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-3.8.11/Documentation/devicetree/bindings/gpio/gpio.txt
  18 ===================================================================
  19 --- linux-3.8.11.orig/Documentation/devicetree/bindings/gpio/gpio.txt   2013-05-01 18:56:10.000000000 +0200
  20 +++ linux-3.8.11/Documentation/devicetree/bindings/gpio/gpio.txt        2013-05-06 12:43:38.252652605 +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-3.8.11/drivers/gpio/gpiolib-of.c
  86 ===================================================================
  87 --- linux-3.8.11.orig/drivers/gpio/gpiolib-of.c 2013-05-01 18:56:10.000000000 +0200
  88 +++ linux-3.8.11/drivers/gpio/gpiolib-of.c      2013-05-06 13:35:56.452788709 +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 @@ -288,3 +290,69 @@
  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 +                       unsigned flags = 0;
 129 +                       enum of_gpio_flags of_flags;
 130 +
 131 +                       gpio = of_get_gpio_flags(cnp, i, &of_flags);
 132 +
 133 +                       if (of_flags == OF_GPIO_ACTIVE_LOW)
 134 +                               flags |= GPIOF_ACTIVE_LOW;
 135 +
 136 +                       if (!of_property_read_u32(cnp, "gpio-export,output", &val))
 137 +                               flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
 138 +                       else
 139 +                               flags |= GPIOF_IN;
 140 +
 141 +                       if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np)))
 142 +                               continue;
 143 +
 144 +                       dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change");
 145 +                       gpio_export_with_name(gpio, dmc, name);
 146 +                       nb++;
 147 +               }
 148 +       }
 149 +
 150 +       dev_info(&pdev->dev, "%d gpio(s) exported\n", nb);
 151 +
 152 +       return 0;
 153 +}
 154 +
 155 +static struct platform_driver gpio_export_driver = {
 156 +       .driver         = {
 157 +               .name           = "gpio-export",
 158 +               .owner  = THIS_MODULE,
 159 +               .of_match_table = of_match_ptr(gpio_export_ids),
 160 +       },
 161 +};
 162 +
 163 +static int __init of_gpio_export_init(void)
 164 +{
 165 +       return platform_driver_probe(&gpio_export_driver, of_gpio_export_probe);
 166 +}
 167 +device_initcall(of_gpio_export_init);
 168 Index: linux-3.8.11/drivers/gpio/gpiolib.c
 169 ===================================================================
 170 --- linux-3.8.11.orig/drivers/gpio/gpiolib.c    2013-05-01 18:56:10.000000000 +0200
 171 +++ linux-3.8.11/drivers/gpio/gpiolib.c 2013-05-06 13:31:35.060777376 +0200
 172 @@ -714,9 +714,10 @@
 173
 174
 175  /**
 176 - * gpio_export - export a GPIO through sysfs
 177 + * gpio_export_with_name - export a GPIO through sysfs
 178   * @gpio: gpio to make available, already requested
 179   * @direction_may_change: true if userspace may change gpio direction
 180 + * @name: gpio name
 181   * Context: arch_initcall or later
 182   *
 183   * When drivers want to make a GPIO accessible to userspace after they
 184 @@ -728,7 +729,7 @@
 185   *
 186   * Returns zero on success, else an error.
