target/linux/ramips/patches-3.10/0029-owrt-GPIO-add-gpio_export_with_name.patch

   1 From 8f3ed1fffa35d18c2b20ebb866c71a22cc0589ff Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 23 Jun 2013 00:16:22 +0200
   4 Subject: [PATCH 29/33] 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                       |   68 +++++++++++++++++++++++
  12  drivers/gpio/gpiolib.c                          |   24 +++++---
  13  include/asm-generic/gpio.h                      |    6 +-
  14  include/linux/gpio.h                            |   26 ++++++++-
  15  5 files changed, 172 insertions(+), 12 deletions(-)
  16
  17 diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
  18 index d933af3..c264748 100644
  19 --- a/Documentation/devicetree/bindings/gpio/gpio.txt
  20 +++ b/Documentation/devicetree/bindings/gpio/gpio.txt
  21 @@ -112,3 +112,63 @@ where,
  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 diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
  86 index 665f953..15ec5e5 100644
  87 --- a/drivers/gpio/gpiolib-of.c
  88 +++ b/drivers/gpio/gpiolib-of.c
  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 @@ -242,3 +244,69 @@ void of_gpiochip_remove(struct gpio_chip *chip)
  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 diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
 169 index c2534d6..8697c82 100644
 170 --- a/drivers/gpio/gpiolib.c
 171 +++ b/drivers/gpio/gpiolib.c
 172 @@ -96,7 +96,7 @@ static int gpiod_get_value(const struct gpio_desc *desc);
 173  static void gpiod_set_value(struct gpio_desc *desc, int value);
 174  static int gpiod_cansleep(const struct gpio_desc *desc);
 175  static int gpiod_to_irq(const struct gpio_desc *desc);
 176 -static int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
 177 +static int gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name);
 178  static int gpiod_export_link(struct device *dev, const char *name,
 179                              struct gpio_desc *desc);
 180  static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value);
 181 @@ -674,7 +674,7 @@ static ssize_t export_store(struct class *class,
 182                         status = -ENODEV;
 183                 goto done;
 184         }
 185 -       status = gpiod_export(desc, true);
 186 +       status = gpiod_export(desc, true, NULL);
 187         if (status < 0)
 188                 gpiod_free(desc);
 189         else
 190 @@ -736,9 +736,10 @@ static struct class gpio_class = {
 191
 192
 193  /**
 194 - * gpio_export - export a GPIO through sysfs
 195 + * gpio_export_with_name - export a GPIO through sysfs
 196   * @gpio: gpio to make available, already requested
 197   * @direction_may_change: true if userspace may change gpio direction
 198 + * @name: gpio name
 199   * Context: arch_initcall or later
 200   *
 201   * When drivers want to make a GPIO accessible to userspace after they
 202 @@ -750,7 +751,7 @@ static struct class gpio_class = {
 203   *
 204   * Returns zero on success, else an error.
 205   */
 206 -static int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
 207 +static int gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name)
 208  {
 209         unsigned long           flags;
 210         int                     status;
 211 @@ -783,6 +784,8 @@ static int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
 212                 goto fail_unlock;
 213         }
 214
 215 +       if (name)
 216 +               ioname = name;
 217         if (!desc->chip->direction_input || !desc->chip->direction_output)
 218                 direction_may_change = false;
 219         spin_unlock_irqrestore(&gpio_lock, flags);
 220 @@ -829,11 +832,11 @@ fail_unlock:
 221         return status;
 222  }
 223
 224 -int gpio_export(unsigned gpio, bool direction_may_change)
 225 +int gpio_export_with_name(unsigned gpio, bool direction_may_change, const char *name)
 226  {
 227 -       return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 228 +       return gpiod_export(gpio_to_desc(gpio), direction_may_change, name);
 229  }
 230 -EXPORT_SYMBOL_GPL(gpio_export);
 231 +EXPORT_SYMBOL_GPL(gpio_export_with_name);
 232
 233  static int match_export(struct device *dev, const void *data)
 234  {
 235 @@ -1092,7 +1095,7 @@ static inline void gpiochip_unexport(struct gpio_chip *chip)
 236  }
 237
 238  static inline int gpiod_export(struct gpio_desc *desc,
 239 -                              bool direction_may_change)
 240 +                              bool direction_may_change, const char *name)
 241  {
 242         return -ENOSYS;
 243  }
 244 @@ -1521,6 +1524,9 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
 245         if (flags & GPIOF_OPEN_SOURCE)
 246                 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
 247
 248 +       if (flags & GPIOF_ACTIVE_LOW)
 249 +               set_bit(FLAG_ACTIVE_LOW, &gpio_desc[gpio].flags);
 250 +
 251         if (flags & GPIOF_DIR_IN)
 252                 err = gpiod_direction_input(desc);
 253         else
 254 @@ -1531,7 +1537,7 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
 255                 goto free_gpio;
 256
 257         if (flags & GPIOF_EXPORT) {
 258 -               err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE);
 259 +               err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE, NULL);
 260                 if (err)
 261                         goto free_gpio;
 262         }
 263 diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
 264 index bde6469..3290572 100644
 265 --- a/include/asm-generic/gpio.h
 266 +++ b/include/asm-generic/gpio.h
 267 @@ -202,7 +202,8 @@ extern void gpio_free_array(const struct gpio *array, size_t num);
 268   * A sysfs interface can be exported by individual drivers if they want,
 269   * but more typically is configured entirely from userspace.
