From mboxrd@z Thu Jan  1 00:00:00 1970
From: Russell King - ARM Linux <linux@arm.linux.org.uk>
Subject: Re: [RFC PATCH 3/5] pxa: clean up the legacy SSP API
Date: Wed, 29 Apr 2009 08:27:06 +0100
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To: Daniel Ribeiro <drwyrm@gmail.com>
Cc: alsa-devel@alsa-project.org, Eric Miao <eric.y.miao@gmail.com>, Mark Brown <broonie@sirena.org.uk>, Philipp Zabel <philipp.zabel@gmail.com>, Paul Shen <bshen9@marvell.com>, linux-arm-kernel <linux-arm-kernel@lists.arm.linux.org.uk>
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On Tue, Apr 28, 2009 at 08:06:08PM -0300, Daniel Ribeiro wrote:
> Em Ter, 2009-04-28 =E0s 23:20 +0100, Russell King - ARM Linux escreveu:
> > On Thu, Apr 23, 2009 at 01:06:12PM +0800, Eric Miao wrote:
> > > Actually, due to the number of possible SSP configurations, it's quit=
e a
> > > difficult job to maintain an API that can be well re-used. The guidel=
ine
> > > here is to keep only a list of SSP devices and their basic informatio=
n,
> > > and it's up to the user driver (like SPI or Audio SSP) to configure t=
he
> > > SSP in a desired way.
> > =

> > Hmm, the LX battery driver uses this API for its rudimentary battery
> > communication channel with the PCON.
> > =

> > What are you suggesting as the replacement API?  Direct register access?
> =

> The SPI subsystem?

Can the SPI system cope with the other chip being the master of the
interface.  In other words, can SPI sit around primed for a transfer,
and notify the user of SPI that new data has arrived?

If not, the SPI subsystem is totally unsuitable for this.