@@ -45,14 +45,32 @@ static int gpio_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
if (priv->always_running)
return 0;
- return -ENOSYS;
+ dm_gpio_set_dir_flags(&priv->gpio, GPIOD_IS_OUT);
+ gpio_wdt_reset(dev);
+
+ return 0;
+}
+
+static int gpio_wdt_stop(struct udevice *dev)
+{
+ struct gpio_wdt_priv *priv = dev_get_priv(dev);
+
+ if (priv->always_running)
+ return -EOPNOTSUPP;
+
+ if (priv->hw_algo == HW_ALGO_TOGGLE)
+ dm_gpio_set_dir_flags(&priv->gpio, GPIOD_IS_IN);
+ else
+ dm_gpio_set_value(&priv->gpio, 1);
+
+ return 0;
}
static int dm_probe(struct udevice *dev)
{
struct gpio_wdt_priv *priv = dev_get_priv(dev);
- int ret;
const char *algo = dev_read_string(dev, "hw_algo");
+ int ret, flags;
if (!algo)
return -EINVAL;
@@ -64,7 +82,9 @@ static int dm_probe(struct udevice *dev)
return -EINVAL;
priv->always_running = dev_read_bool(dev, "always-running");
- ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
+ flags = priv->always_running || priv->hw_algo == HW_ALGO_LEVEL ?
+ GPIOD_IS_OUT : GPIOD_IS_IN;
+ ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, flags);
if (ret < 0) {
dev_err(dev, "Request for wdt gpio failed: %d\n", ret);
return ret;
@@ -78,6 +98,7 @@ static int dm_probe(struct udevice *dev)
static const struct wdt_ops gpio_wdt_ops = {
.start = gpio_wdt_start,
+ .stop = gpio_wdt_stop,
.reset = gpio_wdt_reset,
};
Back when I added this driver in commit 2ac8490412c9, I wrote The corresponding linux driver apparently has support for some watchdog circuits which can be disabled by tri-stating the gpio, but I have never actually encountered such a chip in the wild; That has changed now; I have a board with just such a watchdog on my desk currently. Add support for that. - For a hw_algo="toggle" device, the gpio is requested as output if the always-running flag is set, otherwise as input. - The ->start() method is updated to change the direction to output when required (i.e. it is not always-running). - The ->stop() method is implemented, but of course reports failure if always-running. As I still haven't met any hw_algo="level" devices, I'm not entirely sure how they fit in, but I'm borrowing logic from the corresponding linux driver: - In ->probe(), such devices always request the gpio as GPIOD_IS_OUT. - In ->stop(), the linux driver has an "eternal ping" comment and sets the gpio to (logic) high. Signed-off-by: Rasmus Villemoes <ravi@prevas.dk> --- drivers/watchdog/gpio_wdt.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-)