This is a straight port from Linux v5.11.
Signed-off-by: Ahmad Fatoum <ahmad@xxxxxx>
---
drivers/watchdog/Kconfig | 7 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/gpio_wdt.c | 142 ++++++++++++++++++++++++++++++++++++
3 files changed, 150 insertions(+)
create mode 100644 drivers/watchdog/gpio_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 8750a97d8c50..fb4ea7ffac3c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -117,6 +117,13 @@ 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.
+
config ITCO_WDT
bool "Intel TCO Timer/Watchdog"
depends on X86
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index b55c58cf3cb3..9edb73512903 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_STM32_IWDG_WATCHDOG) += stm32_iwdg.o
obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o
obj-$(CONFIG_F71808E_WDT) += f71808e_wdt.o
obj-$(CONFIG_ITCO_WDT) += itco_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 000000000000..4de49dcee38a
--- /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@xxxxxxx>
+ */
+
+#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@xxxxxxx>");
+MODULE_DESCRIPTION("GPIO Watchdog");
+MODULE_LICENSE("GPL");
--
2.30.0
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