[U-Boot] [PATCH 1/2] PPC4xx IBM Memory Controller DDR autocalibration routines.

Adam Graham agraham at amcc.com
Wed Sep 3 21:26:28 CEST 2008


Alternate SDRAM DDR autocalibration routine that can be generically used
for any PPC4xx chips that have the IBM SDRAM Controller core allowing for
support of more DIMM/memory chip vendors and gets the DDR autocalibration
values which give the best read latency performance (SDRAM0_RDCC.[RDSS]).

Two alternate SDRAM DDR autocalibration algoritm are provided in this patch,
"Method_A" and "Method_B".  DDR autocalibration Method_A scans the full range
of possible PPC4xx  SDRAM Controller DDR autocalibration values and takes a
lot longer to run than Method_B.  Method_B executes in the same amount of time
as the currently existing DDR autocalibration routine, i.e. 1 second or so.
Normally Method_B is used and it is set as the default method.

The current U-Boot PPC4xx DDR autocalibration code calibrates the IBM SDRAM
Controller registers.[bit-field]:
1)  SDRAM0_RQDC.[RQFD]
2)  SDRAM0_RFDC.[RFFD]

This alternate PPC4xx DDR autocalibration code calibrates the following
IBM SDRAM Controller registers.[bit-field]:

1)  SDRAM0_WRDTR.[WDTR]
2)  SDRAM0_CLKTR.[CKTR]
3)  SDRAM0_RQDC.[RQFD]
4)  SDRAM0_RFDC.[RFFD]

and will also use the calibrated settings of the above four registers that
produce the best "Read Sample Cycle Select" value in the SDRAM0_RDCC.[RDSS]
register.[bit-field].

Signed-off-by: Adam Graham <agraham at amcc.com>
---
 cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c | 1212 +++++++++++++++++++++++++++++++++++
 1 files changed, 1212 insertions(+), 0 deletions(-)
 create mode 100644 cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c

diff --git a/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c b/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c
new file mode 100644
index 0000000..83b9883
--- /dev/null
+++ b/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c
@@ -0,0 +1,1212 @@
+/*
+ * cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c
+ * This SPD SDRAM detection code supports AMCC PPC44x cpu's with a
+ * DDR2 controller (non Denali Core). Those currently are:
+ *
+ * 405:		405EX
+ * 440/460:	440SP/440SPe/460EX/460GT/460SX
+ *
+ * (C) Copyright 2008 Applied Micro Circuits Corporation
+ * Adam Graham  <agraham at amcc.com>
+ *
+ * (C) Copyright 2007-2008
+ * Stefan Roese, DENX Software Engineering, sr at denx.de.
+ *
+ * COPYRIGHT   AMCC   CORPORATION 2004
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/* define DEBUG for debugging output (obviously ;-)) */
+#undef DEBUG
+
+#include <common.h>
+#include <ppc4xx.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+
+#if defined(CONFIG_PPC4xx_DDR_AUTOCALIBRATION)
+
+/*
+ * Only compile the DDR auto-calibration code for NOR boot and
+ * not for NAND boot (NAND SPL and NAND U-Boot - NUB)
+ */
+#if !defined(CONFIG_NAND_U_BOOT) && !defined(CONFIG_NAND_SPL)
+
+#define MAXBXCF			4
+#define SDRAM_RXBAS_SHIFT_1M	20
+
+#if defined(CFG_DECREMENT_PATTERNS)
+#define NUMMEMTESTS		24
+#else
+#define NUMMEMTESTS		8
+#endif /* CFG_DECREMENT_PATTERNS */
+#define NUMLOOPS		1	/* configure as you deem approporiate */
+#define NUMMEMWORDS		16
+
+/* Private Structure Definitions */
+
+struct autocal_regs {
+	u32 rffd;
+	u32 rqfd;
+};
+
+struct ddrautocal {
+	u32 rffd;
+	u32 rffd_min;
+	u32 rffd_max;
+	u32 rffd_size;
+	u32 rqfd;
+	u32 rqfd_size;
+	u32 rdcc;
+	u32 flags;
+};
+
+struct sdram_timing {
+	u32 wrdtr;
+	u32 clktr;
+};
+
+struct sdram_timing_clks {
+	u32 wrdtr;
+	u32 clktr;
+	u32 rdcc;
+	u32 flags;
+};
+
+struct autocal_clks {
+	struct sdram_timing_clks clocks;
+	struct ddrautocal	 autocal;
+};
+
+/*--------------------------------------------------------------------------+
+ * Prototypes
+ *--------------------------------------------------------------------------*/
+#if defined(CONFIG_PPC4xx_DDR_METHOD_A)
+static u32 DQS_calibration_methodA(struct ddrautocal *);
+static u32 program_DQS_calibration_methodA(struct ddrautocal *);
+#else
+static u32 DQS_calibration_methodB(struct ddrautocal *);
+static u32 program_DQS_calibration_methodB(struct ddrautocal *);
+#endif
+static int short_mem_test(u32 *);
+
+/*
+ * To provide an interface for board specific config values in this common
+ * DDR setup code, we implement he "weak" default functions here. They return
+ * the default value back to the caller.
+ *
+ * Please see include/configs/yucca.h for an example fora board specific
+ * implementation.
