lkml.org 
[lkml]   [2022]   [Jun]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 2/3] dt-bindings: usb: mtk-xhci: Allow middle optional clocks to be missing
From
On 19/06/2022 09:46, Chunfeng Yun wrote:
> On Fri, 2022-06-17 at 18:25 -0700, Krzysztof Kozlowski wrote:
>> On 17/06/2022 15:29, Nícolas F. R. A. Prado wrote:
>>> The current clock list in the binding doesn't allow for one of the
>>> optional clocks to be missing and a subsequent clock to be present.
>>> An
>>> example where this is an issue is in mt8192.dtsi, which has
>>> "sys_ck",
>>> "ref_ck", "xhci_ck" and would cause dtbs_check warnings.
>>>
>>> Change the clock list in a way that allows the middle optional
>>> clocks to
>>> be missing, while still guaranteeing a fixed order. The "ref_ck" is
>>> kept
>>> as a const even though it is optional for simplicity, since it is
>>> present in all current dts files.
>>>
>>> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
>>> ---
>>>
>>> .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml | 9
>>> +++++++--
>>> 1 file changed, 7 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-
>>> xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-
>>> xhci.yaml
>>> index 63cbc2b62d18..99a1b233ec90 100644
>>> --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
>>> +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
>>> @@ -80,8 +80,13 @@ properties:
>>> items:
>>> - const: sys_ck # required, the following ones are optional
>>> - const: ref_ck
>>> - - const: mcu_ck
>>> - - const: dma_ck
>>> + - enum:
>>> + - mcu_ck
>>> + - dma_ck
>>> + - xhci_ck
>>> + - enum:
>>> + - dma_ck
>>> + - xhci_ck
>>> - const: xhci_ck
>>
>> You allow now almost any order here, including incorrect like
>> sys,ref,xhci,xhci,xhci.
>>
>> The order of clocks has to be fixed and we cannot allow flexibility.
>> Are
>> you sure that these clocks are actually optional (not wired to the
>> device)?
> In fact, these optional clocks are fixed, due to no gates are provided,
> SW can't control them by CCF;
> In this case, I usually use a fixed clock, or ignore it.

But in some versions these clocks are controllable or not?

Best regards,
Krzysztof

\
 
 \ /
  Last update: 2022-06-19 14:07    [W:0.116 / U:0.244 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site