audio.c

Usb1.1驱动c语言源代码

	up(&open_sem);
	wake_up(&open_wait);
	while (!list_empty(&s->audiolist)) {
		as = list_entry(s->audiolist.next, struct usb_audiodev, list);
		list_del(&as->list);
		usbin_release(as);
		usbout_release(as);
		dmabuf_release(&as->usbin.dma);
		dmabuf_release(&as->usbout.dma);
		kfree(as);
	}
	while (!list_empty(&s->mixerlist)) {
		ms = list_entry(s->mixerlist.next, struct usb_mixerdev, list);
		list_del(&ms->list);
		kfree(ms);
	}
	kfree(s);
}

extern inline int prog_dmabuf_in(struct usb_audiodev *as)
{
	usbin_stop(as);
	return dmabuf_init(&as->usbin.dma);
}

extern inline int prog_dmabuf_out(struct usb_audiodev *as)
{
	usbout_stop(as);
	return dmabuf_init(&as->usbout.dma);
}

/* --------------------------------------------------------------------- */

static loff_t usb_audio_llseek(struct file *file, loff_t offset, int origin)
{
	return -ESPIPE;
}

/* --------------------------------------------------------------------- */

static int usb_audio_open_mixdev(struct inode *inode, struct file *file)
{
	int minor = MINOR(inode->i_rdev);
	struct list_head *devs, *mdevs;
	struct usb_mixerdev *ms;
	struct usb_audio_state *s;

	down(&open_sem);
	for (devs = audiodevs.next; devs != &audiodevs; devs = devs->next) {
		s = list_entry(devs, struct usb_audio_state, audiodev);
		for (mdevs = s->mixerlist.next; mdevs != &s->mixerlist; mdevs = mdevs->next) {
			ms = list_entry(mdevs, struct usb_mixerdev, list);
			if (ms->dev_mixer == minor)
				goto mixer_found;
		}
	}
	up(&open_sem);
	return -ENODEV;

 mixer_found:
	if (!s->usbdev) {
		up(&open_sem);
		return -EIO;
	}
	file->private_data = ms;
	s->count++;

	MOD_INC_USE_COUNT;
	up(&open_sem);
	return 0;
}

static int usb_audio_release_mixdev(struct inode *inode, struct file *file)
{
	struct usb_mixerdev *ms = (struct usb_mixerdev *)file->private_data;
	struct usb_audio_state *s = ms->state;

	down(&open_sem);
	release(s);
	MOD_DEC_USE_COUNT;
	return 0;
}

static int usb_audio_ioctl_mixdev(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usb_mixerdev *ms = (struct usb_mixerdev *)file->private_data;
	int i, j, val;

	if (!ms->state->usbdev)
		return -ENODEV;
  
	if (cmd == SOUND_MIXER_INFO) {
		mixer_info info;
		strncpy(info.id, "USB_AUDIO", sizeof(info.id));
		strncpy(info.name, "USB Audio Class Driver", sizeof(info.name));
		info.modify_counter = ms->modcnt;
		if (copy_to_user((void *)arg, &info, sizeof(info)))
			return -EFAULT;
		return 0;
	}
	if (cmd == SOUND_OLD_MIXER_INFO) {
		_old_mixer_info info;
		strncpy(info.id, "USB_AUDIO", sizeof(info.id));
		strncpy(info.name, "USB Audio Class Driver", sizeof(info.name));
		if (copy_to_user((void *)arg, &info, sizeof(info)))
			return -EFAULT;
		return 0;
	}
	if (cmd == OSS_GETVERSION)
		return put_user(SOUND_VERSION, (int *)arg);
	if (_IOC_TYPE(cmd) != 'M' || _IOC_SIZE(cmd) != sizeof(int))
		return -EINVAL;
	if (_IOC_DIR(cmd) == _IOC_READ) {
		switch (_IOC_NR(cmd)) {
		case SOUND_MIXER_RECSRC: /* Arg contains a bit for each recording source */
			/* don't know how to handle this yet */
			return put_user(0, (int *)arg);

		case SOUND_MIXER_DEVMASK: /* Arg contains a bit for each supported device */
			for (val = i = 0; i < ms->numch; i++)
				val |= 1 << ms->ch[i].osschannel;
			return put_user(val, (int *)arg);

		case SOUND_MIXER_RECMASK: /* Arg contains a bit for each supported recording source */
			/* don't know how to handle this yet */
			return put_user(0, (int *)arg);
                        
		case SOUND_MIXER_STEREODEVS: /* Mixer channels supporting stereo */
			for (val = i = 0; i < ms->numch; i++)
				if (ms->ch[i].flags & (MIXFLG_STEREOIN | MIXFLG_STEREOOUT))
					val |= 1 << ms->ch[i].osschannel;
			return put_user(val, (int *)arg);
			