 270   */
 271 -extern int gpio_export(unsigned gpio, bool direction_may_change);
 272 +extern int gpio_export_with_name(unsigned gpio, bool direction_may_change,
 273 +                       const char *name);
 274  extern int gpio_export_link(struct device *dev, const char *name,
 275                         unsigned gpio);
 276  extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
 277 @@ -284,7 +285,8 @@ struct device;
 278
 279  /* sysfs support is only available with gpiolib, where it's optional */
 280
 281 -static inline int gpio_export(unsigned gpio, bool direction_may_change)
 282 +static inline int gpio_export_with_name(unsigned gpio,
 283 +       bool direction_may_change, const char *name)
 284  {
 285         return -ENOSYS;
 286  }
 287 diff --git a/include/linux/gpio.h b/include/linux/gpio.h
 288 index 552e3f4..07bbbcc7 100644
 289 --- a/include/linux/gpio.h
 290 +++ b/include/linux/gpio.h
 291 @@ -27,6 +27,9 @@
 292  #define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT)
 293  #define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
 294
 295 +#define GPIOF_ACTIVE_LOW       (1 << 6)
 296 +
 297 +
 298  /**
 299   * struct gpio - a structure describing a GPIO with configuration
 300   * @gpio:      the GPIO number
 301 @@ -169,7 +172,8 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value)
 302         WARN_ON(1);
 303  }
 304
 305 -static inline int gpio_export(unsigned gpio, bool direction_may_change)
 306 +static inline int gpio_export_with_name(unsigned gpio,
 307 +       bool direction_may_change, const char *name)
 308  {
 309         /* GPIO can never have been requested or set as {in,out}put */
 310         WARN_ON(1);
 311 @@ -236,4 +240,24 @@ int devm_gpio_request_one(struct device *dev, unsigned gpio,
 312                           unsigned long flags, const char *label);
 313  void devm_gpio_free(struct device *dev, unsigned int gpio);
 314
 315 +/**
 316 + * gpio_export - export a GPIO through sysfs
 317 + * @gpio: gpio to make available, already requested
 318 + * @direction_may_change: true if userspace may change gpio direction
 319 + * Context: arch_initcall or later
 320 + *
 321 + * When drivers want to make a GPIO accessible to userspace after they
 322 + * have requested it -- perhaps while debugging, or as part of their
 323 + * public interface -- they may use this routine.  If the GPIO can
 324 + * change direction (some can't) and the caller allows it, userspace
 325 + * will see "direction" sysfs attribute which may be used to change
 326 + * the gpio's direction.  A "value" attribute will always be provided.
 327 + *
 328 + * Returns zero on success, else an error.
 329 + */
 330 +static inline int gpio_export(unsigned gpio,bool direction_may_change)
 331 +{
 332 +       return gpio_export_with_name(gpio, direction_may_change, NULL);
 333 +}
 334 +
 335  #endif /* __LINUX_GPIO_H */
 336 --
 337 1.7.10.4
 338