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>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c1d8f7bdcd8f..5a79cb955d9f 100644
--- 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;