Add support for Omnivision OV5647

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +7 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +18 -0

+
+Example:
+
+	i2c@2000 {
+		...
+		ov: camera@36 {
+			compatible = "ovti,ov5647";
+			reg = <0x36>;
+			clocks = <&camera_clk>;
+			clock-names = "xclk";
+			clock-frequency = <25000000>;
+			port {
+				camera_1: endpoint {
+					remote-endpoint = <&csi1_ep1>;
+				};
+			};
+		};
+	};

Hi Ramiro,

Quoted 30 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +15 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.
+- clock-names		: Should be "xclk".
+- clock-frequency	: Frequency of the xclk clock.
+
+The common video interfaces bindings (see video-interfaces.txt) should be

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 17

Quoted 2 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +2 -0

+used to specify link to the image data receiver. The OV5647 device
+node should contain one 'port' child node with an 'endpoint' subnode.

The remote-endpoint property in endpoint nodes should be mandatory, shouldn't it? Otherwise the sensor isn't connected to anything and hardly useful as such. The list of optional endpoint properties is a long one and it should be documented here which ones are recognised, either as optional or mandatory.

Quoted 18 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +18 -0

+
+Example:
+
+	i2c@2000 {
+		...
+		ov: camera@36 {
+			compatible = "ovti,ov5647";
+			reg = <0x36>;
+			clocks = <&camera_clk>;
+			clock-names = "xclk";
+			clock-frequency = <25000000>;
+			port {
+				camera_1: endpoint {
+					remote-endpoint = <&csi1_ep1>;
+				};
+			};
+		};
+	};

Hi Sakari,

Thank you for your feedback.

Quoted 33 lines · Sakari Ailus

Hi Ramiro,

Quoted 30 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +15 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.
+- clock-names		: Should be "xclk".
+- clock-frequency	: Frequency of the xclk clock.
+
+The common video interfaces bindings (see video-interfaces.txt) should be

Quoted 9 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 17

Quoted 2 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +2 -0

+used to specify link to the image data receiver. The OV5647 device
+node should contain one 'port' child node with an 'endpoint' subnode.

The remote-endpoint property in endpoint nodes should be mandatory, shouldn't it? Otherwise the sensor isn't connected to anything and hardly useful as such. The list of optional endpoint properties is a long one and it should be documented here which ones are recognised, either as optional or mandatory.

I guess you're right, it should be mandatory, although at the moment I'm not checking for it's presence in the driver so I'll add it to the driver.

At the moment that's the only property I think it should be mandatory, and I don't believe I need any optional one.

Do you have a suggestion for any new property I should use?

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

+
+The common video interfaces bindings (see video-interfaces.txt) should be
+used to specify link to the image data receiver. The OV5647 device
+node should contain one 'port' child node with an 'endpoint' subnode.
+

Hi Ramiro,

Quoted 20 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 6 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +6 -0

+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

You can remove this property, because there is only one source clock.

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 10 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+
+The common video interfaces bindings (see video-interfaces.txt) should be
+used to specify link to the image data receiver. The OV5647 device
+node should contain one 'port' child node with an 'endpoint' subnode.
+
+Example:
+
+	i2c@2000 {
+		...
+		ov: camera@36 {

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 28

Quoted 5 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

+			compatible = "ovti,ov5647";
+			reg = <0x36>;
+			clocks = <&camera_clk>;
+			clock-names = "xclk";
+			clock-frequency = <25000000>;

When you remove two unused properties, please don't forget to update the example.

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 35

Quoted 8 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +7 -0

+			port {
+				camera_1: endpoint {
+					remote-endpoint = <&csi1_ep1>;
+				};
+			};
+		};
+	};

--
With best wishes,
Vladimir

Hi Vladimir,

Thank you for your feedback

Quoted 23 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 20 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.

Quoted 9 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 6 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +6 -0

+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

It's an external oscillator.

Quoted 5 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 2 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

Quoted 10 lines

Quoted 10 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+
+The common video interfaces bindings (see video-interfaces.txt) should be
+used to specify link to the image data receiver. The OV5647 device
+node should contain one 'port' child node with an 'endpoint' subnode.
+
+Example:
+
+	i2c@2000 {
+		...
+		ov: camera@36 {

Quoted 9 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 28

Quoted 5 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

+			compatible = "ovti,ov5647";
+			reg = <0x36>;
+			clocks = <&camera_clk>;
+			clock-names = "xclk";
+			clock-frequency = <25000000>;

When you remove two unused properties, please don't forget to update the example.

Ok.

Quoted 9 lines

Quoted 8 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +7 -0

+			port {
+				camera_1: endpoint {
+					remote-endpoint = <&csi1_ep1>;
+				};
+			};
+		};
+	};

Hi Ramiro,

Quoted 38 lines · Ramiro Oliveira

Hi Vladimir,

Thank you for your feedback

Quoted 32 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 16 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 10 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Quoted 1 line

It's an external oscillator.

hmm, I suppose a clock of any type could serve as a clock for the sensor. It can be an external oscillator on a particular board, or it can be something else on another board.

Can you please describe what for does ov5647 sensor need this clock, what is its function?

Quoted 14 lines

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Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 3 lines

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

I doubt it, there should be no connection between a custom "clock-frequency" device tree property in a clock consumer device node and clk_get_rate() function from the CCF, which takes a clock provider as its argument.

Quoted 21 lines

Quoted 11 lines

Quoted 11 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+
+The common video interfaces bindings (see video-interfaces.txt) should be
+used to specify link to the image data receiver. The OV5647 device
+node should contain one 'port' child node with an 'endpoint' subnode.
+
+Example:
+
+	i2c@2000 {
+		...
+		ov: camera@36 {

Quoted 9 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 28

Quoted 5 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

+			compatible = "ovti,ov5647";
+			reg = <0x36>;
+			clocks = <&camera_clk>;
+			clock-names = "xclk";
+			clock-frequency = <25000000>;

When you remove two unused properties, please don't forget to update the example.

Quoted 11 lines

Ok.

Quoted 9 lines

Quoted 8 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +7 -0

+			port {
+				camera_1: endpoint {
+					remote-endpoint = <&csi1_ep1>;
+				};
+			};
+		};
+	};

--

With best wishes,
Vladimir

Hi, Vladimir!

How do you do? :-)

Quoted 41 lines

Hi Ramiro,

Quoted 38 lines · Ramiro Oliveira

Hi Vladimir,

Thank you for your feedback

Quoted 32 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 16 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 10 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Quoted 5 lines

Quoted 1 line

It's an external oscillator.

hmm, I suppose a clock of any type could serve as a clock for the sensor. It can be an external oscillator on a particular board, or it can be something else on another board.

Any clock source could be used I presume.

Quoted 3 lines

Can you please describe what for does ov5647 sensor need this clock, what is its function?

Camera modules (sensors) quite commonly require an external clock as they do not have an oscillator on their own. A lot of devices under Documentation/devicetree/bindings/media/i2c/ have similar properties.

Quoted 3 lines

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Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

Quoted 11 lines

Quoted 11 lines

Quoted 3 lines

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 7 lines

Quoted 3 lines

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

I doubt it, there should be no connection between a custom "clock-frequency" device tree property in a clock consumer device node and clk_get_rate() function from the CCF, which takes a clock provider as its argument.

The purpose is to make sure the clock frequency is really usable for the device, in this particular case the driver can work with one particular frequency.

That said, the driver does not appear to use the property at the moment. It should.

It'd be good to verify that the rate matches: clk_set_rate() is not guaranteed to produce the requested clock rate, and the driver could conceivably be updated with support for more frequencies. There are typically a few frequencies that a SoC such a sensor is connected can support, and 25 MHz is not one of the common frequencies. With this property, the frequency would be always there explicitly.

Hi Sakari,

Quoted 3 lines · Sakari Ailus

Hi, Vladimir!

How do you do? :-)

deferring execution of boring tasks by doing code review :)

Quoted 48 lines · Vladimir Zapolskiy

Quoted 46 lines

Hi Ramiro,

Quoted 38 lines · Ramiro Oliveira

Hi Vladimir,

Thank you for your feedback

Quoted 23 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 20 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.

Quoted 9 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 6 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +6 -0

+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Quoted 1 line

It's an external oscillator.

hmm, I suppose a clock of any type could serve as a clock for the sensor. It can be an external oscillator on a particular board, or it can be something else on another board.

Quoted 2 lines

Any clock source could be used I presume.

That's exactly my point, and it is a reason to rename "xclk" to something more generic.

Quoted 8 lines

Quoted 3 lines

Can you please describe what for does ov5647 sensor need this clock, what is its function?

Camera modules (sensors) quite commonly require an external clock as they do not have an oscillator on their own. A lot of devices under Documentation/devicetree/bindings/media/i2c/ have similar properties.

So, what should be a better replacement of "xclk" in the description above?

E.g.

- clocks : Phandle to a device supply clock.

Quoted 3 lines

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Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

We got an agreement that "clock-names" property is removed, nevertheless if it is added back, is should not be "xclk".

Quoted 26 lines

Quoted 11 lines

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Quoted 3 lines

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 7 lines

Quoted 3 lines

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

I doubt it, there should be no connection between a custom "clock-frequency" device tree property in a clock consumer device node and clk_get_rate() function from the CCF, which takes a clock provider as its argument.

