From mboxrd@z Thu Jan  1 00:00:00 1970
From: k.kozlowski@samsung.com (Krzysztof Kozlowski)
Date: Tue, 21 Oct 2014 12:14:36 +0200
Subject: [PATCH 2/2] ARM: dts: exynos4412-trats: Add suspend configuration
 for max77686 regulators
In-Reply-To: <54462EB2.2070302@collabora.co.uk>
References: <1413879912-26606-1-git-send-email-k.kozlowski@samsung.com>
 <1413879912-26606-3-git-send-email-k.kozlowski@samsung.com>
 <54461FC0.9020904@samsung.com> <1413883424.26980.7.camel@AMDC1943>
 <54462EB2.2070302@collabora.co.uk>
Message-ID: <1413886476.26980.16.camel@AMDC1943>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On wto, 2014-10-21 at 12:00 +0200, Javier Martinez Canillas wrote:
> Hello Krzysztof,
> 
> On 10/21/2014 11:23 AM, Krzysztof Kozlowski wrote:
> >> >  
> >> >  				ldo9_reg: ldo9 {
> >> > @@ -295,7 +311,9 @@
> >> >  					regulator-name = "CAM_ISP_MIPI_1.2V";
> >> >  					regulator-min-microvolt = <1200000>;
> >> >  					regulator-max-microvolt = <1200000>;
> >> > -					regulator-mem-idle;
> >> > +					regulator-state-mem {
> >> > +						regulator-on-in-suspend;
> >> 
> >> CAM_ISP_MIPI_1.2V is used for camera, I think this regulator should turn off in suspend state
> >> because camear could not be used in suspend state.
> > 
> > LDO9 does not support off in suspend mode controlled by PWRREQ. It
> > supports only switching to low power mode if PWRREQ level goes low.
> > 
> > Thus the driver does not provide set_suspend_enable or
> > set_suspend_disable for LDO0. Do you want to add such function to the
> > max77686 driver which will explicitly disable the regulator (write 0x0
> > to control reg)?
> > 
> > 
> 
> I think for those regulators you can just use regulator_disable_regmap()
> as the .set_suspend_disable function handler?

Sure... but this does not solve the philosophical problem - this is not
a special suspend configuration. It is disabling the regulator manually,
from regulator core code. Instead probably the camera driver should
disable the regulator in suspend callback.

Another point - I think none of other regulators do this way.

Best regards,
Krzysztof