Re: [PATCH v3] watchdog: add driver for Ricoh RN5T618 watchdog

[Lee Jones <lee.jones@linaro.org>]

I'm not sure why a) this patch was sent to me in the first place and
b) why anyone would think this should go in through MFD?

> You have my Acked-by or Signbed-off-by on this one.
> I believe this goes via the mfd tree.

Wim,

When you Ack something, you should add your full Acked-by string.

Patches should only be Signed-off(-by) when you are part of the
distribution path i.e. when you send patches to another Maintainer
and/or Linus.

> > This adds a driver for the watchdog timer available in Ricoh RN5T618
> > PMIC. The device supports a programmable expiration time of 1, 8, 32
> > or 128 seconds.
> > 
> > Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> > Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> > ---
> > 
> > Hi,
> > 
> > this is the third version of Ricoh RN5T618 watchdog driver. The other
> > patches of the original series adding MFD and regulator support have
> > already been merged.
> > 
> > Changes since v2 (http://lwn.net/Articles/610000/ ):
> >   - rename 'heartbeat' module parameter to 'timeout'
> >   - change parameter type to uint
> > 
> > Changes since v1:
> >   - initialized heartbeat parameter to 0 instead of -1
> >   - simplified code path in set_timeout function
> >   - fixed module unloading
> >   - made 'time' unsigned in struct rn5t618_wdt_map
> > 
> >  drivers/watchdog/Kconfig       |  11 +++
> >  drivers/watchdog/Makefile      |   1 +
> >  drivers/watchdog/rn5t618_wdt.c | 198 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 210 insertions(+)
> >  create mode 100644 drivers/watchdog/rn5t618_wdt.c
> > 
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> > index 3ee951b..6fd5a87 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -327,6 +327,17 @@ config ORION_WATCHDOG
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called orion_wdt.
> >  
> > +config RN5T618_WATCHDOG
> > +	tristate "Ricoh RN5T618 watchdog"
> > +	depends on MFD_RN5T618
> > +	select WATCHDOG_CORE
> > +	help
> > +	  If you say yes here you get support for watchdog on the Ricoh
> > +	  RN5T618 PMIC.
> > +
> > +	  This driver can also be built as a module.  If so, the module
> > +	  will be called rn5t618_wdt.
> > +
> >  config SUNXI_WATCHDOG
> >  	tristate "Allwinner SoCs watchdog support"
> >  	depends on ARCH_SUNXI
> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> > index 44f5d68..f105999 100644
> > --- a/drivers/watchdog/Makefile
> > +++ b/drivers/watchdog/Makefile
> > @@ -48,6 +48,7 @@ obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
> >  obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
> >  obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
> >  obj-$(CONFIG_SUNXI_WATCHDOG) += sunxi_wdt.o
> > +obj-$(CONFIG_RN5T618_WATCHDOG) += rn5t618_wdt.o
> >  obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
> >  obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
> >  obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
> > diff --git a/drivers/watchdog/rn5t618_wdt.c b/drivers/watchdog/rn5t618_wdt.c
> > new file mode 100644
> > index 0000000..d1c1227
> > --- /dev/null
> > +++ b/drivers/watchdog/rn5t618_wdt.c
> > @@ -0,0 +1,198 @@
> > +/*
> > + * Watchdog driver for Ricoh RN5T618 PMIC
> > + *
> > + * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
> > + *
> > + * 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.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include <linux/device.h>
> > +#include <linux/mfd/rn5t618.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/watchdog.h>
> > +
> > +#define DRIVER_NAME "rn5t618-wdt"
> > +
> > +static bool nowayout = WATCHDOG_NOWAYOUT;
> > +static unsigned int timeout;
> > +
> > +module_param(timeout, uint, 0);
> > +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds");
> > +
> > +module_param(nowayout, bool, 0);
> > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> > +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > +
> > +struct rn5t618_wdt {
> > +	struct watchdog_device wdt_dev;
> > +	struct rn5t618 *rn5t618;
> > +};
> > +
> > +/*
> > + * This array encodes the values of WDOGTIM field for the supported
> > + * watchdog expiration times. If the watchdog is not accessed before
> > + * the timer expiration, the PMU generates an interrupt and if the CPU
> > + * doesn't clear it within one second the system is restarted.
> > + */
> > +static const struct {
> > +	u8 reg_val;
> > +	unsigned int time;
> > +} rn5t618_wdt_map[] = {
> > +	{ 0, 1 },
> > +	{ 1, 8 },
> > +	{ 2, 32 },
> > +	{ 3, 128 },
> > +};
> > +
