AM3352: What is the preferred way to disable PMIC LDO in suspend to memory?

Matt Brown

Part Number: AM3352
Other Parts Discussed in Thread: TPS65217,

AM3352, with an external PMIC TPS65217.

Is it possible to disable an LDO in suspend to memory mode? What's the best approach to take for this? It seems like there's a combination of adjusting the TPS65217 to disable the LDO in this mode, along with lowering the PMIC_POWER_EN pin. I've been unsuccessful on configuring this, and am questioning if I have the right approach.

Thanks in advance!

over 5 years ago

0 JJD over 5 years ago

TI__Guru* 95381 points

Hi Matt, can you expand on what you mean by suspend to memory mode? If you look at table 8-13 in the TRM, this describes the low power modes which we support. DeepSleep0 is probably what you are talking about, where the DDR transitions to self-refresh mode to retain its contents. However, this mode requires all power supplies to remain on. The next step down is RTC mode, but this is essentially just keeping the RTC alive and shutting down everything else.

If you are referring to something else, let me know.

Regards,

James

0 Matt Brown over 5 years ago in reply to JJD

Prodigy 20 points

I should have translated to CPU state from a Linux state. The low power mode is DeepSleep0. Is there a preferred way to toggle PMIC_PWR_EN in this state using Linux?

0 JJD over 5 years ago in reply to Matt Brown

TI__Guru* 95381 points

I'm fairly sure our linux SDK takes care of all of the signaling necessary for deepsleep0. All of the low power linux support is described here:

http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components/Kernel/Kernel_Drivers/Power_Management.html

Regards,

James

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AM3352: What is the preferred way to disable PMIC LDO in suspend to memory?