diff mbox

[v2,1/2] watchdog: Add driver for Mediatek watchdog

Message ID 1418395859-32209-2-git-send-email-matthias.bgg@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Matthias Brugger Dec. 12, 2014, 2:50 p.m. UTC 
This patch adds a driver for the Mediatek SoC integrated
watchdog. This driver supports watchdog and software reset
for mt65xx and mt81xx SoCs.

Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
---
 drivers/watchdog/Kconfig   |  10 ++
 drivers/watchdog/Makefile  |   1 +
 drivers/watchdog/mtk_wdt.c | 257 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 268 insertions(+)
 create mode 100644 drivers/watchdog/mtk_wdt.c

Comments

Chen-Yu Tsai Dec. 13, 2014, 2:08 a.m. UTC | #1 
Hi,

On Fri, Dec 12, 2014 at 10:50 PM, Matthias Brugger
<matthias.bgg@gmail.com> wrote:
> This patch adds a driver for the Mediatek SoC integrated
> watchdog. This driver supports watchdog and software reset
> for mt65xx and mt81xx SoCs.
>
> Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
> ---
>  drivers/watchdog/Kconfig   |  10 ++
>  drivers/watchdog/Makefile  |   1 +
>  drivers/watchdog/mtk_wdt.c | 257 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 268 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..5f75442
> --- /dev/null
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -0,0 +1,257 @@
> +/*
> + * Mediatek Watchdog Driver
> + *
> + * Copyright (C) 2014 Matthias Brugger
> + *
> + * Matthias Brugger <matthias.bgg@gmail.com>
> + *
> + * 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

Did you base your code on itself from the future? :)

ChenYu

> + */
> +
> +#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;
> +
> +       /* 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_IRQ_EN | WDT_MODE_DUAL_EN);
> +       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 <matthias.bgg@gmail.com>");
> +MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver");
> +MODULE_VERSION(DRV_VERSION);
> --
> 1.9.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Guenter Roeck Dec. 13, 2014, 3:44 p.m. UTC | #2 
On 12/12/2014 06:50 AM, Matthias Brugger wrote:
> This patch adds a driver for the Mediatek SoC integrated
> watchdog. This driver supports watchdog and software reset
> for mt65xx and mt81xx SoCs.
>
> Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
> ---
>   drivers/watchdog/Kconfig   |  10 ++
>   drivers/watchdog/Makefile  |   1 +
>   drivers/watchdog/mtk_wdt.c | 257 +++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 268 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..5f75442
> --- /dev/null
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -0,0 +1,257 @@
> +/*
> + * Mediatek Watchdog Driver
> + *
> + * Copyright (C) 2014 Matthias Brugger
> + *
> + * Matthias Brugger <matthias.bgg@gmail.com>
> + *
> + * 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;
> +
> +	/* 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;
> +
Unnecessary empty line. See checkpatch --strict.

> +}
> +
> +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)

Continuation line alignment is off. See checkpatch --strict.

> +{
> +	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

Please use standard multi-line comment style.

> +	 * 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_IRQ_EN | WDT_MODE_DUAL_EN);
> +	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;

-ENOMEM

> +
> +	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,

dev_warn

> +			"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);

Unnecessary. mtk_wdt is about to be freed.

> +
> +	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 <matthias.bgg@gmail.com>");
> +MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver");
> +MODULE_VERSION(DRV_VERSION);
>
Eddie Huang (黃智傑) Dec. 15, 2014, 3:37 a.m. UTC | #3 
Hi,

On Fri, 2014-12-12 at 15:50 +0100, Matthias Brugger wrote:
> This patch adds a driver for the Mediatek SoC integrated
> watchdog. This driver supports watchdog and software reset
> for mt65xx and mt81xx SoCs.
> 
> Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

> +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;
> +
> +	/* 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;
> +
> +}

Build warning
../drivers/watchdog/mtk_wdt.c:78:6: warning: unused variable
'reg' [-Wunused-variable]
diff mbox

Patch

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..5f75442
--- /dev/null
+++ b/drivers/watchdog/mtk_wdt.c
@@ -0,0 +1,257 @@ 
+/*
+ * Mediatek Watchdog Driver
+ *
+ * Copyright (C) 2014 Matthias Brugger
+ *
+ * Matthias Brugger <matthias.bgg@gmail.com>
+ *
+ * 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;
+
+	/* 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_IRQ_EN | WDT_MODE_DUAL_EN);
+	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 <matthias.bgg@gmail.com>");
+MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);