Hi,
On Sat, Jul 5, 2014 at 4:56 AM, Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:
> Hello.
>
>
> On 06/25/2014 02:32 PM, Vivek Gautam wrote:
>
>>> From Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
>
>
>>> 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@xxxxxxxxxxxxxxxxxx>
>>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>>> ---
>>> 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.
ok.
>
>
>> 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...
true, by name string only.
>
>
>> 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?
i actually thought of the phy_get() in core/hcd.c, where we would need
more than one
name string for different PHYs. But now things are clear after your explanation.
>
>
>> 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...
Thanks Sergei for clearing my doubts and the confusion.
--
Best Regards
Vivek Gautam
Samsung R&D Institute, Bangalore
India
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