[RFC PATCHv2 3/9] dt-bindings: display/ti: add am65x-dss bindings

[Tomi Valkeinen]

Hi Rob,

On 25/06/18 21:59, Rob Herring wrote:
> On Mon, Jun 18, 2018 at 04:22:36PM +0300, Tomi Valkeinen wrote:
>> Add DT bindings for Texas Instruments AM65x SoC Display Subsystem.  The
>> DSS7 on AM65x SoC has two video ports (DPI and OLDI) and two video
>> pipelines.
>>
>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
>> Cc: devicetree at vger.kernel.org
>> ---
>>  .../bindings/display/ti/ti,am6-dss.txt           | 16 ++++++++++++++++
>>  1 file changed, 16 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/display/ti/ti,am6-dss.txt
>>
>> diff --git a/Documentation/devicetree/bindings/display/ti/ti,am6-dss.txt b/Documentation/devicetree/bindings/display/ti/ti,am6-dss.txt
>> new file mode 100644
>> index 000000000000..3466f095fb84
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/ti/ti,am6-dss.txt
>> @@ -0,0 +1,16 @@
>> +Texas Instruments AM65x Display Subsystem
>> +==========================================
>> +
>> +Required properties:
>> +- compatible: "ti,am65x-dss", "ti,am6-dss"
> 
> Why do you need 2 compatibles? What's the difference for the 'x' in 
> 'am65x'?

For now we have only one AM6xx SoC, but probably there will be more
variants, possibly with slightly different DSS setups (say, a single
output version). But then, maybe all the variants will have the exact
same DSS.

I'm not quite sure how to handle it here, so I added am6-dss as a base,
so that in the DT file we could have the compatible as
"exact-model-name","am6-dss", and only handle am6-dss in the driver
unless we get models with different DSS features.

But then I probably should not use am65x, and instead use the exact
model name here (am654), even if the last number in the model should not
affect DSS.

>> +- reg: address and length of the register spaces for DSS submodules
>> +- reg-names: "common", "vidl1", "vid", "ovr1", "ovr2", "vp1", "vp2"
>> +- clocks: phandle to fclk, vp1, and vp2 clocks
>> +- clock-names: "fck", "vp1", "vp2"
> 
> fck or fclk?

fck. I'll fix that.

>> +- interrupts: phandle to the DISPC interrupt
>> +- syscon: phandle to syscon device handling OLDI_PWRDN_TX (partition 1 of
>> +  AM654 CTRL MMR0)
>> +
>> +The DSS outputs are described using the device graphs as documented in
>> +Documentation/devicetree/bindings/graph.txt. AM6 DSS has a DPI output as port 0
>> +and an OLDI output as port 1.
> 
> What's OLDI?

OpenLDI (https://en.wikipedia.org/wiki/OpenLDI). I should probably not
abbreviate it here.

 Tomi


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