1 files changed, 395 insertions, 0 deletions

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);