Mediatek SoCs have a watchdog driver. This patch set adds driver and DTS
binding. The driver also implements a restart handler to reboot the SoC.
Matthias Brugger (2):
watchdog: Add driver for Mediatek mt6589 watchdog
ARM: mediatek: dts: Add bindings for watchdog
.../devicetree/bindings/watchdog/mtk-wdt.txt | 13 +
drivers/watchdog/Kconfig | 10 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/mtk_wdt.c | 264 +++++++++++++++++++++
4 files changed, 288 insertions(+)
create mode 100644 Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
create mode 100644 drivers/watchdog/mtk_wdt.c
--
1.9.1
This patch adds a driver for the Mediatek mt6589 SoC integrated
watchdog.
Signed-off-by: Matthias Brugger <[email protected]>
---
drivers/watchdog/Kconfig | 10 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/mtk_wdt.c | 264 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 275 insertions(+)
create mode 100644 drivers/watchdog/mtk_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index d0107d4..fcbca1b 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -505,6 +505,16 @@ config MESON_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called meson_wdt.
+config MEDIATEK_WATCHDOG
+ tristate "Mediatek SoCs watchdog support"
+ depends on ARCH_MEDIATEK
+ select WATCHDOG_CORE
+ help
+ Say Y here to include support for the watchdog timer
+ in Mediatek SoCs.
+ To compile this driver as a module, choose M here: the
+ module will be called mtk_wdt.
+
# AVR32 Architecture
config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index c569ec8..0d4821f 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -63,6 +63,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
+obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
new file mode 100644
index 0000000..4624821
--- /dev/null
+++ b/drivers/watchdog/mtk_wdt.c
@@ -0,0 +1,264 @@
+/*
+ * Mediatek Watchdog Driver
+ *
+ * Copyright (C) 2014 Matthias Brugger
+ *
+ * Matthias Brugger <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Based on mtk_wdt.c
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
+
+#define WDT_MAX_TIMEOUT 31
+#define WDT_MIN_TIMEOUT 1
+#define WDT_LENGTH_TIMEOUT(n) ((n) << 5)
+
+#define WDT_LENGTH 0x04
+#define WDT_LENGTH_KEY 0x8
+
+#define WDT_RST 0x08
+#define WDT_RST_RELOAD 0x1971
+
+#define WDT_MODE 0x00
+#define WDT_MODE_EN (1 << 0)
+#define WDT_MODE_EXT_POL_LOW (0 << 1)
+#define WDT_MODE_EXT_POL_HIGH (1 << 1)
+#define WDT_MODE_EXRST_EN (1 << 2)
+#define WDT_MODE_IRQ_EN (1 << 3)
+#define WDT_MODE_AUTO_START (1 << 4)
+#define WDT_MODE_DUAL_EN (1 << 6)
+#define WDT_MODE_KEY 0x22000000
+
+#define WDT_SWRST 0x14
+#define WDT_SWRST_KEY 0x1209
+
+#define DRV_NAME "mtk-wdt"
+#define DRV_VERSION "1.0"
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout = WDT_MAX_TIMEOUT;
+
+struct mtk_wdt_dev {
+ struct watchdog_device wdt_dev;
+ void __iomem *wdt_base;
+ struct notifier_block restart_handler;
+};
+
+static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
+ void *cmd)
+{
+ struct mtk_wdt_dev *mtk_wdt = container_of(this,
+ struct mtk_wdt_dev,
+ restart_handler);
+ void __iomem *wdt_base = mtk_wdt->wdt_base;
+ u32 reg;
+
+ /* Enable watchdog */
+ reg = readl(wdt_base + WDT_MODE);
+ reg |= WDT_MODE_EN;
+ writel(reg, wdt_base + WDT_MODE);
+
+ /* Reload counter */
+ writel(WDT_RST_RELOAD, wdt_base + WDT_RST);
+
+ /* Reset system */
+ writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
+
+ while (1) {
+ mdelay(5);
+ writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
+ }
+ return NOTIFY_DONE;
+
+}
+
+static int mtk_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = mtk_wdt->wdt_base;
+
+ iowrite32(WDT_RST_RELOAD, wdt_base + WDT_RST);
+
+ return 0;
+}
+
+static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = mtk_wdt->wdt_base;
+ u32 reg;
+
+ mtk_wdt->wdt_dev.timeout = timeout;
+
+ /* One bit is the value of 512 ticks
+ * The clock has 32 KHz
+ */
+ reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
+ iowrite32(reg, wdt_base + WDT_LENGTH);
+
+ mtk_wdt_ping(wdt_dev);
+
