1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/watchdog/digicolor_wdt.c b/drivers/watchdog/digicolor_wdt.c
new file mode 100644
index 000000000..073d37867
--- /dev/null
+++ b/drivers/watchdog/digicolor_wdt.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Watchdog driver for Conexant Digicolor
+ *
+ * Copyright (C) 2015 Paradox Innovation Ltd.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+
+#define TIMER_A_CONTROL		0
+#define TIMER_A_COUNT		4
+
+#define TIMER_A_ENABLE_COUNT	BIT(0)
+#define TIMER_A_ENABLE_WATCHDOG	BIT(1)
+
+struct dc_wdt {
+	void __iomem		*base;
+	struct clk		*clk;
+	spinlock_t		lock;
+};
+
+static unsigned timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
+
+static void dc_wdt_set(struct dc_wdt *wdt, u32 ticks)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&wdt->lock, flags);
+
+	writel_relaxed(0, wdt->base + TIMER_A_CONTROL);
+	writel_relaxed(ticks, wdt->base + TIMER_A_COUNT);
+	writel_relaxed(TIMER_A_ENABLE_COUNT | TIMER_A_ENABLE_WATCHDOG,
+		       wdt->base + TIMER_A_CONTROL);
+
+	spin_unlock_irqrestore(&wdt->lock, flags);
+}
+
+static int dc_wdt_restart(struct watchdog_device *wdog, unsigned long action,
+			  void *data)
+{
+	struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
+
+	dc_wdt_set(wdt, 1);
+	/* wait for reset to assert... */
+	mdelay(500);
+
+	return 0;
+}
+
+static int dc_wdt_start(struct watchdog_device *wdog)
+{
+	struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
+
+	dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk));
+
+	return 0;
+}
+
+static int dc_wdt_stop(struct watchdog_device *wdog)
+{
+	struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
+
+	writel_relaxed(0, wdt->base + TIMER_A_CONTROL);
+
+	return 0;
+}
+
+static int dc_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t)
+{
+	struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
+
+	dc_wdt_set(wdt, t * clk_get_rate(wdt->clk));
+	wdog->timeout = t;
+
+	return 0;
+}
+
+static unsigned int dc_wdt_get_timeleft(struct watchdog_device *wdog)
+{
+	struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
+	uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT);
+
+	return count / clk_get_rate(wdt->clk);
+}
+
+static const struct watchdog_ops dc_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= dc_wdt_start,
+	.stop		= dc_wdt_stop,
+	.set_timeout	= dc_wdt_set_timeout,
+	.get_timeleft	= dc_wdt_get_timeleft,
+	.restart        = dc_wdt_restart,
+};
+
+static const struct watchdog_info dc_wdt_info = {
+	.options	= WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE
+			| WDIOF_KEEPALIVEPING,
+	.identity	= "Conexant Digicolor Watchdog",
+};
+
+static struct watchdog_device dc_wdt_wdd = {
+	.info		= &dc_wdt_info,
+	.ops		= &dc_wdt_ops,
+	.min_timeout	= 1,
+};
+
+static int dc_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dc_wdt *wdt;
+
+	wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	wdt->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(wdt->base))
+		return PTR_ERR(wdt->base);
+
+	wdt->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(wdt->clk))
+		return PTR_ERR(wdt->clk);
+	dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk);
+	dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout;
+	dc_wdt_wdd.parent = dev;
+
+	spin_lock_init(&wdt->lock);
+
+	watchdog_set_drvdata(&dc_wdt_wdd, wdt);
+	watchdog_set_restart_priority(&dc_wdt_wdd, 128);
+	watchdog_init_timeout(&dc_wdt_wdd, timeout, dev);
+	watchdog_stop_on_reboot(&dc_wdt_wdd);
+	return devm_watchdog_register_device(dev, &dc_wdt_wdd);
+}
+
+static const struct of_device_id dc_wdt_of_match[] = {
+	{ .compatible = "cnxt,cx92755-wdt", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dc_wdt_of_match);
+
+static struct platform_driver dc_wdt_driver = {
+	.probe		= dc_wdt_probe,
+	.driver = {
+		.name =		"digicolor-wdt",
+		.of_match_table = dc_wdt_of_match,
+	},
+};
+module_platform_driver(dc_wdt_driver);
+
+MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
+MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer");
+MODULE_LICENSE("GPL");