2021-11-26 09:03:30

by Martin Kepplinger

[permalink] [raw]
Subject: [PATCH v2] media: i2c: dw9714: add optional regulator support

From: Angus Ainslie <[email protected]>

Allow the dw9714 to control a regulator and adjust suspend() and resume()
to support both runtime and system pm.

Signed-off-by: Angus Ainslie <[email protected]>
Signed-off-by: Martin Kepplinger <[email protected]>
---

revision history
----------------

v2: (thank you Mark)
* simplify the regulator_get_optional() error path
* fix regulator usage during probe()

v1:
https://lore.kernel.org/linux-media/[email protected]/



drivers/media/i2c/dw9714.c | 39 ++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/drivers/media/i2c/dw9714.c b/drivers/media/i2c/dw9714.c
index 3863dfeb8293..e8cc19b89861 100644
--- a/drivers/media/i2c/dw9714.c
+++ b/drivers/media/i2c/dw9714.c
@@ -5,6 +5,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
@@ -36,6 +37,7 @@ struct dw9714_device {
struct v4l2_ctrl_handler ctrls_vcm;
struct v4l2_subdev sd;
u16 current_val;
+ struct regulator *vcc;
};

static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl *ctrl)
@@ -145,6 +147,21 @@ static int dw9714_probe(struct i2c_client *client)
if (dw9714_dev == NULL)
return -ENOMEM;

+ dw9714_dev->vcc = devm_regulator_get_optional(&client->dev, "vcc");
+ if (IS_ERR(dw9714_dev->vcc)) {
+ dev_dbg(&client->dev, "No vcc regulator found: %ld\n",
+ PTR_ERR(dw9714_dev->vcc));
+ dw9714_dev->vcc = NULL;
+ }
+
+ if (dw9714_dev->vcc) {
+ rval = regulator_enable(dw9714_dev->vcc);
+ if (rval < 0) {
+ dev_err(&client->dev, "failed to enable vcc: %d\n", rval);
+ return rval;
+ }
+ }
+
v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
V4L2_SUBDEV_FL_HAS_EVENTS;
@@ -200,6 +217,9 @@ static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
int ret, val;

+ if (pm_runtime_suspended(&client->dev))
+ return 0;
+
for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - 1);
val >= 0; val -= DW9714_CTRL_STEPS) {
ret = dw9714_i2c_write(client,
@@ -208,6 +228,13 @@ static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
}
+
+ if (dw9714_dev->vcc) {
+ ret = regulator_disable(dw9714_dev->vcc);
+ if (ret)
+ dev_err(dev, "Failed to disable vcc: %d\n", ret);
+ }
+
return 0;
}

@@ -224,6 +251,18 @@ static int __maybe_unused dw9714_vcm_resume(struct device *dev)
struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
int ret, val;

+ if (pm_runtime_suspended(&client->dev))
+ return 0;
+
+ if (dw9714_dev->vcc) {
+ ret = regulator_enable(dw9714_dev->vcc);
+ if (ret) {
+ dev_err(dev, "Failed to enable vcc: %d\n", ret);
+ return ret;
+ }
+ usleep_range(1000, 2000);
+ }
+
for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
val += DW9714_CTRL_STEPS) {
--
2.30.2



2021-11-26 10:48:14

by Sakari Ailus

[permalink] [raw]
Subject: Re: [PATCH v2] media: i2c: dw9714: add optional regulator support

