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authorYork Sun <yorksun@freescale.com>2010-10-18 13:46:50 -0700
committerKumar Gala <galak@kernel.crashing.org>2010-10-20 02:38:40 -0500
commit58edbc9caaef4efbf12de8a451d70c2ad86934bf (patch)
treed3ac54a57f26d2bd7fdb3c66243b757b9b9f99dc
parent28a966715be78fc35147086e68fc80aeb21235b1 (diff)
Disable unused chip-select for DDR controller interleaving
When DDR controller interleaving is eabled and less than all bank (chip-select) interleaving is seletected, the unused chip-select should be disabled. Signed-off-by: York Sun <yorksun@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
-rw-r--r--arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c b/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c
index e82082e74c..3fec100377 100644
--- a/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c
+++ b/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c
@@ -1184,6 +1184,7 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
unsigned int sr_it;
unsigned int zq_en;
unsigned int wrlvl_en;
+ int cs_en = 1;
memset(ddr, 0, sizeof(fsl_ddr_cfg_regs_t));
@@ -1250,16 +1251,23 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
* and each controller uses rank interleaving within
* itself. Therefore the starting and ending address
* on each controller is twice the amount present on
- * each controller.
+ * each controller. If any CS is not included in the
+ * interleaving, the memory on that CS is not accssible
+ * and the total memory size is reduced. The CS is also
+ * disabled.
*/
unsigned long long ctlr_density = 0;
switch (popts->ba_intlv_ctl & FSL_DDR_CS0_CS1_CS2_CS3) {
case FSL_DDR_CS0_CS1:
case FSL_DDR_CS0_CS1_AND_CS2_CS3:
ctlr_density = dimm_params[0].rank_density * 2;
+ if (i > 1)
+ cs_en = 0;
break;
case FSL_DDR_CS2_CS3:
ctlr_density = dimm_params[0].rank_density;
+ if (i > 0)
+ cs_en = 0;
break;
case FSL_DDR_CS0_CS1_CS2_CS3:
/*
@@ -1379,8 +1387,11 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
);
debug("FSLDDR: cs[%d]_bnds = 0x%08x\n", i, ddr->cs[i].bnds);
- set_csn_config(dimm_number, i, ddr, popts, dimm_params);
- set_csn_config_2(i, ddr);
+ if (cs_en) {
+ set_csn_config(dimm_number, i, ddr, popts, dimm_params);
+ set_csn_config_2(i, ddr);
+ } else
+ printf("CS%d is disabled.\n", i);
}
set_ddr_eor(ddr, popts);