[PATCH v2 0/3] media: i2c: ak7375: Add regulator management

[PATCH v2 0/3] media: i2c: ak7375: Add regulator management

[Yassine Oudjana]

From: Yassine Oudjana <y.oudjana@protonmail.com>

This series adds needed regulator management for the AK7375 VCM.
A DT schema conversion is made before adding new properties.

Changes since v1:
  - Add vendor prefix to DT binding doc file name
  - Reorganize variable declaration
  - Change the power-on delay range to 3000-3500 microseconds.

Yassine Oudjana (3):
  media: dt-bindings: ak7375: Convert to DT schema
  media: dt-bindings: ak7375: Add supplies
  media: i2c: ak7375: Add regulator management

 .../devicetree/bindings/media/i2c/ak7375.txt  |  8 ---
 .../media/i2c/asahi-kasei,ak7375.yaml         | 52 +++++++++++++++++++
 MAINTAINERS                                   |  2 +-
 drivers/media/i2c/ak7375.c                    | 39 ++++++++++++++
 4 files changed, 92 insertions(+), 9 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.txt
 create mode 100644 Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml

-- 
2.37.0

[PATCH v2 1/3] media: dt-bindings: ak7375: Convert to DT schema

[Yassine Oudjana]

From: Yassine Oudjana <y.oudjana@protonmail.com>

Convert DT bindings document for AKM AK7375 VCM to DT schema
format and add an example.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
---
Changes since v1:
  - Add vendor prefix to DT binding doc file name

 .../devicetree/bindings/media/i2c/ak7375.txt  |  8 ----
 .../media/i2c/asahi-kasei,ak7375.yaml         | 41 +++++++++++++++++++
 MAINTAINERS                                   |  2 +-
 3 files changed, 42 insertions(+), 9 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.txt
 create mode 100644 Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/ak7375.txt b/Documentation/devicetree/bindings/media/i2c/ak7375.txt
deleted file mode 100644
index aa3e24b41241..000000000000
--- a/Documentation/devicetree/bindings/media/i2c/ak7375.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-Asahi Kasei Microdevices AK7375 voice coil lens driver
-
-AK7375 is a camera voice coil lens.
-
-Mandatory properties:
-
-- compatible: "asahi-kasei,ak7375"
-- reg: I2C slave address
diff --git a/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
new file mode 100644
index 000000000000..22b1251b16ee
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/asahi-kasei,ak7375.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Asahi Kasei Microdevices AK7375 voice coil lens actuator
+
+maintainers:
+  - Tianshu Qiu <tian.shu.qiu@intel.com>
+
+description:
+  AK7375 is a voice coil motor (VCM) camera lens actuator that
+  is controlled over I2C.
+
+properties:
+  compatible:
+    const: asahi-kasei,ak7375
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ak7375: camera-lens@c {
+            compatible = "asahi-kasei,ak7375";
+            reg = <0x0c>;
+        };
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index a97fef8c131d..e6accf8bc12b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3063,7 +3063,7 @@ M:	Tianshu Qiu <tian.shu.qiu@intel.com>
 L:	linux-media@vger.kernel.org
 S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
-F:	Documentation/devicetree/bindings/media/i2c/ak7375.txt
+F:	Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
 F:	drivers/media/i2c/ak7375.c
 
 ASAHI KASEI AK8974 DRIVER
-- 
2.37.0

[PATCH v2 2/3] media: dt-bindings: ak7375: Add supplies

[Yassine Oudjana]

From: Yassine Oudjana <y.oudjana@protonmail.com>

Add supply properties to describe regulators needed to power
the AK7375 VCM.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../bindings/media/i2c/asahi-kasei,ak7375.yaml        | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
index 22b1251b16ee..22a810fc7222 100644
--- a/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
+++ b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
@@ -20,9 +20,17 @@ properties:
   reg:
     maxItems: 1
 
+  vdd-supply:
+    description: VDD supply
+
+  vio-supply:
+    description: I/O pull-up supply
+
 required:
   - compatible
   - reg
+  - vdd-supply
+  - vio-supply
 
 additionalProperties: false
 
@@ -35,6 +43,9 @@ examples:
         ak7375: camera-lens@c {
             compatible = "asahi-kasei,ak7375";
             reg = <0x0c>;
+
+            vdd-supply = <&vreg_l23a_2p8>;
+            vio-supply = <&vreg_lvs1a_1p8>;
         };
     };
 
-- 
2.37.0

[PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Yassine Oudjana]

From: Yassine Oudjana <y.oudjana@protonmail.com>

Make the driver get needed regulators on probe and enable/disable
them on runtime PM callbacks.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
---
Changes since v1:
  - Reorganize variable declaration
  - Change the power-on delay range to 3000-3500 microseconds.

 drivers/media/i2c/ak7375.c | 39 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
index 40b1a4aa846c..c2b2542a0056 100644
--- a/drivers/media/i2c/ak7375.c
+++ b/drivers/media/i2c/ak7375.c
@@ -6,6 +6,7 @@
 #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>
 
@@ -23,17 +24,32 @@
  */
 #define AK7375_CTRL_STEPS	64
 #define AK7375_CTRL_DELAY_US	1000
+/*
+ * The vcm takes around 3 ms to power on and start taking
+ * I2C messages. This value was found experimentally due to
+ * lack of documentation.
+ */
+#define AK7375_POWER_DELAY_US	3000
 
 #define AK7375_REG_POSITION	0x0
 #define AK7375_REG_CONT		0x2
 #define AK7375_MODE_ACTIVE	0x0
 #define AK7375_MODE_STANDBY	0x40
 
+static const char * const ak7375_supply_names[] = {
+	"vdd",
+	"vio",
+};
+
+#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
+
 /* ak7375 device structure */
 struct ak7375_device {
 	struct v4l2_ctrl_handler ctrls_vcm;
 	struct v4l2_subdev sd;
 	struct v4l2_ctrl *focus;
+	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
+
 	/* active or standby mode */
 	bool active;
 };
@@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client *client)
 {
 	struct ak7375_device *ak7375_dev;
 	int ret;
+	int i;
 
 	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
 				  GFP_KERNEL);
 	if (!ak7375_dev)
 		return -ENOMEM;
 
+	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
+		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
+
+	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
+				      ak7375_dev->supplies);
+	if (ret) {
+		dev_err(&client->dev, "Failed to get regulators: %pe",
+			ERR_PTR(ret));
+		return ret;
+	}
+
 	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
 	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
@@ -210,6 +238,10 @@ static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
 	if (ret)
 		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
 
+	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
+	if (ret)
+		return ret;
+
 	ak7375_dev->active = false;
 
 	return 0;
@@ -230,6 +262,13 @@ static int __maybe_unused ak7375_vcm_resume(struct device *dev)
 	if (ak7375_dev->active)
 		return 0;
 
