gpiolib: use gpio_chips list in gpiochip_find

Using the GPIO chips list is much faster than parsing the entire GPIO
number space.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c1d8f7b..5a79cb9 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1195,20 +1195,17 @@ struct gpio_chip *gpiochip_find(void *data,
                                int (*match)(struct gpio_chip *chip,
                                             void *data))
 {
-       struct gpio_chip *chip = NULL;
+       struct gpio_chip *chip;
        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;
+       list_for_each_entry(chip, &gpio_chips, list)
+               if (match(chip, data))
                        break;
-               }
-       }
+
+       /* No match? */
+       if (&chip->list == &gpio_chips)
+               chip = NULL;
        spin_unlock_irqrestore(&gpio_lock, flags);
 
        return chip;