Re: [PATCH 2/4] drm: Add DT bindings documentation for ARC PGU display controller

[Alexey Brodkin]

Hi Rob,

On Tue, 2016-02-23 at 14:38 -0600, Rob Herring wrote:
+AD4- On Fri, Feb 19, 2016 at 04:03:52PM +-0300, Alexey Brodkin wrote:
+AD4- +AD4- 
+AD4- +AD4- This add DT bindings documentation for ARC PGU display controller.
+AD4- +AD4- 
+AD4- +AD4- Signed-off-by: Alexey Brodkin +ADw-abrodkin+AEA-synopsys.com+AD4-
+AD4- +AD4- Cc: Rob Herring +ADw-robh+-dt+AEA-kernel.org+AD4-
+AD4- +AD4- Cc: Pawel Moll +ADw-pawel.moll+AEA-arm.com+AD4-
+AD4- +AD4- Cc: Mark Rutland +ADw-mark.rutland+AEA-arm.com+AD4-
+AD4- +AD4- Cc: Ian Campbell +ADw-ijc+-devicetree+AEA-hellion.org.uk+AD4-
+AD4- +AD4- Cc: Kumar Gala +ADw-galak+AEA-codeaurora.org+AD4-
+AD4- +AD4- Cc: devicetree+AEA-vger.kernel.org
+AD4- +AD4- Cc: linux-snps-arc+AEA-lists.infradead.org
+AD4- +AD4- ---
+AD4- +AD4- +AKA-.../devicetree/bindings/display/snps,arcpgu.txt+AKAAoACgAKAAfA- 74 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
+AD4- +AD4- +AKA-1 file changed, 74 insertions(+-)
+AD4- +AD4- +AKA-create mode 100644 Documentation/devicetree/bindings/display/snps,arcpgu.txt
+AD4- +AD4- 
+AD4- +AD4- diff --git a/Documentation/devicetree/bindings/display/snps,arcpgu.txt
+AD4- +AD4- b/Documentation/devicetree/bindings/display/snps,arcpgu.txt
+AD4- +AD4- new file mode 100644
+AD4- +AD4- index 0000000..c8382fb
+AD4- +AD4- --- /dev/null
+AD4- +AD4- +-+-+- b/Documentation/devicetree/bindings/display/snps,arcpgu.txt
+AD4- +AD4- +AEAAQA- -0,0 +-1,74 +AEAAQA-
+AD4- +AD4- +-ARC PGU
+AD4- +AD4- +-
+AD4- +AD4- +-This is a display controller found on several development boards produced
+AD4- +AD4- +-by Synopsys. The ARC PGU is an RGB streamer that reads the data from a
+AD4- +AD4- +-framebuffer and sends it to a single digital encoder (usually HDMI).
+AD4- +AD4- +-
+AD4- +AD4- +-Required properties:
+AD4- +AD4- +-+AKAAoA-- compatible: +ACI-snps,arcpgu+ACI-
+AD4- Seems like this should be more specific. Is there some sort or+AKA-
+AD4- versioning with ARC blocks?

Well as of today there's only one and only version of PGU.
So is there a real need for +ACI-snps,arcpgu-1.0+ACI-?

+AD4- +AD4- 
+AD4- +AD4- +-+AKAAoA-- reg: Physical base address and length of the controller's registers.
+AD4- +AD4- +-+AKAAoA-- clocks: A list of phandle +- clock-specifier pairs, one for each
+AD4- +AD4- +-+AKAAoACgAKA-entry in 'clock-names'.
+AD4- +AD4- +-+AKAAoA-- clock-names: A list of clock names. For ARC PGU it should contain:
+AD4- +AD4- +-+AKAAoACgAKAAoACg-- +ACI-pxlclk+ACI- for the clock feeding the output PLL of the controller.
+AD4- +AD4- +-+AKAAoA-- encoder-slave: Phandle of encoder chip.
+AD4- This is unnecessary with the OF graph.

Do you mean I may drop +ACI-encoder-slave+ACI- from bindings description?
I actually thought about that because in case of simulation platform where
this device is also used there's no encoder as well as no connector - we're
dealing with memory area which is read by host and then displayed on host's
display.

+AD4- +AD4- +-
+AD4- +AD4- +-/ +AHs-
+AD4- +AD4- +-	...
+AD4- +AD4- +-
+AD4- +AD4- +-	pgu+AEA-0xXXXXXXXX +AHs-
+AD4- Unit address should not have '0x'

Correct, let me fix it.

+AD4- +AD4- +-
+AD4- +AD4- +-	/+ACo- HDMI encoder on I2C bus +ACo-/
+AD4- +AD4- +-	i2c+AEA-0xXXXXXXXX +AHs-
+AD4- +AD4- +-		compatible +AD0- +ACI-...+ACIAOw-
+AD4- +AD4- +-
+AD4- +AD4- +-		encoder+AF8-node:encoder+AF8-node+AEA-0xXXXXXXXX+AHs-
+AD4- I2C addresses would be 8-bit only.

Indeed - copy-paste is evil :)

-Alexey