target/linux/ramips/patches-3.8/0209-owrt-GPIO-add-gpio_export_with_name.patch

   1 From eda15425bcd2703ea1cfeebd65847305c17e5f0a Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Wed, 27 Mar 2013 18:38:48 +0100
   4 Subject: [PATCH] owrt: GPIO: add gpio_export_with_name
   5
   6 http://lists.infradead.org/pipermail/linux-arm-kernel/2012-November/133856.html
   7
   8 Signed-off-by: John Crispin <blogic@openwrt.org>
   9 ---
  10  Documentation/devicetree/bindings/gpio/gpio.txt |   60 ++++++++++++++++++++++
  11  drivers/gpio/gpiolib-of.c                       |   61 +++++++++++++++++++++++
  12  drivers/gpio/gpiolib.c                          |   18 +++++--
  13  include/asm-generic/gpio.h                      |    6 ++-
  14  include/linux/gpio.h                            |   23 ++++++++-
  15  5 files changed, 160 insertions(+), 8 deletions(-)
  16
  17 Index: linux-3.8.3/Documentation/devicetree/bindings/gpio/gpio.txt
  18 ===================================================================
  19 --- linux-3.8.3.orig/Documentation/devicetree/bindings/gpio/gpio.txt    2013-03-14 19:27:14.000000000 +0100
  20 +++ linux-3.8.3/Documentation/devicetree/bindings/gpio/gpio.txt 2013-04-01 11:11:42.151167467 +0200
  21 @@ -112,3 +112,63 @@
  22
  23  The pinctrl node must have "#gpio-range-cells" property to show number of
  24  arguments to pass with phandle from gpio controllers node.
  25 +
  26 +3) gpio-export
  27 +--------------
  28 +
  29 +gpio-export will allow you to automatically export gpio
  30 +
  31 +required properties:
  32 +- compatible: Should be "gpio-export"
  33 +
  34 +in each child node will reprensent a gpio or if no name is specified
  35 +a list of gpio to export
  36 +
  37 +required properties:
  38 +- gpios: gpio to export
  39 +
  40 +optional properties:
  41 + - gpio-export,name: export name
  42 + - gpio-export,output: to set the as output with default value
  43 +                      if no present gpio as input
  44 + - pio-export,direction_may_change: boolean to allow the direction to be controllable
  45 +
  46 +Example:
  47 +
  48 +
  49 +gpio_export {
  50 +       compatible = "gpio-export";
  51 +       #size-cells = <0>;
  52 +
  53 +       in {
  54 +               gpio-export,name = "in";
  55 +               gpios = <&pioC 20 0>;
  56 +       };
  57 +
  58 +       out {
  59 +               gpio-export,name = "out";
  60 +               gpio-export,output = <1>;
  61 +               gpio-export,direction_may_change;
  62 +               gpios = <&pioC 21 0>;
  63 +       };
  64 +
  65 +       in_out {
  66 +               gpio-export,name = "in_out";
  67 +               gpio-export,direction_may_change;
  68 +               gpios = <&pioC 21 0>;
  69 +       };
  70 +
  71 +       gpios_in {
  72 +               gpios = <&pioB 0 0
  73 +                        &pioB 3 0
  74 +                        &pioC 4 0>;
  75 +               gpio-export,direction_may_change;
  76 +       };
  77 +
  78 +       gpios_out {
  79 +               gpios = <&pioB 1 0
  80 +                        &pioB 2 0
  81 +                        &pioC 3 0>;
  82 +               gpio-export,output = <1>;
  83 +       };
  84 +};
  85 Index: linux-3.8.3/drivers/gpio/gpiolib-of.c
  86 ===================================================================
  87 --- linux-3.8.3.orig/drivers/gpio/gpiolib-of.c  2013-03-14 19:27:14.000000000 +0100