+ */
+
+#if !defined(CONFIG_SPD_EEPROM)
+u32 __ddr_wrdtr(u32 default_val)
+{
+	return default_val;
+}
+u32 ddr_wrdtr(u32) __attribute__((weak, alias("__ddr_wrdtr")));
+
+u32 __ddr_clktr(u32 default_val)
+{
+	return default_val;
+}
+u32 ddr_clktr(u32) __attribute__((weak, alias("__ddr_clktr")));
+
+/*
+ * Board-specific Platform code can reimplement spd_ddr_init_hang () if needed
+ */
+void __spd_ddr_init_hang(void)
+{
+	hang();
+}
+void
+spd_ddr_init_hang(void) __attribute__((weak, alias("__spd_ddr_init_hang")));
+#endif /* defined(CONFIG_SPD_EEPROM) */
+
+ulong __ddr_scan_option(ulong default_val)
+{
+	return default_val;
+}
+ulong ddr_scan_option(ulong) __attribute__((weak, alias("__ddr_scan_option")));
+
+static u32 *get_membase(int bxcr_num)
+{
+	ulong bxcf;
+	u32 *membase;
+
+#if defined(SDRAM_R0BAS)
+	/* BAS from Memory Queue rank reg. */
+	membase =
+	    (u32 *)(SDRAM_RXBAS_SDBA_DECODE(mfdcr_any(SDRAM_R0BAS+bxcr_num)));
+	bxcf = 0;	/* just to satisfy the compiler */
+#else
+	/* BAS from SDRAM_MBxCF mem rank reg. */
+	mfsdram(SDRAM_MB0CF + (bxcr_num<<2), bxcf);
+	membase = (u32 *)((bxcf & 0xfff80000) << 3);
+#endif
+
+	return membase;
+}
+
+static inline void ecc_clear_status_reg(void)
+{
+	mtsdram(SDRAM_ECCCR, 0xffffffff);
+#if defined(SDRAM_R0BAS)
+	mtdcr(SDRAM_ERRSTATLL, 0xffffffff);
+#endif
+}
+
+static int ecc_check_status_reg(void)
+{
+	u32 ecc_status;
+
+	/*
+	 * Compare suceeded, now check
+	 * if got ecc error. If got an
+	 * ecc error, then don't count
+	 * this as a passing value
+	 */
+	mfsdram(SDRAM_ECCCR, ecc_status);
+	if (ecc_status != 0x00000000) {
+		/* clear on error */
+		ecc_clear_status_reg();
+		/* ecc check failure */
+		return 0;
+	}
+	ecc_clear_status_reg();
+	sync();
+
+	return 1;
+}
+
+/* return 1 if passes, 0 if fail */
+static int short_mem_test(u32 *base_address)
+{
+	int i, j, l;
+	u32 ecc_mode = 0;
+
+	ulong test[NUMMEMTESTS][NUMMEMWORDS] = {
+	/* 0 */	{0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+		 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+		 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+		 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF},
+	/* 1 */	{0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+		 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+		 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+		 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000},
+	/* 2 */	{0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+		 0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+		 0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+		 0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555},
+	/* 3 */	{0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+		 0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+		 0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+		 0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA},
+	/* 4 */	{0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+		 0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+		 0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+		 0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A},
+	/* 5 */	{0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+		 0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+		 0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+		 0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5},
+	/* 6 */	{0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+		 0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+		 0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+		 0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA},
+	/* 7 */	{0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55,
+		 0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55,
+		 0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55,
+		 0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55},
+
+#if defined(CFG_DECREMENT_PATTERNS)
+	/* 8 */	{0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
+		 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
+		 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
+		 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff},
+	/* 9 */	{0xfffefffe, 0xfffefffe, 0xfffefffe, 0xfffefffe,
+		 0xfffefffe, 0xfffefffe, 0xfffefffe, 0xfffefffe,
+		 0xfffefffe, 0xfffefffe, 0xfffefffe, 0xfffefffe,
+		 0xfffefffe, 0xfffefffe, 0xfffefffe, 0xfffefffe},
+	/* 10 */{0xfffdfffd, 0xfffdfffd, 0xfffdffff, 0xfffdfffd,
+		 0xfffdfffd, 0xfffdfffd, 0xfffdffff, 0xfffdfffd,
+		 0xfffdfffd, 0xfffdfffd, 0xfffdffff, 0xfffdfffd,
+		 0xfffdfffd, 0xfffdfffd, 0xfffdffff, 0xfffdfffd},
+	/* 11 */{0xfffcfffc, 0xfffcfffc, 0xfffcfffc, 0xfffcfffc,
+		 0xfffcfffc, 0xfffcfffc, 0xfffcfffc, 0xfffcfffc,
+		 0xfffcfffc, 0xfffcfffc, 0xfffcfffc, 0xfffcfffc,
