On Tue, Oct 27, 2015 at 05:09:13PM -0500, atull@xxxxxxxxxxxxxxxxxxxxx wrote: > From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> > > This framework adds API functions for enabling/ > disabling FPGA bridges under kernel control. > > This allows the Linux kernel to disable FPGA bridges > during FPGA reprogramming and to enable FPGA bridges > when FPGA reprogramming is done. This framework is > be manufacturer-agnostic, allowing it to be used in > interfaces that use the FPGA Manager Framework to > reprogram FPGAs. > > The functions are: > * of_fpga_bridge_get > * fpga_bridge_put > Get/put a reference to a FPGA bridge. > > * fpga_bridge_enable > * fpga_bridge_disable > Enable/Disable traffic through a bridge. > > * fpga_bridge_register > * fpga_bridge_unregister > Register/unregister a device-specific low level FPGA > Bridge driver. > > Signed-off-by: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> > --- > v2: Minor cleanup > v12: Bump version to line up with simple fpga bus > Remove sysfs > Improve get/put functions, get the low level driver too. > Clean up class implementation > Add kernel doc documentation > Rename (un)register_fpga_bridge -> fpga_bridge_(un)register > --- > drivers/fpga/Kconfig | 7 ++ > drivers/fpga/Makefile | 3 + > drivers/fpga/fpga-bridge.c | 242 ++++++++++++++++++++++++++++++++++++++ > include/linux/fpga/fpga-bridge.h | 49 ++++++++ > 4 files changed, 301 insertions(+) > create mode 100644 drivers/fpga/fpga-bridge.c > create mode 100644 include/linux/fpga/fpga-bridge.h > > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig > index e8f5453..143072b 100644 > --- a/drivers/fpga/Kconfig > +++ b/drivers/fpga/Kconfig > @@ -32,6 +32,13 @@ config FPGA_MGR_SOCFPGA_A10 > help > FPGA manager driver support for Altera Arria10 SoCFPGA. > > +config FPGA_BRIDGE > + bool "FPGA Bridge Drivers" > + 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 0385622..9302662 100644 > --- a/drivers/fpga/Makefile > +++ b/drivers/fpga/Makefile > @@ -9,5 +9,8 @@ obj-$(CONFIG_FPGA) += fpga-mgr.o > obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o > obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10) += socfpga-a10.o > > +# FPGA Bridge Drivers > +obj-$(CONFIG_FPGA_BRIDGE) += fpga-bridge.o > + > # High Level Interfaces > obj-$(CONFIG_SIMPLE_FPGA_BUS) += simple-fpga-bus.o > diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c > new file mode 100644 > index 0000000..c135988 > --- /dev/null > +++ b/drivers/fpga/fpga-bridge.c > @@ -0,0 +1,242 @@ > +/* > + * fpga bridge driver > + * > + * Copyright (C) 2013-2015 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> > + > +static DEFINE_IDA(fpga_bridge_ida); > +static struct class *fpga_bridge_class; > + > +/** > + * fpga_bridge_enable > + * @bridge: fpga bridge > + * > + * Enable transactions on the bridge > + * > + * Return: 0 for success, error code otherwise. > + */ > +int fpga_bridge_enable(struct fpga_bridge *bridge) > +{ > + pr_err("%s %s\n", __func__, dev_name(&bridge->dev)); Please clean this... > + > + return bridge->br_ops->enable_set(bridge, 1); > +} > +EXPORT_SYMBOL_GPL(fpga_bridge_enable); > + > +/** > + * fpga_bridge_disable > + * @bridge: fpga bridge > + * > + * Disable transactions on the bridge > + * > + * Return: 0 for success, error code otherwise. > + */ > +int fpga_bridge_disable(struct fpga_bridge *bridge) > +{ > + pr_err("%s %s\n", __func__, dev_name(&bridge->dev)); and this up. > + > + return bridge->br_ops->enable_set(bridge, 0); > +} > +EXPORT_SYMBOL_GPL(fpga_bridge_disable); > + > +static int fpga_bridge_of_node_match(struct device *dev, const void *data) > +{ > + return dev->of_node == data; > +} > + > +/** > + * of_fpga_bridge_get - get an exclusive reference to a fpga bridge > + * @node: device node > + * > + * Given a device node, get an exclusive reference to a fpga bridge. > + * > + * Returns a fpga manager struct or IS_ERR() condition containing errno. > + */ > +struct fpga_bridge *of_fpga_bridge_get(struct device_node *node) > +{ > + struct device *dev; > + struct fpga_bridge *bridge; > + int ret = -ENODEV; > + > + dev = class_find_device(fpga_bridge_class, NULL, node, > + fpga_bridge_of_node_match); > + if (!dev) > + return ERR_PTR(-ENODEV); > + > + bridge = to_fpga_bridge(dev); > + if (!bridge) > + goto err_dev; > + > + if (!mutex_trylock(&bridge->mutex)) { > + ret = -EBUSY; > + goto err_dev; > + } > + > + if (!try_module_get(dev->parent->driver->owner)) > + goto err_ll_mod; > + > + 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 fpga bridge > + * @bridge: fpga bridge > + */ > +void fpga_bridge_put(struct fpga_bridge *bridge) > +{ > + module_put(bridge->dev.parent->driver->owner); > + mutex_unlock(&bridge->mutex); > + put_device(&bridge->dev); > +} > +EXPORT_SYMBOL_GPL(fpga_bridge_put); > + > +/** > + * 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 on success, negative error code otherwise. > + */ > +int fpga_bridge_register(struct device *dev, const char *name, > + struct fpga_bridge_ops *br_ops, void *priv) > +{ > + struct fpga_bridge *bridge; > + const char *dt_label; > + int id, ret = 0; > + > + if (!br_ops || !br_ops->enable_set || !br_ops->enable_show) { > + dev_err(dev, "Attempt to register without fpga_bridge_ops\n"); > + return -EINVAL; > + } > + > + 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); > + > + 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); > + > + dt_label = of_get_property(bridge->dev.of_node, "label", NULL); > + if (dt_label) > + ret = dev_set_name(&bridge->dev, "%s", dt_label); > + else > + ret = dev_set_name(&bridge->dev, "br%d", id); > + if (ret) > + goto error_device; > + > + ret = device_add(&bridge->dev); > + if (ret) > + goto error_device; > + > + 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); > + > +void fpga_bridge_unregister(struct device *dev) > +{ > + struct fpga_bridge *bridge = dev_get_drvdata(dev); > + > + dev_info(&bridge->dev, "%s : %s\n", __func__, bridge->name); Is this necessary information? > + > + /* > + * If the low level driver provides a method for putting bridge into > + * a desired state upon unregister, do it. > + */ > + if (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) > +{ > + pr_info("FPGA bridge framework driver\n"); Dito. IMHO unnecessary log spam. Maybe change this to dbg? > + > + 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_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@xxxxxxxxxxxxxxxxxxxxx>"); > +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 0000000..da6791e > --- /dev/null > +++ b/include/linux/fpga/fpga-bridge.h > @@ -0,0 +1,49 @@ > +#include <linux/cdev.h> You don't seem to use this. > +#include <linux/device.h> > +#include <linux/platform_device.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 > + * @br_ops: pointer to struct of fpga bridge ops > + * @priv: low level driver private date > + */ > +struct fpga_bridge { > + const char *name; > + struct device dev; > + struct mutex mutex; > + struct fpga_bridge_ops *br_ops; > + 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); > +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_bridge_register(struct device *dev, const char *name, > + struct fpga_bridge_ops *br_ops, void *priv); > +void fpga_bridge_unregister(struct device *dev); > + > +#endif /* _LINUX_FPGA_BRIDGE_H */ -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
