diff options
| author | Tom Rini <trini@ti.com> | 2013-02-26 16:35:33 -0500 |
|---|---|---|
| committer | Tom Rini <trini@ti.com> | 2013-02-26 16:37:36 -0500 |
| commit | 5e62f0491069d9d4d96845d50dd3f2847ad696a9 (patch) | |
| tree | 11dfc671c770305301ebce43896dfafef4f5945e | |
| parent | 44e60614de5aa201f3f72d912003699c4a5342f4 (diff) | |
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>
| -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 fd9fc4a720..448cc40157 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); } /** |