From bdc99201a532b040b3d346fca5acff8332d670e4 Mon Sep 17 00:00:00 2001

From: Prodyut Hazarika phazarika@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@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();