 187   */
 188 -int gpio_export(unsigned gpio, bool direction_may_change)
 189 +int gpio_export_with_name(unsigned gpio, bool direction_may_change, const char *name)
 190  {
 191         unsigned long           flags;
 192         struct gpio_desc        *desc;
 193 @@ -762,6 +763,8 @@
 194                 goto fail_unlock;
 195         }
 196
 197 +       if (name)
 198 +               ioname = name;
 199         if (!desc->chip->direction_input || !desc->chip->direction_output)
 200                 direction_may_change = false;
 201         spin_unlock_irqrestore(&gpio_lock, flags);
 202 @@ -804,7 +807,7 @@
 203         pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
 204         return status;
 205  }
 206 -EXPORT_SYMBOL_GPL(gpio_export);
 207 +EXPORT_SYMBOL_GPL(gpio_export_with_name);
 208
 209  static int match_export(struct device *dev, void *data)
 210  {
 211 @@ -1418,6 +1421,9 @@
 212         if (flags & GPIOF_OPEN_SOURCE)
 213                 set_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags);
 214
 215 +       if (flags & GPIOF_ACTIVE_LOW)
 216 +               set_bit(FLAG_ACTIVE_LOW, &gpio_desc[gpio].flags);
 217 +
 218         if (flags & GPIOF_DIR_IN)
 219                 err = gpio_direction_input(gpio);
 220         else
 221 Index: linux-3.8.11/include/asm-generic/gpio.h
 222 ===================================================================
 223 --- linux-3.8.11.orig/include/asm-generic/gpio.h        2013-05-01 18:56:10.000000000 +0200
 224 +++ linux-3.8.11/include/asm-generic/gpio.h     2013-05-06 12:43:38.252652605 +0200
 225 @@ -204,7 +204,8 @@
 226   * A sysfs interface can be exported by individual drivers if they want,
 227   * but more typically is configured entirely from userspace.
 228   */
 229 -extern int gpio_export(unsigned gpio, bool direction_may_change);
 230 +extern int gpio_export_with_name(unsigned gpio, bool direction_may_change,
 231 +                       const char *name);
 232  extern int gpio_export_link(struct device *dev, const char *name,
 233                         unsigned gpio);
 234  extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
 235 @@ -249,7 +250,8 @@
 236
 237  /* sysfs support is only available with gpiolib, where it's optional */
 238
 239 -static inline int gpio_export(unsigned gpio, bool direction_may_change)
 240 +static inline int gpio_export_with_name(unsigned gpio,
 241 +       bool direction_may_change, const char *name)
 242  {
 243         return -ENOSYS;
 244  }
 245 Index: linux-3.8.11/include/linux/gpio.h
 246 ===================================================================
 247 --- linux-3.8.11.orig/include/linux/gpio.h      2013-05-01 18:56:10.000000000 +0200
 248 +++ linux-3.8.11/include/linux/gpio.h   2013-05-06 13:32:59.796781050 +0200
 249 @@ -27,6 +27,9 @@
 250  #define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT)
 251  #define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
 252
 253 +#define GPIOF_ACTIVE_LOW       (1 << 6)
 254 +
 255 +
 256  /**
 257   * struct gpio - a structure describing a GPIO with configuration
 258   * @gpio:      the GPIO number
 259 @@ -189,7 +192,8 @@
 260         WARN_ON(1);
 261  }
 262
 263 -static inline int gpio_export(unsigned gpio, bool direction_may_change)
 264 +static inline int gpio_export_with_name(unsigned gpio,
 265 +       bool direction_may_change, const char *name)
 266  {
 267         /* GPIO can never have been requested or set as {in,out}put */
 268         WARN_ON(1);
 269 @@ -248,4 +252,24 @@
 270
 271  #endif /* ! CONFIG_GENERIC_GPIO */
 272
 273 +/**
 274 + * gpio_export - export a GPIO through sysfs
 275 + * @gpio: gpio to make available, already requested
 276 + * @direction_may_change: true if userspace may change gpio direction
 277 + * Context: arch_initcall or later
 278 + *
 279 + * When drivers want to make a GPIO accessible to userspace after they
 280 + * have requested it -- perhaps while debugging, or as part of their
 281 + * public interface -- they may use this routine.  If the GPIO can
 282 + * change direction (some can't) and the caller allows it, userspace
 283 + * will see "direction" sysfs attribute which may be used to change
 284 + * the gpio's direction.  A "value" attribute will always be provided.
 285 + *
 286 + * Returns zero on success, else an error.
 287 + */
 288 +static inline int gpio_export(unsigned gpio,bool direction_may_change)
 289 +{
 290 +       return gpio_export_with_name(gpio, direction_may_change, NULL);
 291 +}
 292 +
 293  #endif /* __LINUX_GPIO_H */