diff options
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 713ca0e37f23..73fd328f6fe4 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1153,6 +1153,38 @@ int gpiochip_remove(struct gpio_chip *chip) } EXPORT_SYMBOL_GPL(gpiochip_remove); +/** + * gpiochip_find() - iterator for locating a specific gpio_chip + * @data: data to pass to match function + * @callback: Callback function to check gpio_chip + * + * Similar to bus_find_device. It returns a reference to a gpio_chip as + * determined by a user supplied @match callback. The callback should return + * 0 if the device doesn't match and non-zero if it does. If the callback is + * non-zero, this function will return to the caller and not iterate over any + * more gpio_chips. + */ +struct gpio_chip *gpiochip_find(void *data, + int (*match)(struct gpio_chip *chip, void *data)) +{ + struct gpio_chip *chip = NULL; + unsigned long flags; + int i; + + spin_lock_irqsave(&gpio_lock, flags); + for (i = 0; i < ARCH_NR_GPIOS; i++) { + if (!gpio_desc[i].chip) + continue; + + if (match(gpio_desc[i].chip, data)) { + chip = gpio_desc[i].chip; + break; + } + } + spin_unlock_irqrestore(&gpio_lock, flags); + + return chip; +} /* These "optional" allocation calls help prevent drivers from stomping * on each other, and help provide better diagnostics in debugfs. |