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>

1 files changed, 10 insertions, 27 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5a79cb955d9f..585d7c3ce12e 100644
--- 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;