[PATCH v2 0/6] OV9281 support

[PATCH v2 0/6] OV9281 support

[Alexander Stein]

Hi,

this is the 2nd series adding support for OV9281 which is quite similar to OV9282.
This includes:
* a small cleanup (Patch 1)
* adding a new compatible (Patch 2 & 3)
* adding support for regulators (Patch 4 & 5)
* Fix reading ID register on VC MIPI OV9281 (Patch 6)

Thanks for anyone doing review and giving a feedback.
Here are the changes in v2:
* Added Krzysztof's a-b for Patch 2 & 4
* Added Daniele's a-b for Patch 1 & 3
* Removed additional error message in ov9282_power_off
* Renamed function from ov9282_configure_regulators to ov9282_get_regulators
* Cleaned-up reading ID registers

The regulator support is based on the driver from Raspberry Pi downstream kernel
[1], the ID register read fix as well. Please refer to [2] why this fix is
required. I can confirm this is necessary by checking with a Logic analyzer on
the i2c bus.

Best regards,
Alexander

[1] https://github.com/raspberrypi/linux/blob/rpi-5.15.y/drivers/media/i2c/ov9281.c
[2] https://github.com/raspberrypi/linux/commit/58deee7c917e1c3c5e37987c3a89ad19d791f58a


Alexander Stein (6):
  media: i2c: ov9282: remove unused and unset i2c_client member
  media: dt-bindings: media: Add compatible for ov9281
  media: i2c: ov9282: Add ov9281 compatible
  media: dt-bindings: media: ov9282: Add power supply properties
  media: i2c: ov9282: Add regulator support
  media: i2c: ov9282: Fix device detection

 .../bindings/media/i2c/ovti,ov9282.yaml       | 14 ++++-
 drivers/media/i2c/ov9282.c                    | 56 ++++++++++++++++++-
 2 files changed, 67 insertions(+), 3 deletions(-)

-- 
2.25.1

[PATCH v2 1/6] media: i2c: ov9282: remove unused and unset i2c_client member

[Alexander Stein]

This is not need anyway as the i2c_client is stored in v4l2_subdev.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Acked-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
---
 drivers/media/i2c/ov9282.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
index 2e0b315801e5..3269c1983bd5 100644
--- a/drivers/media/i2c/ov9282.c
+++ b/drivers/media/i2c/ov9282.c
@@ -123,7 +123,6 @@ struct ov9282_mode {
  */
 struct ov9282 {
 	struct device *dev;
-	struct i2c_client *client;
 	struct v4l2_subdev sd;
 	struct media_pad pad;
 	struct gpio_desc *reset_gpio;
-- 
2.25.1

[PATCH v2 2/6] media: dt-bindings: media: Add compatible for ov9281

[Alexander Stein]

This is a slightly different hardware with identical software interface.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml b/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml
index bf115ab9d926..285f8c85f253 100644
--- a/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml
+++ b/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml
@@ -16,10 +16,13 @@ description:
   sensor with an active array size of 1296H x 816V. It is programmable through
   I2C interface. The I2C client address is fixed to 0x60/0x70 as per sensor data
   sheet. Image data is sent through MIPI CSI-2.
+  OV9281 has a different lens chief ray angle.
 
 properties:
   compatible:
-    const: ovti,ov9282
+    enum:
+      - ovti,ov9281
+      - ovti,ov9282
   reg:
     description: I2C address
     maxItems: 1
-- 
2.25.1

[PATCH v2 3/6] media: i2c: ov9282: Add ov9281 compatible

[Alexander Stein]

According to product brief they are identical from software point of view.
Differences are a different chief ray angle (CRA) and the package.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Acked-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
---
 drivers/media/i2c/ov9282.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
index 3269c1983bd5..04fda8222e07 100644
--- a/drivers/media/i2c/ov9282.c
+++ b/drivers/media/i2c/ov9282.c
@@ -1114,6 +1114,7 @@ static const struct dev_pm_ops ov9282_pm_ops = {
 };
 
 static const struct of_device_id ov9282_of_match[] = {
+	{ .compatible = "ovti,ov9281" },
 	{ .compatible = "ovti,ov9282" },
 	{ }
 };
-- 
2.25.1

