Hi,

On Thu, Dec 19, 2019 at 04:01:58PM +0200, Jyri Sarha wrote:
> On 19/12/2019 10:38, Maxime Ripard wrote:
> > On Thu, Dec 19, 2019 at 10:23:17AM +0200, Jyri Sarha wrote:
> >> Add dt-schema yaml bindig for J721E DSS, J721E version TI Keystone
> >> Display SubSystem.
> >>
> >> Version history:
> >>
> >> v2: no change
> >>
> >> v3: - reg-names: "wp" -> "wb"
> >>     - Add ports node
> >>     - Add includes to dts example
> >>     - reindent dts example
> >>
> >> v4: - Add descriptions to reg, clocks, and interrups properties
> >>     - Remove minItems when its value is the same as maxItems value
> >>
> >> Signed-off-by: Jyri Sarha <jsarha@ti.com>
> >> ---
> >>  .../bindings/display/ti/ti,j721e-dss.yaml     | 209 ++++++++++++++++++
> >>  1 file changed, 209 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/display/ti/ti,j721e-dss.yaml
> >>
> >> diff --git a/Documentation/devicetree/bindings/display/ti/ti,j721e-dss.yaml b/Documentation/devicetree/bindings/display/ti/ti,j721e-dss.yaml
> >> new file mode 100644
> >> index 000000000000..cd68c4294f9a
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/display/ti/ti,j721e-dss.yaml
> >> @@ -0,0 +1,209 @@
> >> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> >> +# Copyright 2019 Texas Instruments Incorporated
> >> +%YAML 1.2
> >> +---
> >> +$id: "http://devicetree.org/schemas/display/ti/ti,j721e-dss.yaml#"
> >> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> >> +
> >> +title: Texas Instruments J721E Display Subsystem
> >> +
> >> +maintainers:
> >> +  - Jyri Sarha <jsarha@ti.com>
> >> +  - Tomi Valkeinen <tomi.valkeinen@ti.com>
> >> +
> >> +description: |
> >> +  The J721E TI Keystone Display SubSystem with four output ports and
> >> +  four video planes. There is two full video planes and two "lite
> >> +  planes" without scaling support. The video ports can be connected to
> >> +  the SoC's DPI pins or to integrated display bridges on the SoC.
> >> +
> >> +properties:
> >> +  compatible:
> >> +    const: ti,j721e-dss
> >> +
> >> +  reg:
> >> +    maxItems: 17
> >> +    description: |
> >> +      Addresses to each DSS memory region described in the SoC's TRM.
> >> +      The reg-names refer to memory regions as follows:
> >> +      reg-names: Region Name in TRM:     Description:
> >> +      common_m   DSS0_DISPC_0_COMMON_M   DSS Master common register area
> >> +      common_s0  DSS0_DISPC_0_COMMON_SO  DSS Shared common register area 0
> >> +      common_s1  DSS0_DISPC_0_COMMON_S1  DSS Shared common register area 1
> >> +      common_s2  DSS0_DISPC_0_COMMON_S2  DSS Shared common register area 2
> >> +      vidl1      DSS0_VIDL1              VIDL1 light video plane 1
> >> +      vidl2      DSS0_VIDL2              VIDL2 light video plane 2
> >> +      vid1       DSS0_VID1               VID1 video plane 1
> >> +      vid2       DSS0_VID2               VID1 video plane 2
> >> +      ovr1       DSS0_OVR1               OVR1 overlay manager for vp1
> >> +      ovr2       DSS0_OVR2               OVR2 overlay manager for vp2
> >> +      ovr3       DSS0_OVR3               OVR1 overlay manager for vp3
> >> +      ovr4       DSS0_OVR4               OVR2 overlay manager for vp4
> >> +      vp1        DSS0_VP1                VP1 video port 1
> >> +      vp2        DSS0_VP2                VP1 video port 2
> >> +      vp3        DSS0_VP3                VP1 video port 3
> >> +      vp4        DSS0_VP4                VP1 video port 4
> >> +      wp         DSS0_WB                 Write Back registers
> >
> > I guess it applies to all your schemas in that patch series, but you
> > could just do something like
> >
> > reg:
> >   items:
> >     - description: DSS Master common register area
> >     - description: DSS Shared common register area 0
> >     - description: DSS Shared common register area 1
> >
>
> Ok, thanks. I was not sure if you can do that (still a newbie with
> yaml). What do you think about Peter Ujfalusi's suggestion of putting
> the descriptions to reg-names (and clock-names and  interrupt-names)?
> e.g. something like this:
>
>   reg-names:
>     items:
>       - const: common_m
>       - description: DSS Master common register area
>       - const: common_s0
>       - description: DSS Master common register area

No, you can't really intertwin them like this, this would mean that
you would expect twice the number of items.

You could do something like this:
reg-names:
  items:
    - const: common_m
      description: DSS Master common register area
    - const: common_s0
      description: DSS Master common register area

But on a more fundamental level, the register area is stored under
regs, while reg-names is just a label for that area, so having the
description under reg, and the labels under reg-names makes more sense
(well, to me at least :))

Maxiem