Initial import

1 files changed, 239 insertions, 0 deletions

diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
new file mode 100644
index 000000000..cfdf8a408
--- /dev/null
+++ b/drivers/watchdog/davinci_wdt.c
@@ -0,0 +1,239 @@
+/*
+ * drivers/char/watchdog/davinci_wdt.c
+ *
+ * Watchdog driver for DaVinci DM644x/DM646x processors
+ *
+ * Copyright (C) 2006-2013 Texas Instruments.
+ *
+ * 2007 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#define MODULE_NAME "DAVINCI-WDT: "
+
+#define DEFAULT_HEARTBEAT 60
+#define MAX_HEARTBEAT     600	/* really the max margin is 264/27MHz*/
+
+/* Timer register set definition */
+#define PID12	(0x0)
+#define EMUMGT	(0x4)
+#define TIM12	(0x10)
+#define TIM34	(0x14)
+#define PRD12	(0x18)
+#define PRD34	(0x1C)
+#define TCR	(0x20)
+#define TGCR	(0x24)
+#define WDTCR	(0x28)
+
+/* TCR bit definitions */
+#define ENAMODE12_DISABLED	(0 << 6)
+#define ENAMODE12_ONESHOT	(1 << 6)
+#define ENAMODE12_PERIODIC	(2 << 6)
+
+/* TGCR bit definitions */
+#define TIM12RS_UNRESET		(1 << 0)
+#define TIM34RS_UNRESET		(1 << 1)
+#define TIMMODE_64BIT_WDOG      (2 << 2)
+
+/* WDTCR bit definitions */
+#define WDEN			(1 << 14)
+#define WDFLAG			(1 << 15)
+#define WDKEY_SEQ0		(0xa5c6 << 16)
+#define WDKEY_SEQ1		(0xda7e << 16)
+
+static int heartbeat;
+
+/*
+ * struct to hold data for each WDT device
+ * @base - base io address of WD device
+ * @clk - source clock of WDT
+ * @wdd - hold watchdog device as is in WDT core
+ */
+struct davinci_wdt_device {
+	void __iomem		*base;
+	struct clk		*clk;
+	struct watchdog_device	wdd;
+};
+
+static int davinci_wdt_start(struct watchdog_device *wdd)
+{
+	u32 tgcr;
+	u32 timer_margin;
+	unsigned long wdt_freq;
+	struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
+
+	wdt_freq = clk_get_rate(davinci_wdt->clk);
+
+	/* disable, internal clock source */
+	iowrite32(0, davinci_wdt->base + TCR);
+	/* reset timer, set mode to 64-bit watchdog, and unreset */
+	iowrite32(0, davinci_wdt->base + TGCR);
+	tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
+	iowrite32(tgcr, davinci_wdt->base + TGCR);
+	/* clear counter regs */
+	iowrite32(0, davinci_wdt->base + TIM12);
+	iowrite32(0, davinci_wdt->base + TIM34);
+	/* set timeout period */
+	timer_margin = (((u64)wdd->timeout * wdt_freq) & 0xffffffff);
+	iowrite32(timer_margin, davinci_wdt->base + PRD12);
+	timer_margin = (((u64)wdd->timeout * wdt_freq) >> 32);
+	iowrite32(timer_margin, davinci_wdt->base + PRD34);
+	/* enable run continuously */
+	iowrite32(ENAMODE12_PERIODIC, davinci_wdt->base + TCR);
+	/* Once the WDT is in pre-active state write to
+	 * TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are
+	 * write protected (except for the WDKEY field)
+	 */
+	/* put watchdog in pre-active state */
+	iowrite32(WDKEY_SEQ0 | WDEN, davinci_wdt->base + WDTCR);
+	/* put watchdog in active state */
+	iowrite32(WDKEY_SEQ1 | WDEN, davinci_wdt->base + WDTCR);
+	return 0;
+}
+
+static int davinci_wdt_ping(struct watchdog_device *wdd)
+{
+	struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
+
+	/* put watchdog in service state */
+	iowrite32(WDKEY_SEQ0, davinci_wdt->base + WDTCR);
+	/* put watchdog in active state */
+	iowrite32(WDKEY_SEQ1, davinci_wdt->base + WDTCR);
