usb.c

ReactOs中的USB驱动

	/* put into sysfs, with device and config specific files */
	err = device_add (&dev->dev);
	if (err)
		return err;
	usb_create_driverfs_dev_files (dev);

	/* Register all of the interfaces for this device with the driver core.
	 * Remember, interfaces get bound to drivers, not devices. */
	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
		struct usb_interface *interface = &dev->actconfig->interface[i];
		struct usb_interface_descriptor *desc;

		desc = &interface->altsetting [interface->act_altsetting].desc;
		interface->dev.parent = &dev->dev;
		interface->dev.driver = NULL;
		interface->dev.bus = &usb_bus_type;
		interface->dev.dma_mask = parent->dma_mask;
		sprintf (&interface->dev.bus_id[0], "%d-%s:%d",
			 dev->bus->busnum, dev->devpath,
			 desc->bInterfaceNumber);
		if (!desc->iInterface
				|| usb_string (dev, desc->iInterface,
					interface->dev.name,
					sizeof interface->dev.name) <= 0) {
			/* typically devices won't bother with interface
			 * descriptions; this is the normal case.  an
			 * interface's driver might describe it better.
			 * (also: iInterface is per-altsetting ...)
			 */
			sprintf (&interface->dev.name[0],
				"usb-%s-%s interface %d",
				dev->bus->bus_name, dev->devpath,
				desc->bInterfaceNumber);
			DPRINT1(".........................usb_new_device: %s\n", interface->dev.name);
		}
		dev_dbg (&dev->dev, "%s - registering interface %s\n", __FUNCTION__, interface->dev.bus_id);
		device_add (&interface->dev);
		usb_create_driverfs_intf_files (interface);
	}
	/* add a /proc/bus/usb entry */
	//usbfs_add_device(dev);

	return 0;
fail:
	dev->state = USB_STATE_DEFAULT;
	clear_bit(dev->devnum, dev->bus->devmap.devicemap);
	dev->devnum = -1;
	return err;
}

/**
 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_DMA_MAP
 * @dev: device the buffer will be used with
 * @size: requested buffer size
 * @mem_flags: affect whether allocation may block
 * @dma: used to return DMA address of buffer
 *
 * Return value is either null (indicating no buffer could be allocated), or
 * the cpu-space pointer to a buffer that may be used to perform DMA to the
 * specified device.  Such cpu-space buffers are returned along with the DMA
 * address (through the pointer provided).
 *
 * These buffers are used with URB_NO_DMA_MAP set in urb->transfer_flags to
 * avoid behaviors like using "DMA bounce buffers", or tying down I/O mapping
 * hardware for long idle periods.  The implementation varies between
 * platforms, depending on details of how DMA will work to this device.
 * Using these buffers also helps prevent cacheline sharing problems on
 * architectures where CPU caches are not DMA-coherent.
 *
 * When the buffer is no longer used, free it with usb_buffer_free().
 */
void *usb_buffer_alloc (
	struct usb_device *dev,
	size_t size,
	int mem_flags,
	dma_addr_t *dma
)
{
	if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc)
		return 0;
	return dev->bus->op->buffer_alloc (dev->bus, size, mem_flags, dma);
}

/**
 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
 * @dev: device the buffer was used with
 * @size: requested buffer size
 * @addr: CPU address of buffer
 * @dma: DMA address of buffer
 *
 * This reclaims an I/O buffer, letting it be reused.  The memory must have
 * been allocated using usb_buffer_alloc(), and the parameters must match
 * those provided in that allocation request. 
 */
void usb_buffer_free (
	struct usb_device *dev,
	size_t size,
	void *addr,
	dma_addr_t dma
)
{
	if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_free)
	    	return;
	dev->bus->op->buffer_free (dev->bus, size, addr, dma);
}