The purpose is to make sure the clock frequency is really usable for the device, in this particular case the driver can work with one particular frequency.

That said, the driver does not appear to use the property at the moment. It should.

Quoted 7 lines

It'd be good to verify that the rate matches: clk_set_rate() is not guaranteed to produce the requested clock rate, and the driver could conceivably be updated with support for more frequencies. There are typically a few frequencies that a SoC such a sensor is connected can support, and 25 MHz is not one of the common frequencies. With this property, the frequency would be always there explicitly.

I can provide my arguments given at v8 review time again, since I don't see a contradiction with my older comments.

Briefly "clock-frequency" as a device tree property on a consumer side can be considered as redundant, because there is a mechanism to specify a wanted clock frequency on a clock provider side right in a board DTB.

So, the clock frequency set up is delegated to CCF, and when any other than 25 MHz frequencies are got supported, that's only the matter of driver updates, DTBs won't be touched.

Hi Vladimir

Quoted 60 lines · Vladimir Zapolskiy

Hi Sakari,

Quoted 3 lines · Sakari Ailus

Hi, Vladimir!

How do you do? :-)

deferring execution of boring tasks by doing code review :)

Quoted 50 lines · Vladimir Zapolskiy

Quoted 41 lines

Hi Ramiro,

Quoted 38 lines · Ramiro Oliveira

Hi Vladimir,

Thank you for your feedback

Quoted 32 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 16 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 10 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Quoted 5 lines

Quoted 1 line

It's an external oscillator.

hmm, I suppose a clock of any type could serve as a clock for the sensor. It can be an external oscillator on a particular board, or it can be something else on another board.

Any clock source could be used I presume.

Quoted 3 lines

That's exactly my point, and it is a reason to rename "xclk" to something more generic.

xclk it's the name being used in the camera datasheet, but I can change it to something more generic

Quoted 59 lines

Quoted 8 lines

Quoted 3 lines

Can you please describe what for does ov5647 sensor need this clock, what is its function?

Camera modules (sensors) quite commonly require an external clock as they do not have an oscillator on their own. A lot of devices under Documentation/devicetree/bindings/media/i2c/ have similar properties.

So, what should be a better replacement of "xclk" in the description above?

E.g.

- clocks : Phandle to a device supply clock.

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

We got an agreement that "clock-names" property is removed, nevertheless if it is added back, is should not be "xclk".

Quoted 26 lines

Quoted 11 lines

Quoted 11 lines

Quoted 3 lines

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 7 lines

Quoted 3 lines

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

I doubt it, there should be no connection between a custom "clock-frequency" device tree property in a clock consumer device node and clk_get_rate() function from the CCF, which takes a clock provider as its argument.

The purpose is to make sure the clock frequency is really usable for the device, in this particular case the driver can work with one particular frequency.

That said, the driver does not appear to use the property at the moment. It should.

Quoted 7 lines

It'd be good to verify that the rate matches: clk_set_rate() is not guaranteed to produce the requested clock rate, and the driver could conceivably be updated with support for more frequencies. There are typically a few frequencies that a SoC such a sensor is connected can support, and 25 MHz is not one of the common frequencies. With this property, the frequency would be always there explicitly.

I can provide my arguments given at v8 review time again, since I don't see a contradiction with my older comments.

Quoted 8 lines

Briefly "clock-frequency" as a device tree property on a consumer side can be considered as redundant, because there is a mechanism to specify a wanted clock frequency on a clock provider side right in a board DTB.

So, the clock frequency set up is delegated to CCF, and when any other than 25 MHz frequencies are got supported, that's only the matter of driver updates, DTBs won't be touched.

In the driver, I'm using this piece of code to check that the frequency is 25Mhz

	xclk_freq = clk_get_rate(sensor->xclk);
	if (xclk_freq != 25000000) {
		dev_err(dev, "Unsupported clock frequency: %u\n", xclk_freq);
		return -EINVAL;
	}

So if I don't define it here the probing will fail. Do you have another suggestion for this?

Hi Ramiro,

Quoted 63 lines · Ramiro Oliveira

Hi Vladimir

Quoted 60 lines · Vladimir Zapolskiy

Hi Sakari,

Quoted 3 lines · Sakari Ailus

Hi, Vladimir!

How do you do? :-)

deferring execution of boring tasks by doing code review :)

Quoted 50 lines · Vladimir Zapolskiy

Quoted 41 lines

Hi Ramiro,

Quoted 38 lines · Ramiro Oliveira

Hi Vladimir,

Thank you for your feedback

Quoted 32 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 16 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 10 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +10 -0

+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.
+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Quoted 5 lines

Quoted 1 line

It's an external oscillator.

hmm, I suppose a clock of any type could serve as a clock for the sensor. It can be an external oscillator on a particular board, or it can be something else on another board.

Any clock source could be used I presume.

Quoted 7 lines

Quoted 3 lines

That's exactly my point, and it is a reason to rename "xclk" to something more generic.

xclk it's the name being used in the camera datasheet, but I can change it to something more generic

Ah, if the name comes from the sensor datasheet, then it should be okay to keep it.

Quoted 70 lines

Quoted 59 lines

Quoted 8 lines

Quoted 3 lines

Can you please describe what for does ov5647 sensor need this clock, what is its function?

Camera modules (sensors) quite commonly require an external clock as they do not have an oscillator on their own. A lot of devices under Documentation/devicetree/bindings/media/i2c/ have similar properties.

So, what should be a better replacement of "xclk" in the description above?

E.g.

- clocks : Phandle to a device supply clock.

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

We got an agreement that "clock-names" property is removed, nevertheless if it is added back, is should not be "xclk".

Quoted 26 lines

Quoted 11 lines

Quoted 11 lines

Quoted 3 lines

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 7 lines

Quoted 3 lines

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

I doubt it, there should be no connection between a custom "clock-frequency" device tree property in a clock consumer device node and clk_get_rate() function from the CCF, which takes a clock provider as its argument.

The purpose is to make sure the clock frequency is really usable for the device, in this particular case the driver can work with one particular frequency.

That said, the driver does not appear to use the property at the moment. It should.

Quoted 7 lines

It'd be good to verify that the rate matches: clk_set_rate() is not guaranteed to produce the requested clock rate, and the driver could conceivably be updated with support for more frequencies. There are typically a few frequencies that a SoC such a sensor is connected can support, and 25 MHz is not one of the common frequencies. With this property, the frequency would be always there explicitly.

I can provide my arguments given at v8 review time again, since I don't see a contradiction with my older comments.

Quoted 8 lines

Briefly "clock-frequency" as a device tree property on a consumer side can be considered as redundant, because there is a mechanism to specify a wanted clock frequency on a clock provider side right in a board DTB.

So, the clock frequency set up is delegated to CCF, and when any other than 25 MHz frequencies are got supported, that's only the matter of driver updates, DTBs won't be touched.

In the driver, I'm using this piece of code to check that the frequency is 25Mhz

Quoted 9 lines

	xclk_freq = clk_get_rate(sensor->xclk);
	if (xclk_freq != 25000000) {
		dev_err(dev, "Unsupported clock frequency: %u\n", xclk_freq);
		return -EINVAL;
	}

So if I don't define it here the probing will fail. Do you have another suggestion for this?

I don't completely understand, why does it fail? "clock-frequency" property is not a standard device node property on a clock consumer side, so, if we're still talking about v9 version of the driver, adding the property or removing it should have no effect.

Let's consider the simplest possible situation, when "xclk" is actually a fixed rate 25MHz oscillator (the clock device node is "fixed-clock" compatible), for such a clock clk_get_rate() returns 25MHz rate, the assert has to be passed. In case of a more complex scenario please reference to clock-bindings.txt documentation, in particular please take a look at "assigned-clocks" and "assigned-clock-rates" properties.

Hi Sakari,

Quoted 3 lines · Sakari Ailus

Hi, Vladimir!

How do you do? :-)

deferring execution of boring tasks by doing code review :)

Quoted 49 lines · Vladimir Zapolskiy

Quoted 46 lines

Hi Ramiro,

Quoted 38 lines · Ramiro Oliveira

Hi Vladimir,

Thank you for your feedback

Quoted 23 lines · Vladimir Zapolskiy

Hi Ramiro,

Quoted 20 lines · Ramiro Oliveira

Create device tree bindings documentation.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

Acked-by Rob Herring <[email protected]>

---
 .../devicetree/bindings/media/i2c/ov5647.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5647.txt

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +5 -0

new file mode 100644
index 000000000000..31956426d3b9
@@ -0,0 +1,35 @@
+Omnivision OV5647 raw image sensor
+---------------------------------
+
+OV5647 is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces
+and CCI (I2C compatible) control bus.

Quoted 9 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 11

Quoted 6 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +6 -0

+
+Required properties:
+
+- compatible		: "ovti,ov5647".
+- reg			: I2C slave address of the sensor.
+- clocks		: Reference to the xclk clock.

Is "xclk" clock a pixel clock or something else?

Quoted 1 line

It's an external oscillator.

hmm, I suppose a clock of any type could serve as a clock for the sensor. It can be an external oscillator on a particular board, or it can be something else on another board.

Quoted 2 lines

Any clock source could be used I presume.

That's exactly my point, and it is a reason to rename "xclk" to something more generic.

Quoted 9 lines

Quoted 4 lines

Can you please describe what for does ov5647 sensor need this clock, what is its function?

