git.openwrt.org Git - openwrt/staging/linusw.git/blob

   1 From 0cf3292cde22f8843ae5d1eeb8466d8121243c1a Mon Sep 17 00:00:00 2001
   2 From: Laxman Dewangan <ldewangan@nvidia.com>
   3 Date: Mon, 15 Feb 2016 16:32:09 +0530
   4 Subject: [PATCH] gpio: Add devm_ apis for gpiochip_add_data and
   5  gpiochip_remove
   6
   7 Add device managed APIs devm_gpiochip_add_data() and
   8 devm_gpiochip_remove() for the APIs gpiochip_add_data()
   9 and gpiochip_remove().
  10
  11 This helps in reducing code in error path and sometimes
  12 removal of .remove callback for driver unbind.
  13
  14 Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
  15 ---
  16  drivers/gpio/gpiolib.c      | 74 +++++++++++++++++++++++++++++++++++++++++++++
  17  include/linux/gpio/driver.h |  4 +++
  18  2 files changed, 78 insertions(+)
  19
  20 --- a/drivers/gpio/gpiolib.c
  21 +++ b/drivers/gpio/gpiolib.c
  22 @@ -433,6 +433,80 @@ void gpiochip_remove(struct gpio_chip *c
  23  }
  24  EXPORT_SYMBOL_GPL(gpiochip_remove);
  25
  26 +static void devm_gpio_chip_release(struct device *dev, void *res)
  27 +{
  28 +       struct gpio_chip *chip = *(struct gpio_chip **)res;
  29 +
  30 +       gpiochip_remove(chip);
  31 +}
  32 +
  33 +static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
  34 +
  35 +{
  36 +       struct gpio_chip **r = res;
  37 +
  38 +       if (!r || !*r) {
  39 +               WARN_ON(!r || !*r);
  40 +               return 0;
  41 +       }
  42 +
  43 +       return *r == data;
  44 +}
  45 +
  46 +/**
  47 + * devm_gpiochip_add_data() - Resource manager piochip_add_data()
  48 + * @dev: the device pointer on which irq_chip belongs to.
  49 + * @chip: the chip to register, with chip->base initialized
  50 + * Context: potentially before irqs will work
  51 + *
  52 + * Returns a negative errno if the chip can't be registered, such as
  53 + * because the chip->base is invalid or already associated with a
  54 + * different chip.  Otherwise it returns zero as a success code.
  55 + *
  56 + * The gpio chip automatically be released when the device is unbound.
  57 + */
  58 +int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
  59 +                          void *data)
  60 +{
  61 +       struct gpio_chip **ptr;
  62 +       int ret;
  63 +
  64 +       ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
  65 +                            GFP_KERNEL);
  66 +       if (!ptr)
  67 +               return -ENOMEM;
  68 +
  69 +       ret = gpiochip_add_data(chip, data);
  70 +       if (ret < 0) {
  71 +               devres_free(ptr);
  72 +               return ret;
  73 +       }
  74 +
  75 +       *ptr = chip;
  76 +       devres_add(dev, ptr);
  77 +
  78 +       return 0;
  79 +}
  80 +EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
  81 +
  82 +/**
  83 + * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
  84 + * @dev: device for which which resource was allocated
  85 + * @chip: the chip to remove
  86 + *
  87 + * A gpio_chip with any GPIOs still requested may not be removed.
  88 + */
  89 +void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
  90 +{
  91 +       int ret;
  92 +
  93 +       ret = devres_release(dev, devm_gpio_chip_release,
  94 +                            devm_gpio_chip_match, chip);
  95 +       if (!ret)
  96 +               WARN_ON(ret);
  97 +}
  98 +EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
  99 +
 100  /**
 101   * gpiochip_find() - iterator for locating a specific gpio_chip
 102   * @data: data to pass to match function
 103 --- a/include/linux/gpio/driver.h
 104 +++ b/include/linux/gpio/driver.h
 105 @@ -206,6 +206,10 @@ static inline int gpiochip_add(struct gp
 106         return gpiochip_add_data(chip, NULL);
 107  }
 108  extern void gpiochip_remove(struct gpio_chip *chip);
 109 +extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
 110 +                                 void *data);
 111 +extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
 112 +
 113  extern struct gpio_chip *gpiochip_find(void *data,
 114                               int (*match)(struct gpio_chip *chip, void *data));
 115