On 06/23/2017 12:25 PM, H. Nikolaus Schaller wrote: > Hi Hugues, > >> Am 22.06.2017 um 17:05 schrieb Hugues Fruchet <hugues.fruchet@xxxxxx>: >> >> From: "H. Nikolaus Schaller" <hns@xxxxxxxxxxxxx> >> >> This adds documentation of device tree bindings >> for the OV965X family camera sensor module. >> >> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> >> Signed-off-by: Hugues Fruchet <hugues.fruchet@xxxxxx> >> --- >> .../devicetree/bindings/media/i2c/ov965x.txt | 37 ++++++++++++++++++++++ >> 1 file changed, 37 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/media/i2c/ov965x.txt >> >> diff --git a/Documentation/devicetree/bindings/media/i2c/ov965x.txt b/Documentation/devicetree/bindings/media/i2c/ov965x.txt >> new file mode 100644 >> index 0000000..0e0de1f >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/media/i2c/ov965x.txt >> @@ -0,0 +1,37 @@ >> +* Omnivision OV9650/9652/9655 CMOS sensor >> + >> +The Omnivision OV965x sensor support multiple resolutions output, such as >> +CIF, SVGA, UXGA. It also can support YUV422/420, RGB565/555 or raw RGB >> +output format. >> + >> +Required Properties: >> +- compatible: should be one of >> + "ovti,ov9650" >> + "ovti,ov9652" >> + "ovti,ov9655" >> +- clocks: reference to the mclk input clock. > > I wonder why you have removed the clock-frequency property? > > In some situations the camera driver must be able to tell the clock source > which frequency it wants to see. > > For example we connect the camera to an OMAP3-ISP (image signal processor) and > there it is assumed that camera modules know the frequency and set the clock, e.g.: > > http://elixir.free-electrons.com/linux/v4.4/source/Documentation/devicetree/bindings/media/i2c/nokia,smia.txt#L52 > http://elixir.free-electrons.com/linux/v3.14/source/Documentation/devicetree/bindings/media/i2c/mt9p031.txt > > If your clock is constant and defined elsewhere we should make this > property optional instead of required. But it should not be missing. > > Here is a hack to get it into your code: > > http://git.goldelico.com/?p=gta04-kernel.git;a=blobdiff;f=drivers/media/i2c/ov9650.c;h=b7ab46c775b9e40087e427ae0777e9f7c283694a;hp=1846bcbb19ae71ce686dade320aa06ce2e429ca4;hb=ca85196f6fd9a77e5a0f796aeaf7aa2cde60ce91;hpb=8a71f21b75543a6d99102be1ae4677b28c478ac9 > Here is how it is used on my DT, the camera clock is a fixed crystal 24M clock: + clocks { + clk_ext_camera: clk-ext-camera { + #clock-cells = <0>; + compatible = "fixed-clock"; + clock-frequency = <24000000>; + }; + }; [...] + ov9655: camera@30 { + compatible = "ovti,ov9655"; + reg = <0x30>; + pwdn-gpios = <&gpioh 13 GPIO_ACTIVE_HIGH>; + clocks = <&clk_ext_camera>; + status = "okay"; + + port { + ov9655_0: endpoint { + remote-endpoint = <&dcmi_0>; + }; + }; + }; >> + >> +Optional Properties: >> +- resetb-gpios: reference to the GPIO connected to the resetb pin, if any. >> +- pwdn-gpios: reference to the GPIO connected to the pwdn pin, if any. > > Here I wonder why you did split that up into two gpios. Each "*-gpios" can have > multiple entries and if one is not used, a 0 can be specified to make it being ignored. > > But it is up to DT maintainers what they prefer: separate single gpios or a single gpio array. I have followed the ov2640 binding, which have the same pins naming (resetb/pwdn). As far as I see, separate single gpios are commonly used in Documentation/devicetree/bindings/media/i2c/ > > > What I am missing to support the GTA04 camera is the control of the optional "vana-supply". > So the driver does not power up the camera module when needed and therefore probing fails. > > - vana-supply: a regulator to power up the camera module. > > Driver code is not complex to add: > > http://git.goldelico.com/?p=gta04-kernel.git;a=blobdiff;f=drivers/media/i2c/ov9650.c;h=1846bcbb19ae71ce686dade320aa06ce2e429ca4;hp=c0819afdcefcb19da351741d51dad00aaf909254;hb=8a71f21b75543a6d99102be1ae4677b28c478ac9;hpb=6db55fc472eea2ec6db03833df027aecf6649f88 Yes, I saw it in your code, but as I don't have any programmable power supply on my setup, I have not pushed this commit. And I also don't have a clock to enable/disable -fixed clock-, I need to check the behaviour when disabling/enabling a fixed clock, I will give it a try. > >> + >> +The device node must contain one 'port' child node for its digital output >> +video port, in accordance with the video interface bindings defined in >> +Documentation/devicetree/bindings/media/video-interfaces.txt. >> + >> +Example: >> + >> +&i2c2 { >> + ov9655: camera@30 { >> + compatible = "ovti,ov9655"; >> + reg = <0x30>; >> + pwdn-gpios = <&gpioh 13 GPIO_ACTIVE_HIGH>; >> + clocks = <&clk_ext_camera>; >> + >> + port { >> + ov9655: endpoint { >> + remote-endpoint = <&dcmi_0>; >> + }; >> + }; >> + }; >> +}; >> -- >> 1.9.1 >> > > BR and thanks, > Nikolaus >
