[1/7] dt-bindings: sram: Document Allwinner H616 VE SRAM

The Allwinner H616 has two switchable peripheral SRAM regions:

- The VE SRAM is a 2 MB dedicated SRAM for the Video Engine. CPU access
  to this region is enabled by default. CPU access can be disabled,
  after which reads will show the same stale value for all addresses,
  while writes are ignored.

  The mux value for this region is different from previous generations,
  and thus needs a completely new compatible.

- The SRAM C region is an alias of the first 128 KB of VE SRAM, plus 64
  KB of DE SRAM. The latter is otherwise unaccessible from the CPU. When
  CPU access is disabled, the whole region reads as zero, while writes
  are ignored.

  The mux value for this region is the same as on the A64 and H6. The
  existing compatible for the A64 already covers this.

Add the compatible for the VE SRAM to the list of covered compatibles in
the generic SRAM region binding.

Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
---
 Documentation/devicetree/bindings/sram/sram.yaml | 1 +
 1 file changed, 1 insertion(+)
  

Dne torek, 24. marec 2026 ob 17:43:49 Srednjeevropski standardni čas je Chen-Yu Tsai napisal(a):
> The Allwinner H616 has two switchable peripheral SRAM regions:
> 
> - The VE SRAM is a 2 MB dedicated SRAM for the Video Engine. CPU access
>   to this region is enabled by default. CPU access can be disabled,
>   after which reads will show the same stale value for all addresses,
>   while writes are ignored.
> 
>   The mux value for this region is different from previous generations,
>   and thus needs a completely new compatible.
> 
> - The SRAM C region is an alias of the first 128 KB of VE SRAM, plus 64
>   KB of DE SRAM. The latter is otherwise unaccessible from the CPU. When
>   CPU access is disabled, the whole region reads as zero, while writes
>   are ignored.
> 
>   The mux value for this region is the same as on the A64 and H6. The
>   existing compatible for the A64 already covers this.
> 
> Add the compatible for the VE SRAM to the list of covered compatibles in
> the generic SRAM region binding.
> 
> Signed-off-by: Chen-Yu Tsai <wens@kernel.org>

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej
  

On Wed, 25 Mar 2026 00:43:49 +0800, Chen-Yu Tsai wrote:
> The Allwinner H616 has two switchable peripheral SRAM regions:
> 
> - The VE SRAM is a 2 MB dedicated SRAM for the Video Engine. CPU access
>   to this region is enabled by default. CPU access can be disabled,
>   after which reads will show the same stale value for all addresses,
>   while writes are ignored.
> 
>   The mux value for this region is different from previous generations,
>   and thus needs a completely new compatible.
> 
> - The SRAM C region is an alias of the first 128 KB of VE SRAM, plus 64
>   KB of DE SRAM. The latter is otherwise unaccessible from the CPU. When
>   CPU access is disabled, the whole region reads as zero, while writes
>   are ignored.
> 
>   The mux value for this region is the same as on the A64 and H6. The
>   existing compatible for the A64 already covers this.
> 
> Add the compatible for the VE SRAM to the list of covered compatibles in
> the generic SRAM region binding.
> 
> Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
> ---
>  Documentation/devicetree/bindings/sram/sram.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 

Acked-by: Rob Herring (Arm) <robh@kernel.org>