firmware: scmi: mailbox/smt agent device
This change implements a mailbox transport using SMT format for SCMI
exchanges. This implementation follows the Linux kernel and
SCP-firmware [1] as references implementation for SCMI message
processing using SMT format for communication channel meta-data.
Use of mailboxes in SCMI FDT bindings are defined in the Linux kernel
DT bindings since v4.17.
Links: [1] https://github.com/ARM-software/SCP-firmware
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/firmware/scmi/Kconfig b/drivers/firmware/scmi/Kconfig
index 57e2ebb..c501bf4 100644
--- a/drivers/firmware/scmi/Kconfig
+++ b/drivers/firmware/scmi/Kconfig
@@ -2,7 +2,7 @@
bool "Enable SCMI support"
select FIRMWARE
select OF_TRANSLATE
- depends on SANDBOX
+ depends on SANDBOX || DM_MAILBOX
help
System Control and Management Interface (SCMI) is a communication
protocol that defines standard interfaces for power, performance
@@ -14,4 +14,6 @@
or a companion host in the CPU system.
Communications between agent (client) and the SCMI server are
- based on message exchange.
+ based on message exchange. Messages can be exchange over tranport
+ channels as a mailbox device with some piece of identified shared
+ memory.