cdc-acm.c

linux qt class 类的函数定义

	struct acm *acm = tty->driver_data;
	if (!ACM_READY(acm)) return -EINVAL;
	return acm->writeurb->status == -EINPROGRESS ? 0 : acm->writesize;
}

static int acm_tty_chars_in_buffer(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	if (!ACM_READY(acm)) return -EINVAL;
	return acm->writeurb->status == -EINPROGRESS ? acm->writeurb->transfer_buffer_length : 0;
}

static void acm_tty_throttle(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	if (!ACM_READY(acm)) return;
	acm->throttle = 1;
}

static void acm_tty_unthrottle(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	if (!ACM_READY(acm)) return;
	acm->throttle = 0;
	if (acm->readurb->status != -EINPROGRESS)
		acm_read_bulk(acm->readurb);
}

static void acm_tty_break_ctl(struct tty_struct *tty, int state)
{
	struct acm *acm = tty->driver_data;
	if (!ACM_READY(acm)) return;
	if (acm_send_break(acm, state ? 0xffff : 0))
		dbg("send break failed");
}

static int acm_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct acm *acm = tty->driver_data;
	unsigned int mask, newctrl;

	if (!ACM_READY(acm)) return -EINVAL;

	switch (cmd) {

		case TIOCMGET:

			return put_user((acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
				(acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
				(acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
				(acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
				(acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
				 TIOCM_CTS, (unsigned long *) arg);

		case TIOCMSET:
		case TIOCMBIS:
		case TIOCMBIC:

			if (get_user(mask, (unsigned long *) arg))
				return -EFAULT;

			newctrl = acm->ctrlout;
			mask = (mask & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (mask & TIOCM_RTS ? ACM_CTRL_RTS : 0);

			switch (cmd) {
				case TIOCMSET: newctrl  =  mask; break;
				case TIOCMBIS: newctrl |=  mask; break;
				case TIOCMBIC: newctrl &= ~mask; break;
			}

			if (acm->ctrlout == newctrl) return 0;
			return acm_set_control(acm, acm->ctrlout = newctrl);
	}

	return -ENOIOCTLCMD;
}

static __u32 acm_tty_speed[] = {
	0, 50, 75, 110, 134, 150, 200, 300, 600,
	1200, 1800, 2400, 4800, 9600, 19200, 38400,
	57600, 115200, 230400, 460800, 500000, 576000,
	921600, 1000000, 1152000, 1500000, 2000000,
	2500000, 3000000, 3500000, 4000000
};

static __u8 acm_tty_size[] = {
	5, 6, 7, 8
};

static void acm_tty_set_termios(struct tty_struct *tty, struct termios *termios_old)
{
	struct acm *acm = tty->driver_data;
	struct termios *termios = tty->termios;
	struct acm_line newline;
	int newctrl = acm->ctrlout;

	if (!ACM_READY(acm)) return;

	newline.speed = cpu_to_le32p(acm_tty_speed +
		(termios->c_cflag & CBAUD & ~CBAUDEX) + (termios->c_cflag & CBAUDEX ? 15 : 0));
	newline.stopbits = termios->c_cflag & CSTOPB ? 2 : 0;
	newline.parity = termios->c_cflag & PARENB ?
		(termios->c_cflag & PARODD ? 1 : 2) + (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
	newline.databits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];

	acm->clocal = ((termios->c_cflag & CLOCAL) != 0);

	if (!newline.speed) {
		newline.speed = acm->line.speed;
		newctrl &= ~ACM_CTRL_DTR;
	} else  newctrl |=  ACM_CTRL_DTR;

	if (newctrl != acm->ctrlout)
		acm_set_control(acm, acm->ctrlout = newctrl);

	if (memcmp(&acm->line, &newline, sizeof(struct acm_line))) {
		memcpy(&acm->line, &newline, sizeof(struct acm_line));
		dbg("set line: %d %d %d %d", newline.speed, newline.stopbits, newline.parity, newline.databits);
		acm_set_line(acm, &acm->line);
	}
}

