dbri.c

linux 内核源代码

	}

	if ((sdp & 0xf800) != sdp) {
		printk(KERN_ERR "DBRI: setup_pipe called "
			"with strange SDP value\n");
		/* sdp &= 0xf800; */
	}

	/* If this is a fixed receive pipe, arrange for an interrupt
	 * every time its data changes
	 */
	if (D_SDP_MODE(sdp) == D_SDP_FIXED && !(sdp & D_SDP_TO_SER))
		sdp |= D_SDP_CHANGE;

	sdp |= D_PIPE(pipe);
	dbri->pipes[pipe].sdp = sdp;
	dbri->pipes[pipe].desc = -1;
	dbri->pipes[pipe].first_desc = -1;

	reset_pipe(dbri, pipe);
}

/*
 * Lock must be held before calling this.
 */
static void link_time_slot(struct snd_dbri *dbri, int pipe,
			   int prevpipe, int nextpipe,
			   int length, int cycle)
{
	s32 *cmd;
	int val;

	if (pipe < 0 || pipe > DBRI_MAX_PIPE
			|| prevpipe < 0 || prevpipe > DBRI_MAX_PIPE
			|| nextpipe < 0 || nextpipe > DBRI_MAX_PIPE) {
		printk(KERN_ERR
		    "DBRI: link_time_slot called with illegal pipe number\n");
		return;
	}

	if (dbri->pipes[pipe].sdp == 0
			|| dbri->pipes[prevpipe].sdp == 0
			|| dbri->pipes[nextpipe].sdp == 0) {
		printk(KERN_ERR "DBRI: link_time_slot called "
			"on uninitialized pipe\n");
		return;
	}

	dbri->pipes[prevpipe].nextpipe = pipe;
	dbri->pipes[pipe].nextpipe = nextpipe;
	dbri->pipes[pipe].length = length;

	cmd = dbri_cmdlock(dbri, 4);

	if (dbri->pipes[pipe].sdp & D_SDP_TO_SER) {
		/* Deal with CHI special case:
		 * "If transmission on edges 0 or 1 is desired, then cycle n
		 *  (where n = # of bit times per frame...) must be used."
		 *                  - DBRI data sheet, page 11
		 */
		if (prevpipe == 16 && cycle == 0)
			cycle = dbri->chi_bpf;

		val = D_DTS_VO | D_DTS_INS | D_DTS_PRVOUT(prevpipe) | pipe;
		*(cmd++) = DBRI_CMD(D_DTS, 0, val);
		*(cmd++) = 0;
		*(cmd++) =
		    D_TS_LEN(length) | D_TS_CYCLE(cycle) | D_TS_NEXT(nextpipe);
	} else {
		val = D_DTS_VI | D_DTS_INS | D_DTS_PRVIN(prevpipe) | pipe;
		*(cmd++) = DBRI_CMD(D_DTS, 0, val);
		*(cmd++) =
		    D_TS_LEN(length) | D_TS_CYCLE(cycle) | D_TS_NEXT(nextpipe);
		*(cmd++) = 0;
	}
	*(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

	dbri_cmdsend(dbri, cmd, 4);
}

#if 0
/*
 * Lock must be held before calling this.
 */
static void unlink_time_slot(struct snd_dbri *dbri, int pipe,
			     enum in_or_out direction, int prevpipe,
			     int nextpipe)
{
	s32 *cmd;
	int val;

	if (pipe < 0 || pipe > DBRI_MAX_PIPE
			|| prevpipe < 0 || prevpipe > DBRI_MAX_PIPE
			|| nextpipe < 0 || nextpipe > DBRI_MAX_PIPE) {
		printk(KERN_ERR
		    "DBRI: unlink_time_slot called with illegal pipe number\n");
		return;
	}

	cmd = dbri_cmdlock(dbri, 4);

