CRIS: Add more delays in DDR setup

Also, make DDR latency configurable.
Signed-off-by: NJesper Nilsson <jesper.nilsson@axis.com>

arch/cris/arch-v32/mach-a3/Kconfig

@@ -33,6 +33,10 @@ config ETRAX_DDR2_CONFIG
 	hex "DDR2 config"
 	default "0"
 
+config ETRAX_DDR2_LATENCY
+	hex "DDR2 latency"
+	default "0"
+
 config ETRAX_PIO_CE0_CFG
        hex "PIO CE0 configuration"
        default "0"

arch/cris/arch-v32/mach-a3/dram_init.S

@@ -24,11 +24,21 @@
 
 	;; Refer to ddr2 MDS for initialization sequence
 
+	; 2. Wait 200us
+	move.d   10000, $r2
+1:	bne      1b
+	subq     1, $r2
+
 	; Start clock
 	move.d   REG_ADDR(ddr2, regi_ddr2_ctrl, rw_phy_cfg), $r0
 	move.d   REG_STATE(ddr2, rw_phy_cfg, en, yes), $r1
 	move.d   $r1, [$r0]
 
+	; 2. Wait 200us
+	move.d   10000, $r2
+1:	bne      1b
+	subq     1, $r2
+
 	; Reset phy and start calibration
 	move.d   REG_ADDR(ddr2, regi_ddr2_ctrl, rw_phy_ctrl), $r0
 	move.d   REG_STATE(ddr2, rw_phy_ctrl, rst, yes) | \
@@ -52,6 +62,10 @@ do_cmd:
 	lslq     16, $r1
 	or.d     $r3, $r1
 	move.d   $r1, [$r0]
+	; 2. Wait 200us
+	move.d   10000, $r4
+1:	bne      1b
+	subq     1, $r4
 	cmp.d    sdram_commands_end, $r2
 	blo      command_loop
 	nop
@@ -63,7 +77,7 @@ do_cmd:
 
 	; Set latency
 	move.d   REG_ADDR(ddr2, regi_ddr2_ctrl, rw_latency), $r0
-	move.d   0x13, $r1
+	move.d   CONFIG_ETRAX_DDR2_LATENCY, $r1
 	move.d   $r1, [$r0]
 
 	; Set configuration

arch/cris/arch-v32/mach-a3/hw_settings.S

@@ -31,6 +31,8 @@
 	; Register values
 	.dword REG_ADDR(ddr2, regi_ddr2_ctrl, rw_cfg)
 	.dword CONFIG_ETRAX_DDR2_CONFIG
+	.dword REG_ADDR(ddr2, regi_ddr2_ctrl, rw_latency)
+	.dword CONFIG_ETRAX_DDR2_LATENCY
 	.dword REG_ADDR(ddr2, regi_ddr2_ctrl, rw_timing)
 	.dword CONFIG_ETRAX_DDR2_TIMING
 	.dword CONFIG_ETRAX_DDR2_MRS