[4/4] media: hi556: Add support for avdd regulator
Commit Message
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
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
>
>
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
>>
>>
>
@@ -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 */