	if (direction == PIPEinput) {
		val = D_DTS_VI | D_DTS_DEL | D_DTS_PRVIN(prevpipe) | pipe;
		*(cmd++) = DBRI_CMD(D_DTS, 0, val);
		*(cmd++) = D_TS_NEXT(nextpipe);
		*(cmd++) = 0;
	} else {
		val = D_DTS_VO | D_DTS_DEL | D_DTS_PRVOUT(prevpipe) | pipe;
		*(cmd++) = DBRI_CMD(D_DTS, 0, val);
		*(cmd++) = 0;
		*(cmd++) = D_TS_NEXT(nextpipe);
	}
	*(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

	dbri_cmdsend(dbri, cmd, 4);
}
#endif

/* xmit_fixed() / recv_fixed()
 *
 * Transmit/receive data on a "fixed" pipe - i.e, one whose contents are not
 * expected to change much, and which we don't need to buffer.
 * The DBRI only interrupts us when the data changes (receive pipes),
 * or only changes the data when this function is called (transmit pipes).
 * Only short pipes (numbers 16-31) can be used in fixed data mode.
 *
 * These function operate on a 32-bit field, no matter how large
 * the actual time slot is.  The interrupt handler takes care of bit
 * ordering and alignment.  An 8-bit time slot will always end up
 * in the low-order 8 bits, filled either MSB-first or LSB-first,
 * depending on the settings passed to setup_pipe().
 *
 * Lock must not be held before calling it.
 */
static void xmit_fixed(struct snd_dbri *dbri, int pipe, unsigned int data)
{
	s32 *cmd;
	unsigned long flags;

	if (pipe < 16 || pipe > DBRI_MAX_PIPE) {
		printk(KERN_ERR "DBRI: xmit_fixed: Illegal pipe number\n");
		return;
	}

	if (D_SDP_MODE(dbri->pipes[pipe].sdp) == 0) {
		printk(KERN_ERR "DBRI: xmit_fixed: "
			"Uninitialized pipe %d\n", pipe);
		return;
	}

	if (D_SDP_MODE(dbri->pipes[pipe].sdp) != D_SDP_FIXED) {
		printk(KERN_ERR "DBRI: xmit_fixed: Non-fixed pipe %d\n", pipe);
		return;
	}

	if (!(dbri->pipes[pipe].sdp & D_SDP_TO_SER)) {
		printk(KERN_ERR "DBRI: xmit_fixed: Called on receive pipe %d\n",
			pipe);
		return;
	}

	/* DBRI short pipes always transmit LSB first */

	if (dbri->pipes[pipe].sdp & D_SDP_MSB)
		data = reverse_bytes(data, dbri->pipes[pipe].length);

	cmd = dbri_cmdlock(dbri, 3);

	*(cmd++) = DBRI_CMD(D_SSP, 0, pipe);
	*(cmd++) = data;
	*(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

	spin_lock_irqsave(&dbri->lock, flags);
	dbri_cmdsend(dbri, cmd, 3);
	spin_unlock_irqrestore(&dbri->lock, flags);
	dbri_cmdwait(dbri);

}

static void recv_fixed(struct snd_dbri *dbri, int pipe, volatile __u32 *ptr)
{
	if (pipe < 16 || pipe > DBRI_MAX_PIPE) {
		printk(KERN_ERR "DBRI: recv_fixed called with "
			"illegal pipe number\n");
		return;
	}

	if (D_SDP_MODE(dbri->pipes[pipe].sdp) != D_SDP_FIXED) {
		printk(KERN_ERR "DBRI: recv_fixed called on "
			"non-fixed pipe %d\n", pipe);
		return;
	}

	if (dbri->pipes[pipe].sdp & D_SDP_TO_SER) {
		printk(KERN_ERR "DBRI: recv_fixed called on "
			"transmit pipe %d\n", pipe);
		return;
	}

