| Message ID | 1359652738-1544-2-git-send-email-s.nawrocki@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sylwester, Thanks for the patch. On Thursday 31 January 2013 18:18:57 Sylwester Nawrocki wrote: > From: Guennadi Liakhovetski <g.liakhovetski@gmx.de> > > This patch adds a document describing common OF bindings for video > capture, output and video processing devices. It is curently mainly > focused on video capture devices, with data busses defined by > standards like ITU-R BT.656 or MIPI-CSI2. > It also documents a method of describing data links between devices. > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> > Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> > --- > > Changes since v4: > - added note that multiple endpoints at a port can be active at any time, > - introduced optional 'ports' node aggregating 'port' nodes if required > to avoid conflicts with any child bus of a device, The 'ports' node seems to be missing from the documentation. > - improved definition of the 'slave-mode' property, > - corrected 'bus-width' and 'data-shift' properties specification, > - dropped 'immutable' properties in the example dts snippet. > --- > .../devicetree/bindings/media/video-interfaces.txt | 216 > ++++++++++++++++++++ 1 file changed, 216 insertions(+) > create mode 100644 > Documentation/devicetree/bindings/media/video-interfaces.txt > > diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt > b/Documentation/devicetree/bindings/media/video-interfaces.txt new file > mode 100644 > index 0000000..14c4be1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt > @@ -0,0 +1,216 @@ > +Common bindings for video data receiver and transmitter interfaces > + > +General concept > +--------------- > + > +Video data pipelines usually consist of external devices, e.g. camera > sensors, +controlled over an I2C, SPI or UART bus, and SoC internal IP > blocks, including +video DMA engines and video data processors. > + > +SoC internal blocks are described by DT nodes, placed similarly to other > SoC +blocks. External devices are represented as child nodes of their > respective +bus controller nodes, e.g. I2C. > + > +Data interfaces on all video devices are described by their child 'port' > nodes. +Configuration of a port depends on other devices participating in > the data +transfer and is described by 'endpoint' subnodes. > + > +device { > + #address-cells = <1>; > + #size-cells = <0>; > + port@0 { > + endpoint@0 { ... }; > + endpoint@1 { ... }; > + }; > + port@1 { ... }; > +}; > + > +If a port can be configured to work with more than one other device on the > same +bus, an 'endpoint' child node must be provided for each of them. If > more than +one port is present in a device node or there is more than one > endpoint at a +port, a common scheme, using '#address-cells', '#size-cells' > and 'reg' +properties is used. > + > +Two 'endpoint' nodes are linked with each other through their > 'remote-endpoint' +phandles. An endpoint subnode of a device contains all > properties needed for +configuration of this device for data exchange with > the other device. In most +cases properties at the peer 'endpoint' nodes > will be identical, however +they might need to be different when there is > any signal modifications on the +bus between two devices, e.g. there are > logic signal inverters on the lines. + > +It is allowed for multiple endpoints at a port to be active simultaneously, > +where supported by a device. For example in case where a data interface > of +a device is partitioned into multiple data busses, e.g. 16-bit input > port +divided into two separate ITU-R BT.656 8-bit busses. In such a case > bus-width +and data-shift properties can be used to assign physical data > lines to each +endpoint node (logical bus). > + > +Required properties > +------------------- > + > +If there is more than one 'port' or more than one 'endpoint' node or 'reg' > +property is present in port and/or endpoint nodes the following properties > +are required in relevant parent node: > + > + - #address-cells : number of cells required to define port/endpoint > + identifier, should be 1. > + - #size-cells : should be zero. > + > +Optional endpoint properties > +---------------------------- > + > +- remote-endpoint: phandle to an 'endpoint' subnode of the other device > node. +- slave-mode: a boolean property indicating that the link is run in > slave mode. + The default when this property is not specified is master > mode. In the slave + mode horizontal and vertical synchronization signals > are provided to the + slave device (data source) by the master device > (data sink). In the master + mode the data source device is also the > source of the synchronization signals. +- bus-width: number of data lines > actively used, valid for the parallel busses. +- data-shift: on the > parallel data busses, if bus-width is used to specify the + number of data > lines, data-shift can be used to specify which data lines are + used, e.g. > "bus-width=<8>; data-shift=<2>;" means, that lines 9:2 are used. +- > hsync-active: active state of HSYNC signal, 0/1 for LOW/HIGH respectively. > +- vsync-active: active state of VSYNC signal, 0/1 for LOW/HIGH > respectively. + Note, that if HSYNC and VSYNC polarities are not > specified, embedded + synchronization may be required, where supported. > +- data-active: similar to HSYNC and VSYNC, specifies data line polarity. > +- field-even-active: field signal level during the even field data > transmission. +- pclk-sample: sample data on rising (1) or falling (0) edge > of the pixel clock + signal. > +- data-lanes: an array of physical data lane indexes. Position of an entry > + determines the logical lane number, while the value of an entry indicates > + physical lane, e.g. for 2-lane MIPI CSI-2 bus we could have > + "data-lanes = <1 2>;", assuming the clock lane is on hardware lane 0. > + This property is valid for serial busses only (e.g. MIPI CSI-2). > +- clock-lanes: an array of physical clock lane indexes. Position of an > entry + determines the logical lane number, while the value of an entry > indicates + physical lane, e.g. for a MIPI CSI-2 bus we could have > "clock-lanes = <0>;", + which places the clock lane on hardware lane 0. > This property is valid for + serial busses only (e.g. MIPI CSI-2). Note > that for the MIPI CSI-2 bus this + array contains only one entry. > +- clock-noncontinuous: a boolean property to allow MIPI CSI-2 > non-continuous + clock mode. > + > +Example > +------- > + > +The example snippet below describes two data pipelines. ov772x and imx074 > are +camera sensors with a parallel and serial (MIPI CSI-2) video bus > respectively. +Both sensors are on the I2C control bus corresponding to the > i2c0 controller +node. ov772x sensor is linked directly to the ceu0 video > host interface. +imx074 is linked to ceu0 through the MIPI CSI-2 receiver > (csi2). ceu0 has a +(single) DMA engine writing captured data to memory. > ceu0 node has a single +'port' node which may indicate that at any time > only one of the following data +pipelines can be active: ov772x -> ceu0 or > imx074 -> csi2 -> ceu0. + > + ceu0: ceu@0xfe910000 { > + compatible = "renesas,sh-mobile-ceu"; > + reg = <0xfe910000 0xa0>; > + interrupts = <0x880>; > + > + mclk: master_clock { > + compatible = "renesas,ceu-clock"; > + #clock-cells = <1>; > + clock-frequency = <50000000>; /* Max clock frequency */ > + clock-output-names = "mclk"; > + }; > + > + port { > + #address-cells = <1>; > + #size-cells = <0>; > + > + /* Parallel bus endpoint */ > + ceu0_1: endpoint@1 { > + reg = <1>; /* Local endpoint # */ > + remote = <&ov772x_1_1>; /* Remote phandle */ > + bus-width = <8>; /* Used data lines */ > + data-shift = <2>; /* Lines 9:2 are used */ > + > + /* If hsync-active/vsync-active are missing, > + embedded BT.656 sync is used */ > + hsync-active = <0>; /* Active low */ > + vsync-active = <0>; /* Active low */ > + data-active = <1>; /* Active high */ > + pclk-sample = <1>; /* Rising */ > + }; > + > + /* MIPI CSI-2 bus endpoint */ > + ceu0_0: endpoint@0 { > + reg = <0>; > + remote = <&csi2_2>; > + }; > + }; > + }; > + > + i2c0: i2c@0xfff20000 { > + ... > + ov772x_1: camera@0x21 { > + compatible = "omnivision,ov772x"; > + reg = <0x21>; > + vddio-supply = <®ulator1>; > + vddcore-supply = <®ulator2>; > + > + clock-frequency = <20000000>; > + clocks = <&mclk 0>; > + clock-names = "xclk"; > + > + port { > + /* With 1 endpoint per port no need for addresses. */ > + ov772x_1_1: endpoint { > + bus-width = <8>; > + remote-endpoint = <&ceu0_1>; > + hsync-active = <1>; > + vsync-active = <0>; /* Who came up with an > + inverter here ?... */ > + data-active = <1>; > + pclk-sample = <1>; > + }; > + }; > + }; > + > + imx074: camera@0x1a { > + compatible = "sony,imx074"; > + reg = <0x1a>; > + vddio-supply = <®ulator1>; > + vddcore-supply = <®ulator2>; > + > + clock-frequency = <30000000>; /* Shared clock with ov772x_1 */ > + clocks = <&mclk 0>; > + clock-names = "sysclk"; /* Assuming this is the > + name in the datasheet */ > + port { > + imx074_1: endpoint { > + clock-lanes = <0>; > + data-lanes = <1 2>; > + remote-endpoint = <&csi2_1>; > + }; > + }; > + }; > + }; > + > + csi2: csi2@0xffc90000 { > + compatible = "renesas,sh-mobile-csi2"; > + reg = <0xffc90000 0x1000>; > + interrupts = <0x17a0>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + port@1 { > + compatible = "renesas,csi2c"; /* One of CSI2I and CSI2C. */ > + reg = <1>; /* CSI-2 PHY #1 of 2: PHY_S, > + PHY_M has port address 0, > + is unused. */ > + csi2_1: endpoint { > + clock-lanes = <0>; > + data-lanes = <2 1>; > + remote-endpoint = <&imx074_1>; > + }; > + }; > + port@2 { > + reg = <2>; /* port 2: link to the CEU */ > + > + csi2_2: endpoint { > + remote-endpoint = <&ceu0_0>; > + }; > + }; > + };
Hi Laurent, On 01/31/2013 06:33 PM, Laurent Pinchart wrote: >> Changes since v4: >> - added note that multiple endpoints at a port can be active at any time, >> - introduced optional 'ports' node aggregating 'port' nodes if required >> to avoid conflicts with any child bus of a device, > > The 'ports' node seems to be missing from the documentation. Ouch, indeed. I must have lost it somewhere during rebase :-/ I'll re-create it and resend. -- Regards, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt new file mode 100644 index 0000000..14c4be1 --- /dev/null +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt @@ -0,0 +1,216 @@ +Common bindings for video data receiver and transmitter interfaces + +General concept +--------------- + +Video data pipelines usually consist of external devices, e.g. camera sensors, +controlled over an I2C, SPI or UART bus, and SoC internal IP blocks, including +video DMA engines and video data processors. + +SoC internal blocks are described by DT nodes, placed similarly to other SoC +blocks. External devices are represented as child nodes of their respective +bus controller nodes, e.g. I2C. + +Data interfaces on all video devices are described by their child 'port' nodes. +Configuration of a port depends on other devices participating in the data +transfer and is described by 'endpoint' subnodes. + +device { + #address-cells = <1>; + #size-cells = <0>; + port@0 { + endpoint@0 { ... }; + endpoint@1 { ... }; + }; + port@1 { ... }; +}; + +If a port can be configured to work with more than one other device on the same +bus, an 'endpoint' child node must be provided for each of them. If more than +one port is present in a device node or there is more than one endpoint at a +port, a common scheme, using '#address-cells', '#size-cells' and 'reg' +properties is used. + +Two 'endpoint' nodes are linked with each other through their 'remote-endpoint' +phandles. An endpoint subnode of a device contains all properties needed for +configuration of this device for data exchange with the other device. In most +cases properties at the peer 'endpoint' nodes will be identical, however +they might need to be different when there is any signal modifications on the +bus between two devices, e.g. there are logic signal inverters on the lines. + +It is allowed for multiple endpoints at a port to be active simultaneously, +where supported by a device. For example in case where a data interface of +a device is partitioned into multiple data busses, e.g. 16-bit input port +divided into two separate ITU-R BT.656 8-bit busses. In such a case bus-width +and data-shift properties can be used to assign physical data lines to each +endpoint node (logical bus). + +Required properties +------------------- + +If there is more than one 'port' or more than one 'endpoint' node or 'reg' +property is present in port and/or endpoint nodes the following properties +are required in relevant parent node: + + - #address-cells : number of cells required to define port/endpoint + identifier, should be 1. + - #size-cells : should be zero. + +Optional endpoint properties +---------------------------- + +- remote-endpoint: phandle to an 'endpoint' subnode of the other device node. +- slave-mode: a boolean property indicating that the link is run in slave mode. + The default when this property is not specified is master mode. In the slave + mode horizontal and vertical synchronization signals are provided to the + slave device (data source) by the master device (data sink). In the master + mode the data source device is also the source of the synchronization signals. +- bus-width: number of data lines actively used, valid for the parallel busses. +- data-shift: on the parallel data busses, if bus-width is used to specify the + number of data lines, data-shift can be used to specify which data