message.c

ReactOs中的USB驱动

/*
 * message.c - synchronous message handling
 */
#if 0
#include <linux/pci.h>	/* for scatterlist macros */
#include <linux/usb.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <asm/byteorder.h>
#else
#include "../miniport/usb_wrapper.h"
#endif

#include "hcd.h"	/* for usbcore internals */

// ReactOS specific: No WAITQUEUEs here
#undef wake_up
#define wake_up(a) do {} while(0)

struct usb_api_data {
	wait_queue_head_t wqh;
	int done;
};

static void usb_api_blocking_completion(struct urb *urb, struct pt_regs *regs)
{
	struct usb_api_data *awd = (struct usb_api_data *)urb->context;

	awd->done = 1;
	wmb();
	wake_up(&awd->wqh);
}

// Starts urb and waits for completion or timeout
static int usb_start_wait_urb(struct urb *urb, int timeout, int* actual_length)
{ 
	//DECLARE_WAITQUEUE(wait, current); // Fireball, 24Jan05 - silent gcc complaining about unused wait variable
	struct usb_api_data awd;
	int status;

	//printk("usb_start_wait_urb(): urb devnum=%d, timeout=%d, urb->actual_length=%d\n", urb->dev->devnum, timeout, urb->actual_length);

	init_waitqueue_head((PKEVENT)&awd.wqh); 	
	awd.done = 0;

	set_current_state(TASK_UNINTERRUPTIBLE);
	add_wait_queue(&awd.wqh, &wait);

	urb->context = &awd;
	status = usb_submit_urb(urb, GFP_ATOMIC);

	if (status) {
		// something went wrong
		usb_free_urb(urb);
		set_current_state(TASK_RUNNING);
		remove_wait_queue(&awd.wqh, &wait);
		return status;
	}
	//printk("TRACE 3.1, timeout=%d, awd.done=%d\n", timeout, awd.done);
	while (timeout && !awd.done)
	{		
		timeout = schedule_timeout(timeout);
		set_current_state(TASK_UNINTERRUPTIBLE);
		rmb();
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&awd.wqh, &wait);

	if (!timeout && !awd.done) {
		if (urb->status != -EINPROGRESS) {	/* No callback?!! */
			printk(KERN_ERR "usb: raced timeout, "
			    "pipe 0x%x status %d time left %d\n",
			    urb->pipe, urb->status, timeout);
			status = urb->status;
		} else {
			warn("usb_control/bulk_msg: timeout");
			usb_unlink_urb(urb);  // remove urb safely
			status = -ETIMEDOUT;
		}
	} else
		status = urb->status;

	if (actual_length)
		*actual_length = urb->actual_length;

	usb_free_urb(urb);

  	return status;
}

/*-------------------------------------------------------------------*/
// returns status (negative) or length (positive)
int usb_internal_control_msg(struct usb_device *usb_dev, unsigned int pipe, 
			    struct usb_ctrlrequest *cmd,  void *data, int len, int timeout)
{
	struct urb *urb;
	int retv;
	int length;

	urb = usb_alloc_urb(0, GFP_NOIO);
	if (!urb)
		return -ENOMEM;
  
	usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char*)cmd, data, len,
		   usb_api_blocking_completion, 0);

	retv = usb_start_wait_urb(urb, timeout, &length);

	if (retv < 0)
		return retv;
	else
		return length;
}

/**
 *	usb_control_msg - Builds a control urb, sends it off and waits for completion
 *	@dev: pointer to the usb device to send the message to
 *	@pipe: endpoint "pipe" to send the message to
 *	@request: USB message request value
 *	@requesttype: USB message request type value
 *	@value: USB message value
 *	@index: USB message index value
 *	@data: pointer to the data to send
 *	@size: length in bytes of the data to send
 *	@timeout: time in jiffies to wait for the message to complete before
 *		timing out (if 0 the wait is forever)
 *	Context: !in_interrupt ()
 *
 *	This function sends a simple control message to a specified endpoint
 *	and waits for the message to complete, or timeout.
 *	
 *	If successful, it returns the number of bytes transferred, otherwise a negative error number.
 *
 *	Don't use this function from within an interrupt context, like a
 *	bottom half handler.  If you need an asynchronous message, or need to send
 *	a message from within interrupt context, use usb_submit_urb()
 *      If a thread in your driver uses this call, make sure your disconnect()
 *      method can wait for it to complete.  Since you don't have a handle on
 *      the URB used, you can't cancel the request.
 */
int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u8 requesttype,
			 __u16 value, __u16 index, void *data, __u16 size, int timeout)
{
	struct usb_ctrlrequest *dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
	int ret;
	
	if (!dr)
		return -ENOMEM;

	dr->bRequestType= requesttype;
	dr->bRequest = request;
	dr->wValue = cpu_to_le16p(&value);
	dr->wIndex = cpu_to_le16p(&index);
	dr->wLength = cpu_to_le16p(&size);

	//printk("usb_control_msg: devnum=%d, size=%d, timeout=%d\n", dev->devnum, size, timeout);

	ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
	kfree(dr);
	return ret;
}


/**
 *	usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
 *	@usb_dev: pointer to the usb device to send the message to
 *	@pipe: endpoint "pipe" to send the message to
 *	@data: pointer to the data to send
 *	@len: length in bytes of the data to send
 *	@actual_length: pointer to a location to put the actual length transferred in bytes
 *	@timeout: time in jiffies to wait for the message to complete before
 *		timing out (if 0 the wait is forever)
 *	Context: !in_interrupt ()
 *
 *	This function sends a simple bulk message to a specified endpoint
 *	and waits for the message to complete, or timeout.
 *	
 *	If successful, it returns 0, otherwise a negative error number.
 *	The number of actual bytes transferred will be stored in the 
 *	actual_length paramater.
 *
 *	Don't use this function from within an interrupt context, like a
 *	bottom half handler.  If you need an asynchronous message, or need to
 *	send a message from within interrupt context, use usb_submit_urb()
 *      If a thread in your driver uses this call, make sure your disconnect()
 *      method can wait for it to complete.  Since you don't have a handle on
 *      the URB used, you can't cancel the request.
 */
int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, 
			void *data, int len, int *actual_length, int timeout)
{
	struct urb *urb;

	if (len < 0)
		return -EINVAL;

	urb=usb_alloc_urb(0, GFP_KERNEL);
	if (!urb)
		return -ENOMEM;

	usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
		    usb_api_blocking_completion, 0);

	return usb_start_wait_urb(urb,timeout,actual_length);
}

/*-------------------------------------------------------------------*/
//#warning "Scatter-gather stuff disabled"
#if 0
static void sg_clean (struct usb_sg_request *io)
{
	if (io->urbs) {
		while (io->entries--)
			usb_free_urb (io->urbs [io->entries]);
		kfree (io->urbs);
		io->urbs = 0;
	}
	if (io->dev->dev.dma_mask != 0)
		usb_buffer_unmap_sg (io->dev, io->pipe, io->sg, io->nents);
	io->dev = 0;
}

static void sg_complete (struct urb *urb, struct pt_regs *regs)
{
	struct usb_sg_request	*io = (struct usb_sg_request *) urb->context;
	unsigned long		flags;

	spin_lock_irqsave (&io->lock, flags);

	/* In 2.5 we require hcds' endpoint queues not to progress after fault
	 * reports, until the completion callback (this!) returns.  That lets
	 * device driver code (like this routine) unlink queued urbs first,
	 * if it needs to, since the HC won't work on them at all.  So it's
	 * not possible for page N+1 to overwrite page N, and so on.
	 *
	 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
	 * complete before the HCD can get requests away from hardware,
	 * though never during cleanup after a hard fault.
	 */
	if (io->status
			&& (io->status != -ECONNRESET
				|| urb->status != -ECONNRESET)
			&& urb->actual_length) {
		dev_err (io->dev->bus->controller,
			"dev %s ep%d%s scatterlist error %d/%d\n",
			io->dev->devpath,
			usb_pipeendpoint (urb->pipe),
			usb_pipein (urb->pipe) ? "in" : "out",
			urb->status, io->status);
		// BUG ();
	}

	if (urb->status && urb->status != -ECONNRESET) {
		int		i, found, status;

		io->status = urb->status;

		/* the previous urbs, and this one, completed already.
		 * unlink the later ones so they won't rx/tx bad data,
		 *
		 * FIXME don't bother unlinking urbs that haven't yet been
		 * submitted; those non-error cases shouldn't be syslogged
		 */
		for (i = 0, found = 0; i < io->entries; i++) {
			if (found) {
				status = usb_unlink_urb (io->urbs [i]);
				if (status && status != -EINPROGRESS)
					err ("sg_complete, unlink --> %d",
							status);
			} else if (urb == io->urbs [i])
				found = 1;
		}
	}

	/* on the last completion, signal usb_sg_wait() */
	io->bytes += urb->actual_length;
	io->count--;
	if (!io->count)
		complete (&io->complete);

	spin_unlock_irqrestore (&io->lock, flags);
}


/**
 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
 * @io: request block being initialized.  until usb_sg_wait() returns,
 *	treat this as a pointer to an opaque block of memory,
 * @dev: the usb device that will send or receive the data
 * @pipe: endpoint "pipe" used to transfer the data
 * @period: polling rate for interrupt endpoints, in frames or
 * 	(for high speed endpoints) microframes; ignored for bulk
 * @sg: scatterlist entries
 * @nents: how many entries in the scatterlist
 * @length: how many bytes to send from the scatterlist, or zero to
 * 	send every byte identified in the list.
 * @mem_flags: SLAB_* flags affecting memory allocations in this call
 *
 * Returns zero for success, else a negative errno value.  This initializes a
 * scatter/gather request, allocating resources such as I/O mappings and urb
 * memory (except maybe memory used by USB controller drivers).
 *
 * The request must be issued using usb_sg_wait(), which waits for the I/O to
 * complete (or to be canceled) and then cleans up all resources allocated by
 * usb_sg_init().
 *
 * The request may be canceled with usb_sg_cancel(), either before or after
 * usb_sg_wait() is called.
 */
int usb_sg_init (
	struct usb_sg_request	*io,
	struct usb_device	*dev,
	unsigned		pipe, 
	unsigned		period,
	struct scatterlist	*sg,
	int			nents,
	size_t			length,
	int			mem_flags
)
{
	int			i;
	int			urb_flags;
	int			dma;

	if (!io || !dev || !sg
			|| usb_pipecontrol (pipe)
			|| usb_pipeisoc (pipe)
			|| nents <= 0)
		return -EINVAL;

	spin_lock_init (&io->lock);
	io->dev = dev;
	io->pipe = pipe;
	io->sg = sg;
	io->nents = nents;

	/* not all host controllers use DMA (like the mainstream pci ones);
	 * they can use PIO (sl811) or be software over another transport.
	 */
	dma = (dev->dev.dma_mask != 0);
	if (dma)
		io->entries = usb_buffer_map_sg (dev, pipe, sg, nents);
	else
		io->entries = nents;

	/* initialize all the urbs we'll use */
	if (io->entries <= 0)
		return io->entries;

	io->count = 0;
	io->urbs = kmalloc (io->entries * sizeof *io->urbs, mem_flags);