[PATCH v4 13/18] dt-bindings: clock: imx8m-clock: support spread spectrum clocking

[Dario Binacchi]

The patch adds the DT bindings for enabling and tuning spread spectrum
clocking generation.

Signed-off-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>

 - Drop "fsl,ssc-clocks" property. The other added properties now refer
   to the clock list.
 - Updated minItems and maxItems of
   - clocks
   - clock-names
   - fsl,ssc-modfreq-hz
   - fsl,ssc-modrate-percent
   - fsl,ssc-modmethod
 - Updated the dts examples

 - Added in v3
 - The dt-bindings have been moved from fsl,imx8m-anatop.yaml to
   imx8m-clock.yaml. The anatop device (fsl,imx8m-anatop.yaml) is
   indeed more or less a syscon, so it represents a memory area
   accessible by ccm (imx8m-clock.yaml) to setup the PLLs.

 - Add "allOf:" and place it after "required:" block, like in the
   example schema.
 - Move the properties definition to the top-level.
 - Drop unit types as requested by the "make dt_binding_check" command.

---

(no changes since v1)

 .../bindings/clock/imx8m-clock.yaml           | 77 +++++++++++++++++--
 1 file changed, 71 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml
index c643d4a81478..83036f6d2274 100644
--- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml
+++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml
@@ -29,12 +29,12 @@ properties:
     maxItems: 2
 
   clocks:
-    minItems: 6
-    maxItems: 7
+    minItems: 7
+    maxItems: 10
 
   clock-names:
-    minItems: 6
-    maxItems: 7
+    minItems: 7
+    maxItems: 10
 
   '#clock-cells':
     const: 1
@@ -43,6 +43,34 @@ properties:
       ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8m-clock.h
       for the full list of i.MX8M clock IDs.
 
+  fsl,ssc-modfreq-hz:
+    description:
+      The values of modulation frequency (Hz unit) for each clock
+      supporting spread spectrum.
+    minItems: 7
+    maxItems: 10
+
+  fsl,ssc-modrate-percent:
+    description:
+      The percentage values of modulation rate for each clock
+      supporting spread spectrum.
+    minItems: 7
+    maxItems: 10
+
+  fsl,ssc-modmethod:
+    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
+    description:
+      The modulation techniques for each clock supporting spread
+      spectrum.
+    minItems: 7
+    maxItems: 10
+    items:
+      enum:
+        - ""
+        - down-spread
+        - up-spread
+        - center-spread
+
 required:
   - compatible
   - reg
@@ -76,6 +104,10 @@ allOf:
             - const: clk_ext2
             - const: clk_ext3
             - const: clk_ext4
+        fsl,ssc-modfreq-hz: false
+        fsl,ssc-modrate-percent: false
+        fsl,ssc-modmethod: false
+
     else:
       properties:
         clocks:
@@ -86,6 +118,10 @@ allOf:
             - description: ext2 clock input
             - description: ext3 clock input
             - description: ext4 clock input
+            - description: audio1 PLL input
+            - description: audio2 PLL input
+            - description: dram PLL input
+            - description: video PLL input
 
         clock-names:
           items:
@@ -95,20 +131,49 @@ allOf:
             - const: clk_ext2
             - const: clk_ext3
             - const: clk_ext4
+            - const: audio_pll1
+            - const: audio_pll2
+            - const: dram_pll
+            - const: video_pll
 
 additionalProperties: false
 
 examples:
   # Clock Control Module node:
   - |
+    #include <dt-bindings/clock/imx8mm-clock.h>
+
     clock-controller at 30380000 {
         compatible = "fsl,imx8mm-ccm";
         reg = <0x30380000 0x10000>;
         #clock-cells = <1>;
         clocks = <&osc_32k>, <&osc_24m>, <&clk_ext1>, <&clk_ext2>,
-                 <&clk_ext3>, <&clk_ext4>;
+                 <&clk_ext3>, <&clk_ext4>,
+                 <&anatop IMX8MM_ANATOP_AUDIO_PLL1>,
+                 <&anatop IMX8MM_ANATOP_AUDIO_PLL1>,
+                 <&anatop IMX8MM_ANATOP_DRAM_PLL>,
+                 <&anatop IMX8MM_ANATOP_VIDEO_PLL>;
         clock-names = "osc_32k", "osc_24m", "clk_ext1", "clk_ext2",
-                      "clk_ext3", "clk_ext4";
+                      "clk_ext3", "clk_ext4", "audio_pll1", "audio_pll2",
+                      "dram_pll", "video_pll";
+        fsl,ssc-modfreq-hz = <0>, <0>, <0>, <0>,
+                             <0>, <0>,
+                             <6818>,
+                             <0>,
+                             <0>,
+                             <2419>;
+        fsl,ssc-modrate-percent = <0>, <0>, <0>, <0>,
+                             <0>, <0>,
+                             <3>,
+                             <0>,
+                             <0>,
+                             <7>;
+        fsl,ssc-modmethod = "", "", "", "",
+                            "", "",
+                            "down-spread",
+                            "",
+                            "",
+                            "center-spread";
     };
 
   - |
-- 
2.43.0