[U-Boot] mxs power initialization

[Ruud Commandeur]

Hi Stefan,

> -----Oorspronkelijk bericht-----
> Van: Stefan Wahren [mailto:stefan.wahren at i2se.com] 
> Verzonden: zaterdag 6 juni 2015 08:38
> Aan: Ruud Commandeur
> Onderwerp: Re: [U-Boot] mxs power initialization
> 
> Hi,
> 
> > Ruud Commandeur <RCommandeur at clb.nl> hat am 5. Juni 2015 um 
> 16:38 geschrieben:
> >
> >
> > Hi Everyone,
> >
> > I'm trying to make an i.mx28 board work with a Goldcap 
> attached to the 
> > Battery pin for RTC backup. This does not work out of the 
> box, but I 
> > found a number of useful tips to work with. Most of these 
> tips either 
> > refer to the imx bootlets or to code of "spl_power_init.c" 
> where the mxs power registers are configured.
> >
> > I do not use the imx bootlets, so spl_power_init was the 
> place to be I 
> > thought. However, it appears to be that this code is only 
> used if an 
> > SPL_BUILD is configured (am I correct?). But if SPL is not 
> used, which 
> > (code) part is used then to configure the imx power 
> registers (if there is any)?
> 
> i don't have answer to your question, but i want to mention 
> that i working on the mxs power driver for Linux mainline. 
> But my focus is on 5V only power supply. 
> 
> Beside the imx bootlets i took the power driver from the 
> Freescale downstream kernel as a source of knowledge [1]. May 
> be that is helpful.
> 
> Best regards
> Stefan
> 
> [1] -
> http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tr
> ee/drivers/power/mxs/linux.c?h=imx_2.6.35_maintain
> 

I was already wondering if the kernel would play a role here. For some reason this part was never mentioned when looking for these power issues. For some initial config bits this should not matter, but if actions should be taken on e.g. power-fail, this must reside in the kernel part.

Anyway: We use the mainline 3.10 LTS and obviously this does not have this mxs directory as for the 2.6.35 Freescale one. Would you happen to know if a similar (mxs-specific) driver should be present here?

P.S. I did put the u-boot-list on cc to inform about the answer(s). If the subject would change to kernel related subjects only, we could (or should) stop this I guess.

> >
> > Thanks in advance for your help,
> >
> > Ruud Commandeur
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