1 files changed, 327 insertions, 0 deletions
diff --git a/drivers/watchdog/wm831x_wdt.c b/drivers/watchdog/wm831x_wdt.c
new file mode 100644
index 00000000..b1815c5e
--- /dev/null
+++ b/drivers/watchdog/wm831x_wdt.c
@@ -0,0 +1,327 @@
+/*
+ * Watchdog driver for the wm831x PMICs
+ *
+ * Copyright (C) 2009 Wolfson Microelectronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/uaccess.h>
+#include <linux/gpio.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/pdata.h>
+#include <linux/mfd/wm831x/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) ")");
+
+struct wm831x_wdt_drvdata {
+	struct watchdog_device wdt;
+	struct wm831x *wm831x;
+	struct mutex lock;
+	int update_gpio;
+	int update_state;
+};
+
+/* We can't use the sub-second values here but they're included
+ * for completeness.  */
+static struct {
+	unsigned int time;  /* Seconds */
+	u16 val;            /* WDOG_TO value */
+} wm831x_wdt_cfgs[] = {
+	{  1, 2 },
+	{  2, 3 },
+	{  4, 4 },
+	{  8, 5 },
+	{ 16, 6 },
+	{ 32, 7 },
+	{ 33, 7 },  /* Actually 32.768s so include both, others round down */
+};
+
+static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
+{
+	struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+	struct wm831x *wm831x = driver_data->wm831x;
+	int ret;
+
+	mutex_lock(&driver_data->lock);
+
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret == 0) {
+		ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
+				      WM831X_WDOG_ENA, WM831X_WDOG_ENA);
+		wm831x_reg_lock(wm831x);
+	} else {
+		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
+			ret);
+	}
+
+	mutex_unlock(&driver_data->lock);
+
+	return ret;
+}
+
+static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+	struct wm831x *wm831x = driver_data->wm831x;
+	int ret;
+
+	mutex_lock(&driver_data->lock);
+
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret == 0) {
+		ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
+				      WM831X_WDOG_ENA, 0);
+		wm831x_reg_lock(wm831x);
+	} else {
+		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
+			ret);
+	}
+
+	mutex_unlock(&driver_data->lock);
+
+	return ret;
+}
+
+static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
+{
+	struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+	struct wm831x *wm831x = driver_data->wm831x;
+	int ret;
+	u16 reg;
+
+	mutex_lock(&driver_data->lock);
+
+	if (driver_data->update_gpio) {
+		gpio_set_value_cansleep(driver_data->update_gpio,
+					driver_data->update_state);
+		driver_data->update_state = !driver_data->update_state;
+		ret = 0;
+		goto out;
+	}
+
+	reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
+
+	if (!(reg & WM831X_WDOG_RST_SRC)) {
+		dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	reg |= WM831X_WDOG_RESET;
+
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret == 0) {
+		ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
+		wm831x_reg_lock(wm831x);
+	} else {
+		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
+			ret);
+	}
+
+out:
+	mutex_unlock(&driver_data->lock);
+
+	return ret;
+}
+
+static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
+				  unsigned int timeout)
+{
+	struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+	struct wm831x *wm831x = driver_data->wm831x;
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
+		if (wm831x_wdt_cfgs[i].time == timeout)
+			break;
+	if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
+		return -EINVAL;
+
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret == 0) {
+		ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
+				      WM831X_WDOG_TO_MASK,
+				      wm831x_wdt_cfgs[i].val);
+		wm831x_reg_lock(wm831x);
+	} else {
+		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
+			ret);
+	}
+
+	wdt_dev->timeout = timeout;
+
+	return ret;
+}
+
+static const struct watchdog_info wm831x_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "WM831x Watchdog",
