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-rw-r--r--drivers/fpga/Kconfig7
-rw-r--r--drivers/fpga/Makefile3
-rw-r--r--drivers/fpga/fpga-bridge.c395
-rw-r--r--include/linux/fpga/fpga-bridge.h60
4 files changed, 465 insertions, 0 deletions
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index cd84934774cc..9b20f45c85bf 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -26,6 +26,13 @@ config FPGA_MGR_ZYNQ_FPGA
help
FPGA manager driver support for Xilinx Zynq FPGAs.
+config FPGA_BRIDGE
+ tristate "FPGA Bridge Framework"
+ depends on OF
+ help
+ Say Y here if you want to support bridges connected between host
+ processors and FPGAs or between FPGAs.
+
endif # FPGA
endmenu
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 8d83fc6b1613..4baef0022d4c 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -8,3 +8,6 @@ obj-$(CONFIG_FPGA) += fpga-mgr.o
# FPGA Manager Drivers
obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o
obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o
+
+# FPGA Bridge Drivers
+obj-$(CONFIG_FPGA_BRIDGE) += fpga-bridge.o
diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
new file mode 100644
index 000000000000..33ee83e6373c
--- /dev/null
+++ b/drivers/fpga/fpga-bridge.c
@@ -0,0 +1,395 @@
+/*
+ * FPGA Bridge Framework Driver
+ *
+ * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+static DEFINE_IDA(fpga_bridge_ida);
+static struct class *fpga_bridge_class;
+
+/* Lock for adding/removing bridges to linked lists*/
+spinlock_t bridge_list_lock;
+
+static int fpga_bridge_of_node_match(struct device *dev, const void *data)
+{
+ return dev->of_node == data;
+}
+
+/**
+ * fpga_bridge_enable - Enable transactions on the bridge
+ *
+ * @bridge: FPGA bridge
+ *
+ * Return: 0 for success, error code otherwise.
+ */
+int fpga_bridge_enable(struct fpga_bridge *bridge)
+{
+ dev_dbg(&bridge->dev, "enable\n");
+
+ if (bridge->br_ops && bridge->br_ops->enable_set)
+ return bridge->br_ops->enable_set(bridge, 1);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_bridge_enable);
+
+/**
+ * fpga_bridge_disable - Disable transactions on the bridge
+ *
+ * @bridge: FPGA bridge
+ *
+ * Return: 0 for success, error code otherwise.
+ */
+int fpga_bridge_disable(struct fpga_bridge *bridge)
+{
+ dev_dbg(&bridge->dev, "disable\n");
+
+ if (bridge->br_ops && bridge->br_ops->enable_set)
+ return bridge->br_ops->enable_set(bridge, 0);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_bridge_disable);
+
+/**
+ * of_fpga_bridge_get - get an exclusive reference to a fpga bridge
+ *
+ * @np: node pointer of a FPGA bridge
+ * @info: fpga image specific information
+ *
+ * Return fpga_bridge struct if successful.
+ * Return -EBUSY if someone already has a reference to the bridge.
+ * Return -ENODEV if @np is not a FPGA Bridge.
+ */
+struct fpga_bridge *of_fpga_bridge_get(struct device_node *np,
+ struct fpga_image_info *info)
+
+{
+ struct device *dev;
+ struct fpga_bridge *bridge;
+ int ret = -ENODEV;
+
+ dev = class_find_device(fpga_bridge_class, NULL, np,
+ fpga_bridge_of_node_match);
+ if (!dev)
+ goto err_dev;
+
+ bridge = to_fpga_bridge(dev);
+ if (!bridge)
+ goto err_dev;
+
+ bridge->info = info;
+
+ if (!mutex_trylock(&bridge->mutex)) {
+ ret = -EBUSY;
+ goto err_dev;
+ }
+
+ if (!try_module_get(dev->parent->driver->owner))
+ goto err_ll_mod;
+
+ dev_dbg(&bridge->dev, "get\n");
+
+ return bridge;
+
+err_ll_mod:
+ mutex_unlock(&bridge->mutex);
+err_dev:
+ put_device(dev);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(of_fpga_bridge_get);
+
+/**
+ * fpga_bridge_put - release a reference to a bridge
+ *
+ * @bridge: FPGA bridge
+ */
+void fpga_bridge_put(struct fpga_bridge *bridge)
+{
+ dev_dbg(&bridge->dev, "put\n");
+
+ bridge->info = NULL;
+ module_put(bridge->dev.parent->driver->owner);
+ mutex_unlock(&bridge->mutex);
+ put_device(&bridge->dev);
+}
+EXPORT_SYMBOL_GPL(fpga_bridge_put);
+
+/**
+ * fpga_bridges_enable - enable bridges in a list
+ * @bridge_list: list of FPGA bridges
+ *
+ * Enable each bridge in the list. If list is empty, do nothing.
+ *
+ * Return 0 for success or empty bridge list; return error code otherwise.
