Re: [PATCH RFC 1/4] phy: Add new Exynos5 USB 3.0 PHY driver

[Vivek Gautam <gautamvivek1987@gmail.com>]

On Tue, Nov 5, 2013 at 5:33 PM, Jingoo Han <jg1.han@samsung.com> wrote:
> On Tuesday, November 05, 2013 8:13 PM, Jingoo Han wrote:
>> On Tuesday, November 05, 2013 6:37 PM, Kamil Debski wrote:
>> > On Tuesday, November 05, 2013 8:20 AM, Vivek Gautam wrote:
>> > > On Mon, Nov 4, 2013 at 6:42 PM, Kishon Vijay Abraham I <kishon@ti.com> wrote:
>> > > > On Monday 04 November 2013 03:45 PM, Kamil Debski wrote:
>> > > >> On Monday, November 04, 2013 7:55 AM, Kishon Vijay Abraham I wrote:
>> > > >>> On Thursday 31 October 2013 01:15 PM, Vivek Gautam wrote:
>> > > >>>>
>> > > >>>> Add a new driver for the USB 3.0 PHY on Exynos5 series of SoCs.
>> > > >>>> The new driver uses the generic PHY framework and will interact
>> > > >>>> with
>> > > >>>> DWC3 controller present on Exynos5 series of SoCs.
>> > > >>>
>> > > >>>
>> > > >>> In Exynos, you have a single IP that supports both USB3 and USB2
>> > > PHY
>> > > >>> right? I think that needs to be mentioned here.
>> > > >>
>> > > >>
>> > > >> As far as I know the IP is different.
>> > > >
>> > > >
>> > > > Ok. Sometime back Vivek was mentioning about a single IP for both
>> > > USB3
>> > > > and USB2. Thought it should be this driver. Anyway thanks for the
>> > > clarification.
>> > >
>> > > Right Kishon, I had mentioned that Exynos5's dwc3 controller have a
>> > > single IP for USB2 and USB3 phy.
>> > > From what i see, on exynos5 systems the dwc3 controller uses a combo of
>> > > usb 2 (utmi+) and usb 3 (pipe 3) phy (with base address starting
>> > > 0x12100000).
>> > >
>> > > Kamil, Tomasz,
>> > >
>> > > Please correct me if i am wrong.
>> >
>> > I have the Exynos 5250 documentation and I found two phy register ranges:
>> > 1) USB 2.0 PHY having the base address of 0x1213 0000
>> >     Chapter 33. USB 2.0 Host Controller
>> >     Subchapter 33.5.2 Phy Control Register p. 1696
>> >     First register's description is
>> >     "USB2.0 phy control register"
>> > 2) USB 3.0 PHY (I guess) with the base address 0x1210 0000
>> >     Chapter 35. USB 3.0 DRD Controller
>> >     Subchapter 35.4.6 PHY Control Register p. 1872
>> >
>> > Jingoo, could you comment on the above? You may know more than we do :)
>>
>> Hi Kamil,
>>
>> Thank you for trusting me. :-)
>> I just asked my validation engineer about 5250 USB PHY.

Thank you for clarifying this. This was really kind of you to help in
making things clear.

>> As I know, she has the best knowledge about Samsung SoC USB hardware.
>> She said that there are 2 PHY controllers such as USB 2.0 PHY, USB 3.0 PHY.
>>
>>   1) USB2.0 PHY: USB2.0 HOST, USB2.0 Device
>>   2) USB3.0 PHY: USB3.0 DRD (3.0 HOST & 3.0 Device)
>>
>> > In addition, I have a question to you Vivek - does your USB 3.0
>> > PHY support both host and device?
>>
>> According to her, USB3.0 PHY can support both 3.0 Host and 3.0 Device.
>> Thank you.
>
> In addition to this,
>
> Vivek's comment is also right. :-)
> A few minutes ago, I asked one of my USB S/W engineers.
>
> USB3.0 PHY consists of two blocks such as 3.0 block and 2.0 block.
> This USB3.0 PHY can support UTMI+ and PIPE3 interface for 3.0 block
> and 2.0 block, respectively.
>
> Conclusion:
>
>    1) USB2.0 PHY: USB2.0 HOST, USB2.0 Device
>                        Base address: 0x1213 0000
>
>    2) USB3.0 PHY: USB3.0 DRD (3.0 HOST & 3.0 Device)
>                        Base address: 0x1210 0000
>                        2.0 block(UTMI+) & 3.0 block(PIPE3)

And this is ofcourse the PHY used by DWC3 controller, which works at
both High speed as well as Super Speed.
Right ?

>
>
> Best regards,
> Jingoo Han
>



-- 
Best Regards
Vivek Gautam
Samsung R&D Institute, Bangalore
India