+	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
+	if (ret)
+		return ret;
+
+	/* Wait for vcm to become ready */
+	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
+
 	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
 		AK7375_MODE_ACTIVE, 1);
 	if (ret) {
-- 
2.37.0

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Jacopo Mondi]

Hi Yassine,

On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
>
> Make the driver get needed regulators on probe and enable/disable
> them on runtime PM callbacks.
>
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> ---
> Changes since v1:
>   - Reorganize variable declaration
>   - Change the power-on delay range to 3000-3500 microseconds.
>
>  drivers/media/i2c/ak7375.c | 39 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>
> diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
> index 40b1a4aa846c..c2b2542a0056 100644
> --- a/drivers/media/i2c/ak7375.c
> +++ b/drivers/media/i2c/ak7375.c
> @@ -6,6 +6,7 @@
>  #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>
>
> @@ -23,17 +24,32 @@
>   */
>  #define AK7375_CTRL_STEPS	64
>  #define AK7375_CTRL_DELAY_US	1000
> +/*
> + * The vcm takes around 3 ms to power on and start taking
> + * I2C messages. This value was found experimentally due to
> + * lack of documentation.
> + */
> +#define AK7375_POWER_DELAY_US	3000
>
>  #define AK7375_REG_POSITION	0x0
>  #define AK7375_REG_CONT		0x2
>  #define AK7375_MODE_ACTIVE	0x0
>  #define AK7375_MODE_STANDBY	0x40
>
> +static const char * const ak7375_supply_names[] = {
> +	"vdd",
> +	"vio",
> +};
> +
> +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
> +
>  /* ak7375 device structure */
>  struct ak7375_device {
>  	struct v4l2_ctrl_handler ctrls_vcm;
>  	struct v4l2_subdev sd;
>  	struct v4l2_ctrl *focus;
> +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
> +
>  	/* active or standby mode */
>  	bool active;
>  };
> @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client *client)
>  {
>  	struct ak7375_device *ak7375_dev;
>  	int ret;
> +	int i;
>
>  	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
>  				  GFP_KERNEL);
>  	if (!ak7375_dev)
>  		return -ENOMEM;
>
> +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
> +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
> +
> +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
> +				      ak7375_dev->supplies);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to get regulators: %pe",
> +			ERR_PTR(ret));

Why are you using %pe here ? Your return value is not a pointer
(Also, missing \n at the end of the string)

From Documentation/core-api/printk-formats.rst:
	%pe	-ENOSPC

For printing error pointers (i.e. a pointer for which IS_ERR() is true)
as a symbolic error name. Error values for which no symbolic name is
known are printed in decimal, while a non-ERR_PTR passed as the
argument to %pe gets treated as ordinary %p.

> +		return ret;
> +	}
> +
>  	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
>  	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>  	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
> @@ -210,6 +238,10 @@ static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
>  	if (ret)
>  		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
>
> +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
> +	if (ret)
> +		return ret;
> +
>  	ak7375_dev->active = false;
>
>  	return 0;
> @@ -230,6 +262,13 @@ static int __maybe_unused ak7375_vcm_resume(struct device *dev)
>  	if (ak7375_dev->active)
>  		return 0;
>
> +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
> +	if (ret)
> +		return ret;
> +
> +	/* Wait for vcm to become ready */
> +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
> +
>  	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
>  		AK7375_MODE_ACTIVE, 1);
>  	if (ret) {
> --
> 2.37.0
>

Re: [PATCH v2 1/3] media: dt-bindings: ak7375: Convert to DT schema

[Krzysztof Kozlowski]

On 11/07/2022 16:40, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
> 
> Convert DT bindings document for AKM AK7375 VCM to DT schema
> format and add an example.
> 
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


Best regards,
Krzysztof

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Jacopo Mondi]

Hi Yassine

On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
>
> Make the driver get needed regulators on probe and enable/disable
> them on runtime PM callbacks.
>
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>

Have you seen this ?
https://github.com/ArduCAM/IMX519_AK7375/blob/main/AK7375/0002-media-i2c-ak7375-driver-add-optional-regulator-suppo.patch#L172

It claims
+	* Initialisation delay between VDD low->high and the moment
+	* when the i2c command is available.
+	* From the datasheet, it should be 10ms + 2ms (max power
+	* up sequence duration)

10ms seems like a long time, it would be nice to have the datasheet to
cross-check.

Thanks
   j

> ---
> Changes since v1:
>   - Reorganize variable declaration
>   - Change the power-on delay range to 3000-3500 microseconds.
>
>  drivers/media/i2c/ak7375.c | 39 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>
> diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
> index 40b1a4aa846c..c2b2542a0056 100644
> --- a/drivers/media/i2c/ak7375.c
> +++ b/drivers/media/i2c/ak7375.c
> @@ -6,6 +6,7 @@
>  #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>
>
> @@ -23,17 +24,32 @@
>   */
>  #define AK7375_CTRL_STEPS	64
>  #define AK7375_CTRL_DELAY_US	1000
> +/*
> + * The vcm takes around 3 ms to power on and start taking
> + * I2C messages. This value was found experimentally due to
> + * lack of documentation.
> + */
> +#define AK7375_POWER_DELAY_US	3000
>
>  #define AK7375_REG_POSITION	0x0
>  #define AK7375_REG_CONT		0x2
>  #define AK7375_MODE_ACTIVE	0x0
>  #define AK7375_MODE_STANDBY	0x40
>
> +static const char * const ak7375_supply_names[] = {
> +	"vdd",
> +	"vio",
> +};
> +
> +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
> +
>  /* ak7375 device structure */
>  struct ak7375_device {
>  	struct v4l2_ctrl_handler ctrls_vcm;
>  	struct v4l2_subdev sd;
>  	struct v4l2_ctrl *focus;
> +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
> +
>  	/* active or standby mode */
>  	bool active;
>  };
> @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client *client)
>  {
>  	struct ak7375_device *ak7375_dev;
>  	int ret;
> +	int i;
>
>  	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
>  				  GFP_KERNEL);
>  	if (!ak7375_dev)
>  		return -ENOMEM;
>
> +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
> +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
> +
> +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
> +				      ak7375_dev->supplies);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to get regulators: %pe",
> +			ERR_PTR(ret));
> +		return ret;
> +	}
> +
>  	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
>  	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>  	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
> @@ -210,6 +238,10 @@ static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
>  	if (ret)
>  		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
>
> +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
> +	if (ret)
> +		return ret;
> +
>  	ak7375_dev->active = false;
>
>  	return 0;
> @@ -230,6 +262,13 @@ static int __maybe_unused ak7375_vcm_resume(struct device *dev)
>  	if (ak7375_dev->active)
>  		return 0;
>
> +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
> +	if (ret)
> +		return ret;
> +
> +	/* Wait for vcm to become ready */
> +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
> +
>  	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
>  		AK7375_MODE_ACTIVE, 1);
>  	if (ret) {
> --
> 2.37.0
>

