audio.c

Usb1.1驱动c语言源代码

			if (!p)
				return -ENOMEM;
			db->sgbuf[nr] = p;
			mem_map_reserve(MAP_NR(p));
		}
		memset(db->sgbuf[nr], AFMT_ISUNSIGNED(db->format) ? 0x80 : 0, PAGE_SIZE);
		if ((nr << PAGE_SHIFT) >= db->dmasize)
			break;
	}
	db->bufsize = nr << PAGE_SHIFT;
	db->ready = 1;
	printk(KERN_DEBUG "dmabuf_init: bytepersec %d bufs %d ossfragshift %d ossmaxfrags %d "
	       "fragshift %d fragsize %d numfrag %d dmasize %d bufsize %d\n",
	       bytepersec, bufs, db->ossfragshift, db->ossmaxfrags, db->fragshift, db->fragsize,
	       db->numfrag, db->dmasize, db->bufsize);
	return 0;
}

static int dmabuf_mmap(struct dmabuf *db, unsigned long start, unsigned long size, pgprot_t prot)
{
	unsigned int nr;

	if (!db->ready || db->mapped || (start | size) & (PAGE_SIZE-1) || size > db->bufsize)
		return -EINVAL;
	size >>= PAGE_SHIFT;
	for(nr = 0; nr < size; nr++)
		if (!db->sgbuf[nr])
			return -EINVAL;
	db->mapped = 1;
	for(nr = 0; nr < size; nr++) {
		if (remap_page_range(start, virt_to_phys(db->sgbuf[nr]), PAGE_SIZE, prot))
			return -EAGAIN;
		start += PAGE_SIZE;
	}
	return 0;
}

static void dmabuf_copyin(struct dmabuf *db, const void *buffer, unsigned int size)
{
	unsigned int pgrem, rem;

	db->total_bytes += size;
	for (;;) {
		if (size <= 0)
			return;
		pgrem = ((~db->wrptr) & (PAGE_SIZE-1)) + 1;
		if (pgrem > size)
			pgrem = size;
		rem = db->dmasize - db->wrptr;
		if (pgrem > rem)
			pgrem = rem;
		memcpy((db->sgbuf[db->wrptr >> PAGE_SHIFT]) + (db->wrptr & (PAGE_SIZE-1)), buffer, pgrem);
		size -= pgrem;
		(char *)buffer += pgrem;
		db->wrptr += pgrem;
		if (db->wrptr >= db->dmasize)
			db->wrptr = 0;
	}
}

static void dmabuf_copyout(struct dmabuf *db, void *buffer, unsigned int size)
{
	unsigned int pgrem, rem;

	db->total_bytes += size;
	for (;;) {
		if (size <= 0)
			return;
		pgrem = ((~db->rdptr) & (PAGE_SIZE-1)) + 1;
		if (pgrem > size)
			pgrem = size;
		rem = db->dmasize - db->rdptr;
		if (pgrem > rem)
			pgrem = rem;
		memcpy(buffer, (db->sgbuf[db->rdptr >> PAGE_SHIFT]) + (db->rdptr & (PAGE_SIZE-1)), pgrem);
		size -= pgrem;
		(char *)buffer += pgrem;
		db->rdptr += pgrem;
		if (db->rdptr >= db->dmasize)
			db->rdptr = 0;
	}
}

static int dmabuf_copyin_user(struct dmabuf *db, unsigned int ptr, const void *buffer, unsigned int size)
{
	unsigned int pgrem, rem;

	if (!db->ready || db->mapped)
		return -EINVAL;
	for (;;) {
		if (size <= 0)
			return 0;
		pgrem = ((~ptr) & (PAGE_SIZE-1)) + 1;
		if (pgrem > size)
			pgrem = size;
		rem = db->dmasize - ptr;
		if (pgrem > rem)
			pgrem = rem;
		copy_from_user_ret((db->sgbuf[ptr >> PAGE_SHIFT]) + (ptr & (PAGE_SIZE-1)), buffer, pgrem, -EFAULT);
		size -= pgrem;
		(char *)buffer += pgrem;
		ptr += pgrem;
		if (ptr >= db->dmasize)
			ptr = 0;
	}
}

