gpiolib: use gpio_chips list in sysfs ops

This makes the code both simpler and faster compared to parsing the GPIO
number space.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5a79cb955d9f638aeb154476484b1bfcfd96ec96..585d7c3ce12ef9eade65c2faa6053c7584ba5b31 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1890,45 +1890,28 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
 {
        struct gpio_chip *chip = NULL;
-       unsigned int gpio;
-       void *ret = NULL;
-       loff_t index = 0;
+       loff_t index = *pos;
 
        /* REVISIT this isn't locked against gpio_chip removal ... */
 
-       for (gpio = 0; gpio_is_valid(gpio); gpio++) {
-               if (gpio_desc[gpio].chip == chip)
-                       continue;
-
-               chip = gpio_desc[gpio].chip;
-               if (!chip)
-                       continue;
-
-               if (index++ >= *pos) {
-                       ret = chip;
-                       break;
-               }
-       }
-
        s->private = "";
 
-       return ret;
+       list_for_each_entry(chip, &gpio_chips, list)
+               if (index-- == 0)
+                       return chip;
+
+       return NULL;
 }
 
 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
        struct gpio_chip *chip = v;
-       unsigned int gpio;
        void *ret = NULL;
 
-       /* skip GPIOs provided by the current chip */
-       for (gpio = chip->base + chip->ngpio; gpio_is_valid(gpio); gpio++) {
-               chip = gpio_desc[gpio].chip;
-               if (chip) {
-                       ret = chip;
-                       break;
-               }
-       }
+       if (list_is_last(&chip->list, &gpio_chips))
+               ret = NULL;
+       else
+               ret = list_entry(chip->list.next, struct gpio_chip, list);
 
        s->private = "\n";
        ++*pos;