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Yassine Oudjana]

On Mon, Jul 11 2022 at 19:31:23 +0200, Jacopo Mondi <jacopo@jmondi.org> 
wrote:
> Hi Yassine,
> 
> On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
>>  From: Yassine Oudjana <y.oudjana@protonmail.com>
>> 
>>  Make the driver get needed regulators on probe and enable/disable
>>  them on runtime PM callbacks.
>> 
>>  Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
>>  ---
>>  Changes since v1:
>>    - Reorganize variable declaration
>>    - Change the power-on delay range to 3000-3500 microseconds.
>> 
>>   drivers/media/i2c/ak7375.c | 39 
>> ++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 39 insertions(+)
>> 
>>  diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
>>  index 40b1a4aa846c..c2b2542a0056 100644
>>  --- a/drivers/media/i2c/ak7375.c
>>  +++ b/drivers/media/i2c/ak7375.c
>>  @@ -6,6 +6,7 @@
>>   #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>
>> 
>>  @@ -23,17 +24,32 @@
>>    */
>>   #define AK7375_CTRL_STEPS	64
>>   #define AK7375_CTRL_DELAY_US	1000
>>  +/*
>>  + * The vcm takes around 3 ms to power on and start taking
>>  + * I2C messages. This value was found experimentally due to
>>  + * lack of documentation.
>>  + */
>>  +#define AK7375_POWER_DELAY_US	3000
>> 
>>   #define AK7375_REG_POSITION	0x0
>>   #define AK7375_REG_CONT		0x2
>>   #define AK7375_MODE_ACTIVE	0x0
>>   #define AK7375_MODE_STANDBY	0x40
>> 
>>  +static const char * const ak7375_supply_names[] = {
>>  +	"vdd",
>>  +	"vio",
>>  +};
>>  +
>>  +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
>>  +
>>   /* ak7375 device structure */
>>   struct ak7375_device {
>>   	struct v4l2_ctrl_handler ctrls_vcm;
>>   	struct v4l2_subdev sd;
>>   	struct v4l2_ctrl *focus;
>>  +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
>>  +
>>   	/* active or standby mode */
>>   	bool active;
>>   };
>>  @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client 
>> *client)
>>   {
>>   	struct ak7375_device *ak7375_dev;
>>   	int ret;
>>  +	int i;
>> 
>>   	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
>>   				  GFP_KERNEL);
>>   	if (!ak7375_dev)
>>   		return -ENOMEM;
>> 
>>  +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
>>  +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
>>  +
>>  +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
>>  +				      ak7375_dev->supplies);
>>  +	if (ret) {
>>  +		dev_err(&client->dev, "Failed to get regulators: %pe",
>>  +			ERR_PTR(ret));
> 
> Why are you using %pe here ? Your return value is not a pointer

In order to have it print a symbolic error name instead of a value
with CONFIG_SYMBOLIC_ERRNAME=y. There is no format code for an
error integer (or at least I couldn't find one mentioned anywhere
in the docs), so instead I use %pe then wrap `ret` in ERR_PTR().

> (Also, missing \n at the end of the string)

That wasn't intentional. I'll fix it.

> 
> From Documentation/core-api/printk-formats.rst:
> 	%pe	-ENOSPC
> 
> For printing error pointers (i.e. a pointer for which IS_ERR() is 
> true)
> as a symbolic error name. Error values for which no symbolic name is
> known are printed in decimal, while a non-ERR_PTR passed as the
> argument to %pe gets treated as ordinary %p.
> 
>>  +		return ret;
>>  +	}
>>  +
>>   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
>>   	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>   	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
>>  @@ -210,6 +238,10 @@ static int __maybe_unused 
>> ak7375_vcm_suspend(struct device *dev)
>>   	if (ret)
>>   		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
>> 
>>  +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, 
>> ak7375_dev->supplies);
>>  +	if (ret)
>>  +		return ret;
>>  +
>>   	ak7375_dev->active = false;
>> 
>>   	return 0;
>>  @@ -230,6 +262,13 @@ static int __maybe_unused 
>> ak7375_vcm_resume(struct device *dev)
>>   	if (ak7375_dev->active)
>>   		return 0;
>> 
>>  +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, 
>> ak7375_dev->supplies);
>>  +	if (ret)
>>  +		return ret;
>>  +
>>  +	/* Wait for vcm to become ready */
>>  +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
>>  +
>>   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
>>   		AK7375_MODE_ACTIVE, 1);
>>   	if (ret) {
>>  --
>>  2.37.0
>> 

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Yassine Oudjana]

On Wed, Jul 13 2022 at 09:39:51 +0200, Jacopo Mondi <jacopo@jmondi.org> 
wrote:
> Hi Yassine
> 
> On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
>>  From: Yassine Oudjana <y.oudjana@protonmail.com>
>> 
>>  Make the driver get needed regulators on probe and enable/disable
>>  them on runtime PM callbacks.
>> 
>>  Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> 
> Have you seen this ?
> https://github.com/ArduCAM/IMX519_AK7375/blob/main/AK7375/0002-media-i2c-ak7375-driver-add-optional-regulator-suppo.patch#L172
> 
> It claims
> +	* Initialisation delay between VDD low->high and the moment
> +	* when the i2c command is available.
> +	* From the datasheet, it should be 10ms + 2ms (max power
> +	* up sequence duration)
> 
> 10ms seems like a long time, it would be nice to have the datasheet to
> cross-check.

It does seem quite long. I couldn't find a datasheet anywhere
so the value I discovered is the best I have. I've added the
author of that patch to CC; maybe they have some info to
contribute.