+		 0xfffcfffc, 0xfffcfffc, 0xfffcfffc, 0xfffcfffc},
+	/* 12 */{0xfffbfffb, 0xfffffffb, 0xfffffffb, 0xfffffffb,
+		 0xfffbfffb, 0xfffffffb, 0xfffffffb, 0xfffffffb,
+		 0xfffbfffb, 0xfffffffb, 0xfffffffb, 0xfffffffb,
+		 0xfffbfffb, 0xfffffffb, 0xfffffffb, 0xfffffffb},
+	/* 13 */{0xfffafffa, 0xfffafffa, 0xfffffffa, 0xfffafffa,
+		 0xfffafffa, 0xfffafffa, 0xfffafffa, 0xfffafffa,
+		 0xfffafffa, 0xfffafffa, 0xfffafffa, 0xfffafffa,
+		 0xfffafffa, 0xfffafffa, 0xfffafffa, 0xfffafffa},
+	/* 14 */{0xfff9fff9, 0xfff9fff9, 0xfff9fff9, 0xfff9fff9,
+		 0xfff9fff9, 0xfff9fff9, 0xfff9fff9, 0xfff9fff9,
+		 0xfff9fff9, 0xfff9fff9, 0xfff9fff9, 0xfff9fff9,
+		 0xfff9fff9, 0xfff9fff9, 0xfff9fff9, 0xfff9fff9},
+	/* 15 */{0xfff8fff8, 0xfff8fff8, 0xfff8fff8, 0xfff8fff8,
+		 0xfff8fff8, 0xfff8fff8, 0xfff8fff8, 0xfff8fff8,
+		 0xfff8fff8, 0xfff8fff8, 0xfff8fff8, 0xfff8fff8,
+		 0xfff8fff8, 0xfff8fff8, 0xfff8fff8, 0xfff8fff8},
+	/* 16 */{0xfff7fff7, 0xfff7ffff, 0xfff7fff7, 0xfff7fff7,
+		 0xfff7fff7, 0xfff7ffff, 0xfff7fff7, 0xfff7fff7,
+		 0xfff7fff7, 0xfff7ffff, 0xfff7fff7, 0xfff7fff7,
+		 0xfff7ffff, 0xfff7ffff, 0xfff7fff7, 0xfff7fff7},
+	/* 17 */{0xfff6fff5, 0xfff6ffff, 0xfff6fff6, 0xfff6fff7,
+		 0xfff6fff5, 0xfff6ffff, 0xfff6fff6, 0xfff6fff7,
+		 0xfff6fff5, 0xfff6ffff, 0xfff6fff6, 0xfff6fff7,
+		 0xfff6fff5, 0xfff6ffff, 0xfff6fff6, 0xfff6fff7},
+	/* 18 */{0xfff5fff4, 0xfff5ffff, 0xfff5fff5, 0xfff5fff5,
+		 0xfff5fff4, 0xfff5ffff, 0xfff5fff5, 0xfff5fff5,
+		 0xfff5fff4, 0xfff5ffff, 0xfff5fff5, 0xfff5fff5,
+		 0xfff5fff4, 0xfff5ffff, 0xfff5fff5, 0xfff5fff5},
+	/* 19 */{0xfff4fff3, 0xfff4ffff, 0xfff4fff4, 0xfff4fff4,
+		 0xfff4fff3, 0xfff4ffff, 0xfff4fff4, 0xfff4fff4,
+		 0xfff4fff3, 0xfff4ffff, 0xfff4fff4, 0xfff4fff4,
+		 0xfff4fff3, 0xfff4ffff, 0xfff4fff4, 0xfff4fff4},
+	/* 20 */{0xfff3fff2, 0xfff3ffff, 0xfff3fff3, 0xfff3fff3,
+		 0xfff3fff2, 0xfff3ffff, 0xfff3fff3, 0xfff3fff3,
+		 0xfff3fff2, 0xfff3ffff, 0xfff3fff3, 0xfff3fff3,
+		 0xfff3fff2, 0xfff3ffff, 0xfff3fff3, 0xfff3fff3},
+	/* 21 */{0xfff2ffff, 0xfff2ffff, 0xfff2fff2, 0xfff2fff2,
+		 0xfff2ffff, 0xfff2ffff, 0xfff2fff2, 0xfff2fff2,
+		 0xfff2ffff, 0xfff2ffff, 0xfff2fff2, 0xfff2fff2,
+		 0xfff2ffff, 0xfff2ffff, 0xfff2fff2, 0xfff2fff2},
+	/* 22 */{0xfff1ffff, 0xfff1ffff, 0xfff1fff1, 0xfff1fff1,
+		 0xfff1ffff, 0xfff1ffff, 0xfff1fff1, 0xfff1fff1,
+		 0xfff1ffff, 0xfff1ffff, 0xfff1fff1, 0xfff1fff1,
+		 0xfff1ffff, 0xfff1ffff, 0xfff1fff1, 0xfff1fff1},
+	/* 23 */{0xfff0fff0, 0xfff0fff0, 0xfff0fff0, 0xfff0fff0,
+		 0xfff0fff0, 0xfff0fff0, 0xfff0fff0, 0xfff0fff0,
+		 0xfff0fff0, 0xfff0fff0, 0xfff0fff0, 0xfff0fff0,
+		 0xfff0fff0, 0xfff0fffe, 0xfff0fff0, 0xfff0fff0},
+#endif /* CFG_DECREMENT_PATTERNS */
+								 };
+
+	mfsdram(SDRAM_MCOPT1, ecc_mode);
+	if ((ecc_mode & SDRAM_MCOPT1_MCHK_CHK_REP) ==
+						SDRAM_MCOPT1_MCHK_CHK_REP) {
+		ecc_clear_status_reg();
+		sync();
+		ecc_mode = 1;
+	} else {
+		ecc_mode = 0;
+	}
+
+	/*
+	 * Run the short memory test.
+	 */
+	for (i = 0; i < NUMMEMTESTS; i++) {
+		for (j = 0; j < NUMMEMWORDS; j++) {
+			base_address[j] = test[i][j];
+			ppcDcbf((ulong)&(base_address[j]));
+		}
+		sync();
+		for (l = 0; l < NUMLOOPS; l++) {
+			for (j = 0; j < NUMMEMWORDS; j++) {
+				if (base_address[j] != test[i][j]) {
+					ppcDcbf((u32)&(base_address[j]));
+					return 0;
+				} else {
+					if (ecc_mode) {
+						if (!ecc_check_status_reg())
+							return 0;
+					}
+				}
+				ppcDcbf((u32)&(base_address[j]));
+			} /* for (j = 0; j < NUMMEMWORDS; j++) */
+			sync();
+		} /* for (l=0; l<NUMLOOPS; l++) */
+	}
+
+	return 1;
+}
+
+#if defined(CONFIG_PPC4xx_DDR_METHOD_A)
+/*-----------------------------------------------------------------------------+
+| program_DQS_calibration_methodA.
++-----------------------------------------------------------------------------*/
+static u32 program_DQS_calibration_methodA(struct ddrautocal *ddrcal)
+{
+	u32 pass_result = 0;
+
+#ifdef DEBUG
+	ulong temp;
+
+	mfsdram(SDRAM_RDCC, temp);
+	debug("<%s>SDRAM_RDCC=0x%08x\n", __func__, temp);
+#endif
+
+	pass_result = DQS_calibration_methodA(ddrcal);
+
+	return pass_result;
+}
+
+/*
+ * DQS_calibration_methodA()
+ *
+ * Autocalibration Method A
+ *
+ *  ARRAY [Entire DQS Range] DQS_Valid_Window ;    initialized to all zeros
+ *  ARRAY [Entire FDBK Range] FDBK_Valid_Window;   initialized to all zeros
+ *  MEMWRITE(addr, expected_data);
+ *  for (i = 0; i < Entire DQS Range; i++) {       RQDC.RQFD
+ *      for (j = 0; j < Entire FDBK Range; j++) {  RFDC.RFFD
+ *         MEMREAD(addr, actual_data);
+ *         if (actual_data == expected_data) {
+ *             DQS_Valid_Window[i] = 1;            RQDC.RQFD
+ *             FDBK_Valid_Window[i][j] = 1;        RFDC.RFFD
+ *         }
+ *      }
+ *  }
+ */
