[v4] watchdog: Add DA906x PMIC watchdog driver.

Markus Pargmann mpa at pengutronix.de
Wed Aug 20 23:15:25 PDT 2014


Hi,

On Wed, Aug 20, 2014 at 07:43:22AM -0700, Guenter Roeck wrote:
> On Sat, Aug 16, 2014 at 02:35:45PM +0200, Markus Pargmann wrote:
> > From: Krystian Garbaciak <krystian.garbaciak at diasemi.com>
> > 
> > This driver supports the watchdog device inside the DA906x PMIC.
> > 
> > Signed-off-by: Krystian Garbaciak <krystian.garbaciak at diasemi.com>
> > Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
> > Signed-off-by: Markus Pargmann <mpa at pengutronix.de>
> > 
> > ---
> > Notes:
> >     Changes in v4:
> >      - Fixed indentation
> >      - Fixed lock without unlock
> >      - Check for parent device and device driver data in probe(). If not present,
> >        this is an invalid prober initialization, return -EINVAL.
> >     
> >     Changes in v3:
> >      - Cleanup error handling for timeout selection and setting
> >      - Fix race condition due to late wdt drvdata setup
> >      - Remove static struct watchdog_device. It is not initialized in the probe
> >        function
> >      - Use WATCHDOG_NOWAYOUT_INIT_STATUS for the status
> >      - Remove 0 shift using DA9063_TWDSCALE_SHIFT
> > 
> >  drivers/watchdog/Kconfig      |   7 ++
> >  drivers/watchdog/Makefile     |   1 +
> >  drivers/watchdog/da9063_wdt.c | 231 ++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 239 insertions(+)
> >  create mode 100644 drivers/watchdog/da9063_wdt.c
> > 
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> > index c845527b503a..8d5c9b33552a 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -87,6 +87,13 @@ config DA9055_WATCHDOG
> >  	  This driver can also be built as a module.  If so, the module
> >  	  will be called da9055_wdt.
> >  
> > +config DA9063_WATCHDOG
> > +	tristate "Dialog DA9063 Watchdog"
> > +	depends on MFD_DA9063
> > +	select WATCHDOG_CORE
> > +	help
> > +	  Support for the watchdog in the DA9063 PMIC.
> > +
> Please add a note such as above, listing the module name.

Added such a note.

> 
> >  config GPIO_WATCHDOG
> >  	tristate "Watchdog device controlled through GPIO-line"
> >  	depends on OF_GPIO
> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> > index 7b8a91ed20e7..ce4a7632d863 100644
> > --- a/drivers/watchdog/Makefile
> > +++ b/drivers/watchdog/Makefile
> > @@ -172,6 +172,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o
> >  # Architecture Independent
> >  obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
> >  obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
> > +obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o
> >  obj-$(CONFIG_GPIO_WATCHDOG)	+= gpio_wdt.o
> >  obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
> >  obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
> > diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
> > new file mode 100644
> > index 000000000000..a2d46bc55805
> > --- /dev/null
> > +++ b/drivers/watchdog/da9063_wdt.c
> > @@ -0,0 +1,231 @@
> > +/*
> > + * Watchdog driver for DA9063 PMICs.
> > + *
> > + * Copyright(c) 2012 Dialog Semiconductor Ltd.
> > + *
> > + * Author: Mariusz Wojtasik <mariusz.wojtasik at diasemi.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.
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/watchdog.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/uaccess.h>
> > +#include <linux/slab.h>
> > +#include <linux/delay.h>
> > +#include <linux/mfd/da9063/registers.h>
> > +#include <linux/mfd/da9063/core.h>
> > +#include <linux/regmap.h>
> > +
> > +/*
> > + * Watchdog selector to timeout in seconds.
> > + *   0: WDT disabled;
> > + *   others: timeout = 2048 ms * 2^(TWDSCALE-1).
> > + */
> > +static const int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
> > +#define DA9063_TWDSCALE_DISABLE		0
> > +#define DA9063_TWDSCALE_MIN		1
> > +#define DA9063_TWDSCALE_MAX		(ARRAY_SIZE(wdt_timeout) - 1)
> > +#define DA9063_WDT_MIN_TIMEOUT		wdt_timeout[DA9063_TWDSCALE_MIN]
> > +#define DA9063_WDT_MAX_TIMEOUT		wdt_timeout[DA9063_TWDSCALE_MAX]
> > +#define DA9063_WDG_TIMEOUT		wdt_timeout[3]
> > +
> > +struct da9063_watchdog {
> > +	struct da9063 *da9063;
> > +	struct watchdog_device wdtdev;
> > +	struct mutex lock;
> > +};
> > +
> > +static int da9063_wdt_timeout_to_sel(int secs)
> > +{
> > +	int i;
> > +
> > +	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
> 
> When building with W=1, gcc complains about this line. Would be great if you can
> have a look and fix it.