Camera modules (sensors) quite commonly require an external clock as they do not have an oscillator on their own. A lot of devices under Documentation/devicetree/bindings/media/i2c/ have similar properties.

So, what should be a better replacement of "xclk" in the description above?

E.g.

- clocks : Phandle to a device supply clock.

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 12

Quoted 3 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-names		: Should be "xclk".

We got an agreement that "clock-names" property is removed, nevertheless if it is added back, is should not be "xclk".

Quoted 26 lines

Quoted 11 lines

Quoted 11 lines

Quoted 3 lines

You can remove this property, because there is only one source clock.

Ok.

Quoted 4 lines

Documentation/devicetree/bindings/media/i2c/ov5647.txt line 13

Quoted 1 line

Documentation/devicetree/bindings/media/i2c/ov5647.txt new file +1 -0

+- clock-frequency	: Frequency of the xclk clock.

And after the last updates in the driver this property can be removed as well.

Quoted 7 lines

Quoted 3 lines

But I'm still using clk_get_rate in the driver, if I remove the frequency here the probing will fail.

I doubt it, there should be no connection between a custom "clock-frequency" device tree property in a clock consumer device node and clk_get_rate() function from the CCF, which takes a clock provider as its argument.

The purpose is to make sure the clock frequency is really usable for the device, in this particular case the driver can work with one particular frequency.

That said, the driver does not appear to use the property at the moment. It should.

Quoted 7 lines

It'd be good to verify that the rate matches: clk_set_rate() is not guaranteed to produce the requested clock rate, and the driver could conceivably be updated with support for more frequencies. There are typically a few frequencies that a SoC such a sensor is connected can support, and 25 MHz is not one of the common frequencies. With this property, the frequency would be always there explicitly.

I can provide my arguments given at v8 review time again, since I don't see a contradiction with my older comments.

Briefly "clock-frequency" as a device tree property on a consumer side can be considered as redundant, because there is a mechanism to specify a wanted clock frequency on a clock provider side right in a board DTB.

So, the clock frequency set up is delegated to CCF, and when any other than 25 MHz frequencies are got supported, that's only the matter of driver updates, DTBs won't be touched.

Although, the driver could try to work on the actual obtained frequency. This is unlikely to work though, but it won't be very easy to figure out why the device isn't working. Having the frequency in DT accessible for the driver to check makes failing early with a clear error message possible.

Quoted 5 lines

So, the clock frequency set up is delegated to CCF, and when any other than 25 MHz frequencies are got supported, that's only the matter of driver updates, DTBs won't be touched.

Indeed. The new supported frequencies in this case will be additional single values; there won't be ranges or such. The register lists the driver contains are more or less dependent on that frequency.

The OV5647 sensor from Omnivision supports up to 2592x1944 @ 15 fps, RAW 8 and RAW 10 output formats, and MIPI CSI-2 interface.

The driver adds support for 640x480 RAW 8.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

---
 MAINTAINERS                |   7 +
 drivers/media/i2c/Kconfig  |  11 +
 drivers/media/i2c/Makefile |   1 +
 drivers/media/i2c/ov5647.c | 638 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 657 insertions(+)
 create mode 100644 drivers/media/i2c/ov5647.c

MAINTAINERS +7 -0

index 8e7e8d7855ee..7bbca271acc8 100644
@@ -9109,6 +9109,13 @@ M:	Harald Welte <[email protected]>
 S:	Maintained
 F:	drivers/char/pcmcia/cm4040_cs.*
 
+OMNIVISION OV5647 SENSOR DRIVER
+M:	Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>
+L:	[email protected]
+T:	git git://linuxtv.org/media_tree.git
+S:	Maintained
+F:	drivers/media/i2c/ov5647.c
+
 OMNIVISION OV7670 SENSOR DRIVER
 M:	Jonathan Corbet <[email protected]>
 L:	[email protected]

drivers/media/i2c/Kconfig +11 -0

index cee1dae6e014..8435b99f38bc 100644
@@ -531,6 +531,17 @@ config VIDEO_OV2659
 	  To compile this driver as a module, choose M here: the
 	  module will be called ov2659.
 
+config VIDEO_OV5647
+	tristate "OmniVision OV5647 sensor support"
+	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+	depends on MEDIA_CAMERA_SUPPORT
+	---help---
+	  This is a Video4Linux2 sensor-level driver for the OmniVision
+	  OV5647 camera.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ov5647.
+
 config VIDEO_OV7640
 	tristate "OmniVision OV7640 sensor support"
 	depends on I2C && VIDEO_V4L2

drivers/media/i2c/Makefile +1 -0

index 5bc7bbeb5499..ef2ccf65f94c 100644
@@ -83,3 +83,4 @@ obj-$(CONFIG_VIDEO_IR_I2C)  += ir-kbd-i2c.o
 obj-$(CONFIG_VIDEO_ML86V7667)	+= ml86v7667.o
 obj-$(CONFIG_VIDEO_OV2659)	+= ov2659.o
 obj-$(CONFIG_VIDEO_TC358743)	+= tc358743.o
+obj-$(CONFIG_VIDEO_OV5647)	+= ov5647.o

drivers/media/i2c/ov5647.c new file +20 -0

new file mode 100644
index 000000000000..34e620fabbaf
@@ -0,0 +1,638 @@
+/*
+ * A V4L2 driver for OmniVision OV5647 cameras.
+ *
+ * Based on Samsung S5K6AAFX SXGA 1/6" 1.3M CMOS Image Sensor driver
+ * Copyright (C) 2011 Sylwester Nawrocki <[email protected]>
+ *
+ * Based on Omnivision OV7670 Camera Driver
+ * Copyright (C) 2006-7 Jonathan Corbet <[email protected]>
+ *
+ * Copyright (C) 2016, Synopsys, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed .as is. WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */

