dbri.c

linux 内核源代码

		/* Stream could be closed by the time we run. */
		if (first_td >= 0) {
			cmd = dbri_cmdlock(dbri, 2);
			*(cmd++) = DBRI_CMD(D_SDP, 0,
					    dbri->pipes[info->pipe].sdp
					    | D_SDP_P | D_SDP_EVERY | D_SDP_C);
			*(cmd++) = dbri->dma_dvma +
				   dbri_dma_off(desc, first_td);
			dbri_cmdsend(dbri, cmd, 2);

			/* Reset our admin of the pipe. */
			dbri->pipes[info->pipe].desc = first_td;
		}
	}

	info = &dbri->stream_info[DBRI_PLAY];

	if (info->pipe >= 0) {
		first_td = dbri->pipes[info->pipe].first_desc;

		dprintk(D_DESC, "xmit_descs play @ TD %d\n", first_td);

		/* Stream could be closed by the time we run. */
		if (first_td >= 0) {
			cmd = dbri_cmdlock(dbri, 2);
			*(cmd++) = DBRI_CMD(D_SDP, 0,
					    dbri->pipes[info->pipe].sdp
					    | D_SDP_P | D_SDP_EVERY | D_SDP_C);
			*(cmd++) = dbri->dma_dvma +
				   dbri_dma_off(desc, first_td);
			dbri_cmdsend(dbri, cmd, 2);

			/* Reset our admin of the pipe. */
			dbri->pipes[info->pipe].desc = first_td;
		}
	}

	spin_unlock_irqrestore(&dbri->lock, flags);
}

/* transmission_complete_intr()
 *
 * Called by main interrupt handler when DBRI signals transmission complete
 * on a pipe (interrupt triggered by the B bit in a transmit descriptor).
 *
 * Walks through the pipe's list of transmit buffer descriptors and marks
 * them as available. Stops when the first descriptor is found without
 * TBC (Transmit Buffer Complete) set, or we've run through them all.
 *
 * The DMA buffers are not released. They form a ring buffer and
 * they are filled by ALSA while others are transmitted by DMA.
 *
 */

static void transmission_complete_intr(struct snd_dbri *dbri, int pipe)
{
	struct dbri_streaminfo *info = &dbri->stream_info[DBRI_PLAY];
	int td = dbri->pipes[pipe].desc;
	int status;

	while (td >= 0) {
		if (td >= DBRI_NO_DESCS) {
			printk(KERN_ERR "DBRI: invalid td on pipe %d\n", pipe);
			return;
		}

		status = DBRI_TD_STATUS(dbri->dma->desc[td].word4);
		if (!(status & DBRI_TD_TBC))
			break;

		dprintk(D_INT, "TD %d, status 0x%02x\n", td, status);

		dbri->dma->desc[td].word4 = 0;	/* Reset it for next time. */
		info->offset += DBRI_RD_CNT(dbri->dma->desc[td].word1);

		td = dbri->next_desc[td];
		dbri->pipes[pipe].desc = td;
	}

	/* Notify ALSA */
	spin_unlock(&dbri->lock);
	snd_pcm_period_elapsed(info->substream);
	spin_lock(&dbri->lock);
}

static void reception_complete_intr(struct snd_dbri *dbri, int pipe)
{
	struct dbri_streaminfo *info;
	int rd = dbri->pipes[pipe].desc;
	s32 status;

	if (rd < 0 || rd >= DBRI_NO_DESCS) {
		printk(KERN_ERR "DBRI: invalid rd on pipe %d\n", pipe);
		return;
	}

	dbri->pipes[pipe].desc = dbri->next_desc[rd];
	status = dbri->dma->desc[rd].word1;
	dbri->dma->desc[rd].word1 = 0;	/* Reset it for next time. */

	info = &dbri->stream_info[DBRI_REC];
	info->offset += DBRI_RD_CNT(status);

	/* FIXME: Check status */

	dprintk(D_INT, "Recv RD %d, status 0x%02x, len %d\n",
		rd, DBRI_RD_STATUS(status), DBRI_RD_CNT(status));

	/* Notify ALSA */
	spin_unlock(&dbri->lock);
	snd_pcm_period_elapsed(info->substream);
	spin_lock(&dbri->lock);
}

static void dbri_process_one_interrupt(struct snd_dbri *dbri, int x)
{
	int val = D_INTR_GETVAL(x);
	int channel = D_INTR_GETCHAN(x);
	int command = D_INTR_GETCMD(x);
	int code = D_INTR_GETCODE(x);
#ifdef DBRI_DEBUG
	int rval = D_INTR_GETRVAL(x);
#endif

	if (channel == D_INTR_CMD) {
		dprintk(D_CMD, "INTR: Command: %-5s  Value:%d\n",
			cmds[command], val);
	} else {
		dprintk(D_INT, "INTR: Chan:%d Code:%d Val:%#x\n",
			channel, code, rval);
	}

