AM3352: TPS65217C

Albert Wu

Part Number: AM3352

Dear TI,

Sometimes it will cause an auto reboot in our project after the shutdown command . I measure the signal ,When the auto reboot occurs, the TPS65217C PWR_EN signal will be Low -> High.

Since the TPS65217C PWR_EN pin is controlled by the AM3352 PMIC_POWER_EN pin. The kernel driver can't control it.
When executing shutdown now command, kernel driver call pm_power_off().

AM3352 will release the control of the pin at this time . TPS65217C set this pin to pull LOW. Once an auto reboot occurs, I want to know
why AM3352 sets this PMIC_POWER_EN pin to high .

over 4 years ago

0 Bin Liu over 4 years ago

TI__Guru**** 168211 points

Hi,

Is this the same query as the following thread?

https://e2e.ti.com/support/processors/f/processors-forum/992233/am3352-am3352-system-reboot-after-shutdown

0 Albert Wu over 4 years ago

Prodigy 235 points

Dear Bin,
This is the same problem. I think the root cause must be found.
Because AM3352 PMIC_POWER_EN pin is set to high behavior,
Only AM3352 can control AM3352 PMIC_POWER_EN pin to high levle.

When enter shutdown mode, why does AM3352
set AM3352 PMIC_POWER_EN pin to high levle.

0 Bin Liu over 4 years ago in reply to Albert Wu

TI__Guru**** 168211 points

Hi,

The pin PMIC_POWER_EN is controlled in AM335x by some hardware conditions, which are documented in the TRM. Have you reviewed the TRM about the PMIC_POWER_EN pin related information?

If you cannot find any clue there, I will review the TRM in the next couple days to summarize the control condition and reply it to the original thread https://e2e.ti.com/support/processors/f/processors-forum/992233/am3352-am3352-system-reboot-after-shutdown

0 Albert Wu over 4 years ago in reply to Bin Liu

Prodigy 235 points

Hi Bin,

I download AM335x Technical Reference Manual . I can't find why PMIC_POWER_EN pin is set to high level.

Why does the pin to be high in shutdown mode?

May you describe in detail ?

0 Bin Liu over 4 years ago in reply to Albert Wu

TI__Guru**** 168211 points

Hi Albert,

I don't look at this in TRM very often, so I have to review the TRM to refresh my memory, will do it in a couple days.

The TRM explains PMIC_POWER_EN is an output pin, which is controlled by a few conditions (input pins) to AM335x, so meanwhile please review the TRM to understand what these input events are, and probe your board to understand which of the inputs triggers PMIC_POWER_EN output during shutdown.

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AM3352: TPS65217C