[U-Boot] [PATCH] mx23: Put back RAM voltage level to its original value

[Fabio Estevam]

On Fri, Apr 26, 2013 at 3:16 PM, Marek Vasut <marex at denx.de> wrote:

>
> http://s8.postimg.org/dn7jhntut/imx233_olinuxino_maxi_2_5_V_rising.jpg check
> this, this is as much as I got from tsvetan so far, it's the VDDMEM ramping. I
> dunno what's that weird drop before it starts going from 1V5 to 2V5, but it's
> strange at best and I don't like it. I think that's also the source of our
> problems, the DRAM suffers undervolt and quickly afterwards is configured for
> regular operation ... I'd say check mx23_mem_setup_vddmem() and inspect the

Currently mx23_mem_setup_vddmem() does not clear ENABLE_ILIMIT
bit as recommended by the mx23 Reference Manual:

"Controls the inrush limit (~10mA) for the memory
supply voltage. Default is active. This should remain
active until the supply settles after enabling the linreg.
This should be disabled before accessing the memory."

FSL bootlets does clear this bit.

I did the same as FSL bootlets locally and this alone does not allowed
me to boot the kernel without bumping VDDMEM to 2.6V.

I can send a patch that clears ENABLE_LIMIT, after this one gets applied.