Hi Martin,

On Fri, Nov 26, 2021 at 10:01:07AM +0100, Martin Kepplinger wrote:
> From: Angus Ainslie <[email protected]>
>
> Allow the dw9714 to control a regulator and adjust suspend() and resume()
> to support both runtime and system pm.
>
> Signed-off-by: Angus Ainslie <[email protected]>
> Signed-off-by: Martin Kepplinger <[email protected]>
> ---
>
> revision history
> ----------------
>
> v2: (thank you Mark)
> * simplify the regulator_get_optional() error path
> * fix regulator usage during probe()
>
> v1:
> https://lore.kernel.org/linux-media/[email protected]/
>
>
>
> drivers/media/i2c/dw9714.c | 39 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/drivers/media/i2c/dw9714.c b/drivers/media/i2c/dw9714.c
> index 3863dfeb8293..e8cc19b89861 100644
> --- a/drivers/media/i2c/dw9714.c
> +++ b/drivers/media/i2c/dw9714.c
> @@ -5,6 +5,7 @@
> #include <linux/i2c.h>
> #include <linux/module.h>
> #include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-event.h>
> @@ -36,6 +37,7 @@ struct dw9714_device {
> struct v4l2_ctrl_handler ctrls_vcm;
> struct v4l2_subdev sd;
> u16 current_val;
> + struct regulator *vcc;
> };
>
> static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl *ctrl)
> @@ -145,6 +147,21 @@ static int dw9714_probe(struct i2c_client *client)
> if (dw9714_dev == NULL)
> return -ENOMEM;
>
> + dw9714_dev->vcc = devm_regulator_get_optional(&client->dev, "vcc");

You you used regular devm_regulator_get(), you could remove the error
handling below. If there's no regulator, you'll simply get a dummy one.

> + if (IS_ERR(dw9714_dev->vcc)) {
> + dev_dbg(&client->dev, "No vcc regulator found: %ld\n",
> + PTR_ERR(dw9714_dev->vcc));
> + dw9714_dev->vcc = NULL;
> + }
> +
> + if (dw9714_dev->vcc) {

With (dummy) regulators, these checks become unnecessary.

> + rval = regulator_enable(dw9714_dev->vcc);
> + if (rval < 0) {
> + dev_err(&client->dev, "failed to enable vcc: %d\n", rval);
> + return rval;
> + }
> + }
> +
> v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
> dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> V4L2_SUBDEV_FL_HAS_EVENTS;
> @@ -200,6 +217,9 @@ static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
> struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
> int ret, val;
>
> + if (pm_runtime_suspended(&client->dev))
> + return 0;

This can't take place in a runtime PM suspend callback. You'll need to add
system suspend callback for this.

> +
> for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - 1);
> val >= 0; val -= DW9714_CTRL_STEPS) {
> ret = dw9714_i2c_write(client,
> @@ -208,6 +228,13 @@ static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
> dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
> usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
> }
> +
> + if (dw9714_dev->vcc) {
> + ret = regulator_disable(dw9714_dev->vcc);
> + if (ret)
> + dev_err(dev, "Failed to disable vcc: %d\n", ret);
> + }
> +
> return 0;
> }
>
> @@ -224,6 +251,18 @@ static int __maybe_unused dw9714_vcm_resume(struct device *dev)
> struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
> int ret, val;
>
> + if (pm_runtime_suspended(&client->dev))

Same for this one.

> + return 0;
> +
> + if (dw9714_dev->vcc) {
> + ret = regulator_enable(dw9714_dev->vcc);
> + if (ret) {
> + dev_err(dev, "Failed to enable vcc: %d\n", ret);
> + return ret;
> + }
> + usleep_range(1000, 2000);
> + }
> +
> for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
> val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
> val += DW9714_CTRL_STEPS) {

--
Kind regards,

Sakari Ailus

2021-11-26 11:08:41

by Martin Kepplinger

[permalink] [raw]
Subject: Re: [PATCH v2] media: i2c: dw9714: add optional regulator support

