Am Samstag, 4. Januar 2014, 12:06:22 schrieb Apelete Seketeli: > On 04-Jan-14, Richard Weinberger wrote: > > On Thu, Dec 19, 2013 at 9:42 PM, Apelete Seketeli <apelete@xxxxxxxxxxxx> wrote: > > > Add support for Ingenic JZ4740 USB Device Controller through a > > > specific musb glue layer. > > > > > > JZ4740 UDC not being OTG compatible and missing some hardware > > > registers, this musb glue layer is written from scratch to be used in > > > gadget mode only and take silicon design specifics into account. > > > > > > Signed-off-by: Apelete Seketeli <apelete@xxxxxxxxxxxx> > > > Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> > > > --- > > > > > > drivers/usb/musb/Kconfig | 8 +- > > > drivers/usb/musb/Makefile | 1 + > > > drivers/usb/musb/jz4740.c | 201 > > > +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 209 > > > insertions(+), 1 deletion(-) > > > create mode 100644 drivers/usb/musb/jz4740.c > > > > > > diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig > > > index 57dfc0c..14d7e72 100644 > > > --- a/drivers/usb/musb/Kconfig > > > +++ b/drivers/usb/musb/Kconfig > > > @@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN > > > > > > config USB_MUSB_UX500 > > > > > > tristate "Ux500 platforms" > > > > > > +config USB_MUSB_JZ4740 > > > + tristate "JZ4740" > > > + depends on MACH_JZ4740 || COMPILE_TEST > > > + depends on USB_MUSB_GADGET > > > + depends on USB_OTG_BLACKLIST_HUB > > > + > > > > > > endchoice > > > > > > config USB_MUSB_AM335X_CHILD > > > > > > @@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD > > > > > > choice > > > > > > prompt 'MUSB DMA mode' > > > > > > - default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM > > > + default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740 > > > > Just out of curiosity, why can't we use DMA? > > We wrote the musb glue layer for the Ben Nanonote handheld computer > only to provide ethernet-over-usb functionality. > > I was thinking about adding DMA support later, but Lars-Peter Clausen > did experiment with DMA, and found out that all ethernet packets were > unaligned, while the DMA only works if they are aligned. > As a consequence, the DMA was bypassed all the time, making it useless > at least for the ethernet gadget we are interested in. > > That's why DMA didn't make it into the glue layer. DMA support would be nice to have. Especially to make the USB storage gadget work well with the Ben NanoNote. Thanks, //richard -- 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
