linux-kernel - RE: [PATCH V8] iio: light: isl29018: add vcc regulator operation support

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Date:   Tue, 8 Jan 2019 09:16:57 +0000
From:   Anson Huang <anson.huang@....com>
To:     Jonathan Cameron <jic23@...nel.org>
CC:     "knaack.h@....de" <knaack.h@....de>,
        "lars@...afoo.de" <lars@...afoo.de>,
        "pmeerw@...erw.net" <pmeerw@...erw.net>,
        "linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        dl-linux-imx <linux-imx@....com>
Subject: RE: [PATCH V8] iio: light: isl29018: add vcc regulator operation
 support

Hi, Jonathan

Best Regards!
Anson Huang

> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@...nel.org]
> Sent: 2019年1月6日 1:43
> To: Anson Huang <anson.huang@....com>
> Cc: knaack.h@....de; lars@...afoo.de; pmeerw@...erw.net;
> linux-iio@...r.kernel.org; linux-kernel@...r.kernel.org; dl-linux-imx
> <linux-imx@....com>
> Subject: Re: [PATCH V8] iio: light: isl29018: add vcc regulator operation
> support
> 
> On Sun, 23 Dec 2018 06:46:32 +0000
> Anson Huang <anson.huang@....com> wrote:
> 
> > The light sensor's power supply could be controllable by regulator on
> > some platforms, such as i.MX6Q-SABRESD board, the light sensor
> > isl29023's power supply is controlled by a GPIO fixed regulator, need
> > to make sure the regulator is enabled before any operation of sensor,
> > this patch adds vcc regulator operation support.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@....com>
> 
> One comment inline on handling the error from devm_add_action.
> 
> Jonathan
> 
> > ---
> > ChangeLog Since V7:
> >     - move devm_add_action to before devm_regmap_init_i2c call to save
> code of disabling regulator;
> >     - simply the error check logic in isl29018_suspend.
> > ---
> >  drivers/iio/light/isl29018.c | 47
> > +++++++++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 46 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/light/isl29018.c
> > b/drivers/iio/light/isl29018.c index b45400f..ec6ce89 100644
> > --- a/drivers/iio/light/isl29018.c
> > +++ b/drivers/iio/light/isl29018.c
> > @@ -23,6 +23,7 @@
> >  #include <linux/mutex.h>
> >  #include <linux/delay.h>
> >  #include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> >  #include <linux/slab.h>
> >  #include <linux/iio/iio.h>
> >  #include <linux/iio/sysfs.h>
> > @@ -95,6 +96,7 @@ struct isl29018_chip {
> >  	struct isl29018_scale	scale;
> >  	int			prox_scheme;
> >  	bool			suspended;
> > +	struct regulator	*vcc_reg;
> >  };
> >
> >  static int isl29018_set_integration_time(struct isl29018_chip *chip,
> > @@ -708,6 +710,16 @@ static const char
> *isl29018_match_acpi_device(struct device *dev, int *data)
> >  	return dev_name(dev);
> >  }
> >
> > +static void isl29018_disable_regulator_action(void *_data) {
> > +	struct isl29018_chip *chip = _data;
> > +	int err;
> > +
> > +	err = regulator_disable(chip->vcc_reg);
> > +	if (err)
> > +		pr_err("failed to disable isl29018's VCC regulator!\n"); }
> > +
> >  static int isl29018_probe(struct i2c_client *client,
> >  			  const struct i2c_device_id *id)
> >  {
> > @@ -742,6 +754,28 @@ static int isl29018_probe(struct i2c_client *client,
> >  	chip->scale = isl29018_scales[chip->int_time][0];
> >  	chip->suspended = false;
> >
> > +	chip->vcc_reg = devm_regulator_get(&client->dev, "vcc");
> > +	if (IS_ERR(chip->vcc_reg)) {
> > +		err = PTR_ERR(chip->vcc_reg);
> > +		if (err != -EPROBE_DEFER)
> > +			dev_err(&client->dev, "failed to get VCC regulator!\n");
> > +		return err;
> > +	}
> > +
> > +	err = regulator_enable(chip->vcc_reg);
> > +	if (err) {
> > +		dev_err(&client->dev, "failed to enable VCC regulator!\n");
> > +		return err;
> > +	}
> > +
> > +	err = devm_add_action(&client->dev, isl29018_disable_regulator_action,
> > +				 chip);
> 
> Use devm_add_action_or_reset, then you don't need to call the disable if an
> error occurs in the add_action part...
> 
> > +	if (err) {
> > +		isl29018_disable_regulator_action(chip);
> 
> (will get rid of the line above).

Done in V9 patch, please help review, thanks.

Anson.

> 
> > +		dev_err(&client->dev, "failed to setup regulator cleanup action!\n");
> > +		return err;
> > +	}
> > +
> >  	chip->regmap = devm_regmap_init_i2c(client,
> >  				isl29018_chip_info_tbl[dev_id].regmap_cfg);
> >  	if (IS_ERR(chip->regmap)) {
> > @@ -768,6 +802,7 @@ static int isl29018_probe(struct i2c_client
> > *client,  static int isl29018_suspend(struct device *dev)  {
> >  	struct isl29018_chip *chip = iio_priv(dev_get_drvdata(dev));
> > +	int ret;
> >
> >  	mutex_lock(&chip->lock);
> >
> > @@ -777,10 +812,13 @@ static int isl29018_suspend(struct device *dev)
> >  	 * So we do not have much to do here.
> >  	 */
> >  	chip->suspended = true;
> > +	ret = regulator_disable(chip->vcc_reg);
> > +	if (ret)
> > +		dev_err(dev, "failed to disable VCC regulator\n");
> >
> >  	mutex_unlock(&chip->lock);
> >
> > -	return 0;
> > +	return ret;
> >  }
> >
> >  static int isl29018_resume(struct device *dev) @@ -790,6 +828,13 @@
> > static int isl29018_resume(struct device *dev)
> >
> >  	mutex_lock(&chip->lock);
> >
> > +	err = regulator_enable(chip->vcc_reg);
> > +	if (err) {
> > +		dev_err(dev, "failed to enable VCC regulator\n");
> > +		mutex_unlock(&chip->lock);
> > +		return err;
> > +	}
> > +
> >  	err = isl29018_chip_init(chip);
> >  	if (!err)
> >  		chip->suspended = false;