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| author | Tom Rini <trini@ti.com> | 2013-02-26 16:35:33 -0500 |
|---|---|---|
| committer | Tom Rini <trini@ti.com> | 2013-03-08 16:41:12 -0500 |
| commit | 1c382ead7a0081140e4961f2a03a20abd5e41f05 (patch) | |
| tree | d89e94e33fcdaf6780b7b675e38526eb263a5353 /arch/arm/cpu | |
| parent | 98bc1228c800005e7addf95632e23079a236e5f5 (diff) | |
| download | u-boot-imx-1c382ead7a0081140e4961f2a03a20abd5e41f05.zip u-boot-imx-1c382ead7a0081140e4961f2a03a20abd5e41f05.tar.gz u-boot-imx-1c382ead7a0081140e4961f2a03a20abd5e41f05.tar.bz2 | |
am33xx: Update DDR3 EMIF configuration sequence
Based on
http://processors.wiki.ti.com/index.php/AM335x_EMIF_Configuration_tips
we need to re-work our sequence in config_sdram slightly to match what
the TRM describes as the correct sequence. In our current (incorrect)
sequence some edge cases may fail to initalize correctly.
Signed-off-by: Tom Rini <trini@ti.com>
Diffstat (limited to 'arch/arm/cpu')
| -rw-r--r-- | arch/arm/cpu/armv7/am33xx/ddr.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/arm/cpu/armv7/am33xx/ddr.c b/arch/arm/cpu/armv7/am33xx/ddr.c index fd9fc4a..448cc40 100644 --- a/arch/arm/cpu/armv7/am33xx/ddr.c +++ b/arch/arm/cpu/armv7/am33xx/ddr.c @@ -45,13 +45,19 @@ static struct ddr_cmdtctrl *ioctrl_reg = { */ void config_sdram(const struct emif_regs *regs) { - writel(regs->ref_ctrl, &emif_reg->emif_sdram_ref_ctrl); - writel(regs->ref_ctrl, &emif_reg->emif_sdram_ref_ctrl_shdw); - if (regs->zq_config){ + if (regs->zq_config) { + /* + * A value of 0x2800 for the REF CTRL will give us + * about 570us for a delay, which will be long enough + * to configure things. + */ + writel(0x2800, &emif_reg->emif_sdram_ref_ctrl); writel(regs->zq_config, &emif_reg->emif_zq_config); writel(regs->sdram_config, &cstat->secure_emif_sdram_config); } writel(regs->sdram_config, &emif_reg->emif_sdram_config); + writel(regs->ref_ctrl, &emif_reg->emif_sdram_ref_ctrl); + writel(regs->ref_ctrl, &emif_reg->emif_sdram_ref_ctrl_shdw); } /** |