[U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro

[Marek Vasut]

On Sunday, June 15, 2014 at 03:11:56 PM, Peter Schumann wrote:
> This patch makes it possible to boot from battery on olinuxino Boards
> from Olimex.
> 
> We should not set DOUBLE_FETS in HW_POWER_MINPWR, it makes my system
> reset with in seconds while running on battery power.
> 
> Also  mxs_power_enable_4p2() should not be called if running from
> battery. It switches VDDD and VDDA to LinReg mode and than turns off
> the VDDIO DCDC supply. At this point the system resets.
> If we run on battery this is no good idea because the LinRegs are
> chained behind VDDIO and battery voltage seems not enough to power
> the system from LinRegs.
> Also is the power system already running on DCDC after BootROM hands
> over to u-boot, so no sense in switching back to LinRegs.
> 
> Signed-off-by: Peter Schumann <peter.schumann at jeepxj.de>

+CC Fabio, I'd like to see his take on this too.

Best regards,
Marek Vasut