Re: [PATCH v2 3/6] media: i2c: ov9282: Add ov9281 compatible

[Sakari Ailus]

Hi Alexander,

On Fri, Jul 15, 2022 at 09:48:55AM +0200, Alexander Stein wrote:
> According to product brief they are identical from software point of view.
> Differences are a different chief ray angle (CRA) and the package.
> 
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> Acked-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
> ---
>  drivers/media/i2c/ov9282.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> index 3269c1983bd5..04fda8222e07 100644
> --- a/drivers/media/i2c/ov9282.c
> +++ b/drivers/media/i2c/ov9282.c
> @@ -1114,6 +1114,7 @@ static const struct dev_pm_ops ov9282_pm_ops = {
>  };
>  
>  static const struct of_device_id ov9282_of_match[] = {
> +	{ .compatible = "ovti,ov9281" },

This should also be reflected in the entity name --- the user space
deserves to know it's a different device.

>  	{ .compatible = "ovti,ov9282" },
>  	{ }
>  };

-- 
Sakari Ailus

Re: [PATCH v2 3/6] media: i2c: ov9282: Add ov9281 compatible

[Alexander Stein]

Am Sonntag, 17. Juli 2022, 16:23:17 CEST schrieb Sakari Ailus:
> Hi Alexander,
> 
> On Fri, Jul 15, 2022 at 09:48:55AM +0200, Alexander Stein wrote:
> > According to product brief they are identical from software point of view.
> > Differences are a different chief ray angle (CRA) and the package.
> > 
> > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > Acked-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
> > ---
> > 
> >  drivers/media/i2c/ov9282.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> > index 3269c1983bd5..04fda8222e07 100644
> > --- a/drivers/media/i2c/ov9282.c
> > +++ b/drivers/media/i2c/ov9282.c
> > @@ -1114,6 +1114,7 @@ static const struct dev_pm_ops ov9282_pm_ops = {
> > 
> >  };
> >  
> >  static const struct of_device_id ov9282_of_match[] = {
> > 
> > +	{ .compatible = "ovti,ov9281" },
> 
> This should also be reflected in the entity name --- the user space
> deserves to know it's a different device.

Not so sure what to do here. v4l2_i2c_subdev_set_name is called from 
v4l2_i2c_subdev_init() with devname=NULL. This should set the correct name. 
According to it's documentation with the I²C device name, but apparently 
v4l2_i2c_subdev_set_name uses the drivers name.
This seems a bug to me, but is outside of this driver.

Best regards,
Alexander

> >  	{ .compatible = "ovti,ov9282" },
> >  	{ }
> >  
> >  };

[PATCH v2 4/6] media: dt-bindings: media: ov9282: Add power supply properties

[Alexander Stein]

Add regulators for each power domain.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../devicetree/bindings/media/i2c/ovti,ov9282.yaml       | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml b/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml
index 285f8c85f253..9abfaabd373a 100644
--- a/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml
+++ b/Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml
@@ -39,6 +39,15 @@ properties:
     description: Reference to the GPIO connected to the XCLR pin, if any.
     maxItems: 1
 
+  avdd-supply:
+    description: Analog power supply
+
+  dovdd-supply:
+    description: Digital I/O power supply
+
+  dvdd-supply:
+    description: Digital core supply
+
   port:
     additionalProperties: false
     $ref: /schemas/graph.yaml#/$defs/port-base
-- 
2.25.1

[PATCH v2 5/6] media: i2c: ov9282: Add regulator support

[Alexander Stein]

Need in case the sensors is supplied by a switchable regulator.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
Changes in v2:
* Remove error message for failed regulator_bulk_disable()
* Rename ov9282_configure_regulators to ov9282_get_regulators

 drivers/media/i2c/ov9282.c | 39 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
index 04fda8222e07..263cdffc558f 100644
--- a/drivers/media/i2c/ov9282.c
+++ b/drivers/media/i2c/ov9282.c
@@ -11,6 +11,7 @@
 #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-fwnode.h>
@@ -55,6 +56,14 @@
 #define OV9282_REG_MIN		0x00
 #define OV9282_REG_MAX		0xfffff
 
