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watchdog: mtx1-wdt: fix GPIO toggling 

Commit e391be76 (MIPS: Alchemy: Clean up GPIO registers and accessors)
changed the way the GPIO was toggled. Prior to this patch, we would
always actively drive the GPIO output to either 0 or 1, this patch
drove the GPIO active to 0, and put the GPIO in tristate to drive it
to 1, unfortunately this does not work, revert back to active driving.

Using a signed variable (gstate) to hold the gpio state and using a bit-
wise operation on it also resulted in toggling value from 1 to -2 since
the variable is signed. This value was then passed on to gpio_direction_
output, which always perform a if (value) ... to set the value to the
gpio, so we were always writing a 1 to this GPIO instead of 1 -> 0 -> 1 ...

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: stable <stable@kernel.org>
hifive-unleashed-5.1
Florian Fainelli 2011-06-15 19:15:41 +02:00 committed by Wim Van Sebroeck
parent 9b19d40aa3
commit 2ea4e76e99
1 changed files with 5 additions and 8 deletions
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13
drivers/watchdog/mtx-1_wdt.c
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@ -66,7 +66,7 @@ static struct {
int default_ticks;
unsigned long inuse;
unsigned gpio;
int gstate;
unsigned int gstate;
} mtx1_wdt_device;
static void mtx1_wdt_trigger(unsigned long unused)
@ -78,11 +78,8 @@ static void mtx1_wdt_trigger(unsigned long unused)
ticks--;
/* toggle wdt gpio */
mtx1_wdt_device.gstate = ~mtx1_wdt_device.gstate;
if (mtx1_wdt_device.gstate)
gpio_direction_output(mtx1_wdt_device.gpio, 1);
else
gpio_direction_input(mtx1_wdt_device.gpio);
mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
if (mtx1_wdt_device.queue && ticks)
mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
@ -105,7 +102,7 @@ static void mtx1_wdt_start(void)
if (!mtx1_wdt_device.queue) {
mtx1_wdt_device.queue = 1;
mtx1_wdt_device.gstate = 1;
gpio_direction_output(mtx1_wdt_device.gpio, 1);
gpio_set_value(mtx1_wdt_device.gpio, 1);
mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
}
mtx1_wdt_device.running++;
@ -120,7 +117,7 @@ static int mtx1_wdt_stop(void)
if (mtx1_wdt_device.queue) {
mtx1_wdt_device.queue = 0;
mtx1_wdt_device.gstate = 0;
gpio_direction_output(mtx1_wdt_device.gpio, 0);
gpio_set_value(mtx1_wdt_device.gpio, 0);
}
ticks = mtx1_wdt_device.default_ticks;
spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);