Re: [PATCH 01/10] dt-bindings: usb: add support for dwc3 controller on HiSilicon SoCs

[Chen Yu <chenyu56@huawei.com>]

On 2018/12/4 0:01, Rob Herring wrote:
> On Fri, Nov 16, 2018 at 8:29 PM Chen Yu <chenyu56@huawei.com> wrote:
>>
>> Hi,
>>
>> On 2018/11/13 0:02, Rob Herring wrote:
>>> On Sat, Oct 27, 2018 at 05:58:11PM +0800, Yu Chen wrote:
>>>> This patch adds binding descriptions to support the dwc3 controller
>>>> on HiSilicon SoCs and boards like the HiKey960.
>>>>
>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>> Cc: Rob Herring <robh+dt@kernel.org>
>>>> Cc: Mark Rutland <mark.rutland@arm.com>
>>>> Cc: John Stultz <john.stultz@linaro.org>
>>>> Signed-off-by: Yu Chen <chenyu56@huawei.com>
>>>> ---
>>>>  .../devicetree/bindings/usb/dwc3-hisi.txt          | 53 ++++++++++++++++++++++
>>>>  1 file changed, 53 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/usb/dwc3-hisi.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3-hisi.txt b/Documentation/devicetree/bindings/usb/dwc3-hisi.txt
>>>> new file mode 100644
>>>> index 000000000000..e715e7b1c324
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/usb/dwc3-hisi.txt
>>>> @@ -0,0 +1,53 @@
>>>> +HiSilicon DWC3 USB SoC controller
>>>> +
>>>> +This file documents the parameters for the dwc3-hisi driver.
>>>> +
>>>> +Required properties:
>>>> +- compatible:       should be "hisilicon,hi3660-dwc3"
>>>> +- clocks:   A list of phandle + clock-specifier pairs for the
>>>> +            clocks listed in clock-names
>>>> +- clock-names:      Specify clock names
>>>> +- resets:   list of phandle and reset specifier pairs.
>>>> +
>>>> +Sub-nodes:
>>>> +The dwc3 core should be added as subnode to HiSilicon DWC3 as shown in the
>>>> +example below. The DT binding details of dwc3 can be found in:
>>>> +Documentation/devicetree/bindings/usb/dwc3.txt
>>>
>>> If you only have clocks and resets and no glue registers, then you
>>> don't need a sub-node. Just make the controller one node.
>>>
>>
>> In dwc3 glue driver，the controller driver usually probed by call of_platform_populate
>> which will search the child node of glue driver.
>> The code of function of_platform_populate is as below:
>>
>>         for_each_child_of_node(root, child) {
>>                  rc = of_platform_bus_create(child, matches, lookup, parent, true);
>>                  if (rc) {
>>                          of_node_put(child);
>>                          break;
>>                  }
>>          }
>>
>> So I think the controller node should be a sub-node.
> 
> It was done that way, but has changed. See commit fe8abf332b8f ("usb:
> dwc3: support clocks and resets for DWC3 core").

OK.Thanks!

> 
> Rob
> 
> .
>