> 
> Thanks
>    j
> 
>>  ---
>>  Changes since v1:
>>    - Reorganize variable declaration
>>    - Change the power-on delay range to 3000-3500 microseconds.
>> 
>>   drivers/media/i2c/ak7375.c | 39 
>> ++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 39 insertions(+)
>> 
>>  diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
>>  index 40b1a4aa846c..c2b2542a0056 100644
>>  --- a/drivers/media/i2c/ak7375.c
>>  +++ b/drivers/media/i2c/ak7375.c
>>  @@ -6,6 +6,7 @@
>>   #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>
>> 
>>  @@ -23,17 +24,32 @@
>>    */
>>   #define AK7375_CTRL_STEPS	64
>>   #define AK7375_CTRL_DELAY_US	1000
>>  +/*
>>  + * The vcm takes around 3 ms to power on and start taking
>>  + * I2C messages. This value was found experimentally due to
>>  + * lack of documentation.
>>  + */
>>  +#define AK7375_POWER_DELAY_US	3000
>> 
>>   #define AK7375_REG_POSITION	0x0
>>   #define AK7375_REG_CONT		0x2
>>   #define AK7375_MODE_ACTIVE	0x0
>>   #define AK7375_MODE_STANDBY	0x40
>> 
>>  +static const char * const ak7375_supply_names[] = {
>>  +	"vdd",
>>  +	"vio",
>>  +};
>>  +
>>  +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
>>  +
>>   /* ak7375 device structure */
>>   struct ak7375_device {
>>   	struct v4l2_ctrl_handler ctrls_vcm;
>>   	struct v4l2_subdev sd;
>>   	struct v4l2_ctrl *focus;
>>  +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
>>  +
>>   	/* active or standby mode */
>>   	bool active;
>>   };
>>  @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client 
>> *client)
>>   {
>>   	struct ak7375_device *ak7375_dev;
>>   	int ret;
>>  +	int i;
>> 
>>   	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
>>   				  GFP_KERNEL);
>>   	if (!ak7375_dev)
>>   		return -ENOMEM;
>> 
>>  +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
>>  +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
>>  +
>>  +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
>>  +				      ak7375_dev->supplies);
>>  +	if (ret) {
>>  +		dev_err(&client->dev, "Failed to get regulators: %pe",
>>  +			ERR_PTR(ret));
>>  +		return ret;
>>  +	}
>>  +
>>   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
>>   	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>   	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
>>  @@ -210,6 +238,10 @@ static int __maybe_unused 
>> ak7375_vcm_suspend(struct device *dev)
>>   	if (ret)
>>   		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
>> 
>>  +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, 
>> ak7375_dev->supplies);
>>  +	if (ret)
>>  +		return ret;
>>  +
>>   	ak7375_dev->active = false;
>> 
>>   	return 0;
>>  @@ -230,6 +262,13 @@ static int __maybe_unused 
>> ak7375_vcm_resume(struct device *dev)
>>   	if (ak7375_dev->active)
>>   		return 0;
>> 
>>  +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, 
>> ak7375_dev->supplies);
>>  +	if (ret)
>>  +		return ret;
>>  +
>>  +	/* Wait for vcm to become ready */
>>  +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
>>  +
>>   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
>>   		AK7375_MODE_ACTIVE, 1);
>>   	if (ret) {
>>  --
>>  2.37.0
>> 

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Jacopo Mondi]

Hi Yassine,

On Thu, Jul 14, 2022 at 05:56:29PM +0400, Yassine Oudjana wrote:
>
> On Mon, Jul 11 2022 at 19:31:23 +0200, Jacopo Mondi <jacopo@jmondi.org>
> wrote:
> > Hi Yassine,
> >
> > On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
> > >  From: Yassine Oudjana <y.oudjana@protonmail.com>
> > >
> > >  Make the driver get needed regulators on probe and enable/disable
> > >  them on runtime PM callbacks.
> > >
> > >  Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> > >  ---
> > >  Changes since v1:
> > >    - Reorganize variable declaration
> > >    - Change the power-on delay range to 3000-3500 microseconds.
> > >
> > >   drivers/media/i2c/ak7375.c | 39
> > > ++++++++++++++++++++++++++++++++++++++
> > >   1 file changed, 39 insertions(+)
> > >
> > >  diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
> > >  index 40b1a4aa846c..c2b2542a0056 100644
> > >  --- a/drivers/media/i2c/ak7375.c
> > >  +++ b/drivers/media/i2c/ak7375.c
> > >  @@ -6,6 +6,7 @@
> > >   #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>
> > >
> > >  @@ -23,17 +24,32 @@
> > >    */
> > >   #define AK7375_CTRL_STEPS	64
> > >   #define AK7375_CTRL_DELAY_US	1000
> > >  +/*
> > >  + * The vcm takes around 3 ms to power on and start taking
> > >  + * I2C messages. This value was found experimentally due to
> > >  + * lack of documentation.
> > >  + */
> > >  +#define AK7375_POWER_DELAY_US	3000
> > >
> > >   #define AK7375_REG_POSITION	0x0
> > >   #define AK7375_REG_CONT		0x2
> > >   #define AK7375_MODE_ACTIVE	0x0
> > >   #define AK7375_MODE_STANDBY	0x40
> > >
> > >  +static const char * const ak7375_supply_names[] = {
> > >  +	"vdd",
> > >  +	"vio",
> > >  +};
> > >  +
> > >  +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
> > >  +
> > >   /* ak7375 device structure */
> > >   struct ak7375_device {
> > >   	struct v4l2_ctrl_handler ctrls_vcm;
> > >   	struct v4l2_subdev sd;
> > >   	struct v4l2_ctrl *focus;
> > >  +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
> > >  +
> > >   	/* active or standby mode */
> > >   	bool active;
> > >   };
> > >  @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client
> > > *client)
> > >   {
> > >   	struct ak7375_device *ak7375_dev;
> > >   	int ret;
> > >  +	int i;
> > >
> > >   	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
> > >   				  GFP_KERNEL);
> > >   	if (!ak7375_dev)
> > >   		return -ENOMEM;
> > >
> > >  +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
> > >  +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
> > >  +
> > >  +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
> > >  +				      ak7375_dev->supplies);
> > >  +	if (ret) {
> > >  +		dev_err(&client->dev, "Failed to get regulators: %pe",
> > >  +			ERR_PTR(ret));
> >
> > Why are you using %pe here ? Your return value is not a pointer
>
> In order to have it print a symbolic error name instead of a value
> with CONFIG_SYMBOLIC_ERRNAME=y. There is no format code for an
> error integer (or at least I couldn't find one mentioned anywhere
> in the docs), so instead I use %pe then wrap `ret` in ERR_PTR().
>

Ah nice, sorry I didn't realize. I grepped around in drivers/media and
saw it only used with pointer values, but I actually missed two
drivers that wrap ret in ERR_PTR() like you're doing here.

> > (Also, missing \n at the end of the string)
>
> That wasn't intentional. I'll fix it.
>

That's indeed minor.
Let me reply to the other email about delays..


