i2sbus-pcm.c

linux 内核源代码

/*
 * i2sbus driver -- pcm routines
 *
 * Copyright 2006 Johannes Berg <[e-mail]>
 *
 * GPL v2, can be found in COPYING.
 */

#include <asm/io.h>
#include <linux/delay.h>
/* So apparently there's a reason for requiring driver.h
 * to be included first, even if I don't know it... */
#include <sound/driver.h>
#include <sound/core.h>
#include <asm/macio.h>
#include <linux/pci.h>
#include "../soundbus.h"
#include "i2sbus.h"

static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
				struct pcm_info **pi, struct pcm_info **other)
{
	if (in) {
		if (pi)
			*pi = &i2sdev->in;
		if (other)
			*other = &i2sdev->out;
	} else {
		if (pi)
			*pi = &i2sdev->out;
		if (other)
			*other = &i2sdev->in;
	}
}

static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
{
	/* sclk must be derived from mclk! */
	if (mclk % sclk)
		return -1;
	/* derive sclk register value */
	if (i2s_sf_sclkdiv(mclk / sclk, out))
		return -1;

	if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
			*out |= I2S_SF_CLOCK_SOURCE_18MHz;
			return 0;
		}
	}
	if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
			*out |= I2S_SF_CLOCK_SOURCE_45MHz;
			return 0;
		}
	}
	if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
			*out |= I2S_SF_CLOCK_SOURCE_49MHz;
			return 0;
		}
	}
	return -1;
}

#define CHECK_RATE(rate)						\
	do { if (rates & SNDRV_PCM_RATE_ ##rate) {			\
		int dummy;						\
		if (clock_and_divisors(sysclock_factor,			\
				       bus_factor, rate, &dummy))	\
			rates &= ~SNDRV_PCM_RATE_ ##rate;		\
	} } while (0)

static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
{
	struct pcm_info *pi, *other;
	struct soundbus_dev *sdev;
	int masks_inited = 0, err;
	struct codec_info_item *cii, *rev;
	struct snd_pcm_hardware *hw;
	u64 formats = 0;
	unsigned int rates = 0;
	struct transfer_info v;
	int result = 0;
	int bus_factor = 0, sysclock_factor = 0;
	int found_this;

	mutex_lock(&i2sdev->lock);

	get_pcm_info(i2sdev, in, &pi, &other);

	hw = &pi->substream->runtime->hw;
	sdev = &i2sdev->sound;

	if (pi->active) {
		/* alsa messed up */
		result = -EBUSY;
		goto out_unlock;
	}

	/* we now need to assign the hw */
	list_for_each_entry(cii, &sdev->codec_list, list) {
		struct transfer_info *ti = cii->codec->transfers;
		bus_factor = cii->codec->bus_factor;
		sysclock_factor = cii->codec->sysclock_factor;
		while (ti->formats && ti->rates) {
			v = *ti;
			if (ti->transfer_in == in
			    && cii->codec->usable(cii, ti, &v)) {
				if (masks_inited) {
					formats &= v.formats;
					rates &= v.rates;
				} else {
					formats = v.formats;
					rates = v.rates;
					masks_inited = 1;
				}
			}
			ti++;
		}
	}
	if (!masks_inited || !bus_factor || !sysclock_factor) {
		result = -ENODEV;
		goto out_unlock;
	}
	/* bus dependent stuff */
	hw->info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
		   SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_RESUME |
		   SNDRV_PCM_INFO_JOINT_DUPLEX;

	CHECK_RATE(5512);
	CHECK_RATE(8000);
	CHECK_RATE(11025);
	CHECK_RATE(16000);
	CHECK_RATE(22050);
	CHECK_RATE(32000);
	CHECK_RATE(44100);
	CHECK_RATE(48000);
	CHECK_RATE(64000);
	CHECK_RATE(88200);
	CHECK_RATE(96000);
	CHECK_RATE(176400);
	CHECK_RATE(192000);
	hw->rates = rates;

