drivers: mbox: TI Secure Proxy mbox drivers

Added secure proxy mailbox driver for supported devices using
the binding ti,secure-proxy. This is used to communicate with
a device manager running on a separate core via a secure proxy
mailbox for TI K3 devices. Required for enabling TISCI layer
communication.
Refer: https://software-dl.ti.com/tisci/esd/latest/1_intro/TISCI.html

Tested on MAIN_CORTEX_R5_0 on AM243x EVM.
Refer:https://www.ti.com/lit/pdf/spruim2

Co-developed-by: Vaishnav Achath <[email protected]>
Signed-off-by: Dave Joseph <[email protected]>

Author: Kronosblaster

drivers/mbox/CMakeLists.txt

@@ -22,3 +22,4 @@ zephyr_library_sources_ifdef(CONFIG_MBOX_IVSHMEM mbox_ivshmem.c)
 zephyr_library_sources_ifdef(CONFIG_MBOX_TI_OMAP_MAILBOX   mbox_ti_omap.c)
 zephyr_library_sources_ifdef(CONFIG_MBOX_RENESAS_RZ_MHU mbox_renesas_rz_mhu.c)
 zephyr_library_sources_ifdef(CONFIG_MBOX_MHUV3   mbox_mhuv3.c)
+zephyr_library_sources_ifdef(CONFIG_MBOX_TI_SECURE_PROXY   mbox_ti_secproxy.c)

drivers/mbox/Kconfig

@@ -26,7 +26,7 @@ source "drivers/mbox/Kconfig.ivshmem"
 source "drivers/mbox/Kconfig.ti_omap"
 source "drivers/mbox/Kconfig.renesas_rz"
 source "drivers/mbox/Kconfig.mhuv3"
-
+source "drivers/mbox/Kconfig.ti_secproxy"
 
 config MBOX_INIT_PRIORITY
 	int "MBOX init priority"

drivers/mbox/Kconfig.ti_secproxy

@@ -0,0 +1,15 @@
+# Copyright 2025 Texas Instruments Incorporated.
+# SPDX-License-Identifier: Apache-2.0
+
+config MBOX_TI_SECURE_PROXY
+	bool "TI Secureproxy Mailbox driver"
+	default y
+	depends on DT_HAS_TI_SECURE_PROXY_ENABLED
+	help
+	  Driver for TI Secure Proxy Mailbox.
+
+config MBOX_TI_SECURE_PROXY_PRIORITY
+	int "MBOX_TI_SECURE_PROXY_PRIORITY"
+	default KERNEL_INIT_PRIORITY_OBJECTS
+	help
+	  Mbox secproxy initialization priority.