usb: renesas_usbhs: add pipe/fifo link

renesas_usbhs has CFIFO which is for PIO transfer,
and D0FIFO/D1FIFO which are for DMA transfer.
The pipe selects one of these fifo when it send/recv data.
But fifo must not be selected to different pipe in same time.
This patch add pipe/fifo link for each other,
and fifo is not selected by another pipe until it is unselected.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/renesas_usbhs/pipe.c b/drivers/usb/renesas_usbhs/pipe.c
index 56137d5..c050587 100644
--- a/drivers/usb/renesas_usbhs/pipe.c
+++ b/drivers/usb/renesas_usbhs/pipe.c
@@ -562,6 +562,7 @@
 			info->bufnmb_last++;
 
 		usbhsp_flags_init(pipe);
+		pipe->fifo = NULL;
 		pipe->mod_private = NULL;
 		INIT_LIST_HEAD(&pipe->list);
 
@@ -620,6 +621,18 @@
 	return pipe;
 }
 
+void usbhs_pipe_select_fifo(struct usbhs_pipe *pipe, struct usbhs_fifo *fifo)
+{
+	if (pipe->fifo)
+		pipe->fifo->pipe = NULL;
+
+	pipe->fifo = fifo;
+
+	if (fifo)
+		fifo->pipe = pipe;
+}
+
+
 /*
  *		dcp control
  */