usb: musb: make fifo support configurable

The dynamic FIFO handling under MUSB is optional, and some parts (like
the Blackfin processor) do not implement support for it.

Due to this, the FIFO reading/writing steps need special handling, so
mark the common versions weak so drivers can override.

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>
Signed-off-by: Remy Bohmer <linux@bohmer.net>

drivers/usb/musb/musb_core.c

@@ -50,6 +50,16 @@ void musb_start(void)
 #endif
 }
 
+#ifdef MUSB_NO_DYNAMIC_FIFO
+# define config_fifo(dir, idx, addr)
+#else
+# define config_fifo(dir, idx, addr) \
+	do { \
+		writeb(idx, &musbr->dir##fifosz); \
+		writew(fifoaddr >> 3, &musbr->dir##fifoadd); \
+	} while (0)
+#endif
+
 /*
  * This function configures the endpoint configuration. The musb hcd or musb
  * device implementation can use this function to configure the endpoints
@@ -74,8 +84,7 @@ void musb_configure_ep(struct musb_epinfo *epinfo, u8 cnt)
 		writeb(epinfo->epnum, &musbr->index);
 		if (epinfo->epdir) {
 			/* Configure fifo size and fifo base address */
-			writeb(idx, &musbr->txfifosz);
-			writew(fifoaddr >> 3, &musbr->txfifoadd);
+			config_fifo(tx, idx, fifoaddr);
 
 			csr = readw(&musbr->txcsr);
 #if defined(CONFIG_MUSB_HCD)
@@ -88,8 +97,7 @@ void musb_configure_ep(struct musb_epinfo *epinfo, u8 cnt)
 					&musbr->txcsr);
 		} else {
 			/* Configure fifo size and fifo base address */
-			writeb(idx, &musbr->rxfifosz);
-			writew(fifoaddr >> 3, &musbr->rxfifoadd);
+			config_fifo(rx, idx, fifoaddr);
 
 			csr = readw(&musbr->rxcsr);
 #if defined(CONFIG_MUSB_HCD)
@@ -113,6 +121,7 @@ void musb_configure_ep(struct musb_epinfo *epinfo, u8 cnt)
  * length	- number of bytes to write to FIFO
  * fifo_data	- Pointer to data buffer that contains the data to write
  */
+__attribute__((weak))
 void write_fifo(u8 ep, u32 length, void *fifo_data)
 {
 	u8  *data = (u8 *)fifo_data;
@@ -132,6 +141,7 @@ void write_fifo(u8 ep, u32 length, void *fifo_data)
  * length       - number of bytes to read from FIFO
  * fifo_data    - pointer to data buffer into which data is read
  */
+__attribute__((weak))
 void read_fifo(u8 ep, u32 length, void *fifo_data)
 {
 	u8  *data = (u8 *)fifo_data;