static int dmabuf_copyout_user(struct dmabuf *db, unsigned int ptr, void *buffer, unsigned int size)
{
	unsigned int pgrem, rem;

	if (!db->ready || db->mapped)
		return -EINVAL;
	for (;;) {
		if (size <= 0)
			return 0;
		pgrem = ((~ptr) & (PAGE_SIZE-1)) + 1;
		if (pgrem > size)
			pgrem = size;
		rem = db->dmasize - ptr;
		if (pgrem > rem)
			pgrem = rem;
		copy_to_user_ret(buffer, (db->sgbuf[ptr >> PAGE_SHIFT]) + (ptr & (PAGE_SIZE-1)), pgrem, -EFAULT);
		size -= pgrem;
		(char *)buffer += pgrem;
		ptr += pgrem;
		if (ptr >= db->dmasize)
			ptr = 0;
	}
}

/* --------------------------------------------------------------------- */
/*
 * USB I/O code. We do sample format conversion if necessary
 */

static void usbin_stop(struct usb_audiodev *as)
{
	struct usbin *u = &as->usbin;
	unsigned long flags;
	unsigned int i, notkilled = 1;

	spin_lock_irqsave(&as->lock, flags);
	u->flags &= ~FLG_RUNNING;
	i = u->flags;
	spin_unlock_irqrestore(&as->lock, flags);
	while (i & (FLG_URB0RUNNING|FLG_URB1RUNNING|FLG_SYNC0RUNNING|FLG_SYNC1RUNNING)) {
		set_current_state(notkilled ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
		schedule_timeout(1);
		spin_lock_irqsave(&as->lock, flags);
		i = u->flags;
		spin_unlock_irqrestore(&as->lock, flags);
		if (notkilled && signal_pending(current)) {
			if (i & FLG_URB0RUNNING)
				usb_unlink_urb(&u->durb[0].urb);
			if (i & FLG_URB1RUNNING)
				usb_unlink_urb(&u->durb[1].urb);
			if (i & FLG_SYNC0RUNNING)
				usb_unlink_urb(&u->surb[0].urb);
			if (i & FLG_SYNC1RUNNING)
				usb_unlink_urb(&u->surb[1].urb);
			notkilled = 0;
		}
	}
	set_current_state(TASK_RUNNING);
	if (u->durb[0].urb.transfer_buffer)
		kfree(u->durb[0].urb.transfer_buffer);
	if (u->durb[1].urb.transfer_buffer)
		kfree(u->durb[1].urb.transfer_buffer);
	if (u->surb[0].urb.transfer_buffer)
		kfree(u->surb[0].urb.transfer_buffer);
	if (u->surb[1].urb.transfer_buffer)
		kfree(u->surb[1].urb.transfer_buffer);
	u->durb[0].urb.transfer_buffer = u->durb[1].urb.transfer_buffer = 
		u->surb[0].urb.transfer_buffer = u->surb[1].urb.transfer_buffer = NULL;
}

static inline void usbin_release(struct usb_audiodev *as)
{
	usbin_stop(as);
}

static void usbin_disc(struct usb_audiodev *as)
{
	struct usbin *u = &as->usbin;

	unsigned long flags;

	spin_lock_irqsave(&as->lock, flags);
	u->flags &= ~(FLG_RUNNING | FLG_CONNECTED);
	spin_unlock_irqrestore(&as->lock, flags);
	usbin_stop(as);
}

static void conversion(const void *ibuf, unsigned int ifmt, void *obuf, unsigned int ofmt, void *tmp, unsigned int scnt)
{
	unsigned int cnt, i;
	__s16 *sp, *sp2, s;
	unsigned char *bp;

	cnt = scnt;
	if (AFMT_ISSTEREO(ifmt))
		cnt <<= 1;
	sp = ((__s16 *)tmp) + cnt;
	switch (ifmt & ~AFMT_STEREO) {
	case AFMT_U8:
		for (bp = ((unsigned char *)ibuf)+cnt, i = 0; i < cnt; i++) {
			bp--;
			sp--;
			*sp = (*bp ^ 0x80) << 8;
		}
		break;
			
