Hi,
> On Wed, Oct 19, 2011 at 02:36:10PM +0530, Gupta, Ajay Kumar wrote:
> > Hi,
> > > On Thu, Oct 13, 2011 at 12:50:55PM +0530, Gupta, Ajay Kumar wrote:
> > > > We are facing an issue in AM335x based custom board which has two
> > > > musb port.
> > > >
> > > > a) musb0 ID pin is floating and have micro-B plug receptacle
> > > > connector. [DEVICE ONLY]
> > > > b) musb1 ID pin is grounded and have standard-A plug receptacle
> > > > connector. [HOST ONLY]
> > > >
> > > > We are using udc-core in linux v3.1-rc8 kernel. This kernel only
> > > > provides option for selecting gadget driver for first instance
> > > > only as builtin.
> > >
> > > why don't you mark all gadget drivers as modules ? I do that all the
> > > time:
> >
> > This wouldn't help if we want to use musb1 (host only) port during
> > bootup so that root file system on a pen drive connected to it can be
> mounted.
> >
> > >
> > > CONFIG_USB_GADGET=m
> > > CONFIG_USB_GADGET_DEBUG=y
> > > CONFIG_USB_GADGET_DEBUG_FILES=y
> > > CONFIG_USB_GADGET_DEBUG_FS=y
> > > CONFIG_USB_GADGET_VBUS_DRAW=2
> > > CONFIG_USB_R8A66597=m
> > > CONFIG_USB_M66592=m
> > > CONFIG_USB_AMD5536UDC=m
> > > CONFIG_USB_CI13XXX_PCI=m
> > > CONFIG_USB_NET2272=m
> > > CONFIG_USB_NET2272_DMA=y
> > > CONFIG_USB_NET2280=m
> > > CONFIG_USB_GOKU=m
> > > CONFIG_USB_EG20T=m
> > > CONFIG_USB_DUMMY_HCD=m
> > > CONFIG_USB_GADGET_DUALSPEED=y
> > > CONFIG_USB_GADGET_SUPERSPEED=y
> > > CONFIG_USB_ZERO=m
> > > CONFIG_USB_ZERO_HNPTEST=y
> > > CONFIG_USB_AUDIO=m
> > > CONFIG_USB_ETH=m
> > > CONFIG_USB_ETH_RNDIS=y
> > > CONFIG_USB_ETH_EEM=y
> > > CONFIG_USB_G_NCM=m
> > > CONFIG_USB_GADGETFS=m
> > > CONFIG_USB_FUNCTIONFS=m
> > > CONFIG_USB_FUNCTIONFS_ETH=y
> > > CONFIG_USB_FUNCTIONFS_RNDIS=y
> > > CONFIG_USB_FUNCTIONFS_GENERIC=y
> > > CONFIG_USB_FILE_STORAGE=m
> > > CONFIG_USB_FILE_STORAGE_TEST=y
> > > CONFIG_USB_MASS_STORAGE=m
> > > CONFIG_USB_G_SERIAL=m
> > > CONFIG_USB_MIDI_GADGET=m
> > > CONFIG_USB_G_PRINTER=m
> > > CONFIG_USB_CDC_COMPOSITE=m
> > > CONFIG_USB_G_NOKIA=m
> > > CONFIG_USB_G_MULTI=m
> > > CONFIG_USB_G_MULTI_RNDIS=y
> > > CONFIG_USB_G_MULTI_CDC=y
> > > CONFIG_USB_G_HID=m
> > > CONFIG_USB_G_DBGP=m
> > > # CONFIG_USB_G_DBGP_PRINTK is not set CONFIG_USB_G_DBGP_SERIAL=y
> > > CONFIG_USB_G_WEBCAM=m
> > >
> > > > Current musb driver requires a gadget module to be inserted for a
> > > > musb port to be usable in OTG mode which is the only mode
> > > > available in
> > > > v3.1-rc8 due to recent changes removing all HOST and GADGET only
> > > > ifdeffery.
> > >
> > > You can add runtime checks based on platform_data. Something like:
> > >
> > > switch (pdata->mode) {
> > > case MUSB_HOST:
> > > start_host();
> > > break;
> > > case MUSB_PERIPHERAL:
> > > start_gadget();
> > > break;
> > > case MUSB_OTG:
> > > start_gadget()
> > > start_host();
> > > break;
> > > default:
> > > error();
> > > }
> > >
> > > which means that for a port which is host-only, it won't require a
> > > gadget driver and for a port which is gadget-only, it won't start
> > > host stack.
> >
> > If so then how about the menuconfig option for gadget driver for such
> > host only port? Shouldn't the gadget driver option be unavailable for
> such ports?
>
> how we can we change menuconfig for something which isn't compile-time
> constant ?
Yes, correct. So there will be option for selecting gadget module even when
The port is host only and that would confuse the users. We would need to find
a solution for this also.
>
> > > > 3) Change musb driver so that there is no need for gadget driver
> > > > for host only ports. (may be based on musb->board_mode ?)
> > >
> > > yes.
> >
> > Doesn't seem to be a cleaner way as explained above the issue of
> > gadget Driver coming in menuconfig for such ports.
>
> you don't assign a port for a gadget driver. Ever.
Yes, agree. But wouldn't it be confusing for a host only musb port
showing gadget driver in menuconfig?
> You just load it and, as of now, it will bind to first available port.
This is fine. I have explained my concern above.
Ajay
>
> --
> balbi
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