	switch (code) {
	case D_INTR_CMDI:
		if (command != D_WAIT)
			printk(KERN_ERR "DBRI: Command read interrupt\n");
		break;
	case D_INTR_BRDY:
		reception_complete_intr(dbri, channel);
		break;
	case D_INTR_XCMP:
	case D_INTR_MINT:
		transmission_complete_intr(dbri, channel);
		break;
	case D_INTR_UNDR:
		/* UNDR - Transmission underrun
		 * resend SDP command with clear pipe bit (C) set
		 */
		{
	/* FIXME: do something useful in case of underrun */
			printk(KERN_ERR "DBRI: Underrun error\n");
#if 0
			s32 *cmd;
			int pipe = channel;
			int td = dbri->pipes[pipe].desc;

			dbri->dma->desc[td].word4 = 0;
			cmd = dbri_cmdlock(dbri, NoGetLock);
			*(cmd++) = DBRI_CMD(D_SDP, 0,
					    dbri->pipes[pipe].sdp
					    | D_SDP_P | D_SDP_C | D_SDP_2SAME);
			*(cmd++) = dbri->dma_dvma + dbri_dma_off(desc, td);
			dbri_cmdsend(dbri, cmd);
#endif
		}
		break;
	case D_INTR_FXDT:
		/* FXDT - Fixed data change */
		if (dbri->pipes[channel].sdp & D_SDP_MSB)
			val = reverse_bytes(val, dbri->pipes[channel].length);

		if (dbri->pipes[channel].recv_fixed_ptr)
			*(dbri->pipes[channel].recv_fixed_ptr) = val;
		break;
	default:
		if (channel != D_INTR_CMD)
			printk(KERN_WARNING
			       "DBRI: Ignored Interrupt: %d (0x%x)\n", code, x);
	}
}

/* dbri_process_interrupt_buffer advances through the DBRI's interrupt
 * buffer until it finds a zero word (indicating nothing more to do
 * right now).  Non-zero words require processing and are handed off
 * to dbri_process_one_interrupt AFTER advancing the pointer.
 */
static void dbri_process_interrupt_buffer(struct snd_dbri *dbri)
{
	s32 x;

	while ((x = dbri->dma->intr[dbri->dbri_irqp]) != 0) {
		dbri->dma->intr[dbri->dbri_irqp] = 0;
		dbri->dbri_irqp++;
		if (dbri->dbri_irqp == DBRI_INT_BLK)
			dbri->dbri_irqp = 1;

		dbri_process_one_interrupt(dbri, x);
	}
}

static irqreturn_t snd_dbri_interrupt(int irq, void *dev_id)
{
	struct snd_dbri *dbri = dev_id;
	static int errcnt = 0;
	int x;

	if (dbri == NULL)
		return IRQ_NONE;
	spin_lock(&dbri->lock);

	/*
	 * Read it, so the interrupt goes away.
	 */
	x = sbus_readl(dbri->regs + REG1);

	if (x & (D_MRR | D_MLE | D_LBG | D_MBE)) {
		u32 tmp;

		if (x & D_MRR)
			printk(KERN_ERR
			       "DBRI: Multiple Error Ack on SBus reg1=0x%x\n",
			       x);
		if (x & D_MLE)
			printk(KERN_ERR
			       "DBRI: Multiple Late Error on SBus reg1=0x%x\n",
			       x);
		if (x & D_LBG)
			printk(KERN_ERR
			       "DBRI: Lost Bus Grant on SBus reg1=0x%x\n", x);
		if (x & D_MBE)
			printk(KERN_ERR
			       "DBRI: Burst Error on SBus reg1=0x%x\n", x);

		/* Some of these SBus errors cause the chip's SBus circuitry
		 * to be disabled, so just re-enable and try to keep going.
		 *
		 * The only one I've seen is MRR, which will be triggered
		 * if you let a transmit pipe underrun, then try to CDP it.
		 *
		 * If these things persist, we reset the chip.
		 */
		if ((++errcnt) % 10 == 0) {
			dprintk(D_INT, "Interrupt errors exceeded.\n");
			dbri_reset(dbri);
		} else {
			tmp = sbus_readl(dbri->regs + REG0);
			tmp &= ~(D_D);
			sbus_writel(tmp, dbri->regs + REG0);
		}
	}

	dbri_process_interrupt_buffer(dbri);

	spin_unlock(&dbri->lock);

	return IRQ_HANDLED;
}

/****************************************************************************
		PCM Interface
****************************************************************************/
static struct snd_pcm_hardware snd_dbri_pcm_hw = {
	.info		= SNDRV_PCM_INFO_MMAP |
			  SNDRV_PCM_INFO_INTERLEAVED |
			  SNDRV_PCM_INFO_BLOCK_TRANSFER |
			  SNDRV_PCM_INFO_MMAP_VALID,
	.formats	= SNDRV_PCM_FMTBIT_MU_LAW |
			  SNDRV_PCM_FMTBIT_A_LAW |
			  SNDRV_PCM_FMTBIT_U8 |
			  SNDRV_PCM_FMTBIT_S16_BE,
	.rates		= SNDRV_PCM_RATE_8000_48000 | SNDRV_PCM_RATE_5512,
	.rate_min		= 5512,
	.rate_max		= 48000,
	.channels_min		= 1,
	.channels_max		= 2,
	.buffer_bytes_max	= 64 * 1024,
	.period_bytes_min	= 1,
	.period_bytes_max	= DBRI_TD_MAXCNT,
	.periods_min		= 1,
	.periods_max		= 1024,
};

