arm: rpi: Add a file to handle messages
The bcm283x chips provide a way for the ARM core to communicate with the
graphics processor, which is in charge of many things. This is handled by
way of a message prototcol.
At present the code for sending message (and receiving a reply) is spread
around U-Boot, primarily in the board file. This means that sending a
message from a driver requires duplicating the code.
Create a new message implementation with a function to support powering on
a subsystem as a starting point.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-bcm283x/include/mach/msg.h b/arch/arm/mach-bcm283x/include/mach/msg.h
new file mode 100644
index 0000000..3bcb5db
--- /dev/null
+++ b/arch/arm/mach-bcm283x/include/mach/msg.h
@@ -0,0 +1,18 @@
+/*
+ * (C) Copyright 2012,2015 Stephen Warren
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef _BCM2835_MSG_H
+#define _BCM2835_MSG_H
+
+/**
+ * bcm2835_power_on_module() - power on an SoC module
+ *
+ * @module: ID of module to power on (BCM2835_MBOX_POWER_DEVID_...)
+ * @return 0 if OK, -EIO on error
+ */
+int bcm2835_power_on_module(u32 module);
+
+#endif