	dbri->pipes[pipe].recv_fixed_ptr = ptr;
}

/* setup_descs()
 *
 * Setup transmit/receive data on a "long" pipe - i.e, one associated
 * with a DMA buffer.
 *
 * Only pipe numbers 0-15 can be used in this mode.
 *
 * This function takes a stream number pointing to a data buffer,
 * and work by building chains of descriptors which identify the
 * data buffers.  Buffers too large for a single descriptor will
 * be spread across multiple descriptors.
 *
 * All descriptors create a ring buffer.
 *
 * Lock must be held before calling this.
 */
static int setup_descs(struct snd_dbri *dbri, int streamno, unsigned int period)
{
	struct dbri_streaminfo *info = &dbri->stream_info[streamno];
	__u32 dvma_buffer;
	int desc;
	int len;
	int first_desc = -1;
	int last_desc = -1;

	if (info->pipe < 0 || info->pipe > 15) {
		printk(KERN_ERR "DBRI: setup_descs: Illegal pipe number\n");
		return -2;
	}

	if (dbri->pipes[info->pipe].sdp == 0) {
		printk(KERN_ERR "DBRI: setup_descs: Uninitialized pipe %d\n",
		       info->pipe);
		return -2;
	}

	dvma_buffer = info->dvma_buffer;
	len = info->size;

	if (streamno == DBRI_PLAY) {
		if (!(dbri->pipes[info->pipe].sdp & D_SDP_TO_SER)) {
			printk(KERN_ERR "DBRI: setup_descs: "
				"Called on receive pipe %d\n", info->pipe);
			return -2;
		}
	} else {
		if (dbri->pipes[info->pipe].sdp & D_SDP_TO_SER) {
			printk(KERN_ERR
			    "DBRI: setup_descs: Called on transmit pipe %d\n",
			     info->pipe);
			return -2;
		}
		/* Should be able to queue multiple buffers
		 * to receive on a pipe
		 */
		if (pipe_active(dbri, info->pipe)) {
			printk(KERN_ERR "DBRI: recv_on_pipe: "
				"Called on active pipe %d\n", info->pipe);
			return -2;
		}

		/* Make sure buffer size is multiple of four */
		len &= ~3;
	}

	/* Free descriptors if pipe has any */
	desc = dbri->pipes[info->pipe].first_desc;
	if (desc >= 0)
		do {
			dbri->dma->desc[desc].ba = 0;
			dbri->dma->desc[desc].nda = 0;
			desc = dbri->next_desc[desc];
		} while (desc != -1 &&
			 desc != dbri->pipes[info->pipe].first_desc);

	dbri->pipes[info->pipe].desc = -1;
	dbri->pipes[info->pipe].first_desc = -1;

	desc = 0;
	while (len > 0) {
		int mylen;

		for (; desc < DBRI_NO_DESCS; desc++) {
			if (!dbri->dma->desc[desc].ba)
				break;
		}

		if (desc == DBRI_NO_DESCS) {
			printk(KERN_ERR "DBRI: setup_descs: No descriptors\n");
			return -1;
		}

		if (len > DBRI_TD_MAXCNT)
			mylen = DBRI_TD_MAXCNT;	/* 8KB - 4 */
		else
			mylen = len;

		if (mylen > period)
			mylen = period;

		dbri->next_desc[desc] = -1;
		dbri->dma->desc[desc].ba = dvma_buffer;
		dbri->dma->desc[desc].nda = 0;

		if (streamno == DBRI_PLAY) {
			dbri->dma->desc[desc].word1 = DBRI_TD_CNT(mylen);
			dbri->dma->desc[desc].word4 = 0;
			dbri->dma->desc[desc].word1 |= DBRI_TD_F | DBRI_TD_B;
		} else {
			dbri->dma->desc[desc].word1 = 0;
			dbri->dma->desc[desc].word4 =
			    DBRI_RD_B | DBRI_RD_BCNT(mylen);
		}

		if (first_desc == -1)
			first_desc = desc;
		else {
			dbri->next_desc[last_desc] = desc;
			dbri->dma->desc[last_desc].nda =
			    dbri->dma_dvma + dbri_dma_off(desc, desc);
		}

