auerswald.c

linux-2.6.15.6

        newbp->len = bp->len;

        /* insert new buffer in read list */
        spin_lock_irqsave (&ccp->bufctl.lock, flags);
	list_add_tail (&newbp->buff_list, &ccp->bufctl.rec_buff_list);
        spin_unlock_irqrestore (&ccp->bufctl.lock, flags);
        dbg ("read buffer appended to rec_list");

        /* wake up pending synchronous reads */
	wake_up (&ccp->readwait);
}


/* Delete an auerswald driver context */
static void auerswald_delete( pauerswald_t cp)
{
	dbg( "auerswald_delete");
	if (cp == NULL)
		return;

	/* Wake up all processes waiting for a buffer */
	wake_up (&cp->bufferwait);

	/* Cleaning up */
	auerswald_int_release (cp);
	auerchain_free (&cp->controlchain);
	auerbuf_free_buffers (&cp->bufctl);

	/* release the memory */
	kfree( cp);
}


/* Delete an auerswald character context */
static void auerchar_delete( pauerchar_t ccp)
{
	dbg ("auerchar_delete");
	if (ccp == NULL)
		return;

        /* wake up pending synchronous reads */
	ccp->removed = 1;
	wake_up (&ccp->readwait);

	/* remove the read buffer */
	if (ccp->readbuf) {
		auerbuf_releasebuf (ccp->readbuf);
		ccp->readbuf = NULL;
	}

	/* remove the character buffers */
	auerbuf_free_buffers (&ccp->bufctl);

	/* release the memory */
	kfree( ccp);
}


/* add a new service to the device
   scp->id must be set!
   return: 0 if OK, else error code
*/
static int auerswald_addservice (pauerswald_t cp, pauerscon_t scp)
{
	int ret;

	/* is the device available? */
	if (!cp->usbdev) {
		dbg ("usbdev == NULL");
		return -EIO;	/*no: can not add a service, sorry*/
	}

	/* is the service available? */
	if (cp->services[scp->id]) {
		dbg ("service is busy");
                return -EBUSY;
	}

	/* device is available, service is free */
	cp->services[scp->id] = scp;

	/* register service in device */
	ret = auerchain_control_msg(
		&cp->controlchain,                      /* pointer to control chain */
		cp->usbdev,                             /* pointer to device */
		usb_sndctrlpipe (cp->usbdev, 0),        /* pipe to control endpoint */
		AUV_CHANNELCTL,                         /* USB message request value */
		AUT_WREQ,                               /* USB message request type value */
		0x01,              /* open                 USB message value */
		scp->id,            		        /* USB message index value */
		NULL,                                   /* pointer to the data to send */
		0,                                      /* length in bytes of the data to send */
		HZ * 2);                                /* time to wait for the message to complete before timing out */
	if (ret < 0) {
		dbg ("auerswald_addservice: auerchain_control_msg returned error code %d", ret);
		/* undo above actions */
		cp->services[scp->id] = NULL;
		return ret;
	}

	dbg ("auerswald_addservice: channel open OK");
	return 0;
}


/* remove a service from the the device
   scp->id must be set! */
static void auerswald_removeservice (pauerswald_t cp, pauerscon_t scp)
{
	dbg ("auerswald_removeservice called");

	/* check if we have a service allocated */
	if (scp->id == AUH_UNASSIGNED)
		return;

	/* If there is a device: close the channel */
	if (cp->usbdev) {
		/* Close the service channel inside the device */
		int ret = auerchain_control_msg(
		&cp->controlchain,            		/* pointer to control chain */
		cp->usbdev,         		        /* pointer to device */
		usb_sndctrlpipe (cp->usbdev, 0),	/* pipe to control endpoint */
		AUV_CHANNELCTL,                         /* USB message request value */
		AUT_WREQ,                               /* USB message request type value */
		0x00,              // close             /* USB message value */
		scp->id,            		        /* USB message index value */
		NULL,                                   /* pointer to the data to send */
		0,                                      /* length in bytes of the data to send */
		HZ * 2);                                /* time to wait for the message to complete before timing out */
		if (ret < 0) {
			dbg ("auerswald_removeservice: auerchain_control_msg returned error code %d", ret);
		}
		else {
			dbg ("auerswald_removeservice: channel close OK");
		}
	}