	/* well. the codec might want 24 bits only, and we'll
	 * ever only transfer 24 bits, but they are top-aligned!
	 * So for alsa, we claim that we're doing full 32 bit
	 * while in reality we'll ignore the lower 8 bits of
	 * that when doing playback (they're transferred as 0
	 * as far as I know, no codecs we have are 32-bit capable
	 * so I can't really test) and when doing recording we'll
	 * always have those lower 8 bits recorded as 0 */
	if (formats & SNDRV_PCM_FMTBIT_S24_BE)
		formats |= SNDRV_PCM_FMTBIT_S32_BE;
	if (formats & SNDRV_PCM_FMTBIT_U24_BE)
		formats |= SNDRV_PCM_FMTBIT_U32_BE;
	/* now mask off what we can support. I suppose we could
	 * also support S24_3LE and some similar formats, but I
	 * doubt there's a codec that would be able to use that,
	 * so we don't support it here. */
	hw->formats = formats & (SNDRV_PCM_FMTBIT_S16_BE |
				 SNDRV_PCM_FMTBIT_U16_BE |
				 SNDRV_PCM_FMTBIT_S32_BE |
				 SNDRV_PCM_FMTBIT_U32_BE);

	/* we need to set the highest and lowest rate possible.
	 * These are the highest and lowest rates alsa can
	 * support properly in its bitfield.
	 * Below, we'll use that to restrict to the rate
	 * currently in use (if any). */
	hw->rate_min = 5512;
	hw->rate_max = 192000;
	/* if the other stream is active, then we can only
	 * support what it is currently using.
	 * FIXME: I lied. This comment is wrong. We can support
	 * anything that works with the same serial format, ie.
	 * when recording 24 bit sound we can well play 16 bit
	 * sound at the same time iff using the same transfer mode.
	 */
	if (other->active) {
		/* FIXME: is this guaranteed by the alsa api? */
		hw->formats &= (1ULL << i2sdev->format);
		/* see above, restrict rates to the one we already have */
		hw->rate_min = i2sdev->rate;
		hw->rate_max = i2sdev->rate;
	}

	hw->channels_min = 2;
	hw->channels_max = 2;
	/* these are somewhat arbitrary */
	hw->buffer_bytes_max = 131072;
	hw->period_bytes_min = 256;
	hw->period_bytes_max = 16384;
	hw->periods_min = 3;
	hw->periods_max = MAX_DBDMA_COMMANDS;
	list_for_each_entry(cii, &sdev->codec_list, list) {
		if (cii->codec->open) {
			err = cii->codec->open(cii, pi->substream);
			if (err) {
				result = err;
				/* unwind */
				found_this = 0;
				list_for_each_entry_reverse(rev,
				    &sdev->codec_list, list) {
					if (found_this && rev->codec->close) {
						rev->codec->close(rev,
								pi->substream);
					}
					if (rev == cii)
						found_this = 1;
				}
				goto out_unlock;
			}
		}
	}

 out_unlock:
	mutex_unlock(&i2sdev->lock);
	return result;
}

#undef CHECK_RATE

static int i2sbus_pcm_close(struct i2sbus_dev *i2sdev, int in)
{
	struct codec_info_item *cii;
	struct pcm_info *pi;
	int err = 0, tmp;

	mutex_lock(&i2sdev->lock);

	get_pcm_info(i2sdev, in, &pi, NULL);