static int snd_hw_rule_format(struct snd_pcm_hw_params *params,
			      struct snd_pcm_hw_rule *rule)
{
	struct snd_interval *c = hw_param_interval(params,
				SNDRV_PCM_HW_PARAM_CHANNELS);
	struct snd_mask *f = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
	struct snd_mask fmt;

	snd_mask_any(&fmt);
	if (c->min > 1) {
		fmt.bits[0] &= SNDRV_PCM_FMTBIT_S16_BE;
		return snd_mask_refine(f, &fmt);
	}
	return 0;
}

static int snd_hw_rule_channels(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	struct snd_interval *c = hw_param_interval(params,
				SNDRV_PCM_HW_PARAM_CHANNELS);
	struct snd_mask *f = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
	struct snd_interval ch;

	snd_interval_any(&ch);
	if (!(f->bits[0] & SNDRV_PCM_FMTBIT_S16_BE)) {
		ch.min = 1;
		ch.max = 1;
		ch.integer = 1;
		return snd_interval_refine(c, &ch);
	}
	return 0;
}

static int snd_dbri_open(struct snd_pcm_substream *substream)
{
	struct snd_dbri *dbri = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct dbri_streaminfo *info = DBRI_STREAM(dbri, substream);
	unsigned long flags;

	dprintk(D_USR, "open audio output.\n");
	runtime->hw = snd_dbri_pcm_hw;

	spin_lock_irqsave(&dbri->lock, flags);
	info->substream = substream;
	info->offset = 0;
	info->dvma_buffer = 0;
	info->pipe = -1;
	spin_unlock_irqrestore(&dbri->lock, flags);

	snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
			    snd_hw_rule_format, NULL, SNDRV_PCM_HW_PARAM_FORMAT,
			    -1);
	snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
			    snd_hw_rule_channels, NULL,
			    SNDRV_PCM_HW_PARAM_CHANNELS,
			    -1);

	cs4215_open(dbri);

	return 0;
}

static int snd_dbri_close(struct snd_pcm_substream *substream)
{
	struct snd_dbri *dbri = snd_pcm_substream_chip(substream);
	struct dbri_streaminfo *info = DBRI_STREAM(dbri, substream);

	dprintk(D_USR, "close audio output.\n");
	info->substream = NULL;
	info->offset = 0;

	return 0;
}

static int snd_dbri_hw_params(struct snd_pcm_substream *substream,
			      struct snd_pcm_hw_params *hw_params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_dbri *dbri = snd_pcm_substream_chip(substream);
	struct dbri_streaminfo *info = DBRI_STREAM(dbri, substream);
	int direction;
	int ret;

	/* set sampling rate, audio format and number of channels */
	ret = cs4215_prepare(dbri, params_rate(hw_params),
			     params_format(hw_params),
			     params_channels(hw_params));
	if (ret != 0)
		return ret;

	if ((ret = snd_pcm_lib_malloc_pages(substream,
				params_buffer_bytes(hw_params))) < 0) {
		printk(KERN_ERR "malloc_pages failed with %d\n", ret);
		return ret;
	}

	/* hw_params can get called multiple times. Only map the DMA once.
	 */
	if (info->dvma_buffer == 0) {
		if (DBRI_STREAMNO(substream) == DBRI_PLAY)
			direction = SBUS_DMA_TODEVICE;
		else
			direction = SBUS_DMA_FROMDEVICE;

		info->dvma_buffer = sbus_map_single(dbri->sdev,
					runtime->dma_area,
					params_buffer_bytes(hw_params),
					direction);
	}

	direction = params_buffer_bytes(hw_params);
	dprintk(D_USR, "hw_params: %d bytes, dvma=%x\n",
		direction, info->dvma_buffer);
	return 0;
}

static int snd_dbri_hw_free(struct snd_pcm_substream *substream)
{
	struct snd_dbri *dbri = snd_pcm_substream_chip(substream);
	struct dbri_streaminfo *info = DBRI_STREAM(dbri, substream);
	int direction;

	dprintk(D_USR, "hw_free.\n");

	/* hw_free can get called multiple times. Only unmap the DMA once.
	 */
	if (info->dvma_buffer) {
		if (DBRI_STREAMNO(substream) == DBRI_PLAY)
			direction = SBUS_DMA_TODEVICE;
		else
			direction = SBUS_DMA_FROMDEVICE;

		sbus_unmap_single(dbri->sdev, info->dvma_buffer,
				  substream->runtime->buffer_size, direction);
		info->dvma_buffer = 0;
	}
	if (info->pipe != -1) {
		reset_pipe(dbri, info->pipe);
		info->pipe = -1;
	}