From: Davide Ciminaghi <ciminaghi@gnudd.com>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: sameo@linux.intel.com, rubini@gnudd.com,
giancarlo.asnaghi@st.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/8] sta2x11-mfd : add apb-soc regs driver and factor out common code
Date: Wed, 26 Sep 2012 18:31:45 +0200 [thread overview]
Message-ID: <20120926163145.GK10147@mail.gnudd.com> (raw)
In-Reply-To: <20120926150429.GQ4428@opensource.wolfsonmicro.com>
On Wed, Sep 26, 2012 at 04:04:29PM +0100, Mark Brown wrote:
> On Wed, Sep 26, 2012 at 04:56:15PM +0200, Davide Ciminaghi wrote:
> > On Tue, Sep 25, 2012 at 08:20:48PM +0100, Mark Brown wrote:
>
> > > Glancing at the diff here this looks a lot like regmap-mmio... not sure
> > > if it is or not, though.
>
> > that would be ideal, but I also need to deal with the common clock framework,
> > which doesn't support regmap: clk_register_divider(), clk_register_mux(),
> > clk_register_gate(), all take a void __iomem * to access clock control
> > registers, so as far as I can understand we can't use regmap, unless of
> > course we convert the common clock framework to regmap.
>
> The two should be able to coexist happily, regmap-mmio requires the
> caller to do the actual mapping and so long as you don't cache the
> relevant registers the two shouldn't interfere with each other.
>
Well, it just sounded not so clean to me having two ways for accessing the
same registers. The caller would be sta2x11-mfd in our case, while clock
registers are used by the common clock framework, so sta2x11-mfd should still
need to export some void __iomem * to make the clock framework happy, while
other potential users could go via regmap.
Oh, and there's another problem (I'm looking at the code right now, I had
forgotten about this): the clock framework also asks for a spinlock_t *.
Regmap has its own spinlock (or mutex), and I don't think it would be a
good idea trying to export it.
So, as far as I can understand at present, the best thing to do would be
adding regmap support to the clock framework, which wouldn't be trivial
because I guess we should keep compatibility with the present
clk_register_... api
Davide
next prev parent reply other threads:[~2012-09-26 16:32 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-12 10:22 [PATCH 0/8 RESEND] sta2x11-mfd patches ciminaghi
2012-09-12 10:22 ` [PATCH 1/8] sta2x11-mfd : add apb-soc regs driver and factor out common code ciminaghi
2012-09-25 19:20 ` Mark Brown
2012-09-26 14:56 ` Davide Ciminaghi
2012-09-26 15:04 ` Mark Brown
2012-09-26 16:31 ` Davide Ciminaghi [this message]
2012-09-26 16:49 ` Mark Brown
2012-09-27 8:39 ` Davide Ciminaghi
2012-09-27 8:56 ` Davide Ciminaghi
2012-09-27 13:41 ` Davide Ciminaghi
2012-09-27 13:49 ` Mark Brown
2012-09-28 8:43 ` Davide Ciminaghi
2012-09-28 10:52 ` Mark Brown
2012-09-27 14:13 ` Alan Cox
2012-09-28 15:29 ` Davide Ciminaghi
2012-09-12 10:22 ` [PATCH 2/8] sta2x11-mfd : add sta2x11_mfd_get_regs_data() function ciminaghi
2012-09-12 10:22 ` [PATCH 3/8] sta2x11-mfd : use defines for platform devices' names ciminaghi
2012-09-12 10:22 ` [PATCH 4/8] sta2x11-mfd : only add sta2x11_mfd if it hasn't already been added ciminaghi
2012-09-12 10:22 ` [PATCH 5/8] sta2x11-mfd : platform probe: don't mind about gpio platform data ciminaghi
2012-09-12 10:22 ` [PATCH 6/8] sta2x11-mfd : use one lock per device instead of one lock per mfd ciminaghi
2012-09-12 10:22 ` [PATCH 7/8] sta2x11-mfd : add defines for some sta2x11 sctl registers ciminaghi
2012-09-12 10:22 ` [PATCH 8/8] sta2x11-mfd : add myself to copyright ciminaghi
2012-09-16 21:25 ` [PATCH 0/8 RESEND] sta2x11-mfd patches Alessandro Rubini
-- strict thread matches above, loose matches on Subject: below --
2012-09-12 10:11 ciminaghi
2012-09-12 10:11 ` [PATCH 1/8] sta2x11-mfd : add apb-soc regs driver and factor out common code ciminaghi
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