[nrf fromtree] drivers: firmware: TISCI driver support

Added TISCI driver for supported devices using the binding ti,k2g-sci.
This is used to communicate via the secury proxy channel for clock,
resource and power domain management.
Refer: https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/general/TISCI_header.html

Signed-off-by: Dave Joseph <[email protected]>
(cherry picked from commit 95c20c3)

Author: Kronosblaster

drivers/firmware/CMakeLists.txt

@@ -3,4 +3,5 @@
 # zephyr-keep-sorted-start
 add_subdirectory_ifdef(CONFIG_ARM_SCMI scmi)
 add_subdirectory_ifdef(CONFIG_NRF_IRONSIDE nrf_ironside)
+add_subdirectory_ifdef(CONFIG_TISCI tisci)
 # zephyr-keep-sorted-stop

drivers/firmware/Kconfig

@@ -13,6 +13,7 @@ config ARM_SCMI
 # zephyr-keep-sorted-start
 source "drivers/firmware/nrf_ironside/Kconfig"
 source "drivers/firmware/scmi/Kconfig"
+source "drivers/firmware/tisci/Kconfig"
 # zephyr-keep-sorted-stop
 
 endmenu

drivers/firmware/tisci/CMakeLists.txt

@@ -0,0 +1,6 @@
+# Copyright (c) 2025, Texas Instruments
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_TISCI tisci.c)

drivers/firmware/tisci/Kconfig

@@ -0,0 +1,22 @@
+# Copyright (c) 2025, Texas Instruments
+# SPDX-License-Identifier: Apache-2.0
+
+config TISCI
+	bool "TISCI Firmware driver"
+	default y
+	depends on DT_HAS_TI_K2G_SCI_ENABLED
+	select MBOX
+	help
+	  TISCI firmware driver is a frontend interface
+	  to TI System Controller interface firmware through
+	  secureproxy mailbox.
+
+if TISCI
+
+config TISCI_INIT_PRIORITY
+	int "TISCI init priority"
+	default KERNEL_INIT_PRIORITY_OBJECTS
+	help
+	  Init priority for the TISCI driver.
+
+endif