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path: root/drivers/watchdog/loongson1_wdt.c
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Diffstat (limited to 'drivers/watchdog/loongson1_wdt.c')
-rw-r--r--drivers/watchdog/loongson1_wdt.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/watchdog/loongson1_wdt.c b/drivers/watchdog/loongson1_wdt.c
new file mode 100644
index 0000000000..0587ff44d3
--- /dev/null
+++ b/drivers/watchdog/loongson1_wdt.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+/* Loongson 1 Watchdog Register Definitions */
+#define WDT_EN 0x0
+#define WDT_TIMER 0x4
+#define WDT_SET 0x8
+
+#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 int ls1x_wdt_restart(struct watchdog_device *wdt_dev,
+ unsigned long action, void *data)
+{
+ struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+ writel(0x1, drvdata->base + WDT_EN);
+ writel(0x1, drvdata->base + WDT_TIMER);
+ writel(0x1, drvdata->base + WDT_SET);
+
+ 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,
+ .restart = ls1x_wdt_restart,
+};
+
+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_enabled(dev, NULL);
+ if (IS_ERR(drvdata->clk))
+ return PTR_ERR(drvdata->clk);
+
+ 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;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ls1x_wdt_dt_ids[] = {
+ { .compatible = "loongson,ls1b-wdt", },
+ { .compatible = "loongson,ls1c-wdt", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ls1x_wdt_dt_ids);
+#endif
+
+static struct platform_driver ls1x_wdt_driver = {
+ .probe = ls1x_wdt_probe,
+ .driver = {
+ .name = "ls1x-wdt",
+ .of_match_table = of_match_ptr(ls1x_wdt_dt_ids),
+ },
+};
+
+module_platform_driver(ls1x_wdt_driver);
+
+MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
+MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
+MODULE_LICENSE("GPL");