Re: N900 DT

From: Sebastian Reichel
Date: Fri Oct 25 2013 - 20:25:54 EST


Hi Pali,

On Fri, Oct 25, 2013 at 08:39:40PM +0200, Pali Rohár wrote:
> Now I found this patch and it looks like it will be in mainline
> kernel. And after that it could be simple to listen for needed
> events from isp driver in my bq driver (without touching isp).
>
> https://lkml.org/lkml/2013/7/25/204
>
> Can you look at isp1704 driver for DT support? I think that only
> one gpio needs to be passed to driver from board data.

I had a quick overview over Jenny's patchset [0] (the patch you
referenced is part of a bigger patchset). I don't think the
scenario found in the Nokia N900 is covered by it, but probably
now is the time to change it :)

So for everybody new to this thread:

Multiple chips are involved in the charging of the Nokia N900
battery:

bq27200: This chip is used for reading battery status. AFAIK
it's not directly involved in charging the battery.
bq24150a: This chip takes care of actually charging the battery.
It has no clue about USB related stuff. The maximum
current it draws can be configured, though.
isp1704: USB charger detector. This chip is used to detect how
much current may be used by the bq24150a chip.
rx51-temp: Analog temperature sensor for the battery, which is
connected via an analog-digital-converter.

The question is how to connected these driver with each other
if device tree is used to boot the system. Any suggestions?

[0] http://thread.gmane.org/gmane.linux.kernel/1377608

-- Sebastian

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