	case AFMT_S8:
		for (bp = ((unsigned char *)ibuf)+cnt, i = 0; i < cnt; i++) {
			bp--;
			sp--;
			*sp = *bp << 8;
		}
		break;
		
	case AFMT_U16_LE:
		for (bp = ((unsigned char *)ibuf)+2*cnt, i = 0; i < cnt; i++) {
			bp -= 2;
			sp--;
			*sp = (bp[0] | (bp[1] << 8)) ^ 0x8000;
		}
		break;

	case AFMT_U16_BE:
		for (bp = ((unsigned char *)ibuf)+2*cnt, i = 0; i < cnt; i++) {
			bp -= 2;
			sp--;
			*sp = (bp[1] | (bp[0] << 8)) ^ 0x8000;
		}
		break;

	case AFMT_S16_LE:
		for (bp = ((unsigned char *)ibuf)+2*cnt, i = 0; i < cnt; i++) {
			bp -= 2;
			sp--;
			*sp = bp[0] | (bp[1] << 8);
		}
		break;

	case AFMT_S16_BE:
		for (bp = ((unsigned char *)ibuf)+2*cnt, i = 0; i < cnt; i++) {
			bp -= 2;
			sp--;
			*sp = bp[1] | (bp[0] << 8);
		}
		break;
	}
	if (!AFMT_ISSTEREO(ifmt) && AFMT_ISSTEREO(ofmt)) {
		/* expand from mono to stereo */
		for (sp = ((__s16 *)tmp)+scnt, sp2 = ((__s16 *)tmp)+2*scnt, i = 0; i < scnt; i++) {
			sp--;
			sp2 -= 2;
			sp2[0] = sp2[1] = sp[0];
		}
	}
	if (AFMT_ISSTEREO(ifmt) && !AFMT_ISSTEREO(ofmt)) {
		/* contract from stereo to mono */
		for (sp = sp2 = ((__s16 *)tmp), i = 0; i < scnt; i++, sp++, sp2 += 2)
			sp[0] = (sp2[0] + sp2[1]) >> 1;
	}
	cnt = scnt;
	if (AFMT_ISSTEREO(ofmt))
		cnt <<= 1;
	sp = ((__s16 *)tmp);
	bp = ((unsigned char *)obuf);
	switch (ofmt & ~AFMT_STEREO) {
	case AFMT_U8:
		for (i = 0; i < cnt; i++, sp++, bp++)
			*bp = (*sp >> 8) ^ 0x80;
		break;

	case AFMT_S8:
		for (i = 0; i < cnt; i++, sp++, bp++)
			*bp = *sp >> 8;
		break;

	case AFMT_U16_LE:
		for (i = 0; i < cnt; i++, sp++, bp += 2) {
			s = *sp;
			bp[0] = s;
			bp[1] = (s >> 8) ^ 0x80;
		}
		break;

	case AFMT_U16_BE:
		for (i = 0; i < cnt; i++, sp++, bp += 2) {
			s = *sp;
			bp[1] = s;
			bp[0] = (s >> 8) ^ 0x80;
		}
		break;

	case AFMT_S16_LE:
		for (i = 0; i < cnt; i++, sp++, bp += 2) {
			s = *sp;
			bp[0] = s;
			bp[1] = s >> 8;
		}
		break;

	case AFMT_S16_BE:
		for (i = 0; i < cnt; i++, sp++, bp += 2) {
			s = *sp;
			bp[1] = s;
			bp[0] = s >> 8;
		}
		break;
	}
	
