Messages in this thread | | | Date | Wed, 17 Jul 2013 19:56:22 +0300 | From | Grygorii Strashko <> | Subject | Re: [PATCH 2/3] ARM: OMAP2+: omap_device: add pinctrl handling |
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On 07/17/2013 06:38 PM, Tony Lindgren wrote: > * Grygorii Strashko <grygorii.strashko@ti.com> [130717 04:49]: >> Before switching to DT pinctrl states of OMAP IPs have been handled by hwmod >> framework. After switching to DT-boot the pinctrl handling was dropped from >> hwmod framework and, as it was recommended, OMAP IP's drivers have to be updated >> to handle pinctrl states by itself using pinctrl_pm_select_xx() helpers >> (see http://lists.infradead.org/pipermail/linux-arm-kernel/2013-June/173514.html) >> >> But this is not right for OMAP2+ SoC where real IPs state is controlled >> by omap_device core which enables/disables modules & clocks actually. > > I'm not convinced we should try to handle this in a generic way > as only some devices need dynamic remuxing of some pins. > >> For example, if OMAP I2C driver will handle pinctrl state during system wide >> suspend the following issue may occure: >> - suspend_noirq - I2C device can be still active because of PM auto-suspend >> |-_od_suspend_noirq >> |- omap_i2c_suspend_noirq >> |- PINs state set to SLEEP >> |- pm_generic_runtime_suspend >> |- omap_i2c_runtime_suspend() >> |- PINs state set to IDLE <--- *oops* PINs state is IDLE and not SLEEP >> |- omap_device_idle() >> |- omap_hwmod_idle() >> |- _idle() >> |- disbale module (sysc&clocks) > > And in this example you are assuming that you need separate idle and > sleep states, which is not true at least for most cases I've seen.
I don't need both states (at least right now) :), but - if any OMAP2+ driver will have two states defined: "idle" and "sleep" - and if it will try to manage them from drivers callbacks only using pure calls to pinctrl_pm_select_xx() helpers
the "idle" state will be selected during suspend and *not* "sleep".
> > It is possible that am33xx needs separate idle and sleep states, but > most likely only for some pins. For omap[345] we can get away with > just the default state for most cases. >
In case, if only "default" state is defined for device - nothing will be done by OMAP device framework for it (I mean any call to pinctrl_pm_select_xx() will do nothing - it just checks that there is no state and returns 0).
> Regards, > > Tony >
Regards, - grygorii
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