diff mbox series

[4/4] media: hi556: Add support for avdd regulator

Message ID 20240201215841.153499-5-hdegoede@redhat.com (mailing list archive)
State Accepted
Headers
Series media: hi556: Add reset / clk / regulator support |

Commit Message

Hans de Goede Feb. 1, 2024, 9:58 p.m. UTC 
  On some ACPI platforms, such as Chromebooks the ACPI methods to
change the power-state (_PS0 and _PS3) fully take care of powering
on/off the sensor.

On other ACPI platforms, such as e.g. various HP models with IPU6 +
hi556 sensor, the sensor driver must control the avdd regulator itself.

Add support for having the driver control the sensor's avdd regulator.
Note this relies on the regulator-core providing a dummy regulator
(which it does by default) on platforms where Linux is not aware of
the avdd regulator.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/media/i2c/hi556.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

Comments

Jacopo Mondi Feb. 3, 2024, 10:15 a.m. UTC | #1 
Hi Hans

On Thu, Feb 01, 2024 at 10:58:41PM +0100, Hans de Goede wrote:
> On some ACPI platforms, such as Chromebooks the ACPI methods to
> change the power-state (_PS0 and _PS3) fully take care of powering
> on/off the sensor.
>
> On other ACPI platforms, such as e.g. various HP models with IPU6 +
> hi556 sensor, the sensor driver must control the avdd regulator itself.
>
> Add support for having the driver control the sensor's avdd regulator.
> Note this relies on the regulator-core providing a dummy regulator
> (which it does by default) on platforms where Linux is not aware of
> the avdd regulator.
>

Please excuse the question from an ACPI illiterate, but does it mean
that, in example:
1) Chromebooks: you get a dummy
2) HP: you get an actual regulator reference

> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/media/i2c/hi556.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c
> index fb6ba6984e38..90eff282a6e2 100644
> --- a/drivers/media/i2c/hi556.c
> +++ b/drivers/media/i2c/hi556.c
> @@ -9,6 +9,7 @@
>  #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-fwnode.h>
> @@ -638,6 +639,7 @@ struct hi556 {
>  	/* GPIOs, clocks, etc. */
>  	struct gpio_desc *reset_gpio;
>  	struct clk *clk;
> +	struct regulator *avdd;
>
>  	/* Current mode */
>  	const struct hi556_mode *cur_mode;
> @@ -1287,8 +1289,17 @@ static int hi556_suspend(struct device *dev)
>  {
>  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
>  	struct hi556 *hi556 = to_hi556(sd);
> +	int ret;
>
>  	gpiod_set_value_cansleep(hi556->reset_gpio, 1);
> +
> +	ret = regulator_disable(hi556->avdd);
> +	if (ret) {
> +		dev_err(dev, "failed to disable avdd: %d\n", ret);
> +		gpiod_set_value_cansleep(hi556->reset_gpio, 0);

I understand in error paths you're supposed to reverse the previously
done operations, but, as this is a reset, isn't it better to keep the
reset enabled since we're suspending anyway ?

> +		return ret;
> +	}
> +
>  	clk_disable_unprepare(hi556->clk);
>  	return 0;
>  }
> @@ -1303,6 +1314,13 @@ static int hi556_resume(struct device *dev)
>  	if (ret)
>  		return ret;
>
> +	ret = regulator_enable(hi556->avdd);
> +	if (ret) {
> +		dev_err(dev, "failed to enable avdd: %d\n", ret);
> +		clk_disable_unprepare(hi556->clk);
> +		return ret;
> +	}
> +
>  	gpiod_set_value_cansleep(hi556->reset_gpio, 0);
>  	usleep_range(5000, 5500);
>  	return 0;
> @@ -1338,6 +1356,12 @@ static int hi556_probe(struct i2c_client *client)
>  		return dev_err_probe(&client->dev, PTR_ERR(hi556->clk),
>  				     "failed to get clock\n");
>
> +	/* The regulator core will provide a "dummy" regulator if necessary */
> +	hi556->avdd = devm_regulator_get(&client->dev, "avdd");
> +	if (IS_ERR(hi556->avdd))
> +		return dev_err_probe(&client->dev, PTR_ERR(hi556->avdd),
> +				     "failed to get avdd regulator\n");
> +
>  	full_power = acpi_dev_state_d0(&client->dev);
>  	if (full_power) {
>  		/* Ensure non ACPI managed resources are enabled */
> --
> 2.43.0
>
>
Hans de Goede Feb. 3, 2024, 10:48 a.m. UTC | #2 
Hi,

On 2/3/24 11:15, Jacopo Mondi wrote:
> Hi Hans
> 
> On Thu, Feb 01, 2024 at 10:58:41PM +0100, Hans de Goede wrote:
>> On some ACPI platforms, such as Chromebooks the ACPI methods to
>> change the power-state (_PS0 and _PS3) fully take care of powering
>> on/off the sensor.
>>
>> On other ACPI platforms, such as e.g. various HP models with IPU6 +
>> hi556 sensor, the sensor driver must control the avdd regulator itself.
>>
>> Add support for having the driver control the sensor's avdd regulator.
>> Note this relies on the regulator-core providing a dummy regulator
>> (which it does by default) on platforms where Linux is not aware of
>> the avdd regulator.
>>
> 
> Please excuse the question from an ACPI illiterate, but does it mean
> that, in example:
> 1) Chromebooks: you get a dummy
> 2) HP: you get an actual regulator reference

Yes that is correct.

