| /* |
| * FPGA Bridge Framework Driver |
| * |
| * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved. |
| * Copyright (C) 2017 Intel Corporation |
| * |
| * 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*/ |
| static 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); |
| |
| static struct fpga_bridge *__fpga_bridge_get(struct device *dev, |
| struct fpga_image_info *info) |
| { |
| struct fpga_bridge *bridge; |
| int ret = -ENODEV; |
| |
| bridge = to_fpga_bridge(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); |
| } |
| |
| /** |
| * 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; |
| |
| dev = class_find_device(fpga_bridge_class, NULL, np, |
| fpga_bridge_of_node_match); |
| if (!dev) |
| return ERR_PTR(-ENODEV); |
| |
| return __fpga_bridge_get(dev, info); |
| } |
| EXPORT_SYMBOL_GPL(of_fpga_bridge_get); |
| |
| static int fpga_bridge_dev_match(struct device *dev, const void *data) |
| { |
| return dev->parent == data; |
| } |
| |
| /** |
| * fpga_bridge_get - get an exclusive reference to a fpga bridge |
| * @dev: parent device that fpga bridge was registered with |
| * |
| * Given a device, get an exclusive reference to a fpga bridge. |
| * |
| * Return: fpga manager struct or IS_ERR() condition containing error code. |
| */ |
| struct fpga_bridge *fpga_bridge_get(struct device *dev, |
| struct fpga_image_info *info) |
| { |
| struct device *bridge_dev; |
| |
| bridge_dev = class_find_device(fpga_bridge_class, NULL, dev, |
| fpga_bridge_dev_match); |
| if (!bridge_dev) |
| return ERR_PTR(-ENODEV); |
| |
| return __fpga_bridge_get(bridge_dev, info); |
| } |
| EXPORT_SYMBOL_GPL(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; |
| int ret; |
| |
| list_for_each_entry(bridge, bridge_list, 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; |
| int ret; |
| |
| list_for_each_entry(bridge, bridge_list, 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, *next; |
| unsigned long flags; |
| |
| list_for_each_entry_safe(bridge, next, bridge_list, 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); |
| |
| /** |
| * of_fpga_bridge_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 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 and it to the list. |
| * |
| * Return 0 for success, error code from fpga_bridge_get() othewise. |
| */ |
| 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 = fpga_bridge_get(dev, 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.groups = br_ops->groups; |
| 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@kernel.org>"); |
| MODULE_LICENSE("GPL v2"); |
| |
| subsys_initcall(fpga_bridge_dev_init); |
| module_exit(fpga_bridge_dev_exit); |