[U-Boot] ppc4xx: Optimizations/Cleanups for IBM DDR2 Memory Controller
Prodyut Hazarika
phazarika at amcc.com
Thu Aug 28 01:39:00 CEST 2008
>From bdc99201a532b040b3d346fca5acff8332d670e4 Mon Sep 17 00:00:00 2001
From: Prodyut Hazarika <phazarika at amcc.com>
Date: Wed, 27 Aug 2008 16:26:36 -0700
Subject: [PATCH] Optimizations/Cleanups for IBM DDR2 memory controller
Removed Magic numbers from Initialization preload registers
Tested with Kilauea, Glacier, Canyonlands and Katmai boards
About 5-7% improvement seen for LMBench memtests
Signed-off-by: Prodyut Hazarika <phazarika at amcc.com>
---
cpu/ppc4xx/44x_spd_ddr2.c | 73 ++++++++++++++++++++++++++++++++++----------
1 files changed, 56 insertions(+), 17 deletions(-)
diff --git a/cpu/ppc4xx/44x_spd_ddr2.c b/cpu/ppc4xx/44x_spd_ddr2.c
index 001f2c1..15250d4 100644
--- a/cpu/ppc4xx/44x_spd_ddr2.c
+++ b/cpu/ppc4xx/44x_spd_ddr2.c
@@ -118,6 +118,7 @@ static inline void ppc4xx_ibm_ddr2_register_dump(void);
#define ODS_FULL 0x00000000
#define ODS_REDUCED 0x00000002
+#define OCD_CALIB_DEF 0x00000380
/* defines for ODT (On Die Termination) of the 440SP(e) DDR2 controller */
#define ODT_EB0R (0x80000000 >> 8)
@@ -570,15 +571,24 @@ phys_size_t initdram(int board_type)
mtsdram(SDRAM_MCOPT2,
(val & ~(SDRAM_MCOPT2_SREN_MASK | SDRAM_MCOPT2_DCEN_MASK |
SDRAM_MCOPT2_IPTR_MASK | SDRAM_MCOPT2_ISIE_MASK)) |
- (SDRAM_MCOPT2_DCEN_ENABLE | SDRAM_MCOPT2_IPTR_EXECUTE));
+ SDRAM_MCOPT2_IPTR_EXECUTE);
/*------------------------------------------------------------------
- * Wait for SDRAM_CFG0_DC_EN to complete.
+ * Wait for IPTR_EXECUTE init sequence to complete.
*-----------------------------------------------------------------*/
do {
mfsdram(SDRAM_MCSTAT, val);
} while ((val & SDRAM_MCSTAT_MIC_MASK) == SDRAM_MCSTAT_MIC_NOTCOMP);
+ /* enable the controller only after init sequence completes */
+ mfsdram(SDRAM_MCOPT2, val);
+ mtsdram(SDRAM_MCOPT2, (val | SDRAM_MCOPT2_DCEN_ENABLE));
+
+ /* Make sure delay-line calibration is done before proceeding */
+ do {
+ mfsdram(SDRAM_DLCR, val);
+ } while (!(val & SDRAM_DLCR_DLCS_COMPLETE));
+
/* get installed memory size */
dram_size = sdram_memsize();
@@ -1343,22 +1353,50 @@ static void program_initplr(unsigned long *dimm_populated,
emr = CMD_EMR | SELECT_EMR | odt | ods;
emr2 = CMD_EMR | SELECT_EMR2;
emr3 = CMD_EMR | SELECT_EMR3;
- mtsdram(SDRAM_INITPLR0, 0xB5000000 | CMD_NOP); /* NOP */
+ /* NOP - Wait 106 MemClk cycles */
+ mtsdram(SDRAM_INITPLR0, SDRAM_INITPLR_ENABLE | CMD_NOP |
+ SDRAM_INITPLR_IMWT_ENCODE(106));
udelay(1000);
- mtsdram(SDRAM_INITPLR1, 0x82000400 | CMD_PRECHARGE); /* precharge 8 DDR clock cycle */
- mtsdram(SDRAM_INITPLR2, 0x80800000 | emr2); /* EMR2 */
- mtsdram(SDRAM_INITPLR3, 0x80800000 | emr3); /* EMR3 */
- mtsdram(SDRAM_INITPLR4, 0x80800000 | emr); /* EMR DLL ENABLE */
- mtsdram(SDRAM_INITPLR5, 0x80800000 | mr | DLL_RESET); /* MR w/ DLL reset */
+ /* precharge 4 MemClk cycles */
+ mtsdram(SDRAM_INITPLR1, SDRAM_INITPLR_ENABLE | CMD_PRECHARGE |
+ SDRAM_INITPLR_IMWT_ENCODE(4));