+static const char * const ov9282_supply_names[] = {
+	"avdd",		/* Analog power */
+	"dovdd",	/* Digital I/O power */
+	"dvdd",		/* Digital core power */
+};
+
+#define OV9282_NUM_SUPPLIES ARRAY_SIZE(ov9282_supply_names)
+
 /**
  * struct ov9282_reg - ov9282 sensor register
  * @address: Register address
@@ -127,6 +136,7 @@ struct ov9282 {
 	struct media_pad pad;
 	struct gpio_desc *reset_gpio;
 	struct clk *inclk;
+	struct regulator_bulk_data supplies[OV9282_NUM_SUPPLIES];
 	struct v4l2_ctrl_handler ctrl_handler;
 	struct v4l2_ctrl *link_freq_ctrl;
 	struct v4l2_ctrl *pclk_ctrl;
@@ -883,10 +893,18 @@ static int ov9282_power_on(struct device *dev)
 		goto error_reset;
 	}
 
+	ret = regulator_bulk_enable(ARRAY_SIZE(ov9282->supplies), ov9282->supplies);
+	if (ret) {
+		dev_err(dev, "Failed to enable regulators\n");
+		goto disable_clk;
+	}
+
 	usleep_range(400, 600);
 
 	return 0;
 
+disable_clk:
+	clk_disable_unprepare(ov9282->inclk);
 error_reset:
 	gpiod_set_value_cansleep(ov9282->reset_gpio, 0);
 
@@ -903,6 +921,9 @@ static int ov9282_power_off(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct ov9282 *ov9282 = to_ov9282(sd);
+	int ret;
+
+	regulator_bulk_disable(ARRAY_SIZE(ov9282->supplies), ov9282->supplies);
 
 	gpiod_set_value_cansleep(ov9282->reset_gpio, 0);
 
@@ -996,6 +1017,18 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
 	return 0;
 }
 
+static int ov9282_get_regulators(struct ov9282 *ov9282)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(ov9282->supplies); i++)
+		ov9282->supplies[i].supply = ov9282_supply_names[i];
+
+	return devm_regulator_bulk_get(ov9282->dev,
+				       ARRAY_SIZE(ov9282->supplies),
+				       ov9282->supplies);
+}
+
 /**
  * ov9282_probe() - I2C client device binding
  * @client: pointer to i2c client device
@@ -1022,6 +1055,12 @@ static int ov9282_probe(struct i2c_client *client)
 		return ret;
 	}
 
+	ret = ov9282_get_regulators(ov9282);
+	if (ret) {
+		dev_err(&client->dev, "Failed to get power regulators\n");
+		return ret;
+	}
+
 	mutex_init(&ov9282->mutex);
 
 	ret = ov9282_power_on(ov9282->dev);
-- 
2.25.1

Re: [PATCH v2 5/6] media: i2c: ov9282: Add regulator support

[Sakari Ailus]

Hi Alexander,

Thanks for the set.

On Fri, Jul 15, 2022 at 09:48:57AM +0200, Alexander Stein wrote:
> Need in case the sensors is supplied by a switchable regulator.
> 
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> ---
> Changes in v2:
> * Remove error message for failed regulator_bulk_disable()
> * Rename ov9282_configure_regulators to ov9282_get_regulators
> 
>  drivers/media/i2c/ov9282.c | 39 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> index 04fda8222e07..263cdffc558f 100644
> --- a/drivers/media/i2c/ov9282.c
> +++ b/drivers/media/i2c/ov9282.c
> @@ -11,6 +11,7 @@
>  #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-fwnode.h>
> @@ -55,6 +56,14 @@
>  #define OV9282_REG_MIN		0x00
>  #define OV9282_REG_MAX		0xfffff
>  
> +static const char * const ov9282_supply_names[] = {
> +	"avdd",		/* Analog power */
> +	"dovdd",	/* Digital I/O power */
> +	"dvdd",		/* Digital core power */
> +};
> +
> +#define OV9282_NUM_SUPPLIES ARRAY_SIZE(ov9282_supply_names)
> +
>  /**
>   * struct ov9282_reg - ov9282 sensor register
>   * @address: Register address
> @@ -127,6 +136,7 @@ struct ov9282 {
>  	struct media_pad pad;
>  	struct gpio_desc *reset_gpio;
>  	struct clk *inclk;
> +	struct regulator_bulk_data supplies[OV9282_NUM_SUPPLIES];
>  	struct v4l2_ctrl_handler ctrl_handler;
>  	struct v4l2_ctrl *link_freq_ctrl;
>  	struct v4l2_ctrl *pclk_ctrl;
> @@ -883,10 +893,18 @@ static int ov9282_power_on(struct device *dev)
>  		goto error_reset;
>  	}
>  
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ov9282->supplies), ov9282->supplies);