	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
		if (cii->codec->close) {
			tmp = cii->codec->close(cii, pi->substream);
			if (tmp)
				err = tmp;
		}
	}

	pi->substream = NULL;
	pi->active = 0;
	mutex_unlock(&i2sdev->lock);
	return err;
}

static void i2sbus_wait_for_stop(struct i2sbus_dev *i2sdev,
				 struct pcm_info *pi)
{
	unsigned long flags;
	struct completion done;
	long timeout;

	spin_lock_irqsave(&i2sdev->low_lock, flags);
	if (pi->dbdma_ring.stopping) {
		init_completion(&done);
		pi->stop_completion = &done;
		spin_unlock_irqrestore(&i2sdev->low_lock, flags);
		timeout = wait_for_completion_timeout(&done, HZ);
		spin_lock_irqsave(&i2sdev->low_lock, flags);
		pi->stop_completion = NULL;
		if (timeout == 0) {
			/* timeout expired, stop dbdma forcefully */
			printk(KERN_ERR "i2sbus_wait_for_stop: timed out\n");
			/* make sure RUN, PAUSE and S0 bits are cleared */
			out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
			pi->dbdma_ring.stopping = 0;
			timeout = 10;
			while (in_le32(&pi->dbdma->status) & ACTIVE) {
				if (--timeout <= 0)
					break;
				udelay(1);
			}
		}
	}
	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
}

#ifdef CONFIG_PM
void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev)
{
	struct pcm_info *pi;

	get_pcm_info(i2sdev, 0, &pi, NULL);
	i2sbus_wait_for_stop(i2sdev, pi);
	get_pcm_info(i2sdev, 1, &pi, NULL);
	i2sbus_wait_for_stop(i2sdev, pi);
}
#endif

static int i2sbus_hw_params(struct snd_pcm_substream *substream,
			    struct snd_pcm_hw_params *params)
{
	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
}

static inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
	struct pcm_info *pi;

	get_pcm_info(i2sdev, in, &pi, NULL);
	if (pi->dbdma_ring.stopping)
		i2sbus_wait_for_stop(i2sdev, pi);
	snd_pcm_lib_free_pages(substream);
	return 0;
}

static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
{
	return i2sbus_hw_free(substream, 0);
}

static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
{
	return i2sbus_hw_free(substream, 1);
}

static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
{
	/* whee. Hard work now. The user has selected a bitrate
	 * and bit format, so now we have to program our
	 * I2S controller appropriately. */
	struct snd_pcm_runtime *runtime;
	struct dbdma_cmd *command;
	int i, periodsize, nperiods;
	dma_addr_t offset;
	struct bus_info bi;
	struct codec_info_item *cii;
	int sfr = 0;		/* serial format register */
	int dws = 0;		/* data word sizes reg */
	int input_16bit;
	struct pcm_info *pi, *other;
	int cnt;
	int result = 0;
	unsigned int cmd, stopaddr;

	mutex_lock(&i2sdev->lock);

	get_pcm_info(i2sdev, in, &pi, &other);

	if (pi->dbdma_ring.running) {
		result = -EBUSY;
		goto out_unlock;
	}
	if (pi->dbdma_ring.stopping)
		i2sbus_wait_for_stop(i2sdev, pi);

	if (!pi->substream || !pi->substream->runtime) {
		result = -EINVAL;
		goto out_unlock;
	}

	runtime = pi->substream->runtime;
	pi->active = 1;
	if (other->active &&
	    ((i2sdev->format != runtime->format)
	     || (i2sdev->rate != runtime->rate))) {
		result = -EINVAL;
		goto out_unlock;
	}

	i2sdev->format = runtime->format;
	i2sdev->rate = runtime->rate;

	periodsize = snd_pcm_lib_period_bytes(pi->substream);
	nperiods = pi->substream->runtime->periods;
	pi->current_period = 0;

	/* generate dbdma command ring first */
	command = pi->dbdma_ring.cmds;
	memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));

	/* commands to DMA to/from the ring */
	/*
	 * For input, we need to do a graceful stop; if we abort
	 * the DMA, we end up with leftover bytes that corrupt
	 * the next recording.  To do this we set the S0 status
	 * bit and wait for the DMA controller to stop.  Each
	 * command has a branch condition to
	 * make it branch to a stop command if S0 is set.
	 * On input we also need to wait for the S7 bit to be
	 * set before turning off the DMA controller.
	 * In fact we do the graceful stop for output as well.
	 */
	offset = runtime->dma_addr;
	cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
	stopaddr = pi->dbdma_ring.bus_cmd_start +
		(nperiods + 1) * sizeof(struct dbdma_cmd);
	for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
		command->command = cpu_to_le16(cmd);
		command->cmd_dep = cpu_to_le32(stopaddr);
		command->phy_addr = cpu_to_le32(offset);
		command->req_count = cpu_to_le16(periodsize);
	}

