Tegra power management firmware running on the co-processor (BPMP)
implements a simple pseudo file system akin to debugfs. The file
system can be used for debugging purposes to examine and change the
status of selected resources controlled by the firmware (such as
clocks, resets, voltages, powergates, ...).
Add support to "mirror" the firmware's file system to debugfs. At
boot, query firmware for a list of all possible files and create
corresponding debugfs entries. Read/write of individual files is
implemented by sending a Message ReQuest (MRQ) that passes the full
file path name and data to firmware via DRAM.
Signed-off-by: Timo Alho <talho@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The Boot and Power Management Processor (BPMP) is a co-processor found
on Tegra SoCs. It is designed to handle the early stages of the boot
process and offload power management tasks (such as clocks, resets,
powergates, ...) as well as system control services.
Compared to the ARM SCPI, the services provided by BPMP are message-
based rather than method-based. The BPMP firmware driver provides the
services to transmit data to and receive data from the BPMP. Users can
also register a Message ReQuest (MRQ), for which a service routine will
be run when a corresponding event is received from the firmware.
A set of messages, called the BPMP ABI, are specified for a number of
different services provided by the BPMP (such as clocks or resets).
Based on work by Sivaram Nair <sivaramn@nvidia.com> and Joseph Lo
<josephl@nvidia.com>.
Signed-off-by: Thierry Reding <treding@nvidia.com>
The Inter-VM communication (IVC) is a communication protocol which is
designed for interprocessor communication (IPC) or the communication
between the hypervisor and the virtual machine with a guest OS.
Message channels are used to communicate between processors. They are
backed by DRAM or SRAM, so care must be taken to maintain coherence of
data.
The IVC library maintains memory-based descriptors for the transmission
and reception channels as well as the data coherence of the counter and
payload. Clients, such as the driver for the BPMP firmware, can use the
library to exchange messages with remote processors.
Based on work by Peter Newman <pnewman@nvidia.com> and Joseph Lo
<josephl@nvidia.com>.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Timo Alho