+ Linus W. (pinctrl maintainer) Dmitry Torokhov <dmitry.torok...@gmail.com> writes:
> Hi Hebbar, > > On Fri, May 31, 2013 at 03:43:00PM +0530, Hebbar Gururaja wrote: >> By optionally putting the pins into sleep state in the suspend [or in >> runtime_suspend] callback we can accomplish two things. >> - One is to minimize current leakage from pins and thus save power, >> - second, we can prevent the IP from driving pins output in an >> uncontrolled manner, which may happen if the power domain drops the >> domain regulator. >> >> These states can be specified in the DT blob and corresponding driver >> can pick these states during probe & set the related values during >> idle/suspend. >> >> Not all drivers support/has idle state. Drivers like i2c, spi, mmc has >> idle states and hence these drivers are updated to support all the >> three states >> - default : during regular operation >> - idle : when the module is in idle state >> - sleep : when the module is in suspend state >> >> For those drivers which doesn't support/have idle state (at least at >> the moment), only default & sleep state is added. > > As with the original introduction of pinctrl states my question is: "Can > all of this be handled in the driver/bus core instead of adding a lot > of boilerplate code to the individual drivers". Yes, I had the same thought. What's being handled here are either events related to runtime PM (runtime suspend, runtime resume) or system PM (suspend/resume) so seems appropriat to handle them in the PM core. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
