diff options
| author | York Sun <yorksun@freescale.com> | 2011-05-27 07:25:48 +0800 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2011-07-11 13:24:19 -0500 |
| commit | e090aa7cf05fe3cde7ce751cbb4f0c59cc113035 (patch) | |
| tree | 3cf46cbd21f8afb0895221ad827abc8c1de3f7a9 /arch/powerpc/cpu/mpc8xxx | |
| parent | 26fd33b9be0ccfbefcfe89fe1632bbff0fc901c6 (diff) | |
powerpc/mpc8xxx: adjust DDR burst length and chop accroding to sdram width
If the bus width is 32-bit, burst chop should be disabled and burst length
should be 8. Read from SPD or other source to determine the width.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/cpu/mpc8xxx')
| -rw-r--r-- | arch/powerpc/cpu/mpc8xxx/ddr/options.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/options.c b/arch/powerpc/cpu/mpc8xxx/ddr/options.c index 6ccc3b0c70..80c7046478 100644 --- a/arch/powerpc/cpu/mpc8xxx/ddr/options.c +++ b/arch/powerpc/cpu/mpc8xxx/ddr/options.c @@ -418,8 +418,19 @@ unsigned int populate_memctl_options(int all_DIMMs_registered, /* Choose dynamic power management mode. */ popts->dynamic_power = 0; - /* 0 = 64-bit, 1 = 32-bit, 2 = 16-bit */ - popts->data_bus_width = 0; + /* + * check first dimm for primary sdram width + * presuming all dimms are similar + * 0 = 64-bit, 1 = 32-bit, 2 = 16-bit + */ + if (pdimm[0].primary_sdram_width == 64) + popts->data_bus_width = 0; + else if (pdimm[0].primary_sdram_width == 32) + popts->data_bus_width = 1; + else if (pdimm[0].primary_sdram_width == 16) + popts->data_bus_width = 2; + else + panic("Error: invalid primary sdram width!\n"); /* Choose burst length. */ #if defined(CONFIG_FSL_DDR3) @@ -427,8 +438,13 @@ unsigned int populate_memctl_options(int all_DIMMs_registered, popts->OTF_burst_chop_en = 0; /* on-the-fly burst chop disable */ popts->burst_length = DDR_BL8; /* Fixed 8-beat burst len */ #else - popts->OTF_burst_chop_en = 1; /* on-the-fly burst chop */ - popts->burst_length = DDR_OTF; /* on-the-fly BC4 and BL8 */ + if (popts->data_bus_width == 1) { /* 32-bit bus */ + popts->OTF_burst_chop_en = 0; + popts->burst_length = DDR_BL8; + } else { + popts->OTF_burst_chop_en = 1; /* on-the-fly burst chop */ + popts->burst_length = DDR_OTF; /* on-the-fly BC4 and BL8 */ + } #endif #else popts->burst_length = DDR_BL4; /* has to be 4 for DDR2 */ |