Date: Fri, 31 May 2013 10:04:37 -0700
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Hebbar Gururaja <gururaja.hebbar@ti.com>
Cc: khilman@linaro.org, grant.likely@linaro.org, linus.walleij@linaro.org,
        rob.herring@calxeda.com,
        davinci-linux-open-source@linux.davincidsp.com,
        devicetree-discuss@lists.ozlabs.org,
        linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk,
        linux-kernel@vger.kernel.org, vaibhav.bedia@ti.com,
        sudhakar.raj@ti.com
Subject: Re: [PATCH 00/11] drivers: Add Pinctrl PM support
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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".

Thanks.

-- 
Dmitry
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