are USB interrupt transfers possible with s3c2410_udc?

Timo Juhani Lindfors timo.lindfors at
Fri Feb 20 08:55:37 CET 2009

[ Cc added to authors of s3c2410_udc.c ]

Andy Green <andy at> writes:
> Somebody in the thread at some point said:
> |   "USB device controller allows bulk transfer with DMA, interrupt and
> |    control transfer."
> |
> | However, the document does not mention interrupt transfers anywhere
> | else and IN_CSR2_REG, bit ISO, makes me think that maybe only bulk
> | transfers are possible:
> The docs repeatedly say that interrupt transfer is supported... but I
> don't know enough about it to know how.  I guess maybe you get further
> examining the udc driver looking for APIs around it?

I read through drivers/usb/gadget/s3c2410_udc.c but could not spot
anything obvious. arch/arm/plat-s3c24xx/include/plat/regs-udc.h
defines S3C2410_UDC_ICSR2_ISO but nothing seems to use it.

Just to have something to compare against I also read
drivers/usb/gadget/omap_udc.c which does talk about interrupt
transfers when it calls

#define OMAP_INT_EP(name,addr, maxp) \
        buf = omap_ep_setup(name "-int", addr, \
                        USB_ENDPOINT_XFER_INT, buf, maxp, 0);

which just puts the endpoint type to bmAttributes but I can't see
where that would be sent to
hardware. says "The exact endpoint
configuration is software-programmable." but does not elaborate
further what this means. Does the hardware read it from the
descriptor? Where is the descriptor sent to hardware?

best regards,
Timo  Lindfors

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