> > +static int rn5t618_wdt_set_timeout(struct watchdog_device *wdt_dev,
> > +				   unsigned int t)
> > +{
> > +	struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> > +	int ret, i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(rn5t618_wdt_map); i++) {
> > +		if (rn5t618_wdt_map[i].time + 1 >= t)
> > +			break;
> > +	}
> > +
> > +	if (i == ARRAY_SIZE(rn5t618_wdt_map))
> > +		return -EINVAL;
> > +
> > +	ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG,
> > +				 RN5T618_WATCHDOG_WDOGTIM_M,
> > +				 rn5t618_wdt_map[i].reg_val);
> > +	if (!ret)
> > +		wdt_dev->timeout = rn5t618_wdt_map[i].time;
> > +
> > +	return ret;
> > +}
> > +
> > +static int rn5t618_wdt_start(struct watchdog_device *wdt_dev)
> > +{
> > +	struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> > +	int ret;
> > +
> > +	ret = rn5t618_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* enable repower-on */
> > +	ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_REPCNT,
> > +				 RN5T618_REPCNT_REPWRON,
> > +				 RN5T618_REPCNT_REPWRON);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* enable watchdog */
> > +	ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG,
> > +				 RN5T618_WATCHDOG_WDOGEN,
> > +				 RN5T618_WATCHDOG_WDOGEN);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* enable watchdog interrupt */
> > +	return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIREN,
> > +				  RN5T618_PWRIRQ_IR_WDOG,
> > +				  RN5T618_PWRIRQ_IR_WDOG);
> > +}
> > +
> > +static int rn5t618_wdt_stop(struct watchdog_device *wdt_dev)
> > +{
> > +	struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> > +
> > +	return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG,
> > +				  RN5T618_WATCHDOG_WDOGEN, 0);
> > +}
> > +
> > +static int rn5t618_wdt_ping(struct watchdog_device *wdt_dev)
> > +{
> > +	struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev);
> > +	unsigned int val;
> > +	int ret;
> > +
> > +	/* The counter is restarted after a R/W access to watchdog register */
> > +	ret = regmap_read(wdt->rn5t618->regmap, RN5T618_WATCHDOG, &val);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = regmap_write(wdt->rn5t618->regmap, RN5T618_WATCHDOG, val);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* Clear pending watchdog interrupt */
> > +	return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIRQ,
> > +				  RN5T618_PWRIRQ_IR_WDOG, 0);
> > +}
> > +
> > +static struct watchdog_info rn5t618_wdt_info = {
> > +	.options	= WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
> > +			  WDIOF_KEEPALIVEPING,
> > +	.identity	= DRIVER_NAME,
> > +};
> > +
> > +static struct watchdog_ops rn5t618_wdt_ops = {
> > +	.owner          = THIS_MODULE,
> > +	.start          = rn5t618_wdt_start,
> > +	.stop           = rn5t618_wdt_stop,
> > +	.ping           = rn5t618_wdt_ping,
> > +	.set_timeout    = rn5t618_wdt_set_timeout,
> > +};
> > +
> > +static int rn5t618_wdt_probe(struct platform_device *pdev)
> > +{
> > +	struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
> > +	struct rn5t618_wdt *wdt;
> > +	int min_timeout, max_timeout;
> > +
> > +	wdt = devm_kzalloc(&pdev->dev, sizeof(struct rn5t618_wdt), GFP_KERNEL);
> > +	if (!wdt)
> > +		return -ENOMEM;
> > +
> > +	min_timeout = rn5t618_wdt_map[0].time;
> > +	max_timeout = rn5t618_wdt_map[ARRAY_SIZE(rn5t618_wdt_map) - 1].time;
> > +
> > +	wdt->rn5t618 = rn5t618;
> > +	wdt->wdt_dev.info = &rn5t618_wdt_info;
> > +	wdt->wdt_dev.ops = &rn5t618_wdt_ops;
> > +	wdt->wdt_dev.min_timeout = min_timeout;
> > +	wdt->wdt_dev.max_timeout = max_timeout;
> > +	wdt->wdt_dev.timeout = max_timeout;
> > +	wdt->wdt_dev.parent = &pdev->dev;
> > +
> > +	watchdog_set_drvdata(&wdt->wdt_dev, wdt);
> > +	watchdog_init_timeout(&wdt->wdt_dev, timeout, &pdev->dev);
> > +	watchdog_set_nowayout(&wdt->wdt_dev, nowayout);
> > +
> > +	platform_set_drvdata(pdev, wdt);
> > +
> > +	return watchdog_register_device(&wdt->wdt_dev);
> > +}
> > +
> > +static int rn5t618_wdt_remove(struct platform_device *pdev)
> > +{
> > +	struct rn5t618_wdt *wdt = platform_get_drvdata(pdev);
> > +
> > +	watchdog_unregister_device(&wdt->wdt_dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver rn5t618_wdt_driver = {
> > +	.probe = rn5t618_wdt_probe,
> > +	.remove = rn5t618_wdt_remove,
> > +	.driver = {
> > +		.name	= DRIVER_NAME,
> > +	},
> > +};
> > +
> > +module_platform_driver(rn5t618_wdt_driver);
> > +
> > +MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
> > +MODULE_DESCRIPTION("RN5T618 watchdog driver");
> > +MODULE_LICENSE("GPL v2");

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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