Subject: devicetree support for efikasb

From: [email-masked] (Sascha Hauer)
Date: Wed, 19 Dec 2012 09:56:43 +0100

On Tue, Dec 18, 2012 at 11:30:17AM +0100, Arnaud Patard wrote:
> Arnaud Patard (Rtp) <[email-masked]> writes:
> Hi,
> 
> 
> >>
> >>> 
> >>> >
> >>> > I'm not posting the patches here since I do not consider them ready, but
> >>> > for everyone interested you can pull the following git tree. I have no
> >>> > idea if the patches work together with the preinstalled U-Boot, I use
> >>> > barebox on the Smartbook.
> >>> 
> >>> I've (very quickly) tested it yesterday and it didn't even boot. I've
> >>> yet to look at the serial port output to check if it's a problem on my
> >>> side or a bug in the kernel.
> >>
> >> Do you mean barebox doesn't boot or the kernel doesn't boot?
> >
> > No idea. All I get is a black screen, so I need to look at the serial
> > output. Oh, it's uboot not barebox btw. Sorry for the confusion.
> 
> After digging a little bit, turns out that someone failed to make sure
> that clocks are enabled before reading/writing some
> registers. imx51_ipu_mipi_setup() is called very early in the boot and
> it's way before the clocks are enabled. So, as the clock is not enabled
> when booting on my sb, it's freezing hard. A quick hack to move the call
> to the end of mx51_clocks_init() allows to boot.

Shawn already noticed this. A fix should appear soon in mainline.

> 
> Then, I'm getting a oops. i2c doesn't seem to work (maybe related to
> Matt and Steev remarks about pinctrl settings) so the edid is not found
> and when the mtl017 driver is trying to fall back, it falls back the the
> edid which may be provided by the dts. As it's not the case, it's
> crashing at the memcmp() call. With a new test to check that, I can boot
> on my mmc.
> 
> PATA is detected too but usb doesn't detect anything on the bus.
> 
> Next steps will probably be something like checking mtl017/lvds,lcd
> gpios/regulators/pinctrl and then look at usb.

This is probably because I'm using barebox. The i2c pinmux is probably
configured in the bootloader correctly. That should be easy to fix.
USB may be more work though...

> 
> Oh, btw, the smartbook have only 512M of ram, not 1G so you need to fix
> that in your dts file.

Will do. The bootloader fixes that for me currently, so I didn't realize
this.

Sascha

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