From 845c6c95dbfe6c915ce68a0a115852fa17932fb4 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Sat, 5 Jan 2008 09:12:41 +0100 Subject: ppc4xx: Update Katmai/44x_spd_ddr2.c code for optimal DDR2 setup On Katmai the complete auto-calibration somehow doesn't seem to produce the best results, meaning optimal values for RQFD/RFFD. This was discovered by GDA using a high bandwidth scope, analyzing the DDR2 signals. GDA provided a fixed value for RQFD, so now on Katmai "only" RFFD is auto-calibrated. This patch also adds RDCC calibration as mentioned on page 7 of the AMCC PowerPC440SP/SPe DDR2 application note: "DDR1/DDR2 Initialization Sequence and Dynamic Tuning" Signed-off-by: Stefan Roese --- cpu/ppc4xx/44x_spd_ddr2.c | 52 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 37 insertions(+), 15 deletions(-) (limited to 'cpu') diff --git a/cpu/ppc4xx/44x_spd_ddr2.c b/cpu/ppc4xx/44x_spd_ddr2.c index e199294..2475ed9 100644 --- a/cpu/ppc4xx/44x_spd_ddr2.c +++ b/cpu/ppc4xx/44x_spd_ddr2.c @@ -3,7 +3,7 @@ * This SPD SDRAM detection code supports AMCC PPC44x cpu's with a * DDR2 controller (non Denali Core). Those are 440SP/SPe. * - * (C) Copyright 2007 + * (C) Copyright 2007-2008 * Stefan Roese, DENX Software Engineering, sr@denx.de. * * COPYRIGHT AMCC CORPORATION 2004 @@ -2409,17 +2409,10 @@ static void program_DQS_calibration(unsigned long *dimm_populated, * Read sample cycle auto-update enable *-----------------------------------------------------------------*/ - /* - * Modified for the Katmai platform: with some DIMMs, the DDR2 - * controller automatically selects the T2 read cycle, but this - * proves unreliable. Go ahead and force the DDR2 controller - * to use the T4 sample and disable the automatic update of the - * RDSS field. - */ mfsdram(SDRAM_RDCC, val); mtsdram(SDRAM_RDCC, (val & ~(SDRAM_RDCC_RDSS_MASK | SDRAM_RDCC_RSAE_MASK)) - | (SDRAM_RDCC_RDSS_T4 | SDRAM_RDCC_RSAE_DISABLE)); + | SDRAM_RDCC_RSAE_ENABLE); /*------------------------------------------------------------------ * Program RQDC register @@ -2512,10 +2505,7 @@ static void DQS_calibration_process(void) { unsigned long rfdc_reg; unsigned long rffd; - unsigned long rqdc_reg; - unsigned long rqfd; unsigned long val; - long rqfd_average; long rffd_average; long max_start; long min_end; @@ -2533,10 +2523,14 @@ static void DQS_calibration_process(void) long max_end; unsigned char fail_found; unsigned char pass_found; +#if !defined(CONFIG_DDR_RQDC_FIXED) + u32 rqdc_reg; + u32 rqfd; u32 rqfd_start; + u32 rqfd_average; + int loopi = 0; char str[] = "Auto calibration -"; char slash[] = "\\|/-\\|/-"; - int loopi = 0; /*------------------------------------------------------------------ * Test to determine the best read clock delay tuning bits. @@ -2571,6 +2565,16 @@ calibration_loop: mfsdram(SDRAM_RQDC, rqdc_reg); mtsdram(SDRAM_RQDC, (rqdc_reg & ~SDRAM_RQDC_RQFD_MASK) | SDRAM_RQDC_RQFD_ENCODE(rqfd_start)); +#else /* CONFIG_DDR_RQDC_FIXED */ + /* + * On Katmai the complete auto-calibration somehow doesn't seem to + * produce the best results, meaning optimal values for RQFD/RFFD. + * This was discovered by GDA using a high bandwidth scope, + * analyzing the DDR2 signals. GDA provided a fixed value for RQFD, + * so now on Katmai "only" RFFD is auto-calibrated. + */ + mtsdram(SDRAM_RQDC, CONFIG_DDR_RQDC_FIXED); +#endif /* CONFIG_DDR_RQDC_FIXED */ max_start = 0; min_end = 0; @@ -2655,6 +2659,7 @@ calibration_loop: /* now fix RFDC[RFFD] found and find RQDC[RQFD] */ mtsdram(SDRAM_RFDC, rfdc_reg | SDRAM_RFDC_RFFD_ENCODE(rffd_average)); +#if !defined(CONFIG_DDR_RQDC_FIXED) max_pass_length = 0; max_start = 0; max_end = 0; @@ -2727,8 +2732,6 @@ calibration_loop: spd_ddr_init_hang (); } - blank_string(strlen(str)); - if (rqfd_average < 0) rqfd_average = 0; @@ -2739,12 +2742,31 @@ calibration_loop: (rqdc_reg & ~SDRAM_RQDC_RQFD_MASK) | SDRAM_RQDC_RQFD_ENCODE(rqfd_average)); + blank_string(strlen(str)); +#endif /* CONFIG_DDR_RQDC_FIXED */ + + /* + * Now complete RDSS configuration as mentioned on page 7 of the AMCC + * PowerPC440SP/SPe DDR2 application note: + * "DDR1/DDR2 Initialization Sequence and Dynamic Tuning" + */ + mfsdram(SDRAM_RTSR, val); + if ((val & SDRAM_RTSR_TRK1SM_MASK) == SDRAM_RTSR_TRK1SM_ATPLS1) { + mfsdram(SDRAM_RDCC, val); + if ((val & SDRAM_RDCC_RDSS_MASK) != SDRAM_RDCC_RDSS_T4) { + val += 0x40000000; + mtsdram(SDRAM_RDCC, val); + } + } + mfsdram(SDRAM_DLCR, val); debug("%s[%d] DLCR: 0x%08X\n", __FUNCTION__, __LINE__, val); mfsdram(SDRAM_RQDC, val); debug("%s[%d] RQDC: 0x%08X\n", __FUNCTION__, __LINE__, val); mfsdram(SDRAM_RFDC, val); debug("%s[%d] RFDC: 0x%08X\n", __FUNCTION__, __LINE__, val); + mfsdram(SDRAM_RDCC, val); + debug("%s[%d] RDCC: 0x%08X\n", __FUNCTION__, __LINE__, val); } #else /* calibration test with hardvalues */ /*-----------------------------------------------------------------------------+ -- cgit v1.1