iowarrior.c

linux 内核源代码

	usb_free_urb(int_out_urb);
error_no_urb:
	atomic_dec(&dev->write_busy);
	wake_up_interruptible(&dev->write_wait);
exit:
	mutex_unlock(&dev->mutex);
	return retval;
}

/**
 *	iowarrior_ioctl
 */
static int iowarrior_ioctl(struct inode *inode, struct file *file,
			   unsigned int cmd, unsigned long arg)
{
	struct iowarrior *dev = NULL;
	__u8 *buffer;
	__u8 __user *user_buffer;
	int retval;
	int io_res;		/* checks for bytes read/written and copy_to/from_user results */

	dev = (struct iowarrior *)file->private_data;
	if (dev == NULL) {
		return -ENODEV;
	}

	buffer = kzalloc(dev->report_size, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	/* lock this object */
	mutex_lock(&dev->mutex);

	/* verify that the device wasn't unplugged */
	if (!dev->present) {
		retval = -ENODEV;
		goto error_out;
	}

	dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __func__, dev->minor, cmd,
	    arg);

	retval = 0;
	io_res = 0;
	switch (cmd) {
	case IOW_WRITE:
		if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
			user_buffer = (__u8 __user *)arg;
			io_res = copy_from_user(buffer, user_buffer,
						dev->report_size);
			if (io_res) {
				retval = -EFAULT;
			} else {
				io_res = usb_set_report(dev->interface, 2, 0,
							buffer,
							dev->report_size);
				if (io_res < 0)
					retval = io_res;
			}
		} else {
			retval = -EINVAL;
			dev_err(&dev->interface->dev,
				"ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
				dev->product_id);
		}
		break;
	case IOW_READ:
		user_buffer = (__u8 __user *)arg;
		io_res = usb_get_report(dev->udev,
					dev->interface->cur_altsetting, 1, 0,
					buffer, dev->report_size);
		if (io_res < 0)
			retval = io_res;
		else {
			io_res = copy_to_user(user_buffer, buffer, dev->report_size);
			if (io_res < 0)
				retval = -EFAULT;
		}
		break;
	case IOW_GETINFO:
		{
			/* Report available information for the device */
			struct iowarrior_info info;
			/* needed for power consumption */
			struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;

			/* directly from the descriptor */
			info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
			info.product = dev->product_id;
			info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);

			/* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
			info.speed = le16_to_cpu(dev->udev->speed);
			info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
			info.report_size = dev->report_size;

			/* serial number string has been read earlier 8 chars or empty string */
			memcpy(info.serial, dev->chip_serial,
			       sizeof(dev->chip_serial));
			if (cfg_descriptor == NULL) {
				info.power = -1;	/* no information available */
			} else {
				/* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
				info.power = cfg_descriptor->bMaxPower * 2;
			}
			io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
					 sizeof(struct iowarrior_info));
			if (io_res < 0)
				retval = -EFAULT;
			break;
		}
	default:
		/* return that we did not understand this ioctl call */
		retval = -ENOTTY;
		break;
	}
error_out:
	/* unlock the device */
	mutex_unlock(&dev->mutex);
	kfree(buffer);
	return retval;
}

/**
 *	iowarrior_open
 */
static int iowarrior_open(struct inode *inode, struct file *file)
{
	struct iowarrior *dev = NULL;
	struct usb_interface *interface;
	int subminor;
	int retval = 0;

	dbg("%s", __func__);

	subminor = iminor(inode);

	interface = usb_find_interface(&iowarrior_driver, subminor);
	if (!interface) {
		err("%s - error, can't find device for minor %d", __FUNCTION__,
		    subminor);
		return -ENODEV;
	}

	mutex_lock(&iowarrior_open_disc_lock);
	dev = usb_get_intfdata(interface);
	if (!dev) {
		mutex_unlock(&iowarrior_open_disc_lock);
		return -ENODEV;
	}

	mutex_lock(&dev->mutex);
	mutex_unlock(&iowarrior_open_disc_lock);

	/* Only one process can open each device, no sharing. */
	if (dev->opened) {
		retval = -EBUSY;
		goto out;
	}

