cmpci.c

讲述linux的初始化过程

}

/* No kernel lock - fine (we have our own spinlock) */
static unsigned int cm_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) {
		if (!s->dma_dac.ready && prog_dmabuf(s, 0))
			return 0;
		poll_wait(file, &s->dma_dac.wait, wait);
	}
	if (file->f_mode & FMODE_READ) {
		if (!s->dma_adc.ready && prog_dmabuf(s, 1))
			return 0;
		poll_wait(file, &s->dma_adc.wait, wait);
	}

	spin_lock_irqsave(&s->lock, flags);
	cm_update_ptr(s);
	if (file->f_mode & FMODE_READ) {
		if (s->dma_adc.count >= (signed)s->dma_adc.fragsize)
			mask |= POLLIN | POLLRDNORM;
	}
	if (file->f_mode & FMODE_WRITE) {
		if (s->dma_dac.mapped) {
			if (s->dma_dac.count >= (signed)s->dma_dac.fragsize) 
				mask |= POLLOUT | POLLWRNORM;
		} else {
			if ((signed)s->dma_dac.dmasize >= s->dma_dac.count + (signed)s->dma_dac.fragsize)
				mask |= POLLOUT | POLLWRNORM;
		}
	}
	spin_unlock_irqrestore(&s->lock, flags);
	return mask;
}

static int cm_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	struct dmabuf *db;
	int ret = -EINVAL;
	unsigned long size;

	VALIDATE_STATE(s);
	lock_kernel();
	if (vma->vm_flags & VM_WRITE) {
		if ((ret = prog_dmabuf(s, 1)) != 0)
			goto out;
		db = &s->dma_dac;
	} else if (vma->vm_flags & VM_READ) {
		if ((ret = prog_dmabuf(s, 0)) != 0)
			goto out;
		db = &s->dma_adc;
	} else 
		goto out;
	ret = -EINVAL;
	if (vma->vm_pgoff != 0)
		goto out;
	size = vma->vm_end - vma->vm_start;
	if (size > (PAGE_SIZE << db->buforder))
		goto out;
	ret = -EAGAIN;
	if (remap_page_range(vma->vm_start, virt_to_phys(db->rawbuf), size, vma->vm_page_prot))
		goto out;
	db->mapped = 1;
	ret = 0;
out:
	unlock_kernel();
	return ret;
}

static int cm_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct cm_state *s = (struct cm_state *)file->private_data;
	unsigned long flags;
        audio_buf_info abinfo;
        count_info cinfo;
	int val, mapped, ret;
	unsigned char fmtm, fmtd;

	VALIDATE_STATE(s);
        mapped = ((file->f_mode & FMODE_WRITE) && s->dma_dac.mapped) ||
		((file->f_mode & FMODE_READ) && s->dma_adc.mapped);
	switch (cmd) {
	case OSS_GETVERSION:
		return put_user(SOUND_VERSION, (int *)arg);

	case SNDCTL_DSP_SYNC:
		if (file->f_mode & FMODE_WRITE)
			return drain_dac(s, 0/*file->f_flags & O_NONBLOCK*/);
		return 0;
		
	case SNDCTL_DSP_SETDUPLEX:
		return 0;

	case SNDCTL_DSP_GETCAPS:
		return put_user(DSP_CAP_DUPLEX | DSP_CAP_REALTIME | DSP_CAP_TRIGGER | DSP_CAP_MMAP, (int *)arg);
		
        case SNDCTL_DSP_RESET:
		if (file->f_mode & FMODE_WRITE) {
			stop_dac(s);
			synchronize_irq();
			s->dma_dac.swptr = s->dma_dac.hwptr = s->dma_dac.count = s->dma_dac.total_bytes = 0;
		}
		if (file->f_mode & FMODE_READ) {
			stop_adc(s);
			synchronize_irq();
			s->dma_adc.swptr = s->dma_adc.hwptr = s->dma_adc.count = s->dma_adc.total_bytes = 0;
		}
		return 0;

        case SNDCTL_DSP_SPEED:
                if (get_user(val, (int *)arg))
			return -EFAULT;
		if (val >= 0) {
			if (file->f_mode & FMODE_READ) {
				stop_adc(s);
				s->dma_adc.ready = 0;
				set_adc_rate(s, val);
			}
			if (file->f_mode & FMODE_WRITE) {
				stop_dac(s);
				s->dma_dac.ready = 0;
				set_dac_rate(s, val);
			}
		}
		return put_user((file->f_mode & FMODE_READ) ? s->rateadc : s->ratedac, (int *)arg);
		