Am Freitag, dem 26.11.2021 um 12:44 +0200 schrieb Sakari Ailus:
> Hi Martin,
>
> On Fri, Nov 26, 2021 at 10:01:07AM +0100, Martin Kepplinger wrote:
> > From: Angus Ainslie <[email protected]>
> >
> > Allow the dw9714 to control a regulator and adjust suspend() and
> > resume()
> > to support both runtime and system pm.
> >
> > Signed-off-by: Angus Ainslie <[email protected]>
> > Signed-off-by: Martin Kepplinger <[email protected]>
> > ---
> >
> > revision history
> > ----------------
> >
> > v2: (thank you Mark)
> >  * simplify the regulator_get_optional() error path
> >  * fix regulator usage during probe()
> >
> > v1:
> > https://lore.kernel.org/linux-media/[email protected]/
> >
> >
> >
> >  drivers/media/i2c/dw9714.c | 39
> > ++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 39 insertions(+)
> >
> > diff --git a/drivers/media/i2c/dw9714.c
> > b/drivers/media/i2c/dw9714.c
> > index 3863dfeb8293..e8cc19b89861 100644
> > --- a/drivers/media/i2c/dw9714.c
> > +++ b/drivers/media/i2c/dw9714.c
> > @@ -5,6 +5,7 @@
> >  #include <linux/i2c.h>
> >  #include <linux/module.h>
> >  #include <linux/pm_runtime.h>
> > +#include <linux/regulator/consumer.h>
> >  #include <media/v4l2-ctrls.h>
> >  #include <media/v4l2-device.h>
> >  #include <media/v4l2-event.h>
> > @@ -36,6 +37,7 @@ struct dw9714_device {
> >         struct v4l2_ctrl_handler ctrls_vcm;
> >         struct v4l2_subdev sd;
> >         u16 current_val;
> > +       struct regulator *vcc;
> >  };
> >  
> >  static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl
> > *ctrl)
> > @@ -145,6 +147,21 @@ static int dw9714_probe(struct i2c_client
> > *client)
> >         if (dw9714_dev == NULL)
> >                 return -ENOMEM;
> >  
> > +       dw9714_dev->vcc = devm_regulator_get_optional(&client->dev,
> > "vcc");
>
> You you used regular devm_regulator_get(), you could remove the error
> handling below. If there's no regulator, you'll simply get a dummy
> one.

ok thanks


>
> > +       if (IS_ERR(dw9714_dev->vcc)) {
> > +               dev_dbg(&client->dev, "No vcc regulator found:
> > %ld\n",
> > +                       PTR_ERR(dw9714_dev->vcc));
> > +               dw9714_dev->vcc = NULL;
> > +       }
> > +
> > +       if (dw9714_dev->vcc) {
>
> With (dummy) regulators, these checks become unnecessary.
>
> > +               rval = regulator_enable(dw9714_dev->vcc);
> > +               if (rval < 0) {
> > +                       dev_err(&client->dev, "failed to enable
> > vcc: %d\n", rval);
> > +                       return rval;
> > +               }
> > +       }
> > +
> >         v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
> >         dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> >                                 V4L2_SUBDEV_FL_HAS_EVENTS;
> > @@ -200,6 +217,9 @@ static int __maybe_unused
> > dw9714_vcm_suspend(struct device *dev)
> >         struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
> >         int ret, val;
> >  
> > +       if (pm_runtime_suspended(&client->dev))
> > +               return 0;
>
> This can't take place in a runtime PM suspend callback. You'll need
> to add
> system suspend callback for this.

but this function is both the system and runtime suspend callback.
doesn't splitting up the callbacks just add lines of code
unnecessarily?

>
> > +
> >         for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS -
> > 1);
> >              val >= 0; val -= DW9714_CTRL_STEPS) {
> >                 ret = dw9714_i2c_write(client,
> > @@ -208,6 +228,13 @@ static int __maybe_unused
> > dw9714_vcm_suspend(struct device *dev)
> >                         dev_err_once(dev, "%s I2C failure: %d",
> > __func__, ret);
> >                 usleep_range(DW9714_CTRL_DELAY_US,
> > DW9714_CTRL_DELAY_US + 10);
> >         }
> > +
> > +       if (dw9714_dev->vcc) {
> > +               ret = regulator_disable(dw9714_dev->vcc);
> > +               if (ret)
> > +                       dev_err(dev, "Failed to disable vcc: %d\n",
> > ret);
> > +       }
> > +
> >         return 0;
> >  }
> >  
> > @@ -224,6 +251,18 @@ static int  __maybe_unused
> > dw9714_vcm_resume(struct device *dev)
> >         struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
> >         int ret, val;
> >  
> > +       if (pm_runtime_suspended(&client->dev))
>
> Same for this one.
>
> > +               return 0;
> > +
> > +       if (dw9714_dev->vcc) {
> > +               ret = regulator_enable(dw9714_dev->vcc);
> > +               if (ret) {
> > +                       dev_err(dev, "Failed to enable vcc: %d\n",
> > ret);
> > +                       return ret;
> > +               }
> > +               usleep_range(1000, 2000);
> > +       }
> > +
> >         for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
> >              val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
> >              val += DW9714_CTRL_STEPS) {
>