/**
 * usb_buffer_map - create DMA mapping(s) for an urb
 * @urb: urb whose transfer_buffer will be mapped
 *
 * Return value is either null (indicating no buffer could be mapped), or
 * the parameter.  URB_NO_DMA_MAP is added to urb->transfer_flags if the
 * operation succeeds.  If the device is connected to this system through
 * a non-DMA controller, this operation always succeeds.
 *
 * This call would normally be used for an urb which is reused, perhaps
 * as the target of a large periodic transfer, with usb_buffer_dmasync()
 * calls to synchronize memory and dma state.  It may not be used for
 * control requests.
 *
 * Reverse the effect of this call with usb_buffer_unmap().
 */
struct urb *usb_buffer_map (struct urb *urb)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!urb
			|| usb_pipecontrol (urb->pipe)
			|| !urb->dev
			|| !(bus = urb->dev->bus)
			|| !(controller = bus->controller))
		return 0;

	if (controller->dma_mask) {
		urb->transfer_dma = dma_map_single (controller,
			urb->transfer_buffer, urb->transfer_buffer_length,
			usb_pipein (urb->pipe)
				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
	// FIXME generic api broken like pci, can't report errors
	// if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
	} else
		urb->transfer_dma = ~0;
	urb->transfer_flags |= URB_NO_DMA_MAP;
	return urb;
}

/**
 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
 * @urb: urb whose transfer_buffer will be synchronized
 */
void usb_buffer_dmasync (struct urb *urb)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!urb
			|| !(urb->transfer_flags & URB_NO_DMA_MAP)
			|| !urb->dev
			|| !(bus = urb->dev->bus)
			|| !(controller = bus->controller))
		return;

	if (controller->dma_mask)
		dma_sync_single (controller,
			urb->transfer_dma, urb->transfer_buffer_length,
			usb_pipein (urb->pipe)
				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_unmap - free DMA mapping(s) for an urb
 * @urb: urb whose transfer_buffer will be unmapped
 *
 * Reverses the effect of usb_buffer_map().
 */
void usb_buffer_unmap (struct urb *urb)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!urb
			|| !(urb->transfer_flags & URB_NO_DMA_MAP)
			|| !urb->dev
			|| !(bus = urb->dev->bus)
			|| !(controller = bus->controller))
		return;

	if (controller->dma_mask)
		dma_unmap_single (controller,
			urb->transfer_dma, urb->transfer_buffer_length,
			usb_pipein (urb->pipe)
				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
	urb->transfer_flags &= ~URB_NO_DMA_MAP;
}

/**
 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
 * @dev: device to which the scatterlist will be mapped
 * @pipe: endpoint defining the mapping direction
 * @sg: the scatterlist to map
 * @nents: the number of entries in the scatterlist
 *
 * Return value is either < 0 (indicating no buffers could be mapped), or
 * the number of DMA mapping array entries in the scatterlist.
 *
 * The caller is responsible for placing the resulting DMA addresses from
 * the scatterlist into URB transfer buffer pointers, and for setting the
 * URB_NO_DMA_MAP transfer flag in each of those URBs.
 *
 * Top I/O rates come from queuing URBs, instead of waiting for each one
 * to complete before starting the next I/O.   This is particularly easy
 * to do with scatterlists.  Just allocate and submit one URB for each DMA
 * mapping entry returned, stopping on the first error or when all succeed.
 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
 *
 * This call would normally be used when translating scatterlist requests,
 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
 * may be able to coalesce mappings for improved I/O efficiency.
 *
 * Reverse the effect of this call with usb_buffer_unmap_sg().
 */
int usb_buffer_map_sg (struct usb_device *dev, unsigned pipe,
		struct scatterlist *sg, int nents)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!dev
			|| usb_pipecontrol (pipe)
			|| !(bus = dev->bus)
			|| !(controller = bus->controller)
			|| !controller->dma_mask)
		return -1;

	// FIXME generic api broken like pci, can't report errors
	return dma_map_sg (controller, sg, nents,
			usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
 * @dev: device to which the scatterlist will be mapped
 * @pipe: endpoint defining the mapping direction
 * @sg: the scatterlist to synchronize
 * @n_hw_ents: the positive return value from usb_buffer_map_sg
 *
 * Use this when you are re-using a scatterlist's data buffers for
 * another USB request.
 */
void usb_buffer_dmasync_sg (struct usb_device *dev, unsigned pipe,
		struct scatterlist *sg, int n_hw_ents)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!dev
			|| !(bus = dev->bus)
			|| !(controller = bus->controller)
			|| !controller->dma_mask)
		return;

	dma_sync_sg (controller, sg, n_hw_ents,
			usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}

