On 10/2/24 21:23, Rasmus Villemoes wrote:
Back when I added this driver in commit 2ac8490412c9, I wroteThe 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 <[email protected]>
Reviewed-by: Stefan Roese <[email protected]> Thanks, Stefan
--- drivers/watchdog/gpio_wdt.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c index 2920c2c751f..e889861e917 100644 --- a/drivers/watchdog/gpio_wdt.c +++ b/drivers/watchdog/gpio_wdt.c @@ -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, };
Viele Grüße, Stefan Roese -- DENX Software Engineering GmbH, Managing Director: Erika Unter HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: [email protected]