		case SOUND_MIXER_CAPS:
			return put_user(0, (int *)arg);

		default:
			i = _IOC_NR(cmd);
			if (i >= SOUND_MIXER_NRDEVICES)
				return -EINVAL;
			for (j = 0; j < ms->numch; j++) {
				if (ms->ch[j].osschannel == i) {
					return put_user(ms->ch[j].value, (int *)arg);
				}
			}
			return -EINVAL;
		}
	}
	if (_IOC_DIR(cmd) != (_IOC_READ|_IOC_WRITE)) 
		return -EINVAL;
	ms->modcnt++;
	switch (_IOC_NR(cmd)) {
	case SOUND_MIXER_RECSRC: /* Arg contains a bit for each recording source */
		get_user_ret(val, (int *)arg, -EFAULT);
		/* set recording source: val */
		return 0;

	default:
		i = _IOC_NR(cmd);
		if (i >= SOUND_MIXER_NRDEVICES)
			return -EINVAL;
		for (j = 0; j < ms->numch && ms->ch[j].osschannel != i; j++);
		if (j >= ms->numch)
			return -EINVAL;
		get_user_ret(val, (int *)arg, -EFAULT);
		if (wrmixer(ms, j, val))
			return -EIO;
		return put_user(ms->ch[j].value, (int *)arg);
	}
}

static /*const*/ struct file_operations usb_mixer_fops = {
	llseek:		usb_audio_llseek,
	ioctl:		usb_audio_ioctl_mixdev,
	open:		usb_audio_open_mixdev,
	release:	usb_audio_release_mixdev,
};

/* --------------------------------------------------------------------- */

static int drain_out(struct usb_audiodev *as, int nonblock)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	int count, tmo;
	
	if (as->usbout.dma.mapped || !as->usbout.dma.ready)
		return 0;
	add_wait_queue(&as->usbout.dma.wait, &wait);
	for (;;) {
		__set_current_state(TASK_INTERRUPTIBLE);
		spin_lock_irqsave(&as->lock, flags);
		count = as->usbout.dma.count;
		spin_unlock_irqrestore(&as->lock, flags);
		if (count <= 0)
			break;
		if (signal_pending(current))
			break;
		if (nonblock) {
			remove_wait_queue(&as->usbout.dma.wait, &wait);
			set_current_state(TASK_RUNNING);
			return -EBUSY;
		}
		tmo = 3 * HZ * count / as->usbout.dma.srate;
		tmo >>= AFMT_BYTESSHIFT(as->usbout.dma.format);
		if (!schedule_timeout(tmo + 1)) {
			printk(KERN_DEBUG "usbaudio: dma timed out??\n");
			break;
		}
	}
	remove_wait_queue(&as->usbout.dma.wait, &wait);
	set_current_state(TASK_RUNNING);
	if (signal_pending(current))
		return -ERESTARTSYS;
	return 0;
}

/* --------------------------------------------------------------------- */

static ssize_t usb_audio_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
{
	struct usb_audiodev *as = (struct usb_audiodev *)file->private_data;
	DECLARE_WAITQUEUE(wait, current);
	ssize_t ret = 0;
	unsigned long flags;
	unsigned int ptr;
	int cnt, err;

	if (ppos != &file->f_pos)
		return -ESPIPE;
	if (as->usbin.dma.mapped)
		return -ENXIO;
	if (!as->usbin.dma.ready && (ret = prog_dmabuf_in(as)))
		return ret;
	if (!access_ok(VERIFY_WRITE, buffer, count))
		return -EFAULT;
	add_wait_queue(&as->usbin.dma.wait, &wait);
	while (count > 0) {
		spin_lock_irqsave(&as->lock, flags);
		ptr = as->usbin.dma.rdptr;
		cnt = as->usbin.dma.count;
		/* set task state early to avoid wakeup races */
		if (cnt <= 0)
			__set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&as->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			if (usbin_start(as)) {
				if (!ret)
					ret = -ENODEV;
				break;
			}
			if (file->f_flags & O_NONBLOCK) {
				if (!ret)
					ret = -EAGAIN;
				break;
			}
			schedule();
			if (signal_pending(current)) {
				if (!ret)
					ret = -ERESTARTSYS;
				break;
			}
			continue;
		}
		if ((err = dmabuf_copyout_user(&as->usbin.dma, ptr, buffer, cnt))) {
			if (!ret)
				ret = err;
			break;
		}
		ptr += cnt;
		if (ptr >= as->usbin.dma.dmasize)
			ptr -= as->usbin.dma.dmasize;
		spin_lock_irqsave(&as->lock, flags);
		as->usbin.dma.rdptr = ptr;
		as->usbin.dma.count -= cnt;
		spin_unlock_irqrestore(&as->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&as->usbin.dma.wait, &wait);
	return ret;
}

