Merge tag 'omap-for-v4.5/wakeup-m3' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tmlind/linux-omap into next/drivers

TI wakeup M3 IPC device driver for v4.5 merge window. This driver will
eventually allow am33xx and am437x to support PM with their Cortex-M3
power management processor.

This driver has been waiting to get merged for quite a while but has
had dependencies to the remoteproc that are now out of the way.

* tag 'omap-for-v4.5/wakeup-m3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  soc: ti: Add wkup_m3_ipc driver
  Documentation: dt: add bindings for TI Wakeup M3 IPC device

Signed-off-by: Olof Johansson <olof@lixom.net>

Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt

@@ -0,0 +1,57 @@
+Wakeup M3 IPC Driver
+=====================
+
+The TI AM33xx and AM43xx family of devices use a small Cortex M3 co-processor
+(commonly referred to as Wakeup M3 or CM3) to help with various low power tasks
+that cannot be controlled from the MPU, like suspend/resume and certain deep
+C-states for CPU Idle. Once the wkup_m3_ipc driver uses the wkup_m3_rproc driver
+to boot the wkup_m3, it handles communication with the CM3 using IPC registers
+present in the SoC's control module and a mailbox. The wkup_m3_ipc exposes an
+API to allow the SoC PM code to execute specific PM tasks.
+
+Wkup M3 Device Node:
+====================
+A wkup_m3_ipc device node is used to represent the IPC registers within an
+SoC.
+
+Required properties:
+--------------------
+- compatible:		Should be,
+				"ti,am3352-wkup-m3-ipc" for AM33xx SoCs
+				"ti,am4372-wkup-m3-ipc" for AM43xx SoCs
+- reg:			Contains the IPC register address space to communicate
+			with the Wakeup M3 processor
+- interrupts:		Contains the interrupt information for the wkup_m3
+			interrupt that signals the MPU.
+- ti,rproc:		phandle to the wkup_m3 rproc node so the IPC driver
+			can boot it.
+- mboxes:		phandles used by IPC framework to get correct mbox
+			channel for communication. Must point to appropriate
+			mbox_wkupm3 child node.
+
+Example:
+--------
+/* AM33xx */
+	l4_wkup: l4_wkup@44c00000 {
+		...
+
+		scm: scm@210000 {
+			compatible = "ti,am3-scm", "simple-bus";
+			reg = <0x210000 0x2000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 0x210000 0x2000>;
+
+			...
+
+			wkup_m3_ipc: wkup_m3_ipc@1324 {
+				compatible = "ti,am3352-wkup-m3-ipc";
+				reg = <0x1324 0x24>;
+				interrupts = <78>;
+				ti,rproc = <&wkup_m3>;
+				mboxes = <&mailbox &mbox_wkupm3>;
+			};
+
+			...
+		};
+	};

drivers/soc/ti/Kconfig

@@ -28,4 +28,14 @@ config KEYSTONE_NAVIGATOR_DMA
 
 	  If unsure, say N.
 
+config WKUP_M3_IPC
+	tristate "TI AMx3 Wkup-M3 IPC Driver"
+	depends on WKUP_M3_RPROC
+	depends on OMAP2PLUS_MBOX
+	help
+	  TI AM33XX and AM43XX have a Cortex M3, the Wakeup M3, to handle
+	  low power transitions. This IPC driver provides the necessary API
+	  to communicate and use the Wakeup M3 for PM features like suspend
+	  resume and boots it using wkup_m3_rproc driver.
+
 endif # SOC_TI

drivers/soc/ti/Makefile

@@ -4,3 +4,4 @@
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_QMSS)	+= knav_qmss.o
 knav_qmss-y := knav_qmss_queue.o knav_qmss_acc.o
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA)	+= knav_dma.o
+obj-$(CONFIG_WKUP_M3_IPC)		+= wkup_m3_ipc.o