stby led not glowing through low power suspend mode using imx93_lpm.c driver

[sbmd_1234]

Hi 

I am putting the system in low power suspend mode by "echo mem > /sys/power/state" but to drop the voltage I am using func. regulator_set_voltage_tol(soc_reg, 650000, 0), which is as :

if (event == PM_SUSPEND_PREPARE) {

system_run_mode.resume_mode = system_run_mode.current_mode;
/* make sure auto clock gating is disabled */
regmap_update_bits(regmap, AUTO_CG_CTRL, AUTO_CG_EN, 0);
sys_freq_scaling(no_od_mode ? ND_MODE : OD_MODE);
/* save the ssi idle strap */
regmap_read(regmap, AUTO_CG_CTRL, &system_run_mode.ssi_strap);
regulator_set_voltage_tol(soc_reg, 650000, 0);
}

By this change, VDD_SOC voltage dropped to 0.65 but stby LED in Baseboard not glowing why? As stby pin of imx93 is connected to LED as I have checked in schematics.

Please tell me a reason what is happening here.

Thanks.

[sbmd_1234]

Hi @Chavira 

Thanks for your reply!!

I am using imx93 EVK and my BSP is 6.1.y+gitAUTOINC+770c5fe2c1.

Actually, without any modifications, it is working fine but I want to check in this way by setting the voltage by regulator_set_voltage_tol(soc_reg, 650000, 0); as in above I have asked for my understanding purpose it should work also in this way right?

According to schematics, pmic_stby_req output is coming from imx93 soc as input to stby LED. It should glow if system is going to LPM.

So through this D1415 stby LED not going high? But VDD_SOC works set to 0.65V why this is happening?

Thanks. 

[Chavira]

Hi @sbmd_1234!

You can check the function "sys_freq_scaling"  the driver set the voltage depending on the mode to be set.

The driver is working as we provide and any customization that you made it to our driver is not supported by NXP.

We can help to cuztomize our drivers according  to your necessities only under pro support.

https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/drivers/soc/imx/imx93_lpm.c#L134

Best Regards!

Chavira

[sbmd_1234]

Hi @Chavira 

Can you please confirm which particular code or function is responsible for putting the system in low-power mode?

As I am running the echo mem > /sys/power/state command that is taking the system to low-power mode I want to know how it working.

[sbmd_1234]

Hi 

I have a doubt when after the system goes to suspend mode is there any way in NXP PMIC driver to detect system fully went to suspend mode?

[Chavira]

Hi @sbmd_1234!

Thank you for contacting NXP Support!

What board and BSP are you using?

I tried with iMX93-EVK without your modification and works fine, the VDD_SOC dropped to 0.647 and the LED connected turn on and off respectly.

I recommend to use the driver as we provide and try it.

You can download our schematic by following the link:

https://www.nxp.com/webapp/Download?colCode=MCIMX93-BB

https://www.nxp.com/webapp/Download?colCode=MCIMX93-SOM

How are you connecting the LED to the processor?

Can you share the schematic?

Best Regards!

Chavira

[sbmd_1234]

Hi @Chavira 

Any suggestion on this waiting for your reply!

[Chavira]

Hi @sbmd_1234!

for regulator_set_voltage_tol function, it just modify the voltage, but the cmd "echo mem > /sys/power/state" will put the system enter lpm including voltage and clk, and not only the VDD_SOC, i mean it also will make other peripherals enter lpm.

you can get it like this, regulator_set_voltage_tol is VDD_SOC level, and echo mem > /sys/power/state is system level.