[U-Boot] [PATCH 11/13] i.MX28: Add battery boot components to SPL

[Marek Vasut]

Dear Lauri Hintsala,

> On 07/25/2012 10:28 PM, Marek Vasut wrote:
> > Dear Lauri Hintsala,
> > 
> >> On 07/25/2012 05:17 PM, Lauri Hintsala wrote:
> >>> Hi Marek,
> >>> 
> >>> On 05/02/2012 12:09 AM, Marek Vasut wrote:
> >>>> From: Marek Vasut <marek.vasut at gmail.com>
> >>>> 
> >>>> Signed-off-by: Marek Vasut <marek.vasut at gmail.com>
> >>>> Cc: Detlev Zundel <dzu at denx.de>
> >>>> Cc: Fabio Estevam <fabio.estevam at freescale.com>
> >>>> Cc: Stefano Babic <sbabic at denx.de>
> >>>> Cc: Wolfgang Denk <wd at denx.de>
> >>>> ---
> >>>> 
> >>>>    arch/arm/cpu/arm926ejs/mx28/spl_power_init.c |  100
> >>>> 
> >>>> +++++++++++++++++++++++---
> >>>> 
> >>>>    1 file changed, 92 insertions(+), 8 deletions(-)
> >>> 
> >>> This patch increases the power consumption about 250 mW (~50mA @ 5V). I
> >>> think it could be nice to disable LRADC after spl boot if it is not
> >>> really needed.
> >> 
> >> This happens only on our machine. The increase is only 25 mW (5mA) on
> >> mx28evk.
> > 
> > You tried with latest mainline?
> 
> Yes, I'm using v2012.07-rc2.
> 
> > Sure it's OK to disable LRADC afterwards, will you submit a patch please?
> 
> I just noticed the power was not eaten by LRADC. Power consumption is
> increasing because of a battery charger. The charger circuit is enabled
> even if the machine has no a battery connected to CPU.
> 
> I added debug code to see the status of the battery charger:
> 
> --- a/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
> +++ b/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
> @@ -1003,6 +1003,14 @@ void mx28_power_init(void)
> 
>   	writel(POWER_5VCTRL_PWDN_5VBRNOUT, &power_regs->hw_power_5vctrl_set);
> 
> +	/*
> +	power_regs->hw_power_charge_set = POWER_CHARGE_PWD_BATTCHRG;
> +	early_delay(1000);
> +	*/
> +
> +	serial_printf("Charger circuit: %s\n",
> +		power_regs->hw_power_charge & 
POWER_CHARGE_PWD_BATTCHRG?"down":"up");
> +
>   	early_delay(1000);
>   }
> 
> After disabling battery charger at the end of power init 25 mW power
> leak has been gone. Tested with mx28evk rev D. Is there any reason to
> enable the charger without a battery?

No, no reason at all, disable it in case you're not running from battery. But 
please cross check with imx bootlets.

> Lauri

Best regards,
Marek Vasut