[U-Boot] [PATCH] exynos: Adjust the starting MIF voltage to 1.05v

Bernie Thompson bhthompson at chromium.org
Mon Apr 15 19:34:34 CEST 2013


Some Exynos5250 silicon may require 1.05v on the MIF to be stable, so to be
safe we can default to 1.05v instead of 1.00v. This can be set optimally later
in the boot process by the kernel.

The 0x6 value for 1.05v comes from the MAX77686 datasheet.

Signed-off-by: Bernie Thompson <bhthompson at chromium.org>
---
 board/samsung/smdk5250/smdk5250.c | 2 +-
 include/power/max77686_pmic.h     | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/board/samsung/smdk5250/smdk5250.c b/board/samsung/smdk5250/smdk5250.c
index 217c6df..2cea844 100644
--- a/board/samsung/smdk5250/smdk5250.c
+++ b/board/samsung/smdk5250/smdk5250.c
@@ -182,7 +182,7 @@ int power_init_board(void)
 
 	/* VDD_MIF */
 	if (pmic_reg_write(p, MAX77686_REG_PMIC_BUCK1OUT,
-						MAX77686_BUCK1OUT_1V)) {
+						MAX77686_BUCK1OUT_1_05V)) {
 		debug("%s: PMIC %d register write failed\n", __func__,
 						MAX77686_REG_PMIC_BUCK1OUT);
 		return -1;
diff --git a/include/power/max77686_pmic.h b/include/power/max77686_pmic.h
index fdc7ca9..1c374a9 100644
--- a/include/power/max77686_pmic.h
+++ b/include/power/max77686_pmic.h
@@ -157,6 +157,8 @@ enum {
 
 /* Buck1 1 volt value */
 #define MAX77686_BUCK1OUT_1V	0x5
+/* Buck1 1.05 volt value */
+#define MAX77686_BUCK1OUT_1_05V    0x6
 #define MAX77686_BUCK1CTRL_EN	(3 << 0)
 /* Buck2 1.3 volt value */
 #define MAX77686_BUCK2DVS1_1_3V	0x38
-- 
1.8.1.3



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