1 files changed, 156 insertions, 0 deletions

diff --git a/drivers/watchdog/loongson1_wdt.c b/drivers/watchdog/loongson1_wdt.c
new file mode 100644
index 000000000..bb3d075c0
--- /dev/null
+++ b/drivers/watchdog/loongson1_wdt.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <loongson1.h>
+
+#define DEFAULT_HEARTBEAT	30
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0444);
+
+static unsigned int heartbeat;
+module_param(heartbeat, uint, 0444);
+
+struct ls1x_wdt_drvdata {
+	void __iomem *base;
+	struct clk *clk;
+	unsigned long clk_rate;
+	struct watchdog_device wdt;
+};
+
+static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
+{
+	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+	writel(0x1, drvdata->base + WDT_SET);
+
+	return 0;
+}
+
+static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
+				unsigned int timeout)
+{
+	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+	unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
+	unsigned int counts;
+
+	wdt_dev->timeout = timeout;
+
+	counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
+	writel(counts, drvdata->base + WDT_TIMER);
+
+	return 0;
+}
+
+static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
+{
+	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+	writel(0x1, drvdata->base + WDT_EN);
+
+	return 0;
+}
+
+static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+	writel(0x0, drvdata->base + WDT_EN);
+
+	return 0;
+}
+
+static const struct watchdog_info ls1x_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "Loongson1 Watchdog",
+};
+
+static const struct watchdog_ops ls1x_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = ls1x_wdt_start,
+	.stop = ls1x_wdt_stop,
+	.ping = ls1x_wdt_ping,
+	.set_timeout = ls1x_wdt_set_timeout,
+};
+
+static void ls1x_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int ls1x_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ls1x_wdt_drvdata *drvdata;
+	struct watchdog_device *ls1x_wdt;
+	unsigned long clk_rate;
+	int err;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(drvdata->base))
+		return PTR_ERR(drvdata->base);
+
+	drvdata->clk = devm_clk_get(dev, pdev->name);
+	if (IS_ERR(drvdata->clk))
+		return PTR_ERR(drvdata->clk);
+
+	err = clk_prepare_enable(drvdata->clk);
+	if (err) {
+		dev_err(dev, "clk enable failed\n");
+		return err;
+	}
+	err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
+				       drvdata->clk);
+	if (err)
+		return err;
+
+	clk_rate = clk_get_rate(drvdata->clk);
+	if (!clk_rate)
+		return -EINVAL;
+	drvdata->clk_rate = clk_rate;
+
+	ls1x_wdt = &drvdata->wdt;
+	ls1x_wdt->info = &ls1x_wdt_info;
+	ls1x_wdt->ops = &ls1x_wdt_ops;
+	ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
+	ls1x_wdt->min_timeout = 1;
+	ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
+	ls1x_wdt->parent = dev;
+
+	watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
+	watchdog_set_nowayout(ls1x_wdt, nowayout);
+	watchdog_set_drvdata(ls1x_wdt, drvdata);
+
+	err = devm_watchdog_register_device(dev, &drvdata->wdt);
+	if (err)
+		return err;
+
+	platform_set_drvdata(pdev, drvdata);
+
+	dev_info(dev, "Loongson1 Watchdog driver registered\n");
+
+	return 0;
+}
+
+static struct platform_driver ls1x_wdt_driver = {
+	.probe = ls1x_wdt_probe,
+	.driver = {
+		.name = "ls1x-wdt",
+	},
+};
+
+module_platform_driver(ls1x_wdt_driver);
+
+MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
+MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
+MODULE_LICENSE("GPL");