Regards,

Hans




> 
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  drivers/media/i2c/hi556.c | 24 ++++++++++++++++++++++++
>>  1 file changed, 24 insertions(+)
>>
>> diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c
>> index fb6ba6984e38..90eff282a6e2 100644
>> --- a/drivers/media/i2c/hi556.c
>> +++ b/drivers/media/i2c/hi556.c
>> @@ -9,6 +9,7 @@
>>  #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-fwnode.h>
>> @@ -638,6 +639,7 @@ struct hi556 {
>>  	/* GPIOs, clocks, etc. */
>>  	struct gpio_desc *reset_gpio;
>>  	struct clk *clk;
>> +	struct regulator *avdd;
>>
>>  	/* Current mode */
>>  	const struct hi556_mode *cur_mode;
>> @@ -1287,8 +1289,17 @@ static int hi556_suspend(struct device *dev)
>>  {
>>  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
>>  	struct hi556 *hi556 = to_hi556(sd);
>> +	int ret;
>>
>>  	gpiod_set_value_cansleep(hi556->reset_gpio, 1);
>> +
>> +	ret = regulator_disable(hi556->avdd);
>> +	if (ret) {
>> +		dev_err(dev, "failed to disable avdd: %d\n", ret);
>> +		gpiod_set_value_cansleep(hi556->reset_gpio, 0);
> 
> I understand in error paths you're supposed to reverse the previously
> done operations, but, as this is a reset, isn't it better to keep the
> reset enabled since we're suspending anyway ?
> 
>> +		return ret;
>> +	}
>> +
>>  	clk_disable_unprepare(hi556->clk);
>>  	return 0;
>>  }
>> @@ -1303,6 +1314,13 @@ static int hi556_resume(struct device *dev)
>>  	if (ret)
>>  		return ret;
>>
>> +	ret = regulator_enable(hi556->avdd);
>> +	if (ret) {
>> +		dev_err(dev, "failed to enable avdd: %d\n", ret);
>> +		clk_disable_unprepare(hi556->clk);
>> +		return ret;
>> +	}
>> +
>>  	gpiod_set_value_cansleep(hi556->reset_gpio, 0);
>>  	usleep_range(5000, 5500);
>>  	return 0;
>> @@ -1338,6 +1356,12 @@ static int hi556_probe(struct i2c_client *client)
>>  		return dev_err_probe(&client->dev, PTR_ERR(hi556->clk),
>>  				     "failed to get clock\n");
>>
>> +	/* The regulator core will provide a "dummy" regulator if necessary */
>> +	hi556->avdd = devm_regulator_get(&client->dev, "avdd");
>> +	if (IS_ERR(hi556->avdd))
>> +		return dev_err_probe(&client->dev, PTR_ERR(hi556->avdd),
>> +				     "failed to get avdd regulator\n");
>> +
>>  	full_power = acpi_dev_state_d0(&client->dev);
>>  	if (full_power) {
>>  		/* Ensure non ACPI managed resources are enabled */
>> --
>> 2.43.0
>>
>>
>
diff mbox series

Patch

diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c
index fb6ba6984e38..90eff282a6e2 100644
--- a/drivers/media/i2c/hi556.c
+++ b/drivers/media/i2c/hi556.c
@@ -9,6 +9,7 @@ 
 #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-fwnode.h>
@@ -638,6 +639,7 @@  struct hi556 {
 	/* GPIOs, clocks, etc. */
 	struct gpio_desc *reset_gpio;
 	struct clk *clk;
+	struct regulator *avdd;
 
 	/* Current mode */
 	const struct hi556_mode *cur_mode;
@@ -1287,8 +1289,17 @@  static int hi556_suspend(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct hi556 *hi556 = to_hi556(sd);
+	int ret;
 
 	gpiod_set_value_cansleep(hi556->reset_gpio, 1);
+
+	ret = regulator_disable(hi556->avdd);
+	if (ret) {
+		dev_err(dev, "failed to disable avdd: %d\n", ret);
+		gpiod_set_value_cansleep(hi556->reset_gpio, 0);
+		return ret;
+	}
+
 	clk_disable_unprepare(hi556->clk);
 	return 0;
 }
@@ -1303,6 +1314,13 @@  static int hi556_resume(struct device *dev)
 	if (ret)
 		return ret;
 
+	ret = regulator_enable(hi556->avdd);
+	if (ret) {
+		dev_err(dev, "failed to enable avdd: %d\n", ret);
+		clk_disable_unprepare(hi556->clk);
+		return ret;
+	}
+
 	gpiod_set_value_cansleep(hi556->reset_gpio, 0);
 	usleep_range(5000, 5500);
 	return 0;
@@ -1338,6 +1356,12 @@  static int hi556_probe(struct i2c_client *client)
 		return dev_err_probe(&client->dev, PTR_ERR(hi556->clk),
 				     "failed to get clock\n");
 
+	/* The regulator core will provide a "dummy" regulator if necessary */
+	hi556->avdd = devm_regulator_get(&client->dev, "avdd");
+	if (IS_ERR(hi556->avdd))
+		return dev_err_probe(&client->dev, PTR_ERR(hi556->avdd),
+				     "failed to get avdd regulator\n");
+
 	full_power = acpi_dev_state_d0(&client->dev);
 	if (full_power) {
 		/* Ensure non ACPI managed resources are enabled */