	/* setup interrupt handler for receiving values */
	if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
		dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
		retval = -EFAULT;
		goto out;
	}
	/* increment our usage count for the driver */
	++dev->opened;
	/* save our object in the file's private structure */
	file->private_data = dev;
	retval = 0;

out:
	mutex_unlock(&dev->mutex);
	return retval;
}

/**
 *	iowarrior_release
 */
static int iowarrior_release(struct inode *inode, struct file *file)
{
	struct iowarrior *dev;
	int retval = 0;

	dev = (struct iowarrior *)file->private_data;
	if (dev == NULL) {
		return -ENODEV;
	}

	dbg("%s - minor %d", __func__, dev->minor);

	/* lock our device */
	mutex_lock(&dev->mutex);

	if (dev->opened <= 0) {
		retval = -ENODEV;	/* close called more than once */
		mutex_unlock(&dev->mutex);
	} else {
		dev->opened = 0;	/* we're closeing now */
		retval = 0;
		if (dev->present) {
			/*
			   The device is still connected so we only shutdown
			   pending read-/write-ops.
			 */
			usb_kill_urb(dev->int_in_urb);
			wake_up_interruptible(&dev->read_wait);
			wake_up_interruptible(&dev->write_wait);
			mutex_unlock(&dev->mutex);
		} else {
			/* The device was unplugged, cleanup resources */
			mutex_unlock(&dev->mutex);
			iowarrior_delete(dev);
		}
	}
	return retval;
}

static unsigned iowarrior_poll(struct file *file, poll_table * wait)
{
	struct iowarrior *dev = file->private_data;
	unsigned int mask = 0;

	if (!dev->present)
		return POLLERR | POLLHUP;

	poll_wait(file, &dev->read_wait, wait);
	poll_wait(file, &dev->write_wait, wait);

	if (!dev->present)
		return POLLERR | POLLHUP;

	if (read_index(dev) != -1)
		mask |= POLLIN | POLLRDNORM;

	if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
		mask |= POLLOUT | POLLWRNORM;
	return mask;
}

/*
 * File operations needed when we register this driver.
 * This assumes that this driver NEEDS file operations,
 * of course, which means that the driver is expected
 * to have a node in the /dev directory. If the USB
 * device were for a network interface then the driver
 * would use "struct net_driver" instead, and a serial
 * device would use "struct tty_driver".
 */
static struct file_operations iowarrior_fops = {
	.owner = THIS_MODULE,
	.write = iowarrior_write,
	.read = iowarrior_read,
	.ioctl = iowarrior_ioctl,
	.open = iowarrior_open,
	.release = iowarrior_release,
	.poll = iowarrior_poll,
};

/*
 * usb class driver info in order to get a minor number from the usb core,
 * and to have the device registered with devfs and the driver core
 */
static struct usb_class_driver iowarrior_class = {
	.name = "iowarrior%d",
	.fops = &iowarrior_fops,
	.minor_base = IOWARRIOR_MINOR_BASE,
};

/*---------------------------------*/
/*  probe and disconnect functions */
/*---------------------------------*/
/**
 *	iowarrior_probe
 *
 *	Called by the usb core when a new device is connected that it thinks
 *	this driver might be interested in.
 */
static int iowarrior_probe(struct usb_interface *interface,
			   const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(interface);
	struct iowarrior *dev = NULL;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	int i;
	int retval = -ENOMEM;

	/* allocate memory for our device state and intialize it */
	dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
	if (dev == NULL) {
		dev_err(&interface->dev, "Out of memory\n");
		return retval;
	}

	mutex_init(&dev->mutex);

	atomic_set(&dev->intr_idx, 0);
	atomic_set(&dev->read_idx, 0);
	spin_lock_init(&dev->intr_idx_lock);
	atomic_set(&dev->overflow_flag, 0);
	init_waitqueue_head(&dev->read_wait);
	atomic_set(&dev->write_busy, 0);
	init_waitqueue_head(&dev->write_wait);

	dev->udev = udev;
	dev->interface = interface;

	iface_desc = interface->cur_altsetting;
	dev->product_id = le16_to_cpu(udev->descriptor.idProduct);

