Commits
Suman Anna committed ad0833e3cf8
remoteproc/k3-r5: add support for IPC-only mode for all R5Fs on J721E SoCs
Add support to the K3 R5F remoteproc driver to configure all the R5F cores
on J721E SoCs to be either in IPC-only mode or the traditional remoteproc
mode. The IPC-only mode expects that the remote processors are already
booted by the bootloader, and only perform the minimum steps required to
initialize and deinitialize the virtio IPC transports. The remoteproc mode
allows the kernel remoteproc driver to do the regular load and boot and
other device management operations for a R5F core.
The IPC-only mode for a R5F core is detected and configured at driver
probe time by querying the System Firmware for the R5F power and reset
state and/or status and making sure that the R5F core is indeed started
by the bootloaders, otherwise the device is configured for remoteproc
mode.
Support for IPC-only mode is achieved through various flags in both
remoteproc core and the K3 R5F remoteproc driver. The support in
remoteproc core for this is added in commit 20afed1b45bf ("remoteproc:
add infrastructure support to allow pre-loaded remoteprocs"). The support
requires that the firmware still be requested to process the resource
table for retrieving the virtio device and trace resource entries.
NOTE:
- The driver cannot configure a R5F core for remoteproc mode by any
means without rebooting the kernel if that R5F core has been started
by a bootloader.
- The IPC-only mode support is currently limited to only J721E SoCs.
Functionality on AM65x SoCs will be added in the future.
- The resource table address retrieval logic can actually be done by
providing the data through device tree (thereby bypassing the need to
request the firmware), with the bootloader adding and/or updating the
necessary DT properties. Another option is to use a design-by-contract
approach of having the resource table located at a specific offset
within one of the memory regions. This will be optimized for in
the future.
Signed-off-by: Suman Anna <s-anna@ti.com>