[PATCH 4/9] gpiolib: use gpio_chips list in sysfs ops

From: Alexandre Courbot
Date: Sat Feb 02 2013 - 11:29:39 EST


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

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 37 ++++++++++---------------------------
1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 92f9ee4..e473ded 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1889,45 +1889,28 @@ 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;
--
1.8.1.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/