Please run the set through:

	./scripts/checkpatch.pl --strict --max-line-length=80

> +	if (ret) {
> +		dev_err(dev, "Failed to enable regulators\n");
> +		goto disable_clk;
> +	}
> +
>  	usleep_range(400, 600);
>  
>  	return 0;
>  
> +disable_clk:
> +	clk_disable_unprepare(ov9282->inclk);
>  error_reset:
>  	gpiod_set_value_cansleep(ov9282->reset_gpio, 0);
>  
> @@ -903,6 +921,9 @@ static int ov9282_power_off(struct device *dev)
>  {
>  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
>  	struct ov9282 *ov9282 = to_ov9282(sd);
> +	int ret;

ret seems to be unused.

> +
> +	regulator_bulk_disable(ARRAY_SIZE(ov9282->supplies), ov9282->supplies);
>  
>  	gpiod_set_value_cansleep(ov9282->reset_gpio, 0);
>  
> @@ -996,6 +1017,18 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
>  	return 0;
>  }
>  
> +static int ov9282_get_regulators(struct ov9282 *ov9282)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(ov9282->supplies); i++)
> +		ov9282->supplies[i].supply = ov9282_supply_names[i];
> +
> +	return devm_regulator_bulk_get(ov9282->dev,
> +				       ARRAY_SIZE(ov9282->supplies),
> +				       ov9282->supplies);
> +}
> +
>  /**
>   * ov9282_probe() - I2C client device binding
>   * @client: pointer to i2c client device
> @@ -1022,6 +1055,12 @@ static int ov9282_probe(struct i2c_client *client)
>  		return ret;
>  	}
>  
> +	ret = ov9282_get_regulators(ov9282);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to get power regulators\n");
> +		return ret;
> +	}
> +
>  	mutex_init(&ov9282->mutex);
>  
>  	ret = ov9282_power_on(ov9282->dev);

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v2 5/6] media: i2c: ov9282: Add regulator support

[Alexander Stein]

