) {
  98 +               devres_free(dr);
  99 +               return rc;
 100 +       }
 101 +
 102 +       *dr = gpio;
 103 +       devres_add(dev, dr);
 104 +
 105 +       return 0;
 106 +}
 107 +EXPORT_SYMBOL(devm_gpio_request);
 108 +
 109 +/**
 110 + *      devm_gpio_free - free an interrupt
 111 + *      @dev: device to free gpio for
 112 + *      @gpio: gpio to free
 113 + *
 114 + *      Except for the extra @dev argument, this function takes the
 115 + *      same arguments and performs the same function as gpio_free().
 116 + *      This function instead of gpio_free() should be used to manually
 117 + *      free GPIOs allocated with devm_gpio_request().
 118 + */
 119 +void devm_gpio_free(struct device *dev, unsigned int gpio)
 120 +{
 121 +
 122 +       WARN_ON(devres_destroy(dev, devm_gpio_release, devm_gpio_match,
 123 +               &gpio));
 124 +       gpio_free(gpio);
 125 +}
 126 +EXPORT_SYMBOL(devm_gpio_free);
 127 diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
 128 index 8c86210..8601a02 100644
 129 --- a/include/asm-generic/gpio.h
 130 +++ b/include/asm-generic/gpio.h
 131 @@ -175,6 +175,10 @@ extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *labe
 132  extern int gpio_request_array(const struct gpio *array, size_t num);
 133  extern void gpio_free_array(const struct gpio *array, size_t num);
 134
 135 +/* bindings for managed devices that want to request gpios */
 136 +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
 137 +void devm_gpio_free(struct device *dev, unsigned int gpio);
 138 +
 139  #ifdef CONFIG_GPIO_SYSFS
 140
 141  /*
 142 --
 143 1.7.7.1
 144