Re: [PATCH v5 04/13] dt-bindings: memory-controllers: add canaan k210 sram controller

Damien Le Moal
2022-07-10T23:21:23Z

On 7/11/22 04:39, Conor.Dooley@microchip.com wrote:
> Damien, Krzysztof,
>
> I know this particular version has not been posted for all that
> long, but this binding is (functionally) unchanged for a few
> versions now. Are you happy with this approach Damien?
> U-Boot only cares about the compatible & the clocks property,
> not the regs etc.
>
> I (lazily) tested it in U-Boot with the following diff:

If both the kernel and u-boot still work as expected with this change, I
am OK with it.

>
> diff --git a/arch/riscv/dts/k210.dtsi b/arch/riscv/dts/k210.dtsi
> index 3cc8379133..314db88340 100644
> --- a/arch/riscv/dts/k210.dtsi
> +++ b/arch/riscv/dts/k210.dtsi
> @@ -82,11 +82,14 @@
>
> sram: memory@80000000 {
> device_type = "memory";
> + reg = <0x80000000 0x400000>, /* sram0 4 MiB */
> + <0x80400000 0x200000>, /* sram1 2 MiB */
> + <0x80600000 0x200000>; /* aisram 2 MiB */
> + u-boot,dm-pre-reloc;
> + };
> +
> + sram_controller: memory-controller {
> compatible = "canaan,k210-sram";
> - reg = <0x80000000 0x400000>,
> - <0x80400000 0x200000>,
> - <0x80600000 0x200000>;
> - reg-names = "sram0", "sram1", "aisram";
> clocks = <&sysclk K210_CLK_SRAM0>,
> <&sysclk K210_CLK_SRAM1>,
> <&sysclk K210_CLK_AI>;
>
> If so, could you queue this for 5.20 please Krzysztof, unless
> you've got concerns about it?
>
> Thanks,
> Conor.
>
> On 05/07/2022 22:52, Conor Dooley wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> From: Conor Dooley <conor.dooley@microchip.com>
>>
>> The k210 U-Boot port has been using the clocks defined in the
>> devicetree to bring up the board's SRAM, but this violates the
>> dt-schema. As such, move the clocks to a dedicated node with
>> the same compatible string & document it.
>>
>> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
>> ---
>> .../memory-controllers/canaan,k210-sram.yaml | 52 +++++++++++++++++++
>> 1 file changed, 52 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/memory-controllers/canaan,k210-sram.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/memory-controllers/canaan,k210-sram.yaml b/Documentation/devicetree/bindings/memory-controllers/canaan,k210-sram.yaml
>> new file mode 100644
>> index 000000000000..f81fb866e319
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/memory-controllers/canaan,k210-sram.yaml
>> @@ -0,0 +1,52 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/memory-controllers/canaan,k210-sram.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Canaan K210 SRAM memory controller
>> +
>> +description:
>> + The Canaan K210 SRAM memory controller is responsible for the system's 8 MiB
>> + of SRAM. The controller is initialised by the bootloader, which configures
>> + its clocks, before OS bringup.
>> +
>> +maintainers:
>> + - Conor Dooley <conor@kernel.org>
>> +
>> +properties:
>> + compatible:
>> + enum:
>> + - canaan,k210-sram
>> +
>> + clocks:
>> + minItems: 1
>> + items:
>> + - description: sram0 clock
>> + - description: sram1 clock
>> + - description: aisram clock
>> +
>> + clock-names:
>> + minItems: 1
>> + items:
>> + - const: sram0
>> + - const: sram1
>> + - const: aisram
>> +
>> +required:
>> + - compatible
>> + - clocks
>> + - clock-names
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + #include <dt-bindings/clock/k210-clk.h>
>> + memory-controller {
>> + compatible = "canaan,k210-sram";
>> + clocks = <&sysclk K210_CLK_SRAM0>,
>> + <&sysclk K210_CLK_SRAM1>,
>> + <&sysclk K210_CLK_AI>;
>> + clock-names = "sram0", "sram1", "aisram";
>> + };
>> --
>> 2.37.0
>>
>

--
Damien Le Moal
Western Digital Research