[v9,4/6] clk: max77686: Improve Maxim 77686 PMIC clocks binding

Commit Message

Javier Martinez Canillas Aug. 18, 2014, 8:33 a.m. UTC

Like most clock drivers, the Maxim 77686 PMIC clock binding
follows the convention that the "#clock-cells" property is
used to specify the number of cells in a clock provider.

But the binding document is not clear enough that it shall
be set to 1 since the PMIC support multiple clocks outputs.

Also, explain that the clocks identifiers are defined in a
header file that can be included by Device Tree source with
client nodes to avoid using magic numbers.

Finally, add "clock-output-names" as an optional property
since now is supported by the clock driver.

Signed-off-by: Javier Martinez Canillas <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Doug Anderson <[e-mail]>
Reviewed-by: Mike Turquette <[e-mail]>
Acked-by: Mike Turquette <[e-mail]>
---

Changes since v6: None

Changes since v5:
 - Fix generic driver changes merged into max77802 clock patch by mistake.
   Suggested by Yadwinder Singh Brar.
 - Register clock lookups using clk_register_clkdev() instead of doing manually.
 - Use the managed devm_clk_register() function and remove clk un-registration.
 - Add "clock-output-names" property support. Suggested by Yadwinder Singh Brar.
 - Return the rate unconditionally in recalc_rate. Suggested by Mike Turquette.

Changes since v4: None

Changes since v3:
 - Don't change clock-names property to make clear that it's
   the consumer clock name and should not match the producer clock.
   Suggested by Doug Anderson.
---
 .../devicetree/bindings/clock/maxim,max77686.txt         | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Patch

diff --git a/Documentation/devicetree/bindings/clock/maxim,max77686.txt b/Documentation/devicetree/bindings/clock/maxim,max77686.txt
index 96ce71b..9c40739 100644
--- a/Documentation/devicetree/bindings/clock/maxim,max77686.txt
+++ b/Documentation/devicetree/bindings/clock/maxim,max77686.txt
@@ -9,13 +9,21 @@  The MAX77686 contains three 32.768khz clock outputs that can be controlled
 Following properties should be presend in main device node of the MFD chip.
 
 Required properties:
-- #clock-cells: simple one-cell clock specifier format is used, where the
-  only cell is used as an index of the clock inside the provider. Following
-  indices are allowed:
+
+- #clock-cells: from common clock binding; shall be set to 1.
+
+Optional properties:
+- clock-output-names: From common clock binding.
+
+Each clock is assigned an identifier and client nodes can use this identifier
+to specify the clock which they consume. Following indices are allowed:
     - 0: 32khz_ap clock,
     - 1: 32khz_cp clock,
     - 2: 32khz_pmic clock.
 
+Clocks are defined as preprocessor macros in dt-bindings/clock/maxim,max77686.h
+header and can be used in device tree sources.
+
 Example: Node of the MFD chip
 
 	max77686: max77686@09 {
@@ -34,5 +42,5 @@  Example: Clock consumer node
 		compatible = "bar,foo";
 		/* ... */
 		clock-names = "my-clock";
-		clocks = <&max77686 2>;
+		clocks = <&max77686 MAX77686_CLK_PMIC>;
 	};