	/* remove the service from the device */
	cp->services[scp->id] = NULL;
	scp->id = AUH_UNASSIGNED;
}


/* --------------------------------------------------------------------- */
/* Char device functions                                                 */

/* Open a new character device */
static int auerchar_open (struct inode *inode, struct file *file)
{
	int dtindex = iminor(inode);
	pauerswald_t cp = NULL;
	pauerchar_t ccp = NULL;
	struct usb_interface *intf;
        int ret;

        /* minor number in range? */
	if (dtindex < 0) {
		return -ENODEV;
        }
	intf = usb_find_interface(&auerswald_driver, dtindex);
	if (!intf) {
		return -ENODEV;
	}

	/* usb device available? */
	cp = usb_get_intfdata (intf);
	if (cp == NULL) {
		return -ENODEV;
	}
	if (down_interruptible (&cp->mutex)) {
		return -ERESTARTSYS;
	}

	/* we have access to the device. Now lets allocate memory */
	ccp = (pauerchar_t) kmalloc(sizeof(auerchar_t), GFP_KERNEL);
	if (ccp == NULL) {
		err ("out of memory");
		ret = -ENOMEM;
		goto ofail;
	}

	/* Initialize device descriptor */
	memset( ccp, 0, sizeof(auerchar_t));
	init_MUTEX( &ccp->mutex);
	init_MUTEX( &ccp->readmutex);
        auerbuf_init (&ccp->bufctl);
        ccp->scontext.id = AUH_UNASSIGNED;
        ccp->scontext.dispatch = auerchar_ctrlread_dispatch;
	ccp->scontext.disconnect = auerchar_disconnect;
	init_waitqueue_head (&ccp->readwait);

	ret = auerbuf_setup (&ccp->bufctl, AU_RBUFFERS, cp->maxControlLength+AUH_SIZE);
       	if (ret) {
		goto ofail;
	}

	cp->open_count++;
	ccp->auerdev = cp;
	dbg("open %s as /dev/%s", cp->dev_desc, cp->name);
	up (&cp->mutex);

	/* file IO stuff */
	file->f_pos = 0;
	file->private_data = ccp;
	return nonseekable_open(inode, file);

	/* Error exit */
ofail:	up (&cp->mutex);
	auerchar_delete (ccp);
	return ret;
}


/* IOCTL functions */
static int auerchar_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	pauerchar_t ccp = (pauerchar_t) file->private_data;
	int ret = 0;
        audevinfo_t devinfo;
        pauerswald_t cp = NULL;
	unsigned int u;
	unsigned int __user *user_arg = (unsigned int __user *)arg;

        dbg ("ioctl");

	/* get the mutexes */
	if (down_interruptible (&ccp->mutex)) {
		return -ERESTARTSYS;
	}
	cp = ccp->auerdev;
	if (!cp) {
		up (&ccp->mutex);
                return -ENODEV;
	}
	if (down_interruptible (&cp->mutex)) {
		up(&ccp->mutex);
		return -ERESTARTSYS;
	}

	/* Check for removal */
	if (!cp->usbdev) {
		up(&cp->mutex);
		up(&ccp->mutex);
                return -ENODEV;
	}

	switch (cmd) {

	/* return != 0 if Transmitt channel ready to send */
	case IOCTL_AU_TXREADY:
		dbg ("IOCTL_AU_TXREADY");
		u   = ccp->auerdev
		   && (ccp->scontext.id != AUH_UNASSIGNED)
		   && !list_empty (&cp->bufctl.free_buff_list);
	        ret = put_user (u, user_arg);
		break;

	/* return != 0 if connected to a service channel */
	case IOCTL_AU_CONNECT:
		dbg ("IOCTL_AU_CONNECT");
		u = (ccp->scontext.id != AUH_UNASSIGNED);
	        ret = put_user (u, user_arg);
		break;

