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From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/2] mfd: max8925: request resource region
Date: Wed, 9 May 2012 12:43:13 +0000	[thread overview]
Message-ID: <201205091243.13206.arnd@arndb.de> (raw)
In-Reply-To: <20120508153155.GW15893@opensource.wolfsonmicro.com>

On Tuesday 08 May 2012, Mark Brown wrote:
> On Tue, May 08, 2012 at 02:44:30PM +0000, Arnd Bergmann wrote:
> 
> > How about a IORESOURCE_REGMAP type then with the following semantics:
> 
> The trick is allocating a bit for that flag, though I was thinking
> earlier on we might be able to get away with carving it out of the bus
> specific bits since I think anything using this wouldn't normally be
> using resources for anything else except interrupts.  It does mean that
> the resource type doesn't do the right thing though.

Right, or we could try to kill IORESOURCE_BUS, which is hardly used
anywhere and the users either get it wrong (bfin net2272), use it
only in one file (acpi, broadcom-pci) or only for printing the
contents (pnp).

> > Each struct regmap gets an embedded resource that gets a unique
> > range in the IORESOURCE_REGMAP space using allocate_resource,
> > and each device using that can have its own sub-resources registered
> > to that.
> 
> > Then we add a helper function that pulls out the regmap from the resource
> > using something like container_of(res->parent, struct regmap, resource)
> > and calculates the register number by subtracting the parent->start from
> > res->start.
> 
> That feels complicated with the subtraction there, but modulo that this
> is roughly what's happening now.  We would I think want this to work for
> non-regmap users too, it's not yet clear that every device with
> registers is going to fit into regmap (though it's looking more likely
> as things go on).

I think the subtraction in some form is needed if you want to register
the resources, to guarantee that they are non-conflicting. Registering
them has the advantage that we can print them in a similar way to what
we do for /proc/{ioports,iomem}.

	Arnd

  reply	other threads:[~2012-05-09 12:43 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-07  3:10 [PATCH 1/2] mfd: max8925: request resource region Haojian Zhuang
2012-05-07  3:10 ` [PATCH 2/2] ARM: mmp: add io head file Haojian Zhuang
2012-05-07  9:23   ` Arnd Bergmann
2012-05-07  7:58 ` [PATCH 1/2] mfd: max8925: request resource region Russell King - ARM Linux
2012-05-07  8:18   ` Haojian Zhuang
2012-05-07  8:59     ` Russell King - ARM Linux
2012-05-07  9:01   ` Mark Brown
2012-05-07  9:08     ` Russell King - ARM Linux
2012-05-07  9:47       ` Mark Brown
2012-05-07 10:14         ` Arnd Bergmann
2012-05-07 10:23           ` Haojian Zhuang
2012-05-07 11:21             ` Arnd Bergmann
2012-05-07 11:29               ` Mark Brown
     [not found]                 ` <201205071319.48768.arnd@arndb.de>
2012-05-07 14:02                   ` Samuel Ortiz
2012-05-07 14:15                   ` Mark Brown
2012-05-07 15:15                     ` Arnd Bergmann
2012-05-07 15:28                       ` Mark Brown
2012-05-07 10:37           ` Mark Brown
     [not found]             ` <201205071314.51886.arnd@arndb.de>
2012-05-07 14:06               ` Mark Brown
2012-05-07 15:09                 ` Arnd Bergmann
2012-05-07 15:17                   ` Mark Brown
2012-05-07 19:26                     ` Arnd Bergmann
2012-05-07 19:58                       ` Mark Brown
2012-05-08  8:17                       ` Mark Brown
2012-05-08 14:44                         ` Arnd Bergmann
2012-05-08 15:31                           ` Mark Brown
2012-05-09 12:43                             ` Arnd Bergmann [this message]
2012-05-09 14:13                               ` Mark Brown
2012-05-09 14:19                                 ` Arnd Bergmann
2012-05-09 14:42                                   ` Mark Brown
2012-05-09 15:03                                     ` Arnd Bergmann
2012-05-09 15:28                                       ` Mark Brown
2012-05-09 16:27                                         ` Arnd Bergmann
2012-05-09 16:18                                 ` Russell King - ARM Linux
2012-05-09 16:30                                   ` Mark Brown
2012-05-09 16:07                               ` Russell King - ARM Linux
2012-05-09 16:26                                 ` Arnd Bergmann
2012-05-09 16:27                                   ` Russell King - ARM Linux
2012-05-07 18:57             ` Russell King - ARM Linux
2012-05-07 19:27               ` Mark Brown
2012-05-07  8:12 ` Samuel Ortiz

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