drivers/media/i2c/ov5647.c new file +298 -0

+#include <media/v4l2-device.h>
+#include <media/v4l2-image-sizes.h>
+#include <media/v4l2-mediabus.h>
+#include <media/v4l2-of.h>
+
+#define SENSOR_NAME "ov5647"
+
+#define OV5647_SW_RESET		0x1003
+#define OV5647_REG_CHIPID_H	0x300A
+#define OV5647_REG_CHIPID_L	0x300B
+
+#define REG_TERM 0xfffe
+#define VAL_TERM 0xfe
+#define REG_DLY  0xffff
+
+#define OV5647_ROW_START		0x01
+#define OV5647_ROW_START_MIN		0
+#define OV5647_ROW_START_MAX		2004
+#define OV5647_ROW_START_DEF		54
+
+#define OV5647_COLUMN_START		0x02
+#define OV5647_COLUMN_START_MIN		0
+#define OV5647_COLUMN_START_MAX		2750
+#define OV5647_COLUMN_START_DEF		16
+
+#define OV5647_WINDOW_HEIGHT		0x03
+#define OV5647_WINDOW_HEIGHT_MIN	2
+#define OV5647_WINDOW_HEIGHT_MAX	2006
+#define OV5647_WINDOW_HEIGHT_DEF	1944
+
+#define OV5647_WINDOW_WIDTH		0x04
+#define OV5647_WINDOW_WIDTH_MIN		2
+#define OV5647_WINDOW_WIDTH_MAX		2752
+#define OV5647_WINDOW_WIDTH_DEF		2592
+
+struct regval_list {
+	u16 addr;
+	u8 data;
+};
+
+struct ov5647 {
+	struct v4l2_subdev		sd;
+	struct media_pad		pad;
+	struct mutex			lock;
+	struct v4l2_mbus_framefmt	format;
+	unsigned int			width;
+	unsigned int			height;
+	int				power_count;
+	struct clk			*xclk;
+	/* External clock frequency currently supported is 30MHz */
+	u32				xclk_freq;
+};
+
+static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct ov5647, sd);
+}
+
+static struct regval_list sensor_oe_disable_regs[] = {
+	{0x3000, 0x00},
+	{0x3001, 0x00},
+	{0x3002, 0x00},
+};
+
+static struct regval_list sensor_oe_enable_regs[] = {
+	{0x3000, 0x0f},
+	{0x3001, 0xff},
+	{0x3002, 0xe4},
+};
+
+static struct regval_list ov5647_640x480[] = {
+	{0x0100, 0x00},
+	{0x0103, 0x01},
+	{0x3034, 0x08},
+	{0x3035, 0x21},
+	{0x3036, 0x46},
+	{0x303c, 0x11},
+	{0x3106, 0xf5},
+	{0x3821, 0x07},
+	{0x3820, 0x41},
+	{0x3827, 0xec},
+	{0x370c, 0x0f},
+	{0x3612, 0x59},
+	{0x3618, 0x00},
+	{0x5000, 0x06},
+	{0x5001, 0x01},
+	{0x5002, 0x41},
+	{0x5003, 0x08},
+	{0x5a00, 0x08},
+	{0x3000, 0x00},
+	{0x3001, 0x00},
+	{0x3002, 0x00},
+	{0x3016, 0x08},
+	{0x3017, 0xe0},
+	{0x3018, 0x44},
+	{0x301c, 0xf8},
+	{0x301d, 0xf0},
+	{0x3a18, 0x00},
+	{0x3a19, 0xf8},
+	{0x3c01, 0x80},
+	{0x3b07, 0x0c},
+	{0x380c, 0x07},
+	{0x380d, 0x68},
+	{0x380e, 0x03},
+	{0x380f, 0xd8},
+	{0x3814, 0x31},
+	{0x3815, 0x31},
+	{0x3708, 0x64},
+	{0x3709, 0x52},
+	{0x3808, 0x02},
+	{0x3809, 0x80},
+	{0x380a, 0x01},
+	{0x380b, 0xE0},
+	{0x3801, 0x00},
+	{0x3802, 0x00},
+	{0x3803, 0x00},
+	{0x3804, 0x0a},
+	{0x3805, 0x3f},
+	{0x3806, 0x07},
+	{0x3807, 0xa1},
+	{0x3811, 0x08},
+	{0x3813, 0x02},
+	{0x3630, 0x2e},
+	{0x3632, 0xe2},
+	{0x3633, 0x23},
+	{0x3634, 0x44},
+	{0x3636, 0x06},
+	{0x3620, 0x64},
+	{0x3621, 0xe0},
+	{0x3600, 0x37},
+	{0x3704, 0xa0},
+	{0x3703, 0x5a},
+	{0x3715, 0x78},
+	{0x3717, 0x01},
+	{0x3731, 0x02},
+	{0x370b, 0x60},
+	{0x3705, 0x1a},
+	{0x3f05, 0x02},
+	{0x3f06, 0x10},
+	{0x3f01, 0x0a},
+	{0x3a08, 0x01},
+	{0x3a09, 0x27},
+	{0x3a0a, 0x00},
+	{0x3a0b, 0xf6},
+	{0x3a0d, 0x04},
+	{0x3a0e, 0x03},
+	{0x3a0f, 0x58},
+	{0x3a10, 0x50},
+	{0x3a1b, 0x58},
+	{0x3a1e, 0x50},
+	{0x3a11, 0x60},
+	{0x3a1f, 0x28},
+	{0x4001, 0x02},
+	{0x4004, 0x02},
+	{0x4000, 0x09},
+	{0x4837, 0x24},
+	{0x4050, 0x6e},
+	{0x4051, 0x8f},
+	{0x0100, 0x01},
+};
+
+static int ov5647_write(struct v4l2_subdev *sd, u16 reg, u8 val)
+{
+	int ret;
+	unsigned char data[3] = { reg >> 8, reg & 0xff, val};
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = i2c_master_send(client, data, 3);
+	if (ret < 0)
+		dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
+				__func__, reg);
+
+	return ret;
+}
+
+static int ov5647_read(struct v4l2_subdev *sd, u16 reg, u8 *val)
+{
+	int ret;
+	unsigned char data_w[2] = { reg >> 8, reg & 0xff };
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = i2c_master_send(client, data_w, 2);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
+			__func__, reg);
+		return ret;
+	}
+
+	ret = i2c_master_recv(client, val, 1);
+	if (ret < 0)
+		dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
+				__func__, reg);
+
+	return ret;
+
+}
+
+static int ov5647_write_array(struct v4l2_subdev *sd,
+				struct regval_list *regs, int array_size)
+{
+	int i = 0, ret;
+
+	for (i = 0; i < array_size; i++) {
+		ret = ov5647_write(sd, regs[i].addr, regs[i].data);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
+{
+	u8 channel_id;
+	int ret;
+
+	ret = ov5647_read(sd, 0x4814, &channel_id);
+	if (ret < 0)
+		return ret;
+
+	channel_id &= ~(3 << 6);
+	return ov5647_write(sd, 0x4814, channel_id | (channel << 6));
+}
+
+static int ov5647_stream_on(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ov5647_write(sd, 0x4202, 0x00);
+
+	dev_dbg(&client->dev, "Stream on");
+
+	return ov5647_write(sd, 0x300D, 0x00);
+}
+
+static int ov5647_stream_off(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ov5647_write(sd, 0x4202, 0x0f);
+
+	dev_dbg(&client->dev, "Stream off");
+
+	return ov5647_write(sd, 0x300D, 0x01);
+}
+
+static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
+{
+	int ret;
+	u8 rdval;
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	if (standby)
+		rdval &= ~0x01;
+	else
+		rdval |= 0x01;
+
+	return ov5647_write(sd, 0x0100, rdval);
+}
+
+static int __sensor_init(struct v4l2_subdev *sd)
+{
+	int ret;
+	u8 resetval;
+	u8 rdval;
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	dev_dbg(&client->dev, "sensor init\n");
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_write_array(sd, ov5647_640x480,
+					ARRAY_SIZE(ov5647_640x480));
+	if (ret < 0) {
+		dev_err(&client->dev, "write sensor default regs error\n");
+		return ret;
+	}
+
+	ret = ov5647_set_virtual_channel(sd, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_read(sd, 0x0100, &resetval);
+	if (ret < 0)
+		return ret;
+
+	if (!(resetval & 0x01)) {
+		dev_err(&client->dev, "Device was in SW standby");
+		ret = ov5647_write(sd, 0x0100, 0x01);
+		if (ret < 0)
+			return ret;
+	}
+

drivers/media/i2c/ov5647.c new file +136 -0

+	mutex_lock(&ov5647->lock);
+
+	if (on && !ov5647->power_count)	{
+		dev_dbg(&client->dev, "OV5647 power on\n");
+
+		clk_set_rate(ov5647->xclk, ov5647->xclk_freq);
+
+		ret = clk_prepare_enable(ov5647->xclk);
+		if (ret < 0) {
+			dev_err(&client->dev, "clk prepare enable failed\n");
+			goto out;
+		}
+
+		ret = ov5647_write_array(sd, sensor_oe_enable_regs,
+				ARRAY_SIZE(sensor_oe_enable_regs));
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"write sensor_oe_enable_regs error\n");
+			goto out;
+		}
+
+		ret = __sensor_init(sd);
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"Camera not available, check Power\n");
+			goto out;
+		}
+	} else if (!on && ov5647->power_count == 1) {
+		dev_dbg(&client->dev, "OV5647 power off\n");
+
+		dev_dbg(&client->dev, "disable oe\n");
+		ret = ov5647_write_array(sd, sensor_oe_disable_regs,
+				ARRAY_SIZE(sensor_oe_disable_regs));
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "disable oe failed\n");
+
+		ret = set_sw_standby(sd, true);
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "soft stby failed\n");
+
+		clk_disable_unprepare(ov5647->xclk);
+	}
+
+	/* Update the power count. */
+	ov5647->power_count += on ? 1 : -1;
+	WARN_ON(ov5647->power_count < 0);
+
+out:
+	mutex_unlock(&ov5647->lock);
+
+	return ret;
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int sensor_get_register(struct v4l2_subdev *sd,
+				struct v4l2_dbg_register *reg)
+{
+	u8 val;
+	int ret;
+
+	ret = ov5647_read(sd, reg->reg & 0xff, &val);
+	if (ret < 0)
+		return ret;
+
+	reg->val = val;
+	reg->size = 1;
+
+	return 0;
+}
+
+static int sensor_set_register(struct v4l2_subdev *sd,
+				const struct v4l2_dbg_register *reg)
+{
+	return ov5647_write(sd, reg->reg & 0xff, reg->val & 0xff);
+}
+#endif
+
+/**
+ * @short Subdev core operations registration
+ */
+static const struct v4l2_subdev_core_ops subdev_core_ops = {
+	.s_power		= sensor_power,
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register		= sensor_get_register,
+	.s_register		= sensor_set_register,
+#endif
+};
+
+static int s_stream(struct v4l2_subdev *sd, int enable)
+{
+	if (enable)
+		return ov5647_stream_on(sd);
+	else
+		return ov5647_stream_off(sd);
+}
+
+static const struct v4l2_subdev_video_ops subdev_video_ops = {
+	.s_stream =		s_stream,
+};
+
+static int enum_mbus_code(struct v4l2_subdev *sd,
+				struct v4l2_subdev_pad_config *cfg,
+				struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index > 0)
+		return -EINVAL;
+
+	code->code = MEDIA_BUS_FMT_SBGGR8_1X8;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops subdev_pad_ops = {
+	.enum_mbus_code =	enum_mbus_code,
+};
+
+/**
+ * @short Subdev operations registration
+ *
+ */
+static const struct v4l2_subdev_ops subdev_ops = {
+	.core		= &subdev_core_ops,
+	.video		= &subdev_video_ops,
+	.pad		= &subdev_pad_ops,
+};
+
+static int ov5647_detect(struct v4l2_subdev *sd)
+{
+	u8 read;
+	int ret;
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+

drivers/media/i2c/ov5647.c new file +9 -0

+		return -ENODEV;
+	}
+
+	ret = ov5647_read(sd, OV5647_REG_CHIPID_L, &read);
+	if (ret < 0)
+		return ret;
+
+	if (read != 0x47) {
+		dev_err(&client->dev, "Wrong model version detected");

