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

[Tony Lindgren <tony@atomide.com>]

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

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

Regards,

Tony
 
> Cc: linux-watchdog@vger.kernel.org
> Acked-by: Felipe Balbi <balbi@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> ---
>  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@iki.fi>");
> +MODULE_LICENSE("GPL");
> -- 
> 1.7.2.5
> 
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