+static u32 DQS_calibration_methodA(struct ddrautocal *cal)
+{
+	ulong rfdc_reg;
+	ulong rffd;
+
+	ulong rqdc_reg;
+	ulong rqfd;
+
+	u32 *membase;
+	ulong bxcf;
+	int rqfd_average;
+	int bxcr_num;
+	int rffd_average;
+	int pass;
+	u32 passed = 0;
+
+	int in_window;
+	struct autocal_regs curr_win_min;
+	struct autocal_regs curr_win_max;
+	struct autocal_regs best_win_min;
+	struct autocal_regs best_win_max;
+	struct autocal_regs loop_win_min;
+	struct autocal_regs loop_win_max;
+
+#ifdef DEBUG
+	ulong temp;
+#endif
+	ulong rdcc;
+
+	char slash[] = "\\|/-\\|/-";
+	int loopi = 0;
+
+	/* start */
+	in_window = 0;
+
+	memset(&curr_win_min, 0, sizeof(curr_win_min));
+	memset(&curr_win_max, 0, sizeof(curr_win_max));
+	memset(&best_win_min, 0, sizeof(best_win_min));
+	memset(&best_win_max, 0, sizeof(best_win_max));
+	memset(&loop_win_min, 0, sizeof(loop_win_min));
+	memset(&loop_win_max, 0, sizeof(loop_win_max));
+
+	rdcc = 0;
+
+	/*
+	 * Program RDCC register
+	 * Read sample cycle auto-update enable
+	 */
+	mtsdram(SDRAM_RDCC, SDRAM_RDCC_RDSS_T1 | SDRAM_RDCC_RSAE_ENABLE);
+
+#ifdef DEBUG
+	mfsdram(SDRAM_RDCC, temp);
+	debug("<%s>SDRAM_RDCC=0x%x\n", __func__, temp);
+	mfsdram(SDRAM_RTSR, temp);
+	debug("<%s>SDRAM_RTSR=0x%x\n", __func__, temp);
+	mfsdram(SDRAM_FCSR, temp);
+	debug("<%s>SDRAM_FCSR=0x%x\n", __func__, temp);
+#endif
+
+	/*
+	 * Program RQDC register
+	 * Internal DQS delay mechanism enable
+	 */
+	mtsdram(SDRAM_RQDC,
+		SDRAM_RQDC_RQDE_ENABLE | SDRAM_RQDC_RQFD_ENCODE(0x00));
+
+#ifdef DEBUG
+	mfsdram(SDRAM_RQDC, temp);
+	debug("<%s>SDRAM_RQDC=0x%x\n", __func__, temp);
+#endif
+
+	/*
+	 * Program RFDC register
+	 * Set Feedback Fractional Oversample
+	 * Auto-detect read sample cycle enable
+	 */
+	mtsdram(SDRAM_RFDC, SDRAM_RFDC_ARSE_ENABLE |
+		SDRAM_RFDC_RFOS_ENCODE(0) | SDRAM_RFDC_RFFD_ENCODE(0));
+
+#ifdef DEBUG
+	mfsdram(SDRAM_RFDC, temp);
+	debug("<%s>SDRAM_RFDC=0x%x\n", __func__, temp);
+#endif
+
+	putc(' ');
+	for (rqfd = 0; rqfd <= SDRAM_RQDC_RQFD_MAX; rqfd++) {
+
+		mfsdram(SDRAM_RQDC, rqdc_reg);
+		rqdc_reg &= ~(SDRAM_RQDC_RQFD_MASK);
+		mtsdram(SDRAM_RQDC, rqdc_reg | SDRAM_RQDC_RQFD_ENCODE(rqfd));
+
+		putc('\b');
+		putc(slash[loopi++ % 8]);
+
+		curr_win_min.rffd = 0;
+		curr_win_max.rffd = 0;
+		in_window = 0;
+
+		for (rffd = 0, pass = 0; rffd <= SDRAM_RFDC_RFFD_MAX; rffd++) {
+			mfsdram(SDRAM_RFDC, rfdc_reg);
+			rfdc_reg &= ~(SDRAM_RFDC_RFFD_MASK);
+			mtsdram(SDRAM_RFDC,
+				    rfdc_reg | SDRAM_RFDC_RFFD_ENCODE(rffd));
+
+			for (bxcr_num = 0; bxcr_num < MAXBXCF; bxcr_num++) {
+				mfsdram(SDRAM_MB0CF + (bxcr_num<<2), bxcf);
+
+				/* Banks enabled */
+				if (bxcf & SDRAM_BXCF_M_BE_MASK) {
+					/* Bank is enabled */
+					membase = get_membase(bxcr_num);
+					pass = short_mem_test(membase);
+				} /* if bank enabled */
+			} /* for bxcr_num */
+
+			/* If this value passed update RFFD windows */
+			if (pass && !in_window) { /* at the start of window */
+				in_window = 1;
+				curr_win_min.rffd = curr_win_max.rffd = rffd;
+				curr_win_min.rqfd = curr_win_max.rqfd = rqfd;
+				mfsdram(SDRAM_RDCC, rdcc); /*record this value*/
+			} else if (!pass && in_window) { /* at end of window */
+				in_window = 0;
+			} else if (pass && in_window) { /* within the window */
+				curr_win_max.rffd = rffd;
+				curr_win_max.rqfd = rqfd;
+			}
+			/* else if (!pass && !in_window)
+				skip - no pass, not currently in a window */
+
+			if (in_window) {
+				if ((curr_win_max.rffd - curr_win_min.rffd) >
+				    (best_win_max.rffd - best_win_min.rffd)) {
+					best_win_min.rffd = curr_win_min.rffd;
+					best_win_max.rffd = curr_win_max.rffd;
+
+					best_win_min.rqfd = curr_win_min.rqfd;
+					best_win_max.rqfd = curr_win_max.rqfd;
+					cal->rdcc	  = rdcc;
+				}
+				passed = 1;
+			}
+		} /* RFDC.RFFD */
+
+		/*
+		 * save-off the best window results of the RFDC.RFFD
+		 * for this RQDC.RQFD setting
+		 */
+		/*
+		 * if (just ended RFDC.RFDC loop pass window) >
+		 *	(prior RFDC.RFFD loop pass window)
+		 */
+		if ((best_win_max.rffd - best_win_min.rffd) >
+		    (loop_win_max.rffd - loop_win_min.rffd)) {
+			loop_win_min.rffd = best_win_min.rffd;
+			loop_win_max.rffd = best_win_max.rffd;
+			loop_win_min.rqfd = rqfd;
+			loop_win_max.rqfd = rqfd;
+			debug("RQFD.min 0x%08x, RQFD.max 0x%08x, "
+			      "RFFD.min 0x%08x, RFFD.max 0x%08x\n",
+					loop_win_min.rqfd, loop_win_max.rqfd,
+					loop_win_min.rffd, loop_win_max.rffd);
+		}
+	} /* RQDC.RQFD */
+
+	putc('\b');
+
+	debug("\n");
+
+	if ((loop_win_min.rffd == 0) && (loop_win_max.rffd == 0) &&
+	    (best_win_min.rffd == 0) && (best_win_max.rffd == 0) &&
+	    (best_win_min.rqfd == 0) && (best_win_max.rqfd == 0)) {
+		passed = 0;
+	}
+
+	/*
+	 * Need to program RQDC before RFDC.
