smsc911x: add fifo byteswap support V2

This is V2 of the smsc911x fifo byteswap patch.

The smsc911x hardware supports both big and little and endian
hardware configurations, and the linux smsc911x driver currently
detects word order.

For correct operation on big endian platforms lacking swapped
byte lanes the following patch is needed. Only fifo data is
swapped, register data does not require any swapping.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/net/smsc911x.c b/drivers/net/smsc911x.c
index eb7db032a780..5113b26fc2d9 100644
--- a/drivers/net/smsc911x.c
+++ b/drivers/net/smsc911x.c
@@ -47,6 +47,7 @@
 #include <linux/bitops.h>
 #include <linux/irq.h>
 #include <linux/io.h>
+#include <linux/swab.h>
 #include <linux/phy.h>
 #include <linux/smsc911x.h>
 #include "smsc911x.h"
@@ -175,6 +176,12 @@ static inline void
 smsc911x_tx_writefifo(struct smsc911x_data *pdata, unsigned int *buf,
                       unsigned int wordcount)
 {
+        if (pdata->config.flags & SMSC911X_SWAP_FIFO) {
+                while (wordcount--)
+                        smsc911x_reg_write(pdata, TX_DATA_FIFO, swab32(*buf++));
+                return;
+        }
+
         if (pdata->config.flags & SMSC911X_USE_32BIT) {
                 writesl(pdata->ioaddr + TX_DATA_FIFO, buf, wordcount);
                 return;
@@ -194,6 +201,12 @@ static inline void
 smsc911x_rx_readfifo(struct smsc911x_data *pdata, unsigned int *buf,
                      unsigned int wordcount)
 {
+        if (pdata->config.flags & SMSC911X_SWAP_FIFO) {
+                while (wordcount--)
+                        *buf++ = swab32(smsc911x_reg_read(pdata, RX_DATA_FIFO));
+                return;
+        }
+
         if (pdata->config.flags & SMSC911X_USE_32BIT) {
                 readsl(pdata->ioaddr + RX_DATA_FIFO, buf, wordcount);
                 return;