From 91a414c7d1fb0eac912592cd995b30c9f23045c9 Mon Sep 17 00:00:00 2001 From: John Traill Date: Tue, 8 Aug 2006 11:32:43 +0100 Subject: Fix caslat calculation Signed-off-by: John Traill --- cpu/mpc86xx/spd_sdram.c | 135 ++++++++++++++---------------------------------- 1 file changed, 39 insertions(+), 96 deletions(-) (limited to 'cpu/mpc86xx') diff --git a/cpu/mpc86xx/spd_sdram.c b/cpu/mpc86xx/spd_sdram.c index f30bbbd7e2..a4b9d54c7b 100644 --- a/cpu/mpc86xx/spd_sdram.c +++ b/cpu/mpc86xx/spd_sdram.c @@ -44,7 +44,7 @@ extern int dma_xfer(void *dest, uint count, void *src); /* * Only one of the following three should be 1; others should be 0 * By default the cache line interleaving is selected if - * the CONFIG_DDR_INTERLEAVE flag is defined in MPC8641HPCN.h + * the CONFIG_DDR_INTERLEAVE flag is defined */ #define CFG_PAGE_INTERLEAVING 0 #define CFG_BANK_INTERLEAVING 0 @@ -137,8 +137,8 @@ convert_bcd_tenths_to_cycle_time_ps(unsigned int spd_val) 800, 900, 250, - 330, /* FIXME: Is 333 better/valid? */ - 660, /* FIXME: Is 667 better/valid? */ + 330, + 660, 750, 0, /* undefined */ 0 /* undefined */ @@ -167,7 +167,7 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, unsigned int dqs_cfg; unsigned char twr_clk, twtr_clk, twr_auto_clk; unsigned int tCKmin_ps, tCKmax_ps; - unsigned int max_data_rate, effective_data_rate; + unsigned int max_data_rate; unsigned int busfreq; unsigned sdram_cfg_1; unsigned int memsize; @@ -187,6 +187,7 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, unsigned char d_init; unsigned int law_size; volatile ccsr_local_mcm_t *mcm = &immap->im_local_mcm; + unsigned int tCycle_ps, modfreq; if (ddr_num == 1) ddr = &immap->im_ddr1; @@ -288,7 +289,7 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, } #ifdef CONFIG_DDR_INTERLEAVE -#ifdef CONFIG_MPC8641HPCN + if (dimm_num != 1) { printf("For interleaving memory on HPCN, need to use DIMM 1 for DDR Controller %d !\n", ddr_num); return 0; @@ -340,8 +341,6 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, rank_density /= 2; } } -#endif /* CONFIG_MPC8641HPCN */ - #else /* CONFIG_DDR_INTERLEAVE */ if (dimm_num == 1) { @@ -468,81 +467,42 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, */ busfreq = get_bus_freq(0) / 1000000; /* MHz */ - effective_data_rate = max_data_rate; - if (busfreq < 90) { - /* DDR rate out-of-range */ - puts("DDR: platform frequency is not fit for DDR rate\n"); + if ((spd.mem_type == SPD_MEMTYPE_DDR2) && (busfreq < 266)) { + printf("DDR: platform frequency too low for correct DDR2 controller operation\n"); return 0; - - } else if (90 <= busfreq && busfreq < 230 && max_data_rate >= 230) { - /* - * busfreq 90~230 range, treated as DDR 200. - */ - effective_data_rate = 200; - if (spd.clk_cycle3 == 0xa0) /* 10 ns */ - caslat -= 2; - else if (spd.clk_cycle2 == 0xa0) - caslat--; - - } else if (230 <= busfreq && busfreq < 280 && max_data_rate >= 280) { - /* - * busfreq 230~280 range, treated as DDR 266. - */ - effective_data_rate = 266; - if (spd.clk_cycle3 == 0x75) /* 7.5 ns */ - caslat -= 2; - else if (spd.clk_cycle2 == 0x75) - caslat--; - - } else if (280 <= busfreq && busfreq < 350 && max_data_rate >= 