Powering i.MX28 from the integrated linear regulators

JHY · ‎10-29-2014

My i.MX28 custom board is powered from linear regulators, VDD5V source only system..

I edit spl_power_init.c in u-boot, but it does not work, just repeats booting fail and restarting .

HW_POWER registers are below now.

v5ctrl (2403F592),

dcdc4p2 (A080001F),

vddd (00F00710),

vdda (000F070C),

vddio (00070406)

Is there mistakes on setting registers or additional to do?

Best regarts.

igorpadykov · ‎10-29-2014

Hi JHY

it is not possible to say what setting are correct, since

for each board they will be different. You can try to add

printfs to code or run with jtag and check where brownout

(BO_OFFSET in HW_POWER_VDDIOCTRL and other registers) occurs

in code. You may wish to check i.MX28 EVK codes

L2.6.35_10.12_5V_SUPPLY_PATCH : Linux patch for i.MX28 SDK 2010.12 to

add the most robust support possible for a VDD5V or DCDC_BATT only configuration..

L2.6.35_1.1.0_ER_SOURCE : i.MX28 Linux 2.6.35 Source Code Files and documentation.

one can also try IMX_OBDS : On-Board Diagnostic Suit for the i.MX28.

Best regards

igor