cmpci.c

讲述linux的初始化过程

static /*const*/ struct file_operations cm_audio_fops = {
	owner:		THIS_MODULE,
	llseek:		cm_llseek,
	read:		cm_read,
	write:		cm_write,
	poll:		cm_poll,
	ioctl:		cm_ioctl,
	mmap:		cm_mmap,
	open:		cm_open,
	release:	cm_release,
};

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

static ssize_t cm_midi_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	DECLARE_WAITQUEUE(wait, current);
	ssize_t ret;
	unsigned long flags;
	unsigned ptr;
	int cnt;

	VALIDATE_STATE(s);
	if (ppos != &file->f_pos)
		return -ESPIPE;
	if (!access_ok(VERIFY_WRITE, buffer, count))
		return -EFAULT;
	if (count == 0)
		return 0;
	ret = 0;
	add_wait_queue(&s->midi.iwait, &wait);
	while (count > 0) {
		set_current_state(TASK_INTERRUPTIBLE);
		spin_lock_irqsave(&s->lock, flags);
		ptr = s->midi.ird;
		cnt = MIDIINBUF - ptr;
		if (s->midi.icnt < cnt)
			cnt = s->midi.icnt;
		spin_unlock_irqrestore(&s->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			if (file->f_flags & O_NONBLOCK) 
			{
				if (!ret)
					ret = -EAGAIN;
				break;
			}
			schedule();
			if (signal_pending(current)) 
			{
				if (!ret)
					ret = -ERESTARTSYS;
				break;
			}
			continue;
		}
		if (copy_to_user(buffer, s->midi.ibuf + ptr, cnt)) {
			if (!ret)
				ret = -EFAULT;
			break;
		}
		ptr = (ptr + cnt) % MIDIINBUF;
		spin_lock_irqsave(&s->lock, flags);
		s->midi.ird = ptr;
		s->midi.icnt -= cnt;
		spin_unlock_irqrestore(&s->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
		break;
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&s->midi.iwait, &wait);
	return ret;
}

static ssize_t cm_midi_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	DECLARE_WAITQUEUE(wait, current);
	ssize_t ret;
	unsigned long flags;
	unsigned ptr;
	int cnt;

	VALIDATE_STATE(s);
	if (ppos != &file->f_pos)
		return -ESPIPE;
	if (!access_ok(VERIFY_READ, buffer, count))
		return -EFAULT;
	if (count == 0)
		return 0;
	ret = 0;
	add_wait_queue(&s->midi.owait, &wait);
	while (count > 0) {
		set_current_state(TASK_INTERRUPTIBLE);
		spin_lock_irqsave(&s->lock, flags);
		ptr = s->midi.owr;
		cnt = MIDIOUTBUF - ptr;
		if (s->midi.ocnt + cnt > MIDIOUTBUF)
			cnt = MIDIOUTBUF - s->midi.ocnt;
		if (cnt <= 0)
			cm_handle_midi(s);
		spin_unlock_irqrestore(&s->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			if (file->f_flags & O_NONBLOCK) {
				if (!ret)
					ret = -EAGAIN;
				break;
			}
			schedule();
			if (signal_pending(current)) {
				if (!ret)
					ret = -ERESTARTSYS;
				break;
			}
			continue;
		}
		if (copy_from_user(s->midi.obuf + ptr, buffer, cnt)) {
			if (!ret)
				ret = -EFAULT;
			break;
		}
		ptr = (ptr + cnt) % MIDIOUTBUF;
		spin_lock_irqsave(&s->lock, flags);
		s->midi.owr = ptr;
		s->midi.ocnt += cnt;
		spin_unlock_irqrestore(&s->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
		spin_lock_irqsave(&s->lock, flags);
		cm_handle_midi(s);
		spin_unlock_irqrestore(&s->lock, flags);
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&s->midi.owait, &wait);
	return ret;
}

static unsigned int cm_midi_poll(struct file *file, struct poll_table_struct *wait)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	unsigned long flags;
	unsigned int mask = 0;

