Messages in this thread | | | Date | Fri, 3 Feb 2012 14:37:41 -0800 | From | Tony Lindgren <> | Subject | Re: [PATCH v2] pinctrl: pin configuration states |
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* Linus Walleij <linus.walleij@linaro.org> [120203 13:46]: > On Fri, Feb 3, 2012 at 12:03 AM, Tony Lindgren <tony@atomide.com> wrote: > > [Me] > >> +For simple systems that just configure the pins on boot and then forget about > >> +them, the first configuration table may be sufficient. However some systems > >> +may need to switch configuration states at runtime, and in that case the > >> +system may want to ground both pins by simply calling: > >> + > >> +ret = pinconf_activate_state("pinctrl-foo", "idle"); > > > > For dynamic changing of pin states during runtime we should not change > > the states based on string parsing. This is because some of these pins > > may need to be changed every time when entering and exiting idle. > > So pinmuxes get a handle back using a get/put pair, and > have enable/disable semantics as well. > > I avoided this for pin config since it would mean that you have > to keep some opaque cookie around, like we currently do with > pinmux. And pin config states are simpler in that you simply > move from one state to the other, no bookkeeping is involved. > > I never took into consideration that it may be a performance > issue to do that string parsing and you have a point there. > > So would you prefer something like: > > astat = pinconf_get_state("pinctrl-foo", "idle"); > istat = pinconf_get_state("pinctrl-foo", "idle"); > > pinconf_activate_state(astat); > pinconf_activate_state(istat); > ... > > If this is what people want I can sure do it like that instead.
OK that sounds good to me.
Regards,
Tony
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