net: fec: do not access reserved register for i.MX6UL

The MIB RAM and FIFO receive start register does not exist on
i.MX6UL. Accessing these register will cause enet not work well.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Stefano Babic <sbabic@denx.de>

diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index c5dcbbbcedecf7302f0c68536c102af8aec6e77d..bff5fd111971dc7e7c50f1ae3801d8b8eefe94ce 100644 (file)
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -17,6 +17,7 @@
 
 #include <asm/arch/clock.h>
 #include <asm/arch/imx-regs.h>
+#include <asm/imx-common/sys_proto.h>
 #include <asm/io.h>
 #include <asm/errno.h>
 #include <linux/compiler.h>
@@ -551,12 +552,15 @@ static int fec_init(struct eth_device *dev, bd_t* bd)
        writel(0x00000000, &fec->eth->gaddr2);
 
 
-       /* clear MIB RAM */
-       for (i = mib_ptr; i <= mib_ptr + 0xfc; i += 4)
-               writel(0, i);
+       /* Do not access reserved register for i.MX6UL */
+       if (!is_cpu_type(MXC_CPU_MX6UL)) {
+               /* clear MIB RAM */
+               for (i = mib_ptr; i <= mib_ptr + 0xfc; i += 4)
+                       writel(0, i);
 
-       /* FIFO receive start register */
-       writel(0x520, &fec->eth->r_fstart);
+               /* FIFO receive start register */
+               writel(0x520, &fec->eth->r_fstart);
+       }
 
        /* size and address of each buffer */
        writel(FEC_MAX_PKT_SIZE, &fec->eth->emrbr);