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>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index c72abf8..56536c4 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -8,6 +8,8 @@
source "drivers/ata/Kconfig"
+source "drivers/axi/Kconfig"
+
source "drivers/block/Kconfig"
source "drivers/bootcount/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index d532085..d296354 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -103,6 +103,7 @@
obj-y += soc/
obj-$(CONFIG_REMOTEPROC) += remoteproc/
obj-y += thermal/
+obj-y += axi/
obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
endif
diff --git a/drivers/axi/Kconfig b/drivers/axi/Kconfig
new file mode 100644
index 0000000..4e4153b
--- /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 0000000..100a777
--- /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 0000000..af8acd9
--- /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,
+};
+
diff --git a/include/axi.h b/include/axi.h
new file mode 100644
index 0000000..2ff81c1
--- /dev/null
+++ b/include/axi.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#ifndef _AXI_H_
+#define _AXI_H_
+
+enum axi_size_t {
+ AXI_SIZE_8,
+ AXI_SIZE_16,
+ AXI_SIZE_32,
+};
+
+/**
+ * struct axi_ops - driver operations for AXI uclass
+ *
+ * Drivers should support these operations unless otherwise noted. These
+ * operations are intended to be used by uclass code, not directly from
+ * other code.
+ */
+struct axi_ops {
+ /**
+ * read() - Read a single value from a specified address on a AXI bus
+ *
+ * @dev: AXI bus to read from.
+ * @address: The address to read from.
+ * @data: Pointer to a variable that takes the data value read
+ * from the address on the AXI bus.
+ * @size: The size of the data to be read.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*read)(struct udevice *dev, ulong address, void *data,
+ enum axi_size_t size);
+
+ /**
+ * write() - Write a single value to a specified address on a AXI bus
+ *
+ * @dev: AXI bus to write to.
+ * @address: The address to write to.
+ * @data: Pointer to the data value to be written to the address
+ * on the AXI bus.
+ * @size: The size of the data to write.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*write)(struct udevice *dev, ulong address, void *data,
+ enum axi_size_t size);
+};
+
+#define axi_get_ops(dev) ((struct axi_ops *)(dev)->driver->ops)
+
+/**
+ * axi_read() - Read a single value from a specified address on a AXI bus
+ *
+ * @dev: AXI bus to read from.
+ * @address: The address to read from.
+ * @data: Pointer to a variable that takes the data value read from the
+ * address on the AXI bus.
+ * @size: The size of the data to write.
+ * @return 0 if OK, -ve on error.
+ */
+int axi_read(struct udevice *dev, ulong address, void *data,
+ enum axi_size_t size);
+
+/**
+ * axi_write() - Write a single value to a specified address on a AXI bus
+ *
+ * @dev: AXI bus to write to.
+ * @address: The address to write to.
+ * @data: Pointer to the data value to be written to the address on the
+ * AXI bus.
+ * @size: The size of the data to write.
+ * @return 0 if OK, -ve on error.
+ */
+int axi_write(struct udevice *dev, ulong address, void *data,
+ enum axi_size_t size);
+#endif
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index a39643e..618f43a 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -43,6 +43,7 @@
UCLASS_I2C_GENERIC, /* Generic I2C device */
UCLASS_I2C_MUX, /* I2C multiplexer */
UCLASS_IDE, /* IDE device */
+ UCLASS_AXI, /* AXI bus */
UCLASS_IRQ, /* Interrupt controller */
UCLASS_KEYBOARD, /* Keyboard input device */
UCLASS_LED, /* Light-emitting diode (LED) */