i.MX31 suspend and VSTBY question

Nguyen Dinh-R00091 R00091 at freescale.com
Mon Mar 21 12:43:34 EDT 2011

Hi Helmut,

>-----Original Message-----
>From: linux-arm-kernel-bounces at lists.infradead.org [mailto:linux-arm-kernel-
>bounces at lists.infradead.org] On Behalf Of Helmut Raiger
>Sent: Monday, March 21, 2011 11:20 AM
>To: linux-arm-kernel at lists.infradead.org
>Subject: Re: i.MX31 suspend and VSTBY question
>Thanks for your response! Your CCMR register setting does not change the
>behaviour on my board.
>A few questions:
>1) What kernel version are you running?

Unfortunately our last fully tested version was on 2.6.24. I'll dig around some more to see if there's something that might be useful to you.


>2) Did you verify the VSTBY pin action (i.e. pin changes to high in
>state retention mode and the pmic changes the voltages to their
>programmed standby mode) ?
>3) As I already mentioned in my first post, the VSTBY signal is
>asserted, when I use a LTIB 2.6.21 build, but not in 2.6.38-rc1+
>> For our release that has LPM working:
>> 		/* Enable Well Bias and set VSTBY
>> 		  * VSTBY pin will be asserted during SR mode. This asks the
>> 		  * PM IC to set the core voltage to the standby voltage
>> 		  * Must clear the MXC_CCM_CCMR_SBYCS bit as well  */
>> 		mxc_ccm_modify_reg(MXC_CCM_CCMR,
>> Dinh
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