static ssize_t usb_audio_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
{
	struct usb_audiodev *as = (struct usb_audiodev *)file->private_data;
	DECLARE_WAITQUEUE(wait, current);
	ssize_t ret = 0;
	unsigned long flags;
	unsigned int ptr;
	int cnt, err;

	if (ppos != &file->f_pos)
		return -ESPIPE;
	if (as->usbout.dma.mapped)
		return -ENXIO;
	if (!as->usbout.dma.ready && (ret = prog_dmabuf_out(as)))
		return ret;
	if (!access_ok(VERIFY_READ, buffer, count))
		return -EFAULT;
	add_wait_queue(&as->usbout.dma.wait, &wait);
	while (count > 0) {
#if 0
		printk(KERN_DEBUG "usb_audio_write: count %u dma: count %u rdptr %u wrptr %u dmasize %u fragsize %u flags 0x%02x taskst 0x%x\n",
		       count, as->usbout.dma.count, as->usbout.dma.rdptr, as->usbout.dma.wrptr, as->usbout.dma.dmasize, as->usbout.dma.fragsize,
		       as->usbout.flags, current->state);
#endif
		spin_lock_irqsave(&as->lock, flags);
		if (as->usbout.dma.count < 0) {
			as->usbout.dma.count = 0;
			as->usbout.dma.rdptr = as->usbout.dma.wrptr;
		}
		ptr = as->usbout.dma.wrptr;
		cnt = as->usbout.dma.dmasize - as->usbout.dma.count;
		/* set task state early to avoid wakeup races */
		if (cnt <= 0)
			__set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&as->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			if (usbout_start(as)) {
				if (!ret)
					ret = -ENODEV;
				break;
			}
			if (file->f_flags & O_NONBLOCK) {
				if (!ret)
					ret = -EAGAIN;
				break;
			}
			schedule();
			if (signal_pending(current)) {
				if (!ret)
					ret = -ERESTARTSYS;
				break;
			}
			continue;
		}
		if ((err = dmabuf_copyin_user(&as->usbout.dma, ptr, buffer, cnt))) {
			if (!ret)
				ret = err;
			break;
		}
		ptr += cnt;
		if (ptr >= as->usbout.dma.dmasize)
			ptr -= as->usbout.dma.dmasize;
		spin_lock_irqsave(&as->lock, flags);
		as->usbout.dma.wrptr = ptr;
		as->usbout.dma.count += cnt;
		spin_unlock_irqrestore(&as->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
		if (usbout_start(as)) {
			if (!ret)
				ret = -ENODEV;
			break;
		}
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&as->usbout.dma.wait, &wait);
	return ret;
}

static unsigned int usb_audio_poll(struct file *file, struct poll_table_struct *wait)
{
	struct usb_audiodev *as = (struct usb_audiodev *)file->private_data;
	unsigned long flags;
	unsigned int mask = 0;

	if (file->f_mode & FMODE_WRITE) {
		if (!as->usbout.dma.ready)
			prog_dmabuf_out(as);
		poll_wait(file, &as->usbout.dma.wait, wait);
	}
	if (file->f_mode & FMODE_READ) {
		if (!as->usbin.dma.ready)
			prog_dmabuf_in(as);
		poll_wait(file, &as->usbin.dma.wait, wait);
	}
	spin_lock_irqsave(&as->lock, flags);
	if (file->f_mode & FMODE_READ) {
		if (as->usbin.dma.count >= (signed)as->usbin.dma.fragsize)
			mask |= POLLIN | POLLRDNORM;
	}
	if (file->f_mode & FMODE_WRITE) {
		if (as->usbout.dma.mapped) {
			if (as->usbout.dma.count >= (signed)as->usbout.dma.fragsize) 
				mask |= POLLOUT | POLLWRNORM;
		} else {
			if ((signed)as->usbout.dma.dmasize >= as->usbout.dma.count + (signed)as->usbout.dma.fragsize)
				mask |= POLLOUT | POLLWRNORM;
		}
	}
	spin_unlock_irqrestore(&as->lock, flags);
	return mask;
}

static int usb_audio_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct usb_audiodev *as = (struct usb_audiodev *)file->private_data;
	struct dmabuf *db;
	int ret;

	if (vma->vm_flags & VM_WRITE) {
		if ((ret = prog_dmabuf_out(as)) != 0)
			return ret;
		db = &as->usbout.dma;
	} else if (vma->vm_flags & VM_READ) {
		if ((ret = prog_dmabuf_in(as)) != 0)
			return ret;
		db = &as->usbin.dma;
	} else
		return -EINVAL;
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,3,22)
	if (vma->vm_pgoff != 0)
		return -EINVAL;
#endif
	return dmabuf_mmap(db,  vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot);
}

static int usb_audio_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usb_audiodev *as = (struct usb_audiodev *)file->private_data;
	struct usb_audio_state *s = as->state;
	uns