> >
> > From Documentation/core-api/printk-formats.rst:
> > 	%pe	-ENOSPC
> >
> > For printing error pointers (i.e. a pointer for which IS_ERR() is true)
> > as a symbolic error name. Error values for which no symbolic name is
> > known are printed in decimal, while a non-ERR_PTR passed as the
> > argument to %pe gets treated as ordinary %p.
> >
> > >  +		return ret;
> > >  +	}
> > >  +
> > >   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
> > >   	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > >   	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
> > >  @@ -210,6 +238,10 @@ static int __maybe_unused
> > > ak7375_vcm_suspend(struct device *dev)
> > >   	if (ret)
> > >   		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
> > >
> > >  +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES,
> > > ak7375_dev->supplies);
> > >  +	if (ret)
> > >  +		return ret;
> > >  +
> > >   	ak7375_dev->active = false;
> > >
> > >   	return 0;
> > >  @@ -230,6 +262,13 @@ static int __maybe_unused
> > > ak7375_vcm_resume(struct device *dev)
> > >   	if (ak7375_dev->active)
> > >   		return 0;
> > >
> > >  +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES,
> > > ak7375_dev->supplies);
> > >  +	if (ret)
> > >  +		return ret;
> > >  +
> > >  +	/* Wait for vcm to become ready */
> > >  +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
> > >  +
> > >   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
> > >   		AK7375_MODE_ACTIVE, 1);
> > >   	if (ret) {
> > >  --
> > >  2.37.0
> > >
>
>

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Jacopo Mondi]

Hello Yassine

On Thu, Jul 14, 2022 at 06:06:32PM +0400, Yassine Oudjana wrote:
>
> On Wed, Jul 13 2022 at 09:39:51 +0200, Jacopo Mondi <jacopo@jmondi.org>
> wrote:
> > Hi Yassine
> >
> > On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
> > >  From: Yassine Oudjana <y.oudjana@protonmail.com>
> > >
> > >  Make the driver get needed regulators on probe and enable/disable
> > >  them on runtime PM callbacks.
> > >
> > >  Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> >
> > Have you seen this ?
> > https://github.com/ArduCAM/IMX519_AK7375/blob/main/AK7375/0002-media-i2c-ak7375-driver-add-optional-regulator-suppo.patch#L172
> >
> > It claims
> > +	* Initialisation delay between VDD low->high and the moment
> > +	* when the i2c command is available.
> > +	* From the datasheet, it should be 10ms + 2ms (max power
> > +	* up sequence duration)
> >
> > 10ms seems like a long time, it would be nice to have the datasheet to
> > cross-check.
>
> It does seem quite long. I couldn't find a datasheet anywhere
> so the value I discovered is the best I have. I've added the
> author of that patch to CC; maybe they have some info to
> contribute.
>

I have now tested these patches with an Arducam IMX519 camera.
Using a 3msec delay I get failures in the establishing i2c
communications (I only tested 2 times though).

With 10milliseconds (which I concur is a lot) I get stable results.
Let's see if we can get more info from who has the manual.

Thanks
  j

> >
> > Thanks
> >    j
> >
> > >  ---
> > >  Changes since v1:
> > >    - Reorganize variable declaration
> > >    - Change the power-on delay range to 3000-3500 microseconds.
> > >
> > >   drivers/media/i2c/ak7375.c | 39
> > > ++++++++++++++++++++++++++++++++++++++
> > >   1 file changed, 39 insertions(+)
> > >
> > >  diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
> > >  index 40b1a4aa846c..c2b2542a0056 100644
> > >  --- a/drivers/media/i2c/ak7375.c
> > >  +++ b/drivers/media/i2c/ak7375.c
> > >  @@ -6,6 +6,7 @@
> > >   #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>
> > >
> > >  @@ -23,17 +24,32 @@
> > >    */
> > >   #define AK7375_CTRL_STEPS	64
> > >   #define AK7375_CTRL_DELAY_US	1000
> > >  +/*
> > >  + * The vcm takes around 3 ms to power on and start taking
> > >  + * I2C messages. This value was found experimentally due to
> > >  + * lack of documentation.
> > >  + */
> > >  +#define AK7375_POWER_DELAY_US	3000
> > >
> > >   #define AK7375_REG_POSITION	0x0
> > >   #define AK7375_REG_CONT		0x2
> > >   #define AK7375_MODE_ACTIVE	0x0
> > >   #define AK7375_MODE_STANDBY	0x40
> > >
> > >  +static const char * const ak7375_supply_names[] = {
> > >  +	"vdd",
> > >  +	"vio",
> > >  +};
> > >  +
> > >  +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
> > >  +
> > >   /* ak7375 device structure */
> > >   struct ak7375_device {
> > >   	struct v4l2_ctrl_handler ctrls_vcm;
> > >   	struct v4l2_subdev sd;
> > >   	struct v4l2_ctrl *focus;
> > >  +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
> > >  +
> > >   	/* active or standby mode */
> > >   	bool active;
> > >   };
> > >  @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client
> > > *client)
> > >   {
> > >   	struct ak7375_device *ak7375_dev;
> > >   	int ret;
> > >  +	int i;
> > >
> > >   	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
> > >   				  GFP_KERNEL);
> > >   	if (!ak7375_dev)
> > >   		return -ENOMEM;
> > >
> > >  +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
> > >  +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
> > >  +
> > >  +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
> > >  +				      ak7375_dev->supplies);
> > >  +	if (ret) {
> > >  +		dev_err(&client->dev, "Failed to get regulators: %pe",
> > >  +			ERR_PTR(ret));
> > >  +		return ret;
> > >  +	}
> > >  +
> > >   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
> > >   	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > >   	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
> > >  @@ -210,6 +238,10 @@ static int __maybe_unused
> > > ak7375_vcm_suspend(struct device *dev)
> > >   	if (ret)
> > >   		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
> > >
> > >  +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES,
> > > ak7375_dev->supplies);
> > >  +	if (ret)
> > >  +		return ret;
> > >  +
> > >   	ak7375_dev->active = false;
> > >
> > >   	return 0;
> > >  @@ -230,6 +262,13 @@ static int __maybe_unused
> > > ak7375_vcm_resume(struct device *dev)
> > >   	if (ak7375_dev->active)
> > >   		return 0;
> > >
> > >  +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES,
> > > ak7375_dev->supplies);
> > >  +	if (ret)
> > >  +		return ret;
> > >  +
> > >  +	/* Wait for vcm to become ready */
> > >  +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
> > >  +
> > >   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
> > >   		AK7375_MODE_ACTIVE, 1);
> > >   	if (ret) {
> > >  --
> > >  2.37.0
> > >
>
>

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Lee Jackson]

Hello All,

This is Lee Jackson from Arducam, please check the reply following.