+ return 0;
+}
+
+static int mtk_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = mtk_wdt->wdt_base;
+ u32 reg;
+
+ reg = readl(wdt_base + WDT_MODE);
+ reg &= ~(WDT_MODE_EN);
+ iowrite32(reg, wdt_base + WDT_MODE);
+
+ return 0;
+}
+
+static int mtk_wdt_start(struct watchdog_device *wdt_dev)
+{
+ u32 reg;
+ struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = mtk_wdt->wdt_base;
+ u32 ret;
+
+ ret = mtk_wdt_set_timeout(&mtk_wdt->wdt_dev,
+ mtk_wdt->wdt_dev.timeout);
+ if (ret < 0)
+ return ret;
+
+ reg = ioread32(wdt_base + WDT_MODE);
+ reg |= (WDT_MODE_EN | WDT_MODE_KEY);
+ iowrite32(reg, wdt_base + WDT_MODE);
+
+ return 0;
+}
+
+static const struct watchdog_info mtk_wdt_info = {
+ .identity = DRV_NAME,
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops mtk_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = mtk_wdt_start,
+ .stop = mtk_wdt_stop,
+ .ping = mtk_wdt_ping,
+ .set_timeout = mtk_wdt_set_timeout,
+};
+
+static int mtk_wdt_probe(struct platform_device *pdev)
+{
+ struct mtk_wdt_dev *mtk_wdt;
+ struct resource *res;
+ int err;
+
+ mtk_wdt = devm_kzalloc(&pdev->dev, sizeof(*mtk_wdt), GFP_KERNEL);
+ if (!mtk_wdt)
+ return -EINVAL;
+
+ platform_set_drvdata(pdev, mtk_wdt);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mtk_wdt->wdt_base))
+ return PTR_ERR(mtk_wdt->wdt_base);
+
+ mtk_wdt->wdt_dev.info = &mtk_wdt_info;
+ mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
+ mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
+ mtk_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
+ mtk_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
+ mtk_wdt->wdt_dev.parent = &pdev->dev;
+
+ watchdog_init_timeout(&mtk_wdt->wdt_dev, timeout, &pdev->dev);
+ watchdog_set_nowayout(&mtk_wdt->wdt_dev, nowayout);
+
+ watchdog_set_drvdata(&mtk_wdt->wdt_dev, mtk_wdt);
+
+ mtk_wdt_stop(&mtk_wdt->wdt_dev);
+
+ err = watchdog_register_device(&mtk_wdt->wdt_dev);
+ if (unlikely(err))
+ return err;
+
+ mtk_wdt->restart_handler.notifier_call = mtk_reset_handler;
+ mtk_wdt->restart_handler.priority = 128;
+ err = register_restart_handler(&mtk_wdt->restart_handler);
+ if (err)
+ dev_err(&pdev->dev,
+ "cannot register restart handler (err=%d)\n", err);
+
+ dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
+ mtk_wdt->wdt_dev.timeout, nowayout);
+
+ return 0;
+}
+
+static int mtk_wdt_remove(struct platform_device *pdev)
+{
+ struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
+
+ unregister_restart_handler(&mtk_wdt->restart_handler);
+
+ watchdog_unregister_device(&mtk_wdt->wdt_dev);
+ watchdog_set_drvdata(&mtk_wdt->wdt_dev, NULL);
+
+ return 0;
+}
+
+static const struct of_device_id mtk_wdt_dt_ids[] = {
+ { .compatible = "mediatek,mt6589-wdt" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
+
+static struct platform_driver mtk_wdt_driver = {
+ .probe = mtk_wdt_probe,
+ .remove = mtk_wdt_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRV_NAME,
+ .of_match_table = mtk_wdt_dt_ids,
+ },
+};
+
+module_platform_driver(mtk_wdt_driver);
+
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Matthias Brugger <[email protected]>");
+MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);
--
1.9.1
Signed-off-by: Matthias Brugger <[email protected]>
---
Documentation/devicetree/bindings/watchdog/mtk-wdt.txt | 13 +++++++++++++
1 file changed, 13 insertions(+)
create mode 100644 Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
diff --git a/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt b/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
new file mode 100644
index 0000000..af9eb5b
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
@@ -0,0 +1,13 @@
+Mediatek SoCs Watchdog timer
+
+Required properties:
+
+- compatible : should be "mediatek,mt6589-wdt"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+wdt: watchdog@010000000 {
+ compatible = "mediatek,mt6589-wdt";
+ reg = <0x10000000 0x18>;
+};
--
1.9.1
On Tue, 2014-10-28 at 00:41 +0800, Matthias Brugger wrote:
> This patch adds a driver for the Mediatek mt6589 SoC integrated
> watchdog.