Hi Sakari,

Am Sonntag, 17. Juli 2022, 16:17:09 CEST schrieb Sakari Ailus:
> Hi Alexander,
> 
> Thanks for the set.
> 
> On Fri, Jul 15, 2022 at 09:48:57AM +0200, Alexander Stein wrote:
> > Need in case the sensors is supplied by a switchable regulator.
> > 
> > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > ---
> > Changes in v2:
> > * Remove error message for failed regulator_bulk_disable()
> > * Rename ov9282_configure_regulators to ov9282_get_regulators
> > 
> >  drivers/media/i2c/ov9282.c | 39 ++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 39 insertions(+)
> > 
> > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> > index 04fda8222e07..263cdffc558f 100644
> > --- a/drivers/media/i2c/ov9282.c
> > +++ b/drivers/media/i2c/ov9282.c
> > @@ -11,6 +11,7 @@
> > 
> >  #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-fwnode.h>
> > 
> > @@ -55,6 +56,14 @@
> > 
> >  #define OV9282_REG_MIN		0x00
> >  #define OV9282_REG_MAX		0xfffff
> > 
> > +static const char * const ov9282_supply_names[] = {
> > +	"avdd",		/* Analog power */
> > +	"dovdd",	/* Digital I/O power */
> > +	"dvdd",		/* Digital core power */
> > +};
> > +
> > +#define OV9282_NUM_SUPPLIES ARRAY_SIZE(ov9282_supply_names)
> > +
> > 
> >  /**
> >  
> >   * struct ov9282_reg - ov9282 sensor register
> >   * @address: Register address
> > 
> > @@ -127,6 +136,7 @@ struct ov9282 {
> > 
> >  	struct media_pad pad;
> >  	struct gpio_desc *reset_gpio;
> >  	struct clk *inclk;
> > 
> > +	struct regulator_bulk_data supplies[OV9282_NUM_SUPPLIES];
> > 
> >  	struct v4l2_ctrl_handler ctrl_handler;
> >  	struct v4l2_ctrl *link_freq_ctrl;
> >  	struct v4l2_ctrl *pclk_ctrl;
> > 
> > @@ -883,10 +893,18 @@ static int ov9282_power_on(struct device *dev)
> > 
> >  		goto error_reset;
> >  	
> >  	}
> > 
> > +	ret = regulator_bulk_enable(ARRAY_SIZE(ov9282->supplies),
> > ov9282->supplies);
> Please run the set through:
> 
> 	./scripts/checkpatch.pl --strict --max-line-length=80

Thanks, will be fixed.

> > +	if (ret) {
> > +		dev_err(dev, "Failed to enable regulators\n");
> > +		goto disable_clk;
> > +	}
> > +
> > 
> >  	usleep_range(400, 600);
> >  	
> >  	return 0;
> > 
> > +disable_clk:
> > +	clk_disable_unprepare(ov9282->inclk);
> > 
> >  error_reset:
> >  	gpiod_set_value_cansleep(ov9282->reset_gpio, 0);
> > 
> > @@ -903,6 +921,9 @@ static int ov9282_power_off(struct device *dev)
> > 
> >  {
> >  
> >  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >  	struct ov9282 *ov9282 = to_ov9282(sd);
> > 
> > +	int ret;
> 
> ret seems to be unused.

You are right, leftover from last cleanup. Will be removed.

Thanks and best regards,
Alexander

> > +
> > +	regulator_bulk_disable(ARRAY_SIZE(ov9282->supplies), ov9282-
>supplies);
> > 
> >  	gpiod_set_value_cansleep(ov9282->reset_gpio, 0);
> > 
> > @@ -996,6 +1017,18 @@ static int ov9282_init_controls(struct ov9282
> > *ov9282)> 
> >  	return 0;
> >  
> >  }
> > 
> > +static int ov9282_get_regulators(struct ov9282 *ov9282)
> > +{
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(ov9282->supplies); i++)
> > +		ov9282->supplies[i].supply = ov9282_supply_names[i];
> > +
> > +	return devm_regulator_bulk_get(ov9282->dev,
> > +				       ARRAY_SIZE(ov9282-
>supplies),
> > +				       ov9282->supplies);
> > +}
> > +
> > 
> >  /**
> >  
> >   * ov9282_probe() - I2C client device binding
> >   * @client: pointer to i2c client device
> > 
> > @@ -1022,6 +1055,12 @@ static int ov9282_probe(struct i2c_client *client)
> > 
> >  		return ret;
> >  	
> >  	}
> > 
> > +	ret = ov9282_get_regulators(ov9282);
> > +	if (ret) {
> > +		dev_err(&client->dev, "Failed to get power 
regulators\n");
> > +		return ret;
> > +	}
> > +
> > 
> >  	mutex_init(&ov9282->mutex);
> >  	
> >  	ret = ov9282_power_on(ov9282->dev);

[PATCH v2 6/6] media: i2c: ov9282: Fix device detection

[Alexander Stein]