2021-11-26 12:31:27

by Sakari Ailus

[permalink] [raw]
Subject: Re: [PATCH v2] media: i2c: dw9714: add optional regulator support

On Fri, Nov 26, 2021 at 12:06:03PM +0100, Martin Kepplinger wrote:
> Am Freitag, dem 26.11.2021 um 12:44 +0200 schrieb Sakari Ailus:
> > Hi Martin,
> >
> > On Fri, Nov 26, 2021 at 10:01:07AM +0100, Martin Kepplinger wrote:
> > > From: Angus Ainslie <[email protected]>
> > >
> > > Allow the dw9714 to control a regulator and adjust suspend() and
> > > resume()
> > > to support both runtime and system pm.
> > >
> > > Signed-off-by: Angus Ainslie <[email protected]>
> > > Signed-off-by: Martin Kepplinger <[email protected]>
> > > ---
> > >
> > > revision history
> > > ----------------
> > >
> > > v2: (thank you Mark)
> > > ?* simplify the regulator_get_optional() error path
> > > ?* fix regulator usage during probe()
> > >
> > > v1:
> > > https://lore.kernel.org/linux-media/[email protected]/
> > >
> > >
> > >
> > > ?drivers/media/i2c/dw9714.c | 39
> > > ++++++++++++++++++++++++++++++++++++++
> > > ?1 file changed, 39 insertions(+)
> > >
> > > diff --git a/drivers/media/i2c/dw9714.c
> > > b/drivers/media/i2c/dw9714.c
> > > index 3863dfeb8293..e8cc19b89861 100644
> > > --- a/drivers/media/i2c/dw9714.c
> > > +++ b/drivers/media/i2c/dw9714.c
> > > @@ -5,6 +5,7 @@
> > > ?#include <linux/i2c.h>
> > > ?#include <linux/module.h>
> > > ?#include <linux/pm_runtime.h>
> > > +#include <linux/regulator/consumer.h>
> > > ?#include <media/v4l2-ctrls.h>
> > > ?#include <media/v4l2-device.h>
> > > ?#include <media/v4l2-event.h>
> > > @@ -36,6 +37,7 @@ struct dw9714_device {
> > > ????????struct v4l2_ctrl_handler ctrls_vcm;
> > > ????????struct v4l2_subdev sd;
> > > ????????u16 current_val;
> > > +???????struct regulator *vcc;
> > > ?};
> > > ?
> > > ?static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl
> > > *ctrl)
> > > @@ -145,6 +147,21 @@ static int dw9714_probe(struct i2c_client
> > > *client)
> > > ????????if (dw9714_dev == NULL)
> > > ????????????????return -ENOMEM;
> > > ?
> > > +???????dw9714_dev->vcc = devm_regulator_get_optional(&client->dev,
> > > "vcc");
> >
> > You you used regular devm_regulator_get(), you could remove the error
> > handling below. If there's no regulator, you'll simply get a dummy
> > one.
>
> ok thanks
>
>
> >
> > > +???????if (IS_ERR(dw9714_dev->vcc)) {
> > > +???????????????dev_dbg(&client->dev, "No vcc regulator found:
> > > %ld\n",
> > > +???????????????????????PTR_ERR(dw9714_dev->vcc));
> > > +???????????????dw9714_dev->vcc = NULL;
> > > +???????}
> > > +
> > > +???????if (dw9714_dev->vcc) {
> >
> > With (dummy) regulators, these checks become unnecessary.
> >
> > > +???????????????rval = regulator_enable(dw9714_dev->vcc);
> > > +???????????????if (rval < 0) {
> > > +???????????????????????dev_err(&client->dev, "failed to enable
> > > vcc: %d\n", rval);
> > > +???????????????????????return rval;
> > > +???????????????}
> > > +???????}
> > > +
> > > ????????v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
> > > ????????dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> > > ????????????????????????????????V4L2_SUBDEV_FL_HAS_EVENTS;
> > > @@ -200,6 +217,9 @@ static int __maybe_unused
> > > dw9714_vcm_suspend(struct device *dev)
> > > ????????struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
> > > ????????int ret, val;
> > > ?
> > > +???????if (pm_runtime_suspended(&client->dev))
> > > +???????????????return 0;
> >
> > This can't take place in a runtime PM suspend callback. You'll need
> > to add
> > system suspend callback for this.
>
> but this function is both the system and runtime suspend callback.
> doesn't splitting up the callbacks just add lines of code
> unnecessarily?