>
> Signed-off-by: Matthias Brugger <[email protected]>
> ---
> drivers/watchdog/Kconfig | 10 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/mtk_wdt.c | 264 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 275 insertions(+)
> create mode 100644 drivers/watchdog/mtk_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index d0107d4..fcbca1b 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -505,6 +505,16 @@ config MESON_WATCHDOG
> To compile this driver as a module, choose M here: the
> module will be called meson_wdt.
>
> +config MEDIATEK_WATCHDOG
> + tristate "Mediatek SoCs watchdog support"
> + depends on ARCH_MEDIATEK
> + select WATCHDOG_CORE
> + help
> + Say Y here to include support for the watchdog timer
> + in Mediatek SoCs.
> + To compile this driver as a module, choose M here: the
> + module will be called mtk_wdt.
> +
> # AVR32 Architecture
>
> config AT32AP700X_WDT
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index c569ec8..0d4821f 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -63,6 +63,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
> obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
> obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
> obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
> +obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
>
> # AVR32 Architecture
> obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> new file mode 100644
> index 0000000..4624821
> --- /dev/null
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -0,0 +1,264 @@
> +/*
> + * Mediatek Watchdog Driver
> + *
> + * Copyright (C) 2014 Matthias Brugger
> + *
> + * Matthias Brugger <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Based on mtk_wdt.c
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +#include <linux/watchdog.h>
> +#include <linux/notifier.h>
> +#include <linux/reboot.h>
> +#include <linux/delay.h>
> +
> +#define WDT_MAX_TIMEOUT 31
> +#define WDT_MIN_TIMEOUT 1
> +#define WDT_LENGTH_TIMEOUT(n) ((n) << 5)
> +
> +#define WDT_LENGTH 0x04
> +#define WDT_LENGTH_KEY 0x8
> +
> +#define WDT_RST 0x08
> +#define WDT_RST_RELOAD 0x1971
> +
> +#define WDT_MODE 0x00
> +#define WDT_MODE_EN (1 << 0)
> +#define WDT_MODE_EXT_POL_LOW (0 << 1)
> +#define WDT_MODE_EXT_POL_HIGH (1 << 1)
> +#define WDT_MODE_EXRST_EN (1 << 2)
> +#define WDT_MODE_IRQ_EN (1 << 3)
> +#define WDT_MODE_AUTO_START (1 << 4)
> +#define WDT_MODE_DUAL_EN (1 << 6)
> +#define WDT_MODE_KEY 0x22000000
> +
> +#define WDT_SWRST 0x14
> +#define WDT_SWRST_KEY 0x1209
> +
> +#define DRV_NAME "mtk-wdt"
> +#define DRV_VERSION "1.0"
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +static unsigned int timeout = WDT_MAX_TIMEOUT;
> +
> +struct mtk_wdt_dev {
> + struct watchdog_device wdt_dev;
> + void __iomem *wdt_base;
> + struct notifier_block restart_handler;
> +};
> +
> +static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
> + void *cmd)
> +{
> + struct mtk_wdt_dev *mtk_wdt = container_of(this,
> + struct mtk_wdt_dev,
> + restart_handler);
> + void __iomem *wdt_base = mtk_wdt->wdt_base;
> + u32 reg;
> +
> + /* Enable watchdog */
> + reg = readl(wdt_base + WDT_MODE);
> + reg |= WDT_MODE_EN;
> + writel(reg, wdt_base + WDT_MODE);
> +
> + /* Reload counter */
> + writel(WDT_RST_RELOAD, wdt_base + WDT_RST);
> +
> + /* Reset system */
> + writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
> +
> + while (1) {
> + mdelay(5);
> + writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
> + }
> + return NOTIFY_DONE;
> +
> +}
> +
> +static int mtk_wdt_ping(struct watchdog_device *wdt_dev)
> +{
> + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = mtk_wdt->wdt_base;
