[PATCH V7] iio: light: isl29018: add vcc regulator operation support

[PATCH V7] iio: light: isl29018: add vcc regulator operation support

[Anson Huang]

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@nxp.com>
---
ChangeLog since V6
    - using devm_regulator_get() instead of devm_regulator_get_optional() since the regulator is
      there anyway, if dtb does NOT specify one, regulator framework will assign dummy regulator for it;
    - Setup devm action for cleaning up regulator resource for error handling.
---
 drivers/iio/light/isl29018.c | 58 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/drivers/iio/light/isl29018.c b/drivers/iio/light/isl29018.c
index b45400f..63f7b9d 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 +710,17 @@ 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)
+		dev_err(regmap_get_device(chip->regmap),
+			"failed to disable VCC regulator!\n");
+}
+
 static int isl29018_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
@@ -742,6 +755,37 @@ 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;
+	}
+
+	chip->regmap = devm_regmap_init_i2c(client,
+				isl29018_chip_info_tbl[dev_id].regmap_cfg);
+	if (IS_ERR(chip->regmap)) {
+		err = PTR_ERR(chip->regmap);
+		dev_err(&client->dev, "regmap initialization fails: %d\n", err);
+		regulator_disable(chip->vcc_reg);
+		return err;
+	}
+
+	err = devm_add_action(&client->dev, isl29018_disable_regulator_action,
+				 chip);
+	if (err) {
+		isl29018_disable_regulator_action(chip);
+		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 +812,7 @@ 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);
 
@@ -777,6 +822,12 @@ 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 ret;
+	}
 
 	mutex_unlock(&chip->lock);
 
@@ -790,6 +841,13 @@ 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;
-- 
2.7.4

Re: [PATCH V7] iio: light: isl29018: add vcc regulator operation support

[Jonathan Cameron]

On Mon, 17 Dec 2018 03:25:17 +0000
Anson Huang <anson.huang@nxp.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@nxp.com>
Hi Anson

See below.

> ---
> ChangeLog since V6
>     - using devm_regulator_get() instead of devm_regulator_get_optional() since the regulator is
>       there anyway, if dtb does NOT specify one, regulator framework will assign dummy regulator for it;
>     - Setup devm action for cleaning up regulator resource for error handling.
> ---
>  drivers/iio/light/isl29018.c | 58 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/drivers/iio/light/isl29018.c b/drivers/iio/light/isl29018.c
> index b45400f..63f7b9d 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 +710,17 @@ 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)
> +		dev_err(regmap_get_device(chip->regmap),
> +			"failed to disable VCC regulator!\n");
> +}
> +
>  static int isl29018_probe(struct i2c_client *client,
>  			  const struct i2c_device_id *id)
>  {
> @@ -742,6 +755,37 @@ 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;
> +	}
> +
> +	chip->regmap = devm_regmap_init_i2c(client,
> +				isl29018_chip_info_tbl[dev_id].regmap_cfg);
> +	if (IS_ERR(chip->regmap)) {
> +		err = PTR_ERR(chip->regmap);
> +		dev_err(&client->dev, "regmap initialization fails: %d\n", err);
> +		regulator_disable(chip->vcc_reg);
> +		return err;
> +	}
> +
> +	err = devm_add_action(&client->dev, isl29018_disable_regulator_action,
> +				 chip);
> +	if (err) {

I'm a little confused, why not do this before devm_regmap_init_i2c.
That way you won't have to disable the regulator in that one error path.
Also, devm_add_action_or_reset will call isl29018_disable_regulator_action for
you on error.

> +		isl29018_disable_regulator_action(chip);
> +		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 +812,7 @@ 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);
>  
> @@ -777,6 +822,12 @@ 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 ret;

Given you are about to unlock anyway a common pattern is to not
check ret until after the unlock, thus simplifying the code.

> +	}
>  
>  	mutex_unlock(&chip->lock);
>  
> @@ -790,6 +841,13 @@ 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;

RE: [PATCH V7] iio: light: isl29018: add vcc regulator operation support

[Anson Huang]

Hi, Jonathan

Best Regards!
Anson Huang

> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@kernel.org]
> Sent: 2018年12月23日 1:15
> To: Anson Huang <anson.huang@nxp.com>
> Cc: knaack.h@gmx.de; lars@metafoo.de; pmeerw@pmeerw.net;
> linux-iio@vger.kernel.org; linux-kernel@vger.kernel.org; festevam@gmail.com;
> preid@electromag.com.au; dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH V7] iio: light: isl29018: add vcc regulator operation
> support
> 
> On Mon, 17 Dec 2018 03:25:17 +0000
> Anson Huang <anson.huang@nxp.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@nxp.com>
> Hi Anson
> 
> See below.
> 
> > ---
> > ChangeLog since V6
> >     - using devm_regulator_get() instead of devm_regulator_get_optional()
> since the regulator is
> >       there anyway, if dtb does NOT specify one, regulator framework will
> assign dummy regulator for it;
> >     - Setup devm action for cleaning up regulator resource for error
> handling.
> > ---
> >  drivers/iio/light/isl29018.c | 58
> > ++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 58 insertions(+)
> >
> > diff --git a/drivers/iio/light/isl29018.c
> > b/drivers/iio/light/isl29018.c index b45400f..63f7b9d 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 +710,17 @@ 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)
> > +		dev_err(regmap_get_device(chip->regmap),
> > +			"failed to disable VCC regulator!\n"); }
> > +
> >  static int isl29018_probe(struct i2c_client *client,
> >  			  const struct i2c_device_id *id)
> >  {
> > @@ -742,6 +755,37 @@ 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;
> > +	}
> > +
> > +	chip->regmap = devm_regmap_init_i2c(client,
> > +				isl29018_chip_info_tbl[dev_id].regmap_cfg);
> > +	if (IS_ERR(chip->regmap)) {
> > +		err = PTR_ERR(chip->regmap);
> > +		dev_err(&client->dev, "regmap initialization fails: %d\n", err);
> > +		regulator_disable(chip->vcc_reg);
> > +		return err;
> > +	}
> > +
> > +	err = devm_add_action(&client->dev, isl29018_disable_regulator_action,
> > +				 chip);
> > +	if (err) {
> 
> I'm a little confused, why not do this before devm_regmap_init_i2c.
> That way you won't have to disable the regulator in that one error path.
> Also, devm_add_action_or_reset will call isl29018_disable_regulator_action
> for you on error.

It is because I used dev_err() in isl29018_disable_regulator_action which need regmap
to get "dev" by regmap_get_device(chip->regmap), if it is accepted by just using
pr_err() instead of dev_err, then I can do the devm_add_action before devm_regmap_init_i2c.

I think using pr_err should be OK, I will use it in V8 patch.

> 
> > +		isl29018_disable_regulator_action(chip);
> > +		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 +812,7 @@ 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);
> >
> > @@ -777,6 +822,12 @@ 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 ret;
> 
> Given you are about to unlock anyway a common pattern is to not check ret
> until after the unlock, thus simplifying the code.

I will improve this in V8 patch, thanks.

Anson.

> 
> > +	}
> >
> >  	mutex_unlock(&chip->lock);
> >
> > @@ -790,6 +841,13 @@ 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;