usb: musb: setup TXCOUNT for Blackfin musb

The Blackfin implementation of musb has a TXCOUNT register that needs to
be programmed when transmitting data.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

drivers/usb/musb/musb_hcd.c

diff --git a/drivers/usb/musb/musb_hcd.c b/drivers/usb/musb/musb_hcd.c
index dd2aa7f..f14e12f 100644
--- a/drivers/usb/musb/musb_hcd.c
+++ b/drivers/usb/musb/musb_hcd.c
@@ -987,6 +987,11 @@
 			nextlen = ((len-txlen) < dev->epmaxpacketout[ep]) ?
 					(len-txlen) : dev->epmaxpacketout[ep];
 
+#ifdef CONFIG_USB_BLACKFIN
+			/* Set the transfer data size */
+			writew(nextlen, &musbr->txcount);
+#endif
+
 			/* Write the data to the FIFO */
 			write_fifo(MUSB_BULK_EP, nextlen,
 					(void *)(((u8 *)buffer) + txlen));