}

static void usbin_convert(struct usbin *u, unsigned char *buffer, unsigned int samples)
{
	union {
		__s16 s[64];
		unsigned char b[0];
	} tmp;
	unsigned int scnt, maxs, ufmtsh, dfmtsh;

	ufmtsh = AFMT_BYTESSHIFT(u->format);
	dfmtsh = AFMT_BYTESSHIFT(u->dma.format);
	maxs = (AFMT_ISSTEREO(u->dma.format | u->format)) ? 32 : 64;
	while (samples > 0) {
		scnt = samples;
		if (scnt > maxs)
			scnt = maxs;
		conversion(buffer, u->format, tmp.b, u->dma.format, tmp.b, scnt);
		dmabuf_copyin(&u->dma, tmp.b, scnt << dfmtsh);
		buffer += scnt << ufmtsh;
		samples -= scnt;
	}
}		

static int usbin_prepare_desc(struct usbin *u, purb_t urb)
{
	unsigned int i, maxsize, offs;

	maxsize = (u->freqmax + 0x3fff) >> (14 - AFMT_BYTESSHIFT(u->format));
	//printk(KERN_DEBUG "usbin_prepare_desc: maxsize %d freq 0x%x format 0x%x\n", maxsize, u->freqn, u->format);
	for (i = offs = 0; i < DESCFRAMES; i++, offs += maxsize) {
		urb->iso_frame_desc[i].length = maxsize;
		urb->iso_frame_desc[i].offset = offs;
	}
	return 0;
}

/*
 * return value: 0 if descriptor should be restarted, -1 otherwise
 * convert sample format on the fly if necessary
 */
static int usbin_retire_desc(struct usbin *u, purb_t urb)
{
	unsigned int i, ufmtsh, dfmtsh, err = 0, cnt, scnt, dmafree;
	unsigned char *cp;

	ufmtsh = AFMT_BYTESSHIFT(u->format);
	dfmtsh = AFMT_BYTESSHIFT(u->dma.format);
	for (i = 0; i < DESCFRAMES; i++) {
		cp = ((unsigned char *)urb->transfer_buffer) + urb->iso_frame_desc[i].offset;
		if (urb->iso_frame_desc[i].status) {
			printk(KERN_DEBUG "usbin_retire_desc: frame %u status %d\n", i, urb->iso_frame_desc[i].status);
			continue;
		}
		scnt = urb->iso_frame_desc[i].actual_length >> ufmtsh;
		if (!scnt)
			continue;
		cnt = scnt << dfmtsh;
		if (!u->dma.mapped) {
			dmafree = u->dma.dmasize - u->dma.count;
			if (cnt > dmafree) {
				scnt = dmafree >> dfmtsh;
				cnt = scnt << dfmtsh;
				err++;
			}
		}
		u->dma.count += cnt;
		if (u->format == u->dma.format) {
			/* we do not need format conversion */
			dmabuf_copyin(&u->dma, cp, cnt);
		} else {
			/* we need sampling format conversion */
			usbin_convert(u, cp, scnt);
		}
	}
	if (err)
		u->dma.error++;
	if (u->dma.count >= (signed)u->dma.fragsize)
		wake_up(&u->dma.wait);
	return err ? -1 : 0;
}

static void usbin_completed(struct urb *urb)
{
	struct usb_audiodev *as = (struct usb_audiodev *)urb->context;
	struct usbin *u = &as->usbin;
	unsigned long flags;
	unsigned int mask;
	int suret = USB_ST_NOERROR;

#if 0
	printk(KERN_DEBUG "usbin_completed: status %d errcnt %d flags 0x%x\n", urb->status, urb->error_count, u->flags);
#endif
	if (urb == &u->durb[0].urb)
		mask = FLG_URB0RUNNING;
	else if (urb == &u->durb[1].urb)
		mask = FLG_URB1RUNNING;
	else {
		mask = 0;
		printk(KERN_ERR "usbin_completed: panic: unknown URB\n");
	}
	spin_lock_irqsave(&as->lock, flags);
	if (!usbin_retire_desc(u, urb) &&
	    u->flags & FLG_RUNNING &&
	    !usbin_prepare_desc(u, urb) && 
	    (suret = usb_submit_urb(urb)) == USB_ST_NOERROR) {
		u->flags |= mask;
	} else {
		u->flags &= ~(mask | FLG_RUNNING);
		wake_up(&u->dma.wait);
		printk(KERN_DEBUG "usbin_completed: descriptor not restarted (usb_submit_urb: %d)\n", suret);
	}
	spin_unlock_irqrestore(&as->lock, flags);
}

/*