[U-Boot] [PATCH v2 2/7] axi: Add ihs_axi driver

[Mario Six]

Add a driver for the gdsys IHS AXI bus used on IHS FPGAs.

Signed-off-by: Mario Six <mario.six at gdsys.cc>

---

v1 -> v2:
New in v2

---
 drivers/axi/Kconfig   |  12 ++++
 drivers/axi/Makefile  |   1 +
 drivers/axi/ihs_axi.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 192 insertions(+)
 create mode 100644 drivers/axi/ihs_axi.c

diff --git a/drivers/axi/Kconfig b/drivers/axi/Kconfig
index 4e4153b4283..ae80c98af8a 100644
--- a/drivers/axi/Kconfig
+++ b/drivers/axi/Kconfig
@@ -11,3 +11,15 @@ menuconfig AXI
 	  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 gdsys Integrated Hardware Systems Advanced eXtensible
+	  Interface (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
index 100a77788a2..18d9380e9ba 100644
--- a/drivers/axi/Makefile
+++ b/drivers/axi/Makefile
@@ -6,3 +6,4 @@
 #

 obj-$(CONFIG_AXI) += axi-uclass.o
+obj-$(CONFIG_IHS_AXI) += ihs_axi.o
diff --git a/drivers/axi/ihs_axi.c b/drivers/axi/ihs_axi.c
new file mode 100644
index 00000000000..21227638f78
--- /dev/null
+++ b/drivers/axi/ihs_axi.c
@@ -0,0 +1,179 @@
+/*
+ * (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 <regmap.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct ihs_axi_regs {
+	u16 interrupt_status;
+	u16 interrupt_enable_control;
+	u16 address_lsb;
+	u16 address_msb;
+	u16 write_data_lsb;
+	u16 write_data_msb;
+	u16 read_data_lsb;
+	u16 read_data_msb;
+};
+
+#define ihs_axi_set(map, member, val) \
+	regmap_set(map, struct ihs_axi_regs, member, val)
+
+#define ihs_axi_get(map, member, valp) \
+	regmap_get(map, struct ihs_axi_regs, member, valp)
+
+struct ihs_axi_priv {
+	struct regmap *map;
+};
+
+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);
+	u16 wait_mask = complete_flag | STATUS_TIMEOUT_EVENT |
+			STATUS_ERROR_EVENT;
+	u16 status;
+	uint k;
+
+	cmd &= CONTROL_CMD_MASK;
+
+	ihs_axi_set(priv->map, address_lsb, address & 0xffff);
+	ihs_axi_set(priv->map, address_msb, (address >> 16) & 0xffff);
+
+	ihs_axi_set(priv->map, interrupt_status, wait_mask);
+	ihs_axi_set(priv->map, interrupt_enable_control, cmd);
+
+	for (k = 10; k > 0; --k) {
+		ihs_axi_get(priv->map, interrupt_status, &status);
+		if (status & wait_mask)
+			break;
+		udelay(1);
+	}
+
+	if (!k)
+		ihs_axi_get(priv->map, interrupt_status, &status);
+
+	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);
+	int res = 0;
+	u16 data_lsb, data_msb;
+	u32 *p = data;
+
+	if (size != AXI_SIZE_32)
+		return -ENOSYS;
+
+	res = ihs_axi_transfer(dev, address, CONTROL_CMD_READ,
+			       STATUS_READ_COMPLETE_EVENT);
+	if (res < 0)
+		return res;
+
+	ihs_axi_get(priv->map, read_data_lsb, &data_lsb);
+	ihs_axi_get(priv->map, read_data_msb, &data_msb);
+
+	*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);
+	int res = 0;
+	u32 *p = data;
+
+	if (size != AXI_SIZE_32)
+		return -ENOSYS;
+
+	ihs_axi_set(priv->map, write_data_lsb, *p & 0xffff);
+	ihs_axi_set(priv->map, write_data_msb, (*p >> 16) & 0xffff);
+
+	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);
+
+	regmap_init_mem(dev_ofnode(dev), &priv->map);
+
+	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,
+};
--
2.11.0