+	 */
+	debug("<%s> RQFD Min: 0x%x\n", __func__, loop_win_min.rqfd);
+	debug("<%s> RQFD Max: 0x%x\n", __func__, loop_win_max.rqfd);
+	rqfd_average = loop_win_max.rqfd;
+
+	if (rqfd_average < 0)
+		rqfd_average = 0;
+
+	if (rqfd_average > SDRAM_RQDC_RQFD_MAX)
+		rqfd_average = SDRAM_RQDC_RQFD_MAX;
+
+	debug("<%s> RFFD average: 0x%08x\n", __func__, rqfd_average);
+	mtsdram(SDRAM_RQDC, (rqdc_reg & ~SDRAM_RQDC_RQFD_MASK) |
+				SDRAM_RQDC_RQFD_ENCODE(rqfd_average));
+
+	debug("<%s> RFFD Min: 0x%08x\n", __func__, loop_win_min.rffd);
+	debug("<%s> RFFD Max: 0x%08x\n", __func__, loop_win_max.rffd);
+	rffd_average = ((loop_win_min.rffd + loop_win_max.rffd) / 2);
+
+	if (rffd_average < 0)
+		rffd_average = 0;
+
+	if (rffd_average > SDRAM_RFDC_RFFD_MAX)
+		rffd_average = SDRAM_RFDC_RFFD_MAX;
+
+	debug("<%s> RFFD average: 0x%08x\n", __func__, rffd_average);
+	mtsdram(SDRAM_RFDC, rfdc_reg | SDRAM_RFDC_RFFD_ENCODE(rffd_average));
+
+	/* if something passed, then return the size of the largest window */
+	if (passed != 0) {
+		passed		= loop_win_max.rffd - loop_win_min.rffd;
+		cal->rqfd	= rqfd_average;
+		cal->rffd	= rffd_average;
+		cal->rffd_min	= loop_win_min.rffd;
+		cal->rffd_max	= loop_win_max.rffd;
+	}
+
+	return (u32)passed;
+}
+
+#else	/* !defined(CONFIG_PPC4xx_DDR_METHOD_A) */
+
+/*-----------------------------------------------------------------------------+
+| program_DQS_calibration_methodB.
++-----------------------------------------------------------------------------*/
+static u32 program_DQS_calibration_methodB(struct ddrautocal *ddrcal)
+{
+	u32 pass_result = 0;
+
+#ifdef DEBUG
+	ulong temp;
+#endif
+
+	/*
+	 * Program RDCC register
+	 * Read sample cycle auto-update enable
+	 */
+	mtsdram(SDRAM_RDCC, SDRAM_RDCC_RDSS_T2 | SDRAM_RDCC_RSAE_ENABLE);
+
+#ifdef DEBUG
+	mfsdram(SDRAM_RDCC, temp);
+	debug("<%s>SDRAM_RDCC=0x%08x\n", __func__, temp);
+#endif
+
+	/*
+	 * Program RQDC register
+	 * Internal DQS delay mechanism enable
+	 */
+	mtsdram(SDRAM_RQDC,
+#if defined(CONFIG_DDR_RQDC_START_VAL)
+			SDRAM_RQDC_RQDE_ENABLE |
+			    SDRAM_RQDC_RQFD_ENCODE(CONFIG_DDR_RQDC_START_VAL));
+#else
+			SDRAM_RQDC_RQDE_ENABLE | SDRAM_RQDC_RQFD_ENCODE(0x38));
+#endif
+
+#ifdef DEBUG
+	mfsdram(SDRAM_RQDC, temp);
+	debug("<%s>SDRAM_RQDC=0x%08x\n", __func__, temp);
+#endif
+
+	/*
+	 * Program RFDC register
+	 * Set Feedback Fractional Oversample
+	 * Auto-detect read sample cycle enable
+	 */
+	mtsdram(SDRAM_RFDC,	SDRAM_RFDC_ARSE_ENABLE |
+				SDRAM_RFDC_RFOS_ENCODE(0) |
+				SDRAM_RFDC_RFFD_ENCODE(0));
+
+#ifdef DEBUG
+	mfsdram(SDRAM_RFDC, temp);
+	debug("<%s>SDRAM_RFDC=0x%08x\n", __func__, temp);
+#endif
+
+	pass_result = DQS_calibration_methodB(ddrcal);
+
+	return pass_result;
+}
+
+/*
+ * DQS_calibration_methodB()
+ *
+ * Autocalibration Method B
+ *
+ * ARRAY [Entire DQS Range] DQS_Valid_Window ;       initialized to all zeros
+ * ARRAY [Entire Feedback Range] FDBK_Valid_Window;  initialized to all zeros
+ * MEMWRITE(addr, expected_data);
+ * Initialialize the DQS delay to 80 degrees (MCIF0_RRQDC[RQFD]=0x38).
+ *
+ *  for (j = 0; j < Entire Feedback Range; j++) {
+ *      MEMREAD(addr, actual_data);
+ *       if (actual_data == expected_data) {
+ *           FDBK_Valid_Window[j] = 1;
+ *       }
+ * }
+ *
+ * Set MCIF0_RFDC[RFFD] to the middle of the FDBK_Valid_Window.
+ *
+ * for (i = 0; i < Entire DQS Range; i++) {
+ *     MEMREAD(addr, actual_data);
+ *     if (actual_data == expected_data) {
+ *         DQS_Valid_Window[i] = 1;
+ *      }
+ * }
+ *
+ * Set MCIF0_RRQDC[RQFD] to the middle of the DQS_Valid_Window.
+ */
+/*-----------------------------------------------------------------------------+
+| DQS_calibration_methodB.
++-----------------------------------------------------------------------------*/
+static u32 DQS_calibration_methodB(struct ddrautocal *cal)
+{
+	ulong rfdc_reg;
+	ulong rffd;
+
+	ulong rqdc_reg;
+	ulong rqfd;
+
+	ulong rdcc;
+
+	u32 *membase;
+	ulong bxcf;
+	int rqfd_average;
+	int bxcr_num;
+	int rffd_average;
+	int pass;
+	uint passed = 0;
+
+	int in_window;
+	u32 curr_win_min, curr_win_max;
+	u32 best_win_min, best_win_max;
+	u32 size = 0;
+
+	/*------------------------------------------------------------------
+	 | Test to determine the best read clock delay tuning bits.
+	 |
+	 | Before the DDR controller can be used, the read clock delay needs to
+	 | be set.  This is SDRAM_RQDC[RQFD] and SDRAM_RFDC[RFFD].
+	 | This value cannot be hardcoded into the program because it changes
+	 | depending on the board's setup and environment.
+	 | To do this, all delay values are tested to see if they
+	 | work or not.  By doing this, you get groups of fails with groups of
+	 | passing values.  The idea is to find the start and end of a passing
+	 | window and take the center of it to use as the read clock delay.
+	 |
+	 | A failure has to be seen first so that when we hit a pass, we know
+	 | that it is truely the start of the window.  If we get passing values
+	 | to start off with, we don't know if we are at the start of the window
+	 |
+	 | The code assumes that a failure will always be found.
