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? Thanks Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