	VALIDATE_STATE(s);
	if (file->f_mode & FMODE_WRITE)
		poll_wait(file, &s->midi.owait, wait);
	if (file->f_mode & FMODE_READ)
		poll_wait(file, &s->midi.iwait, wait);
	spin_lock_irqsave(&s->lock, flags);
	if (file->f_mode & FMODE_READ) {
		if (s->midi.icnt > 0)
			mask |= POLLIN | POLLRDNORM;
	}
	if (file->f_mode & FMODE_WRITE) {
		if (s->midi.ocnt < MIDIOUTBUF)
			mask |= POLLOUT | POLLWRNORM;
	}
	spin_unlock_irqrestore(&s->lock, flags);
	return mask;
}

static int cm_midi_open(struct inode *inode, struct file *file)
{
	int minor = MINOR(inode->i_rdev);
	struct cm_state *s = devs;
	unsigned long flags;

	while (s && s->dev_midi != minor)
		s = s->next;
	if (!s)
		return -ENODEV;
       	VALIDATE_STATE(s);
	file->private_data = s;
	/* wait for device to become free */
	down(&s->open_sem);
	while (s->open_mode & (file->f_mode << FMODE_MIDI_SHIFT)) {
		if (file->f_flags & O_NONBLOCK) {
			up(&s->open_sem);
			return -EBUSY;
		}
		up(&s->open_sem);
		interruptible_sleep_on(&s->open_wait);
		if (signal_pending(current))
			return -ERESTARTSYS;
		down(&s->open_sem);
	}
	spin_lock_irqsave(&s->lock, flags);
	if (!(s->open_mode & (FMODE_MIDI_READ | FMODE_MIDI_WRITE))) {
		s->midi.ird = s->midi.iwr = s->midi.icnt = 0;
		s->midi.ord = s->midi.owr = s->midi.ocnt = 0;
		/* enable MPU-401 */
		outb(inb(s->iobase + CODEC_CMI_FUNCTRL1) | 4, s->iobase + CODEC_CMI_FUNCTRL1);
		outb(0xff, s->iomidi+1); /* reset command */
		if (!(inb(s->iomidi+1) & 0x80))
			inb(s->iomidi);
		outb(0x3f, s->iomidi+1); /* uart command */
		if (!(inb(s->iomidi+1) & 0x80))
			inb(s->iomidi);
		s->midi.ird = s->midi.iwr = s->midi.icnt = 0;
		init_timer(&s->midi.timer);
		s->midi.timer.expires = jiffies+1;
		s->midi.timer.data = (unsigned long)s;
		s->midi.timer.function = cm_midi_timer;
		add_timer(&s->midi.timer);
	}
	if (file->f_mode & FMODE_READ) {
		s->midi.ird = s->midi.iwr = s->midi.icnt = 0;
	}
	if (file->f_mode & FMODE_WRITE) {
		s->midi.ord = s->midi.owr = s->midi.ocnt = 0;
	}
	spin_unlock_irqrestore(&s->lock, flags);
	s->open_mode |= (file->f_mode << FMODE_MIDI_SHIFT) & (FMODE_MIDI_READ | FMODE_MIDI_WRITE);
	up(&s->open_sem);
	return 0;
}

static int cm_midi_release(struct inode *inode, struct file *file)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
        DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	unsigned count, tmo;