		last_desc = desc;
		dvma_buffer += mylen;
		len -= mylen;
	}

	if (first_desc == -1 || last_desc == -1) {
		printk(KERN_ERR "DBRI: setup_descs: "
			" Not enough descriptors available\n");
		return -1;
	}

	dbri->dma->desc[last_desc].nda =
	    dbri->dma_dvma + dbri_dma_off(desc, first_desc);
	dbri->next_desc[last_desc] = first_desc;
	dbri->pipes[info->pipe].first_desc = first_desc;
	dbri->pipes[info->pipe].desc = first_desc;

#ifdef DBRI_DEBUG
	for (desc = first_desc; desc != -1;) {
		dprintk(D_DESC, "DESC %d: %08x %08x %08x %08x\n",
			desc,
			dbri->dma->desc[desc].word1,
			dbri->dma->desc[desc].ba,
			dbri->dma->desc[desc].nda, dbri->dma->desc[desc].word4);
			desc = dbri->next_desc[desc];
			if (desc == first_desc)
				break;
	}
#endif
	return 0;
}

/*
****************************************************************************
************************** DBRI - CHI interface ****************************
****************************************************************************

The CHI is a four-wire (clock, frame sync, data in, data out) time-division
multiplexed serial interface which the DBRI can operate in either master
(give clock/frame sync) or slave (take clock/frame sync) mode.

*/

enum master_or_slave { CHImaster, CHIslave };

/*
 * Lock must not be held before calling it.
 */
static void reset_chi(struct snd_dbri *dbri,
		      enum master_or_slave master_or_slave,
		      int bits_per_frame)
{
	s32 *cmd;
	int val;

	/* Set CHI Anchor: Pipe 16 */

	cmd = dbri_cmdlock(dbri, 4);
	val = D_DTS_VO | D_DTS_VI | D_DTS_INS
		| D_DTS_PRVIN(16) | D_PIPE(16) | D_DTS_PRVOUT(16);
	*(cmd++) = DBRI_CMD(D_DTS, 0, val);
	*(cmd++) = D_TS_ANCHOR | D_TS_NEXT(16);
	*(cmd++) = D_TS_ANCHOR | D_TS_NEXT(16);
	*(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);
	dbri_cmdsend(dbri, cmd, 4);

	dbri->pipes[16].sdp = 1;
	dbri->pipes[16].nextpipe = 16;

	cmd = dbri_cmdlock(dbri, 4);

	if (master_or_slave == CHIslave) {
		/* Setup DBRI for CHI Slave - receive clock, frame sync (FS)
		 *
		 * CHICM  = 0 (slave mode, 8 kHz frame rate)
		 * IR     = give immediate CHI status interrupt
		 * EN     = give CHI status interrupt upon change
		 */
		*(cmd++) = DBRI_CMD(D_CHI, 0, D_CHI_CHICM(0));
	} else {
		/* Setup DBRI for CHI Master - generate clock, FS
		 *
		 * BPF				=  bits per 8 kHz frame
		 * 12.288 MHz / CHICM_divisor	= clock rate
		 * FD = 1 - drive CHIFS on rising edge of CHICK
		 */
		int clockrate = bits_per_frame * 8;
		int divisor = 12288 / clockrate;

		if (divisor > 255 || divisor * clockrate != 12288)
			printk(KERN_ERR "DBRI: illegal bits_per_frame "
				"in setup_chi\n");

		*(cmd++) = DBRI_CMD(D_CHI, 0, D_CHI_CHICM(divisor) | D_CHI_FD
				    | D_CHI_BPF(bits_per_frame));
	}

	dbri->chi_bpf = bits_per_frame;

	/* CHI Data Mode
	 *
	 * RCE   =  0 - receive on falling edge of CHICK
	 * XCE   =  1 - transmit on rising edge of CHICK
	 * XEN   =  1 - enable transmitter