1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
new file mode 100644
index 000000000..442c5bf63
--- /dev/null
+++ b/drivers/watchdog/ftwdt010_wdt.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Watchdog driver for Faraday Technology FTWDT010
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Inspired by the out-of-tree drivers from OpenWRT:
+ * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ */
+
+#include <linux/bitops.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/watchdog.h>
+
+#define FTWDT010_WDCOUNTER	0x0
+#define FTWDT010_WDLOAD		0x4
+#define FTWDT010_WDRESTART	0x8
+#define FTWDT010_WDCR		0xC
+
+#define WDRESTART_MAGIC		0x5AB9
+
+#define WDCR_CLOCK_5MHZ		BIT(4)
+#define WDCR_WDEXT		BIT(3)
+#define WDCR_WDINTR		BIT(2)
+#define WDCR_SYS_RST		BIT(1)
+#define WDCR_ENABLE		BIT(0)
+
+#define WDT_CLOCK		5000000		/* 5 MHz */
+
+struct ftwdt010_wdt {
+	struct watchdog_device	wdd;
+	struct device		*dev;
+	void __iomem		*base;
+	bool			has_irq;
+};
+
+static inline
+struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd)
+{
+	return container_of(wdd, struct ftwdt010_wdt, wdd);
+}
+
+static void ftwdt010_enable(struct ftwdt010_wdt *gwdt,
+			    unsigned int timeout,
+			    bool need_irq)
+{
+	u32 enable;
+
+	writel(timeout * WDT_CLOCK, gwdt->base + FTWDT010_WDLOAD);
+	writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
+	/* set clock before enabling */
+	enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST;
+	writel(enable, gwdt->base + FTWDT010_WDCR);
+	if (need_irq)
+		enable |= WDCR_WDINTR;
+	enable |= WDCR_ENABLE;
+	writel(enable, gwdt->base + FTWDT010_WDCR);
+}
+
+static int ftwdt010_wdt_start(struct watchdog_device *wdd)
+{
+	struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
+
+	ftwdt010_enable(gwdt, wdd->timeout, gwdt->has_irq);
+	return 0;
+}
+
+static int ftwdt010_wdt_stop(struct watchdog_device *wdd)
+{
+	struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
+
+	writel(0, gwdt->base + FTWDT010_WDCR);
+
+	return 0;
+}
+
+static int ftwdt010_wdt_ping(struct watchdog_device *wdd)
+{
+	struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
+
+	writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
+
+	return 0;
+}
+
+static int ftwdt010_wdt_set_timeout(struct watchdog_device *wdd,
+				  unsigned int timeout)
+{
+	wdd->timeout = timeout;
+	if (watchdog_active(wdd))
+		ftwdt010_wdt_start(wdd);
+
+	return 0;
+}
+
+static int ftwdt010_wdt_restart(struct watchdog_device *wdd,
+				unsigned long action, void *data)
+{
+	ftwdt010_enable(to_ftwdt010_wdt(wdd), 0, false);
+	return 0;
+}
+
+static irqreturn_t ftwdt010_wdt_interrupt(int irq, void *data)
+{
+	struct ftwdt010_wdt *gwdt = data;
+
+	watchdog_notify_pretimeout(&gwdt->wdd);
+
+	return IRQ_HANDLED;
+}
+
+static const struct watchdog_ops ftwdt010_wdt_ops = {
+	.start		= ftwdt010_wdt_start,
+	.stop		= ftwdt010_wdt_stop,
+	.ping		= ftwdt010_wdt_ping,
+	.set_timeout	= ftwdt010_wdt_set_timeout,
+	.restart	= ftwdt010_wdt_restart,
+	.owner		= THIS_MODULE,
+};
+
+static const struct watchdog_info ftwdt010_wdt_info = {
+	.options	= WDIOF_KEEPALIVEPING
+			| WDIOF_MAGICCLOSE
+			| WDIOF_SETTIMEOUT,
+	.identity	= KBUILD_MODNAME,
+};
+
+
+static int ftwdt010_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ftwdt010_wdt *gwdt;
+	unsigned int reg;
+	int irq;
+	int ret;
+
+	gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
+	if (!gwdt)
+		return -ENOMEM;
+
+	gwdt->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(gwdt->base))
+		return PTR_ERR(gwdt->base);
+
+	gwdt->dev = dev;
+	gwdt->wdd.info = &ftwdt010_wdt_info;
+	gwdt->wdd.ops = &ftwdt010_wdt_ops;
+	gwdt->wdd.min_timeout = 1;
+	gwdt->wdd.max_timeout = 0xFFFFFFFF / WDT_CLOCK;
+	gwdt->wdd.parent = dev;
+
+	/*
+	 * If 'timeout-sec' unspecified in devicetree, assume a 13 second
+	 * default.
+	 */
+	gwdt->wdd.timeout = 13U;
+	watchdog_init_timeout(&gwdt->wdd, 0, dev);
+
+	reg = readw(gwdt->base + FTWDT010_WDCR);
+	if (reg & WDCR_ENABLE) {
+		/* Watchdog was enabled by the bootloader, disable it. */
+		reg &= ~WDCR_ENABLE;
+		writel(reg, gwdt->base + FTWDT010_WDCR);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq > 0) {
+		ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
+				       "watchdog bark", gwdt);
+		if (ret)
+			return ret;
+		gwdt->has_irq = true;
+	}
+
+	ret = devm_watchdog_register_device(dev, &gwdt->wdd);
+	if (ret)
+		return ret;
+
+	/* Set up platform driver data */
+	platform_set_drvdata(pdev, gwdt);
+	dev_info(dev, "FTWDT010 watchdog driver enabled\n");
+
+	return 0;
+}
+
+static int __maybe_unused ftwdt010_wdt_suspend(struct device *dev)
+{
+	struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
+	unsigned int reg;
+
+	reg = readw(gwdt->base + FTWDT010_WDCR);
+	reg &= ~WDCR_ENABLE;
+	writel(reg, gwdt->base + FTWDT010_WDCR);
+
+	return 0;
+}
+
+static int __maybe_unused ftwdt010_wdt_resume(struct device *dev)
+{
+	struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
+	unsigned int reg;
+
+	if (watchdog_active(&gwdt->wdd)) {
+		reg = readw(gwdt->base + FTWDT010_WDCR);
+		reg |= WDCR_ENABLE;
+		writel(reg, gwdt->base + FTWDT010_WDCR);
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops ftwdt010_wdt_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ftwdt010_wdt_suspend,
+				ftwdt010_wdt_resume)
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id ftwdt010_wdt_match[] = {
+	{ .compatible = "faraday,ftwdt010" },
+	{ .compatible = "cortina,gemini-watchdog" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ftwdt010_wdt_match);
+#endif
+
+static struct platform_driver ftwdt010_wdt_driver = {
+	.probe		= ftwdt010_wdt_probe,
+	.driver		= {
+		.name	= "ftwdt010-wdt",
+		.of_match_table = of_match_ptr(ftwdt010_wdt_match),
+		.pm = &ftwdt010_wdt_dev_pm_ops,
+	},
+};
+module_platform_driver(ftwdt010_wdt_driver);
+MODULE_AUTHOR("Linus Walleij");
+MODULE_DESCRIPTION("Watchdog driver for Faraday Technology FTWDT010");
+MODULE_LICENSE("GPL");