> +
> + iowrite32(WDT_RST_RELOAD, wdt_base + WDT_RST);
> +
> + return 0;
> +}
> +
> +static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
> + unsigned int timeout)
> +{
> + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = mtk_wdt->wdt_base;
> + u32 reg;
> +
> + mtk_wdt->wdt_dev.timeout = timeout;
> +
> + /* One bit is the value of 512 ticks
> + * The clock has 32 KHz
> + */
> + reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
> + iowrite32(reg, wdt_base + WDT_LENGTH);
> +
> + mtk_wdt_ping(wdt_dev);
> +
> + return 0;
> +}
> +
> +static int mtk_wdt_stop(struct watchdog_device *wdt_dev)
> +{
> + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = mtk_wdt->wdt_base;
> + u32 reg;
> +
> + reg = readl(wdt_base + WDT_MODE);
> + reg &= ~(WDT_MODE_EN);
> + iowrite32(reg, wdt_base + WDT_MODE);
> +
> + return 0;
> +}
> +
> +static int mtk_wdt_start(struct watchdog_device *wdt_dev)
> +{
> + u32 reg;
> + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> + void __iomem *wdt_base = mtk_wdt->wdt_base;
> + u32 ret;
> +
> + ret = mtk_wdt_set_timeout(&mtk_wdt->wdt_dev,
> + mtk_wdt->wdt_dev.timeout);
> + if (ret < 0)
> + return ret;
> +
> + reg = ioread32(wdt_base + WDT_MODE);
> + reg |= (WDT_MODE_EN | WDT_MODE_KEY);
According to datasheet, default value of register WDT_MODE bit6 is 1.
Which means when reach timeout, still need another timeout time to
restart the system. Should clear this bit to disable dual mode:
reg &= ~(WDT_MODE_DUAL_EN);
> + iowrite32(reg, wdt_base + WDT_MODE);
> +
> + return 0;
> +}
> +
> +static const struct watchdog_info mtk_wdt_info = {
> + .identity = DRV_NAME,
> + .options = WDIOF_SETTIMEOUT |
> + WDIOF_KEEPALIVEPING |
> + WDIOF_MAGICCLOSE,
> +};
> +
> +static const struct watchdog_ops mtk_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = mtk_wdt_start,
> + .stop = mtk_wdt_stop,
> + .ping = mtk_wdt_ping,
> + .set_timeout = mtk_wdt_set_timeout,
> +};
> +
> +static int mtk_wdt_probe(struct platform_device *pdev)
> +{
> + struct mtk_wdt_dev *mtk_wdt;
> + struct resource *res;
> + int err;
> +
> + mtk_wdt = devm_kzalloc(&pdev->dev, sizeof(*mtk_wdt), GFP_KERNEL);
> + if (!mtk_wdt)
> + return -EINVAL;
> +
> + platform_set_drvdata(pdev, mtk_wdt);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(mtk_wdt->wdt_base))
> + return PTR_ERR(mtk_wdt->wdt_base);
> +
> + mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> + mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
> + mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
> + mtk_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
> + mtk_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
> + mtk_wdt->wdt_dev.parent = &pdev->dev;
> +
> + watchdog_init_timeout(&mtk_wdt->wdt_dev, timeout, &pdev->dev);
> + watchdog_set_nowayout(&mtk_wdt->wdt_dev, nowayout);
> +
> + watchdog_set_drvdata(&mtk_wdt->wdt_dev, mtk_wdt);
> +
> + mtk_wdt_stop(&mtk_wdt->wdt_dev);
> +
> + err = watchdog_register_device(&mtk_wdt->wdt_dev);
> + if (unlikely(err))
> + return err;
> +
> + mtk_wdt->restart_handler.notifier_call = mtk_reset_handler;
> + mtk_wdt->restart_handler.priority = 128;
> + err = register_restart_handler(&mtk_wdt->restart_handler);
> + if (err)
> + dev_err(&pdev->dev,
> + "cannot register restart handler (err=%d)\n", err);
> +
> + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
> + mtk_wdt->wdt_dev.timeout, nowayout);
> +
> + return 0;
> +}
> +
> +static int mtk_wdt_remove(struct platform_device *pdev)
> +{
> + struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> +
> + unregister_restart_handler(&mtk_wdt->restart_handler);
