From: Alexandre Courbot <acourbot@nvidia.com>
Date: Sat, 2 Feb 2013 16:29:26 +0000 (+0900)
Subject: gpiolib: use gpio_chips list in gpiochip_find
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=125eef96f6cfadddbac8f6b9fccc9848988e7c6e;p=linux-beck.git

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 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;