USB: musb: AM35x: Workaround for fifo read issue
AM35x supports only 32bit read operations so we need to have
workaround for 8bit and 16bit read operations.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/musb/am35x.c b/drivers/usb/musb/am35x.c
index 53962a0..b0aabf3 100644
--- a/drivers/usb/musb/am35x.c
+++ b/drivers/usb/musb/am35x.c
@@ -492,3 +492,33 @@
phy_on();
}
#endif
+
+/* AM35x supports only 32bit read operation */
+void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
+{
+ void __iomem *fifo = hw_ep->fifo;
+ u32 val;
+ int i;
+
+ /* Read for 32bit-aligned destination address */
+ if (likely((0x03 & (unsigned long) dst) == 0) && len >= 4) {
+ readsl(fifo, dst, len >> 2);
+ dst += len & ~0x03;
+ len &= 0x03;
+ }
+ /*
+ * Now read the remaining 1 to 3 byte or complete length if
+ * unaligned address.
+ */
+ if (len > 4) {
+ for (i = 0; i < (len >> 2); i++) {
+ *(u32 *) dst = musb_readl(fifo, 0);
+ dst += 4;
+ }
+ len &= 0x03;
+ }
+ if (len > 0) {
+ val = musb_readl(fifo, 0);
+ memcpy(dst, &val, len);
+ }
+}