[PATCH v5 2/5] dt-bindings: ti: dpll: add spread spectrum support

From: Dario Binacchi
Date: Sun Apr 18 2021 - 10:58:13 EST


DT bindings for enabling and adjusting spread spectrum clocking have
been added.

Signed-off-by: Dario Binacchi <dariobin@xxxxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

---

(no changes since v4)

Changes in v4:
- Add Rob Herring review tag.

Changes in v3:
- Add '-hz' suffix to "ti,ssc-modfreq" binding.

.../devicetree/bindings/clock/ti/dpll.txt | 20 +++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/ti/dpll.txt b/Documentation/devicetree/bindings/clock/ti/dpll.txt
index df57009ff8e7..37a7cb6ad07d 100644
--- a/Documentation/devicetree/bindings/clock/ti/dpll.txt
+++ b/Documentation/devicetree/bindings/clock/ti/dpll.txt
@@ -42,6 +42,11 @@ Required properties:
"idlest" - contains the idle status register base address
"mult-div1" - contains the multiplier / divider register base address
"autoidle" - contains the autoidle register base address (optional)
+ "ssc-deltam" - DPLL supports spread spectrum clocking (SSC), contains
+ the frequency spreading register base address (optional)
+ "ssc-modfreq" - DPLL supports spread spectrum clocking (SSC), contains
+ the modulation frequency register base address
+ (optional)
ti,am3-* dpll types do not have autoidle register
ti,omap2-* dpll type does not support idlest / autoidle registers

@@ -51,6 +56,14 @@ Optional properties:
- ti,low-power-stop : DPLL supports low power stop mode, gating output
- ti,low-power-bypass : DPLL output matches rate of parent bypass clock
- ti,lock : DPLL locks in programmed rate
+ - ti,min-div : the minimum divisor to start from to round the DPLL
+ target rate
+ - ti,ssc-deltam : DPLL supports spread spectrum clocking, frequency
+ spreading in permille (10th of a percent)
+ - ti,ssc-modfreq-hz : DPLL supports spread spectrum clocking, spread
+ spectrum modulation frequency
+ - ti,ssc-downspread : DPLL supports spread spectrum clocking, boolean
+ to enable the downspread feature

Examples:
dpll_core_ck: dpll_core_ck@44e00490 {
@@ -83,3 +96,10 @@ Examples:
clocks = <&sys_ck>, <&sys_ck>;
reg = <0x0500>, <0x0540>;
};
+
+ dpll_disp_ck: dpll_disp_ck {
+ #clock-cells = <0>;
+ compatible = "ti,am3-dpll-no-gate-clock";
+ clocks = <&sys_clkin_ck>, <&sys_clkin_ck>;
+ reg = <0x0498>, <0x0448>, <0x0454>, <0x044c>, <0x0450>;
+ };
--
2.17.1