Thread (24 messages) 24 messages, 6 authors, 2019-08-29

Re: [PATCH v3 02/11] dt-bindings: clock: imx-lpcg: add support to parse clocks from device tree

From: Shawn Guo <shawnguo@kernel.org>
Date: 2019-08-03 13:50:52
Also in: linux-clk, linux-devicetree

On Tue, Jul 16, 2019 at 11:00:56PM +0800, Dong Aisheng wrote:
quoted hunk ↗ jump to hunk
MX8QM and MX8QXP LPCG Clocks are mostly the same except they may reside
in different subsystems across CPUs and also vary a bit on the availability.

Same as SCU clock, we want to move the clock definition into device tree
which can fully decouple the dependency of Clock ID definition from device
tree and make us be able to write a fully generic lpcg clock driver.

And we can also use the existence of clock nodes in device tree to address
the device and clock availability differences across different SoCs.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
ChangeLog:
v2->v3:
 * no changes
v1->v2:
 * Update example
 * Add power domain property
---
 .../devicetree/bindings/clock/imx8qxp-lpcg.txt     | 34 ++++++++++++++++++----
 1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/clock/imx8qxp-lpcg.txt b/Documentation/devicetree/bindings/clock/imx8qxp-lpcg.txt
index 965cfa4..6fc2fd8 100644
--- a/Documentation/devicetree/bindings/clock/imx8qxp-lpcg.txt
+++ b/Documentation/devicetree/bindings/clock/imx8qxp-lpcg.txt
@@ -11,6 +11,21 @@ enabled by these control bits, it might still not be running based
 on the base resource.
 
 Required properties:
+- compatible:		Should be one of:
+			  "fsl,imx8qxp-lpcg"
+			  "fsl,imx8qm-lpcg" followed by "fsl,imx8qxp-lpcg".
+- reg:			Address and length of the register set.
+- #clock-cells:		Should be 1. One LPCG supports multiple clocks.
+- clocks:		Input parent clocks phandle array for each clock.
+- bit-offset:		An integer array indicating the bit offset for each clock.
I guess that the driver should be able to figure bit offset from
'clock-indices' property.
+- hw-autogate:		Boolean array indicating whether supports HW autogate for
+			each clock.
Not sure why it needs to be a property in DT.  Or asking it different
way, when it should be true and when false?

Shawn
quoted hunk ↗ jump to hunk
+- clock-output-names:	Shall be the corresponding names of the outputs.
+			NOTE this property must be specified in the same order
+			as the clock bit-offset and hw-autogate property.
+- power-domains:	Should contain the power domain used by this clock.
+
+Legacy binding (DEPRECATED):
 - compatible:	Should be one of:
 		  "fsl,imx8qxp-lpcg-adma",
 		  "fsl,imx8qxp-lpcg-conn",
@@ -33,10 +48,17 @@ Examples:
 
 #include <dt-bindings/clock/imx8qxp-clock.h>
 
-conn_lpcg: clock-controller@5b200000 {
-	compatible = "fsl,imx8qxp-lpcg-conn";
-	reg = <0x5b200000 0xb0000>;
+sdhc0_lpcg: clock-controller@5b200000 {
+	compatible = "fsl,imx8qxp-lpcg";
+	reg = <0x5b200000 0x10000>;
 	#clock-cells = <1>;
+	clocks = <&sdhc0_clk IMX_SC_PM_CLK_PER>,
+		 <&conn_ipg_clk>, <&conn_axi_clk>;
+	bit-offset = <0 16 20>;
+	clock-output-names = "sdhc0_lpcg_per_clk",
+			     "sdhc0_lpcg_ipg_clk",
+			     "sdhc0_lpcg_ahb_clk";
+	power-domains = <&pd IMX_SC_R_SDHC_0>;
 };
 
 usdhc1: mmc@5b010000 {
@@ -44,8 +66,8 @@ usdhc1: mmc@5b010000 {
 	interrupt-parent = <&gic>;
 	interrupts = <GIC_SPI 232 IRQ_TYPE_LEVEL_HIGH>;
 	reg = <0x5b010000 0x10000>;
-	clocks = <&conn_lpcg IMX8QXP_CONN_LPCG_SDHC0_IPG_CLK>,
-		 <&conn_lpcg IMX8QXP_CONN_LPCG_SDHC0_PER_CLK>,
-		 <&conn_lpcg IMX8QXP_CONN_LPCG_SDHC0_HCLK>;
+	clocks = <&sdhc0_lpcg 1>,
+		 <&sdhc0_lpcg 0>,
+		 <&sdhc0_lpcg 2>;
 	clock-names = "ipg", "per", "ahb";
 };
-- 
2.7.4
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