350) { - /* - * busfreq 280~350 range, treated as DDR 333. - */ - effective_data_rate = 333; - if (spd.clk_cycle3 == 0x60) /* 6.0 ns */ - caslat -= 2; - else if (spd.clk_cycle2 == 0x60) - caslat--; - - } else if (350 <= busfreq && busfreq < 460 && max_data_rate >= 460) { - /* - * busfreq 350~460 range, treated as DDR 400. - */ - effective_data_rate = 400; - if (spd.clk_cycle3 == 0x50) /* 5.0 ns */ - caslat -= 2; - else if (spd.clk_cycle2 == 0x50) - caslat--; - - } else if (460 <= busfreq && busfreq < 560 && max_data_rate >= 560) { - /* - * busfreq 460~560 range, treated as DDR 533. - */ - effective_data_rate = 533; - if (spd.clk_cycle3 == 0x3D) /* 3.75 ns */ - caslat -= 2; - else if (spd.clk_cycle2 == 0x3D) - caslat--; - - } else if (560 <= busfreq && busfreq < 700 && max_data_rate >= 700) { - /* - * busfreq 560~700 range, treated as DDR 667. - */ - effective_data_rate = 667; - if (spd.clk_cycle3 == 0x30) /* 3.0 ns */ - caslat -= 2; - else if (spd.clk_cycle2 == 0x30) - caslat--; - - } else if (700 <= busfreq) { - /* - * DDR rate out-of-range - */ - printf("DDR: Bus freq %d MHz is not fit for DDR rate %d MHz\n", - busfreq, max_data_rate); + } else if (busfreq < 90) { + printf("DDR: platform frequency too low for correct DDR1 operation\n"); return 0; } + if ((busfreq <= modfreq) && (spd.cas_lat & (1 << (caslat - 2)))) { + caslat -= 2; + } else { + tCycle_ps = convert_bcd_tenths_to_cycle_time_ps(spd.clk_cycle2); + modfreq = 2 * 1000 * 1000 / tCycle_ps; + if ((busfreq <= modfreq) && (spd.cas_lat & (1 << (caslat - 1)))) + caslat -= 1; + else if (busfreq > max_data_rate) { + printf("DDR: Bus freq %d MHz is not fit for DDR rate %d MHz\n", + busfreq, max_data_rate); + return 0; + } + } + + /* + * Empirically set ~MCAS-to-preamble override for DDR 2. + * Your milage will vary. + */ + cpo = 0; + if (spd.mem_type == SPD_MEMTYPE_DDR2) { + if (busfreq <= 333) { + cpo = 0x7; + } else if (busfreq <= 400) { + cpo = 0x9; + } else { + cpo = 0xa; + } + } /* * Convert caslat clocks to DDR controller value. @@ -554,7 +514,6 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, caslat_ctrl = (2 * caslat - 1) & 0x0f; } - debug("DDR: effective data rate is %d MHz\n", effective_data_rate); debug("DDR: caslat SPD bit is %d, controller field is 0x%x\n", caslat, caslat_ctrl); @@ -676,7 +635,7 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, && (odt_wr_cfg || odt_rd_cfg) && (caslat < 4)) { add_lat = 4 - caslat; - if (add_lat > trcd_clk) { + if (add_lat >= trcd_clk) { add_lat = trcd_clk - 1; } } @@ -717,22 +676,6 @@ spd_init(unsigned char i2c_address, unsigned int ddr_num, four_act = picos_to_clk(37500); /* By the book. 1k pages? */ } - /* - * Empirically set ~MCAS-to-preamble override for DDR 2. - * Your milage will vary. - */ - cpo = 0; - if (spd.mem_type == SPD_MEMTYPE_DDR2) { - if (effective_data_rate == 266 || effective_data_rate == 333) { - cpo = 0x7; /* READ_LAT + 5/4 */ - } else if (effective_data_rate == 400) { - cpo = 0x9; /* READ_LAT + 7/4 */ - } else { - /* Pure speculation */ - cpo = 0xb; - } - } - ddr->timing_cfg_2 = (0 | ((add_lat & 0x7) << 28) /* ADD_LAT */ | ((cpo & 0x1f) << 23) /* CPO */ -- cgit v1.2.1