[U-Boot] [PATCH v2 3/4] usb: dwc3: add support for 16 bit UTMI+ interface

[Marek Vasut]

On 08/29/2016 02:55 AM, Kever Yang wrote:
> Hi Marek,
> 
> On 08/26/2016 05:09 PM, Marek Vasut wrote:
>> On 08/25/2016 03:17 AM, Kever Yang wrote:
>>> Hi Marek,
>>>
>>> On 08/24/2016 07:38 PM, Marek Vasut wrote:
>>>> On 08/24/2016 05:46 AM, Kever Yang wrote:
>>>>> The dwc3 controller is using 8 bit UTMI+ interface for USB2.0 PHY,
>>>>> add one variable in dwc3/dwc3_device struct to support 16 bit
>>>>> UTMI+ interface on some SoCs like Rockchip rk3399.
>>>>>
>>>>> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
>>>>> ---
>>>>>
>>>>> Changes in v2:
>>>>> - use a variable to identify utmi+ bus width instead of CONFIG MACRO
>>>>>
>>>>>    drivers/usb/dwc3/core.c |  6 ++++++
>>>>>    drivers/usb/dwc3/core.h | 12 ++++++++++++
>>>>>    include/dwc3-uboot.h    |  1 +
>>>>>    3 files changed, 19 insertions(+)
>>>>>
>>>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>>>> index 85cc96a..0613508 100644
>>>>> --- a/drivers/usb/dwc3/core.c
>>>>> +++ b/drivers/usb/dwc3/core.c
>>>>> @@ -388,6 +388,11 @@ static void dwc3_phy_setup(struct dwc3 *dwc)
>>>>>        if (dwc->dis_u2_susphy_quirk)
>>>>>            reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
>>>>>    +    if (dwc->usb2_phyif_utmi_width == 16) {
>>>>> +        reg &= ~DWC3_GUSB2PHYCFG_USBTRDTIM_MASK;
>>>>> +        reg |= DWC3_GUSB2PHYCFG_USBTRDTIM_16BIT;
>>>>> +        reg |= DWC3_GUSB2PHYCFG_PHYIF_16BIT;
>>>>> +    }
>>>> Didn't we agree to pull this info from OF ?
>>> Yes, the dwc->usb2_phyif_utmi_width is from OF,  but I make the DT parse
>>> in board file instead of in the dwc3 driver,  see my patch:
>>> [PATCH v2 2/4] board: evb-rk3399: add api to support dwc3 gadget
>> So this is basically a passing of platform data ?
> 
> Yes, this is what other platform do, I just extend one more setting.

Platform data should go away in favor of the DT probing.

>>> I think implement in this way won't affect other soc also using dwc3
>>> controller,
>>> the DT parse would cost some time which may not necessary for other soc.
>> The time needed to run the DT parsing is completely insignificant.
>> This sounds like a premature optimization.
> 
> Which way of implement this DT parse do you prefer and more reasonable,
> in dwc3 driver or in board init and dwc3 driver use it as platform data?

Driver should parse the DT.

> Thanks,
> - Kever

[...]

-- 
Best regards,
Marek Vasut