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 --- a/drivers/gpio/Makefile
  19 +++ b/drivers/gpio/Makefile
  20 @@ -2,7 +2,7 @@
  21
  22  ccflags-$(CONFIG_DEBUG_GPIO)   += -DDEBUG
  23
  24 -obj-$(CONFIG_GPIOLIB)          += gpiolib.o
  25 +obj-$(CONFIG_GPIOLIB)          += gpiolib.o devres.o
  26
  27  # Device drivers. Generally keep list sorted alphabetically
  28  obj-$(CONFIG_GPIO_GENERIC)     += gpio-generic.o
  29 --- /dev/null
  30 +++ b/drivers/gpio/devres.c
  31 @@ -0,0 +1,90 @@
  32 +/*
  33 + * drivers/gpio/devres.c - managed gpio resources
  34 + *
  35 + * This program is free software; you can redistribute it and/or modify
  36 + * it under the terms of the GNU General Public License version 2
  37 + * as published by the Free Software Foundation.
  38 + *
  39 + * You should have received a copy of the GNU General Public License
  40 + * along with this program; if not, write to the Free Software
  41 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  42 + *
  43 + * This file is based on kernel/irq/devres.c
  44 + *
  45 + * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
  46 + */
  47 +
  48 +#include <linux/module.h>
  49 +#include <linux/gpio.h>
  50 +#include <linux/device.h>
  51 +#include <linux/gfp.h>
  52 +
  53 +static void devm_gpio_release(struct device *dev, void *res)
  54 +{
  55 +       unsigned *gpio = res;
  56 +
  57 +       gpio_free(*gpio);
  58 +}
  59 +
  60 +static int devm_gpio_match(struct device *dev, void *res, void *data)
  61 +{
  62 +       unsigned *this = res, *gpio = data;
  63 +
  64 +       return *this == *gpio;
  65 +}
  66 +
  67 +/**
  68 + *      devm_gpio_request - request a gpio for a managed device
  69 + *      @dev: device to request the gpio for
  70 + *      @gpio: gpio to allocate
  71 + *      @label: the name of the requested gpio
  72 + *
  73 + *      Except for the extra @dev argument, this function takes the
  74 + *      same arguments and performs the same function as
  75 + *      gpio_request().  GPIOs requested with this function will be
  76 + *      automatically freed on driver detach.
  77 + *
  78 + *      If an GPIO allocated with this function needs to be freed
  79 + *      separately, devm_gpio_free() must be used.
  80 + */
  81 +
  82 +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
  83 +{
  84 +       unsigned *dr;
  85 +       int rc;
  86 +
  87 +       dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
  88 +       if (!dr)
  89 +               return -ENOMEM;
  90 +
  91 +       rc = gpio_request(gpio, label);
  92 +       if (rc) {
  93 +               devres_free(dr);
  94 +               return rc;
  95 +       }
  96 +
  97 +       *dr = gpio;
  98 +       devres_add(dev, dr);
  99 +
 100 +       return 0;
 101 +}
 102 +EXPORT_SYMBOL(devm_gpio_request);
 103 +
 104 +/**
 105 + *      devm_gpio_free - free an interrupt
 106 + *      @dev: device to free gpio for
 107 + *      @gpio: gpio to free
 108 + *
 109 + *      Except for the extra @dev argument, this function takes the
 110 + *      same arguments and performs the same function as gpio_free().
 111 + *      This function instead of gpio_free() should be used to manually
 112 + *      free GPIOs allocated with devm_gpio_request().
 113 + */
 114 +void devm_gpio_free(struct device *dev, unsigned int gpio)
 115 +{
 116 +
 117 +       WARN_ON(devres_destroy(dev, devm_gpio_release, devm_gpio_match,
 118 +               &gpio));
 119 +       gpio_free(gpio);
 120 +}
 121 +EXPORT_SYMBOL(devm_gpio_free);
 122 --- a/include/asm-generic/gpio.h
 123 +++ b/include/asm-generic/gpio.h
 124 @@ -175,6 +175,10 @@ extern int gpio_request_one(unsigned gpi
 125  extern int gpio_request_array(const struct gpio *array, size_t num);
 126  extern void gpio_free_array(const struct gpio *array, size_t num);
 127
 128 +/* bindings for managed devices that want to request gpios */
 129 +int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
 130 +void devm_gpio_free(struct device *dev, unsigned int gpio);
 131 +
 132  #ifdef CONFIG_GPIO_SYSFS
 133
 134  /*