mic_bus.c
/*
* Intel MIC Platform Software Stack (MPSS)
*
* Copyright(c) 2014 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that 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.
*
* The full GNU General Public License is included in this distribution in
* the file called "COPYING".
*
* Intel MIC Bus driver.
*
* This implementation is very similar to the the virtio bus driver
* implementation @ drivers/virtio/virtio.c
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/mic_bus.h>
/* Unique numbering for mbus devices. */
static DEFINE_IDA(mbus_index_ida);
static ssize_t device_show(struct device *d,
struct device_attribute *attr, char *buf)
{
struct mbus_device *dev = dev_to_mbus(d);
return sprintf(buf, "0x%04x\n", dev->id.device);
}
static DEVICE_ATTR_RO(device);
static ssize_t vendor_show(struct device *d,
struct device_attribute *attr, char *buf)
{
struct mbus_device *dev = dev_to_mbus(d);
return sprintf(buf, "0x%04x\n", dev->id.vendor);
}
static DEVICE_ATTR_RO(vendor);
static ssize_t modalias_show(struct device *d,
struct device_attribute *attr, char *buf)
{
struct mbus_device *dev = dev_to_mbus(d);
return sprintf(buf, "mbus:d%08Xv%08X\n",
dev->id.device, dev->id.vendor);
}
static DEVICE_ATTR_RO(modalias);
static struct attribute *mbus_dev_attrs[] = {
&dev_attr_device.attr,
&dev_attr_vendor.attr,
&dev_attr_modalias.attr,
NULL,
};
ATTRIBUTE_GROUPS(mbus_dev);
static inline int mbus_id_match(const struct mbus_device *dev,
const struct mbus_device_id *id)
{
if (id->device != dev->id.device && id->device != MBUS_DEV_ANY_ID)
return 0;
return id->vendor == MBUS_DEV_ANY_ID || id->vendor == dev->id.vendor;
}
/*
* This looks through all the IDs a driver claims to support. If any of them
* match, we return 1 and the kernel will call mbus_dev_probe().
*/
static int mbus_dev_match(struct device *dv, struct device_driver *dr)
{
unsigned int i;
struct mbus_device *dev = dev_to_mbus(dv);
const struct mbus_device_id *ids;
ids = drv_to_mbus(dr)->id_table;
for (i = 0; ids[i].device; i++)
if (mbus_id_match(dev, &ids[i]))
return 1;
return 0;
}
static int mbus_uevent(struct device *dv, struct kobj_uevent_env *env)
{
struct mbus_device *dev = dev_to_mbus(dv);
return add_uevent_var(env, "MODALIAS=mbus:d%08Xv%08X",
dev->id.device, dev->id.vendor);
}
static int mbus_dev_probe(struct device *d)
{
int err;
struct mbus_device *dev = dev_to_mbus(d);
struct mbus_driver *drv = drv_to_mbus(dev->dev.driver);
err = drv->probe(dev);
if (!err)
if (drv->scan)
drv->scan(dev);
return err;
}
static int mbus_dev_remove(struct device *d)
{
struct mbus_device *dev = dev_to_mbus(d);
struct mbus_driver *drv = drv_to_mbus(dev->dev.driver);
drv->remove(dev);
return 0;
}
static struct bus_type mic_bus = {
.name = "mic_bus",
.match = mbus_dev_match,
.dev_groups = mbus_dev_groups,
.uevent = mbus_uevent,
.probe = mbus_dev_probe,
.remove = mbus_dev_remove,
};
int mbus_register_driver(struct mbus_driver *driver)
{
driver->driver.bus = &mic_bus;
return driver_register(&driver->driver);
}
EXPORT_SYMBOL_GPL(mbus_register_driver);
void mbus_unregister_driver(struct mbus_driver *driver)
{
driver_unregister(&driver->driver);
}
EXPORT_SYMBOL_GPL(mbus_unregister_driver);
static void mbus_release_dev(struct device *d)
{
struct mbus_device *mbdev = dev_to_mbus(d);
kfree(mbdev);
}
struct mbus_device *
mbus_register_device(struct device *pdev, int id, struct dma_map_ops *dma_ops,
struct mbus_hw_ops *hw_ops, void __iomem *mmio_va)
{
int ret;
struct mbus_device *mbdev;
mbdev = kzalloc(sizeof(*mbdev), GFP_KERNEL);
if (!mbdev)
return ERR_PTR(-ENOMEM);
mbdev->mmio_va = mmio_va;
mbdev->dev.parent = pdev;
mbdev->id.device = id;
mbdev->id.vendor = MBUS_DEV_ANY_ID;
mbdev->dev.archdata.dma_ops = dma_ops;
mbdev->dev.dma_mask = &mbdev->dev.coherent_dma_mask;
dma_set_mask(&mbdev->dev, DMA_BIT_MASK(64));
mbdev->dev.release = mbus_release_dev;
mbdev->hw_ops = hw_ops;
mbdev->dev.bus = &mic_bus;
/* Assign a unique device index and hence name. */
ret = ida_simple_get(&mbus_index_ida, 0, 0, GFP_KERNEL);
if (ret < 0)
goto free_mbdev;
mbdev->index = ret;
dev_set_name(&mbdev->dev, "mbus-dev%u", mbdev->index);
/*
* device_register() causes the bus infrastructure to look for a
* matching driver.
*/
ret = device_register(&mbdev->dev);
if (ret)
goto ida_remove;
return mbdev;
ida_remove:
ida_simple_remove(&mbus_index_ida, mbdev->index);
free_mbdev:
kfree(mbdev);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(mbus_register_device);
void mbus_unregister_device(struct mbus_device *mbdev)
{
int index = mbdev->index; /* save for after device release */
device_unregister(&mbdev->dev);
ida_simple_remove(&mbus_index_ida, index);
}
EXPORT_SYMBOL_GPL(mbus_unregister_device);
static int __init mbus_init(void)
{
return bus_register(&mic_bus);
}
static void __exit mbus_exit(void)
{
bus_unregister(&mic_bus);
ida_destroy(&mbus_index_ida);
}
core_initcall(mbus_init);
module_exit(mbus_exit);
MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("Intel(R) MIC Bus driver");
MODULE_LICENSE("GPL v2");