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    SubjectRe: [PATCH RFC 1/4] phy: Add new Exynos5 USB 3.0 PHY driver
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    On Tue, Nov 5, 2013 at 11:06 AM, Vivek Gautam <gautamvivek1987@gmail.com> wrote:
    > Hi Tomasz,

    Sorry my mail client had some problem, so forwarding this again.

    >
    > On Nov 4, 2013 5:59 PM, "Tomasz Figa" <t.figa@samsung.com> wrote:
    >>
    >> Hi Kishon,
    >>
    >> On Monday 04 of November 2013 12:24:42 Kishon Vijay Abraham I wrote:
    >> > Hi Vivek,
    >> >
    >> > 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.
    >>
    >> Nope. There are two separate, different IPs.
    >
    > AFAICS the dwc3 controller (aka usb 3.0 drd controller, as mentioned in
    > exynos5 UM) uses a combo of usb 2 (utmi+) and usb 3 (pipe 3) phy (with base
    > address starting 0x12100000), thereby giving the driver only freedom to
    > control them as one. The entire set of registers with base 0x12100000 for
    > exynos5250 and later 0x12500000 for exynos5420 are being programmed by this
    > driver. That's the reason i structured the driver this way, and thereby it
    > makes the dwc3 controller to just use only single phy.
    > Please correct me if i am wrong.
    >
    >>
    >> > Do you have separate registers that should be used for
    >> > initializing/powerin_on/powering_off etc.. for usb2 phy and usb3 phy? If
    >> > so, then you should model this driver as a single driver that supports
    >> > two PHYs similar to what Sylwester has done before?
    >>
    >> Sylwester's MIPI PHY uses such model because it has a single register
    >> that controls both PHYs.
    >>
    >> Best regards,
    >> Tomasz
    >>
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    --
    Best Regards
    Vivek Gautam
    Samsung R&D Institute, Bangalore
    India


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