diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/watchdog/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/gpio_wdt.c | 142 |
3 files changed, 150 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index cf83b6a15b..df85a227ac 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -117,4 +117,11 @@ config F71808E_WDT F71862FG, F71868, F71869, F71882FG, F71889FG, F81865 and F81866 Super I/O controllers. +config GPIO_WATCHDOG + tristate "Watchdog device controlled through GPIO-line" + depends on OF_GPIO + help + If you say yes here you get support for watchdog device + controlled through GPIO-line. + endif diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index dc9842770a..e88da0adaf 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -16,3 +16,4 @@ obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o obj-$(CONFIG_STM32_IWDG_WATCHDOG) += stm32_iwdg.o obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o obj-$(CONFIG_F71808E_WDT) += f71808e_wdt.o +obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c new file mode 100644 index 0000000000..4de49dcee3 --- /dev/null +++ b/drivers/watchdog/gpio_wdt.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for watchdog device controlled through GPIO-line + * + * Author: 2013, Alexander Shiyan <shc_work@mail.ru> + */ + +#include <common.h> +#include <driver.h> +#include <watchdog.h> +#include <superio.h> +#include <gpiod.h> + +enum { + HW_ALGO_TOGGLE, + HW_ALGO_LEVEL, +}; + +struct gpio_wdt_priv { + int gpio; + bool state; + bool started; + unsigned int hw_algo; + struct watchdog wdd; +}; + +static inline struct gpio_wdt_priv *to_gpio_wdt_priv(struct watchdog *wdd) +{ + return container_of(wdd, struct gpio_wdt_priv, wdd); +} + +static void gpio_wdt_disable(struct gpio_wdt_priv *priv) +{ + /* Eternal ping */ + gpio_set_active(priv->gpio, 1); + + /* Put GPIO back to tristate */ + if (priv->hw_algo == HW_ALGO_TOGGLE) + gpio_direction_input(priv->gpio); + + priv->started = false; +} + +static void gpio_wdt_ping(struct gpio_wdt_priv *priv) +{ + switch (priv->hw_algo) { + case HW_ALGO_TOGGLE: + /* Toggle output pin */ + priv->state = !priv->state; + gpio_set_active(priv->gpio, priv->state); + break; + case HW_ALGO_LEVEL: + /* Pulse */ + gpio_set_active(priv->gpio, true); + udelay(1); + gpio_set_active(priv->gpio, false); + break; + } +} + +static void gpio_wdt_start(struct gpio_wdt_priv *priv) +{ + priv->state = false; + gpio_direction_active(priv->gpio, priv->state); + priv->started = true; +} + +static int gpio_wdt_set_timeout(struct watchdog *wdd, unsigned int new_timeout) +{ + struct gpio_wdt_priv *priv = to_gpio_wdt_priv(wdd); + + if (!new_timeout) { + gpio_wdt_disable(priv); + return 0; + } + + if (!priv->started) + gpio_wdt_start(priv); + + gpio_wdt_ping(priv); + return 0; +} + +static int gpio_wdt_probe(struct device_d *dev) +{ + struct device_node *np = dev->device_node; + struct gpio_wdt_priv *priv; + enum gpiod_flags gflags; + unsigned int hw_margin; + const char *algo; + int ret; + + priv = xzalloc(sizeof(*priv)); + + ret = of_property_read_u32(np, "hw_margin_ms", &hw_margin); + if (ret) + return ret; + + /* Autoping is fixed at one ping every 500 ms. Round it up to a second */ + if (hw_margin < 1000) + return -EINVAL; + + ret = of_property_read_string(np, "hw_algo", &algo); + if (ret) + return ret; + if (!strcmp(algo, "toggle")) { + priv->hw_algo = HW_ALGO_TOGGLE; + gflags = GPIOD_IN; + } else if (!strcmp(algo, "level")) { + priv->hw_algo = HW_ALGO_LEVEL; + gflags = GPIOD_OUT_LOW; + } else { + return -EINVAL; + } + + priv->gpio = gpiod_get(dev, NULL, gflags); + if (priv->gpio < 0) + return priv->gpio; + + priv->wdd.hwdev = dev; + priv->wdd.timeout_max = hw_margin / 1000; + priv->wdd.priority = 129; + priv->wdd.set_timeout = gpio_wdt_set_timeout; + + return watchdog_register(&priv->wdd); +} + +static const struct of_device_id gpio_wdt_dt_ids[] = { + { .compatible = "linux,wdt-gpio", }, + { } +}; + +static struct driver_d gpio_wdt_driver = { + .name = "gpio-wdt", + .of_compatible = gpio_wdt_dt_ids, + .probe = gpio_wdt_probe, +}; +device_platform_driver(gpio_wdt_driver); + +MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); +MODULE_DESCRIPTION("GPIO Watchdog"); +MODULE_LICENSE("GPL"); |