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>

3 files changed, 58 insertions, 1 deletions

diff --git a/arch/arm/mach-bcm283x/Makefile b/arch/arm/mach-bcm283x/Makefile
index 5cb1b2f..b5f606e 100644
--- a/arch/arm/mach-bcm283x/Makefile
+++ b/arch/arm/mach-bcm283x/Makefile
@@ -5,4 +5,4 @@
 #
 
 obj-$(CONFIG_BCM2835) += lowlevel_init.o
-obj-y	+= init.o reset.o mbox.o phys2bus.o
+obj-y	+= init.o reset.o mbox.o msg.o phys2bus.o
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
diff --git a/arch/arm/mach-bcm283x/msg.c b/arch/arm/mach-bcm283x/msg.c
new file mode 100644
index 0000000..08b1bea
--- /dev/null
+++ b/arch/arm/mach-bcm283x/msg.c
@@ -0,0 +1,39 @@
+/*
+ * (C) Copyright 2012 Stephen Warren
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <memalign.h>
+#include <asm/arch/mbox.h>
+
+struct msg_set_power_state {
+	struct bcm2835_mbox_hdr hdr;
+	struct bcm2835_mbox_tag_set_power_state set_power_state;
+	u32 end_tag;
+};
+
+int bcm2835_power_on_module(u32 module)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(struct msg_set_power_state, msg_pwr, 1);
+	int ret;
+
+	BCM2835_MBOX_INIT_HDR(msg_pwr);
+	BCM2835_MBOX_INIT_TAG(&msg_pwr->set_power_state,
+			      SET_POWER_STATE);
+	msg_pwr->set_power_state.body.req.device_id = module;
+	msg_pwr->set_power_state.body.req.state =
+		BCM2835_MBOX_SET_POWER_STATE_REQ_ON |
+		BCM2835_MBOX_SET_POWER_STATE_REQ_WAIT;
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN,
+				     &msg_pwr->hdr);
+	if (ret) {
+		printf("bcm2835: Could not set module %u power state\n",
+		       module);
+		return -EIO;
+	}
+
+	return 0;
+}