Hi Jerome, Jianxin:

see my comments

On 10:58 Wed 24 Oct     , Jerome Brunet wrote:

On Thu, 2018-10-18 at 13:07 +0800, Jianxin Pan wrote:

quoted

From: Yixun Lan <redacted>

Document the MMC sub clock controller driver, the potential consumer
of this driver is MMC or NAND. Also add four clock bindings IDs which
provided by this driver.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Yixun Lan <redacted>
Signed-off-by: Jianxin Pan <redacted>
---
 .../devicetree/bindings/clock/amlogic,mmc-clkc.txt | 31 ++++++++++++++++++++++
 include/dt-bindings/clock/amlogic,mmc-clkc.h       | 17 ++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt
 create mode 100644 include/dt-bindings/clock/amlogic,mmc-clkc.h

diff --git a/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt b/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt
new file mode 100644
index 0000000..9e6d343
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt

@@ -0,0 +1,31 @@
+* Amlogic MMC Sub Clock Controller Driver
+
+The Amlogic MMC clock controller generates and supplies clock to support
+MMC and NAND controller
+
+Required Properties:
+
+- compatible: should be:
+		"amlogic,gx-mmc-clkc"
+		"amlogic,axg-mmc-clkc"
+
+- #clock-cells: should be 1.
+- clocks: phandles to clocks corresponding to the clock-names property
+- clock-names: list of parent clock names
+	- "clkin0", "clkin1"
+
+Parent node should have the following properties :
+- compatible: "amlogic,axg-mmc-clkc", "syscon".
+- reg: base address and size of the MMC control register space.

I get why Stephen is confused by your description, I am too. The example
contradict the documentation.

The  documentation above says that the parent node should be a syscon with the
mmc register space.

But your example shows this in the node itself.

yes, I think the documentation need to be fixed

for the final solution, we decide to make 'mmc-clkc' an independent node
instead of being a sub-node of 'mmc', so both of them may exist in parallel..

the DT part may like this:

			sd_emmc_c_clkc: clock-controller at 7000 {
				compatible = "amlogic,axg-mmc-clkc", "syscon";
				reg = <0x0 0x7000 0x0 0x4>;
				...
			};

			sd_emmc_c: mmc at 7000 {
				compatible = "amlogic,axg-mmc";
				reg = <0x0 0x7000 0x0 0x800>;
				...
			};

quoted

+
+Example: Clock controller node:
+
+sd_mmc_c_clkc: clock-controller at 7000 {
+	compatible = "amlogic,axg-mmc-clkc", "syscon";
+	reg = <0x0 0x7000 0x0 0x4>;
+	#clock-cells = <1>;
+
+	clock-names = "clkin0", "clkin1";
+	clocks = <&clkc CLKID_SD_MMC_C_CLK0>,
+		 <&clkc CLKID_FCLK_DIV2>;
+};

diff --git a/include/dt-bindings/clock/amlogic,mmc-clkc.h b/include/dt-bindings/clock/amlogic,mmc-clkc.h
new file mode 100644
index 0000000..162b949
--- /dev/null
+++ b/include/dt-bindings/clock/amlogic,mmc-clkc.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
+/*
+ * Meson MMC sub clock tree IDs
+ *
+ * Copyright (c) 2018 Amlogic, Inc. All rights reserved.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#ifndef __MMC_CLKC_H
+#define __MMC_CLKC_H
+
+#define CLKID_MMC_DIV				1
+#define CLKID_MMC_PHASE_CORE			2
+#define CLKID_MMC_PHASE_TX			3
+#define CLKID_MMC_PHASE_RX			4
+
+#endif

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-- 
Yixun Lan (dlan)
Gentoo Linux Developer
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