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From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: Pinmux bindings proposal V2
Date: Fri, 27 Jan 2012 09:37:32 -0800	[thread overview]
Message-ID: <20120127173732.GJ13504@atomide.com> (raw)
In-Reply-To: <CAPnjgZ2EkvTMsOkWyf4pfwRpvcvYs=WaKy5Gi8fdkAUQmvt=ig@mail.gmail.com>

* Simon Glass <sjg@chromium•org> [120127 07:12]:
> 
> On Thu, Jan 26, 2012 at 6:21 PM, Tony Lindgren <tony@atomide•com> wrote:
> >
> > Maybe we need two bindings: A minimal subset of what Stephen is suggesting
> > that can handle 95% of the muxes with minimal overhead, then what you're
> > suggesting for the few muxes that need multiple states?
> 
> Perhaps that would work, it certainly deals nicely with making the
> rare cases less ugly if indeed they are rare. Of course a single
> binding that is not too ugly and still reasonably efficient would be
> best.
> 
> I will have a think about this a bit more and see if anything leaps
> out. It's quite an interesting problem...

Just to try to recap what has come up so far:

1. We need to avoid bloating things for basic cases to initialize
   several hundred pins.

2. Some muxes need to define multiple states.

3. We need to pass a flag for each mux to know whether or
   not it can be freed after init.

So how about let's do separate static and dynamic bindings,
something like this:

	/*
	 * Static init time only mux where
	 * we only specify phandle to driver
	 * and, offset of the mux, and the value.
	 * These pins are discarded after init.
	 *
	 * Format:	  mux_ctrl      offset value
	 */
	pinctrl-static = <&pmx_driver1  0x0020 0x1245
			   &pmx_driver2 0x0022 0x6578>;

	/*
	 * Dynamic mux where the mux is kept around after
	 * init and multiple states can be defined for
	 * a mux as a subnode of the pinmux controller.
	 *
	 * Format:	   mux_phandle   initial state
	 */ 
	pinctrl-dynamic = <&pmx_sdhci    PMX_STATE_ENABLED
			   &pmx_ehci_xcv PMX_STATE_ENABLED>;

This would make pinctrl-static binding follow the same
standard as GPIO binding and can be parsed easily with
of_parse_phandle_with_args.

Then for pinctrl-dynamic we can make a custom parser,
and the binding can follow the more readable format as
Simon posted.

Regards,

Tony

  reply	other threads:[~2012-01-27 17:37 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-20 22:22 Pinmux bindings proposal V2 Stephen Warren
2012-01-23 21:00 ` Tony Lindgren
2012-01-23 23:08   ` Stephen Warren
2012-01-24  1:20     ` Tony Lindgren
2012-01-24 22:29       ` Stephen Warren
2012-01-25  0:04         ` Tony Lindgren
2012-01-26 19:33           ` Stephen Warren
2012-01-27  2:08             ` Tony Lindgren
2012-01-27  6:57               ` Shawn Guo
2012-01-27 17:05                 ` Tony Lindgren
2012-01-30  1:56                   ` Shawn Guo
2012-01-30 17:20                     ` Tony Lindgren
2012-01-31  1:32                       ` Shawn Guo
2012-01-31  2:29                         ` Tony Lindgren
     [not found]                           ` <C8443D0743D26F4388EA172BF4E2A7A93176CAC6@DBDE01.ent.ti.com>
2012-01-31 17:05                             ` Reg pinmux driver for OMAP based SoC- AM335X Tony Lindgren
2012-02-01 10:04                               ` Hiremath, Vaibhav
2012-02-01 18:14                                 ` Tony Lindgren
2012-02-03 20:57                                   ` Tony Lindgren
2012-02-01 11:00                               ` Mohammed, Afzal
2012-02-01  5:36                           ` Pinmux bindings proposal V2 Shawn Guo
2012-01-27 17:36               ` Stephen Warren
2012-01-27 17:42                 ` Tony Lindgren
2012-01-26  9:36   ` Shawn Guo
2012-01-26 17:51     ` Tony Lindgren
2012-01-27  7:19       ` Shawn Guo
2012-01-27 17:16         ` Tony Lindgren
2012-01-30  2:10           ` Shawn Guo
2012-01-30 17:43             ` Tony Lindgren
2012-01-31  1:07               ` Shawn Guo
2012-01-26  9:24 ` Shawn Guo
2012-01-26 17:42 ` Simon Glass
2012-01-27  2:21   ` Tony Lindgren
2012-01-27 15:43     ` Simon Glass
2012-01-27 17:37       ` Tony Lindgren [this message]
2012-01-27 17:51         ` Stephen Warren
2012-01-27 18:10           ` Tony Lindgren
2012-01-30  3:27           ` Shawn Guo
2012-01-30  3:13       ` Shawn Guo
2012-01-30 17:49         ` Tony Lindgren
2012-01-27 17:38     ` Stephen Warren
2012-01-27 17:29   ` Stephen Warren
2012-01-30  2:31     ` Shawn Guo
2012-02-01 14:35 ` Shawn Guo
2012-02-02 18:36   ` Stephen Warren
2012-02-02 20:07     ` Dong Aisheng
2012-02-03 14:02       ` Shawn Guo
2012-02-03 17:21         ` Dong Aisheng
2012-02-03 17:32       ` Tony Lindgren
2012-02-03 18:13         ` Dong Aisheng
2012-02-03 21:05           ` Tony Lindgren
2012-02-04 16:55             ` Dong Aisheng
2012-02-04 17:15               ` Tony Lindgren
2012-02-03  8:46     ` Shawn Guo
2012-02-13 19:58 ` Stephen Warren

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