cmpci.c

讲述linux的初始化过程

		break;
				
	case MT_5MUTE:
	default:
		rl = 100 - 3 * ((l >> 3) & 31);
		rr = 100 - 3 * ((r >> 3) & 31);
		break;
				
	case MT_6MUTE:
		rl = 100 - 3 * (l & 63) / 2;
		rr = 100 - 3 * (r & 63) / 2;
		break;
	}
	if (l & 0x80)
		rl = 0;
	if (r & 0x80)
		rr = 0;
	return put_user((rr << 8) | rl, arg);
}

#else /* OSS_DOCUMENTED_MIXER_SEMANTICS */

static const unsigned char volidx[SOUND_MIXER_NRDEVICES] = 
{
	[SOUND_MIXER_CD]     = 1,
	[SOUND_MIXER_LINE]   = 2,
	[SOUND_MIXER_MIC]    = 3,
	[SOUND_MIXER_SYNTH]  = 4,
	[SOUND_MIXER_VOLUME] = 5,
	[SOUND_MIXER_PCM]    = 6
};

#endif /* OSS_DOCUMENTED_MIXER_SEMANTICS */

static unsigned mixer_recmask(struct cm_state *s)
{
	unsigned long flags;
	int i, j, k;

	spin_lock_irqsave(&s->lock, flags);
	j = rdmixer(s, DSP_MIX_ADCMIXIDX_L);
	spin_unlock_irqrestore(&s->lock, flags);
	j &= 0x7f;
	for (k = i = 0; i < SOUND_MIXER_NRDEVICES; i++)
		if (j & mixtable[i].rec)
			k |= 1 << i;
	return k;
}

static int mixer_ioctl(struct cm_state *s, unsigned int cmd, unsigned long arg)
{
	unsigned long flags;
	int i, val, j;
	unsigned char l, r, rl, rr;

	VALIDATE_STATE(s);
        if (cmd == SOUND_MIXER_INFO) {
		mixer_info info;
		strncpy(info.id, "cmpci", sizeof(info.id));
		strncpy(info.name, "C-Media PCI", sizeof(info.name));
		info.modify_counter = s->mix.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, "cmpci", sizeof(info.id));
		strncpy(info.name, "C-Media cmpci", 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' || _SIOC_SIZE(cmd) != sizeof(int))
                return -EINVAL;
        if (_SIOC_DIR(cmd) == _SIOC_READ) {
                switch (_IOC_NR(cmd)) {
                case SOUND_MIXER_RECSRC: /* Arg contains a bit for each recording source */
			return put_user(mixer_recmask(s), (int *)arg);
			
                case SOUND_MIXER_OUTSRC: /* Arg contains a bit for each recording source */
			return put_user(mixer_recmask(s), (int *)arg);//need fix
			
                case SOUND_MIXER_DEVMASK: /* Arg contains a bit for each supported device */
			for (val = i = 0; i < SOUND_MIXER_NRDEVICES; i++)
				if (mixtable[i].type)
					val |= 1 << i;
			return put_user(val, (int *)arg);

                case SOUND_MIXER_RECMASK: /* Arg contains a bit for each supported recording source */
			for (val = i = 0; i < SOUND_MIXER_NRDEVICES; i++)
				if (mixtable[i].rec)
					val |= 1 << i;
			return put_user(val, (int *)arg);
			
                case SOUND_MIXER_OUTMASK: /* Arg contains a bit for each supported recording source */
			for (val = i = 0; i < SOUND_MIXER_NRDEVICES; i++)
				if (mixtable[i].play)
					val |= 1 << i;
			return put_user(val, (int *)arg);
			
