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

From: <Conor.Dooley@microchip.com>
To: <krzysztof.kozlowski+dt@linaro.org>, <damien.lemoal@opensource.wdc.com>
Cc: <daniel.lezcano@linaro.org>, <Eugeniy.Paltsev@synopsys.com>,
	<sam@ravnborg.org>, <daniel@ffwll.ch>, <paul.walmsley@sifive.com>,
	<vkoul@kernel.org>, <palmer@rivosinc.com>, <airlied@linux.ie>,
	<palmer@dabbelt.com>, <aou@eecs.berkeley.edu>,
	<robh+dt@kernel.org>, <masahiroy@kernel.org>,
	<geert@linux-m68k.org>, <niklas.cassel@wdc.com>,
	<dillon.minfei@gmail.com>, <dri-devel@lists.freedesktop.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<dmaengine@vger.kernel.org>, <linux-riscv@lists.infradead.org>,
	<fancer.lancer@gmail.com>, <thierry.reding@gmail.com>,
	<mail@conchuod.ie>
Subject: Re: [PATCH v5 04/13] dt-bindings: memory-controllers: add canaan k210 sram controller
Date: Sun, 10 Jul 2022 19:39:24 +0000	[thread overview]
Message-ID: <a516943f-3dac-70a0-3ebd-9f53fd307f25@microchip.com> (raw)
In-Reply-To: <20220705215213.1802496-5-mail@conchuod.ie>

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:

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
> 

