Linux/PROCESSOR-SDK-AM335X: Power management

Hi Biser,
Thanks for your response.
i am using am335x sdk7 and the document referred by you which is more advanced am43xx. In our tree "Generic DT based cpufreq driver using clk notifiers" is not there in our kernel tree. and please share the am335x related dts for power management techniques definition in sdk7 related.
regards

Hi,

I am using battery operated using am335x. and i have touch, lcd, key provision i have. 

how can i control the power management scenarios in our background application.

how to invoke my key for wakeup the processor. where should i call my key int in kernel.

regards,

Lofna,

You can wakeup from standby from any of the GPIO lines by pressing any button/key connected to a GPIO line. For wakeup from deepsleep0/mem state, GPIO0 should be used.

For how to use GPIO to wake up AM335x device, check the below links:

processors.wiki.ti.com/.../Processor_SDK_Linux_GPIO_Driver_Overview

Regards,
Pavel

Hi,

I am using keypad in our design it have interrupt pin and attached the below pic for your understanding.

I don't have gpio's to trigger in our side. Only touch or keypad provision to wake up.

regards

Lofna,

From what I understand, your keypad U22 chip is attached to AM335x I2C0 interface.

You can use this keypad to wakeup the AM335x device through I2C0, this is possible. Check AM335x TRM (ch 8 PRCM) for more info.

Regards,
Pavel

Hi,

I did't get this "Check AM335x TRM (ch 8 PRCM) for more info."

Can you please help me how to wakeup.

rgrds

Lofna,

In your first post you state that you are "Using am335x evm". Is that still valid, or you are asking now for am335x custom board (not evm)?

lofna kumari said:

I did't get this "Check AM335x TRM (ch 8 PRCM) for more info."

You can get the AM335x TRM from the below link:

Check sections:

8.1.4.3 Power Modes

8.1.4.3.4 DeepSleep0

8.1.4.5 Wakeup Sources/Events

lofna kumari said:

Can you please help me how to wakeup.

You can use AM335x I2C0 to wakeup the AM335x device. But this feature is not enabled by default in linux kernel, you should develop/enable it. You can get example code from AM335x StarterWare package, where I2C0 is used for wake-up:

In TI linux kernel, by default we have the below wake-up sources:

1. UART/console

2. GPIO0 - One can wakeup from standby from any of the GPIO lines by pressing any button/key connected to a GPIO line

3. Touchscreen - Wakeup from standby mode is possible via internal TSC-ADC module. Pressing the touchscreen will cause a wake-up.

4. RTC

5. Timer

For adding I2C0, you can examine the StarterWare package and TRM chapter 21 I2C

Regards,
Pavel