> +
> + watchdog_unregister_device(&mtk_wdt->wdt_dev);
> + watchdog_set_drvdata(&mtk_wdt->wdt_dev, NULL);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id mtk_wdt_dt_ids[] = {
> + { .compatible = "mediatek,mt6589-wdt" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
> +
> +static struct platform_driver mtk_wdt_driver = {
> + .probe = mtk_wdt_probe,
> + .remove = mtk_wdt_remove,
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = DRV_NAME,
> + .of_match_table = mtk_wdt_dt_ids,
> + },
> +};
> +
> +module_platform_driver(mtk_wdt_driver);
> +
> +module_param(timeout, uint, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
> +
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Matthias Brugger <[email protected]>");
> +MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver");
> +MODULE_VERSION(DRV_VERSION);
> --
> 1.9.1
>
On Tue, 2014-11-11 at 19:29 +0800, Eddie Huang wrote:
> On Tue, 2014-10-28 at 00:41 +0800, Matthias Brugger wrote:
> > This patch adds a driver for the Mediatek mt6589 SoC integrated
> > watchdog.
> >
> > Signed-off-by: Matthias Brugger <[email protected]>
> > ---
> > drivers/watchdog/Kconfig | 10 ++
> > drivers/watchdog/Makefile | 1 +
> > drivers/watchdog/mtk_wdt.c | 264 +++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 275 insertions(+)
> > create mode 100644 drivers/watchdog/mtk_wdt.c
> > +
> > +static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
> > + void *cmd)
> > +{
> > + struct mtk_wdt_dev *mtk_wdt = container_of(this,
> > + struct mtk_wdt_dev,
> > + restart_handler);
> > + void __iomem *wdt_base = mtk_wdt->wdt_base;
> > + u32 reg;
> > +
> > + /* Enable watchdog */
> > + reg = readl(wdt_base + WDT_MODE);
> > + reg |= WDT_MODE_EN;
> > + writel(reg, wdt_base + WDT_MODE);
> > +
> > + /* Reload counter */
> > + writel(WDT_RST_RELOAD, wdt_base + WDT_RST);
> > +
> > + /* Reset system */
> > + writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
> > +
> > + while (1) {
> > + mdelay(5);
> > + writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
> > + }
> > + return NOTIFY_DONE;
> > +
> > +}
> > +
you can use "WDT_SWRST_KEY" to trigger reset signal. It is unnecessary
to enable watchdog and reload counter.
> +
> > +static int mtk_wdt_start(struct watchdog_device *wdt_dev)
> > +{
> > + u32 reg;
> > + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> > + void __iomem *wdt_base = mtk_wdt->wdt_base;
> > + u32 ret;
> > +
> > + ret = mtk_wdt_set_timeout(&mtk_wdt->wdt_dev,
> > + mtk_wdt->wdt_dev.timeout);
> > + if (ret < 0)
> > + return ret;
> > +
> > + reg = ioread32(wdt_base + WDT_MODE);
> > + reg |= (WDT_MODE_EN | WDT_MODE_KEY);
>
> According to datasheet, default value of register WDT_MODE bit6 is 1.
> Which means when reach timeout, still need another timeout time to
> restart the system. Should clear this bit to disable dual mode:
> reg &= ~(WDT_MODE_DUAL_EN);
>
> > + iowrite32(reg, wdt_base + WDT_MODE);
> > +
> > + return 0;
> > +}
According to datasheet, default value of register WDT_MODE bit3 and bit
6 is 1, 1'bit3 means trigger irq instead of reset, bit6 means open
dual_mode or not.
If you just set bit0 to 1 to enable watchdog, it will be irq +
dual_mode, which means it will trigger irq first when reach timeout,
still need another timeout time to trigger reset signal.
If you set bit bit6 to 0, it will be irq only, and when timeout
reaches,only irq happens, never reset.
So if want to trigger reset only,should clear bit3 and bit6 to disable
irq or dual_mode.
reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
I test this patch with above comment ok on my mt8135 tablet platform.