+	return 0;
+}
+
+static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+	u64 timer_counter;
+	unsigned long freq;
+	u32 val;
+	struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
+
+	/* if timeout has occured then return 0 */
+	val = ioread32(davinci_wdt->base + WDTCR);
+	if (val & WDFLAG)
+		return 0;
+
+	freq = clk_get_rate(davinci_wdt->clk);
+
+	if (!freq)
+		return 0;
+
+	timer_counter = ioread32(davinci_wdt->base + TIM12);
+	timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32);
+
+	do_div(timer_counter, freq);
+
+	return wdd->timeout - timer_counter;
+}
+
+static const struct watchdog_info davinci_wdt_info = {
+	.options = WDIOF_KEEPALIVEPING,
+	.identity = "DaVinci/Keystone Watchdog",
+};
+
+static const struct watchdog_ops davinci_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= davinci_wdt_start,
+	.stop		= davinci_wdt_ping,
+	.ping		= davinci_wdt_ping,
+	.get_timeleft	= davinci_wdt_get_timeleft,
+};
+
+static int davinci_wdt_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct device *dev = &pdev->dev;
+	struct resource  *wdt_mem;
+	struct watchdog_device *wdd;
+	struct davinci_wdt_device *davinci_wdt;
+
+	davinci_wdt = devm_kzalloc(dev, sizeof(*davinci_wdt), GFP_KERNEL);
+	if (!davinci_wdt)
+		return -ENOMEM;
+
+	davinci_wdt->clk = devm_clk_get(dev, NULL);
+	if (WARN_ON(IS_ERR(davinci_wdt->clk)))
+		return PTR_ERR(davinci_wdt->clk);
+
+	clk_prepare_enable(davinci_wdt->clk);
+
+	platform_set_drvdata(pdev, davinci_wdt);
+
+	wdd			= &davinci_wdt->wdd;
+	wdd->info		= &davinci_wdt_info;
+	wdd->ops		= &davinci_wdt_ops;
+	wdd->min_timeout	= 1;
+	wdd->max_timeout	= MAX_HEARTBEAT;
+	wdd->timeout		= DEFAULT_HEARTBEAT;
+
+	watchdog_init_timeout(wdd, heartbeat, dev);
+
+	dev_info(dev, "heartbeat %d sec\n", wdd->timeout);
+
+	watchdog_set_drvdata(wdd, davinci_wdt);
+	watchdog_set_nowayout(wdd, 1);
+
+	wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	davinci_wdt->base = devm_ioremap_resource(dev, wdt_mem);
+	if (IS_ERR(davinci_wdt->base))
+		return PTR_ERR(davinci_wdt->base);
+
+	ret = watchdog_register_device(wdd);
+	if (ret < 0)
+		dev_err(dev, "cannot register watchdog device\n");
+
+	return ret;
+}
+
+static int davinci_wdt_remove(struct platform_device *pdev)
+{
+	struct davinci_wdt_device *davinci_wdt = platform_get_drvdata(pdev);
+
+	watchdog_unregister_device(&davinci_wdt->wdd);
+	clk_disable_unprepare(davinci_wdt->clk);
+
+	return 0;
+}
+
+static const struct of_device_id davinci_wdt_of_match[] = {
+	{ .compatible = "ti,davinci-wdt", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, davinci_wdt_of_match);
+
+static struct platform_driver platform_wdt_driver = {
+	.driver = {
+		.name = "davinci-wdt",
+		.of_match_table = davinci_wdt_of_match,
+	},
+	.probe = davinci_wdt_probe,
+	.remove = davinci_wdt_remove,
+};
+
+module_platform_driver(platform_wdt_driver);
+
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("DaVinci Watchdog Driver");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+		 "Watchdog heartbeat period in seconds from 1 to "
+		 __MODULE_STRING(MAX_HEARTBEAT) ", default "
+		 __MODULE_STRING(DEFAULT_HEARTBEAT));
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:davinci-wdt");