                 case SOUND_MIXER_STEREODEVS: /* Mixer channels supporting stereo */
			for (val = i = 0; i < SOUND_MIXER_NRDEVICES; i++)
				if (mixtable[i].type && mixtable[i].type != MT_4MUTEMONO)
					val |= 1 << i;
			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 || !mixtable[i].type)
                                return -EINVAL;
#ifdef OSS_DOCUMENTED_MIXER_SEMANTICS
			return return_mixval(s, i, (int *)arg);
#else /* OSS_DOCUMENTED_MIXER_SEMANTICS */
			if (!volidx[i])
				return -EINVAL;
			return put_user(s->mix.vol[volidx[i]-1], (int *)arg);
#endif /* OSS_DOCUMENTED_MIXER_SEMANTICS */
		}
	}
        if (_SIOC_DIR(cmd) != (_SIOC_READ|_SIOC_WRITE)) 
		return -EINVAL;
	s->mix.modcnt++;
	switch (_IOC_NR(cmd)) {
	case SOUND_MIXER_RECSRC: /* Arg contains a bit for each recording source */
		if (get_user(val, (int *)arg))
			return -EFAULT;
		i = hweight32(val);
		for (j = i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
			if (!(val & (1 << i)))
				continue;
			if (!mixtable[i].rec) {
				val &= ~(1 << i);
				continue;
			}
			j |= mixtable[i].rec;
		}
		spin_lock_irqsave(&s->lock, flags);
		wrmixer(s, DSP_MIX_ADCMIXIDX_L, j);
		wrmixer(s, DSP_MIX_ADCMIXIDX_R, (j & 1) | (j>>1));
		spin_unlock_irqrestore(&s->lock, flags);
		return 0;

	case SOUND_MIXER_OUTSRC: /* Arg contains a bit for each recording source */
		if (get_user(val, (int *)arg))
			return -EFAULT;
		for (j = i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
			if (!(val & (1 << i)))
				continue;
			if (!mixtable[i].play) {
				val &= ~(1 << i);
				continue;
			}
			j |= mixtable[i].play;
		}
		spin_lock_irqsave(&s->lock, flags);
		frobindir(s, DSP_MIX_OUTMIXIDX, 0x1f, j);
		spin_unlock_irqrestore(&s->lock, flags);
		return 0;

		default:
		i = _IOC_NR(cmd);
		if (i >= SOUND_MIXER_NRDEVICES || !mixtable[i].type)
			return -EINVAL;
		if (get_user(val, (int *)arg))
			return -EFAULT;
		l = val & 0xff;
		r = (val >> 8) & 0xff;
		if (l > 100)
			l = 100;
		if (r > 100)
			r = 100;
		spin_lock_irqsave(&s->lock, flags);
		switch (mixtable[i].type) {
		case MT_4:
			if (l >= 10)
				l -= 10;
			if (r >= 10)
				r -= 10;
			frobindir(s, mixtable[i].left, 0xf0, l / 6);
			frobindir(s, mixtable[i].right, 0xf0, l / 6);
			break;

		case MT_4MUTEMONO:
			rl = (l < 4 ? 0 : (l - 5) / 3) & 31;
			rr = (rl >> 2) & 7;
			wrmixer(s, mixtable[i].left, rl<<3);
			outb((inb(s->iobase + CODEC_CMI_MIXER2) & ~0x0e) | rr<<1, s->iobase + CODEC_CMI_MIXER2);
			break;
			
		case MT_5MUTEMONO:
			r = l;
			rl = l < 4 ? 0 : (l - 5) / 3;
			rr = rl >> 2;
 			wrmixer(s, mixtable[i].left, rl<<3);
			outb((inb(s->iobase + CODEC_CMI_MIXER2) & ~0x0e) | rr<<1, s->iobase + CODEC_CMI_MIXER2);
			break;
				
		case MT_5MUTE:
			rl = l < 4 ? 0 : (l - 5) / 3;
			rr = r < 4 ? 0 : (r - 5) / 3;
 			wrmixer(s, mixtable[i].left, rl<<3);
			wrmixer(s, mixtable[i].right, rr<<3);
			break;
				
