[PATCH v4 1/3] dt-bindings: clk: vc5: Add properties for configuring the SD/OE pin

* [PATCH v4 1/3] dt-bindings: clk: vc5: Add properties for configuring the SD/OE pin
@ 2021-07-01 18:20 Sean Anderson
  2021-07-02  7:14 ` Geert Uytterhoeven
  2021-07-02 14:12 ` Luca Ceresoli
  0 siblings, 2 replies; 7+ messages in thread
From: Sean Anderson @ 2021-07-01 18:20 UTC (permalink / raw)
  To: linux-clk, Luca Ceresoli
  Cc: Geert Uytterhoeven, Michael Turquette, Adam Ford, Stephen Boyd,
	Sean Anderson, Rob Herring, devicetree

These properties allow configuring the SD/OE pin as described in the
datasheet.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---

Changes in v4:
- Specify that bindings should specify these properties, but don't make
  any guarantees about the driver's behavior when they are not present.
- Clarify description of idt,(en|dis)able-shutdown properties.
- Make opposing properties mutually exclusive.
- Add these properties to the example.

Changes in v3:
- Add idt,disable-shutdown and idt,output-enable-active-low to allow for
  a default of not changing the SP/SH bits at all.

Changes in v2:
- Rename idt,sd-active-high to idt,output-enable-active-high
- Add idt,enable-shutdown

 .../bindings/clock/idt,versaclock5.yaml       | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml b/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml
index 28675b0b80f1..2631a175612b 100644
--- a/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml
+++ b/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml
@@ -30,6 +30,21 @@ description: |
     3 -- OUT3
     4 -- OUT4
 
+  The idt,(en|dis)able-shutdown and idt,output-enable-active-(high|low)
+  properties control the SH (en_global_shutdown) and SP bits of the
+  Primary Source and Shutdown Register, respectively. Their behavior is
+  summarized by the following table:
+
+  SH SP Output when the SD/OE pin is Low/High
+  == == =====================================
+   0  0 Active/Inactive
+   0  1 Inactive/Active
+   1  0 Active/Shutdown
+   1  1 Inactive/Shutdown
+
+  One of idt,(en|dis)able-shutdown and one of
+  idt,output-enable-active-(high|low) should be specified.
+
 maintainers:
   - Luca Ceresoli <luca@lucaceresoli.net>
 
@@ -64,6 +79,34 @@ properties:
     maximum: 22760
     description: Optional load capacitor for XTAL1 and XTAL2
 
+  idt,enable-shutdown:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Enable the shutdown functionality. The chip will be shut down if
+      the SD/OE pin is driven high. This corresponds to setting the SH
+      bit of the Primary Source and Shutdown Register.
+
+  idt,disable-shutdown:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Disable the shutdown functionality. The chip will never be shut
+      down based on the value of the SD/OE pin. This corresponds to
+      clearing the SH bit of the Primary Source and Shutdown Register.
+
+  idt,output-enable-active-high:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      This enables output when the SD/OE pin is high, and disables
+      output when the SD/OE pin is low. This corresponds to setting the
+      SP bit of the Primary Source and Shutdown Register.
+
+  idt,output-enable-active-low:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      This disables output when the SD/OE pin is high, and enables
+      output when the SD/OE pin is low. This corresponds to clearing the
+      SP bit of the Primary Source and Shutdown Register.
+
 patternProperties:
   "^OUT[1-4]$":
     type: object
@@ -109,6 +152,22 @@ allOf:
       required:
         - clock-names
         - clocks
+  - if:
+      true
+    then:
+      oneOf:
+        - required:
+            - idt,enable-shutdown
+        - required:
+            - idt,disable-shutdown
+  - if:
+      true
+    then:
+      oneOf:
+        - required:
+            - idt,output-enable-active-high
+        - required:
+            - idt,output-enable-active-low
 
 additionalProperties: false
 
@@ -138,6 +197,10 @@ examples:
             clocks = <&ref25m>;
             clock-names = "xin";
 
+            /* Set the SD/OE pin's settings */
+            idt,disable-shutdown;
+            idt,output-enable-active-low;
+
             OUT1 {
                 idt,drive-mode = <VC5_CMOSD>;
                 idt,voltage-microvolts = <1800000>;
-- 
2.25.1


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