1 files changed, 170 insertions, 112 deletions

diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
index 9651aa56244a..8ef395b49bf8 100644
--- a/drivers/fpga/fpga-bridge.c
+++ b/drivers/fpga/fpga-bridge.c
@@ -1,19 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * 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/>.
+ *  Copyright (C) 2017 Intel Corporation
  */
 #include <linux/fpga/fpga-bridge.h>
 #include <linux/idr.h>
@@ -24,15 +14,10 @@
 #include <linux/spinlock.h>
 
 static DEFINE_IDA(fpga_bridge_ida);
-static struct class *fpga_bridge_class;
+static const struct class fpga_bridge_class;
 
 /* Lock for adding/removing bridges to linked lists*/
-static spinlock_t bridge_list_lock;
-
-static int fpga_bridge_of_node_match(struct device *dev, const void *data)
-{
-	return dev->of_node == data;
-}
+static DEFINE_SPINLOCK(bridge_list_lock);
 
 /**
  * fpga_bridge_enable - Enable transactions on the bridge
@@ -45,7 +30,7 @@ int fpga_bridge_enable(struct fpga_bridge *bridge)
 {
 	dev_dbg(&bridge->dev, "enable\n");
 
-	if (bridge->br_ops && bridge->br_ops->enable_set)
+	if (bridge->br_ops->enable_set)
 		return bridge->br_ops->enable_set(bridge, 1);
 
 	return 0;
@@ -63,61 +48,96 @@ int fpga_bridge_disable(struct fpga_bridge *bridge)
 {
 	dev_dbg(&bridge->dev, "disable\n");
 
-	if (bridge->br_ops && bridge->br_ops->enable_set)
+	if (bridge->br_ops->enable_set)
 		return bridge->br_ops->enable_set(bridge, 0);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_disable);
 
+static struct fpga_bridge *__fpga_bridge_get(struct device *bridge_dev,
+					     struct fpga_image_info *info)
+{
+	struct fpga_bridge *bridge;
+
+	bridge = to_fpga_bridge(bridge_dev);
+
+	bridge->info = info;
+
+	if (!mutex_trylock(&bridge->mutex))
+		return ERR_PTR(-EBUSY);
+
+	if (!try_module_get(bridge->br_ops_owner)) {
+		mutex_unlock(&bridge->mutex);
+		return ERR_PTR(-ENODEV);
+	}
+
+	dev_dbg(&bridge->dev, "get\n");
+
+	return bridge;
+}
+
 /**
- * of_fpga_bridge_get - get an exclusive reference to a fpga bridge
+ * of_fpga_bridge_get - get an exclusive reference to an fpga bridge
  *
- * @np: node pointer of a FPGA bridge
- * @info: fpga image specific information
+ * @np: node pointer of an 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.
+ * Return:
+ * * fpga_bridge struct pointer if successful.
+ * * -EBUSY if someone already has a reference to the bridge.
+ * * -ENODEV if @np is not an FPGA Bridge or can't take parent driver refcount.
  */
 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;
+	struct device *bridge_dev;
 
-	dev = class_find_device(fpga_bridge_class, NULL, np,
-				fpga_bridge_of_node_match);
-	if (!dev)
-		goto err_dev;
+	bridge_dev = class_find_device_by_of_node(&fpga_bridge_class, np);
+	if (!bridge_dev)
+		return ERR_PTR(-ENODEV);
 
-	bridge = to_fpga_bridge(dev);
-	if (!bridge)
-		goto err_dev;
+	bridge = __fpga_bridge_get(bridge_dev, info);
+	if (IS_ERR(bridge))
+		put_device(bridge_dev);
 
-	bridge->info = info;
+	return bridge;
+}
+EXPORT_SYMBOL_GPL(of_fpga_bridge_get);
 
-	if (!mutex_trylock(&bridge->mutex)) {
-		ret = -EBUSY;
-		goto err_dev;
-	}
+static int fpga_bridge_dev_match(struct device *dev, const void *data)
+{
+	return dev->parent == data;
+}
+
+/**
+ * fpga_bridge_get - get an exclusive reference to an fpga bridge
+ * @dev:	parent device that fpga bridge was registered with
+ * @info:	fpga image specific information
+ *
+ * Given a device, get an exclusive reference to an fpga bridge.
+ *
+ * Return: fpga bridge struct or IS_ERR() condition containing error code.
+ */
+struct fpga_bridge *fpga_bridge_get(struct device *dev,
+				    struct fpga_image_info *info)
+{
+	struct fpga_bridge *bridge;
+	struct device *bridge_dev;
 