Apparently the Vision Components model (VC MIPI OV9281) does not support
address auto-increment, so probe fails with:
ov9282 2-0060: chip id mismatch: 9281!=92ff
Instead do two 1 byte reads and combine the result.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
Changes in v2:
* Fix commit message
* Add comment about prevented auto-increment
* Return early if reading ID register failed
* Reorder ID registers, smaller register number first

 drivers/media/i2c/ov9282.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
index 263cdffc558f..532791304c3d 100644
--- a/drivers/media/i2c/ov9282.c
+++ b/drivers/media/i2c/ov9282.c
@@ -761,11 +761,24 @@ static int ov9282_set_stream(struct v4l2_subdev *sd, int enable)
 static int ov9282_detect(struct ov9282 *ov9282)
 {
 	int ret;
+	u32 id[2];
 	u32 val;
 
-	ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 2, &val);
+	/*
+	 * Some vendors prevent auto-increment, so each register has to
+	 * be read separately
+	 */
+	ret = ov9282_read_reg(ov9282, OV9282_REG_ID,
+			      1, &id[0]);
 	if (ret)
 		return ret;
+	ret = ov9282_read_reg(ov9282, OV9282_REG_ID + 1,
+			      1, &id[1]);
+	if (ret)
+		return ret;
+
+	val = id[1];
+	val |= (id[0] << 8);
 
 	if (val != OV9282_ID) {
 		dev_err(ov9282->dev, "chip id mismatch: %x!=%x",
-- 
2.25.1

Re: [PATCH v2 6/6] media: i2c: ov9282: Fix device detection

[Sakari Ailus]

Hi Alexander,

On Fri, Jul 15, 2022 at 09:48:58AM +0200, Alexander Stein wrote:
> Apparently the Vision Components model (VC MIPI OV9281) does not support
> address auto-increment, so probe fails with:
> ov9282 2-0060: chip id mismatch: 9281!=92ff
> Instead do two 1 byte reads and combine the result.
> 
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> ---
> Changes in v2:
> * Fix commit message
> * Add comment about prevented auto-increment
> * Return early if reading ID register failed
> * Reorder ID registers, smaller register number first
> 
>  drivers/media/i2c/ov9282.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> index 263cdffc558f..532791304c3d 100644
> --- a/drivers/media/i2c/ov9282.c
> +++ b/drivers/media/i2c/ov9282.c
> @@ -761,11 +761,24 @@ static int ov9282_set_stream(struct v4l2_subdev *sd, int enable)
>  static int ov9282_detect(struct ov9282 *ov9282)
>  {
>  	int ret;
> +	u32 id[2];
>  	u32 val;
>  
> -	ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 2, &val);
> +	/*
> +	 * Some vendors prevent auto-increment, so each register has to
> +	 * be read separately
> +	 */

I suppose it still works for writes I guess? Would be nice to have this in
the comment.

> +	ret = ov9282_read_reg(ov9282, OV9282_REG_ID,
> +			      1, &id[0]);

Fits on one line. Same below.

>  	if (ret)
>  		return ret;
> +	ret = ov9282_read_reg(ov9282, OV9282_REG_ID + 1,
> +			      1, &id[1]);
> +	if (ret)
> +		return ret;
> +
> +	val = id[1];
> +	val |= (id[0] << 8);
>  
>  	if (val != OV9282_ID) {
>  		dev_err(ov9282->dev, "chip id mismatch: %x!=%x",

-- 
Sakari Ailus

Re: Re: [PATCH v2 6/6] media: i2c: ov9282: Fix device detection

[Alexander Stein]

Hello Sakari,

thanks for the feedback.