	/* set up the endpoint information */
	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
		endpoint = &iface_desc->endpoint[i].desc;

		if (usb_endpoint_is_int_in(endpoint))
			dev->int_in_endpoint = endpoint;
		if (usb_endpoint_is_int_out(endpoint))
			/* this one will match for the IOWarrior56 only */
			dev->int_out_endpoint = endpoint;
	}
	/* we have to check the report_size often, so remember it in the endianess suitable for our machine */
	dev->report_size = le16_to_cpu(dev->int_in_endpoint->wMaxPacketSize);
	if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
		/* IOWarrior56 has wMaxPacketSize different from report size */
		dev->report_size = 7;

	/* create the urb and buffer for reading */
	dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->int_in_urb) {
		dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
		goto error;
	}
	dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
	if (!dev->int_in_buffer) {
		dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
		goto error;
	}
	usb_fill_int_urb(dev->int_in_urb, dev->udev,
			 usb_rcvintpipe(dev->udev,
					dev->int_in_endpoint->bEndpointAddress),
			 dev->int_in_buffer, dev->report_size,
			 iowarrior_callback, dev,
			 dev->int_in_endpoint->bInterval);
	/* create an internal buffer for interrupt data from the device */
	dev->read_queue =
	    kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
		    GFP_KERNEL);
	if (!dev->read_queue) {
		dev_err(&interface->dev, "Couldn't allocate read_queue\n");
		goto error;
	}
	/* Get the serial-number of the chip */
	memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
	usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
		   sizeof(dev->chip_serial));
	if (strlen(dev->chip_serial) != 8)
		memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));

	/* Set the idle timeout to 0, if this is interface 0 */
	if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
	    usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			    0x0A,
			    USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
			    0, NULL, 0, USB_CTRL_SET_TIMEOUT);
	}
	/* allow device read and ioctl */
	dev->present = 1;

	/* we can register the device now, as it is ready */
	usb_set_intfdata(interface, dev);

	retval = usb_register_dev(interface, &iowarrior_class);
	if (retval) {
		/* something prevented us from registering this driver */
		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
		usb_set_intfdata(interface, NULL);
		goto error;
	}

	dev->minor = interface->minor;

	/* let the user know what node this device is now attached to */
	dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
		 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
		 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
	return retval;

error:
	iowarrior_delete(dev);
	return retval;
}

/**
 *	iowarrior_disconnect
 *
 *	Called by the usb core when the device is removed from the system.
 */
static void iowarrior_disconnect(struct usb_interface *interface)
{
	struct iowarrior *dev;
	int minor;

	dev = usb_get_intfdata(interface);
	mutex_lock(&iowarrior_open_disc_lock);
	usb_set_intfdata(interface, NULL);

	minor = dev->minor;

	/* give back our minor */
	usb_deregister_dev(interface, &iowarrior_class);

	mutex_lock(&dev->mutex);

	/* prevent device read, write and ioctl */
	dev->present = 0;

	mutex_unlock(&dev->mutex);
	mutex_unlock(&iowarrior_open_disc_lock);

	if (dev->opened) {
		/* There is a process that holds a filedescriptor to the device ,
		   so we only shutdown read-/write-ops going on.
		   Deleting the device is postponed until close() was called.
		 */
		usb_kill_urb(dev->int_in_urb);
		wake_up_interruptible(&dev->read_wait);
		wake_up_interruptible(&dev->write_wait);
	} else {
		/* no process is using the device, cleanup now */
		iowarrior_delete(dev);
	}

	dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
		 minor - IOWARRIOR_MINOR_BASE);
}

/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver iowarrior_driver = {
	.name = "iowarrior",
	.probe = iowarrior_probe,
	.disconnect = iowarrior_disconnect,
	.id_table = iowarrior_ids,
};

static int __init iowarrior_init(void)
{
	return usb_register(&iowarrior_driver);
}

static void __exit iowarrior_exit(void)
{
	usb_deregister(&iowarrior_driver);
}

module_init(iowarrior_init);
module_exit(iowarrior_exit);