		case MT_6MUTE:
			if (l < 6)
				rl = 0x00;
			else
				rl = l * 2 / 3;
			if (r < 6)
				rr = 0x00;
			else
				rr = r * 2 / 3;
			wrmixer(s, mixtable[i].left, rl);
			wrmixer(s, mixtable[i].right, rr);
			break;
		}
		spin_unlock_irqrestore(&s->lock, flags);
#ifdef OSS_DOCUMENTED_MIXER_SEMANTICS
                return return_mixval(s, i, (int *)arg);
#else /* OSS_DOCUMENTED_MIXER_SEMANTICS */
		if (!volidx[i])
			return -EINVAL;
		s->mix.vol[volidx[i]-1] = val;
		return put_user(s->mix.vol[volidx[i]-1], (int *)arg);
#endif /* OSS_DOCUMENTED_MIXER_SEMANTICS */
	}
}

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

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

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

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

	while (s && s->dev_mixer != minor)
		s = s->next;
	if (!s)
		return -ENODEV;
       	VALIDATE_STATE(s);
	file->private_data = s;
	return 0;
}

static int cm_release_mixdev(struct inode *inode, struct file *file)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	
	VALIDATE_STATE(s);
	return 0;
}

static int cm_ioctl_mixdev(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	return mixer_ioctl((struct cm_state *)file->private_data, cmd, arg);
}

static /*const*/ struct file_operations cm_mixer_fops = {
	owner:		THIS_MODULE,
	llseek:		cm_llseek,
	ioctl:		cm_ioctl_mixdev,
	open:		cm_open_mixdev,
	release:	cm_release_mixdev,
};

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

static int drain_dac(struct cm_state *s, int nonblock)
{
        DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	int count, tmo;

	if (s->dma_dac.mapped || !s->dma_dac.ready)
		return 0;
        add_wait_queue(&s->dma_dac.wait, &wait);
        for (;;) {
		set_current_state(TASK_INTERRUPTIBLE);
                spin_lock_irqsave(&s->lock, flags);
		count = s->dma_dac.count;
                spin_unlock_irqrestore(&s->lock, flags);
		if (count <= 0)
			break;
		if (signal_pending(current))
                        break;
                if (nonblock) {
                        remove_wait_queue(&s->dma_dac.wait, &wait);
                        current->state = TASK_RUNNING;
                        return -EBUSY;
                }
		tmo = (count * HZ) / s->ratedac;
		tmo >>= sample_shift[(s->fmt >> CM_CFMT_DACSHIFT) & CM_CFMT_MASK];
		if (!schedule_timeout(tmo ? : 1) && tmo)
			printk(KERN_DEBUG "cmpci: dma timed out??\n");
        }
        remove_wait_queue(&s->dma_dac.wait, &wait);
        current->state = TASK_RUNNING;
        if (signal_pending(current))
                return -ERESTARTSYS;
        return 0;
}

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

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

	VALIDATE_STATE(s);
	if (ppos != &file->f_pos)
		return -ESPIPE;
	if (s->dma_adc.mapped)
		return -ENXIO;
	if (!s->dma_adc.ready && (ret = prog_dmabuf(s, 1)))
		return ret;
	if (!access_ok(VERIFY_WRITE, buffer, count))
		return -EFAULT;
	ret = 0;
#if 0
   spin_lock_irqsave(&s->lock, flags);
   cm_update_ptr(s);
   spin_unlock_irqrestore(&s->lock, flags);
#endif
	while (count > 0) {
		spin_lock_irqsave(&s->lock, flags);
		swptr = s->dma_adc.swptr;
		cnt = s->dma_adc.dmasize-swptr;
		if (s->dma_adc.count < cnt)
			cnt = s->dma_adc.count;
		spin_unlock_irqrestore(&s->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			start_adc(s);
			if (file->f_flags & O_NONBLOCK)
				return ret ? ret : -EAGAIN;
			if (!interruptible_sleep_on_timeout(&s->dma_adc.wait, HZ)) {
				printk(KERN_DEBUG "cmpci: read: chip lockup? dmasz %u fragsz %u count %i hwptr %u swptr %u\n",
				       s->dma_adc.dmasize, s->dma_adc.fragsize, s->dma_adc.count,
				       s->dma_adc.hwptr, s->dma_adc.swptr);
				stop_adc(s);
				spin_lock_irqsave(&s->lock, flags);
				set_dmaadc(s, virt_to_bus(s->dma_adc.rawbuf), s->dma_adc.dmasamples);
				/* program sample counts */
				outw(s->dma_adc.fragsamples-1, s->iobase + CODEC_CMI_CH1_FRAME2 + 2);
				s->dma_adc.count = s->dma_adc.hwptr = s->dma_adc.swptr = 0;
				spin_unlock_irqrestore(&s->lock, flags);
			}
			if (signal_pending(current))
				return ret ? ret : -ERESTARTSYS;
			continue;
		}
		if (copy_to_user(buffer, s->dma_adc.rawbuf + swptr, cnt))
			return ret ? ret : -EFAULT;
		swptr = (swptr + cnt) % s->dma_adc.dmasize;
		spin_lock_irqsave(&s->lock, flags);
		s->dma_adc.swptr = swptr;
		s->dma_adc.count -= cnt;
		spin_unlock_irqrestore(&s->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
		start_adc(s);
	}
	return ret;
}

