This patch is a RFC patch which replaces the patch[1] which creates 'fpga-dev' class as container device. It introduces a 'fpga' bus type, and provides interfaces to create/destroy fpga bus devices. This fpga bus device only could be used as a container device, and no drivers needed for it.
There is no interface change, so this patch could be used together with other patches of the original patch set[2]. This following APIs are provided by FPGA Bus device framework: * fpga_dev_create Create fpga bus device under the given parent device. * fpga_dev_destroy Destroy fpga bus device The following sysfs files are created: * /sys/bus/fpga/devices/<fpga.x>/name Name of the fpga bus device. [1] http://marc.info/?l=linux-fpga&m=149844237209829&w=2 [2] http://marc.info/?l=linux-fpga&m=149844232609819&w=2 Signed-off-by: Wu Hao <hao...@intel.com> --- Documentation/ABI/testing/sysfs-bus-fpga | 5 ++ drivers/fpga/Kconfig | 6 ++ drivers/fpga/Makefile | 3 + drivers/fpga/fpga-dev.c | 132 +++++++++++++++++++++++++++++++ include/linux/fpga/fpga-dev.h | 31 ++++++++ 5 files changed, 177 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-fpga create mode 100644 drivers/fpga/fpga-dev.c create mode 100644 include/linux/fpga/fpga-dev.h diff --git a/Documentation/ABI/testing/sysfs-bus-fpga b/Documentation/ABI/testing/sysfs-bus-fpga new file mode 100644 index 0000000..414e946 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-fpga @@ -0,0 +1,5 @@ +What: /sys/bus/fpga/devices/<fpga.x>/name +Date: August 2017 +KernelVersion: 4.13 +Contact: Wu Hao <hao...@intel.com> +Description: Name of FPGA bus device diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig index d89eb52..b97a90e 100644 --- a/drivers/fpga/Kconfig +++ b/drivers/fpga/Kconfig @@ -12,6 +12,12 @@ config FPGA manager drivers. if FPGA +config FPGA_DEVICE + tristate "FPGA Bus Device Framework" + help + Say Y here if you want support for FPGA Bus devices from the + kernel. The FPGA Bus Device Framework adds a FPGA Bus type and + provide interfaces to create FPGA devices on the bus. config FPGA_REGION tristate "FPGA Region" diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile index 08fc728..3eb254e 100644 --- a/drivers/fpga/Makefile +++ b/drivers/fpga/Makefile @@ -5,6 +5,9 @@ # Core FPGA Manager Framework obj-$(CONFIG_FPGA) += fpga-mgr.o +# FPGA Bus Device Framework +obj-$(CONFIG_FPGA_DEVICE) += fpga-dev.o + # FPGA Manager Drivers obj-$(CONFIG_FPGA_MGR_ICE40_SPI) += ice40-spi.o obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o diff --git a/drivers/fpga/fpga-dev.c b/drivers/fpga/fpga-dev.c new file mode 100644 index 0000000..ddf67bb --- /dev/null +++ b/drivers/fpga/fpga-dev.c @@ -0,0 +1,132 @@ +/* + * FPGA Bus Device Framework Driver + * + * Copyright (C) 2017 Intel Corporation, Inc. + * + * This work is licensed under the terms of the GNU GPL version 2. See + * the COPYING file in the top-level directory. + */ +#include <linux/device.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/fpga/fpga-dev.h> + +static DEFINE_IDA(fpga_dev_ida); +static bool is_bus_registered; + +static void fpga_dev_release(struct device *dev) +{ + struct fpga_dev *fdev = to_fpga_dev(dev); + + ida_simple_remove(&fpga_dev_ida, fdev->dev.id); + kfree(fdev); +} + +static const struct device_type fpga_dev_type = { + .name = "fpga_dev", + .release = fpga_dev_release, +}; + +static ssize_t name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct fpga_dev *fdev = to_fpga_dev(dev); + + return sprintf(buf, "%s\n", fdev->name); +} +static DEVICE_ATTR_RO(name); + +static struct attribute *fpga_dev_attrs[] = { + &dev_attr_name.attr, + NULL, +}; +ATTRIBUTE_GROUPS(fpga_dev); + +static struct bus_type fpga_bus_type = { + .name = "fpga", +}; + +/** + * fpga_dev_create - create a fpga device on fpga bus + * @parent: parent device + * @name: fpga bus device name + * + * Return fpga_dev struct for success, error code otherwise. + */ +struct fpga_dev *fpga_dev_create(struct device *parent, const char *name) +{ + struct fpga_dev *fdev; + int id, ret = 0; + + if (WARN_ON(!is_bus_registered)) + return ERR_PTR(-ENODEV); + + if (!name || !strlen(name)) { + dev_err(parent, "Attempt to register with no name!\n"); + return ERR_PTR(-EINVAL); + } + + fdev = kzalloc(sizeof(*fdev), GFP_KERNEL); + if (!fdev) + return ERR_PTR(-ENOMEM); + + id = ida_simple_get(&fpga_dev_ida, 0, 0, GFP_KERNEL); + if (id < 0) { + ret = id; + goto error_kfree; + } + + fdev->name = name; + + device_initialize(&fdev->dev); + fdev->dev.type = &fpga_dev_type; + fdev->dev.bus = &fpga_bus_type; + fdev->dev.groups = fpga_dev_groups; + fdev->dev.parent = parent; + fdev->dev.id = id; + + ret = dev_set_name(&fdev->dev, "fpga.%d", id); + if (ret) + goto error_device; + + ret = device_add(&fdev->dev); + if (ret) + goto error_device; + + dev_dbg(fdev->dev.parent, "fpga bus device [%s] created\n", fdev->name); + + return fdev; + +error_device: + ida_simple_remove(&fpga_dev_ida, id); +error_kfree: + kfree(fdev); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(fpga_dev_create); + +static int __init fpga_bus_init(void) +{ + int ret; + + pr_info("FPGA Bus Device Framework\n"); + + ret = bus_register(&fpga_bus_type); + if (ret) + return ret; + + is_bus_registered = true; + return 0; +} + +static void __exit fpga_bus_exit(void) +{ + bus_unregister(&fpga_bus_type); +} + +MODULE_DESCRIPTION("FPGA Bus Device Framework"); +MODULE_LICENSE("GPL v2"); + +subsys_initcall(fpga_bus_init); +module_exit(fpga_bus_exit); diff --git a/include/linux/fpga/fpga-dev.h b/include/linux/fpga/fpga-dev.h new file mode 100644 index 0000000..7f6deb4 --- /dev/null +++ b/include/linux/fpga/fpga-dev.h @@ -0,0 +1,31 @@ +/* + * FPGA Bus Device Framework driver Header + * + * Copyright (C) 2017 Intel Corporation, Inc. + * + * This work is licensed under the terms of the GNU GPL version 2. See + * the COPYING file in the top-level directory. + */ +#ifndef _LINUX_FPGA_DEV_H +#define _LINUX_FPGA_DEV_H + +/** + * struct fpga_dev - fpga bus device structure + * @name: name of fpga bus device + * @dev: fpga bus device + */ +struct fpga_dev { + const char *name; + struct device dev; +}; + +#define to_fpga_dev(d) container_of(d, struct fpga_dev, dev) + +struct fpga_dev *fpga_dev_create(struct device *parent, const char *name); + +static inline void fpga_dev_destroy(struct fpga_dev *fdev) +{ + device_unregister(&fdev->dev); +} + +#endif -- 1.8.3.1
