@@ -578,6 +578,14 @@ config LPC18XX_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called lpc18xx_wdt.
+config SH_MOBILE_WDT
+ tristate "SH Mobile Watchdog"
+ depends on ARCH_SHMOBILE || COMPILE_TEST
+ select WATCHDOG_CORE
+ help
+ This driver adds watchdog support for the integrated watchdog in the
+ Renesas SH Mobile SoCs.
+
# AVR32 Architecture
config AT32AP700X_WDT
@@ -68,6 +68,7 @@ obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o
obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o
+obj-$(CONFIG_SH_MOBILE_WDT) += sh_mobile_wdt.o
# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
new file mode 100644
@@ -0,0 +1,187 @@
+/*
+ * Watchdog driver for SH mobile based SoC
+ *
+ * Copyright (C) 2015 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
+ * Copyright (C) 2015 Renesas Electronics Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define RWTCNT 0
+#define RWTCSRA 4
+#define RWTCSRA_WOVF BIT(4)
+#define RWTCSRA_WRFLG BIT(5)
+#define RWTCSRA_TME BIT(7)
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, S_IRUGO);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct sh_wdt_priv {
+ void __iomem *base;
+ struct watchdog_device wdev;
+ struct clk *clk;
+ struct notifier_block restart_handler;
+};
+
+static void sh_wdt_write(struct sh_wdt_priv *priv, u32 val, unsigned reg)
+{
+ if (reg == RWTCNT)
+ val |= 0x5a5a0000;
+ else
+ val |= 0xa5a5a500;
+
+ writel_relaxed(val, priv->base + reg);
+}
+
+static int sh_wdt_start(struct watchdog_device *wdev)
+{
+ struct sh_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+ clk_prepare_enable(priv->clk);
+
+ sh_wdt_write(priv, 0, RWTCSRA);
+ sh_wdt_write(priv, 0, RWTCNT);
+
+ while (readb_relaxed(priv->base + RWTCSRA) & RWTCSRA_WRFLG)
+ cpu_relax();
+
+ sh_wdt_write(priv, RWTCSRA_TME, RWTCSRA);
+
+ return 0;
+}
+
+static int sh_wdt_ping(struct watchdog_device *wdev)
+{
+ struct sh_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+ sh_wdt_write(priv, 0, RWTCNT);
+
+ return 0;
+}
+
+static int sh_wdt_stop(struct watchdog_device *wdev)
+{
+ struct sh_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+ sh_wdt_write(priv, 0, RWTCSRA);
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static const struct watchdog_info sh_wdt_ident = {
+ .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+ .identity = "SH Mobile Watchdog",
+};
+
+static const struct watchdog_ops sh_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = sh_wdt_start,
+ .ping = sh_wdt_ping,
+ .stop = sh_wdt_stop,
+};
+
+static int sh_mobile_wdt_restart_handler(struct notifier_block *nb,
+ unsigned long mode, void *cmd)
+{
+ struct sh_wdt_priv *priv = container_of(nb, struct sh_wdt_priv,
+ restart_handler);
+
+ sh_wdt_start(&priv->wdev);
+ sh_wdt_write(priv, 0xffff, RWTCNT);
+
+ return NOTIFY_DONE;
+}
+
+static int sh_wdt_probe(struct platform_device *pdev)
+{
+ struct sh_wdt_priv *priv;
+ struct resource *res;
+ unsigned long rate;
+ u8 status;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
+ clk_prepare_enable(priv->clk);
+ rate = clk_get_rate(priv->clk);
+ status = readb_relaxed(priv->base + RWTCSRA);
+ clk_disable_unprepare(priv->clk);
+
+ if (!rate)
+ return -ENOENT;
+
+ priv->wdev.info = &sh_wdt_ident,
+ priv->wdev.ops = &sh_wdt_ops,
+ priv->wdev.parent = &pdev->dev;
+ priv->wdev.bootstatus = (status & RWTCSRA_WOVF) ? WDIOF_CARDRESET : 0;
+ priv->wdev.timeout = 65536 / rate;
+
+ platform_set_drvdata(pdev, priv);
+ watchdog_set_drvdata(&priv->wdev, priv);
+ watchdog_set_nowayout(&priv->wdev, nowayout);
+
+ ret = watchdog_register_device(&priv->wdev);
+ if (ret < 0)
+ return ret;
+
+ priv->restart_handler.notifier_call = sh_mobile_wdt_restart_handler;
+ priv->restart_handler.priority = 192;
+ ret = register_restart_handler(&priv->restart_handler);
+ if (ret)
+ dev_warn(&pdev->dev, "Failed to register restart handler (err = %d)\n", ret);
+
+ return 0;
+}
+
+static int sh_wdt_remove(struct platform_device *pdev)
+{
+ struct sh_wdt_priv *priv = platform_get_drvdata(pdev);
+
+ unregister_restart_handler(&priv->restart_handler);
+ watchdog_unregister_device(&priv->wdev);
+ return 0;
+}
+
+static const struct of_device_id sh_mobile_wdt_ids[] = {
+ { .compatible = "renesas,rwdt-rcar", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sh_mobile_wdt_ids);
+
+static struct platform_driver sh_wdt_driver = {
+ .driver = {
+ .name = "sh_mobile_wdt",
+ .of_match_table = sh_mobile_wdt_ids,
+ },
+ .probe = sh_wdt_probe,
+ .remove = sh_wdt_remove,
+};
+module_platform_driver(sh_wdt_driver);
+
+MODULE_DESCRIPTION("SH Mobile Watchdog Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");