diff options
| -rw-r--r-- | drivers/fpga/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/fpga/Makefile | 3 | ||||
| -rw-r--r-- | drivers/fpga/fpga-bridge.c | 395 | ||||
| -rw-r--r-- | include/linux/fpga/fpga-bridge.h | 60 |
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 */ |