/*
 * USB probe and disconnect routines.
 */

static void *acm_probe(struct usb_device *dev, unsigned int ifnum,
		       const struct usb_device_id *id)
{
	struct acm *acm;
	struct usb_config_descriptor *cfacm;
	struct usb_interface_descriptor *ifcom, *ifdata;
	struct usb_endpoint_descriptor *epctrl, *epread, *epwrite;
	int readsize, ctrlsize, minor, i;
	unsigned char *buf;

	for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {

		cfacm = dev->config + i;

		dbg("probing config %d", cfacm->bConfigurationValue);

		if (cfacm->bNumInterfaces != 2 ||
		    usb_interface_claimed(cfacm->interface + 0) ||
		    usb_interface_claimed(cfacm->interface + 1))
			continue;

		ifcom = cfacm->interface[0].altsetting + 0;
		ifdata = cfacm->interface[1].altsetting + 0;

		if (ifdata->bInterfaceClass != 10 || ifdata->bNumEndpoints < 2) {
			ifcom = cfacm->interface[1].altsetting + 0;
			ifdata = cfacm->interface[0].altsetting + 0;
			if (ifdata->bInterfaceClass != 10 || ifdata->bNumEndpoints < 2)
				continue;
		}

		if (ifcom->bInterfaceClass != 2 || ifcom->bInterfaceSubClass != 2 ||
		    ifcom->bInterfaceProtocol != 1 || ifcom->bNumEndpoints < 1)
			continue;

		epctrl = ifcom->endpoint + 0;
		epread = ifdata->endpoint + 0;
		epwrite = ifdata->endpoint + 1;

		if ((epctrl->bEndpointAddress & 0x80) != 0x80 || (epctrl->bmAttributes & 3) != 3 ||
		   (epread->bmAttributes & 3) != 2 || (epwrite->bmAttributes & 3) != 2 ||
		   ((epread->bEndpointAddress & 0x80) ^ (epwrite->bEndpointAddress & 0x80)) != 0x80)
			continue;

		if ((epread->bEndpointAddress & 0x80) != 0x80) {
			epread = ifdata->endpoint + 1;
			epwrite = ifdata->endpoint + 0;
		}

		usb_set_configuration(dev, cfacm->bConfigurationValue);

		for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
		if (acm_table[minor]) {
			err("no more free acm devices");
			return NULL;
		}

		if (!(acm = kmalloc(sizeof(struct acm), GFP_KERNEL))) {
			err("out of memory");
			return NULL;
		}
		memset(acm, 0, sizeof(struct acm));

		ctrlsize = epctrl->wMaxPacketSize;
		readsize = epread->wMaxPacketSize;
		acm->writesize = epwrite->wMaxPacketSize;
		acm->iface = cfacm->interface;
		acm->minor = minor;
		acm->dev = dev;

		acm->tqueue.routine = acm_softint;
		acm->tqueue.data = acm;

		if (!(buf = kmalloc(ctrlsize + readsize + acm->writesize, GFP_KERNEL))) {
			err("out of memory");
			kfree(acm);
			return NULL;
		}

		acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
		if (!acm->ctrlurb) {
			err("out of memory");
			kfree(acm);
			return NULL;
		}
		acm->readurb = usb_alloc_urb(0, GFP_KERNEL);
		if (!acm->readurb) {
			err("out of memory");
			usb_free_urb(acm->ctrlurb);
			kfree(acm);
			return NULL;
		}
		acm->writeurb = usb_alloc_urb(0, GFP_KERNEL);
		if (!acm->writeurb) {
			err("out of memory");
			usb_free_urb(acm->readurb);
			usb_free_urb(acm->ctrlurb);
			kfree(acm);
			return NULL;
		}

		usb_fill_int_urb(acm->ctrlurb, dev, usb_rcvintpipe(dev, epctrl->bEndpointAddress),
			buf, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);

		usb_fill_bulk_urb(acm->readurb, dev, usb_rcvbulkpipe(dev, epread->bEndpointAddress),
			buf += ctrlsize, readsize, acm_read_bulk, acm);
		acm->readurb->transfer_flags |= USB_NO_FSBR;

		usb_fill_bulk_urb(acm->writeurb, dev, usb_sndbulkpipe(dev, epwrite->bEndpointAddress),
			buf += readsize, acm->writesize, acm_write_bulk, acm);
		acm->writeurb->transfer_flags |= USB_NO_FSBR;