        case SNDCTL_DSP_STEREO:
                if (get_user(val, (int *)arg))
			return -EFAULT;
		fmtd = 0;
		fmtm = ~0;
		if (file->f_mode & FMODE_READ) {
			stop_adc(s);
			s->dma_adc.ready = 0;
			if (val)
				fmtd |= CM_CFMT_STEREO << CM_CFMT_ADCSHIFT;
			else
				fmtm &= ~(CM_CFMT_STEREO << CM_CFMT_ADCSHIFT);
		}
		if (file->f_mode & FMODE_WRITE) {
			stop_dac(s);
			s->dma_dac.ready = 0;
			if (val)
				fmtd |= CM_CFMT_STEREO << CM_CFMT_DACSHIFT;
			else
				fmtm &= ~(CM_CFMT_STEREO << CM_CFMT_DACSHIFT);
		}
		set_fmt(s, fmtm, fmtd);
		return 0;

        case SNDCTL_DSP_CHANNELS:
                if (get_user(val, (int *)arg))
			return -EFAULT;
		if (val != 0) {
			fmtd = 0;
			fmtm = ~0;
			if (file->f_mode & FMODE_READ) {
				stop_adc(s);
				s->dma_adc.ready = 0;
				if (val >= 2)
					fmtd |= CM_CFMT_STEREO << CM_CFMT_ADCSHIFT;
				else
					fmtm &= ~(CM_CFMT_STEREO << CM_CFMT_ADCSHIFT);
			}
			if (file->f_mode & FMODE_WRITE) {
				stop_dac(s);
				s->dma_dac.ready = 0;
				if (val >= 2)
					fmtd |= CM_CFMT_STEREO << CM_CFMT_DACSHIFT;
				else
					fmtm &= ~(CM_CFMT_STEREO << CM_CFMT_DACSHIFT);
			}
			set_fmt(s, fmtm, fmtd);
		}
		return put_user((s->fmt & ((file->f_mode & FMODE_READ) ? (CM_CFMT_STEREO << CM_CFMT_ADCSHIFT) 
					   : (CM_CFMT_STEREO << CM_CFMT_DACSHIFT))) ? 2 : 1, (int *)arg);
		
	case SNDCTL_DSP_GETFMTS: /* Returns a mask */
                return put_user(AFMT_S16_LE|AFMT_U8, (int *)arg);
		
	case SNDCTL_DSP_SETFMT: /* Selects ONE fmt*/
		if (get_user(val, (int *)arg))
			return -EFAULT;
		if (val != AFMT_QUERY) {
			fmtd = 0;
			fmtm = ~0;
			if (file->f_mode & FMODE_READ) {
				stop_adc(s);
				s->dma_adc.ready = 0;
				if (val == AFMT_S16_LE)
					fmtd |= CM_CFMT_16BIT << CM_CFMT_ADCSHIFT;
				else
					fmtm &= ~(CM_CFMT_16BIT << CM_CFMT_ADCSHIFT);
			}
			if (file->f_mode & FMODE_WRITE) {
				stop_dac(s);
				s->dma_dac.ready = 0;
				if (val == AFMT_S16_LE)
					fmtd |= CM_CFMT_16BIT << CM_CFMT_DACSHIFT;
				else
					fmtm &= ~(CM_CFMT_16BIT << CM_CFMT_DACSHIFT);
			}
			set_fmt(s, fmtm, fmtd);
		}
		return put_user((s->fmt & ((file->f_mode & FMODE_READ) ? (CM_CFMT_16BIT << CM_CFMT_ADCSHIFT) 
					   : (CM_CFMT_16BIT << CM_CFMT_DACSHIFT))) ? AFMT_S16_LE : AFMT_U8, (int *)arg);
		
	case SNDCTL_DSP_POST:
                return 0;

        case SNDCTL_DSP_GETTRIGGER:
		val = 0;
		if (file->f_mode & FMODE_READ && s->enable & CM_CENABLE_RE) 
			val |= PCM_ENABLE_INPUT;
		if (file->f_mode & FMODE_WRITE && s->enable & CM_CENABLE_PE) 
			val |= PCM_ENABLE_OUTPUT;
		return put_user(val, (int *)arg);
		
	case SNDCTL_DSP_SETTRIGGER:
		if (get_user(val, (int *)arg))
			return -EFAULT;
		if (file->f_mode & FMODE_READ) {
			if (val & PCM_ENABLE_INPUT) {
				if (!s->dma_adc.ready && (ret =  prog_dmabuf(s, 1)))
					return ret;
				start_adc(s);
			} else
				stop_adc(s);
		}
		if (file->f_mode & FMODE_WRITE) {
			if (val & PCM_ENABLE_OUTPUT) {
				if (!s->dma_dac.ready && (ret = prog_dmabuf(s, 0)))
					return ret;
				start_dac(s);
			} else
				stop_dac(s);
		}
		return 0;