drivers/media/i2c/ov5647.c new file +135 -0

+
+static int ov5647_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	struct v4l2_mbus_framefmt *format =
+				v4l2_subdev_get_try_format(sd, fh->pad, 0);
+	struct v4l2_rect *crop =
+				v4l2_subdev_get_try_crop(sd, fh->pad, 0);
+
+	crop->left = OV5647_COLUMN_START_DEF;
+	crop->top = OV5647_ROW_START_DEF;
+	crop->width = OV5647_WINDOW_WIDTH_DEF;
+	crop->height = OV5647_WINDOW_HEIGHT_DEF;
+
+	format->code = MEDIA_BUS_FMT_SBGGR8_1X8;
+
+	format->width = OV5647_WINDOW_WIDTH_DEF;
+	format->height = OV5647_WINDOW_HEIGHT_DEF;
+	format->field = V4L2_FIELD_NONE;
+	format->colorspace = V4L2_COLORSPACE_SRGB;
+
+	return sensor_power(sd, true);
+}
+
+static int ov5647_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	return sensor_power(sd, false);
+}
+
+/**
+ * @short Subdev internal operations registration
+ *
+ */
+static const struct v4l2_subdev_internal_ops ov5647_subdev_internal_ops = {
+	.registered = ov5647_registered,
+	.open = ov5647_open,
+	.close = ov5647_close,
+};
+
+static int ov5647_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ov5647 *sensor;
+	int ret;
+	struct v4l2_subdev *sd;
+
+	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
+	if (sensor == NULL)
+		return -ENOMEM;
+
+	/* get system clock (xclk) */
+	sensor->xclk = devm_clk_get(dev, "xclk");
+	if (IS_ERR(sensor->xclk)) {
+		dev_err(dev, "could not get xclk");
+		return PTR_ERR(sensor->xclk);
+	}
+
+	sensor->xclk_freq = clk_get_rate(sensor->xclk);
+	if (sensor->xclk_freq != 25000000) {
+		dev_err(dev, "Unsupported clock frequency: %u\n",
+			sensor->xclk_freq);
+		return -EINVAL;
+	}
+
+	mutex_init(&sensor->lock);
+
+	sd = &sensor->sd;
+	v4l2_i2c_subdev_init(sd, client, &subdev_ops);
+	sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
+	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	ret = media_entity_pads_init(&sd->entity, 1, &sensor->pad);
+	if (ret < 0)
+		goto mutex_remove;
+
+	ret = ov5647_detect(sd);
+	if (ret < 0)
+		goto error;
+
+	ret = v4l2_async_register_subdev(sd);
+	if (ret < 0)
+		goto error;
+
+	dev_dbg(&client->dev, "OmniVision OV5647 camera driver probed\n");
+	return 0;
+error:
+	media_entity_cleanup(&sd->entity);
+mutex_remove:
+	mutex_destroy(&sensor->lock);
+	return ret;
+}
+
+static int ov5647_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov5647 *ov5647 = to_state(sd);
+
+	v4l2_async_unregister_subdev(&ov5647->sd);
+	media_entity_cleanup(&ov5647->sd.entity);
+	v4l2_device_unregister_subdev(sd);
+	mutex_destroy(&ov5647->lock);
+
+	return 0;
+}
+
+static const struct i2c_device_id ov5647_id[] = {
+	{ "ov5647", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ov5647_id);
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id ov5647_of_match[] = {
+	{ .compatible = "ovti,ov5647" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ov5647_of_match);
+#endif
+
+static struct i2c_driver ov5647_driver = {
+	.driver = {
+		.of_match_table = of_match_ptr(ov5647_of_match),
+		.name	= SENSOR_NAME,
+	},
+	.probe		= ov5647_probe,
+	.remove		= ov5647_remove,
+	.id_table	= ov5647_id,
+};
+
+module_i2c_driver(ov5647_driver);
+
+MODULE_AUTHOR("Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>");
+MODULE_DESCRIPTION("A low-level driver for OmniVision ov5647 sensors");
+MODULE_LICENSE("GPL v2");

Hi Ramiro,

A few minor comments below.

Quoted 89 lines · Ramiro Oliveira

The OV5647 sensor from Omnivision supports up to 2592x1944 @ 15 fps, RAW 8 and RAW 10 output formats, and MIPI CSI-2 interface.

The driver adds support for 640x480 RAW 8.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

---
 MAINTAINERS                |   7 +
 drivers/media/i2c/Kconfig  |  11 +
 drivers/media/i2c/Makefile |   1 +
 drivers/media/i2c/ov5647.c | 638 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 657 insertions(+)
 create mode 100644 drivers/media/i2c/ov5647.c

MAINTAINERS +7 -0

index 8e7e8d7855ee..7bbca271acc8 100644
@@ -9109,6 +9109,13 @@ M:	Harald Welte <[email protected]>
 S:	Maintained
 F:	drivers/char/pcmcia/cm4040_cs.*
 
+OMNIVISION OV5647 SENSOR DRIVER
+M:	Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>
+L:	[email protected]
+T:	git git://linuxtv.org/media_tree.git
+S:	Maintained
+F:	drivers/media/i2c/ov5647.c
+
 OMNIVISION OV7670 SENSOR DRIVER
 M:	Jonathan Corbet <[email protected]>
 L:	[email protected]

drivers/media/i2c/Kconfig +11 -0

index cee1dae6e014..8435b99f38bc 100644
@@ -531,6 +531,17 @@ config VIDEO_OV2659
 	  To compile this driver as a module, choose M here: the
 	  module will be called ov2659.
 
+config VIDEO_OV5647
+	tristate "OmniVision OV5647 sensor support"
+	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+	depends on MEDIA_CAMERA_SUPPORT
+	---help---
+	  This is a Video4Linux2 sensor-level driver for the OmniVision
+	  OV5647 camera.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ov5647.
+
 config VIDEO_OV7640
 	tristate "OmniVision OV7640 sensor support"
 	depends on I2C && VIDEO_V4L2

drivers/media/i2c/Makefile +1 -0

index 5bc7bbeb5499..ef2ccf65f94c 100644
@@ -83,3 +83,4 @@ obj-$(CONFIG_VIDEO_IR_I2C)  += ir-kbd-i2c.o
 obj-$(CONFIG_VIDEO_ML86V7667)	+= ml86v7667.o
 obj-$(CONFIG_VIDEO_OV2659)	+= ov2659.o
 obj-$(CONFIG_VIDEO_TC358743)	+= tc358743.o
+obj-$(CONFIG_VIDEO_OV5647)	+= ov5647.o

drivers/media/i2c/ov5647.c new file +20 -0

new file mode 100644
index 000000000000..34e620fabbaf
@@ -0,0 +1,638 @@
+/*
+ * A V4L2 driver for OmniVision OV5647 cameras.
+ *
+ * Based on Samsung S5K6AAFX SXGA 1/6" 1.3M CMOS Image Sensor driver
+ * Copyright (C) 2011 Sylwester Nawrocki <[email protected]>
+ *
+ * Based on Omnivision OV7670 Camera Driver
+ * Copyright (C) 2006-7 Jonathan Corbet <[email protected]>
+ *
+ * Copyright (C) 2016, Synopsys, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed .as is. WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */

drivers/media/i2c/ov5647.c line 30

Quoted 10 lines

drivers/media/i2c/ov5647.c new file +10 -0

+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-ctrls.h>

You don't seem to implement any controls.

The sensor likely supports exposure time (and maybe also gain) the user might want to control. Is there an intent to add that? Otherwise the header should be removed.

