target/linux/generic/patches-3.3/070-gpio-add-flags-to-export-GPIOs-when-requesting.patch

   1 From fc3a1f04f5040255cbc086c419e4237f29f89f88 Mon Sep 17 00:00:00 2001
   2 From: Wolfram Sang <w.sang@pengutronix.de>
   3 Date: Tue, 13 Dec 2011 18:34:01 +0100
   4 Subject: [PATCH] gpio: add flags to export GPIOs when requesting
   5
   6 commit fc3a1f04f5040255cbc086c419e4237f29f89f88 upstream.
   7
   8 Introduce new flags to automatically export GPIOs when using the convenience
   9 functions gpio_request_one() or gpio_request_array(). This eases support for
  10 custom boards where lots of GPIOs need to be exported for customer
  11 applications.
  12
  13 Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
  14 Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
  15 ---
  16  Documentation/gpio.txt |    3 +++
  17  drivers/gpio/gpiolib.c |   12 +++++++++++-
  18  include/linux/gpio.h   |    5 +++++
  19  3 files changed, 19 insertions(+), 1 deletion(-)
  20
  21 --- a/Documentation/gpio.txt
  22 +++ b/Documentation/gpio.txt
  23 @@ -303,6 +303,9 @@ where 'flags' is currently defined to sp
  24         * GPIOF_INIT_LOW        - as output, set initial level to LOW
  25         * GPIOF_INIT_HIGH       - as output, set initial level to HIGH
  26
  27 +       * GPIOF_EXPORT_DIR_FIXED        - export gpio to sysfs, keep direction
  28 +       * GPIOF_EXPORT_DIR_CHANGEABLE   - also export, allow changing direction
  29 +
  30  since GPIOF_INIT_* are only valid when configured as output, so group valid
  31  combinations as:
  32
  33 --- a/drivers/gpio/gpiolib.c
  34 +++ b/drivers/gpio/gpiolib.c
  35 @@ -1289,8 +1289,18 @@ int gpio_request_one(unsigned gpio, unsi
  36                                 (flags & GPIOF_INIT_HIGH) ? 1 : 0);
  37
  38         if (err)
  39 -               gpio_free(gpio);
  40 +               goto free_gpio;
  41
  42 +       if (flags & GPIOF_EXPORT) {
  43 +               err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE);
  44 +               if (err)
  45 +                       goto free_gpio;
  46 +       }
  47 +
  48 +       return 0;
  49 +
  50 + free_gpio:
  51 +       gpio_free(gpio);
  52         return err;
  53  }
  54  EXPORT_SYMBOL_GPL(gpio_request_one);
  55 --- a/include/linux/gpio.h
  56 +++ b/include/linux/gpio.h
  57 @@ -14,6 +14,11 @@
  58  #define GPIOF_OUT_INIT_LOW     (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
  59  #define GPIOF_OUT_INIT_HIGH    (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
  60
  61 +#define GPIOF_EXPORT           (1 << 2)
  62 +#define GPIOF_EXPORT_CHANGEABLE        (1 << 3)
  63 +#define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT)
  64 +#define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
  65 +
  66  /**
  67   * struct gpio - a structure describing a GPIO with configuration
  68   * @gpio:      the GPIO number