Hi Eugen, On Tue, Nov 17, 2020 at 11:14:18AM +0000, Eugen.Hristev@xxxxxxxxxxxxx wrote: > On 17.11.2020 12:37, Jacopo Mondi wrote: > > Hi again, > > > > On Thu, Nov 12, 2020 at 03:34:35PM +0200, Eugen Hristev wrote: > >> Add bindings documentation for Microchip CSI2 Demultiplexer controller. > >> > >> CSI2DC is a demultiplexer from Synopsys IDI interface specification to > >> parallel interface connection or direct memory access. > >> > >> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> > >> --- > >> Changes in v5: > >> - modified bindings as per Rob Herring review > >> > >> Changes in v4: > >> - Removed property for inter-line-delay and for clock continuous/non-continuous > >> - Removed virtual channel by reg for second endpoint > >> > >> Changes in v3: > >> - Removed some text from description, as it was explained in the schema > >> - fixed other things as per Rob's review > >> - moved some text inside the schema, like the clock description > >> > >> Changes in v2: > >> - fixed warnings reported by dt_binding_check > >> > >> .../bindings/media/microchip,csi2dc.yaml | 119 ++++++++++++++++++ > >> 1 file changed, 119 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/media/microchip,csi2dc.yaml > >> > >> diff --git a/Documentation/devicetree/bindings/media/microchip,csi2dc.yaml b/Documentation/devicetree/bindings/media/microchip,csi2dc.yaml > >> new file mode 100644 > >> index 000000000000..e79f0d6ba9db > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/media/microchip,csi2dc.yaml > >> @@ -0,0 +1,119 @@ > >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >> +%YAML 1.2 > >> +--- > >> +$id: http://devicetree.org/schemas/media/microchip,csi2dc.yaml# > >> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >> + > >> +title: Microchip CSI2 Demux Controller (CSI2DC) > >> + > >> +maintainers: > >> + - Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> > >> + > >> +description: > >> + CSI2DC - Camera Serial Interface 2 Demux Controller > >> + > >> + CSI2DC is a hardware block that receives incoming data from an IDI interface > >> + and filters packets based on their data type and virtual channel identifier, > >> + then converts the byte stream into a cross clock domain to a pixel stream > >> + to a parallel interface that can be read by a sensor controller. > >> + > >> + CSI2DC provides two pipes, one video pipe and one data pipe. Video pipe > >> + is connected to a sensor controller and the data pipe is accessible > >> + as a DMA slave port to a DMA controller. > >> + > >> + CSI2DC supports a single 'port' node as a source pad with Synopsys 32-bit > >> + IDI interface. The connected endpoint must be a IDI interface compatible > >> + device (like Synopsys CSI2HOST) , that can provide 32-bit IDI interface > >> + connection as sink pad. > >> + For media entity and endpoints please refer to the bindings defined in > >> + Documentation/devicetree/bindings/media/video-interfaces.txt. > >> + For Synopsys IDI interface please refer to > >> + Documentation/devicetree/bindings/media/snps,dw-csi-plat.txt > > > > Is it me or this file doesn't exists on the most recent media/master > > and on v5.10-rc4 ? > > Hi Jacopo, > > Thanks for reviewing this patch. > You are right. As I said at some point during the review, actually this > controller has an input the IDI interface which is not currently in > kernel. There is a patch series that adds the Synopsys platform driver, > but nobody worked on it anymore and I use it for testing my driver. > You can see the last version that was sent here: > > https://patchwork.linuxtv.org/project/linux-media/patch/1560280855-18085-2-git-send-email-luis.oliveira@xxxxxxxxxxxx/ > > > I sent this series to understand how to improve and how to get my driver > in kernel, but indeed there are holes, especially this input type of bus > which is not in the subsystem either. > > So how would you suggest to move forward ? Remove the reference to the > synopsys binding and just leave 'IDI interface' which is undocumented ? mmm, I see... I was hoping it was a simple CSI-2 tx :) The Synopsys proposed bindings do not tell much as they don't describe the csi2host output port. I would just mention "Synopsys IDI compatible interface" without mentioning a file that cannot be accessed :) Thanks j > > Eugen > > > > >> + > >> + CSI2DC supports one 'port' node as sink pad with parallel interface. This is > >> + called video pipe. > >> + This port has an 'endpoint' can then be used as a source pad for another > >> + controller (next in pipeline). > >> + Please refer to the bindings defined in > >> + Documentation/devicetree/bindings/media/video-interfaces.txt. > >> + > >> + CSI2DC also supports direct access to the data through AHB, via DMA channel, > >> + called data pipe. > >> + Because of this, the sink 'port' child node (second) is not mandatory. > >> + If the sink 'port' child node is missing, only data pipe is available. > >> + > >> +properties: > >> + compatible: > >> + const: microchip,sama7g5-csi2dc > >> + > >> + reg: > >> + maxItems: 1 > >> + > >> + clocks: > >> + maxItems: 2 > >> + > >> + clock-names: > >> + description: > >> + CSI2DC must have two clocks to function correctly. One clock is the > >> + peripheral clock for the inside functionality of the hardware block. > >> + This is named 'pclk'. The second clock must be the cross domain clock, > >> + in which CSI2DC will perform clock crossing. This clock must be fed > >> + by the next controller in pipeline, which usually is a sensor controller. > >> + Normally this clock should be given by this sensor controller who > >> + is also a clock source. This clock is named 'scck', sensor controller clock. > >> + items: > >> + - const: pclk > >> + - const: scck > >> + > >> + ports: > >> + type: object > >> + description: > >> + List of ports > >> + > >> + properties: > >> + port@0: > >> + type: object > >> + description: > >> + Input port node, single endpoint describing the input pad. > >> + port@1: > >> + type: object > >> + description: > >> + Output port node, single endpoint, describing the output pad. > >> + > >> +additionalProperties: false > >> + > >> +required: > >> + - compatible > >> + - reg > >> + - clocks > >> + - clock-names > >> + - ports > >> + > >> +examples: > >> + - | > >> + csi2dc@e1404000 { > >> + compatible = "microchip,sama7g5-csi2dc"; > >> + reg = <0xe1404000 0x500>; > >> + clocks = <&pclk>, <&scck>; > >> + clock-names = "pclk", "scck"; > >> + > >> + ports { > >> + #address-cells = <1>; > >> + #size-cells = <0>; > >> + port@0 { > >> + reg = <0>; /* must be 0, first child port */ > >> + csi2dc_in: endpoint { /* input from IDI interface */ > >> + remote-endpoint = <&csi2host_out>; > >> + }; > >> + }; > >> + > >> + port@1 { > >> + reg = <1>; /* must be 1, second child port */ > >> + csi2dc_out: endpoint { > >> + remote-endpoint = <&xisc_in>; /* output to sensor controller */ > >> + }; > >> + }; > >> + }; > >> + }; > >> + > >> +... > >> -- > >> 2.25.1 > >> >