  88 +++ linux-3.8.3/drivers/gpio/gpiolib-of.c       2013-04-01 11:11:42.151167467 +0200
  89 @@ -21,6 +21,8 @@
  90  #include <linux/of_gpio.h>
  91  #include <linux/pinctrl/pinctrl.h>
  92  #include <linux/slab.h>
  93 +#include <linux/init.h>
  94 +#include <linux/platform_device.h>
  95
  96  /* Private data structure for of_gpiochip_find_and_xlate */
  97  struct gg_data {
  98 @@ -289,3 +291,62 @@
  99         if (chip->of_node)
 100                 of_node_put(chip->of_node);
 101  }
 102 +
 103 +static struct of_device_id gpio_export_ids[] = {
 104 +       { .compatible = "gpio-export" },
 105 +       { /* sentinel */ }
 106 +};
 107 +
 108 +static int __init of_gpio_export_probe(struct platform_device *pdev)
 109 +{
 110 +       struct device_node *np = pdev->dev.of_node;
 111 +       struct device_node *cnp;
 112 +       u32 val;
 113 +       int nb = 0;
 114 +
 115 +       for_each_child_of_node(np, cnp) {
 116 +               const char *name = NULL;
 117 +               int gpio;
 118 +               bool dmc;
 119 +               int max_gpio = 1;
 120 +               int i;
 121 +
 122 +               of_property_read_string(cnp, "gpio-export,name", &name);
 123 +
 124 +               if (!name)
 125 +                       max_gpio = of_gpio_count(cnp);
 126 +
 127 +               for (i = 0; i < max_gpio; i++) {
 128 +                       gpio = of_get_gpio(cnp, i);
 129 +                       if (devm_gpio_request(&pdev->dev, gpio, name ? name : of_node_full_name(np)))
 130 +                               continue;
 131 +
 132 +                       if (!of_property_read_u32(cnp, "gpio-export,output", &val))
 133 +                               gpio_direction_output(gpio, val);
 134 +                       else
 135 +                               gpio_direction_input(gpio);
 136 +
 137 +                       dmc = of_property_read_bool(np, "gpio-export,direction_may_change");
 138 +                       gpio_export_with_name(gpio, dmc, name);
 139 +                       nb++;
 140 +               }
 141 +       }
 142 +
 143 +       dev_info(&pdev->dev, "%d gpio(s) exported\n", nb);
 144 +
 145 +       return 0;
 146 +}
 147 +
 148 +static struct platform_driver gpio_export_driver = {
 149 +       .driver         = {
 150 +               .name           = "gpio-export",
 151 +               .owner  = THIS_MODULE,
 152 +               .of_match_table = of_match_ptr(gpio_export_ids),
 153 +       },
 154 +};
 155 +
 156 +static int __init of_gpio_export_init(void)
 157 +{
 158 +       return platform_driver_probe(&gpio_export_driver, of_gpio_export_probe);
 159 +}
 160 +device_initcall(of_gpio_export_init);
 161 Index: linux-3.8.3/drivers/gpio/gpiolib.c
 162 ===================================================================
 163 --- linux-3.8.3.orig/drivers/gpio/gpiolib.c     2013-03-14 19:27:14.000000000 +0100
 164 +++ linux-3.8.3/drivers/gpio/gpiolib.c  2013-04-01 11:12:29.263168590 +0200
 165 @@ -714,9 +714,10 @@
 166
 167
 168  /**
 169 - * gpio_export - export a GPIO through sysfs
 170 + * gpio_export_with_name - export a GPIO through sysfs
 171   * @gpio: gpio to make available, already requested
 172   * @direction_may_change: true if userspace may change gpio direction
 173 + * @name: gpio name
 174   * Context: arch_initcall or later
 175   *
 176   * When drivers want to make a GPIO accessible to userspace after they
 177 @@ -728,7 +729,7 @@
 178   *
 179   * Returns zero on success, else an error.