+ /* EMR2 - Wait tMRD (2 MemClk cycles) */
+ mtsdram(SDRAM_INITPLR2, SDRAM_INITPLR_ENABLE | emr2 |
+ SDRAM_INITPLR_IMWT_ENCODE(2));
+ /* EMR3 - Wait tMRD (2 MemClk cycles) */
+ mtsdram(SDRAM_INITPLR3, SDRAM_INITPLR_ENABLE | emr3 |
+ SDRAM_INITPLR_IMWT_ENCODE(2));
+ /* EMR DLL ENABLE - Wait tMRD (2 MemClk cycles) */
+ mtsdram(SDRAM_INITPLR4, SDRAM_INITPLR_ENABLE | emr |
+ SDRAM_INITPLR_IMWT_ENCODE(2));
+ /* MR w/ DLL reset - 200 cycle wait for DLL reset */
+ mtsdram(SDRAM_INITPLR5, SDRAM_INITPLR_ENABLE | mr | DLL_RESET |
+ SDRAM_INITPLR_IMWT_ENCODE(200));
udelay(1000);
- mtsdram(SDRAM_INITPLR6, 0x82000400 | CMD_PRECHARGE); /* precharge 8 DDR clock cycle */
- mtsdram(SDRAM_INITPLR7, 0x8a000000 | CMD_REFRESH); /* Refresh 50 DDR clock cycle */
- mtsdram(SDRAM_INITPLR8, 0x8a000000 | CMD_REFRESH); /* Refresh 50 DDR clock cycle */
- mtsdram(SDRAM_INITPLR9, 0x8a000000 | CMD_REFRESH); /* Refresh 50 DDR clock cycle */
- mtsdram(SDRAM_INITPLR10, 0x8a000000 | CMD_REFRESH); /* Refresh 50 DDR clock cycle */
- mtsdram(SDRAM_INITPLR11, 0x80000000 | mr); /* MR w/o DLL reset */
- mtsdram(SDRAM_INITPLR12, 0x80800380 | emr); /* EMR OCD Default */
- mtsdram(SDRAM_INITPLR13, 0x80800000 | emr); /* EMR OCD Exit */
+ /* precharge 4 MemClk cycles */
+ mtsdram(SDRAM_INITPLR6, SDRAM_INITPLR_ENABLE | CMD_PRECHARGE |
+ SDRAM_INITPLR_IMWT_ENCODE(4));
+ /* Refresh 25 MemClk cycles */
+ mtsdram(SDRAM_INITPLR7, SDRAM_INITPLR_ENABLE | CMD_REFRESH |
+ SDRAM_INITPLR_IMWT_ENCODE(25));
+ /* Refresh 25 MemClk cycles */
+ mtsdram(SDRAM_INITPLR8, SDRAM_INITPLR_ENABLE | CMD_REFRESH |
+ SDRAM_INITPLR_IMWT_ENCODE(25));
+ /* Refresh 25 MemClk cycles */
+ mtsdram(SDRAM_INITPLR9, SDRAM_INITPLR_ENABLE | CMD_REFRESH |
+ SDRAM_INITPLR_IMWT_ENCODE(25));
+ /* Refresh 25 MemClk cycles */
+ mtsdram(SDRAM_INITPLR10, SDRAM_INITPLR_ENABLE | CMD_REFRESH |
+ SDRAM_INITPLR_IMWT_ENCODE(25));
+ /* MR w/o DLL reset - Wait tMRD (2 MemClk cycles) */
+ mtsdram(SDRAM_INITPLR11, SDRAM_INITPLR_ENABLE | mr |
+ SDRAM_INITPLR_IMWT_ENCODE(2));
+ /* EMR OCD Default - Wait tMRD (2 MemClk cycles) */
+ mtsdram(SDRAM_INITPLR12, SDRAM_INITPLR_ENABLE | OCD_CALIB_DEF |
+ SDRAM_INITPLR_IMWT_ENCODE(2) | emr);
+ /* EMR OCD Exit */
+ mtsdram(SDRAM_INITPLR13, SDRAM_INITPLR_ENABLE | emr |
+ SDRAM_INITPLR_IMWT_ENCODE(2));
} else {
printf("ERROR: ucode error as unknown DDR type in program_initplr");
spd_ddr_init_hang ();
@@ -2466,12 +2504,13 @@ static void program_DQS_calibration(unsigned long *dimm_populated,
* Program RFDC register
* Set Feedback Fractional Oversample
* Auto-detect read sample cycle enable
+ * Set RFOS to 1/4 of memclk cycle (0x3f)
*-----------------------------------------------------------------*/
mfsdram(SDRAM_RFDC, val);
mtsdram(SDRAM_RFDC,
(val & ~(SDRAM_RFDC_ARSE_MASK | SDRAM_RFDC_RFOS_MASK |
SDRAM_RFDC_RFFD_MASK))
- | (SDRAM_RFDC_ARSE_ENABLE | SDRAM_RFDC_RFOS_ENCODE(0) |
+ | (SDRAM_RFDC_ARSE_ENABLE | SDRAM_RFDC_RFOS_ENCODE(0x3f) |
SDRAM_RFDC_RFFD_ENCODE(0)));
DQS_calibration_process();
--
1.5.5
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