Messages in this thread | | | Date | Fri, 19 Aug 2011 13:59:00 +0200 | Subject | Re: [PATCH 1/2] drivers: create a pinmux subsystem v3 | From | Linus Walleij <> |
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On Sat, Jul 9, 2011 at 12:23 PM, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote: > On Mon, Jun 13, 2011 at 01:57:36PM -0600, Grant Likely wrote: >> On Mon, Jun 13, 2011 at 10:58 AM, Linus Walleij >> >> I would *strongly* recommend against individual device drivers >> accessing the pinmux api. This is system level configuration code, >> and should be handled at the system level. > > There can also be advantages to putting the pin into the designed mode > without the driver being loaded from the electrical point of view. For > example, selecting appropriate pull values for pads can cut down on > power consumption.
Since the pin control subsystem is reference counting wrt mux settings, one does not exclude the other. So for example a driver may or may not grab a certain set-up of pins and the core platform may do the same, but when they start to request different conflicting things the subsystem will complain, as is apropriate.
So this is a very pure driver framework, without policy, it just does what it's told, and will prevent undefined and impossible settings. Atleast that's the idea.
Thanks, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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