Re: [PATCH v3] usb: hcd: add generic PHY support

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 06/25/2014 02:32 PM, Vivek Gautam wrote:

>>  From Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

>> Add the generic PHY support, analogous to the USB PHY support. Intended it to be
>> used with the PCI EHCI/OHCI drivers and the xHCI platform driver.

>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
>> ---
>> This patch is against the 'usb-next' branch of Greg KH's 'usb.git' repo.
>> (commit id = 70d2f61fc7559df3d5be32a9d01efdb9ee1b11d8)

>> Changes in version 3:
>>   - rebased the current usb-next.
>>   - I tested this patch on my R-Car H2 USB 3.0 driver (not merged yet)

>>   drivers/usb/core/hcd.c  |   42 ++++++++++++++++++++++++++++++++++++++++--
>>   include/linux/usb/hcd.h |    3 ++-
>>   2 files changed, 42 insertions(+), 3 deletions(-)

>> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
>> index bec31e2..2841149 100644
>> --- a/drivers/usb/core/hcd.c
>> +++ b/drivers/usb/core/hcd.c
[...]
>> @@ -2649,6 +2650,29 @@ int usb_add_hcd(struct usb_hcd *hcd,
>>                  }
>>          }
>>
>> +       if (IS_ENABLED(CONFIG_GENERIC_PHY)) {
>> +               struct phy *phy = phy_get(hcd->self.controller, "usb");

> The xHCI host controller is going to have two controllers (main and
> shared) USB2 controller and
> USB3 controller. So they will have two different PHYs.

    Not necessarily -- in my case there's going be one PHY, even for xHCI.

> For example, the DWC3, which has a xHCI controller, has to have 2
> different phys -- usb2-phy and usb3-phy.

    Yes, I understood that.

> So, how the two 'hcd's' will be able to differentiate and get two separate PHYs.

    Apparently, by name? I don't see any other way...

> Unfortunately, the xHCI with DWC3 doesn't have a device node too, so
> it needs to have
> a way out to look up the PHYs (in a way suggested by Heikki :
>      usb: dwc3: host: convey the PHYs to xhci
>      (https://lkml.org/lkml/2014/6/5/585) and related patch series.
> But this also has an issue, since we need to have two separate
> constant strings to distinguish between the two PHYs,
> while creating the lookup table.

    I'm sorry, where's the issue?

> So how do you suggest me to get link the two PHYs in DWC3 with the
> XHCI host controller, the issue which i am
> facing currently while working with the patch:
> usb: host: xhci-plat: Add support to get PHYs    and the related patch
> series, since we need to handle PHY from the hcd.

    Well, I've already spoke out in another thread: you'll have to carry on 
with your approach, ignoring the patch starting this thread. I'm sorry for 
side-tracking you...

WBR, Sergei