powerpc/mpc83xx: set TXEQA/TXEQE value for mpc837XE sata

In the current u-boot code, the value of these fields are the reserved
value (0b100), through the signal integrity measurement on freescale's
board with these reserved setting, the signal eye is out of the recommended
spec for non-transition amplitude at 500mV nominal.
According to the errata for MPC8379E, we should make a change to the
recommended setting from essentially nothing at this time to 0b001 for SATA.

Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

arch/powerpc/cpu/mpc83xx/serdes.c

@@ -1,7 +1,7 @@
 /*
  * Freescale SerDes initialization routine
  *
- * Copyright (C) 2007 Freescale Semicondutor, Inc.
+ * Copyright (C) 2007,2011 Freescale Semicondutor, Inc.
  * Copyright (C) 2008 MontaVista Software, Inc.
  *
  * Author: Li Yang <leoli@freescale.com>
@@ -20,6 +20,10 @@
 /* SerDes registers */
 #define FSL_SRDSCR0_OFFS		0x0
 #define FSL_SRDSCR0_DPP_1V2		0x00008800
+#define FSL_SRDSCR0_TXEQA_MASK		0x00007000
+#define FSL_SRDSCR0_TXEQA_SATA		0x00001000
+#define FSL_SRDSCR0_TXEQE_MASK		0x00000700
+#define FSL_SRDSCR0_TXEQE_SATA		0x00000100
 #define FSL_SRDSCR1_OFFS		0x4
 #define FSL_SRDSCR1_PLLBW		0x00000040
 #define FSL_SRDSCR2_OFFS		0x8
@@ -71,6 +75,11 @@ void fsl_setup_serdes(u32 offset, char proto, u32 rfcks, char vdd)
 		tmp &= ~FSL_SRDSRSTCTL_SATA_RESET;
 		out_be32(regs + FSL_SRDSRSTCTL_OFFS, tmp);
 
+		/* Configure SRDSCR0 */
+		clrsetbits_be32(regs + FSL_SRDSCR0_OFFS,
+			FSL_SRDSCR0_TXEQA_MASK | FSL_SRDSCR0_TXEQE_MASK,
+			FSL_SRDSCR0_TXEQA_SATA | FSL_SRDSCR0_TXEQE_SATA);
+
 		/* Configure SRDSCR1 */
 		tmp = in_be32(regs + FSL_SRDSCR1_OFFS);
 		tmp &= ~FSL_SRDSCR1_PLLBW;