	VALIDATE_STATE(s);

	lock_kernel();
	if (file->f_mode & FMODE_WRITE) {
		add_wait_queue(&s->midi.owait, &wait);
		for (;;) {
			set_current_state(TASK_INTERRUPTIBLE);
			spin_lock_irqsave(&s->lock, flags);
			count = s->midi.ocnt;
			spin_unlock_irqrestore(&s->lock, flags);
			if (count <= 0)
				break;
			if (signal_pending(current))
				break;
			if (file->f_flags & O_NONBLOCK) {
				remove_wait_queue(&s->midi.owait, &wait);
				set_current_state(TASK_RUNNING);
				return -EBUSY;
			}
			tmo = (count * HZ) / 3100;
			if (!schedule_timeout(tmo ? : 1) && tmo)
				printk(KERN_DEBUG "cmpci: midi timed out??\n");
		}
		remove_wait_queue(&s->midi.owait, &wait);
		set_current_state(TASK_RUNNING);
	}
	down(&s->open_sem);
	s->open_mode &= (~(file->f_mode << FMODE_MIDI_SHIFT)) & (FMODE_MIDI_READ|FMODE_MIDI_WRITE);
	spin_lock_irqsave(&s->lock, flags);
	if (!(s->open_mode & (FMODE_MIDI_READ | FMODE_MIDI_WRITE))) {
		del_timer(&s->midi.timer);		
		outb(0xff, s->iomidi+1); /* reset command */
		if (!(inb(s->iomidi+1) & 0x80))
			inb(s->iomidi);
		/* disable MPU-401 */
		outb(inb(s->iobase + CODEC_CMI_FUNCTRL1) & ~4, s->iobase + CODEC_CMI_FUNCTRL1);
	}
	spin_unlock_irqrestore(&s->lock, flags);
	up(&s->open_sem);
	wake_up(&s->open_wait);
	unlock_kernel();
	return 0;
}

static /*const*/ struct file_operations cm_midi_fops = {
	owner:		THIS_MODULE,
	llseek:		cm_llseek,
	read:		cm_midi_read,
	write:		cm_midi_write,
	poll:		cm_midi_poll,
	open:		cm_midi_open,
	release:	cm_midi_release,
};

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

static int cm_dmfm_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	static const unsigned char op_offset[18] = {
		0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
		0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D,
		0x10, 0x11, 0x12, 0x13, 0x14, 0x15
	};
	struct cm_state *s = (struct cm_state *)file->private_data;
	struct dm_fm_voice v;
	struct dm_fm_note n;
	struct dm_fm_params p;
	unsigned int io;
	unsigned int regb;

	switch (cmd) {		
	case FM_IOCTL_RESET:
		for (regb = 0xb0; regb < 0xb9; regb++) {
			outb(regb, s->iosynth);
			outb(0, s->iosynth+1);
			outb(regb, s->iosynth+2);
			outb(0, s->iosynth+3);
		}
		return 0;

	case FM_IOCTL_PLAY_NOTE:
		if (copy_from_user(&n, (void *)arg, sizeof(n)))
			return -EFAULT;
		if (n.voice >= 18)
			return -EINVAL;
		if (n.voice >= 9) {
			regb = n.voice - 9;
			io = s->iosynth+2;
		} else {
			regb = n.voice;
			io = s->iosynth;
		}
		outb(0xa0 + regb, io);
		outb(n.fnum & 0xff, io+1);
		outb(0xb0 + regb, io);
		outb(((n.fnum >> 8) & 3) | ((n.octave & 7) << 2) | ((n.key_on & 1) << 5), io+1);
		return 0;