+	 | If a failure is not found, there is no easy way to get the middle
+	 | of the passing window.  I guess we can pretty much pick any value
+	 | but some values will be better than others.  Since the lowest speed
+	 | we can clock the DDR interface at is 200 MHz (2x 100 MHz PLB speed),
+	 | from experimentation it is safe to say you will always have a failure
+	 +-----------------------------------------------------------------*/
+
+	debug("\n\n");
+
+	in_window = 0;
+	rdcc = 0;
+
+	curr_win_min = curr_win_max = 0;
+	best_win_min = best_win_max = 0;
+	for (rffd = 0; rffd <= SDRAM_RFDC_RFFD_MAX; rffd++) {
+		mfsdram(SDRAM_RFDC, rfdc_reg);
+		rfdc_reg &= ~(SDRAM_RFDC_RFFD_MASK);
+		mtsdram(SDRAM_RFDC, rfdc_reg | SDRAM_RFDC_RFFD_ENCODE(rffd));
+
+		pass = 1;
+		for (bxcr_num = 0; bxcr_num < MAXBXCF; bxcr_num++) {
+			mfsdram(SDRAM_MB0CF + (bxcr_num<<2), bxcf);
+
+			/* Banks enabled */
+			if (bxcf & SDRAM_BXCF_M_BE_MASK) {
+				/* Bank is enabled */
+				membase = get_membase(bxcr_num);
+				pass &= short_mem_test(membase);
+			} /* if bank enabled */
+		} /* for bxcf_num */
+
+		/* If this value passed */
+		if (pass && !in_window) {	/* start of passing window */
+			in_window = 1;
+			curr_win_min = curr_win_max = rffd;
+			mfsdram(SDRAM_RDCC, rdcc);	/* record this value */
+		} else if (!pass && in_window) {	/* end passing window */
+			in_window = 0;
+		} else if (pass && in_window) {	/* within the passing window */
+			curr_win_max = rffd;
+		}
+
+		if (in_window) {
+			if ((curr_win_max - curr_win_min) >
+			    (best_win_max - best_win_min)) {
+				best_win_min = curr_win_min;
+				best_win_max = curr_win_max;
+				cal->rdcc    = rdcc;
+			}
+			passed = 1;
+		}
+	} /* for rffd */
+
+	if ((best_win_min == 0) && (best_win_max == 0))
+		passed = 0;
+	else
+		size = best_win_max - best_win_min;
+
+	debug("RFFD Min: 0x%x\n", best_win_min);
+	debug("RFFD Max: 0x%x\n", best_win_max);
+	rffd_average = ((best_win_min + best_win_max) / 2);
+
+	cal->rffd_min = best_win_min;
+	cal->rffd_max = best_win_max;
+
+	if (rffd_average < 0)
+		rffd_average = 0;
+
+	if (rffd_average > SDRAM_RFDC_RFFD_MAX)
+		rffd_average = SDRAM_RFDC_RFFD_MAX;
+
+	mtsdram(SDRAM_RFDC, rfdc_reg | SDRAM_RFDC_RFFD_ENCODE(rffd_average));
+
+	rffd = rffd_average;
+	in_window = 0;
+
+	curr_win_min = curr_win_max = 0;
+	best_win_min = best_win_max = 0;
+	for (rqfd = 0; rqfd <= SDRAM_RQDC_RQFD_MAX; rqfd++) {
+		mfsdram(SDRAM_RQDC, rqdc_reg);
+		rqdc_reg &= ~(SDRAM_RQDC_RQFD_MASK);
+		mtsdram(SDRAM_RQDC, rqdc_reg | SDRAM_RQDC_RQFD_ENCODE(rqfd));
+
+		pass = 1;
+		for (bxcr_num = 0; bxcr_num < MAXBXCF; bxcr_num++) {
+
+			mfsdram(SDRAM_MB0CF + (bxcr_num<<2), bxcf);
+
+			/* Banks enabled */
+			if (bxcf & SDRAM_BXCF_M_BE_MASK) {
+				/* Bank is enabled */
+				membase = get_membase(bxcr_num);
+				pass &= short_mem_test(membase);
+			} /* if bank enabled */
+		} /* for bxcf_num */
+
+		/* If this value passed */
+		if (pass && !in_window) {
+			in_window = 1;
+			curr_win_min = curr_win_max = rqfd;
+		} else if (!pass && in_window) {
+			in_window = 0;
+		} else if (pass && in_window) {
+			curr_win_max = rqfd;
+		}
+
+		if (in_window) {
+			if ((curr_win_max - curr_win_min) >
+			    (best_win_max - best_win_min)) {
+				best_win_min = curr_win_min;
+				best_win_max = curr_win_max;
+			}
+			passed = 1;
+		}
+	} /* for rqfd */
+
+	if ((best_win_min == 0) && (best_win_max == 0))
+		passed = 0;
+
+	debug("RQFD Min: 0x%x\n", best_win_min);
+	debug("RQFD Max: 0x%x\n", best_win_max);
+	rqfd_average = ((best_win_min + best_win_max) / 2);
+
+	if (rqfd_average < 0)
+		rqfd_average = 0;
+
+	if (rqfd_average > SDRAM_RQDC_RQFD_MAX)
+		rqfd_average = SDRAM_RQDC_RQFD_MAX;
+
+	mtsdram(SDRAM_RQDC, (rqdc_reg & ~SDRAM_RQDC_RQFD_MASK) |
+					SDRAM_RQDC_RQFD_ENCODE(rqfd_average));
+
+	mfsdram(SDRAM_RQDC, rqdc_reg);
+	mfsdram(SDRAM_RFDC, rfdc_reg);
+
+	/*
+	 * Need to program RQDC before RFDC. The value is read above.
+	 * That is the reason why auto cal not work.
+	 * See, comments below.
+	 */
+	mtsdram(SDRAM_RQDC, rqdc_reg);
+	mtsdram(SDRAM_RFDC, rfdc_reg);
+
+	debug("RQDC: 0x%08X\n", rqdc_reg);
+	debug("RFDC: 0x%08X\n", rfdc_reg);
+
+	/* if something passed, then return the size of the largest window */
+	if (passed != 0) {
+		passed		= size;
+		cal->rqfd	= rqfd_average;
+		cal->rffd	= rffd_average;
+	}
+
+	return (uint)passed;
+}
+#endif /* defined(CONFIG_PPC4xx_DDR_METHOD_A) */
+
+/*
+ * Default table for DDR auto-calibration of all
+ * possible WRDTR and CLKTR values.
