[U-Boot] [PATCH 1/7] drivers: Add AXI uclass and ihs_axi driver

Mario Six mario.six at gdsys.cc
Wed Mar 28 12:40:15 UTC 2018


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 at gdsys.cc>
---
 drivers/Kconfig          |   2 +
 drivers/Makefile         |   1 +
 drivers/axi/Kconfig      |  24 ++++++
 drivers/axi/Makefile     |   9 +++
 drivers/axi/axi-uclass.c |  40 ++++++++++
 drivers/axi/ihs_axi.c    | 199 +++++++++++++++++++++++++++++++++++++++++++++++
 include/axi.h            |  75 ++++++++++++++++++
 include/dm/uclass-id.h   |   1 +
 8 files changed, 351 insertions(+)
 create mode 100644 drivers/axi/Kconfig
 create mode 100644 drivers/axi/Makefile
 create mode 100644 drivers/axi/axi-uclass.c
 create mode 100644 drivers/axi/ihs_axi.c
 create mode 100644 include/axi.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index c2e813f5ad..eeaaa7575c 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -8,6 +8,8 @@ source "drivers/adc/Kconfig"

 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 6846d181aa..f54a10f3ad 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -100,6 +100,7 @@ obj-y += input/
 obj-y += soc/
 obj-$(CONFIG_REMOTEPROC) += remoteproc/
 obj-y += thermal/
+obj-y += axi/

 obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
 endif
diff --git a/drivers/axi/Kconfig b/drivers/axi/Kconfig
new file mode 100644
index 0000000000..19e1b7fd2f
--- /dev/null
+++ b/drivers/axi/Kconfig
@@ -0,0 +1,24 @@
+menuconfig AXI
+	bool "AXI bus drivers"
+	help
+	  Support AXI (Advanced eXtensible Interface) busses, a on-chip
+	  interconnect specification for managing functional blocks in SoC
+	  designs, which is also often used in designs involving FPGAs (e.g.
+	  communication with IP cores in Xilinx FPGAs).
+
+	  These types of busses expose a virtual address space that can be
+	  accessed using different address widths (8, 16, and 32 are supported
+	  for now).
+
+	  Other similar bus architectures may be compatible as well.
+
+if AXI
+
+config IHS_AXI
+	bool "Enable IHS AXI driver"
+	depends on DM
+	help
+	  Support for IHS AXI bus on a gdsys IHS FPGA used to communicate with
+	  IP cores in the FPGA (e.g. video transmitter cores).
+
+endif
diff --git a/drivers/axi/Makefile b/drivers/axi/Makefile
new file mode 100644
index 0000000000..18d9380e9b
--- /dev/null
+++ b/drivers/axi/Makefile
@@ -0,0 +1,9 @@
+#
+# (C) Copyright 2017
+# Mario Six,  Guntermann & Drunck GmbH, mario.six at gdsys.cc
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_AXI) += axi-uclass.o
+obj-$(CONFIG_IHS_AXI) += ihs_axi.o
diff --git a/drivers/axi/axi-uclass.c b/drivers/axi/axi-uclass.c
new file mode 100644
index 0000000000..3a5ddf3a46
--- /dev/null
+++ b/drivers/axi/axi-uclass.c
@@ -0,0 +1,40 @@
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#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/drivers/axi/ihs_axi.c b/drivers/axi/ihs_axi.c
new file mode 100644
index 0000000000..71bb67421f
--- /dev/null
+++ b/drivers/axi/ihs_axi.c
@@ -0,0 +1,199 @@
+/*
+ * (C) Copyright 2016
+ * Dirk Eibach,  Guntermann & Drunck GmbH, dirk.eibach at gdsys.cc
+ *
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+#include <fpgamap.h>
+#include "../misc/gdsys_soc.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+enum {
+	REG_INTERRUPT_STATUS = 0x00,
+	REG_INTERRUPT_ENABLE_CONTROL = 0x02,
+	REG_ADDRESS_LSB = 0x04,
+	REG_ADDRESS_MSB = 0x06,
+	REG_WRITE_DATA_LSB = 0x08,
+	REG_WRITE_DATA_MSB = 0x0A,
+	REG_READ_DATA_LSB = 0x0C,
+	REG_READ_DATA_MSB = 0x0E,
+};
+
+struct ihs_axi_priv {
+	fdt_addr_t addr;
+};
+
+enum {
+	STATUS_EVENT_MASK = GENMASK(15, 12),
+
+	STATUS_READ_COMPLETE_EVENT = BIT(15),
+	STATUS_WRITE_COMPLETE_EVENT = BIT(14),
+	STATUS_TIMEOUT_EVENT = BIT(13),
+	STATUS_ERROR_EVENT = BIT(12),
+	STATUS_AXI_INT = BIT(11),
+	STATUS_READ_DATA_AVAILABLE = BIT(7),
+	STATUS_BUSY = BIT(6),
+	STATUS_INIT_DONE = BIT(5),
+};
+
+enum {
+	CONTROL_EVENT_ENABLE_MASK = GENMASK(15, 11),
+	CONTROL_CMD_MASK = GENMASK(3, 0),
+
+	CONTROL_READ_COMPLETE_EVENT_ENABLE = BIT(15),
+	CONTROL_WRITE_COMPLETE_EVENT_ENABLE = BIT(14),
+	CONTROL_TIMEOUT_EVENT_ENABLE = BIT(13),
+	CONTROL_ERROR_EVENT_ENABLE = BIT(12),
+	CONTROL_AXI_INT_ENABLE = BIT(11),
+
+	CONTROL_CMD_NOP = 0x0,
+	CONTROL_CMD_WRITE = 0x8,
+	CONTROL_CMD_WRITE_POST_INC = 0x9,
+	CONTROL_CMD_READ = 0xa,
+	CONTROL_CMD_READ_POST_INC = 0xb,
+
+};
+
+static int ihs_axi_transfer(struct udevice *bus, ulong address, u16 cmd,
+			    u16 complete_flag)
+{
+	struct ihs_axi_priv *priv = dev_get_priv(bus);
+	struct udevice *fpga;
+	u16 wait_mask = complete_flag | STATUS_TIMEOUT_EVENT |
+			STATUS_ERROR_EVENT;
+	u16 status;
+	u16 addr_low, addr_high;
+	uint k;
+
+	gdsys_soc_get_fpga(bus, &fpga);
+
+	cmd &= CONTROL_CMD_MASK;
+
+	addr_low = address & 0xffff;
