On Tue, Dec 17, 2019 at 4:15 AM Tomasz Figa <tfiga@xxxxxxxxxxxx> wrote: > > Hi Rob, Dongchun, > > On Wed, Dec 11, 2019 at 8:29 PM Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx> wrote: > > > > Add DT bindings documentation for Omnivision OV02A10 image sensor. > > > > Reviewed-by: Rob Herring <robh@xxxxxxxxxx> > > Signed-off-by: Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx> > > --- > > .../devicetree/bindings/media/i2c/ov02a10.txt | 54 ++++++++++++++++++++++ > > MAINTAINERS | 7 +++ > > 2 files changed, 61 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/media/i2c/ov02a10.txt > > > > diff --git a/Documentation/devicetree/bindings/media/i2c/ov02a10.txt b/Documentation/devicetree/bindings/media/i2c/ov02a10.txt > > new file mode 100644 > > index 0000000..18acc4f > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/media/i2c/ov02a10.txt > > @@ -0,0 +1,54 @@ > > +* Omnivision OV02A10 MIPI CSI-2 sensor > > + > > +Required Properties: > > +- compatible: shall be "ovti,ov02a10" > > +- clocks: reference to the eclk input clock > > +- clock-names: shall be "eclk" > > +- dovdd-supply: Digital I/O voltage supply, 1.8 volts > > +- avdd-supply: Analog voltage supply, 2.8 volts > > +- dvdd-supply: Digital core voltage supply, 1.8 volts > > +- powerdown-gpios: reference to the GPIO connected to the powerdown pin, > > + if any. This is an active low signal to the OV02A10. > > On the hardware level this pin is active high, i.e. the device is > powered down when the signal is high. > > > +- reset-gpios: reference to the GPIO connected to the reset pin, if any. > > + This is an active high signal to the OV02A10. > > On the hardware level this pin is active low, i.e. the device is held > in reset when the signal is low. > > However, there is some confusion around how the polarity flag in the > GPIO specifier is supposed to be used. > > As per [1], > > "The gpio-specifier's polarity flag should represent the physical > level at the GPIO controller that achieves (or represents, for inputs) > a logically asserted value at the device. The exact definition of > logically asserted should be defined by the binding for the device." > > In this case it sounds like "logically asserted" means the device is > powered down or held in reset, respectively, which would suggest that > the specifiers should have GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW > respectively. The latter would cause the GPIO subsystem to invert the > values set by the consumers, which would then be confusing from the > driver implementation point of view. > > Should the pin be renamed to "nreset"? It would change the meaning of > "logically asserted" to "device is not held in reset" and so > GPIO_ACTIVE_HIGH (or 0) would be the right value to use. > > [1] https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/gpio/gpio.txt#L83 + Bartosz, Linus, Sakari and the linux-gpio ML for a broader audience. Would appreciate some feedback on what's the proper way of defining GPIO polarity. Thanks! Best regards, Tomasz > > Best regards, > Tomasz > > > + > > +Optional Properties: > > +- rotation: as defined in > > + Documentation/devicetree/bindings/media/video-interfaces.txt, > > + valid values are 0 (sensor mounted upright) and 180 (sensor > > + mounted upside down). > > + > > +The device node shall contain one 'port' child node with an > > +'endpoint' subnode for its digital output video port, > > +in accordance with the video interface bindings defined in > > +Documentation/devicetree/bindings/media/video-interfaces.txt. > > + > > +Example: > > +&i2c4 { > > + ov02a10: camera-sensor@3d { > > + compatible = "ovti,ov02a10"; > > + reg = <0x3d>; > > + pinctrl-names = "default"; > > + pinctrl-0 = <&camera_pins_cam1_mclk_on>; > > + > > + clocks = <&topckgen CLK_TOP_MUX_CAMTG2>, > > + <&topckgen CLK_TOP_UNIVP_192M_D8>; > > + clock-names = "eclk", "freq_mux"; > > + clock-frequency = <24000000>; > > + > > + dovdd-supply = <&mt6358_vcamio_reg>; > > + avdd-supply = <&mt6358_vcama1_reg>; > > + dvdd-supply = <&mt6358_vcn18_reg>; > > + powerdown-gpios = <&pio 107 GPIO_ACTIVE_LOW>; > > + reset-gpios = <&pio 109 GPIO_ACTIVE_HIGH>; > > + rotation = <180>; > > + > > + port { > > + /* MIPI CSI-2 bus endpoint */ > > + ov02a10_core: endpoint { > > + remote-endpoint = <&ov02a10_0>; > > + link-frequencies = /bits/ 64 <390000000>; > > + }; > > + }; > > + }; > > +}; > > diff --git a/MAINTAINERS b/MAINTAINERS > > index bd5847e..92a868c 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -12130,6 +12130,13 @@ T: git git://linuxtv.org/media_tree.git > > S: Maintained > > F: drivers/media/i2c/ov13858.c > > > > +OMNIVISION OV02A10 SENSOR DRIVER > > +M: Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx> > > +L: linux-media@xxxxxxxxxxxxxxx > > +T: git git://linuxtv.org/media_tree.git > > +S: Maintained > > +F: Documentation/devicetree/bindings/media/i2c/ov02a10.txt > > + > > OMNIVISION OV2680 SENSOR DRIVER > > M: Rui Miguel Silva <rmfrfs@xxxxxxxxx> > > L: linux-media@xxxxxxxxxxxxxxx > > -- > > 2.9.2
