Re: [PATCH v2 3/4] watchdog: introduce retu_wdt driver

From: Tony Lindgren
Date: Tue Nov 06 2012 - 13:13:50 EST


* Aaro Koskinen <aaro.koskinen@xxxxxx> [121031 11:10]:
> Introduce Retu watchdog driver.

Added Wim Van Sebroeck <wim@xxxxxxxxx> to cc so he knows to
pick up the patches after no more comments. You may need
to resend.

Regards,

Tony

> Cc: linux-watchdog@xxxxxxxxxxxxxxx
> Acked-by: Felipe Balbi <balbi@xxxxxx>
> Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
> ---
> drivers/watchdog/Kconfig | 12 +++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/retu_wdt.c | 178 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 191 insertions(+), 0 deletions(-)
> create mode 100644 drivers/watchdog/retu_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index ad1bb93..c3a836d 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -352,6 +352,18 @@ config IMX2_WDT
> To compile this driver as a module, choose M here: the
> module will be called imx2_wdt.
>
> +config RETU_WATCHDOG
> + tristate "Retu watchdog"
> + depends on MFD_RETU
> + select WATCHDOG_CORE
> + help
> + Retu watchdog driver for Nokia Internet Tablets (700, N800,
> + N810). At least on N800 the watchdog cannot be disabled, so
> + this driver is essential and you should enable it.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called retu_wdt.
> +
> # AVR32 Architecture
>
> config AT32AP700X_WDT
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 572b39b..d2f1c0c 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -52,6 +52,7 @@ obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
> obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
> obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
> obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
> +obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
>
> # AVR32 Architecture
> obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
> diff --git a/drivers/watchdog/retu_wdt.c b/drivers/watchdog/retu_wdt.c
> new file mode 100644
> index 0000000..aeb0f39
> --- /dev/null
> +++ b/drivers/watchdog/retu_wdt.c
> @@ -0,0 +1,178 @@
> +/*
> + * Retu watchdog driver
> + *
> + * Copyright (C) 2004, 2005 Nokia Corporation
> + *
> + * Based on code written by Amit Kucheria and Michael Buesch.
> + * Rewritten by Aaro Koskinen.
> + *
> + * This file is subject to the terms and conditions of the GNU General
> + * Public License. See the file "COPYING" in the main directory of this
> + * archive for more details.
> + *
> + * 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.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/errno.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mfd/retu.h>
> +#include <linux/watchdog.h>
> +#include <linux/platform_device.h>
> +
> +/* Watchdog timer values in seconds */
> +#define RETU_WDT_MAX_TIMER 63
> +
> +struct retu_wdt_dev {
> + struct retu_dev *rdev;
> + struct device *dev;
> + struct delayed_work ping_work;
> +};
> +
> +/*
> + * Since Retu watchdog cannot be disabled in hardware, we must kick it
> + * with a timer until userspace watchdog software takes over. If
> + * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.
> + */
> +static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)
> +{
> + retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
> + schedule_delayed_work(&wdev->ping_work,
> + round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));
> +}
> +
> +static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)
> +{
> + retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
> + cancel_delayed_work_sync(&wdev->ping_work);
> +}
> +
> +static void retu_wdt_ping_work(struct work_struct *work)
> +{
> + struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),
> + struct retu_wdt_dev, ping_work);
> + retu_wdt_ping_enable(wdev);
> +}
> +
> +static int retu_wdt_start(struct watchdog_device *wdog)
> +{
> + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> +
> + retu_wdt_ping_disable(wdev);
> +
> + return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
> +}
> +
> +static int retu_wdt_stop(struct watchdog_device *wdog)
> +{
> + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> +
> + retu_wdt_ping_enable(wdev);
> +
> + return 0;
> +}
> +
> +static int retu_wdt_ping(struct watchdog_device *wdog)
> +{
> + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> +
> + return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
> +}
> +
> +static int retu_wdt_set_timeout(struct watchdog_device *wdog,
> + unsigned int timeout)
> +{
> + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> +
> + wdog->timeout = timeout;
> + return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
> +}
> +
> +static const struct watchdog_info retu_wdt_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
> + .identity = "Retu watchdog",
> +};
> +
> +static const struct watchdog_ops retu_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = retu_wdt_start,
> + .stop = retu_wdt_stop,
> + .ping = retu_wdt_ping,
> + .set_timeout = retu_wdt_set_timeout,
> +};
> +
> +static int __devinit retu_wdt_probe(struct platform_device *pdev)
> +{
> + struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
> + bool nowayout = WATCHDOG_NOWAYOUT;
> + struct watchdog_device *retu_wdt;
> + struct retu_wdt_dev *wdev;
> + int ret;
> +
> + retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL);
> + if (!retu_wdt)
> + return -ENOMEM;
> +
> + wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
> + if (!wdev)
> + return -ENOMEM;
> +
> + retu_wdt->info = &retu_wdt_info;
> + retu_wdt->ops = &retu_wdt_ops;
> + retu_wdt->timeout = RETU_WDT_MAX_TIMER;
> + retu_wdt->min_timeout = 0;
> + retu_wdt->max_timeout = RETU_WDT_MAX_TIMER;
> +
> + watchdog_set_drvdata(retu_wdt, wdev);
> + watchdog_set_nowayout(retu_wdt, nowayout);
> +
> + wdev->rdev = rdev;
> + wdev->dev = &pdev->dev;
> +
> + INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work);
> +
> + ret = watchdog_register_device(retu_wdt);
> + if (ret < 0)
> + return ret;
> +
> + if (nowayout)
> + retu_wdt_ping(retu_wdt);
> + else
> + retu_wdt_ping_enable(wdev);
> +
> + platform_set_drvdata(pdev, retu_wdt);
> +
> + return 0;
> +}
> +
> +static int __devexit retu_wdt_remove(struct platform_device *pdev)
> +{
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> +
> + watchdog_unregister_device(wdog);
> + cancel_delayed_work_sync(&wdev->ping_work);
> +
> + return 0;
> +}
> +
> +static struct platform_driver retu_wdt_driver = {
> + .probe = retu_wdt_probe,
> + .remove = __devexit_p(retu_wdt_remove),
> + .driver = {
> + .name = "retu-wdt",
> + },
> +};
> +module_platform_driver(retu_wdt_driver);
> +
> +MODULE_ALIAS("platform:retu-wdt");
> +MODULE_DESCRIPTION("Retu watchdog");
> +MODULE_AUTHOR("Amit Kucheria");
> +MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@xxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 1.7.2.5
>
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