+ */
+int fpga_bridges_enable(struct list_head *bridge_list)
+{
+ struct fpga_bridge *bridge;
+ struct list_head *node;
+ int ret;
+
+ list_for_each(node, bridge_list) {
+ bridge = list_entry(node, struct fpga_bridge, node);
+ ret = fpga_bridge_enable(bridge);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_bridges_enable);
+
+/**
+ * fpga_bridges_disable - disable bridges in a list
+ *
+ * @bridge_list: list of FPGA bridges
+ *
+ * Disable each bridge in the list. If list is empty, do nothing.
+ *
+ * Return 0 for success or empty bridge list; return error code otherwise.
+ */
+int fpga_bridges_disable(struct list_head *bridge_list)
+{
+ struct fpga_bridge *bridge;
+ struct list_head *node;
+ int ret;
+
+ list_for_each(node, bridge_list) {
+ bridge = list_entry(node, struct fpga_bridge, node);
+ ret = fpga_bridge_disable(bridge);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_bridges_disable);
+
+/**
+ * fpga_bridges_put - put bridges
+ *
+ * @bridge_list: list of FPGA bridges
+ *
+ * For each bridge in the list, put the bridge and remove it from the list.
+ * If list is empty, do nothing.
+ */
+void fpga_bridges_put(struct list_head *bridge_list)
+{
+ struct fpga_bridge *bridge;
+ struct list_head *node, *next;
+ unsigned long flags;
+
+ list_for_each_safe(node, next, bridge_list) {
+ bridge = list_entry(node, struct fpga_bridge, node);
+
+ fpga_bridge_put(bridge);
+
+ spin_lock_irqsave(&bridge_list_lock, flags);
+ list_del(&bridge->node);
+ spin_unlock_irqrestore(&bridge_list_lock, flags);
+ }
+}
+EXPORT_SYMBOL_GPL(fpga_bridges_put);
+
+/**
+ * fpga_bridges_get_to_list - get a bridge, add it to a list
+ *
+ * @np: node pointer of a FPGA bridge
+ * @info: fpga image specific information
+ * @bridge_list: list of FPGA bridges
+ *
+ * Get an exclusive reference to the bridge and and it to the list.
+ *
+ * Return 0 for success, error code from of_fpga_bridge_get() othewise.
+ */
+int fpga_bridge_get_to_list(struct device_node *np,
+ struct fpga_image_info *info,
+ struct list_head *bridge_list)
+{
+ struct fpga_bridge *bridge;
+ unsigned long flags;
+
+ bridge = of_fpga_bridge_get(np, info);
+ if (IS_ERR(bridge))
+ return PTR_ERR(bridge);
+
+ spin_lock_irqsave(&bridge_list_lock, flags);
+ list_add(&bridge->node, bridge_list);
+ spin_unlock_irqrestore(&bridge_list_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);
+
+static ssize_t name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct fpga_bridge *bridge = to_fpga_bridge(dev);
+
+ return sprintf(buf, "%s\n", bridge->name);
+}
+
+static ssize_t state_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct fpga_bridge *bridge = to_fpga_bridge(dev);
+ int enable = 1;
+
+ if (bridge->br_ops && bridge->br_ops->enable_show)
+ enable = bridge->br_ops->enable_show(bridge);
+
+ return sprintf(buf, "%s\n", enable ? "enabled" : "disabled");
+}
+
+static DEVICE_ATTR_RO(name);
+static DEVICE_ATTR_RO(state);
+
+static struct attribute *fpga_bridge_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_state.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(fpga_bridge);
+
+/**
+ * fpga_bridge_register - register a fpga bridge driver
+ * @dev: FPGA bridge device from pdev
+ * @name: FPGA bridge name
+ * @br_ops: pointer to structure of fpga bridge ops
+ * @priv: FPGA bridge private data
+ *
+ * Return: 0 for success, error code otherwise.
+ */
+int fpga_bridge_register(struct device *dev, const char *name,
+ const struct fpga_bridge_ops *br_ops, void *priv)
+{
+ struct fpga_bridge *bridge;
+ int id, ret = 0;
+
+ if (!name || !strlen(name)) {
+ dev_err(dev, "Attempt to register with no name!\n");
+ return -EINVAL;
+ }
+
+ bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
+ if (!bridge)
+ return -ENOMEM;
+
+ id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
+ if (id < 0) {
+ ret = id;
+ goto error_kfree;
+ }
+
+ mutex_init(&bridge->mutex);
+ INIT_LIST_HEAD(&bridge->node);
+
+ bridge->name = name;
+ bridge->br_ops = br_ops;
+ bridge->priv = priv;
+
+ device_initialize(&bridge->dev);
+ bridge->dev.class = fpga_bridge_class;
+ bridge->dev.parent = dev;
+ bridge->dev.of_node = dev->of_node;
+ bridge->dev.id = id;
+ dev_set_drvdata(dev, bridge);
+
+ ret = dev_set_name(&bridge->dev, "br%d", id);
+ if (ret)
+ goto error_device;
+
+ ret = device_add(&bridge->dev);
+ if (ret)
+ goto error_device;
+
+ of_platform_populate(dev->of_node, NULL, NULL, dev);
+
+ dev_info(bridge->dev.parent, "fpga bridge [%s] registered\n",
+ bridge->name);
+
+ return 0;
+
+error_device:
+ ida_simple_remove(&fpga_bridge_ida, id);
+error_kfree:
+ kfree(bridge);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(fpga_bridge_register);
+
+/**
+ * fpga_bridge_unregister - unregister a fpga bridge driver
+ * @dev: FPGA bridge device from pdev
+ */
+void fpga_bridge_unregister(struct device *dev)
+{
+ struct fpga_bridge *bridge = dev_get_drvdata(dev);
+
+ /*
+ * If the low level driver provides a method for putting bridge into
+ * a desired state upon unregister, do it.
