On Thu, Feb 14, 2013 at 11:58:22AM +0200, Felipe Balbi wrote:
> Hi,
>
> On Thu, Feb 14, 2013 at 10:49:44AM +0100, Marc Kleine-Budde wrote:
> > >> diff --git a/drivers/usb/usb-common.c b/drivers/usb/usb-common.c
> > >> index d29503e..ad4d87d 100644
> > >> --- a/drivers/usb/usb-common.c
> > >> +++ b/drivers/usb/usb-common.c
> > >> @@ -14,6 +14,9 @@
> > >> #include <linux/kernel.h>
> > >> #include <linux/module.h>
> > >> #include <linux/usb/ch9.h>
> > >> +#include <linux/of.h>
> > >> +#include <linux/usb/of.h>
> > >> +#include <linux/usb/otg.h>
> > >>
> > >> const char *usb_speed_string(enum usb_device_speed speed)
> > >> {
> > >> @@ -32,4 +35,37 @@ const char *usb_speed_string(enum usb_device_speed speed)
> > >> }
> > >> EXPORT_SYMBOL_GPL(usb_speed_string);
> > >>
> > >> +#ifdef CONFIG_OF
> > >> +static const char *usb_dr_modes[] = {
> > >> + [USB_DR_MODE_UNKNOWN] = "",
> > >> + [USB_DR_MODE_HOST] = "host",
> > >> + [USB_DR_MODE_PERIPHERAL] = "peripheral",
> > >> + [USB_DR_MODE_OTG] = "otg",
> > >> +};
> > >
> > > It turns out this is a problem, especially since this is generic usb
> > > code: we have a chipidea controller (a patchset just arrived) that does
> > > both host and peripheral, but not otg. And I'm told now that dwc3
> > > controller can be synthesized like that too.
>
> I wonder if this part is really necessary. Usually you would read it
> from HW's registers. For dwc3, it's quite recently that we allowed the
> driver to be built with host-only, device-only or DRD functionality.
We have quite some boards on which the ID pin is not wired up, so if a
core is both host and device capable there is no way to detect the
wanted mode if not given from the devicetree.
>
> Also, this is likely to create troubles if not done correctly. Imagine
> user compiles a host-only driver and board passes dr_mode = peripheral ?
Either nothing will happen or some "you messed it up" printk should show
the user what's going on.
>
> Maybe we can ignore dr_mode in host-only and device-only builds and only
> look at it for DRD builds ?
If something is or is not compiled in the kernel this doesn't mean the kernel
is not started on boards with a different situation.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
--
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
