From 7f3d53c8bf3b851837dc2f5dd85e0c6a0d0116a1 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Wed, 2 Oct 2024 21:23:23 +0200 Subject: [PATCH] watchdog: gpio_wdt: add support for stoppable devices 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. Stefan: Added necessary changes in test/dm/wdt.c to fix CI build breakage, as suggested by Rasmus. Signed-off-by: Rasmus Villemoes Reviewed-by: Stefan Roese --- drivers/watchdog/gpio_wdt.c | 27 ++++++++++++++++++++++++--- test/dm/wdt.c | 4 ++-- 2 files changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c index 2920c2c751..e889861e91 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, }; diff --git a/test/dm/wdt.c b/test/dm/wdt.c index 541bcba1b5..710414881f 100644 --- a/test/dm/wdt.c +++ b/test/dm/wdt.c @@ -71,7 +71,7 @@ static int dm_test_wdt_gpio_toggle(struct unit_test_state *uts) ut_assertok(wdt_reset(wdt)); ut_asserteq(val, sandbox_gpio_get_value(gpio, offset)); - ut_asserteq(-ENOSYS, wdt_stop(wdt)); + ut_asserteq(-EOPNOTSUPP, wdt_stop(wdt)); return 0; } @@ -103,7 +103,7 @@ static int dm_test_wdt_gpio_level(struct unit_test_state *uts) ut_assertok(wdt_reset(wdt)); ut_asserteq(val, sandbox_gpio_get_value(gpio, offset)); - ut_asserteq(-ENOSYS, wdt_stop(wdt)); + ut_asserteq(-EOPNOTSUPP, wdt_stop(wdt)); return 0; } -- 2.39.5