[PATCH 2/4] wl1251: move power GPIO handling into the driver

Sebastian Reichel sre at ring0.de
Mon Oct 28 19:26:26 EDT 2013


Hi,

On Mon, Oct 28, 2013 at 12:23:54PM -0700, Mark Brown wrote:
> On Mon, Oct 28, 2013 at 07:29:52PM +0200, Grazvydas Ignotas wrote:
> 
> > When wl12xx family of chips is connected through SDIO, we already have
> > that pin set up as a regulator controlled with the help of mmc
> > subsystem. When time comes to communicate with the chip, mmc subsystem
> > sees this as yet another SD card and looks for associated regulator
> > for it, and the board file has that set up as a fixed regulator
> > controlling that pin (see pandora_vmmc3 in
> > arch/arm/mach-omap2/board-omap3pandora.c). To prevent poweroff after
> > first SDIO communications are over, pm_runtime calls are used in
> > drivers/net/wireless/ti/wl1251/sdio.c .
> 
> Is this actually controlling VMMC though, or is it some other control?
> If it's not controlling VMMC then it shouldn't say that it is.
> 
> > I don't know if something similar can be done done in SPI case, but
> > I'm sure this is not the first your-so-called regulator misuse.
> 
> It's not the first but that doesn't make controlling something other
> than a regulator through the regulator API any less broken.

I gave it a second try to find out details for this pin:

1. The pin is named PMEN in the Nokia N900 schematics
2. PMEN is described as "Power management enable - system shutdown"
   in a crippled datasheet of the wl1253, which I found in the internet.

I don't think this is supposed to be handled by the regulator API.

-- Sebastian
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