// SPDX-License-Identifier: GPL-2.0 /* * FPGA Bridge Framework Driver * * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved. * Copyright (C) 2017 Intel Corporation */ #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 DEFINE_SPINLOCK(bridge_list_lock); /** * 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 an fpga bridge * * @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 an 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_by_of_node(fpga_bridge_class, np); 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 an fpga bridge * @dev: parent device that fpga bridge was registered with * @info: fpga manager info * * 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 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 an FPGA bridge * @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 of_fpga_bridge_get() otherwise. */ 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 = 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 state = 1; if (bridge->br_ops && bridge->br_ops->enable_show) { state = bridge->br_ops->enable_show(bridge); if (state < 0) return state; } return sysfs_emit(buf, "%s\n", state ? "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 - 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 * * Return: struct fpga_bridge pointer or ERR_PTR() */ struct fpga_bridge * fpga_bridge_register(struct device *parent, const char *name, const struct fpga_bridge_ops *br_ops, void *priv) { struct fpga_bridge *bridge; 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(parent, "Attempt to register with no name!\n"); return ERR_PTR(-EINVAL); } bridge = kzalloc(sizeof(*bridge), GFP_KERNEL); if (!bridge) return ERR_PTR(-ENOMEM); id = ida_alloc(&fpga_bridge_ida, 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; 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; of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev); ret = dev_set_name(&bridge->dev, "br%d", id); if (ret) goto error_device; ret = device_register(&bridge->dev); if (ret) { put_device(&bridge->dev); return ERR_PTR(ret); } return bridge; error_device: ida_free(&fpga_bridge_ida, id); error_kfree: kfree(bridge); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(fpga_bridge_register); /** * 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 fpga_bridge *bridge) { /* * 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_free(&fpga_bridge_ida, bridge->dev.id); kfree(bridge); } static int __init fpga_bridge_dev_init(void) { 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);