	case FM_IOCTL_SET_VOICE:
		if (copy_from_user(&v, (void *)arg, sizeof(v)))
			return -EFAULT;
		if (v.voice >= 18)
			return -EINVAL;
		regb = op_offset[v.voice];
		io = s->iosynth + ((v.op & 1) << 1);
		outb(0x20 + regb, io);
		outb(((v.am & 1) << 7) | ((v.vibrato & 1) << 6) | ((v.do_sustain & 1) << 5) | 
		     ((v.kbd_scale & 1) << 4) | (v.harmonic & 0xf), io+1);
		outb(0x40 + regb, io);
		outb(((v.scale_level & 0x3) << 6) | (v.volume & 0x3f), io+1);
		outb(0x60 + regb, io);
		outb(((v.attack & 0xf) << 4) | (v.decay & 0xf), io+1);
		outb(0x80 + regb, io);
		outb(((v.sustain & 0xf) << 4) | (v.release & 0xf), io+1);
		outb(0xe0 + regb, io);
		outb(v.waveform & 0x7, io+1);
		if (n.voice >= 9) {
			regb = n.voice - 9;
			io = s->iosynth+2;
		} else {
			regb = n.voice;
			io = s->iosynth;
		}
		outb(0xc0 + regb, io);
		outb(((v.right & 1) << 5) | ((v.left & 1) << 4) | ((v.feedback & 7) << 1) |
		     (v.connection & 1), io+1);
		return 0;
		
	case FM_IOCTL_SET_PARAMS:
		if (copy_from_user(&p, (void *)arg, sizeof(p)))
			return -EFAULT;
		outb(0x08, s->iosynth);
		outb((p.kbd_split & 1) << 6, s->iosynth+1);
		outb(0xbd, s->iosynth);
		outb(((p.am_depth & 1) << 7) | ((p.vib_depth & 1) << 6) | ((p.rhythm & 1) << 5) | ((p.bass & 1) << 4) |
		     ((p.snare & 1) << 3) | ((p.tomtom & 1) << 2) | ((p.cymbal & 1) << 1) | (p.hihat & 1), s->iosynth+1);
		return 0;

	case FM_IOCTL_SET_OPL:
		outb(4, s->iosynth+2);
		outb(arg, s->iosynth+3);
		return 0;

	case FM_IOCTL_SET_MODE:
		outb(5, s->iosynth+2);
		outb(arg & 1, s->iosynth+3);
		return 0;

	default:
		return -EINVAL;
	}
}

static int cm_dmfm_open(struct inode *inode, struct file *file)
{
	int minor = MINOR(inode->i_rdev);
	struct cm_state *s = devs;

	while (s && s->dev_dmfm != minor)
		s = s->next;
	if (!s)
		return -ENODEV;
       	VALIDATE_STATE(s);
	file->private_data = s;
	/* wait for device to become free */
	down(&s->open_sem);
	while (s->open_mode & FMODE_DMFM) {
		if (file->f_flags & O_NONBLOCK) {
			up(&s->open_sem);
			return -EBUSY;
		}
		up(&s->open_sem);
		interruptible_sleep_on(&s->open_wait);
		if (signal_pending(current))
			return -ERESTARTSYS;
		down(&s->open_sem);
	}
	/* init the stuff */
	outb(1, s->iosynth);
	outb(0x20, s->iosynth+1); /* enable waveforms */
	outb(4, s->iosynth+2);
	outb(0, s->iosynth+3);  /* no 4op enabled */
	outb(5, s->iosynth+2);
	outb(1, s->iosynth+3);  /* enable OPL3 */
	s->open_mode |= FMODE_DMFM;
	up(&s->open_sem);
	return 0;
}

static int cm_dmfm_release(struct inode *inode, struct file *file)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	unsigned int regb;

	VALIDATE_STATE(s);
	lock_kernel();
	down(&s->open_sem);
	s->open_mode &= ~FMODE_DMFM;
	for (regb = 0xb0; regb < 0xb9; regb++) {
		outb(regb, s->iosynth);
		outb(0, s->iosynth+1);
		outb(regb, s->iosynth+2);
		outb(0, s->iosynth+3);
	}
	up(&s->open_sem);
	wake_up(&s->open_wait);
	unlock_kernel();
	return 0;
}

static /*const*/ struct file_operations cm_dmfm_fops = {
	owner:		THIS_MODULE,
	llseek:		cm_llseek,
	ioctl:		cm_dmfm_ioctl,
	open:		cm_dmfm_open,
	release:	cm_dmfm_release,
};

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

/* maximum number of device