+ */
+ if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove)
+ bridge->br_ops->fpga_bridge_remove(bridge);
+
+ device_unregister(&bridge->dev);
+}
+EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
+
+static void fpga_bridge_dev_release(struct device *dev)
+{
+ struct fpga_bridge *bridge = to_fpga_bridge(dev);
+
+ ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
+ kfree(bridge);
+}
+
+static int __init fpga_bridge_dev_init(void)
+{
+ spin_lock_init(&bridge_list_lock);
+
+ fpga_bridge_class = class_create(THIS_MODULE, "fpga_bridge");
+ if (IS_ERR(fpga_bridge_class))
+ return PTR_ERR(fpga_bridge_class);
+
+ fpga_bridge_class->dev_groups = fpga_bridge_groups;
+ fpga_bridge_class->dev_release = fpga_bridge_dev_release;
+
+ return 0;
+}
+
+static void __exit fpga_bridge_dev_exit(void)
+{
+ class_destroy(fpga_bridge_class);
+ ida_destroy(&fpga_bridge_ida);
+}
+
+MODULE_DESCRIPTION("FPGA Bridge Driver");
+MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
+MODULE_LICENSE("GPL v2");
+
+subsys_initcall(fpga_bridge_dev_init);
+module_exit(fpga_bridge_dev_exit);
diff --git a/include/linux/fpga/fpga-bridge.h b/include/linux/fpga/fpga-bridge.h
new file mode 100644
index 000000000000..dba6e3c697c7
--- /dev/null
+++ b/include/linux/fpga/fpga-bridge.h
@@ -0,0 +1,60 @@
+#include <linux/device.h>
+#include <linux/fpga/fpga-mgr.h>
+
+#ifndef _LINUX_FPGA_BRIDGE_H
+#define _LINUX_FPGA_BRIDGE_H
+
+struct fpga_bridge;
+
+/**
+ * struct fpga_bridge_ops - ops for low level FPGA bridge drivers
+ * @enable_show: returns the FPGA bridge's status
+ * @enable_set: set a FPGA bridge as enabled or disabled
+ * @fpga_bridge_remove: set FPGA into a specific state during driver remove
+ */
+struct fpga_bridge_ops {
+ int (*enable_show)(struct fpga_bridge *bridge);
+ int (*enable_set)(struct fpga_bridge *bridge, bool enable);
+ void (*fpga_bridge_remove)(struct fpga_bridge *bridge);
+};
+
+/**
+ * struct fpga_bridge - FPGA bridge structure
+ * @name: name of low level FPGA bridge
+ * @dev: FPGA bridge device
+ * @mutex: enforces exclusive reference to bridge
+ * @br_ops: pointer to struct of FPGA bridge ops
+ * @info: fpga image specific information
+ * @node: FPGA bridge list node
+ * @priv: low level driver private date
+ */
+struct fpga_bridge {
+ const char *name;
+ struct device dev;
+ struct mutex mutex; /* for exclusive reference to bridge */
+ const struct fpga_bridge_ops *br_ops;
+ struct fpga_image_info *info;
+ struct list_head node;
+ void *priv;
+};
+
+#define to_fpga_bridge(d) container_of(d, struct fpga_bridge, dev)
+
+struct fpga_bridge *of_fpga_bridge_get(struct device_node *node,
+ struct fpga_image_info *info);
+void fpga_bridge_put(struct fpga_bridge *bridge);
+int fpga_bridge_enable(struct fpga_bridge *bridge);
+int fpga_bridge_disable(struct fpga_bridge *bridge);
+
+int fpga_bridges_enable(struct list_head *bridge_list);
+int fpga_bridges_disable(struct list_head *bridge_list);
+void fpga_bridges_put(struct list_head *bridge_list);
+int fpga_bridge_get_to_list(struct device_node *np,
+ struct fpga_image_info *info,
+ struct list_head *bridge_list);
+
+int fpga_bridge_register(struct device *dev, const char *name,
+ const struct fpga_bridge_ops *br_ops, void *priv);
+void fpga_bridge_unregister(struct device *dev);
+
+#endif /* _LINUX_FPGA_BRIDGE_H */