On Thu, 14 Jul 2022 17:58:31 +0200
Jacopo Mondi <jacopo@jmondi.org> wrote:

> Hello Yassine
> 
> On Thu, Jul 14, 2022 at 06:06:32PM +0400, Yassine Oudjana wrote:
> >
> > On Wed, Jul 13 2022 at 09:39:51 +0200, Jacopo Mondi
> > <jacopo@jmondi.org> wrote:  
> > > Hi Yassine
> > >
> > > On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:  
> > > >  From: Yassine Oudjana <y.oudjana@protonmail.com>
> > > >
> > > >  Make the driver get needed regulators on probe and
> > > > enable/disable them on runtime PM callbacks.
> > > >
> > > >  Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>  
> > >
> > > Have you seen this ?
> > > https://github.com/ArduCAM/IMX519_AK7375/blob/main/AK7375/0002-media-i2c-ak7375-driver-add-optional-regulator-suppo.patch#L172
> > >
> > > It claims
> > > +	* Initialisation delay between VDD low->high and the
> > > moment
> > > +	* when the i2c command is available.
> > > +	* From the datasheet, it should be 10ms + 2ms (max power
> > > +	* up sequence duration)
> > >
> > > 10ms seems like a long time, it would be nice to have the
> > > datasheet to cross-check.  
> >
> > It does seem quite long. I couldn't find a datasheet anywhere
> > so the value I discovered is the best I have. I've added the
> > author of that patch to CC; maybe they have some info to
> > contribute.
> >  
> 
> I have now tested these patches with an Arducam IMX519 camera.
> Using a 3msec delay I get failures in the establishing i2c
> communications (I only tested 2 times though).
> 
> With 10milliseconds (which I concur is a lot) I get stable results.
> Let's see if we can get more info from who has the manual.
> 
> Thanks
>   j
> 

We have the datasheet for the ak7371 and as far as we know they are not
much different, here is the power up sequence for the ak7371:
https://www.arducam.com/wp-content/uploads/2022/07/ak7371-power-sequence.png
(We're not very familiar with working on the linux kernel mailing list
yet, that's one reason we didn't submit ak7375patch, please let me know
if I'm doing something wrong.)

> > >
> > > Thanks
> > >    j
> > >  
> > > >  ---
> > > >  Changes since v1:
> > > >    - Reorganize variable declaration
> > > >    - Change the power-on delay range to 3000-3500 microseconds.
> > > >
> > > >   drivers/media/i2c/ak7375.c | 39
> > > > ++++++++++++++++++++++++++++++++++++++
> > > >   1 file changed, 39 insertions(+)
> > > >
> > > >  diff --git a/drivers/media/i2c/ak7375.c
> > > > b/drivers/media/i2c/ak7375.c index 40b1a4aa846c..c2b2542a0056
> > > > 100644 --- a/drivers/media/i2c/ak7375.c
> > > >  +++ b/drivers/media/i2c/ak7375.c
> > > >  @@ -6,6 +6,7 @@
> > > >   #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>
> > > >
> > > >  @@ -23,17 +24,32 @@
> > > >    */
> > > >   #define AK7375_CTRL_STEPS	64
> > > >   #define AK7375_CTRL_DELAY_US	1000
> > > >  +/*
> > > >  + * The vcm takes around 3 ms to power on and start taking
> > > >  + * I2C messages. This value was found experimentally due to
> > > >  + * lack of documentation.
> > > >  + */
> > > >  +#define AK7375_POWER_DELAY_US	3000
> > > >
> > > >   #define AK7375_REG_POSITION	0x0
> > > >   #define AK7375_REG_CONT		0x2
> > > >   #define AK7375_MODE_ACTIVE	0x0
> > > >   #define AK7375_MODE_STANDBY	0x40
> > > >
> > > >  +static const char * const ak7375_supply_names[] = {
> > > >  +	"vdd",
> > > >  +	"vio",
> > > >  +};
> > > >  +
> > > >  +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
> > > >  +
> > > >   /* ak7375 device structure */
> > > >   struct ak7375_device {
> > > >   	struct v4l2_ctrl_handler ctrls_vcm;
> > > >   	struct v4l2_subdev sd;
> > > >   	struct v4l2_ctrl *focus;
> > > >  +	struct regulator_bulk_data
> > > > supplies[AK7375_NUM_SUPPLIES]; +
> > > >   	/* active or standby mode */
> > > >   	bool active;
> > > >   };
> > > >  @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client
> > > > *client)
> > > >   {
> > > >   	struct ak7375_device *ak7375_dev;
> > > >   	int ret;
> > > >  +	int i;
> > > >
> > > >   	ak7375_dev = devm_kzalloc(&client->dev,
> > > > sizeof(*ak7375_dev), GFP_KERNEL);
> > > >   	if (!ak7375_dev)
> > > >   		return -ENOMEM;
> > > >
> > > >  +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
> > > >  +		ak7375_dev->supplies[i].supply =
> > > > ak7375_supply_names[i]; +
> > > >  +	ret = devm_regulator_bulk_get(&client->dev,
> > > > AK7375_NUM_SUPPLIES,
> > > >  +				      ak7375_dev->supplies);
> > > >  +	if (ret) {
> > > >  +		dev_err(&client->dev, "Failed to get
> > > > regulators: %pe",
> > > >  +			ERR_PTR(ret));
> > > >  +		return ret;
> > > >  +	}
> > > >  +
> > > >   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client,
> > > > &ak7375_ops); ak7375_dev->sd.flags |=
> > > > V4L2_SUBDEV_FL_HAS_DEVNODE; ak7375_dev->sd.internal_ops =
> > > > &ak7375_int_ops; @@ -210,6 +238,10 @@ static int __maybe_unused
> > > > ak7375_vcm_suspend(struct device *dev)
> > > >   	if (ret)
> > > >   		dev_err(dev, "%s I2C failure: %d\n",
> > > > __func__, ret);
> > > >
> > > >  +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES,
> > > > ak7375_dev->supplies);
> > > >  +	if (ret)
> > > >  +		return ret;
> > > >  +
> > > >   	ak7375_dev->active = false;
> > > >
> > > >   	return 0;
> > > >  @@ -230,6 +262,13 @@ static int __maybe_unused
> > > > ak7375_vcm_resume(struct device *dev)
> > > >   	if (ak7375_dev->active)
> > > >   		return 0;
> > > >
> > > >  +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES,
> > > > ak7375_dev->supplies);
> > > >  +	if (ret)
> > > >  +		return ret;
> > > >  +
> > > >  +	/* Wait for vcm to become ready */
> > > >  +	usleep_range(AK7375_POWER_DELAY_US,
> > > > AK7375_POWER_DELAY_US + 500); +
> > > >   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
> > > >   		AK7375_MODE_ACTIVE, 1);
> > > >   	if (ret) {
> > > >  --
> > > >  2.37.0
> > > >  
> >
> >  

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Christophe JAILLET]