-	if (!try_module_get(dev->parent->driver->owner))
-		goto err_ll_mod;
+	bridge_dev = class_find_device(&fpga_bridge_class, NULL, dev,
+				       fpga_bridge_dev_match);
+	if (!bridge_dev)
+		return ERR_PTR(-ENODEV);
 
-	dev_dbg(&bridge->dev, "get\n");
+	bridge = __fpga_bridge_get(bridge_dev, info);
+	if (IS_ERR(bridge))
+		put_device(bridge_dev);
 
 	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);
+EXPORT_SYMBOL_GPL(fpga_bridge_get);
 
 /**
  * fpga_bridge_put - release a reference to a bridge
@@ -129,7 +149,7 @@ void fpga_bridge_put(struct fpga_bridge *bridge)
 	dev_dbg(&bridge->dev, "put\n");
 
 	bridge->info = NULL;
-	module_put(bridge->dev.parent->driver->owner);
+	module_put(bridge->br_ops_owner);
 	mutex_unlock(&bridge->mutex);
 	put_device(&bridge->dev);
 }
@@ -139,9 +159,9 @@ 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.
+ * Enable each bridge in the list. If list is empty, do nothing.
  *
- * Return 0 for success or empty bridge list; return error code otherwise.
+ * Return: 0 for success or empty bridge list or an error code otherwise.
  */
 int fpga_bridges_enable(struct list_head *bridge_list)
 {
@@ -163,9 +183,9 @@ EXPORT_SYMBOL_GPL(fpga_bridges_enable);
  *
  * @bridge_list: list of FPGA bridges
  *
- * Disable each bridge in the list.  If list is empty, do nothing.
+ * Disable each bridge in the list. If list is empty, do nothing.
  *
- * Return 0 for success or empty bridge list; return error code otherwise.
+ * Return: 0 for success or empty bridge list or an error code otherwise.
  */
 int fpga_bridges_disable(struct list_head *bridge_list)
 {
@@ -206,24 +226,54 @@ void fpga_bridges_put(struct list_head *bridge_list)
 EXPORT_SYMBOL_GPL(fpga_bridges_put);
 
 /**
- * fpga_bridges_get_to_list - get a bridge, add it to a list
+ * of_fpga_bridge_get_to_list - get a bridge, add it to a list
  *
- * @np: node pointer of a FPGA bridge
+ * @np: node pointer of an 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.
+ * Get an exclusive reference to the bridge and it to the list.
  *
- * Return 0 for success, error code from of_fpga_bridge_get() othewise.
+ * Return: 0 for success, error code from of_fpga_bridge_get() otherwise.
  */
-int fpga_bridge_get_to_list(struct device_node *np,
+int of_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(of_fpga_bridge_get_to_list);
+
+/**
+ * fpga_bridge_get_to_list - given device, get a bridge, add it to a list
+ *
+ * @dev: FPGA bridge device
+ * @info: fpga image specific information
+ * @bridge_list: list of FPGA bridges
+ *
+ * Get an exclusive reference to the bridge and it to the list.
+ *
+ * Return: 0 for success, error code from fpga_bridge_get() otherwise.
+ */
+int fpga_bridge_get_to_list(struct device *dev,
 			    struct fpga_image_info *info,
 			    struct list_head *bridge_list)
 {
 	struct fpga_bridge *bridge;
 	unsigned long flags;
 
-	bridge = of_fpga_bridge_get(np, info);
+	bridge = fpga_bridge_get(dev, info);
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);
 
@@ -247,12 +297,15 @@ 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;
+	int state = 1;
 
-	if (bridge->br_ops && bridge->br_ops->enable_show)
-		enable = bridge->br_ops->enable_show(bridge);
+	if (bridge->br_ops->enable_show) {
+		state = bridge->br_ops->enable_show(bridge);
+		if (state < 0)
+			return state;
+	}
 
-	return sprintf(buf, "%s\n", enable ? "enabled" : "disabled");
+	return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
 }
 
 static DEVICE_ATTR_RO(name);
@@ -266,30 +319,38 @@ static struct attribute *fpga_bridge_attrs[] = {
 ATTRIBUTE_GROUPS(fpga_bridge);
 