	case SNDCTL_DSP_GETOSPACE:
		if (!(file->f_mode & FMODE_WRITE))
			return -EINVAL;
		if (!s->dma_dac.ready && (ret = prog_dmabuf(s, 0)))
			return ret;
		spin_lock_irqsave(&s->lock, flags);
		cm_update_ptr(s);
		abinfo.fragsize = s->dma_dac.fragsize;
                abinfo.bytes = s->dma_dac.dmasize - s->dma_dac.count;
                abinfo.fragstotal = s->dma_dac.numfrag;
                abinfo.fragments = abinfo.bytes >> s->dma_dac.fragshift;      
		spin_unlock_irqrestore(&s->lock, flags);
		return copy_to_user((void *)arg, &abinfo, sizeof(abinfo)) ? -EFAULT : 0;

	case SNDCTL_DSP_GETISPACE:
		if (!(file->f_mode & FMODE_READ))
			return -EINVAL;
		if (!s->dma_adc.ready && (ret =  prog_dmabuf(s, 1)))
			return ret;
		spin_lock_irqsave(&s->lock, flags);
		cm_update_ptr(s);
		abinfo.fragsize = s->dma_adc.fragsize;
                abinfo.bytes = s->dma_adc.count;
                abinfo.fragstotal = s->dma_adc.numfrag;
                abinfo.fragments = abinfo.bytes >> s->dma_adc.fragshift;      
		spin_unlock_irqrestore(&s->lock, flags);
		return copy_to_user((void *)arg, &abinfo, sizeof(abinfo)) ? -EFAULT : 0;
		
        case SNDCTL_DSP_NONBLOCK:
                file->f_flags |= O_NONBLOCK;
                return 0;

        case SNDCTL_DSP_GETODELAY:
		if (!(file->f_mode & FMODE_WRITE))
			return -EINVAL;
		if (!s->dma_dac.ready && (ret = prog_dmabuf(s, 0)))
			return ret;
		spin_lock_irqsave(&s->lock, flags);
		cm_update_ptr(s);
                val = s->dma_dac.count;
		spin_unlock_irqrestore(&s->lock, flags);
		return put_user(val, (int *)arg);

        case SNDCTL_DSP_GETIPTR:
		if (!(file->f_mode & FMODE_READ))
			return -EINVAL;
		if (!s->dma_adc.ready && (ret =  prog_dmabuf(s, 1)))
			return ret;
		spin_lock_irqsave(&s->lock, flags);
		cm_update_ptr(s);
                cinfo.bytes = s->dma_adc.total_bytes;
                cinfo.blocks = s->dma_adc.count >> s->dma_adc.fragshift;
                cinfo.ptr = s->dma_adc.hwptr;
		if (s->dma_adc.mapped)
			s->dma_adc.count &= s->dma_adc.fragsize-1;
		spin_unlock_irqrestore(&s->lock, flags);
                return copy_to_user((void *)arg, &cinfo, sizeof(cinfo));

        case SNDCTL_DSP_GETOPTR:
		if (!(file->f_mode & FMODE_WRITE))
			return -EINVAL;
		if (!s->dma_dac.ready && (ret = prog_dmabuf(s, 0)))
			return ret;
		spin_lock_irqsave(&s->lock, flags);
		cm_update_ptr(s);
                cinfo.bytes = s->dma_dac.total_bytes;
                cinfo.blocks = s->dma_dac.count >> s->dma_dac.fragshift;
                cinfo.ptr = s->dma_dac.hwptr;
		if (s->dma_dac.mapped)
			s->dma_dac.count &= s->dma_dac.fragsize-1;
		spin_unlock_irqrestore(&s->lock, flags);
                return copy_to_user((void *)arg, &cinfo, sizeof(cinfo));

        case SNDCTL_DSP_GETBLKSIZE:
		if (file->f_mode & FMODE_WRITE) {
			if ((val = prog_dmabuf(s, 0)))
				return val;
			return put_user(s->dma_dac.fragsize, (int *)arg);
		}
		if ((val = prog_dmabuf(s, 1)))
			return val;
		return put_user(s->dma_adc.fragsize, (int *)arg);