+ * Table format is:
+ *	 {SDRAM_WRDTR.[WDTR], SDRAM_CLKTR.[CKTR]}
+ *
+ * Table is terminated with {-1, -1} value pair.
+ *
+ * Board vendors can specify their own board specific subset of
+ * known working {SDRAM_WRDTR.[WDTR], SDRAM_CLKTR.[CKTR]} value
+ * pairs via a board defined ddr_scan_option() function.
+ */
+struct sdram_timing full_scan_options[] = {
+	{0, 0}, {0, 1}, {0, 2}, {0, 3},
+	{1, 0}, {1, 1}, {1, 2}, {1, 3},
+	{2, 0}, {2, 1}, {2, 2}, {2, 3},
+	{3, 0}, {3, 1}, {3, 2}, {3, 3},
+	{4, 0}, {4, 1}, {4, 2}, {4, 3},
+	{5, 0}, {5, 1}, {5, 2}, {5, 3},
+	{6, 0}, {6, 1}, {6, 2}, {6, 3},
+	{-1, -1}
+};
+
+/*---------------------------------------------------------------------------+
+| DQS_calibration.
++----------------------------------------------------------------------------*/
+u32 DQS_autocalibration(void)
+{
+	u32 wdtr;
+	u32 clkp;
+	u32 result = 0;
+	u32 best_result = 0;
+	u32 best_rdcc;
+	struct ddrautocal ddrcal;
+	struct autocal_clks tcal;
+	ulong rfdc_reg;
+	ulong rqdc_reg;
+	u32 val;
+	int verbose_lvl = 0;
+	char *str;
+	char slash[] = "\\|/-\\|/-";
+	int loopi = 0;
+	struct sdram_timing *scan_list;
+
+#if defined(DEBUG_PPC4xx_DDR_AUTOCALIBRATION)
+	int i;
+	char tmp[64];	/* long enough for environment variables */
+#endif
+
+	memset(&tcal, 0, sizeof(tcal));
+
+	ddr_scan_option((ulong)full_scan_options);
+
+	scan_list =
+	      (struct sdram_timing *)ddr_scan_option((ulong)full_scan_options);
+
+	mfsdram(SDRAM_MCOPT1, val);
+	if ((val & SDRAM_MCOPT1_MCHK_CHK_REP) == SDRAM_MCOPT1_MCHK_CHK_REP)
+		str = "ECC Auto calibration -";
+	else
+		str = "Auto calibration -";
+
+	puts(str);
+
+#if defined(DEBUG_PPC4xx_DDR_AUTOCALIBRATION)
+	i = getenv_r("autocalib", tmp, sizeof(tmp));
+	if (i < 0)
+		strcpy(tmp, CONFIG_AUTOCALIB);
+
+	if (strcmp(tmp, "final") == 0) {
+		/* display the final autocalibration results only */
+		verbose_lvl = 1;
+	} else if (strcmp(tmp, "loop") == 0) {
+		/* display summary autocalibration info per iteration */
+		verbose_lvl = 2;
+	} else if (strcmp(tmp, "display") == 0) {
+		/* display full debug autocalibration window info. */
+		verbose_lvl = 3;
+	}
+#endif /* (DEBUG_PPC4xx_DDR_AUTOCALIBRATION) */
+
+	best_rdcc = (SDRAM_RDCC_RDSS_T4 >> 30);
+
+	while ((scan_list->wrdtr != -1) && (scan_list->clktr != -1)) {
+		wdtr = scan_list->wrdtr;
+		clkp = scan_list->clktr;
+
+		mfsdram(SDRAM_WRDTR, val);
+		val &= ~(SDRAM_WRDTR_LLWP_MASK | SDRAM_WRDTR_WTR_MASK);
+		mtsdram(SDRAM_WRDTR, (val |
+			ddr_wrdtr(SDRAM_WRDTR_LLWP_1_CYC | (wdtr << 25))));
+
+		mtsdram(SDRAM_CLKTR, clkp << 30);
+
+		putc('\b');
+		putc(slash[loopi++ % 8]);
+
+#ifdef DEBUG
+		debug("\n");
+		debug("*** --------------\n");
+		mfsdram(SDRAM_WRDTR, val);
+		debug("*** SDRAM_WRDTR set to 0x%08x\n", val);
+		mfsdram(SDRAM_CLKTR, val);
+		debug("*** SDRAM_CLKTR set to 0x%08x\n", val);
+#endif
+
+		debug("\n");
+		if (verbose_lvl > 2) {
+			printf("*** SDRAM_WRDTR (wdtr) set to %d\n", wdtr);
+			printf("*** SDRAM_CLKTR (clkp) set to %d\n", clkp);
+		}
+
+		memset(&ddrcal, 0, sizeof(ddrcal));
+
+		/*
+		 * DQS calibration.
+		 */
+		/*
+		 * program_DQS_calibration_method[A|B]() returns 0 if no
+		 * passing RFDC.[RFFD] window is found or returns the size
+		 * of the best passing window; in the case of a found passing
+		 * window, the ddrcal will contain the values of the best
+		 * window RQDC.[RQFD] and RFDC.[RFFD].
+		 */
+
+		/*
+		 * Call PPC4xx SDRAM DDR autocalibration methodA or methodB.
+		 * Default is methodB.
+		 * Defined the autocalibration method in the board specific
+		 * header file.
+		 * Please see include/configs/kilauea.h for an example for
+		 * a board specific implementation.
+		 */
+#if defined(CONFIG_PPC4xx_DDR_METHOD_A)
+		result = program_DQS_calibration_methodA(&ddrcal);
+#else
+		result = program_DQS_calibration_methodB(&ddrcal);
+#endif
+
+		sync();
+
+		/*
+		 * Clear potential errors resulting from auto-calibration.
+		 * If not done, then we could get an interrupt later on when
+		 * exceptions are enabled.
+		 */
+		set_mcsr(get_mcsr());
+
+		val = ddrcal.rdcc;	/* RDCC from the best passing window */
+
+		udelay(100);
+
+		if (verbose_lvl > 1) {
+			char *tstr;
+			switch ((val >> 30)) {
+			case 0:
+				if (result != 0)
+					tstr = "T1";
+				else
+					tstr = "N/A";
+				break;
+			case 1:
+				tstr = "T2";
+				break;
+			case 2:
+				tstr = "T3";
+				break;
+			case 3:
+				tstr = "T4";
+				break;
+			default:
+				tstr = "unknown";
+				break;
+			}
+			printf("** WRDTR(%d) CLKTR(%d), Wind (%d), best (%d), "
+			       "max-min(0x%04x)(0x%04x), RDCC: %s\n",
+				wdtr, clkp, result, best_result,
+				ddrcal.rffd_min, ddrcal.rffd_max, tstr);
+		}
+
+		/*
+		 * The DQS calibration "result" is either "0"
+		 * if no passing window was found, or is the
+		 * size of the RFFD passing window.