+};
+
+static const struct watchdog_ops wm831x_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = wm831x_wdt_start,
+	.stop = wm831x_wdt_stop,
+	.ping = wm831x_wdt_ping,
+	.set_timeout = wm831x_wdt_set_timeout,
+};
+
+static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
+{
+	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+	struct wm831x_pdata *chip_pdata;
+	struct wm831x_watchdog_pdata *pdata;
+	struct wm831x_wdt_drvdata *driver_data;
+	struct watchdog_device *wm831x_wdt;
+	int reg, ret, i;
+
+	ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
+			ret);
+		goto err;
+	}
+	reg = ret;
+
+	if (reg & WM831X_WDOG_DEBUG)
+		dev_warn(wm831x->dev, "Watchdog is paused\n");
+
+	driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
+				   GFP_KERNEL);
+	if (!driver_data) {
+		dev_err(wm831x->dev, "Unable to alloacate watchdog device\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_init(&driver_data->lock);
+	driver_data->wm831x = wm831x;
+
+	wm831x_wdt = &driver_data->wdt;
+
+	wm831x_wdt->info = &wm831x_wdt_info;
+	wm831x_wdt->ops = &wm831x_wdt_ops;
+	watchdog_set_nowayout(wm831x_wdt, nowayout);
+	watchdog_set_drvdata(wm831x_wdt, driver_data);
+
+	reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
+	reg &= WM831X_WDOG_TO_MASK;
+	for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
+		if (wm831x_wdt_cfgs[i].val == reg)
+			break;
+	if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
+		dev_warn(wm831x->dev,
+			 "Unknown watchdog timeout: %x\n", reg);
+	else
+		wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
+
+	/* Apply any configuration */
+	if (pdev->dev.parent->platform_data) {
+		chip_pdata = pdev->dev.parent->platform_data;
+		pdata = chip_pdata->watchdog;
+	} else {
+		pdata = NULL;
+	}
+
+	if (pdata) {
+		reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
+			 WM831X_WDOG_RST_SRC);
+
+		reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
+		reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
+		reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
+
+		if (pdata->update_gpio) {
+			ret = gpio_request(pdata->update_gpio,
+					   "Watchdog update");
+			if (ret < 0) {
+				dev_err(wm831x->dev,
+					"Failed to request update GPIO: %d\n",
+					ret);
+				goto err;
+			}
+
+			ret = gpio_direction_output(pdata->update_gpio, 0);
+			if (ret != 0) {
+				dev_err(wm831x->dev,
+					"gpio_direction_output returned: %d\n",
+					ret);
+				goto err_gpio;
+			}
+
+			driver_data->update_gpio = pdata->update_gpio;
+
+			/* Make sure the watchdog takes hardware updates */
+			reg |= WM831X_WDOG_RST_SRC;
+		}
+
+		ret = wm831x_reg_unlock(wm831x);
+		if (ret == 0) {
+			ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
+			wm831x_reg_lock(wm831x);
+		} else {
+			dev_err(wm831x->dev,
+				"Failed to unlock security key: %d\n", ret);
+			goto err_gpio;
+		}
+	}
+
+	ret = watchdog_register_device(&driver_data->wdt);
+	if (ret != 0) {
+		dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
+			ret);
+		goto err_gpio;
+	}
+
+	dev_set_drvdata(&pdev->dev, driver_data);
+
+	return 0;
+
+err_gpio:
+	if (driver_data->update_gpio)
+		gpio_free(driver_data->update_gpio);
+err:
+	return ret;
+}
+
+static int __devexit wm831x_wdt_remove(struct platform_device *pdev)
+{
+	struct wm831x_wdt_drvdata *driver_data = dev_get_drvdata(&pdev->dev);
+
+	watchdog_unregister_device(&driver_data->wdt);
+
+	if (driver_data->update_gpio)
+		gpio_free(driver_data->update_gpio);
+
+	return 0;
+}
+
+static struct platform_driver wm831x_wdt_driver = {
+	.probe = wm831x_wdt_probe,
+	.remove = __devexit_p(wm831x_wdt_remove),
+	.driver = {
+		.name = "wm831x-watchdog",
+	},
+};
+
+module_platform_driver(wm831x_wdt_driver);
+
+MODULE_AUTHOR("Mark Brown");
+MODULE_DESCRIPTION("WM831x Watchdog");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-watchdog");