        case SNDCTL_DSP_SETFRAGMENT:
                if (get_user(val, (int *)arg))
			return -EFAULT;
		if (file->f_mode & FMODE_READ) {
			s->dma_adc.ossfragshift = val & 0xffff;
			s->dma_adc.ossmaxfrags = (val >> 16) & 0xffff;
			if (s->dma_adc.ossfragshift < 4)
				s->dma_adc.ossfragshift = 4;
			if (s->dma_adc.ossfragshift > 15)
				s->dma_adc.ossfragshift = 15;
			if (s->dma_adc.ossmaxfrags < 4)
				s->dma_adc.ossmaxfrags = 4;
		}
		if (file->f_mode & FMODE_WRITE) {
			s->dma_dac.ossfragshift = val & 0xffff;
			s->dma_dac.ossmaxfrags = (val >> 16) & 0xffff;
			if (s->dma_dac.ossfragshift < 4)
				s->dma_dac.ossfragshift = 4;
			if (s->dma_dac.ossfragshift > 15)
				s->dma_dac.ossfragshift = 15;
			if (s->dma_dac.ossmaxfrags < 4)
				s->dma_dac.ossmaxfrags = 4;
		}
		return 0;

        case SNDCTL_DSP_SUBDIVIDE:
		if ((file->f_mode & FMODE_READ && s->dma_adc.subdivision) ||
		    (file->f_mode & FMODE_WRITE && s->dma_dac.subdivision))
			return -EINVAL;
                if (get_user(val, (int *)arg))
			return -EFAULT;
		if (val != 1 && val != 2 && val != 4)
			return -EINVAL;
		if (file->f_mode & FMODE_READ)
			s->dma_adc.subdivision = val;
		if (file->f_mode & FMODE_WRITE)
			s->dma_dac.subdivision = val;
		return 0;

        case SOUND_PCM_READ_RATE:
		return put_user((file->f_mode & FMODE_READ) ? s->rateadc : s->ratedac, (int *)arg);

        case SOUND_PCM_READ_CHANNELS:
		return put_user((s->fmt & ((file->f_mode & FMODE_READ) ? (CM_CFMT_STEREO << CM_CFMT_ADCSHIFT) : (CM_CFMT_STEREO << CM_CFMT_DACSHIFT))) ? 2 : 1, (int *)arg);

        case SOUND_PCM_READ_BITS:
		return put_user((s->fmt & ((file->f_mode & FMODE_READ) ? (CM_CFMT_16BIT << CM_CFMT_ADCSHIFT) : (CM_CFMT_16BIT << CM_CFMT_DACSHIFT))) ? 16 : 8, (int *)arg);

        case SOUND_PCM_READ_FILTER:
		return put_user((file->f_mode & FMODE_READ) ? s->rateadc : s->ratedac, (int *)arg);

        case SOUND_PCM_WRITE_FILTER:
        case SNDCTL_DSP_SETSYNCRO:
                return -EINVAL;
		
	}
	return mixer_ioctl(s, cmd, arg);
}

static int cm_open(struct inode *inode, struct file *file)
{
	int minor = MINOR(inode->i_rdev);
	struct cm_state *s = devs;
	unsigned char fmtm = ~0, fmts = 0;

	while (s && ((s->dev_audio ^ minor) & ~0xf))
		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) {
		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);
	}
	if (file->f_mode & FMODE_READ) {
		fmtm &= ~((CM_CFMT_STEREO | CM_CFMT_16BIT) << CM_CFMT_ADCSHIFT);
		if ((minor & 0xf) == SND_DEV_DSP16)
			fmts |= CM_CFMT_16BIT << CM_CFMT_ADCSHIFT;
		s->dma_adc.ossfragshift = s->dma_adc.ossmaxfrags = s->dma_adc.subdivision = 0;
		set_adc_rate(s, 8000);
	}
	if (file->f_mode & FMODE_WRITE) {
		fmtm &= ~((CM_CFMT_STEREO | CM_CFMT_16BIT) << CM_CFMT_DACSHIFT);
		if ((minor & 0xf) == SND_DEV_DSP16)
			fmts |= CM_CFMT_16BIT << CM_CFMT_DACSHIFT;
		s->dma_dac.ossfragshift = s->dma_dac.ossmaxfrags = s->dma_dac.subdivision = 0;
		set_dac_rate(s, 8000);
	}
	set_fmt(s, fmtm, fmts);
	s->open_mode |= file->f_mode & (FMODE_READ | FMODE_WRITE);
	up(&s->open_sem);
	return 0;
}

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

	VALIDATE_STATE(s);
	lock_kernel();
	if (file->f_mode & FMODE_WRITE)
		drain_dac(s, file->f_flags & O_NONBLOCK);
	down(&s->open_sem);
	if (file->f_mode & FMODE_WRITE) {
		stop_dac(s);
		dealloc_dmabuf(&s->dma_dac);
	}
	if (file->f_mode & FMODE_READ) {
		stop_adc(s);
		dealloc_dmabuf(&s->dma_adc);
	}
	s->open_mode &= (~file->f_mode) & (FMODE_READ|FMODE_WRITE);
	up(&s->open_sem);
	wake_up(&s->open_wait);
	unlock_kernel();
	return 0;
}