Hi Kishon, > -----Original Message----- > From: Kishon Vijay Abraham I [mailto:kishon@xxxxxx] > Sent: Sunday, October 11, 2015 8:11 PM > To: Punnaiah Choudary Kalluri; balbi@xxxxxx > Cc: Rob Herring; Subbaraya Sundeep Bhatta; Peter Chen; > devicetree@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; linux- > usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [RFC PATCH 1/2] usb: doc: Add bindings for ULPI platform driver > > Hi, > > On Sunday 11 October 2015 04:45 PM, punnaiah choudary kalluri wrote: > > On Wed, Sep 30, 2015 at 9:48 PM, Felipe Balbi <balbi@xxxxxx> wrote: > >> On Thu, Sep 24, 2015 at 11:18:01AM -0500, Rob Herring wrote: > >>> On Thu, Sep 24, 2015 at 4:26 AM, Subbaraya Sundeep Bhatta > >>> <subbaraya.sundeep.bhatta@xxxxxxxxxx> wrote: > >>>> Hi Peter, > >>>> > >>>>> -----Original Message----- > >>>>> From: Peter Chen [mailto:peter.chen@xxxxxxxxxxxxx] > >>>>> Sent: Thursday, September 24, 2015 2:41 PM > >>>>> To: Subbaraya Sundeep Bhatta > >>>>> Cc: balbi@xxxxxx; devicetree@xxxxxxxxxxxxxxx; kishon@xxxxxx; > >>>>> gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; linux- > >>>>> kernel@xxxxxxxxxxxxxxx; Punnaiah Choudary Kalluri; Subbaraya > >>>>> Sundeep Bhatta; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > >>>>> Subject: Re: [RFC PATCH 1/2] usb: doc: Add bindings for ULPI > >>>>> platform driver > >>>>> > >>>>> On Wed, Sep 23, 2015 at 06:24:01PM +0530, Subbaraya Sundeep > Bhatta > >>>>> wrote: > >>>>>> This patch adds binding doc info for generic ULPI PHYs platform > >>>>>> driver. > >>>>>> > >>>>>> Signed-off-by: Subbaraya Sundeep Bhatta <sbhatta@xxxxxxxxxx> > >>>>>> --- > >>>>>> .../devicetree/bindings/usb/ulpi-platform-phy.txt | 34 > >>>>> ++++++++++++++++++++ > >>>>>> 1 files changed, 34 insertions(+), 0 deletions(-) create mode > >>>>>> 100644 > >>>>>> Documentation/devicetree/bindings/usb/ulpi-platform-phy.txt > >>>>>> > >>>>>> diff --git > >>>>>> a/Documentation/devicetree/bindings/usb/ulpi-platform-phy.txt > >>>>>> b/Documentation/devicetree/bindings/usb/ulpi-platform-phy.txt > >>>>>> new file mode 100644 > >>>>>> index 0000000..7b8cbb4 > >>>>>> --- /dev/null > >>>>>> +++ b/Documentation/devicetree/bindings/usb/ulpi-platform-phy.txt > >>>>>> @@ -0,0 +1,34 @@ > >>>>>> +Platform driver for generic ULPI PHYs > >>>>>> + > >>>>>> +Required properties: > >>>>>> +- compatible : Should be "ulpi-phy" > >>>>>> +- reg : Physical base address and size of the USB > >>>>>> + controller registers map to which this PHY > >>>>>> + is connected. > >>>>>> +- view-port : Should contain viewport register offset of the > >>>>>> + USB controller to which this PHY is > >>>>>> +connected Optional > >>>>>> +properties: > >>>>>> +- drv-vbus : required if turning VBUS on/off has to be driven > >>>>>> + by writing to PHY. This feature depends on board > >>>>>> + design. > >>>>>> + > >>>>>> +Example: > >>>>>> +Below example shows the PHY binding for Chipidea USB controller > >>>>>> +which has ulpi viewport register at 0x0170 > >>>>>> + > >>>>>> + usb_phy0: phy0 { > >>>>>> + compatible = "ulpi-phy"; > >>>>>> + reg = <0xe0002000 0x1000>; > >>>>>> + view-port = <0x0170>; > >>>>>> + drv-vbus; > >>>>>> + }; > >>>>>> + > >>>>>> + usb0: usb@e0002000 { > >>>>>> + compatible = "chipidea,usb2"; > >>>>>> + interrupt-parent = <&intc>; > >>>>>> + interrupts = <0 21 4>; > >>>>>> + reg = <0xe0002000 0x1000>; > >>>>> > >>>>> Although just call devm_ioremap twice for the same register region > >>>>> does not cause any errors, I am not sure if it will has other > >>>>> potential problems. Cc: arm list. > >>>> > >>>> Yes Peter I was also in doubt to call devm_ioremap twice for same register > region. > >>>> devm_ioremap_resource complained hence modified to devm_ioremap. > >>>> Thanks for adding arm-list. > >>> > >>> Don't put overlapping resources in the DT. Having 2 drivers > >>> accessing the same registers is not a clean or safe design. > >> > >> thanks, saves me the trouble of saying the same thing. > >> > >> Bottom line, if devm_ioremap_resource() fails, you're wrong. Just fix > >> your driver and move on. > > > > Any suggestions on how to move further? > > Chipidea controller provides ulpi view port register for accessing the > > usb phy registers. Now we want to add new driver for ulpi phy > > configuration and that obviously it need of ulpi view port register > > access. So, sharing the register space between these two drivers is necessary > here. > > Why not program ULPI the same way as DWC3 does? Sorry for delay in response, back from long vacation. Can we call generic PHY phy->power_on and power_off functions to do similar function as usb2_phy->set_vbus? I assume it is to power on whole PHY chip but not to enable 5V on VBUS line. Thanks, Sundeep > > Thanks > Kishon ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
