TS-4300 Low Power Mode

Low Drive Overlay

In order to enable Low Drive (LD) mode, the imx93-ts4300-ld.dtbo device tree overlay must be loaded at boot. This is controlled using the u-boot extra_fdt_overlays environment variable. To set that from linux:

fw_setenv extra_fdt_overlays imx93-ts4300-ld.dtbo

The device tree overlay will be picked up on the next boot.

Enable Low Drive Mode

The CPU Low Power Mode is controlled by the imx93-lpm driver through /sys/devices/platform/imx93-lpm/mode

The lpm mode supports 4 modes, 0-3, but only 0 (overdrive) and 3 (low drive) modes are currently supported. To see what mode you are in:

root@tsimx9:~# cat /sys/devices/platform/imx93-lpm/mode 
System is in OD mode with DDR 3200 MTS!

To switch to LD/SWFFC mode:

root@tsimx9:~# echo 3 > /sys/devices/platform/imx93-lpm/mode
[  410.931987] System switching to LD/SWFFC mode...
root@tsimx9:~# cat /sys/devices/platform/imx93-lpm/mode
System is in LD mode with DDR 625 MTS!

CPU and RAM speeds are decreased in Low Drive mode to save power without going to sleep. See Power Consumption for expected power savings and Sleep Mode for details on light and deep sleep modes.