diff mbox series

[v4,3/5] dt-bindings: usb: dwc3: add reference clock period fractional adjustment

Message ID 20220114044230.2677283-4-robert.hancock@calian.com
State New
Headers show
Series Xilinx ZynqMP USB fixes | expand

Commit Message

Robert Hancock Jan. 14, 2022, 4:42 a.m. UTC 
Document the new snps,ref-clock-fladj property which can be used to set
the fractional portion of the reference clock period.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 .../devicetree/bindings/usb/snps,dwc3.yaml          | 13 +++++++++++++
 1 file changed, 13 insertions(+)
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Patch

diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
index d29ffcd27472..5872a4470b16 100644
--- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
+++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
@@ -266,6 +266,19 @@  properties:
     minimum: 1
     maximum: 0x3ff
 
+  snps,ref-clock-fladj:
+    description:
+      Value for GFLADJ_REFCLK_FLADJ field of GFLADJ register for the
+      fractional portion of the reference clock period in nanoseconds,
+      when the hardware set default does not match the actual
+      clock. Calculated via
+      ((125000/ref_clk_period_integer)-(125000/ref_clk_period)) * ref_clk_period
+      where ref_clk_period_integer is the period specified in GUCTL_REFCLKPER and
+      ref_clk_period is the period including fractional value.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 124999
+
   snps,rx-thr-num-pkt-prd:
     description:
       Periodic ESS RX packet threshold count (host mode only). Set this and