Le 11/07/2022 à 19:31, Jacopo Mondi a écrit :
> Hi Yassine,
> 
> On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
>> From: Yassine Oudjana <y.oudjana@protonmail.com>
>>
>> Make the driver get needed regulators on probe and enable/disable
>> them on runtime PM callbacks.
>>
>> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
>> ---
>> Changes since v1:
>>    - Reorganize variable declaration
>>    - Change the power-on delay range to 3000-3500 microseconds.
>>
>>   drivers/media/i2c/ak7375.c | 39 ++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 39 insertions(+)
>>
>> diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
>> index 40b1a4aa846c..c2b2542a0056 100644
>> --- a/drivers/media/i2c/ak7375.c
>> +++ b/drivers/media/i2c/ak7375.c
>> @@ -6,6 +6,7 @@
>>   #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>
>>
>> @@ -23,17 +24,32 @@
>>    */
>>   #define AK7375_CTRL_STEPS	64
>>   #define AK7375_CTRL_DELAY_US	1000
>> +/*
>> + * The vcm takes around 3 ms to power on and start taking
>> + * I2C messages. This value was found experimentally due to
>> + * lack of documentation.
>> + */
>> +#define AK7375_POWER_DELAY_US	3000
>>
>>   #define AK7375_REG_POSITION	0x0
>>   #define AK7375_REG_CONT		0x2
>>   #define AK7375_MODE_ACTIVE	0x0
>>   #define AK7375_MODE_STANDBY	0x40
>>
>> +static const char * const ak7375_supply_names[] = {
>> +	"vdd",
>> +	"vio",
>> +};
>> +
>> +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
>> +
>>   /* ak7375 device structure */
>>   struct ak7375_device {
>>   	struct v4l2_ctrl_handler ctrls_vcm;
>>   	struct v4l2_subdev sd;
>>   	struct v4l2_ctrl *focus;
>> +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
>> +
>>   	/* active or standby mode */
>>   	bool active;
>>   };
>> @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client *client)
>>   {
>>   	struct ak7375_device *ak7375_dev;
>>   	int ret;
>> +	int i;
>>
>>   	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
>>   				  GFP_KERNEL);
>>   	if (!ak7375_dev)
>>   		return -ENOMEM;
>>
>> +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
>> +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
>> +
>> +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
>> +				      ak7375_dev->supplies);
>> +	if (ret) {
>> +		dev_err(&client->dev, "Failed to get regulators: %pe",
>> +			ERR_PTR(ret));
> 
> Why are you using %pe here ? Your return value is not a pointer
> (Also, missing \n at the end of the string)
> 
>  From Documentation/core-api/printk-formats.rst:
> 	%pe	-ENOSPC
> 
> For printing error pointers (i.e. a pointer for which IS_ERR() is true)
> as a symbolic error name. Error values for which no symbolic name is
> known are printed in decimal, while a non-ERR_PTR passed as the
> argument to %pe gets treated as ordinary %p.
> 

Nit: using:
+		return dev_err_probe(&client->dev, ret, "Failed to get regulators);

would be even simpler.

CJ


>> +		return ret;
>> +	}
>> +
>>   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
>>   	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>   	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
>> @@ -210,6 +238,10 @@ static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
>>   	if (ret)
>>   		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
>>
>> +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
>> +	if (ret)
>> +		return ret;
>> +
>>   	ak7375_dev->active = false;
>>
>>   	return 0;
>> @@ -230,6 +262,13 @@ static int __maybe_unused ak7375_vcm_resume(struct device *dev)
>>   	if (ak7375_dev->active)
>>   		return 0;
>>
>> +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Wait for vcm to become ready */
>> +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
>> +
>>   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
>>   		AK7375_MODE_ACTIVE, 1);
>>   	if (ret) {
>> --
>> 2.37.0
>>
> 

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Sakari Ailus]

Hi Yassine,

Thanks for the patch.

On Mon, Jul 11, 2022 at 06:40:39PM +0400, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
> 
> Make the driver get needed regulators on probe and enable/disable
> them on runtime PM callbacks.
> 
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> ---
> Changes since v1:
>   - Reorganize variable declaration
>   - Change the power-on delay range to 3000-3500 microseconds.
> 
>  drivers/media/i2c/ak7375.c | 39 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
> index 40b1a4aa846c..c2b2542a0056 100644
> --- a/drivers/media/i2c/ak7375.c
> +++ b/drivers/media/i2c/ak7375.c
> @@ -6,6 +6,7 @@
>  #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>
>  
> @@ -23,17 +24,32 @@
>   */
>  #define AK7375_CTRL_STEPS	64
>  #define AK7375_CTRL_DELAY_US	1000
> +/*
> + * The vcm takes around 3 ms to power on and start taking
> + * I2C messages. This value was found experimentally due to
> + * lack of documentation.
> + */
> +#define AK7375_POWER_DELAY_US	3000
>  
>  #define AK7375_REG_POSITION	0x0
>  #define AK7375_REG_CONT		0x2
>  #define AK7375_MODE_ACTIVE	0x0
>  #define AK7375_MODE_STANDBY	0x40
>  
> +static const char * const ak7375_supply_names[] = {
> +	"vdd",
> +	"vio",
> +};
> +
> +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)

Please drop this, and use ARRAY_SIZE() directly.

> +
>  /* ak7375 device structure */
>  struct ak7375_device {
>  	struct v4l2_ctrl_handler ctrls_vcm;
>  	struct v4l2_subdev sd;
>  	struct v4l2_ctrl *focus;
> +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
> +
>  	/* active or standby mode */
>  	bool active;
>  };
> @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client *client)
>  {
>  	struct ak7375_device *ak7375_dev;
>  	int ret;
> +	int i;

unsigned int, please.

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v2 1/3] media: dt-bindings: ak7375: Convert to DT schema

[Umang Jain]

Hello,

I have been testing this VCM in conjunction with Arducam's IMX519 sensor 
with libcamera and an autofocus algorithm plumbed in libcamera [1]

On 7/11/22 8:10 PM, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
>
> Convert DT bindings document for AKM AK7375 VCM to DT schema
> format and add an example.
>
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
So,