I just compiled with W=1, it doesn't complain here about this line.
Could you give me the warning?

> 
> > +		if (wdt_timeout[i] >= secs)
> > +			return i;
> > +	}
> > +
> > +	return -EINVAL;
> > +}
> > +
> > +static int da9063_wdt_disable(struct da9063 *da9063)
> > +{
> > +	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
> > +			DA9063_TWDSCALE_MASK,
> > +			DA9063_TWDSCALE_DISABLE);
> > +}
> > +
> > +static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
> > +{
> > +	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
> > +			DA9063_TWDSCALE_MASK, regval);
> > +}
> > +
> > +static int _da9063_wdt_kick(struct da9063 *da9063)
> > +{
> > +	return regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
> > +			DA9063_WATCHDOG);
> > +}
> > +
> > +static int da9063_wdt_start(struct watchdog_device *wdd)
> > +{
> > +	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
> > +	unsigned int selector;
> > +	int ret;
> > +
> > +	selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout);
> > +	if (selector < 0) {
> 
> selector has to be an int for this to work. Building the driver with W=1 reports
> it, btw.

Yes, thanks, I changed both selector variables to int.

> 
> > +		dev_err(wdt->da9063->dev, "Timeout out of range (timeout=%d)\n",
> > +				wdt->wdtdev.timeout);
> > +		return selector;
> > +	}
> > +
> > +	mutex_lock(&wdt->lock);
> > +	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
> > +	if (ret) {
> > +		dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
> > +				ret);
> > +	}
> > +	mutex_unlock(&wdt->lock);
> > +
> > +	return ret;
> > +}
> > +
> > +static int da9063_wdt_stop(struct watchdog_device *wdd)
> > +{
> > +	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
> > +	int ret;
> > +
> > +	mutex_lock(&wdt->lock);
> > +	ret = da9063_wdt_disable(wdt->da9063);
> > +	if (ret)
> > +		dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
> > +				ret);
> 
> You have a number of places where the continuation line _on purpose_
> does not align to te opening '('. I would understand it if your indentation
> rules were in any way consistent, but I don't see that either.
> Ok, I can see that you dislike the rule that continuation lines should be
> aligned to '(', but to misalign even when the '(' matches a tab position doesn't
> really make any sense.

My indentation rules are consistent, otherwise I made a mistake. I
always indent two tabs after an opening bracket when breaking long
lines. Also I can't find any specific rules about how to break long
lines in the coding style document.

> 
> > +	mutex_unlock(&wdt->lock);
> > +
> > +	return ret;
> > +}
> > +
> > +static int da9063_wdt_ping(struct watchdog_device *wdd)
> > +{
> > +	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
> > +	int ret;
> > +
> > +	mutex_lock(&wdt->lock);
> > +	ret = _da9063_wdt_kick(wdt->da9063);
> > +	if (ret)
> > +		dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n",
> > +				ret);
> > +	mutex_unlock(&wdt->lock);
> > +
> > +	return ret;
> > +}
> > +
> > +static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
> > +		unsigned int timeout)
> > +{
> > +	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
> > +	unsigned int selector;
> > +	int ret;
> > +
> > +	selector = da9063_wdt_timeout_to_sel(timeout);
> > +	if (selector < 0) {
> 
> selector must be an int for this to work.
> 
> > +		dev_err(wdt->da9063->dev, "Unsupported watchdog timeout, should be between 2 and 131\n");
> 
> Please use a continuation line here.

Ok.

Thank you,

Markus

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