1 files changed, 280 insertions, 0 deletions

diff --git a/kernel/drivers/watchdog/sama5d4_wdt.c b/kernel/drivers/watchdog/sama5d4_wdt.c
new file mode 100644
index 000000000..a49634cdc
--- /dev/null
+++ b/kernel/drivers/watchdog/sama5d4_wdt.c
@@ -0,0 +1,280 @@
+/*
+ * Driver for Atmel SAMA5D4 Watchdog Timer
+ *
+ * Copyright (C) 2015 Atmel Corporation
+ *
+ * Licensed under GPLv2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#include "at91sam9_wdt.h"
+
+/* minimum and maximum watchdog timeout, in seconds */
+#define MIN_WDT_TIMEOUT		1
+#define MAX_WDT_TIMEOUT		16
+#define WDT_DEFAULT_TIMEOUT	MAX_WDT_TIMEOUT
+
+#define WDT_SEC2TICKS(s)	((s) ? (((s) << 8) - 1) : 0)
+
+struct sama5d4_wdt {
+	struct watchdog_device	wdd;
+	void __iomem		*reg_base;
+	u32	config;
+};
+
+static int wdt_timeout = WDT_DEFAULT_TIMEOUT;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+module_param(wdt_timeout, int, 0);
+MODULE_PARM_DESC(wdt_timeout,
+	"Watchdog timeout in seconds. (default = "
+	__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+	"Watchdog cannot be stopped once started (default="
+	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+#define wdt_read(wdt, field) \
+	readl_relaxed((wdt)->reg_base + (field))
+
+#define wdt_write(wtd, field, val) \
+	writel_relaxed((val), (wdt)->reg_base + (field))
+
+static int sama5d4_wdt_start(struct watchdog_device *wdd)
+{
+	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
+	u32 reg;
+
+	reg = wdt_read(wdt, AT91_WDT_MR);
+	reg &= ~AT91_WDT_WDDIS;
+	wdt_write(wdt, AT91_WDT_MR, reg);
+
+	return 0;
+}
+
+static int sama5d4_wdt_stop(struct watchdog_device *wdd)
+{
+	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
+	u32 reg;
+
+	reg = wdt_read(wdt, AT91_WDT_MR);
+	reg |= AT91_WDT_WDDIS;
+	wdt_write(wdt, AT91_WDT_MR, reg);
+
+	return 0;
+}
+
+static int sama5d4_wdt_ping(struct watchdog_device *wdd)
+{
+	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
+
+	return 0;
+}
+
+static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
+				 unsigned int timeout)
+{
+	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
+	u32 value = WDT_SEC2TICKS(timeout);
+	u32 reg;
+
+	reg = wdt_read(wdt, AT91_WDT_MR);
+	reg &= ~AT91_WDT_WDV;
+	reg &= ~AT91_WDT_WDD;
+	reg |= AT91_WDT_SET_WDV(value);
+	reg |= AT91_WDT_SET_WDD(value);
+	wdt_write(wdt, AT91_WDT_MR, reg);
+
+	wdd->timeout = timeout;
+
+	return 0;
+}
+
+static const struct watchdog_info sama5d4_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.identity = "Atmel SAMA5D4 Watchdog",
+};
+
+static struct watchdog_ops sama5d4_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = sama5d4_wdt_start,
+	.stop = sama5d4_wdt_stop,
+	.ping = sama5d4_wdt_ping,
+	.set_timeout = sama5d4_wdt_set_timeout,
+};
+
+static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
+{
+	struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
+
+	if (wdt_read(wdt, AT91_WDT_SR)) {
+		pr_crit("Atmel Watchdog Software Reset\n");
+		emergency_restart();
+		pr_crit("Reboot didn't succeed\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
+{
+	const char *tmp;
+
+	wdt->config = AT91_WDT_WDDIS;
+
+	if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
+	    !strcmp(tmp, "software"))
+		wdt->config |= AT91_WDT_WDFIEN;
+	else
+		wdt->config |= AT91_WDT_WDRSTEN;
+
+	if (of_property_read_bool(np, "atmel,idle-halt"))
+		wdt->config |= AT91_WDT_WDIDLEHLT;
+
+	if (of_property_read_bool(np, "atmel,dbg-halt"))
+		wdt->config |= AT91_WDT_WDDBGHLT;
+
+	return 0;
+}
+
+static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
+{
+	struct watchdog_device *wdd = &wdt->wdd;
+	u32 value = WDT_SEC2TICKS(wdd->timeout);
+	u32 reg;
+
+	/*
+	 * Because the fields WDV and WDD must not be modified when the WDDIS
+	 * bit is set, so clear the WDDIS bit before writing the WDT_MR.