Quoted 302 lines

drivers/media/i2c/ov5647.c new file +302 -0

+#include <media/v4l2-device.h>
+#include <media/v4l2-image-sizes.h>
+#include <media/v4l2-mediabus.h>
+#include <media/v4l2-of.h>
+
+#define SENSOR_NAME "ov5647"
+
+#define OV5647_SW_RESET		0x1003
+#define OV5647_REG_CHIPID_H	0x300A
+#define OV5647_REG_CHIPID_L	0x300B
+
+#define REG_TERM 0xfffe
+#define VAL_TERM 0xfe
+#define REG_DLY  0xffff
+
+#define OV5647_ROW_START		0x01
+#define OV5647_ROW_START_MIN		0
+#define OV5647_ROW_START_MAX		2004
+#define OV5647_ROW_START_DEF		54
+
+#define OV5647_COLUMN_START		0x02
+#define OV5647_COLUMN_START_MIN		0
+#define OV5647_COLUMN_START_MAX		2750
+#define OV5647_COLUMN_START_DEF		16
+
+#define OV5647_WINDOW_HEIGHT		0x03
+#define OV5647_WINDOW_HEIGHT_MIN	2
+#define OV5647_WINDOW_HEIGHT_MAX	2006
+#define OV5647_WINDOW_HEIGHT_DEF	1944
+
+#define OV5647_WINDOW_WIDTH		0x04
+#define OV5647_WINDOW_WIDTH_MIN		2
+#define OV5647_WINDOW_WIDTH_MAX		2752
+#define OV5647_WINDOW_WIDTH_DEF		2592
+
+struct regval_list {
+	u16 addr;
+	u8 data;
+};
+
+struct ov5647 {
+	struct v4l2_subdev		sd;
+	struct media_pad		pad;
+	struct mutex			lock;
+	struct v4l2_mbus_framefmt	format;
+	unsigned int			width;
+	unsigned int			height;
+	int				power_count;
+	struct clk			*xclk;
+	/* External clock frequency currently supported is 30MHz */
+	u32				xclk_freq;
+};
+
+static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct ov5647, sd);
+}
+
+static struct regval_list sensor_oe_disable_regs[] = {
+	{0x3000, 0x00},
+	{0x3001, 0x00},
+	{0x3002, 0x00},
+};
+
+static struct regval_list sensor_oe_enable_regs[] = {
+	{0x3000, 0x0f},
+	{0x3001, 0xff},
+	{0x3002, 0xe4},
+};
+
+static struct regval_list ov5647_640x480[] = {
+	{0x0100, 0x00},
+	{0x0103, 0x01},
+	{0x3034, 0x08},
+	{0x3035, 0x21},
+	{0x3036, 0x46},
+	{0x303c, 0x11},
+	{0x3106, 0xf5},
+	{0x3821, 0x07},
+	{0x3820, 0x41},
+	{0x3827, 0xec},
+	{0x370c, 0x0f},
+	{0x3612, 0x59},
+	{0x3618, 0x00},
+	{0x5000, 0x06},
+	{0x5001, 0x01},
+	{0x5002, 0x41},
+	{0x5003, 0x08},
+	{0x5a00, 0x08},
+	{0x3000, 0x00},
+	{0x3001, 0x00},
+	{0x3002, 0x00},
+	{0x3016, 0x08},
+	{0x3017, 0xe0},
+	{0x3018, 0x44},
+	{0x301c, 0xf8},
+	{0x301d, 0xf0},
+	{0x3a18, 0x00},
+	{0x3a19, 0xf8},
+	{0x3c01, 0x80},
+	{0x3b07, 0x0c},
+	{0x380c, 0x07},
+	{0x380d, 0x68},
+	{0x380e, 0x03},
+	{0x380f, 0xd8},
+	{0x3814, 0x31},
+	{0x3815, 0x31},
+	{0x3708, 0x64},
+	{0x3709, 0x52},
+	{0x3808, 0x02},
+	{0x3809, 0x80},
+	{0x380a, 0x01},
+	{0x380b, 0xE0},
+	{0x3801, 0x00},
+	{0x3802, 0x00},
+	{0x3803, 0x00},
+	{0x3804, 0x0a},
+	{0x3805, 0x3f},
+	{0x3806, 0x07},
+	{0x3807, 0xa1},
+	{0x3811, 0x08},
+	{0x3813, 0x02},
+	{0x3630, 0x2e},
+	{0x3632, 0xe2},
+	{0x3633, 0x23},
+	{0x3634, 0x44},
+	{0x3636, 0x06},
+	{0x3620, 0x64},
+	{0x3621, 0xe0},
+	{0x3600, 0x37},
+	{0x3704, 0xa0},
+	{0x3703, 0x5a},
+	{0x3715, 0x78},
+	{0x3717, 0x01},
+	{0x3731, 0x02},
+	{0x370b, 0x60},
+	{0x3705, 0x1a},
+	{0x3f05, 0x02},
+	{0x3f06, 0x10},
+	{0x3f01, 0x0a},
+	{0x3a08, 0x01},
+	{0x3a09, 0x27},
+	{0x3a0a, 0x00},
+	{0x3a0b, 0xf6},
+	{0x3a0d, 0x04},
+	{0x3a0e, 0x03},
+	{0x3a0f, 0x58},
+	{0x3a10, 0x50},
+	{0x3a1b, 0x58},
+	{0x3a1e, 0x50},
+	{0x3a11, 0x60},
+	{0x3a1f, 0x28},
+	{0x4001, 0x02},
+	{0x4004, 0x02},
+	{0x4000, 0x09},
+	{0x4837, 0x24},
+	{0x4050, 0x6e},
+	{0x4051, 0x8f},
+	{0x0100, 0x01},
+};
+
+static int ov5647_write(struct v4l2_subdev *sd, u16 reg, u8 val)
+{
+	int ret;
+	unsigned char data[3] = { reg >> 8, reg & 0xff, val};
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = i2c_master_send(client, data, 3);
+	if (ret < 0)
+		dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
+				__func__, reg);
+
+	return ret;
+}
+
+static int ov5647_read(struct v4l2_subdev *sd, u16 reg, u8 *val)
+{
+	int ret;
+	unsigned char data_w[2] = { reg >> 8, reg & 0xff };
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = i2c_master_send(client, data_w, 2);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
+			__func__, reg);
+		return ret;
+	}
+
+	ret = i2c_master_recv(client, val, 1);
+	if (ret < 0)
+		dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
+				__func__, reg);
+
+	return ret;
+
+}
+
+static int ov5647_write_array(struct v4l2_subdev *sd,
+				struct regval_list *regs, int array_size)
+{
+	int i = 0, ret;
+
+	for (i = 0; i < array_size; i++) {
+		ret = ov5647_write(sd, regs[i].addr, regs[i].data);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
+{
+	u8 channel_id;
+	int ret;
+
+	ret = ov5647_read(sd, 0x4814, &channel_id);
+	if (ret < 0)
+		return ret;
+
+	channel_id &= ~(3 << 6);
+	return ov5647_write(sd, 0x4814, channel_id | (channel << 6));
+}
+
+static int ov5647_stream_on(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ov5647_write(sd, 0x4202, 0x00);
+
+	dev_dbg(&client->dev, "Stream on");
+
+	return ov5647_write(sd, 0x300D, 0x00);
+}
+
+static int ov5647_stream_off(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ov5647_write(sd, 0x4202, 0x0f);
+
+	dev_dbg(&client->dev, "Stream off");
+
+	return ov5647_write(sd, 0x300D, 0x01);
+}
+
+static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
+{
+	int ret;
+	u8 rdval;
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	if (standby)
+		rdval &= ~0x01;
+	else
+		rdval |= 0x01;
+
+	return ov5647_write(sd, 0x0100, rdval);
+}
+
+static int __sensor_init(struct v4l2_subdev *sd)
+{
+	int ret;
+	u8 resetval;
+	u8 rdval;
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	dev_dbg(&client->dev, "sensor init\n");
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_write_array(sd, ov5647_640x480,
+					ARRAY_SIZE(ov5647_640x480));
+	if (ret < 0) {
+		dev_err(&client->dev, "write sensor default regs error\n");
+		return ret;
+	}
+
+	ret = ov5647_set_virtual_channel(sd, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_read(sd, 0x0100, &resetval);
+	if (ret < 0)
+		return ret;
+
+	if (!(resetval & 0x01)) {
+		dev_err(&client->dev, "Device was in SW standby");
+		ret = ov5647_write(sd, 0x0100, 0x01);
+		if (ret < 0)
+			return ret;
+	}
+
+	return ov5647_write(sd, 0x4800, 0x04);
+}
+
+static int sensor_power(struct v4l2_subdev *sd, int on)

drivers/media/i2c/ov5647.c line 338

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+{
+	int ret;
+	struct ov5647 *ov5647 = to_state(sd);
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = 0;

You can assign in variable declaration.

Quoted 141 lines

drivers/media/i2c/ov5647.c new file +141 -0

+	mutex_lock(&ov5647->lock);
+
+	if (on && !ov5647->power_count)	{
+		dev_dbg(&client->dev, "OV5647 power on\n");
+
+		clk_set_rate(ov5647->xclk, ov5647->xclk_freq);
+
+		ret = clk_prepare_enable(ov5647->xclk);
+		if (ret < 0) {
+			dev_err(&client->dev, "clk prepare enable failed\n");
+			goto out;
+		}
+
+		ret = ov5647_write_array(sd, sensor_oe_enable_regs,
+				ARRAY_SIZE(sensor_oe_enable_regs));
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"write sensor_oe_enable_regs error\n");
+			goto out;
+		}
+
+		ret = __sensor_init(sd);
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"Camera not available, check Power\n");
+			goto out;
+		}
+	} else if (!on && ov5647->power_count == 1) {
+		dev_dbg(&client->dev, "OV5647 power off\n");
+
+		dev_dbg(&client->dev, "disable oe\n");
+		ret = ov5647_write_array(sd, sensor_oe_disable_regs,
+				ARRAY_SIZE(sensor_oe_disable_regs));
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "disable oe failed\n");
+
+		ret = set_sw_standby(sd, true);
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "soft stby failed\n");
+
+		clk_disable_unprepare(ov5647->xclk);
+	}
+
+	/* Update the power count. */
+	ov5647->power_count += on ? 1 : -1;
+	WARN_ON(ov5647->power_count < 0);
+
+out:
+	mutex_unlock(&ov5647->lock);
+
+	return ret;
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int sensor_get_register(struct v4l2_subdev *sd,
+				struct v4l2_dbg_register *reg)
+{
+	u8 val;
+	int ret;
+
+	ret = ov5647_read(sd, reg->reg & 0xff, &val);
+	if (ret < 0)
+		return ret;
+
+	reg->val = val;
+	reg->size = 1;
+
+	return 0;
+}
+
+static int sensor_set_register(struct v4l2_subdev *sd,
+				const struct v4l2_dbg_register *reg)
+{
+	return ov5647_write(sd, reg->reg & 0xff, reg->val & 0xff);
+}
+#endif
+
+/**
+ * @short Subdev core operations registration
+ */
+static const struct v4l2_subdev_core_ops subdev_core_ops = {
+	.s_power		= sensor_power,
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register		= sensor_get_register,
+	.s_register		= sensor_set_register,
+#endif
+};
+
+static int s_stream(struct v4l2_subdev *sd, int enable)
+{
+	if (enable)
+		return ov5647_stream_on(sd);
+	else
+		return ov5647_stream_off(sd);
+}
+
+static const struct v4l2_subdev_video_ops subdev_video_ops = {
+	.s_stream =		s_stream,
+};
+
+static int enum_mbus_code(struct v4l2_subdev *sd,
+				struct v4l2_subdev_pad_config *cfg,
+				struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index > 0)
+		return -EINVAL;
+
+	code->code = MEDIA_BUS_FMT_SBGGR8_1X8;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops subdev_pad_ops = {
+	.enum_mbus_code =	enum_mbus_code,
+};
+
+/**
+ * @short Subdev operations registration
+ *
+ */
+static const struct v4l2_subdev_ops subdev_ops = {
+	.core		= &subdev_core_ops,
+	.video		= &subdev_video_ops,
+	.pad		= &subdev_pad_ops,
+};
+
+static int ov5647_detect(struct v4l2_subdev *sd)
+{
+	u8 read;
+	int ret;
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = ov5647_write(sd, OV5647_SW_RESET, 0x01);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_read(sd, OV5647_REG_CHIPID_H, &read);

drivers/media/i2c/ov5647.c line 484

Quoted 5 lines

drivers/media/i2c/ov5647.c new file +5 -0

+	if (ret < 0)
+		return ret;
+
+	if (read != 0x56) {
+		dev_err(&client->dev, "Wrong model version detected");

You might want to tell whether it's high or low ID register that fails the check. And possibly the bad value. Up to you.

