Re: [PATCH v4 2/2] usb: dwc2: add 'mode' which based on Kconfig select or dts setting

[Dinh Nguyen <dinh.linux@gmail.com>]

On 8/6/14, 5:57 PM, Paul Zimmerman wrote:
>> From: dianders@google.com [mailto:dianders@google.com] On Behalf Of Doug Anderson
>> Sent: Wednesday, August 06, 2014 3:25 PM
>>
>> On Tue, Aug 5, 2014 at 6:01 PM, Kever Yang <kever.yang@rock-chips.com> wrote:
>>> According to the "dr_mode", the otg controller can work as
>>> device role and host role. Some boards always want to use host mode
>>> and some other boards want to use gadget mode. We use the dts setting
>>> to set dwc2's mode, rather than fixing it to whatever hardware says.
>>>
>>> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
>>> Acked-by: Paul Zimmerman <paulz@synopsys.com>
>>> ---
>>>
>>> Changes in v4:
>>> - From Doug's suggestion:
>>>  -- remove dr_mode init from Kconfig code
>>>  -- change the commit meesage
>>>
>>> Changes in v3:
>>> - fix the odd spacing in dwc2_hsotg struct
>>> - From Jingoo's suggestion:
>>>     change the commit message
>>> - add dr_mode init from Kconfig
>>>
>>> Changes in v2:
>>> - put spaces around '+' operator
>>> - expand the comment for dr_mode
>>> - handle dr_mode is USB_DR_MODE_OTG
>>>
>>>  drivers/usb/dwc2/core.c     | 18 ++++++++++++++++++
>>>  drivers/usb/dwc2/core.h     |  5 +++++
>>>  drivers/usb/dwc2/platform.c |  4 ++++
>>>  3 files changed, 27 insertions(+)
>> I think this patch still makes sense even though we don't have a
>> combined driver yet.  Perhaps Paul or Dihn can confirm.
> Yes, it should be fine.
>
>> We could potentially do something based on KConfig (like you did in
>> patch set #3), but it wouldn't really make sense to do that until
>> after Dihn's work lands.
>>
>>
>>> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
>>> index 27d2c9b..738bec2 100644
>>> --- a/drivers/usb/dwc2/core.c
>>> +++ b/drivers/usb/dwc2/core.c
>>> @@ -118,6 +118,7 @@ static int dwc2_core_reset(struct dwc2_hsotg *hsotg)
>>>  {
>>>         u32 greset;
>>>         int count = 0;
>>> +       u32 gusbcfg;
>>>
>>>         dev_vdbg(hsotg->dev, "%s()\n", __func__);
>>>
>>> @@ -148,6 +149,23 @@ static int dwc2_core_reset(struct dwc2_hsotg *hsotg)
>>>                 }
>>>         } while (greset & GRSTCTL_CSFTRST);
>>>
>>> +       if (hsotg->dr_mode == USB_DR_MODE_HOST) {
>>> +               gusbcfg = readl(hsotg->regs + GUSBCFG);
>>> +               gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
>>> +               gusbcfg |= GUSBCFG_FORCEHOSTMODE;
>>> +               writel(gusbcfg, hsotg->regs + GUSBCFG);
>>> +       } else if (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL) {
>>> +               gusbcfg = readl(hsotg->regs + GUSBCFG);
>>> +               gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
>>> +               gusbcfg |= GUSBCFG_FORCEDEVMODE;
>>> +               writel(gusbcfg, hsotg->regs + GUSBCFG);
>>> +       } else if (hsotg->dr_mode == USB_DR_MODE_OTG) {
>>> +               gusbcfg = readl(hsotg->regs + GUSBCFG);
>>> +               gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
>>> +               gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
>>> +               writel(gusbcfg, hsotg->regs + GUSBCFG);
>> I think the third case here won't be too useful until the combined
>> driver, but it shouldn't hurt, right?
> Right. For the existing drivers, it shouldn't change anything, since
> nothing currently sets dr_mode. And with Kever's other patches, it
> forces host mode on the Rockchip platform, which is all that is required
> for now, if I understand correctly.
>
I managed to test this patch on the SOCFPGA platform. So

Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com>

Thanks,
DInh