	/* return != 0 if Receive Data available */
	case IOCTL_AU_RXAVAIL:
		dbg ("IOCTL_AU_RXAVAIL");
		if (ccp->scontext.id == AUH_UNASSIGNED) {
                        ret = -EIO;
                        break;
                }
		u = 0;	/* no data */
		if (ccp->readbuf) {
			int restlen = ccp->readbuf->len - ccp->readoffset;
			if (restlen > 0)
				u = 1;
		}
		if (!u) {
        		if (!list_empty (&ccp->bufctl.rec_buff_list)) {
				u = 1;
			}
		}
	        ret = put_user (u, user_arg);
		break;

	/* return the max. buffer length for the device */
	case IOCTL_AU_BUFLEN:
		dbg ("IOCTL_AU_BUFLEN");
		u = cp->maxControlLength;
	        ret = put_user (u, user_arg);
		break;

	/* requesting a service channel */
        case IOCTL_AU_SERVREQ:
		dbg ("IOCTL_AU_SERVREQ");
                /* requesting a service means: release the previous one first */
		auerswald_removeservice (cp, &ccp->scontext);
		/* get the channel number */
		ret = get_user (u, user_arg);
		if (ret) {
			break;
		}
		if ((u < AUH_FIRSTUSERCH) || (u >= AUH_TYPESIZE)) {
                        ret = -EIO;
                        break;
                }
                dbg ("auerchar service request parameters are ok");
		ccp->scontext.id = u;

		/* request the service now */
		ret = auerswald_addservice (cp, &ccp->scontext);
		if (ret) {
			/* no: revert service entry */
                	ccp->scontext.id = AUH_UNASSIGNED;
		}
		break;

	/* get a string descriptor for the device */
	case IOCTL_AU_DEVINFO:
		dbg ("IOCTL_AU_DEVINFO");
                if (copy_from_user (&devinfo, (void __user *) arg, sizeof (audevinfo_t))) {
        		ret = -EFAULT;
	        	break;
                }
		u = strlen(cp->dev_desc)+1;
		if (u > devinfo.bsize) {
			u = devinfo.bsize;
		}
		ret = copy_to_user(devinfo.buf, cp->dev_desc, u) ? -EFAULT : 0;
		break;

	/* get the max. string descriptor length */
        case IOCTL_AU_SLEN:
		dbg ("IOCTL_AU_SLEN");
		u = AUSI_DLEN;
	        ret = put_user (u, user_arg);
		break;

	default:
		dbg ("IOCTL_AU_UNKNOWN");
		ret = -ENOIOCTLCMD;
		break;
        }
	/* release the mutexes */
	up(&cp->mutex);
	up(&ccp->mutex);
	return ret;
}

/* Read data from the device */
static ssize_t auerchar_read (struct file *file, char __user *buf, size_t count, loff_t * ppos)
{
        unsigned long flags;
	pauerchar_t ccp = (pauerchar_t) file->private_data;
        pauerbuf_t   bp = NULL;
	wait_queue_t wait;

        dbg ("auerchar_read");

	/* Error checking */
	if (!ccp)
		return -EIO;
	if (*ppos)
 		return -ESPIPE;
        if (count == 0)
		return 0;

	/* get the mutex */
	if (down_interruptible (&ccp->mutex))
		return -ERESTARTSYS;

	/* Can we expect to read something? */
	if (ccp->scontext.id == AUH_UNASSIGNED) {
		up (&ccp->mutex);
                return -EIO;
	}

	/* only one reader per device allowed */
	if (down_interruptible (&ccp->readmutex)) {
		up (&ccp->mutex);
		return -ERESTARTSYS;
	}

	/* read data from readbuf, if available */
doreadbuf:
	bp = ccp->readbuf;
	if (bp) {
		/* read the maximum bytes */
		int restlen = bp->len - ccp->readoffset;
		if (restlen < 0)
			restlen = 0;
		if (count > restlen)
			count = restlen;
		if (count) {
			if (copy_to_user (buf, bp->bufp+ccp->readoffset, count)) {
				dbg ("auerswald_read: copy_to_user failed");
				up (&ccp->readmutex);
				up (&ccp->mutex);
				return -EFAULT;
			}
		}
		/* advance the read offset */
		ccp->readoffset += count;