Quoted 13 lines

drivers/media/i2c/ov5647.c new file +13 -0

+		return -ENODEV;
+	}
+
+	ret = ov5647_read(sd, OV5647_REG_CHIPID_L, &read);
+	if (ret < 0)
+		return ret;
+
+	if (read != 0x47) {
+		dev_err(&client->dev, "Wrong model version detected");
+		return -ENODEV;
+	}
+
+	return ov5647_write(sd, OV5647_SW_RESET, 0x00);

drivers/media/i2c/ov5647.c line 503

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+}
+
+static int ov5647_registered(struct v4l2_subdev *sd)
+{
+	return 0;
+}

The registered() callback is optional, i.e. you can drop an empty callback.

Quoted 135 lines

drivers/media/i2c/ov5647.c new file +135 -0

+
+static int ov5647_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	struct v4l2_mbus_framefmt *format =
+				v4l2_subdev_get_try_format(sd, fh->pad, 0);
+	struct v4l2_rect *crop =
+				v4l2_subdev_get_try_crop(sd, fh->pad, 0);
+
+	crop->left = OV5647_COLUMN_START_DEF;
+	crop->top = OV5647_ROW_START_DEF;
+	crop->width = OV5647_WINDOW_WIDTH_DEF;
+	crop->height = OV5647_WINDOW_HEIGHT_DEF;
+
+	format->code = MEDIA_BUS_FMT_SBGGR8_1X8;
+
+	format->width = OV5647_WINDOW_WIDTH_DEF;
+	format->height = OV5647_WINDOW_HEIGHT_DEF;
+	format->field = V4L2_FIELD_NONE;
+	format->colorspace = V4L2_COLORSPACE_SRGB;
+
+	return sensor_power(sd, true);
+}
+
+static int ov5647_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	return sensor_power(sd, false);
+}
+
+/**
+ * @short Subdev internal operations registration
+ *
+ */
+static const struct v4l2_subdev_internal_ops ov5647_subdev_internal_ops = {
+	.registered = ov5647_registered,
+	.open = ov5647_open,
+	.close = ov5647_close,
+};
+
+static int ov5647_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ov5647 *sensor;
+	int ret;
+	struct v4l2_subdev *sd;
+
+	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
+	if (sensor == NULL)
+		return -ENOMEM;
+
+	/* get system clock (xclk) */
+	sensor->xclk = devm_clk_get(dev, "xclk");
+	if (IS_ERR(sensor->xclk)) {
+		dev_err(dev, "could not get xclk");
+		return PTR_ERR(sensor->xclk);
+	}
+
+	sensor->xclk_freq = clk_get_rate(sensor->xclk);
+	if (sensor->xclk_freq != 25000000) {
+		dev_err(dev, "Unsupported clock frequency: %u\n",
+			sensor->xclk_freq);
+		return -EINVAL;
+	}
+
+	mutex_init(&sensor->lock);
+
+	sd = &sensor->sd;
+	v4l2_i2c_subdev_init(sd, client, &subdev_ops);
+	sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
+	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	ret = media_entity_pads_init(&sd->entity, 1, &sensor->pad);
+	if (ret < 0)
+		goto mutex_remove;
+
+	ret = ov5647_detect(sd);
+	if (ret < 0)
+		goto error;
+
+	ret = v4l2_async_register_subdev(sd);
+	if (ret < 0)
+		goto error;
+
+	dev_dbg(&client->dev, "OmniVision OV5647 camera driver probed\n");
+	return 0;
+error:
+	media_entity_cleanup(&sd->entity);
+mutex_remove:
+	mutex_destroy(&sensor->lock);
+	return ret;
+}
+
+static int ov5647_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov5647 *ov5647 = to_state(sd);
+
+	v4l2_async_unregister_subdev(&ov5647->sd);
+	media_entity_cleanup(&ov5647->sd.entity);
+	v4l2_device_unregister_subdev(sd);
+	mutex_destroy(&ov5647->lock);
+
+	return 0;
+}
+
+static const struct i2c_device_id ov5647_id[] = {
+	{ "ov5647", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ov5647_id);
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id ov5647_of_match[] = {
+	{ .compatible = "ovti,ov5647" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ov5647_of_match);
+#endif
+
+static struct i2c_driver ov5647_driver = {
+	.driver = {
+		.of_match_table = of_match_ptr(ov5647_of_match),
+		.name	= SENSOR_NAME,
+	},
+	.probe		= ov5647_probe,
+	.remove		= ov5647_remove,
+	.id_table	= ov5647_id,
+};
+
+module_i2c_driver(ov5647_driver);
+
+MODULE_AUTHOR("Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>");
+MODULE_DESCRIPTION("A low-level driver for OmniVision ov5647 sensors");
+MODULE_LICENSE("GPL v2");

Hi Sakari,

Thank you for your feedback.

The OV5647 sensor from Omnivision supports up to 2592x1944 @ 15 fps, RAW 8 and RAW 10 output formats, and MIPI CSI-2 interface.

The driver adds support for 640x480 RAW 8.

Signed-off-by Ramiro Oliveira <roliveir-HKixBCOQz3hWk0Htik3J/[email protected]>

---

+};

drivers/media/i2c/ov5647.c new file +18 -0

+
+	for (i = 0; i < array_size; i++) {
+		ret = ov5647_write(sd, regs[i].addr, regs[i].data);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
+{
+	u8 channel_id;
+	int ret;
+
+	ret = ov5647_read(sd, 0x4814, &channel_id);
+	if (ret < 0)
+		return ret;

drivers/media/i2c/ov5647.c new file +16 -0

+
+	return ov5647_write(sd, 0x300D, 0x01);
+}
+
+static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
+{
+	int ret;
+	u8 rdval;
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	if (standby)
+		rdval &= ~0x01;
+	else

drivers/media/i2c/ov5647.c new file +36 -0

+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	dev_dbg(&client->dev, "sensor init\n");
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_write_array(sd, ov5647_640x480,
+					ARRAY_SIZE(ov5647_640x480));
+	if (ret < 0) {
+		dev_err(&client->dev, "write sensor default regs error\n");
+		return ret;
+	}
+
+	ret = ov5647_set_virtual_channel(sd, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_read(sd, 0x0100, &resetval);
+	if (ret < 0)
+		return ret;
+
+	if (!(resetval & 0x01)) {
+		dev_err(&client->dev, "Device was in SW standby");
+		ret = ov5647_write(sd, 0x0100, 0x01);
+		if (ret < 0)
+			return ret;
+	}
+
+	return ov5647_write(sd, 0x4800, 0x04);
+}
+
+static int sensor_power(struct v4l2_subdev *sd, int on)
+{
+	int ret;

drivers/media/i2c/ov5647.c new file +15 -0

+		if (ret < 0) {
+			dev_err(&client->dev, "clk prepare enable failed\n");
+			goto out;
+		}
+
+		ret = ov5647_write_array(sd, sensor_oe_enable_regs,
+				ARRAY_SIZE(sensor_oe_enable_regs));
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"write sensor_oe_enable_regs error\n");
+			goto out;
+		}
+
+		ret = __sensor_init(sd);

drivers/media/i2c/ov5647.c new file +24 -0

+		ret = ov5647_write_array(sd, sensor_oe_disable_regs,
+				ARRAY_SIZE(sensor_oe_disable_regs));
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "disable oe failed\n");
+
+		ret = set_sw_standby(sd, true);
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "soft stby failed\n");
+
+		clk_disable_unprepare(ov5647->xclk);
+	}
+
+	/* Update the power count. */
+	ov5647->power_count += on ? 1 : -1;
+	WARN_ON(ov5647->power_count < 0);
+
+out:
+	mutex_unlock(&ov5647->lock);
+
+	return ret;
+}
+

drivers/media/i2c/ov5647.c new file +24 -0

+		dev_err(dev, "Unsupported clock frequency: %u\n",
+			sensor->xclk_freq);
+		return -EINVAL;
+	}
+
+	mutex_init(&sensor->lock);
+
+	sd = &sensor->sd;
+	v4l2_i2c_subdev_init(sd, client, &subdev_ops);
+	sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
+	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	ret = media_entity_pads_init(&sd->entity, 1, &sensor->pad);
+	if (ret < 0)
+		goto mutex_remove;
+
+	ret = ov5647_detect(sd);
+	if (ret < 0)
+		goto error;
+
+	ret = v4l2_async_register_subdev(sd);
+	if (ret < 0)
+		goto error;

Hi Ramiro,

please find some review comments below.

