Triggering System State Transition from Linux

When Linux is configured as a System State Transition Privileged Guest, Linux can request a system state transition through its integrated drivers. On how to configure a guest as a privileged guest, refer to Enabling a Guest OS to request System State Transition. This release contains the tegra_hv_pm_ctl driver for initiating a System State Transition. The driver must be configured with an IVC to System Manager to function correctly. For information on how to configure the driver, refer to its DTB documentation:

drive-linux/kernel/source/oss_src/nvidia/Documentation/devicetree/bindings/tegra_hv/tegra_hv_pm_ctl.txt

When configured correctly, tegra_hv_pm_ctl creates two nodes as its sysfs. Writing an ASCII 1 will trigger the corresponding system state transition.

Privileged Guest must complete any communication with the Board Power State Management chipset before this request is made.

To trigger Timed Graceful System Shutdown

echo 1 > /sys/class/tegra_hv_pm_ctl/tegra_hv_pm_ctl/device/trigger_sys_shutdown

To trigger Timed Graceful System Shutdown

echo 1 > /sys/class/tegra_hv_pm_ctl/tegra_hv_pm_ctl/device/trigger_sys_shutdown

Receiving Partition State Transition Message

This release contains a userspace daemon to handle the Partition State Transition Message from SysMgr. As the userspace daemon does not have a direct access to DTB, which contains a specification of the IVC channel number to SysMgr, the tegra_hv_pm_ctl driver provides a character device node for the userspace daemon. This allows the daemon to monitor the following location, regardless of the underlying channel number: /dev/tegra_hv_pm_ctl.