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[RfC,v1,2/5] dt-bindings: arm: amlogic: Add support for GXL S905W and the P281 board

Message ID 20180624182814.31691-3-martin.blumenstingl@googlemail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Martin Blumenstingl June 24, 2018, 6:28 p.m. UTC
S905W SoC is another SoC from the GXL family. It is a cost-reduced
version of the S905X SoC. The following differences are known:
- S905W supports HDMI resolutions up to 4k@30fps (while S905X support
  resolutions up to 4k@60fps)
- the built-in video decoders of S905W decode up to 4k@30fps (while
  S905X supports decoding up to 4k@60fps)
- CPU speed on S905W is limited to 1.2GHz (compared to 1.5GHz on S905X,
  this is handled in the SCPI firmware)
- the DRAM interface on S905W is limited to 16-bit (GXL supports both,
  16-bit and 32-bit)

Notes based on Amlogic's GPL kernel sources:
- the P281 is a development board from Amlogic which uses the S905W SoC.
  Amlogic's GPL kernel sources indicate that it uses the same PCB layout
  as the "P231" board (and simply replaces the S905D from the original
  P231 board with a S905W SoC).
- it is assumed that the S905W SoC is pin-compatible with the S905X SoC
  since Amlogic's GPL kernel sources use the same driver for both SoCs.
- gxl_p281_1g.dts contains a comment which mentions that "max gp pll for
  gpu is 650M, temporarily disabled". However, it seems to boot fine
  with 744MHz (as used on GXBB and the other GXL SoCs).

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 Documentation/devicetree/bindings/arm/amlogic.txt | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Rob Herring June 25, 2018, 9:03 p.m. UTC | #1
On Sun, Jun 24, 2018 at 08:28:11PM +0200, Martin Blumenstingl wrote:
> S905W SoC is another SoC from the GXL family. It is a cost-reduced
> version of the S905X SoC. The following differences are known:
> - S905W supports HDMI resolutions up to 4k@30fps (while S905X support
>   resolutions up to 4k@60fps)
> - the built-in video decoders of S905W decode up to 4k@30fps (while
>   S905X supports decoding up to 4k@60fps)
> - CPU speed on S905W is limited to 1.2GHz (compared to 1.5GHz on S905X,
>   this is handled in the SCPI firmware)
> - the DRAM interface on S905W is limited to 16-bit (GXL supports both,
>   16-bit and 32-bit)
> 
> Notes based on Amlogic's GPL kernel sources:
> - the P281 is a development board from Amlogic which uses the S905W SoC.
>   Amlogic's GPL kernel sources indicate that it uses the same PCB layout
>   as the "P231" board (and simply replaces the S905D from the original
>   P231 board with a S905W SoC).
> - it is assumed that the S905W SoC is pin-compatible with the S905X SoC
>   since Amlogic's GPL kernel sources use the same driver for both SoCs.
> - gxl_p281_1g.dts contains a comment which mentions that "max gp pll for
>   gpu is 650M, temporarily disabled". However, it seems to boot fine
>   with 744MHz (as used on GXBB and the other GXL SoCs).
> 
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---
>  Documentation/devicetree/bindings/arm/amlogic.txt | 6 ++++++
>  1 file changed, 6 insertions(+)

Reviewed-by: Rob Herring <robh@kernel.org>
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Patch

diff --git a/Documentation/devicetree/bindings/arm/amlogic.txt b/Documentation/devicetree/bindings/arm/amlogic.txt
index 69880560c0f0..33c672284963 100644
--- a/Documentation/devicetree/bindings/arm/amlogic.txt
+++ b/Documentation/devicetree/bindings/arm/amlogic.txt
@@ -41,6 +41,10 @@  Boards with the Amlogic Meson GXL S905D SoC shall have the following properties:
   Required root node property:
     compatible: "amlogic,s905d", "amlogic,meson-gxl";
 
+Boards with the Amlogic Meson GXL S905W SoC shall have the following properties:
+  Required root node property:
+    compatible: "amlogic,s905w", "amlogic,meson-gxl";
+
 Boards with the Amlogic Meson GXM S912 SoC shall have the following properties:
   Required root node property:
     compatible: "amlogic,s912", "amlogic,meson-gxm";
@@ -79,6 +83,8 @@  Board compatible values (alphabetically, grouped by SoC):
   - "amlogic,p230" (Meson gxl s905d)
   - "amlogic,p231" (Meson gxl s905d)
 
+  - "amlogic,p281" (Meson gxl s905w)
+
   - "amlogic,q200" (Meson gxm s912)
   - "amlogic,q201" (Meson gxm s912)
   - "khadas,vim2" (Meson gxm s912)