Quoted 7 lines · Ramiro Oliveira

The OV5647 sensor from Omnivision supports up to 2592x1944 @ 15 fps, RAW 8 and RAW 10 output formats, and MIPI CSI-2 interface.

The driver adds support for 640x480 RAW 8.

Signed-off-by Ramiro Oliveira <[email protected]>

---

[snip]

drivers/media/i2c/ov5647.c line 81

Quoted 12 lines

drivers/media/i2c/ov5647.c new file +12 -0

+
+struct ov5647 {
+	struct v4l2_subdev		sd;
+	struct media_pad		pad;
+	struct mutex			lock;
+	struct v4l2_mbus_framefmt	format;
+	unsigned int			width;
+	unsigned int			height;
+	int				power_count;
+	struct clk			*xclk;
+	/* External clock frequency currently supported is 30MHz */
+	u32				xclk_freq;

See a comment about 25MHz vs 30MHz below.

Also I assume you can remove 'xclk_freq' from the struct fields, it can be replaced by a local variable.

Quoted 1 line

+};

[snip]

drivers/media/i2c/ov5647.c line 214

Quoted 10 lines

drivers/media/i2c/ov5647.c new file +10 -0

+
+static int ov5647_read(struct v4l2_subdev *sd, u16 reg, u8 *val)
+{
+	int ret;
+	unsigned char data_w[2] = { reg >> 8, reg & 0xff };
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = i2c_master_send(client, data_w, 2);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",

s/i2c read error/i2c write error/

Quoted 5 lines

drivers/media/i2c/ov5647.c new file +5 -0

+			__func__, reg);
+		return ret;
+	}
+
+	ret = i2c_master_recv(client, val, 1);

drivers/media/i2c/ov5647.c line 225

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+	if (ret < 0)
+		dev_dbg(&client->dev, "%s: i2c read error, reg: %x\n",
+				__func__, reg);
+
+	return ret;
+

Please remove the empty line above.

drivers/media/i2c/ov5647.c line 231

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+}
+
+static int ov5647_write_array(struct v4l2_subdev *sd,
+				struct regval_list *regs, int array_size)
+{
+	int i = 0, ret;

Assignment of 'i' on declaration is not needed, please remove.

Quoted 22 lines

drivers/media/i2c/ov5647.c new file +22 -0

+
+	for (i = 0; i < array_size; i++) {
+		ret = ov5647_write(sd, regs[i].addr, regs[i].data);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
+{
+	u8 channel_id;
+	int ret;
+
+	ret = ov5647_read(sd, 0x4814, &channel_id);
+	if (ret < 0)
+		return ret;
+
+	channel_id &= ~(3 << 6);
+	return ov5647_write(sd, 0x4814, channel_id | (channel << 6));
+}

drivers/media/i2c/ov5647.c line 259

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+
+static int ov5647_stream_on(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ov5647_write(sd, 0x4202, 0x00);

Should you add a check of the returned value?

Review

Quoted 2 lines

(quoted diff) +2 -0

+
+	dev_dbg(&client->dev, "Stream on");

I would suggest to remove dev_dbg(), because ftrace will report to a user, when this function is called.

Also dev_dbg() in the middle of two I2C transfers in a row looks as being placed improperly.

drivers/media/i2c/ov5647.c line 270

Quoted 9 lines

drivers/media/i2c/ov5647.c new file +9 -0

+
+	return ov5647_write(sd, 0x300D, 0x00);
+}
+
+static int ov5647_stream_off(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ov5647_write(sd, 0x4202, 0x0f);

Should you add a check of the returned value?

Review

Quoted 2 lines

(quoted diff) +2 -0

+
+	dev_dbg(&client->dev, "Stream off");

I would suggest to remove dev_dbg(), because ftrace will report to a user, when this function is called.

Also dev_dbg() in the middle of two I2C transfers in a row looks as being placed improperly.

Quoted 20 lines

drivers/media/i2c/ov5647.c new file +20 -0

+
+	return ov5647_write(sd, 0x300D, 0x01);
+}
+
+static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
+{
+	int ret;
+	u8 rdval;
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	if (standby)
+		rdval &= ~0x01;
+	else
+		rdval |= 0x01;
+
+	return ov5647_write(sd, 0x0100, rdval);
+}

drivers/media/i2c/ov5647.c line 298

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+
+static int __sensor_init(struct v4l2_subdev *sd)
+{
+	int ret;
+	u8 resetval;
+	u8 rdval;

It could be possible to put declarations of 'resetval' and 'rdval' on the same line.

Quoted 36 lines

drivers/media/i2c/ov5647.c new file +36 -0

+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	dev_dbg(&client->dev, "sensor init\n");
+
+	ret = ov5647_read(sd, 0x0100, &rdval);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_write_array(sd, ov5647_640x480,
+					ARRAY_SIZE(ov5647_640x480));
+	if (ret < 0) {
+		dev_err(&client->dev, "write sensor default regs error\n");
+		return ret;
+	}
+
+	ret = ov5647_set_virtual_channel(sd, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = ov5647_read(sd, 0x0100, &resetval);
+	if (ret < 0)
+		return ret;
+
+	if (!(resetval & 0x01)) {
+		dev_err(&client->dev, "Device was in SW standby");
+		ret = ov5647_write(sd, 0x0100, 0x01);
+		if (ret < 0)
+			return ret;
+	}
+
+	return ov5647_write(sd, 0x4800, 0x04);
+}
+
+static int sensor_power(struct v4l2_subdev *sd, int on)
+{
+	int ret;

drivers/media/i2c/ov5647.c line 344

Quoted 10 lines

drivers/media/i2c/ov5647.c new file +10 -0

+	struct ov5647 *ov5647 = to_state(sd);
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	ret = 0;
+	mutex_lock(&ov5647->lock);
+
+	if (on && !ov5647->power_count)	{
+		dev_dbg(&client->dev, "OV5647 power on\n");
+
+		clk_set_rate(ov5647->xclk, ov5647->xclk_freq);

Now clk_set_rate() is redundant, please remove it.

If once it is needed again, please move it to the .probe function, so it is called only once in the runtime.

drivers/media/i2c/ov5647.c line 346

Quoted 2 lines

drivers/media/i2c/ov5647.c new file +2 -0

+
+		ret = clk_prepare_enable(ov5647->xclk);

I wonder would it be possible to unload the driver or to unbind the device and leave the clock unintentionally enabled? If yes, then this is a bug.

Quoted 19 lines

drivers/media/i2c/ov5647.c new file +19 -0

+		if (ret < 0) {
+			dev_err(&client->dev, "clk prepare enable failed\n");
+			goto out;
+		}
+
+		ret = ov5647_write_array(sd, sensor_oe_enable_regs,
+				ARRAY_SIZE(sensor_oe_enable_regs));
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"write sensor_oe_enable_regs error\n");
+			goto out;
+		}
+
+		ret = __sensor_init(sd);
+		if (ret < 0) {
+			clk_disable_unprepare(ov5647->xclk);
+			dev_err(&client->dev,
+				"Camera not available, check Power\n");

drivers/media/i2c/ov5647.c line 371

Quoted 6 lines

drivers/media/i2c/ov5647.c new file +6 -0

+			goto out;
+		}
+	} else if (!on && ov5647->power_count == 1) {
+		dev_dbg(&client->dev, "OV5647 power off\n");
+
+		dev_dbg(&client->dev, "disable oe\n");

One of two dev_dbg()'s above is apparently redundant.

Quoted 24 lines

drivers/media/i2c/ov5647.c new file +24 -0

+		ret = ov5647_write_array(sd, sensor_oe_disable_regs,
+				ARRAY_SIZE(sensor_oe_disable_regs));
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "disable oe failed\n");
+
+		ret = set_sw_standby(sd, true);
+
+		if (ret < 0)
+			dev_dbg(&client->dev, "soft stby failed\n");
+
+		clk_disable_unprepare(ov5647->xclk);
+	}
+
+	/* Update the power count. */
+	ov5647->power_count += on ? 1 : -1;
+	WARN_ON(ov5647->power_count < 0);
+
+out:
+	mutex_unlock(&ov5647->lock);
+
+	return ret;
+}
+

[snip]

drivers/media/i2c/ov5647.c line 551

Quoted 11 lines

drivers/media/i2c/ov5647.c new file +11 -0

+
+static int ov5647_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ov5647 *sensor;
+	int ret;
+	struct v4l2_subdev *sd;
+
+	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
+	if (sensor == NULL)

if (!sensor) is a bit shorter.

Quoted 5 lines

drivers/media/i2c/ov5647.c new file +5 -0

+		return -ENOMEM;
+
+	/* get system clock (xclk) */
+	sensor->xclk = devm_clk_get(dev, "xclk");
+	if (IS_ERR(sensor->xclk)) {