Patchwork [U-Boot] am33xx:ddr:Fix config_sdram to work for all DDR

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Submitter Tom Rini
Date March 8, 2013, 5:40 p.m.
Message ID <1362764458-15979-1-git-send-email-trini@ti.com>
Download mbox | patch
Permalink /patch/226180/
State Accepted
Delegated to: Tom Rini
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Comments

Tom Rini - March 8, 2013, 5:40 p.m.
From: Steve Kipisz <s-kipisz2@ti.com>

The original write to sdram_config is correct for DDR3 but incorrect
for DDR2 so SPL was hanging. For DDR2, the write to sdram_config
should be after the writes to ref_ctrl. This was working for DDR3
because there was a write of 0x2800 to ref_ctrl before a write
to sdram_config.

Tested on: GP EVM 1.1A (DDR2), GP EVM 1.5A (DDR3),
           Beaglebone A6 (DDR2), Beagleone Blacd A4A (DDR3)

Signed-off-by: Steve Kipisz <s-kipisz2@ti.com>
---
 arch/arm/cpu/armv7/am33xx/ddr.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
Tom Rini - March 26, 2013, 2:52 p.m.
On Fri, Mar 08, 2013 at 07:40:58AM -0000, Tom Rini wrote:

> From: Steve Kipisz <s-kipisz2@ti.com>
>
> The original write to sdram_config is correct for DDR3 but incorrect
> for DDR2 so SPL was hanging. For DDR2, the write to sdram_config
> should be after the writes to ref_ctrl. This was working for DDR3
> because there was a write of 0x2800 to ref_ctrl before a write
> to sdram_config.
>
> Tested on: GP EVM 1.1A (DDR2), GP EVM 1.5A (DDR3),
>            Beaglebone A6 (DDR2), Beagleone Blacd A4A (DDR3)
>
> Signed-off-by: Steve Kipisz <s-kipisz2@ti.com>

Applied to u-boot-ti/master (and already pulled into u-boot-arm),
thanks!

--
Tom

Patch

diff --git a/arch/arm/cpu/armv7/am33xx/ddr.c b/arch/arm/cpu/armv7/am33xx/ddr.c
index 448cc40..7932a39 100644
--- a/arch/arm/cpu/armv7/am33xx/ddr.c
+++ b/arch/arm/cpu/armv7/am33xx/ddr.c
@@ -54,10 +54,13 @@  void config_sdram(const struct emif_regs *regs)
 		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);
 	}
-	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);
+	writel(regs->sdram_config, &emif_reg->emif_sdram_config);
 }
 
 /**