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

	VALIDATE_STATE(s);
	if (ppos != &file->f_pos)
		return -ESPIPE;
	if (s->dma_dac.mapped)
		return -ENXIO;
	if (!s->dma_dac.ready && (ret = prog_dmabuf(s, 0)))
		return ret;
	if (!access_ok(VERIFY_READ, buffer, count))
		return -EFAULT;
	ret = 0;
#if 0
   spin_lock_irqsave(&s->lock, flags);
   cm_update_ptr(s);
   spin_unlock_irqrestore(&s->lock, flags);
#endif
	while (count > 0) {
		spin_lock_irqsave(&s->lock, flags);
		if (s->dma_dac.count < 0) {
			s->dma_dac.count = 0;
			s->dma_dac.swptr = s->dma_dac.hwptr;
		}
		swptr = s->dma_dac.swptr;
		cnt = s->dma_dac.dmasize-swptr;
		if (s->dma_dac.count + cnt > s->dma_dac.dmasize)
			cnt = s->dma_dac.dmasize - s->dma_dac.count;
		spin_unlock_irqrestore(&s->lock, flags);
		if (cnt > count)
			cnt = count;
		if (cnt <= 0) {
			start_dac(s);
			if (file->f_flags & O_NONBLOCK)
				return ret ? ret : -EAGAIN;
			if (!interruptible_sleep_on_timeout(&s->dma_dac.wait, HZ)) {
				printk(KERN_DEBUG "cmpci: write: chip lockup? dmasz %u fragsz %u count %i hwptr %u swptr %u\n",
				       s->dma_dac.dmasize, s->dma_dac.fragsize, s->dma_dac.count,
				       s->dma_dac.hwptr, s->dma_dac.swptr);
				stop_dac(s);
				spin_lock_irqsave(&s->lock, flags);
				set_dmadac(s, virt_to_bus(s->dma_dac.rawbuf), s->dma_dac.dmasamples);
				/* program sample counts */
				outw(s->dma_dac.fragsamples-1, s->iobase + CODEC_CMI_CH0_FRAME2 + 2);
				s->dma_dac.count = s->dma_dac.hwptr = s->dma_dac.swptr = 0;
				spin_unlock_irqrestore(&s->lock, flags);
			}
			if (signal_pending(current))
				return ret ? ret : -ERESTARTSYS;
			continue;
		}
		if (copy_from_user(s->dma_dac.rawbuf + swptr, buffer, cnt))
			return ret ? ret : -EFAULT;
		swptr = (swptr + cnt) % s->dma_dac.dmasize;
		spin_lock_irqsave(&s->lock, flags);
		s->dma_dac.swptr = swptr;
		s->dma_dac.count += cnt;
		s->dma_dac.endcleared = 0;
		spin_unlock_irqrestore(&s->lock, flags);
		count -= cnt;
		buffer += cnt;
		ret += cnt;
		start_dac(s);
	}
	return ret;