Setting PMIC regulator voltage in U-Boot SPL, to specify DDR voltage

[Chris Richardson]

Hi,

I'm working on a board with an Allwinner H6 that uses
an AXP805 PMIC.

I'm using DDR3-1600, which requires 1.4V.  In my boot.cmd, I am doing the
following -

regulator dev dcdce
regulator value 1400000
regulator enable

To set the voltage to 1.4V in U-Boot proper, this avoids memory issues, such as random resets.

However what I would like to do is to set the regulator voltage in U-Boot SPL, so that
the voltage would be set ideally before memory size detection etc.

To do this I thought I needed to enable features such as 'CONFIG_SPL_DM'.
I've listed the main configuration I used below -

...
CONFIG_DM=y
CONFIG_SPL=y
CONFIG_SPL_DM=y

CONFIG_MACH_SUN50I_H6=y
CONFIG_SUNXI_DRAM_H6_DDR3_1333=y
CONFIG_DRAM_CLK=648

CONFIG_SYS_I2C_MVTWSI=y
CONFIG_SPL_I2C=y
CONFIG_DM_I2C=y
CONFIG_CMD_I2C=y

CONFIG_POWER=y
CONFIG_POWER_I2C=y
CONFIG_PMIC_CHILDREN=y
CONFIG_DM_PMIC=y
CONFIG_SPL_DM_PMIC=y
CONFIG_PMIC_AXP=y
CONFIG_SPL_PMIC_AXP=y
CONFIG_CMD_PMIC=y
CONFIG_CMD_REGULATOR=y
CONFIG_AXP_PMIC_BUS=y

CONFIG_DM_REGULATOR=y
CONFIG_SPL_DM_REGULATOR=y
CONFIG_CMD_REGULATOR=y
CONFIG_REGULATOR_AXP=y
CONFIG_SPL_REGULATOR_AXP=y
...

Currently I am overflowing SRAM -

aarch64-linux-gnu-ld.bfd: address 0x2a868 of u-boot-spl section `.text' is not within region `.sram'
aarch64-linux-gnu-ld.bfd: u-boot-spl section `.rodata' will not fit in region `.sram'
aarch64-linux-gnu-ld.bfd: address 0x2a868 of u-boot-spl section `.text' is not within region `.sram'
aarch64-linux-gnu-ld.bfd: address 0x2a868 of u-boot-spl section `.text' is not within region `.sram'
aarch64-linux-gnu-ld.bfd: region `.sram' overflowed by 22296 bytes

I'm just wondering if anyone has any suggestions?

Also I wasn't sure, if I can get the AXP PMIC supported in SPL, how I'd set the voltage in U-Boot SPL?

Many thanks
Chris
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