 /**
- * fpga_bridge_register - register a fpga bridge driver
- * @dev:	FPGA bridge device from pdev
+ * __fpga_bridge_register - create and register an FPGA Bridge device
+ * @parent:	FPGA bridge device from pdev
  * @name:	FPGA bridge name
  * @br_ops:	pointer to structure of fpga bridge ops
  * @priv:	FPGA bridge private data
+ * @owner:	owner module containing the br_ops
  *
- * Return: 0 for success, error code otherwise.
+ * Return: struct fpga_bridge pointer or ERR_PTR()
  */
-int fpga_bridge_register(struct device *dev, const char *name,
-			 const struct fpga_bridge_ops *br_ops, void *priv)
+struct fpga_bridge *
+__fpga_bridge_register(struct device *parent, const char *name,
+		       const struct fpga_bridge_ops *br_ops,
+		       void *priv, struct module *owner)
 {
 	struct fpga_bridge *bridge;
-	int id, ret = 0;
+	int id, ret;
+
+	if (!br_ops) {
+		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
+		return ERR_PTR(-EINVAL);
+	}
 
 	if (!name || !strlen(name)) {
-		dev_err(dev, "Attempt to register with no name!\n");
-		return -EINVAL;
+		dev_err(parent, "Attempt to register with no name!\n");
+		return ERR_PTR(-EINVAL);
 	}
 
 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 	if (!bridge)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
+	id = ida_alloc(&fpga_bridge_ida, GFP_KERNEL);
 	if (id < 0) {
 		ret = id;
 		goto error_kfree;
@@ -300,52 +361,52 @@ int fpga_bridge_register(struct device *dev, const char *name,
 
 	bridge->name = name;
 	bridge->br_ops = br_ops;
+	bridge->br_ops_owner = owner;
 	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.groups = br_ops->groups;
+	bridge->dev.class = &fpga_bridge_class;
+	bridge->dev.parent = parent;
+	bridge->dev.of_node = parent->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);
+	ret = device_register(&bridge->dev);
+	if (ret) {
+		put_device(&bridge->dev);
+		return ERR_PTR(ret);
+	}
 
-	dev_info(bridge->dev.parent, "fpga bridge [%s] registered\n",
-		 bridge->name);
+	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
 
-	return 0;
+	return bridge;
 
 error_device:
-	ida_simple_remove(&fpga_bridge_ida, id);
+	ida_free(&fpga_bridge_ida, id);
 error_kfree:
 	kfree(bridge);
 
-	return ret;
+	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(fpga_bridge_register);
+EXPORT_SYMBOL_GPL(__fpga_bridge_register);
 
 /**
- * fpga_bridge_unregister - unregister a fpga bridge driver
- * @dev: FPGA bridge device from pdev
+ * fpga_bridge_unregister - unregister an FPGA bridge
+ *
+ * @bridge: FPGA bridge struct
+ *
+ * This function is intended for use in an FPGA bridge driver's remove function.
  */
-void fpga_bridge_unregister(struct device *dev)
+void fpga_bridge_unregister(struct fpga_bridge *bridge)
 {
-	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)
+	if (bridge->br_ops->fpga_bridge_remove)
 		bridge->br_ops->fpga_bridge_remove(bridge);
 
 	device_unregister(&bridge->dev);
@@ -356,32 +417,29 @@ 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);
+	ida_free(&fpga_bridge_ida, bridge->dev.id);
 	kfree(bridge);
 }
 
+static const struct class fpga_bridge_class = {
+	.name = "fpga_bridge",
+	.dev_groups = fpga_bridge_groups,
+	.dev_release = fpga_bridge_dev_release,
+};
+
 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;
+	return class_register(&fpga_bridge_class);
 }
 
 static void __exit fpga_bridge_dev_exit(void)
 {
-	class_destroy(fpga_bridge_class);
+	class_unregister(&fpga_bridge_class);
 	ida_destroy(&fpga_bridge_ida);
 }
 
 MODULE_DESCRIPTION("FPGA Bridge Driver");
-MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
+MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
 MODULE_LICENSE("GPL v2");
 
 subsys_initcall(fpga_bridge_dev_init);