diff mbox

[U-Boot,v2,08/15] powerpc/km8321: define CONFIG_SYS_DDRCDR

Message ID 1447754018-12365-9-git-send-email-valentin.longchamp@keymile.com
State Accepted
Delegated to: Tom Rini
Headers show

Commit Message

Valentin Longchamp Nov. 17, 2015, 9:53 a.m. UTC
On the km8321 boards is CONFIG_SYS_DDRCDR not defined, which leads to
the DDRCDR not being configured at startup and still containing the
reset value.

The required settings for our km8321 hardware designs are different than
the reset value and must be set with CONFIG_SYS_DDRCDR, that is used
by mpc83xx's cpu_init_f function at early CPU initialization.

The important settings are the DDR2 internal voltage level and the
half-strength "drivers".

In our case where the DRAM chips are soldered on board and the routing
for these signals under control, half-strength is sufficient as a few
measurements done in the lasts have shown. Since all the hardware
qualification tests have been performed with half strength, the nominal
strength settings are removed in favor of the default reset half
strength settings.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>

---

Changes in v2:
- Squashed commit 9/17 and 10/17 together into a single commit

 include/configs/km/km8321-common.h | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Tom Rini Nov. 18, 2015, 10:36 p.m. UTC | #1
On Tue, Nov 17, 2015 at 10:53:31AM +0100, Valentin Longchamp wrote:

> On the km8321 boards is CONFIG_SYS_DDRCDR not defined, which leads to
> the DDRCDR not being configured at startup and still containing the
> reset value.
> 
> The required settings for our km8321 hardware designs are different than
> the reset value and must be set with CONFIG_SYS_DDRCDR, that is used
> by mpc83xx's cpu_init_f function at early CPU initialization.
> 
> The important settings are the DDR2 internal voltage level and the
> half-strength "drivers".
> 
> In our case where the DRAM chips are soldered on board and the routing
> for these signals under control, half-strength is sufficient as a few
> measurements done in the lasts have shown. Since all the hardware
> qualification tests have been performed with half strength, the nominal
> strength settings are removed in favor of the default reset half
> strength settings.
> 
> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>

Applied to u-boot/master, thanks!
diff mbox

Patch

diff --git a/include/configs/km/km8321-common.h b/include/configs/km/km8321-common.h
index 058b0ab..b2e68e3 100644
--- a/include/configs/km/km8321-common.h
+++ b/include/configs/km/km8321-common.h
@@ -65,6 +65,12 @@ 
 	HRCWH_BIG_ENDIAN | \
 	HRCWH_LALE_NORMAL)
 
+#define CONFIG_SYS_DDRCDR (\
+	DDRCDR_EN | \
+	DDRCDR_PZ_MAXZ | \
+	DDRCDR_NZ_MAXZ | \
+	DDRCDR_M_ODR)
+
 #define CONFIG_SYS_DDR_CS0_BNDS		0x0000007f
 #define CONFIG_SYS_DDR_SDRAM_CFG	(SDRAM_CFG_SDRAM_TYPE_DDR2 | \
 					 SDRAM_CFG_32_BE | \