	/* branch back to beginning of ring */
	command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
	command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
	command++;

	/* set stop command */
	command->command = cpu_to_le16(DBDMA_STOP);

	/* ok, let's set the serial format and stuff */
	switch (runtime->format) {
	/* 16 bit formats */
	case SNDRV_PCM_FORMAT_S16_BE:
	case SNDRV_PCM_FORMAT_U16_BE:
		/* FIXME: if we add different bus factors we need to
		 * do more here!! */
		bi.bus_factor = 0;
		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
			bi.bus_factor = cii->codec->bus_factor;
			break;
		}
		if (!bi.bus_factor) {
			result = -ENODEV;
			goto out_unlock;
		}
		input_16bit = 1;
		break;
	case SNDRV_PCM_FORMAT_S32_BE:
	case SNDRV_PCM_FORMAT_U32_BE:
		/* force 64x bus speed, otherwise the data cannot be
		 * transferred quickly enough! */
		bi.bus_factor = 64;
		input_16bit = 0;
		break;
	default:
		result = -EINVAL;
		goto out_unlock;
	}
	/* we assume all sysclocks are the same! */
	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
		bi.sysclock_factor = cii->codec->sysclock_factor;
		break;
	}

	if (clock_and_divisors(bi.sysclock_factor,
			       bi.bus_factor,
			       runtime->rate,
			       &sfr) < 0) {
		result = -EINVAL;
		goto out_unlock;
	}
	switch (bi.bus_factor) {
	case 32:
		sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
		break;
	case 64:
		sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
		break;
	}
	/* FIXME: THIS ASSUMES MASTER ALL THE TIME */
	sfr |= I2S_SF_SCLK_MASTER;

	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
		int err = 0;
		if (cii->codec->prepare)
			err = cii->codec->prepare(cii, &bi, pi->substream);
		if (err) {
			result = err;
			goto out_unlock;
		}
	}
	/* codecs are fine with it, so set our clocks */
	if (input_16bit)
		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
			I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
	else
		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
			I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;

	/* early exit if already programmed correctly */
	/* not locking these is fine since we touch them only in this function */
	if (in_le32(&i2sdev->intfregs->serial_format) == sfr
	 && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
		goto out_unlock;

	/* let's notify the codecs about clocks going away.
	 * For now we only do mastering on the i2s cell... */
	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
		if (cii->codec->switch_clock)
			cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);

	i2sbus_control_enable(i2sdev->control, i2sdev);
	i2sbus_control_cell(i2sdev->control, i2sdev, 1);

	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);

	i2sbus_control_clock(i2sdev->control, i2sdev, 0);

	msleep(1);

	/* wait for clock stopped. This can apparently take a while... */
	cnt = 100;
	while (cnt-- &&
	    !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
		msleep(5);
	}
	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);

	/* not locking these is fine since we touch them only in this function */
	out_le32(&i2sdev->intfregs->serial_format, sfr);
	out_le32(&i2sdev->intfregs->data_word_sizes, dws);

        i2sbus_control_enable(i2sdev->control, i2sdev);
        i2sbus_control_cell(i2sdev->control, i2sdev, 1);
        i2sbus_control_clock(i2sdev->control, i2sdev, 1);
	msleep(1);

	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
		if (cii->codec->switch_clock)
			cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);

 out_unlock:
	mutex_unlock(&i2sdev->lock);
	return result;
}

#ifdef CONFIG_PM
void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
{
	i2sbus_pcm_prepare(i2sdev, 0);
	i2sbus_pcm_prepare(i2sdev, 1);