lines are + used, e.g. "bus-width=<8>; data-shift=<2>;" means, that lines 9:2 are used. +- hsync-active: active state of HSYNC signal, 0/1 for LOW/HIGH respectively. +- vsync-active: active state of VSYNC signal, 0/1 for LOW/HIGH respectively. + Note, that if HSYNC and VSYNC polarities are not specified, embedded + synchronization may be required, where supported. +- data-active: similar to HSYNC and VSYNC, specifies data line polarity. +- field-even-active: field signal level during the even field data transmission. +- pclk-sample: sample data on rising (1) or falling (0) edge of the pixel clock + signal. +- data-lanes: an array of physical data lane indexes. Position of an entry + determines the logical lane number, while the value of an entry indicates + physical lane, e.g. for 2-lane MIPI CSI-2 bus we could have + "data-lanes = <1 2>;", assuming the clock lane is on hardware lane 0. + This property is valid for serial busses only (e.g. MIPI CSI-2). +- clock-lanes: an array of physical clock lane indexes. Position of an entry + determines the logical lane number, while the value of an entry indicates + physical lane, e.g. for a MIPI CSI-2 bus we could have "clock-lanes = <0>;", + which places the clock lane on hardware lane 0. This property is valid for + serial busses only (e.g. MIPI CSI-2). Note that for the MIPI CSI-2 bus this + array contains only one entry. +- clock-noncontinuous: a boolean property to allow MIPI CSI-2 non-continuous + clock mode. + +Example +------- + +The example snippet below describes two data pipelines. ov772x and imx074 are +camera sensors with a parallel and serial (MIPI CSI-2) video bus respectively. +Both sensors are on the I2C control bus corresponding to the i2c0 controller +node. ov772x sensor is linked directly to the ceu0 video host interface. +imx074 is linked to ceu0 through the MIPI CSI-2 receiver (csi2). ceu0 has a +(single) DMA engine writing captured data to memory. ceu0 node has a single +'port' node which may indicate that at any time only one of the following data +pipelines can be active: ov772x -> ceu0 or imx074 -> csi2 -> ceu0. + + ceu0: ceu@0xfe910000 { + compatible = "renesas,sh-mobile-ceu"; + reg = <0xfe910000 0xa0>; + interrupts = <0x880>; + + mclk: master_clock { + compatible = "renesas,ceu-clock"; + #clock-cells = <1>; + clock-frequency = <50000000>; /* Max clock frequency */ + clock-output-names = "mclk"; + }; + + port { + #address-cells = <1>; + #size-cells = <0>; + + /* Parallel bus endpoint */ + ceu0_1: endpoint@1 { + reg = <1>; /* Local endpoint # */ + remote = <&ov772x_1_1>; /* Remote phandle */ + bus-width = <8>; /* Used data lines */ + data-shift = <2>; /* Lines 9:2 are used */ + + /* If hsync-active/vsync-active are missing, + embedded BT.656 sync is used */ + hsync-active = <0>; /* Active low */ + vsync-active = <0>; /* Active low */ + data-active = <1>; /* Active high */ + pclk-sample = <1>; /* Rising */ + }; + + /* MIPI CSI-2 bus endpoint */ + ceu0_0: endpoint@0 { + reg = <0>; + remote = <&csi2_2>; + }; + }; + }; + + i2c0: i2c@0xfff20000 { + ... + ov772x_1: camera@0x21 { + compatible = "omnivision,ov772x"; + reg = <0x21>; + vddio-supply = <®ulator1>; + vddcore-supply = <®ulator2>; + + clock-frequency = <20000000>; + clocks = <&mclk 0>; + clock-names = "xclk"; + + port { + /* With 1 endpoint per port no need for addresses. */ + ov772x_1_1: endpoint { + bus-width = <8>; + remote-endpoint = <&ceu0_1>; + hsync-active = <1>; + vsync-active = <0>; /* Who came up with an + inverter here ?... */ + data-active = <1>; + pclk-sample = <1>; + }; + }; + }; + + imx074: camera@0x1a { + compatible = "sony,imx074"; + reg = <0x1a>; + vddio-supply = <®ulator1>; + vddcore-supply = <®ulator2>; + + clock-frequency = <30000000>; /* Shared clock with ov772x_1 */ + clocks = <&mclk 0>; + clock-names = "sysclk"; /* Assuming this is the + name in the datasheet */ + port { + imx074_1: endpoint { + clock-lanes = <0>; + data-lanes = <1 2>; + remote-endpoint = <&csi2_1>; + }; + }; + }; + }; + + csi2: csi2@0xffc90000 { + compatible = "renesas,sh-mobile-csi2"; + reg = <0xffc90000 0x1000>; + interrupts = <0x17a0>; + #address-cells = <1>; + #size-cells = <0>; + + port@1 { + compatible = "renesas,csi2c"; /* One of CSI2I and CSI2C. */ + reg = <1>; /* CSI-2 PHY #1 of 2: PHY_S, + PHY_M has port address 0, + is unused. */ + csi2_1: endpoint { + clock-lanes = <0>; + data-lanes = <2 1>; + remote-endpoint = <&imx074_1>; + }; + }; + port@2 { + reg = <2>; /* port 2: link to the CEU */ + + csi2_2: endpoint { + remote-endpoint = <&ceu0_0>; + }; + }; + };