+		 */
+		if (result != 0) {
+			tcal.autocal.flags = 1;
+			debug("*** (%d)(%d) result passed window size: 0x%08x, "
+			      "rqfd = 0x%08x, rffd = 0x%08x, rdcc = 0x%08x\n",
+				wdtr, clkp, result, ddrcal.rqfd,
+				ddrcal.rffd, ddrcal.rdcc);
+			/*
+			 * Save the SDRAM_WRDTR and SDRAM_CLKTR
+			 * settings for the largest returned
+			 * RFFD passing window size.
+			 */
+			if (result > best_result) {
+				/*
+				 * want the lowest Read Sample Cycle Select
+				 */
+				val = (val & SDRAM_RDCC_RDSS_MASK) >> 30;
+				debug("*** (%d) (%d) current_rdcc, best_rdcc\n",
+							val, best_rdcc);
+				if (val <= best_rdcc) {
+					best_rdcc = val;
+					tcal.clocks.wrdtr = wdtr;
+					tcal.clocks.clktr = clkp;
+					tcal.clocks.rdcc = (val << 30);
+					tcal.autocal.rqfd = ddrcal.rqfd;
+					tcal.autocal.rffd = ddrcal.rffd;
+					best_result = result;
+
+					if (verbose_lvl > 2) {
+						printf("** (%d)(%d)  "
+						       "best result: 0x%04x\n",
+							wdtr, clkp,
+							best_result);
+						printf("** (%d)(%d)  "
+						       "best WRDTR: 0x%04x\n",
+							wdtr, clkp,
+							tcal.clocks.wrdtr);
+						printf("** (%d)(%d)  "
+						       "best CLKTR: 0x%04x\n",
+							wdtr, clkp,
+							tcal.clocks.clktr);
+						printf("** (%d)(%d)  "
+						       "best RQDC: 0x%04x\n",
+							wdtr, clkp,
+							tcal.autocal.rqfd);
+						printf("** (%d)(%d)  "
+						       "best RFDC: 0x%04x\n",
+							wdtr, clkp,
+							tcal.autocal.rffd);
+						printf("** (%d)(%d)  "
+						       "best RDCC: 0x%08x\n",
+							wdtr, clkp,
+							(u32)tcal.clocks.rdcc);
+						mfsdram(SDRAM_RTSR, val);
+						printf("** (%d)(%d)  best "
+						       "loop RTSR: 0x%08x\n",
+							wdtr, clkp, val);
+						mfsdram(SDRAM_FCSR, val);
+						printf("** (%d)(%d)  best "
+						       "loop FCSR: 0x%08x\n",
+							wdtr, clkp, val);
+					}
+				} /* if (val <= best_rdcc) */
+			} /* if (result >= best_result) */
+		} /* if (result != 0) */
+		scan_list++;
+	} /* while ((scan_list->wrdtr != -1) && (scan_list->clktr != -1)) */
+
+	if (tcal.autocal.flags == 1) {
+		if (verbose_lvl > 0) {
+			printf("*** --------------\n");
+			printf("*** best_result window size: %d\n",
+							best_result);
+			printf("*** best_result WRDTR: 0x%04x\n",
+							tcal.clocks.wrdtr);
+			printf("*** best_result CLKTR: 0x%04x\n",
+							tcal.clocks.clktr);
+			printf("*** best_result RQFD: 0x%04x\n",
+							tcal.autocal.rqfd);
+			printf("*** best_result RFFD: 0x%04x\n",
+							tcal.autocal.rffd);
+			printf("*** best_result RDCC: 0x%04x\n",
+							tcal.clocks.rdcc);
+			printf("*** --------------\n");
+			printf("\n");
+		}
+
+		/*
+		 * if got best passing result window, then lock in the
+		 * best CLKTR, WRDTR, RQFD, and RFFD values
+		 */
+		mfsdram(SDRAM_WRDTR, val);
+		mtsdram(SDRAM_WRDTR, (val &
+		    ~(SDRAM_WRDTR_LLWP_MASK | SDRAM_WRDTR_WTR_MASK)) |
+		    ddr_wrdtr(SDRAM_WRDTR_LLWP_1_CYC |
+					(tcal.clocks.wrdtr << 25)));
+
+		mtsdram(SDRAM_CLKTR, tcal.clocks.clktr << 30);
+
+		mfsdram(SDRAM_RQDC, rqdc_reg);
+		rqdc_reg &= ~(SDRAM_RQDC_RQFD_MASK);
+		mtsdram(SDRAM_RQDC, rqdc_reg |
+				SDRAM_RQDC_RQFD_ENCODE(tcal.autocal.rqfd));
+
+		mfsdram(SDRAM_RQDC, rqdc_reg);
+		debug("*** best_result: read value SDRAM_RQDC 0x%08x\n",
+				rqdc_reg);
+
+		mfsdram(SDRAM_RFDC, rfdc_reg);
+		rfdc_reg &= ~(SDRAM_RFDC_RFFD_MASK);
+		mtsdram(SDRAM_RFDC, rfdc_reg |
+				SDRAM_RFDC_RFFD_ENCODE(tcal.autocal.rffd));
+
+		mfsdram(SDRAM_RFDC, rfdc_reg);
+		debug("*** best_result: read value SDRAM_RFDC 0x%08x\n",
+				rfdc_reg);
+		mfsdram(SDRAM_RDCC, val);
+		debug("***  SDRAM_RDCC 0x%08x\n", val);
+	} else {
+		/*
+		 * no valid windows were found
+		 */
+		printf("DQS memory calibration window can not be determined, "
+		       "terminating u-boot.\n");
+		ppc4xx_ibm_ddr2_register_dump();
+		spd_ddr_init_hang();
+	}
+
+	blank_string(strlen(str));
+
+	return 0;
+}
+#else /* defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_NAND_SPL) */
+u32 DQS_autocalibration(void)
+{
+	return 0;
+}
+#endif /* !defined(CONFIG_NAND_U_BOOT) && !defined(CONFIG_NAND_SPL) */
+#endif /* defined(CONFIG_PPC4xx_DDR_AUTOCALIBRATION) */
-- 
1.5.5



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