diff mbox series

[v3,1/4] dt-bindings: usb: dwc3: add reference clock period

Message ID f5ea5bc3664a98a684ad4b699a1ac610e847176f.1630389452.git.baruch@tkos.co.il
State New
Headers show
Series [v3,1/4] dt-bindings: usb: dwc3: add reference clock period | expand

Commit Message

Baruch Siach Aug. 31, 2021, 5:57 a.m. UTC
Document the snps,ref-clock-period-ns property that describes reference
clock period when it deviates from the default set value.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
v2:

Address comments from Rob Herring:

  Use standard unit suffix

  Reword description
---
 Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Felipe Balbi Aug. 31, 2021, 7:27 a.m. UTC | #1
Baruch Siach <baruch@tkos.co.il> writes:

> From: Balaji Prakash J <bjagadee@codeaurora.org>
>
> Set reference clock period when it differs from dwc3 default hardware
> set.
>
> We could calculate clock period based on reference clock frequency. But
> this information is not always available. This is the case of PCI bus
> attached USB host. For that reason we use a custom property.
>
> Tested (USB2 only) on IPQ6010 SoC based board with 24 MHz reference
> clock while hardware default is 19.2 MHz.
>
> Nacked-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Balaji Prakash J <bjagadee@codeaurora.org>
> [ baruch: rewrite commit message; drop GFLADJ code; remove 'quirk-' from
>   property name; mention tested hardware ]
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>

Acked-by: Felipe Balbi <balbi@kernel.org>
Rob Herring Sept. 1, 2021, 1:37 a.m. UTC | #2
On Tue, 31 Aug 2021 08:57:29 +0300, Baruch Siach wrote:
> Document the snps,ref-clock-period-ns property that describes reference
> clock period when it deviates from the default set value.
> 
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> ---
> v2:
> 
> Address comments from Rob Herring:
> 
>   Use standard unit suffix
> 
>   Reword description
> ---
>  Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
index 41416fbd92aa..413ac37c447f 100644
--- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
+++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
@@ -252,6 +252,14 @@  properties:
     minimum: 0
     maximum: 0x3f
 
+  snps,ref-clock-period-ns:
+    description:
+      Value for REFCLKPER field of GUCTL register for reference clock period in
+      nanoseconds, when the hardware set default does not match the actual
+      clock.
+    minimum: 1
+    maximum: 0x3ff
+
   snps,rx-thr-num-pkt-prd:
     description:
       Periodic ESS RX packet threshold count (host mode only). Set this and