Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Conor Dooley <mail@conchuod.ie>
To:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Serge Semin <fancer.lancer@gmail.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Palmer Dabbelt <palmer@rivosinc.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Conor Dooley <conor.dooley@microchip.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Niklas Cassel <niklas.cassel@wdc.com>,
        Dillon Min <dillon.minfei@gmail.com>,
        Heng Sia <jee.heng.sia@intel.com>,
        Jose Abreu <joabreu@synopsys.com>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
        alsa-devel@alsa-project.org, linux-spi@vger.kernel.org,
        linux-riscv@lists.infradead.org
Subject: [PATCH v2 07/16] dt-bindings: memory-controllers: add canaan k210 sram controller
Date:   Mon, 27 Jun 2022 20:39:55 +0100
Message-Id: <20220627194003.2395484-8-mail@conchuod.ie>
In-Reply-To: <20220627194003.2395484-1-mail@conchuod.ie>
References: <20220627194003.2395484-1-mail@conchuod.ie>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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>
---
I made myself maintainer since I didn't have anywhere else
to point a finger, but I am happy to let someone else take
that on!

The corresponding U-Boot code seems to be:
static int sram_init(void)
{
	int ret, i;
	const char * const banks[] = { "sram0", "sram1", "aisram" };
	ofnode memory;
	struct clk clk;

	/* Enable RAM clocks */
	memory = ofnode_by_compatible(ofnode_null(), "canaan,k210-sram");
	if (ofnode_equal(memory, ofnode_null()))
		return -ENOENT;

	for (i = 0; i < ARRAY_SIZE(banks); i++) {
		ret = clk_get_by_name_nodev(memory, banks[i], &clk);
		if (ret)
			continue;

		ret = clk_enable(&clk);
		clk_free(&clk);
		if (ret)
			return ret;
	}

	return 0;
}

Which, without having the hardware etc, I suspect is likely to keep
working after the move.
---
 .../memory-controllers/canaan,k210-sram.yaml  | 53 +++++++++++++++++++
 1 file changed, 53 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..837eb65854fc
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/canaan,k210-sram.yaml
@@ -0,0 +1,53 @@
+# 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 initialised and programmed by
+  firmware, but an OS might want to read its registers for error reporting
+  purposes and to learn about the DRAM topology.
+
+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";
+    };
+
-- 
2.36.1