Tool/software:
Dear TI Support Team,
I am working with the AM437x Linux-RT SDK (version 09.03.05.02) and would like to configure DMTimer3 as a wakeup source to resume the system from standby (`echo standby > /sys/power/state`). I am currently using multiple DMTimers, including DMTimer3, 6, and 7, but intend to use DMTimer3 specifically for wakeup from shallow suspend.
Could you please advise on the following items?
1. **Device Tree Definition for DMTimer3 Wakeup Functionality**
- What is the recommended way to configure DMTimer3 as a wakeup source in the device tree?
- Could you explicitly specify the correct `interrupts = <...>` value for DMTimer3?
- Also, please point me to the official documentation or TRM section that lists the mapping between DMTimer instances and their associated interrupt numbers (GIC SPI IRQs).
2. **User-Space Application Usage**
- When accessing DMTimer3 from a user-space application (e.g., via `/dev/mem`), are there any specific caveats or usage restrictions to consider to ensure wakeup functionality works reliably?
- Are there any known issues when using register-level access or specific settings (TCLR, TIER) that could interfere with wakeup?
3. **Kernel Build-Time Requirements**
- What kernel configuration options must be enabled to allow the DMTimer wakeup functionality to work?
- Are specific settings required (e.g. CONFIG_PM_SLEEP, TI PM drivers, or wakeup-related modules)?
My goal is to confirm that DMTimer3 generates an interrupt during standby and successfully wakes the system, with corresponding `PM: Wakeup source 48042000.timer` messages in the kernel log.
Any reference code, documentation links, or validation steps would be very helpful.
Thank you for your support!
Best regards,
Hiro,