Tested-by: Umang Jain <umang.jain@ideasonboard.com>

[1] https://patchwork.libcamera.org/project/libcamera/list/?series=3174

> ---
> Changes since v1:
>    - Add vendor prefix to DT binding doc file name
>
>   .../devicetree/bindings/media/i2c/ak7375.txt  |  8 ----
>   .../media/i2c/asahi-kasei,ak7375.yaml         | 41 +++++++++++++++++++
>   MAINTAINERS                                   |  2 +-
>   3 files changed, 42 insertions(+), 9 deletions(-)
>   delete mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.txt
>   create mode 100644 Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/i2c/ak7375.txt b/Documentation/devicetree/bindings/media/i2c/ak7375.txt
> deleted file mode 100644
> index aa3e24b41241..000000000000
> --- a/Documentation/devicetree/bindings/media/i2c/ak7375.txt
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -Asahi Kasei Microdevices AK7375 voice coil lens driver
> -
> -AK7375 is a camera voice coil lens.
> -
> -Mandatory properties:
> -
> -- compatible: "asahi-kasei,ak7375"
> -- reg: I2C slave address
> diff --git a/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
> new file mode 100644
> index 000000000000..22b1251b16ee
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
> @@ -0,0 +1,41 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/i2c/asahi-kasei,ak7375.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Asahi Kasei Microdevices AK7375 voice coil lens actuator
> +
> +maintainers:
> +  - Tianshu Qiu <tian.shu.qiu@intel.com>
> +
> +description:
> +  AK7375 is a voice coil motor (VCM) camera lens actuator that
> +  is controlled over I2C.
> +
> +properties:
> +  compatible:
> +    const: asahi-kasei,ak7375
> +
> +  reg:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        ak7375: camera-lens@c {
> +            compatible = "asahi-kasei,ak7375";
> +            reg = <0x0c>;
> +        };
> +    };
> +
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a97fef8c131d..e6accf8bc12b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3063,7 +3063,7 @@ M:	Tianshu Qiu <tian.shu.qiu@intel.com>
>   L:	linux-media@vger.kernel.org
>   S:	Maintained
>   T:	git git://linuxtv.org/media_tree.git
> -F:	Documentation/devicetree/bindings/media/i2c/ak7375.txt
> +F:	Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
>   F:	drivers/media/i2c/ak7375.c
>   
>   ASAHI KASEI AK8974 DRIVER

Re: [PATCH v2 2/3] media: dt-bindings: ak7375: Add supplies

[Umang Jain]

Hi Yassine,

I have tested this VCM with IMX519 arducam sensor with a auto-focus 
algorithm plumbed with libcamera [1]

On 7/11/22 8:10 PM, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
>
> Add supply properties to describe regulators needed to power
> the AK7375 VCM.
>
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

So,

Tested-by: Umang Jain <umang.jain@ideasonboard.com>

[1] https://patchwork.libcamera.org/project/libcamera/list/?series=3174
> ---
>   .../bindings/media/i2c/asahi-kasei,ak7375.yaml        | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
> index 22b1251b16ee..22a810fc7222 100644
> --- a/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
> +++ b/Documentation/devicetree/bindings/media/i2c/asahi-kasei,ak7375.yaml
> @@ -20,9 +20,17 @@ properties:
>     reg:
>       maxItems: 1
>   
> +  vdd-supply:
> +    description: VDD supply
> +
> +  vio-supply:
> +    description: I/O pull-up supply
> +
>   required:
>     - compatible
>     - reg
> +  - vdd-supply
> +  - vio-supply
>   
>   additionalProperties: false
>   
> @@ -35,6 +43,9 @@ examples:
>           ak7375: camera-lens@c {
>               compatible = "asahi-kasei,ak7375";
>               reg = <0x0c>;
> +
> +            vdd-supply = <&vreg_l23a_2p8>;
> +            vio-supply = <&vreg_lvs1a_1p8>;
>           };
>       };
>   

Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management

[Umang Jain]

Hi Yassine,

I have tested this VCM with autofocus algorithm plumbed in libcamera [1]

On 7/11/22 8:10 PM, Yassine Oudjana wrote:
> From: Yassine Oudjana <y.oudjana@protonmail.com>
>
> Make the driver get needed regulators on probe and enable/disable
> them on runtime PM callbacks.
>
> Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>

Tested-by: Umang Jain <umang.jain@ideasonboard.com>

[1] https://patchwork.libcamera.org/project/libcamera/list/?series=3174
> ---
> Changes since v1:
>    - Reorganize variable declaration
>    - Change the power-on delay range to 3000-3500 microseconds.
>
>   drivers/media/i2c/ak7375.c | 39 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 39 insertions(+)
>
> diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c
> index 40b1a4aa846c..c2b2542a0056 100644
> --- a/drivers/media/i2c/ak7375.c
> +++ b/drivers/media/i2c/ak7375.c
> @@ -6,6 +6,7 @@
>   #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>
>   
> @@ -23,17 +24,32 @@
>    */
>   #define AK7375_CTRL_STEPS	64
>   #define AK7375_CTRL_DELAY_US	1000
> +/*
> + * The vcm takes around 3 ms to power on and start taking
> + * I2C messages. This value was found experimentally due to
> + * lack of documentation.
> + */
> +#define AK7375_POWER_DELAY_US	3000
>   
>   #define AK7375_REG_POSITION	0x0
>   #define AK7375_REG_CONT		0x2
>   #define AK7375_MODE_ACTIVE	0x0
>   #define AK7375_MODE_STANDBY	0x40
>   
> +static const char * const ak7375_supply_names[] = {
> +	"vdd",
> +	"vio",
> +};
> +
> +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names)
> +
>   /* ak7375 device structure */
>   struct ak7375_device {
>   	struct v4l2_ctrl_handler ctrls_vcm;
>   	struct v4l2_subdev sd;
>   	struct v4l2_ctrl *focus;
> +	struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES];
> +
>   	/* active or standby mode */
>   	bool active;
>   };
> @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client *client)
>   {
>   	struct ak7375_device *ak7375_dev;
>   	int ret;
> +	int i;
>   
>   	ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev),
>   				  GFP_KERNEL);
>   	if (!ak7375_dev)
>   		return -ENOMEM;
>   
> +	for (i = 0; i < AK7375_NUM_SUPPLIES; i++)
> +		ak7375_dev->supplies[i].supply = ak7375_supply_names[i];
> +
> +	ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES,
> +				      ak7375_dev->supplies);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to get regulators: %pe",
> +			ERR_PTR(ret));
> +		return ret;
> +	}
> +
>   	v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops);
>   	ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>   	ak7375_dev->sd.internal_ops = &ak7375_int_ops;
> @@ -210,6 +238,10 @@ static int __maybe_unused ak7375_vcm_suspend(struct device *dev)
>   	if (ret)
>   		dev_err(dev, "%s I2C failure: %d\n", __func__, ret);
>   
> +	ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
> +	if (ret)
> +		return ret;
> +
>   	ak7375_dev->active = false;
>   
>   	return 0;
> @@ -230,6 +262,13 @@ static int __maybe_unused ak7375_vcm_resume(struct device *dev)
>   	if (ak7375_dev->active)
>   		return 0;
>   
> +	ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, ak7375_dev->supplies);
> +	if (ret)
> +		return ret;
> +
> +	/* Wait for vcm to become ready */
> +	usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 500);
> +
>   	ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT,
>   		AK7375_MODE_ACTIVE, 1);
>   	if (ret) {
>