Hmm. After thinking about this a little, I think this could indeed work.

Yeah, please leave it as-is.

>
> >
> > > +
> > > ????????for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS -
> > > 1);
> > > ???????????? val >= 0; val -= DW9714_CTRL_STEPS) {
> > > ????????????????ret = dw9714_i2c_write(client,
> > > @@ -208,6 +228,13 @@ static int __maybe_unused
> > > dw9714_vcm_suspend(struct device *dev)
> > > ????????????????????????dev_err_once(dev, "%s I2C failure: %d",
> > > __func__, ret);
> > > ????????????????usleep_range(DW9714_CTRL_DELAY_US,
> > > DW9714_CTRL_DELAY_US + 10);
> > > ????????}
> > > +
> > > +???????if (dw9714_dev->vcc) {
> > > +???????????????ret = regulator_disable(dw9714_dev->vcc);
> > > +???????????????if (ret)
> > > +???????????????????????dev_err(dev, "Failed to disable vcc: %d\n",
> > > ret);
> > > +???????}
> > > +
> > > ????????return 0;
> > > ?}
> > > ?
> > > @@ -224,6 +251,18 @@ static int? __maybe_unused
> > > dw9714_vcm_resume(struct device *dev)
> > > ????????struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
> > > ????????int ret, val;
> > > ?
> > > +???????if (pm_runtime_suspended(&client->dev))
> >
> > Same for this one.
> >
> > > +???????????????return 0;
> > > +
> > > +???????if (dw9714_dev->vcc) {
> > > +???????????????ret = regulator_enable(dw9714_dev->vcc);
> > > +???????????????if (ret) {
> > > +???????????????????????dev_err(dev, "Failed to enable vcc: %d\n",
> > > ret);
> > > +???????????????????????return ret;
> > > +???????????????}
> > > +???????????????usleep_range(1000, 2000);
> > > +???????}
> > > +
> > > ????????for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
> > > ???????????? val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
> > > ???????????? val += DW9714_CTRL_STEPS) {
> >
>
>

--
Sakari Ailus

2021-11-26 13:07:16

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH v2] media: i2c: dw9714: add optional regulator support

On Fri, Nov 26, 2021 at 10:01:07AM +0100, Martin Kepplinger wrote:

> + dw9714_dev->vcc = devm_regulator_get_optional(&client->dev, "vcc");
> + if (IS_ERR(dw9714_dev->vcc)) {
> + dev_dbg(&client->dev, "No vcc regulator found: %ld\n",
> + PTR_ERR(dw9714_dev->vcc));
> + dw9714_dev->vcc = NULL;
> + }

To repeat my original feedback: unless the supply can be physically
absent you should use regulator_get(). The _optional variants are only
for cases where the supply might be physically absent.


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