Am Sonntag, 17. Juli 2022, 16:22:01 CEST schrieb Sakari Ailus:
> Hi Alexander,
> 
> On Fri, Jul 15, 2022 at 09:48:58AM +0200, Alexander Stein wrote:
> > Apparently the Vision Components model (VC MIPI OV9281) does not support
> > address auto-increment, so probe fails with:
> > ov9282 2-0060: chip id mismatch: 9281!=92ff
> > Instead do two 1 byte reads and combine the result.
> > 
> > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > ---
> > Changes in v2:
> > * Fix commit message
> > * Add comment about prevented auto-increment
> > * Return early if reading ID register failed
> > * Reorder ID registers, smaller register number first
> > 
> >  drivers/media/i2c/ov9282.c | 15 ++++++++++++++-
> >  1 file changed, 14 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> > index 263cdffc558f..532791304c3d 100644
> > --- a/drivers/media/i2c/ov9282.c
> > +++ b/drivers/media/i2c/ov9282.c
> > @@ -761,11 +761,24 @@ static int ov9282_set_stream(struct v4l2_subdev *sd,
> > int enable)> 
> >  static int ov9282_detect(struct ov9282 *ov9282)
> >  {
> >  
> >  	int ret;
> > 
> > +	u32 id[2];
> > 
> >  	u32 val;
> > 
> > -	ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 2, &val);
> > +	/*
> > +	 * Some vendors prevent auto-increment, so each register has to
> > +	 * be read separately
> > +	 */
> 
> I suppose it still works for writes I guess? Would be nice to have this in
> the comment.

Yes, I didn't notice any problems regarding writes. Will address this in the 
comment.

> > +	ret = ov9282_read_reg(ov9282, OV9282_REG_ID,
> > +			      1, &id[0]);
> 
> Fits on one line. Same below.

Sure, will be changed.

Thanks and best regards,
Alexander

> >  	if (ret)
> >  	
> >  		return ret;
> > 
> > +	ret = ov9282_read_reg(ov9282, OV9282_REG_ID + 1,
> > +			      1, &id[1]);
> > +	if (ret)
> > +		return ret;
> > +
> > +	val = id[1];
> > +	val |= (id[0] << 8);
> > 
> >  	if (val != OV9282_ID) {
> >  	
> >  		dev_err(ov9282->dev, "chip id mismatch: %x!=%x",

Re: [PATCH v2 6/6] media: i2c: ov9282: Fix device detection

[Alexander Stein]

Hi,

Am Sonntag, 17. Juli 2022, 16:22:01 CEST schrieb Sakari Ailus:
> Hi Alexander,
> 
> On Fri, Jul 15, 2022 at 09:48:58AM +0200, Alexander Stein wrote:
> > Apparently the Vision Components model (VC MIPI OV9281) does not support
> > address auto-increment, so probe fails with:
> > ov9282 2-0060: chip id mismatch: 9281!=92ff
> > Instead do two 1 byte reads and combine the result.
> > 
> > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > ---
> > Changes in v2:
> > * Fix commit message
> > * Add comment about prevented auto-increment
> > * Return early if reading ID register failed
> > * Reorder ID registers, smaller register number first
> > 
> >  drivers/media/i2c/ov9282.c | 15 ++++++++++++++-
> >  1 file changed, 14 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> > index 263cdffc558f..532791304c3d 100644
> > --- a/drivers/media/i2c/ov9282.c
> > +++ b/drivers/media/i2c/ov9282.c
> > @@ -761,11 +761,24 @@ static int ov9282_set_stream(struct v4l2_subdev *sd,
> > int enable)> 
> >  static int ov9282_detect(struct ov9282 *ov9282)
> >  {
> >  
> >  	int ret;
> > 
> > +	u32 id[2];
> > 
> >  	u32 val;
> > 
> > -	ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 2, &val);
> > +	/*
> > +	 * Some vendors prevent auto-increment, so each register has to
> > +	 * be read separately
> > +	 */
> 
> I suppose it still works for writes I guess? Would be nice to have this in
> the comment.
> 
> > +	ret = ov9282_read_reg(ov9282, OV9282_REG_ID,
> > +			      1, &id[0]);
> 
> Fits on one line. Same below.
> 
> >  	if (ret)
> >  	
> >  		return ret;
> > 
> > +	ret = ov9282_read_reg(ov9282, OV9282_REG_ID + 1,
> > +			      1, &id[1]);
> > +	if (ret)
> > +		return ret;
> > +
> > +	val = id[1];
> > +	val |= (id[0] << 8);
> > 
> >  	if (val != OV9282_ID) {
> >  	
> >  		dev_err(ov9282->dev, "chip id mismatch: %x!=%x",

imx290 is affected by the same problem. This can be handles by using regmap's 
config option use_single_read=true.

Will convert to regmap to address this.

Best regards,
Alexander