Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
new file mode 100644
index 000000000..0923201ce
--- /dev/null
+++ b/drivers/watchdog/gpio_wdt.c
@@ -0,0 +1,196 @@
+// 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 <linux/err.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+		"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+#define SOFT_TIMEOUT_MIN	1
+#define SOFT_TIMEOUT_DEF	60
+
+enum {
+	HW_ALGO_TOGGLE,
+	HW_ALGO_LEVEL,
+};
+
+struct gpio_wdt_priv {
+	struct gpio_desc	*gpiod;
+	bool			state;
+	bool			always_running;
+	unsigned int		hw_algo;
+	struct watchdog_device	wdd;
+};
+
+static void gpio_wdt_disable(struct gpio_wdt_priv *priv)
+{
+	/* Eternal ping */
+	gpiod_set_value_cansleep(priv->gpiod, 1);
+
+	/* Put GPIO back to tristate */
+	if (priv->hw_algo == HW_ALGO_TOGGLE)
+		gpiod_direction_input(priv->gpiod);
+}
+
+static int gpio_wdt_ping(struct watchdog_device *wdd)
+{
+	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	switch (priv->hw_algo) {
+	case HW_ALGO_TOGGLE:
+		/* Toggle output pin */
+		priv->state = !priv->state;
+		gpiod_set_value_cansleep(priv->gpiod, priv->state);
+		break;
+	case HW_ALGO_LEVEL:
+		/* Pulse */
+		gpiod_set_value_cansleep(priv->gpiod, 1);
+		udelay(1);
+		gpiod_set_value_cansleep(priv->gpiod, 0);
+		break;
+	}
+	return 0;
+}
+
+static int gpio_wdt_start(struct watchdog_device *wdd)
+{
+	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	priv->state = 0;
+	gpiod_direction_output(priv->gpiod, priv->state);
+
+	set_bit(WDOG_HW_RUNNING, &wdd->status);
+
+	return gpio_wdt_ping(wdd);
+}
+
+static int gpio_wdt_stop(struct watchdog_device *wdd)
+{
+	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	if (!priv->always_running) {
+		gpio_wdt_disable(priv);
+	} else {
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+	}
+
+	return 0;
+}
+
+static const struct watchdog_info gpio_wdt_ident = {
+	.options	= WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
+			  WDIOF_SETTIMEOUT,
+	.identity	= "GPIO Watchdog",
+};
+
+static const struct watchdog_ops gpio_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= gpio_wdt_start,
+	.stop		= gpio_wdt_stop,
+	.ping		= gpio_wdt_ping,
+};
+
+static int gpio_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct gpio_wdt_priv *priv;
+	enum gpiod_flags gflags;
+	unsigned int hw_margin;
+	const char *algo;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	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->gpiod = devm_gpiod_get(dev, NULL, gflags);
+	if (IS_ERR(priv->gpiod))
+		return PTR_ERR(priv->gpiod);
+
+	ret = of_property_read_u32(np,
+				   "hw_margin_ms", &hw_margin);
+	if (ret)
+		return ret;
+	/* Disallow values lower than 2 and higher than 65535 ms */
+	if (hw_margin < 2 || hw_margin > 65535)
+		return -EINVAL;
+
+	priv->always_running = of_property_read_bool(np,
+						     "always-running");
+
+	watchdog_set_drvdata(&priv->wdd, priv);
+
+	priv->wdd.info		= &gpio_wdt_ident;
+	priv->wdd.ops		= &gpio_wdt_ops;
+	priv->wdd.min_timeout	= SOFT_TIMEOUT_MIN;
+	priv->wdd.max_hw_heartbeat_ms = hw_margin;
+	priv->wdd.parent	= dev;
+	priv->wdd.timeout	= SOFT_TIMEOUT_DEF;
+
+	watchdog_init_timeout(&priv->wdd, 0, dev);
+	watchdog_set_nowayout(&priv->wdd, nowayout);
+
+	watchdog_stop_on_reboot(&priv->wdd);
+
+	if (priv->always_running)
+		gpio_wdt_start(&priv->wdd);
+
+	return devm_watchdog_register_device(dev, &priv->wdd);
+}
+
+static const struct of_device_id gpio_wdt_dt_ids[] = {
+	{ .compatible = "linux,wdt-gpio", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gpio_wdt_dt_ids);
+
+static struct platform_driver gpio_wdt_driver = {
+	.driver	= {
+		.name		= "gpio-wdt",
+		.of_match_table	= gpio_wdt_dt_ids,
+	},
+	.probe	= gpio_wdt_probe,
+};
+
+#ifdef CONFIG_GPIO_WATCHDOG_ARCH_INITCALL
+static int __init gpio_wdt_init(void)
+{
+	return platform_driver_register(&gpio_wdt_driver);
+}
+arch_initcall(gpio_wdt_init);
+#else
+module_platform_driver(gpio_wdt_driver);
+#endif
+
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("GPIO Watchdog");
+MODULE_LICENSE("GPL");