+	fpgamap_write(fpga, priv->addr + REG_ADDRESS_LSB, &addr_low,
+		      FPGAMAP_SIZE_16);
+	addr_high = (address >> 16) & 0xffff;
+	fpgamap_write(fpga, priv->addr + REG_ADDRESS_MSB, &addr_high,
+		      FPGAMAP_SIZE_16);
+
+	fpgamap_write(fpga, priv->addr + REG_INTERRUPT_STATUS, &wait_mask,
+		      FPGAMAP_SIZE_16);
+	fpgamap_write(fpga, priv->addr + REG_INTERRUPT_ENABLE_CONTROL, &cmd,
+		      FPGAMAP_SIZE_16);
+
+	for (k = 10; k > 0; --k) {
+		fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &status,
+			     FPGAMAP_SIZE_16);
+		if (status & wait_mask)
+			break;
+		udelay(1);
+	}
+
+	if (!k)
+		fpgamap_read(fpga, priv->addr + REG_INTERRUPT_STATUS, &status,
+			     FPGAMAP_SIZE_16);
+
+	if (status & complete_flag)
+		return 0;
+
+	if (status & STATUS_ERROR_EVENT)
+		return -EIO;
+
+	return -ETIMEDOUT;
+}
+
+/*
+ * API
+ */
+
+int ihs_axi_read(struct udevice *dev, ulong address, void *data,
+		 enum axi_size_t size)
+{
+	struct ihs_axi_priv *priv = dev_get_priv(dev);
+	struct udevice *fpga;
+	int res = 0;
+	u16 data_lsb, data_msb;
+	u32 *p = data;
+
+	if (size != AXI_SIZE_32)
+		return -ENOSYS;
+
+	gdsys_soc_get_fpga(dev, &fpga);
+
+	res = ihs_axi_transfer(dev, address, CONTROL_CMD_READ,
+			       STATUS_READ_COMPLETE_EVENT);
+	if (res < 0)
+		return res;
+
+	fpgamap_read(fpga, priv->addr + REG_READ_DATA_LSB, &data_lsb,
+		     FPGAMAP_SIZE_16);
+	fpgamap_read(fpga, priv->addr + REG_READ_DATA_MSB, &data_msb,
+		     FPGAMAP_SIZE_16);
+
+	*p = (data_msb << 16) | data_lsb;
+
+	return res;
+}
+
+int ihs_axi_write(struct udevice *dev, ulong address, void *data,
+		  enum axi_size_t size)
+{
+	struct ihs_axi_priv *priv = dev_get_priv(dev);
+	struct udevice *fpga;
+	int res = 0;
+	u32 *p = data;
+	u16 data_low, data_high;
+
+	if (size != AXI_SIZE_32)
+		return -ENOSYS;
+
+	gdsys_soc_get_fpga(dev, &fpga);
+
+	data_low = *p & 0xffff;
+	fpgamap_write(fpga, priv->addr + REG_WRITE_DATA_LSB, &data_low,
+		      FPGAMAP_SIZE_16);
+	data_high = (*p >> 16) & 0xffff;
+	fpgamap_write(fpga, priv->addr + REG_WRITE_DATA_MSB, &data_high,
+		      FPGAMAP_SIZE_16);
+
+	res = ihs_axi_transfer(dev, address, CONTROL_CMD_WRITE,
+			       STATUS_WRITE_COMPLETE_EVENT);
+
+	return res;
+}
+
+static const struct udevice_id ihs_axi_ids[] = {
+	{ .compatible = "gdsys,ihs_axi" },
+	{ /* sentinel */ }
+};
+
+static const struct axi_ops ihs_axi_ops = {
+	.read = ihs_axi_read,
+	.write = ihs_axi_write,
+};
+
+int ihs_axi_probe(struct udevice *dev)
+{
+	struct ihs_axi_priv *priv = dev_get_priv(dev);
+
+	priv->addr = dev_read_u32_default(dev, "reg", -1);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(ihs_axi_bus) = {
+	.name           = "ihs_axi_bus",
+	.id             = UCLASS_AXI,
+	.of_match       = ihs_axi_ids,
+	.ops		= &ihs_axi_ops,
+	.priv_auto_alloc_size = sizeof(struct ihs_axi_priv),
+	.probe          = ihs_axi_probe,
+};
diff --git a/include/axi.h b/include/axi.h
new file mode 100644
index 0000000000..317e931a6c
--- /dev/null
+++ b/include/axi.h
@@ -0,0 +1,75 @@
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#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 07fabc3ce6..9857796e54 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -43,6 +43,7 @@ enum uclass_id {
 	UCLASS_I2C_GENERIC,	/* Generic I2C device */
 	UCLASS_I2C_MUX,		/* I2C multiplexer */
 	UCLASS_IDE,		/* IDE device */
+	UCLASS_AXI,		/* AXI busses */
 	UCLASS_IRQ,		/* Interrupt controller */
 	UCLASS_KEYBOARD,	/* Keyboard input device */
 	UCLASS_LED,		/* Light-emitting diode (LED) */
--
2.16.1



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