 180   */
 181 -int gpio_export(unsigned gpio, bool direction_may_change)
 182 +int gpio_export_with_name(unsigned gpio, bool direction_may_change, const char *name)
 183  {
 184         unsigned long           flags;
 185         struct gpio_desc        *desc;
 186 @@ -762,6 +763,8 @@
 187                 goto fail_unlock;
 188         }
 189
 190 +       if (name)
 191 +               ioname = name;
 192         if (!desc->chip->direction_input || !desc->chip->direction_output)
 193                 direction_may_change = false;
 194         spin_unlock_irqrestore(&gpio_lock, flags);
 195 @@ -804,7 +807,7 @@
 196         pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
 197         return status;
 198  }
 199 -EXPORT_SYMBOL_GPL(gpio_export);
 200 +EXPORT_SYMBOL_GPL(gpio_export_with_name);
 201
 202  static int match_export(struct device *dev, void *data)
 203  {
 204 Index: linux-3.8.3/include/asm-generic/gpio.h
 205 ===================================================================
 206 --- linux-3.8.3.orig/include/asm-generic/gpio.h 2013-03-14 19:27:14.000000000 +0100
 207 +++ linux-3.8.3/include/asm-generic/gpio.h      2013-04-01 11:11:42.155167467 +0200
 208 @@ -204,7 +204,8 @@
 209   * A sysfs interface can be exported by individual drivers if they want,
 210   * but more typically is configured entirely from userspace.
 211   */
 212 -extern int gpio_export(unsigned gpio, bool direction_may_change);
 213 +extern int gpio_export_with_name(unsigned gpio, bool direction_may_change,
 214 +                       const char *name);
 215  extern int gpio_export_link(struct device *dev, const char *name,
 216                         unsigned gpio);
 217  extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
 218 @@ -249,7 +250,8 @@
 219
 220  /* sysfs support is only available with gpiolib, where it's optional */
 221
 222 -static inline int gpio_export(unsigned gpio, bool direction_may_change)
 223 +static inline int gpio_export_with_name(unsigned gpio,
 224 +       bool direction_may_change, const char *name)
 225  {
 226         return -ENOSYS;
 227  }
 228 Index: linux-3.8.3/include/linux/gpio.h
 229 ===================================================================
 230 --- linux-3.8.3.orig/include/linux/gpio.h       2013-03-14 19:27:14.000000000 +0100
 231 +++ linux-3.8.3/include/linux/gpio.h    2013-04-01 11:11:42.159167467 +0200
 232 @@ -189,7 +189,8 @@
 233         WARN_ON(1);
 234  }
 235
 236 -static inline int gpio_export(unsigned gpio, bool direction_may_change)
 237 +static inline int gpio_export_with_name(unsigned gpio,
 238 +       bool direction_may_change, const char *name)
 239  {
 240         /* GPIO can never have been requested or set as {in,out}put */
 241         WARN_ON(1);
 242 @@ -248,4 +249,24 @@
 243
 244  #endif /* ! CONFIG_GENERIC_GPIO */
 245
 246 +/**
 247 + * gpio_export - export a GPIO through sysfs
 248 + * @gpio: gpio to make available, already requested
 249 + * @direction_may_change: true if userspace may change gpio direction
 250 + * Context: arch_initcall or later
 251 + *
 252 + * When drivers want to make a GPIO accessible to userspace after they
 253 + * have requested it -- perhaps while debugging, or as part of their
 254 + * public interface -- they may use this routine.  If the GPIO can
 255 + * change direction (some can't) and the caller allows it, userspace
 256 + * will see "direction" sysfs attribute which may be used to change
 257 + * the gpio's direction.  A "value" attribute will always be provided.
 258 + *
 259 + * Returns zero on success, else an error.
 260 + */
 261 +static inline int gpio_export(unsigned gpio,bool direction_may_change)
 262 +{
 263 +       return gpio_export_with_name(gpio, direction_may_change, NULL);
 264 +}
 265 +
 266  #endif /* __LINUX_GPIO_H */