+	 */
+	reg = wdt_read(wdt, AT91_WDT_MR);
+	reg &= ~AT91_WDT_WDDIS;
+	wdt_write(wdt, AT91_WDT_MR, reg);
+
+	reg = wdt->config;
+	reg |= AT91_WDT_SET_WDD(value);
+	reg |= AT91_WDT_SET_WDV(value);
+
+	wdt_write(wdt, AT91_WDT_MR, reg);
+
+	return 0;
+}
+
+static int sama5d4_wdt_probe(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd;
+	struct sama5d4_wdt *wdt;
+	struct resource *res;
+	void __iomem *regs;
+	u32 irq = 0;
+	int ret;
+
+	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	wdd = &wdt->wdd;
+	wdd->timeout = wdt_timeout;
+	wdd->info = &sama5d4_wdt_info;
+	wdd->ops = &sama5d4_wdt_ops;
+	wdd->min_timeout = MIN_WDT_TIMEOUT;
+	wdd->max_timeout = MAX_WDT_TIMEOUT;
+
+	watchdog_set_drvdata(wdd, wdt);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	wdt->reg_base = regs;
+
+	if (pdev->dev.of_node) {
+		irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+		if (!irq)
+			dev_warn(&pdev->dev, "failed to get IRQ from DT\n");
+
+		ret = of_sama5d4_wdt_init(pdev->dev.of_node, wdt);
+		if (ret)
+			return ret;
+	}
+
+	if ((wdt->config & AT91_WDT_WDFIEN) && irq) {
+		ret = devm_request_irq(&pdev->dev, irq, sama5d4_wdt_irq_handler,
+				       IRQF_SHARED | IRQF_IRQPOLL |
+				       IRQF_NO_SUSPEND, pdev->name, pdev);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"cannot register interrupt handler\n");
+			return ret;
+		}
+	}
+
+	ret = watchdog_init_timeout(wdd, wdt_timeout, &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to set timeout value\n");
+		return ret;
+	}
+
+	ret = sama5d4_wdt_init(wdt);
+	if (ret)
+		return ret;
+
+	watchdog_set_nowayout(wdd, nowayout);
+
+	ret = watchdog_register_device(wdd);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register watchdog device\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, wdt);
+
+	dev_info(&pdev->dev, "initialized (timeout = %d sec, nowayout = %d)\n",
+		 wdt_timeout, nowayout);
+
+	return 0;
+}
+
+static int sama5d4_wdt_remove(struct platform_device *pdev)
+{
+	struct sama5d4_wdt *wdt = platform_get_drvdata(pdev);
+
+	sama5d4_wdt_stop(&wdt->wdd);
+
+	watchdog_unregister_device(&wdt->wdd);
+
+	return 0;
+}
+
+static const struct of_device_id sama5d4_wdt_of_match[] = {
+	{ .compatible = "atmel,sama5d4-wdt", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
+
+static struct platform_driver sama5d4_wdt_driver = {
+	.probe		= sama5d4_wdt_probe,
+	.remove		= sama5d4_wdt_remove,
+	.driver		= {
+		.name	= "sama5d4_wdt",
+		.of_match_table = sama5d4_wdt_of_match,
+	}
+};
+module_platform_driver(sama5d4_wdt_driver);
+
+MODULE_AUTHOR("Atmel Corporation");
+MODULE_DESCRIPTION("Atmel SAMA5D4 Watchdog Timer driver");
+MODULE_LICENSE("GPL v2");