drivers: Add AXI uclass

Add a uclass for AXI (Advanced eXtensible Interface) busses, and a
driver for the gdsys IHS AXI bus on IHS FPGAs.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>

3 files changed, 60 insertions, 0 deletions

diff --git a/drivers/axi/Kconfig b/drivers/axi/Kconfig
new file mode 100644
index 0000000000..4e4153b428
--- /dev/null
+++ b/drivers/axi/Kconfig
@@ -0,0 +1,13 @@
+menuconfig AXI
+	bool "AXI bus drivers"
+	help
+	  Support AXI (Advanced eXtensible Interface) busses, a on-chip
+	  interconnect specification for managing functional blocks in SoC
+	  designs, which is also often used in designs involving FPGAs (e.g.
+	  communication with IP cores in Xilinx FPGAs).
+
+	  These types of busses expose a virtual address space that can be
+	  accessed using different address widths (8, 16, and 32 are supported
+	  for now).
+
+	  Other similar bus architectures may be compatible as well.
diff --git a/drivers/axi/Makefile b/drivers/axi/Makefile
new file mode 100644
index 0000000000..100a77788a
--- /dev/null
+++ b/drivers/axi/Makefile
@@ -0,0 +1,8 @@
+#
+# (C) Copyright 2017
+# Mario Six,  Guntermann & Drunck GmbH, mario.six@gdsys.cc
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_AXI) += axi-uclass.o
diff --git a/drivers/axi/axi-uclass.c b/drivers/axi/axi-uclass.c
new file mode 100644
index 0000000000..af8acd9f88
--- /dev/null
+++ b/drivers/axi/axi-uclass.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <axi.h>
+
+int axi_read(struct udevice *dev, ulong address, void *data,
+	     enum axi_size_t size)
+{
+	struct axi_ops *ops = axi_get_ops(dev);
+
+	if (!ops->read)
+		return -ENOSYS;
+
+	return ops->read(dev, address, data, size);
+}
+
+int axi_write(struct udevice *dev, ulong address, void *data,
+	      enum axi_size_t size)
+{
+	struct axi_ops *ops = axi_get_ops(dev);
+
+	if (!ops->write)
+		return -ENOSYS;
+
+	return ops->write(dev, address, data, size);
+}
+
+UCLASS_DRIVER(axi) = {
+	.id		= UCLASS_AXI,
+	.name		= "axi",
+	.post_bind	= dm_scan_fdt_dev,
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+};
+