1 files changed, 300 insertions, 0 deletions
diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
new file mode 100644
index 000000000..c6c736569
--- /dev/null
+++ b/drivers/watchdog/sunxi_wdt.c
@@ -0,0 +1,300 @@
+/*
+ *      sunxi Watchdog Driver
+ *
+ *      Copyright (c) 2013 Carlo Caione
+ *                    2012 Henrik Nordstrom
+ *
+ *      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; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ *      Based on xen_wdt.c
+ *      (c) Copyright 2010 Novell, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define WDT_MAX_TIMEOUT         16
+#define WDT_MIN_TIMEOUT         1
+#define WDT_TIMEOUT_MASK        0x0F
+
+#define WDT_CTRL_RELOAD         ((1 << 0) | (0x0a57 << 1))
+
+#define WDT_MODE_EN             (1 << 0)
+
+#define DRV_NAME		"sunxi-wdt"
+#define DRV_VERSION		"1.0"
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout;
+
+/*
+ * This structure stores the register offsets for different variants
+ * of Allwinner's watchdog hardware.
+ */
+struct sunxi_wdt_reg {
+	u8 wdt_ctrl;
+	u8 wdt_cfg;
+	u8 wdt_mode;
+	u8 wdt_timeout_shift;
+	u8 wdt_reset_mask;
+	u8 wdt_reset_val;
+};
+
+struct sunxi_wdt_dev {
+	struct watchdog_device wdt_dev;
+	void __iomem *wdt_base;
+	const struct sunxi_wdt_reg *wdt_regs;
+};
+
+/*
+ * wdt_timeout_map maps the watchdog timer interval value in seconds to
+ * the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3
+ *
+ * [timeout seconds] = register value
+ *
+ */
+
+static const int wdt_timeout_map[] = {
+	[1] = 0x1,  /* 1s  */
+	[2] = 0x2,  /* 2s  */
+	[3] = 0x3,  /* 3s  */
+	[4] = 0x4,  /* 4s  */
+	[5] = 0x5,  /* 5s  */
+	[6] = 0x6,  /* 6s  */
+	[8] = 0x7,  /* 8s  */
+	[10] = 0x8, /* 10s */
+	[12] = 0x9, /* 12s */
+	[14] = 0xA, /* 14s */
+	[16] = 0xB, /* 16s */
+};
+
+
+static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
+			     unsigned long action, void *data)
+{
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+	u32 val;
+
+	/* Set system reset function */
+	val = readl(wdt_base + regs->wdt_cfg);
+	val &= ~(regs->wdt_reset_mask);
+	val |= regs->wdt_reset_val;
+	writel(val, wdt_base + regs->wdt_cfg);
+
+	/* Set lowest timeout and enable watchdog */
+	val = readl(wdt_base + regs->wdt_mode);
+	val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
+	val |= WDT_MODE_EN;
+	writel(val, wdt_base + regs->wdt_mode);
+
+	/*
+	 * Restart the watchdog. The default (and lowest) interval
+	 * value for the watchdog is 0.5s.
+	 */
+	writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
+
+	while (1) {
+		mdelay(5);
+		val = readl(wdt_base + regs->wdt_mode);
+		val |= WDT_MODE_EN;
+		writel(val, wdt_base + regs->wdt_mode);
+	}
+	return 0;
+}
+
+static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
+{
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+
+	writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
+
+	return 0;
+}
+
+static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
+		unsigned int timeout)
+{
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+	u32 reg;
+
+	if (wdt_timeout_map[timeout] == 0)
+		timeout++;
+
+	sunxi_wdt->wdt_dev.timeout = timeout;
+
+	reg = readl(wdt_base + regs->wdt_mode);
+	reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
+	reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
+	writel(reg, wdt_base + regs->wdt_mode);
+
+	sunxi_wdt_ping(wdt_dev);
+
+	return 0;
+}
+
+static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+
+	writel(0, wdt_base + regs->wdt_mode);
+
+	return 0;
+}
+
+static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
+{
+	u32 reg;
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+	int ret;
+
+	ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
+			sunxi_wdt->wdt_dev.timeout);
+	if (ret < 0)
+		return ret;
+
+	/* Set system reset function */
+	reg = readl(wdt_base + regs->wdt_cfg);
+	reg &= ~(regs->wdt_reset_mask);
+	reg |= regs->wdt_reset_val;
+	writel(reg, wdt_base + regs->wdt_cfg);
+
+	/* Enable watchdog */
+	reg = readl(wdt_base + regs->wdt_mode);
+	reg |= WDT_MODE_EN;
+	writel(reg, wdt_base + regs->wdt_mode);
+
+	return 0;
+}
+
+static const struct watchdog_info sunxi_wdt_info = {
+	.identity	= DRV_NAME,
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops sunxi_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= sunxi_wdt_start,
+	.stop		= sunxi_wdt_stop,
+	.ping		= sunxi_wdt_ping,
+	.set_timeout	= sunxi_wdt_set_timeout,
+	.restart	= sunxi_wdt_restart,
+};
+
+static const struct sunxi_wdt_reg sun4i_wdt_reg = {
+	.wdt_ctrl = 0x00,
+	.wdt_cfg = 0x04,
+	.wdt_mode = 0x04,
+	.wdt_timeout_shift = 3,
+	.wdt_reset_mask = 0x02,
+	.wdt_reset_val = 0x02,
+};
+
+static const struct sunxi_wdt_reg sun6i_wdt_reg = {
+	.wdt_ctrl = 0x10,
+	.wdt_cfg = 0x14,
+	.wdt_mode = 0x18,
+	.wdt_timeout_shift = 4,
+	.wdt_reset_mask = 0x03,
+	.wdt_reset_val = 0x01,
+};
+
+static const struct of_device_id sunxi_wdt_dt_ids[] = {
+	{ .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
+	{ .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
+
+static int sunxi_wdt_probe(struct platform_device *pdev)
+{
+	struct sunxi_wdt_dev *sunxi_wdt;
+	struct resource *res;
+	int err;
+
+	sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
+	if (!sunxi_wdt)
+		return -EINVAL;
+
+	sunxi_wdt->wdt_regs = of_device_get_match_data(&pdev->dev);
+	if (!sunxi_wdt->wdt_regs)
+		return -ENODEV;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(sunxi_wdt->wdt_base))
+		return PTR_ERR(sunxi_wdt->wdt_base);
+
+	sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
+	sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
+	sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
+	sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
+	sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
+	sunxi_wdt->wdt_dev.parent = &pdev->dev;
+
+	watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
+	watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&sunxi_wdt->wdt_dev, 128);
+
+	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
+
+	sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
+
+	watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
+	err = devm_watchdog_register_device(&pdev->dev, &sunxi_wdt->wdt_dev);
+	if (unlikely(err))
+		return err;
+
+	dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
+			sunxi_wdt->wdt_dev.timeout, nowayout);
+
+	return 0;
+}
+
+static struct platform_driver sunxi_wdt_driver = {
+	.probe		= sunxi_wdt_probe,
+	.driver		= {
+		.name		= DRV_NAME,
+		.of_match_table	= sunxi_wdt_dt_ids,
+	},
+};
+
+module_platform_driver(sunxi_wdt_driver);
+
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+		"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
+MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
+MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);