/**
 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
 * @dev: device to which the scatterlist will be mapped
 * @pipe: endpoint defining the mapping direction
 * @sg: the scatterlist to unmap
 * @n_hw_ents: the positive return value from usb_buffer_map_sg
 *
 * Reverses the effect of usb_buffer_map_sg().
 */
void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe,
		struct scatterlist *sg, int n_hw_ents)
{
	struct usb_bus		*bus;
	struct device		*controller;

	if (!dev
			|| !(bus = dev->bus)
			|| !(controller = bus->controller)
			|| !controller->dma_mask)
		return;

	dma_unmap_sg (controller, sg, n_hw_ents,
			usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
}


struct bus_type usb_bus_type = {
	.name =		"usb",
	.match =	usb_device_match,
	.hotplug =	usb_hotplug,
};

#ifndef MODULE

static int __init usb_setup_disable(char *str)
{
	nousb = 1;
	return 1;
}

/* format to disable USB on kernel command line is: nousb */
__setup("nousb", usb_setup_disable);

#endif

/*
 * for external read access to <nousb>
 */
int STDCALL usb_disabled(void)
{
	return nousb;
}

/*
 * Init
 */
int STDCALL __init usb_init(void)
{
	if (nousb) {
		info("USB support disabled\n");
		return 0;
	}

	bus_register(&usb_bus_type);
	usb_major_init();
	usbfs_init();
	usb_hub_init();

	driver_register(&usb_generic_driver);

	return 0;
}

/*
 * Cleanup
 */
void STDCALL __exit usb_exit(void)
{
	/* This will matter if shutdown/reboot does exitcalls. */
	if (nousb)
		return;

	driver_unregister(&usb_generic_driver);
	usb_major_cleanup();
	usbfs_cleanup();
	usb_hub_cleanup();
	bus_unregister(&usb_bus_type);
}

subsys_initcall(usb_init);
module_exit(usb_exit);

/*
 * USB may be built into the kernel or be built as modules.
 * These symbols are exported for device (or host controller)
 * driver modules to use.
 */
EXPORT_SYMBOL(usb_epnum_to_ep_desc);

EXPORT_SYMBOL(usb_register);
EXPORT_SYMBOL(usb_deregister);
EXPORT_SYMBOL(usb_disabled);

EXPORT_SYMBOL(usb_device_probe);
EXPORT_SYMBOL(usb_device_remove);

EXPORT_SYMBOL(usb_alloc_dev);
EXPORT_SYMBOL(usb_put_dev);
EXPORT_SYMBOL(usb_get_dev);
EXPORT_SYMBOL(usb_hub_tt_clear_buffer);

EXPORT_SYMBOL(usb_driver_claim_interface);
EXPORT_SYMBOL(usb_interface_claimed);
EXPORT_SYMBOL(usb_driver_release_interface);
EXPORT_SYMBOL(usb_match_id);
EXPORT_SYMBOL(usb_find_interface);
EXPORT_SYMBOL(usb_ifnum_to_if);

EXPORT_SYMBOL(usb_new_device);
EXPORT_SYMBOL(usb_reset_device);
EXPORT_SYMBOL(usb_connect);
EXPORT_SYMBOL(usb_disconnect);

EXPORT_SYMBOL(__usb_get_extra_descriptor);

EXPORT_SYMBOL(usb_find_device);
EXPORT_SYMBOL(usb_get_current_frame_number);

EXPORT_SYMBOL (usb_buffer_alloc);
EXPORT_SYMBOL (usb_buffer_free);

EXPORT_SYMBOL (usb_buffer_map);
EXPORT_SYMBOL (usb_buffer_dmasync);
EXPORT_SYMBOL (usb_buffer_unmap);

EXPORT_SYMBOL (usb_buffer_map_sg);
EXPORT_SYMBOL (usb_buffer_dmasync_sg);
EXPORT_SYMBOL (usb_buffer_unmap_sg);

MODULE_LICENSE("GPL");