		printk(KERN_INFO "ttyACM%d: USB ACM device\n", minor);

		acm_set_control(acm, acm->ctrlout);

		acm->line.speed = cpu_to_le32(9600);
		acm->line.databits = 8;
		acm_set_line(acm, &acm->line);

		usb_driver_claim_interface(&acm_driver, acm->iface + 0, acm);
		usb_driver_claim_interface(&acm_driver, acm->iface + 1, acm);

		tty_register_devfs(&acm_tty_driver, 0, minor);
		return acm_table[minor] = acm;
	}

	return NULL;
}

static void acm_disconnect(struct usb_device *dev, void *ptr)
{
	struct acm *acm = ptr;

	if (!acm || !acm->dev) {
		dbg("disconnect on nonexisting interface");
		return;
	}

	acm->dev = NULL;

	usb_unlink_urb(acm->ctrlurb);
	usb_unlink_urb(acm->readurb);
	usb_unlink_urb(acm->writeurb);

	kfree(acm->ctrlurb->transfer_buffer);

	usb_driver_release_interface(&acm_driver, acm->iface + 0);
	usb_driver_release_interface(&acm_driver, acm->iface + 1);

	if (!acm->used) {
		tty_unregister_devfs(&acm_tty_driver, acm->minor);
		acm_table[acm->minor] = NULL;
		usb_free_urb(acm->ctrlurb);
		usb_free_urb(acm->readurb);
		usb_free_urb(acm->writeurb);
		kfree(acm);
		return;
	}

	if (acm->tty)
		tty_hangup(acm->tty);
}

/*
 * USB driver structure.
 */

static struct usb_device_id acm_ids[] = {
	{ USB_DEVICE_INFO(USB_CLASS_COMM, 0, 0) },
	{ }
};

MODULE_DEVICE_TABLE (usb, acm_ids);

static struct usb_driver acm_driver = {
	name:		"acm",
	probe:		acm_probe,
	disconnect:	acm_disconnect,
	id_table:	acm_ids,
};

/*
 * TTY driver structures.
 */

static int acm_tty_refcount;

static struct tty_struct *acm_tty_table[ACM_TTY_MINORS];
static struct termios *acm_tty_termios[ACM_TTY_MINORS];
static struct termios *acm_tty_termios_locked[ACM_TTY_MINORS];

static struct tty_driver acm_tty_driver = {
	magic:			TTY_DRIVER_MAGIC,
	driver_name:		"acm",
	name:			"usb/acm/%d",
	major:			ACM_TTY_MAJOR,
	minor_start:		0,
	num:			ACM_TTY_MINORS,
	type:			TTY_DRIVER_TYPE_SERIAL,
	subtype:		SERIAL_TYPE_NORMAL,
	flags:			TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,

	refcount:		&acm_tty_refcount,

	table:			acm_tty_table,
	termios:		acm_tty_termios,
	termios_locked:		acm_tty_termios_locked,

	open:			acm_tty_open,
	close:			acm_tty_close,
	write:			acm_tty_write,
	write_room:		acm_tty_write_room,
	ioctl:			acm_tty_ioctl,
	throttle:		acm_tty_throttle,
	unthrottle:		acm_tty_unthrottle,
	chars_in_buffer:	acm_tty_chars_in_buffer,
	break_ctl:		acm_tty_break_ctl,
	set_termios:		acm_tty_set_termios
};

/*
 * Init / exit.
 */

static int __init acm_init(void)
{
	acm_tty_driver.init_termios =		tty_std_termios;
	acm_tty_driver.init_termios.c_cflag =	B9600 | CS8 | CREAD | HUPCL | CLOCAL;

	if (tty_register_driver(&acm_tty_driver))
		return -1;

	if (usb_register(&acm_driver) < 0) {
		tty_unregister_driver(&acm_tty_driver);
		return -1;
	}

	info(DRIVER_VERSION ":" DRIVER_DESC);

	return 0;
}

static void __exit acm_exit(void)
{
	usb_deregister(&acm_driver);
	tty_unregister_driver(&acm_tty_driver);
}

module_init(acm_init);
module_exit(acm_exit);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");