Re: [PATCH/RFC 7/7] wl12xx: add sdio support

[Bob Copeland <me@bobcopeland.com>]

On Sat, Jun 13, 2009 at 10:09:08PM +0200, Pierre Ossman wrote:
> On Sat, 13 Jun 2009 19:00:41 +0300
> Kalle Valo <kalle.valo@iki.fi> wrote:
> 
> That doesn't make sense. If the card doesn't have power then there will
> be no device and no interface to bring up.

For SPI, you would register the platform driver with the SPI subsystem,
which gives you the ability to call the set_power callback at any time.
There's not a problem starting the driver if there is no device (as I
understand it, SPI is so simple there's no way to probe the bus anyway).

It would be nice to allow the SDIO driver to similarly invoke the
platform->set_power() callback at interface up/down time (that's why
there's wl12xx_sdio_set_power() which does nothing right now).  However,
then the device will disappear from the bus...

> +	wifi_ctrl->set_power(1);	/* Power On */

Except for the problems outlined above, this would be invoked from
wl12xx_sdio_set_power().  But without it being up at start, probe()
won't work anyway.  So it sounds like wl12xx_sdio_set_power() will
have to be a no-op for sdio devices unless there's some register
we can poke on the chip to put it to sleep.

> I think this should be somewhere under arch/ in the board setup code,
> where currently you have some code adding the "msm_wifi" platform
> device.

Yeah, in fact I tried that a while ago but something didn't work right,
some ordering issue perhaps.  I'll try again.

-- 
Bob Copeland %% www.bobcopeland.com