Re: [patch 05/14] mfd: PCAP2 driver

From: Stefan Schmidt <stefan-OrPQZGeq07wqhVmZOOOmNx2eb7JE58TQ@public.gmane.org>
To: David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
Cc: Eric Miao <eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
	sameo-RWuK6r/cQWRpLGFMi4vTTA@public.gmane.org,
	linux-arm-kernel-xIg/pKzrS19vn6HldHNs0ANdhmdF6hFW@public.gmane.org,
	Daniel Ribeiro <drwyrm-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [patch 05/14] mfd: PCAP2 driver
Date: Sun, 23 Nov 2008 00:29:45 +0100	[thread overview]
Message-ID: <20081122232945.GB24437@datenfreihafen.org> (raw)
In-Reply-To: <200811221108.54331.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>

Hello.

On Sat, 2008-11-22 at 11:08, David Brownell wrote:
> On Saturday 22 November 2008, Daniel Ribeiro wrote:
> > Em Sáb, 2008-11-22 às 22:01 +0800, Eric Miao escreveu:
> > > On Sat, Nov 22, 2008 at 1:25 PM, David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org> wrote:
> > > > On Friday 21 November 2008, stefan-OrPQZGeq07wqhVmZOOOmNx2eb7JE58TQ@public.gmane.org wrote:
> > > >> Since the last submission we are also using the spi subsystem and
> > > >> pxa2xx-spi instead of ssp.c directly as before.
> > > >
> > > > I took a quick glance at this and it seemed like it should be
> > > > able to build without depending on PXA ... should certainly
> > > > not include <mach/ssp.h> or <mach/regs-ssp.h>, and it doesn't
> > > > look like it needs PXA-specific stuff like <mach/mfp-pxa27x.h>
> > > > either.
> > > >
> > > > It's also worth removing the reverse dependencies ("select X")
> > > > from Kconfig; they don't work very well for the things which
> > > > those dependencies rely on.
> > > >
> > > I'm wondering if it call fall into the regulator framework, along with
> > > a hwmon driver with its attributes being exported by sysfs.
> 
> Make it work like other MFD drivers, with child devices
> to encapsulate such functionality ... and drivers specific
> to those functionalities.
> 
> Such as a regulator framework driver, an RTC, and so on.

We do this already. pcap-rtc, pcap_ts and pcap_leds are later in this set.

As Daniel already pointed out. At the moment MMC is the only user of the voltage
regulator. We plan to add a regulator child device once more users come up.
(Pretty sure they will. :))

> > The ADC is also used by the touchscreen driver, and later will be used
> > for accessory detection (usb otg, charger, EMU (audio and uart on usb
> > port)).
> 
> ADC integration may be an interesting little puzzle.

It will. :/ 

At the moment we are working to have more of the basics done though.

The PXA dep is also almost gone. It's our aim to provide a generic driver here.

regards
Stefan Schmidt

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