pcm_native.c

linux 内核源代码

/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <[e-mail]>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <sound/driver.h>
#include <linux/mm.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/latency.h>
#include <linux/uio.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/info.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/timer.h>
#include <sound/minors.h>
#include <asm/io.h>

/*
 *  Compatibility
 */

struct snd_pcm_hw_params_old {
	unsigned int flags;
	unsigned int masks[SNDRV_PCM_HW_PARAM_SUBFORMAT -
			   SNDRV_PCM_HW_PARAM_ACCESS + 1];
	struct snd_interval intervals[SNDRV_PCM_HW_PARAM_TICK_TIME -
					SNDRV_PCM_HW_PARAM_SAMPLE_BITS + 1];
	unsigned int rmask;
	unsigned int cmask;
	unsigned int info;
	unsigned int msbits;
	unsigned int rate_num;
	unsigned int rate_den;
	snd_pcm_uframes_t fifo_size;
	unsigned char reserved[64];
};

#ifdef CONFIG_SND_SUPPORT_OLD_API
#define SNDRV_PCM_IOCTL_HW_REFINE_OLD _IOWR('A', 0x10, struct snd_pcm_hw_params_old)
#define SNDRV_PCM_IOCTL_HW_PARAMS_OLD _IOWR('A', 0x11, struct snd_pcm_hw_params_old)

static int snd_pcm_hw_refine_old_user(struct snd_pcm_substream *substream,
				      struct snd_pcm_hw_params_old __user * _oparams);
static int snd_pcm_hw_params_old_user(struct snd_pcm_substream *substream,
				      struct snd_pcm_hw_params_old __user * _oparams);
#endif
static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream);

/*
 *
 */

DEFINE_RWLOCK(snd_pcm_link_rwlock);
EXPORT_SYMBOL(snd_pcm_link_rwlock);

static DECLARE_RWSEM(snd_pcm_link_rwsem);

static inline mm_segment_t snd_enter_user(void)
{
	mm_segment_t fs = get_fs();
	set_fs(get_ds());
	return fs;
}

static inline void snd_leave_user(mm_segment_t fs)
{
	set_fs(fs);
}



int snd_pcm_info(struct snd_pcm_substream *substream, struct snd_pcm_info *info)
{
	struct snd_pcm_runtime *runtime;
	struct snd_pcm *pcm = substream->pcm;
	struct snd_pcm_str *pstr = substream->pstr;

	snd_assert(substream != NULL, return -ENXIO);
	memset(info, 0, sizeof(*info));
	info->card = pcm->card->number;
	info->device = pcm->device;
	info->stream = substream->stream;
	info->subdevice = substream->number;
	strlcpy(info->id, pcm->id, sizeof(info->id));
	strlcpy(info->name, pcm->name, sizeof(info->name));
	info->dev_class = pcm->dev_class;
	info->dev_subclass = pcm->dev_subclass;
	info->subdevices_count = pstr->substream_count;
	info->subdevices_avail = pstr->substream_count - pstr->substream_opened;
	strlcpy(info->subname, substream->name, sizeof(info->subname));
	runtime = substream->runtime;
	/* AB: FIXME!!! This is definitely nonsense */
	if (runtime) {
		info->sync = runtime->sync;
		substream->ops->ioctl(substream, SNDRV_PCM_IOCTL1_INFO, info);
	}
	return 0;
}

int snd_pcm_info_user(struct snd_pcm_substream *substream,
		      struct snd_pcm_info __user * _info)
{
	struct snd_pcm_info *info;
	int err;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (! info)
		return -ENOMEM;
	err = snd_pcm_info(substream, info);
	if (err >= 0) {
		if (copy_to_user(_info, info, sizeof(*info)))
			err = -EFAULT;
	}
	kfree(info);
	return err;
}

#undef RULES_DEBUG

#ifdef RULES_DEBUG
#define HW_PARAM(v) [SNDRV_PCM_HW_PARAM_##v] = #v
char *snd_pcm_hw_param_names[] = {
	HW_PARAM(ACCESS),
	HW_PARAM(FORMAT),
	HW_PARAM(SUBFORMAT),
	HW_PARAM(SAMPLE_BITS),
	HW_PARAM(FRAME_BITS),
	HW_PARAM(CHANNELS),
	HW_PARAM(RATE),
	HW_PARAM(PERIOD_TIME),
	HW_PARAM(PERIOD_SIZE),
	HW_PARAM(PERIOD_BYTES),
	HW_PARAM(PERIODS),
	HW_PARAM(BUFFER_TIME),
	HW_PARAM(BUFFER_SIZE),
	HW_PARAM(BUFFER_BYTES),
	HW_PARAM(TICK_TIME),
};
#endif

int snd_pcm_hw_refine(struct snd_pcm_substream *substream, 
		      struct snd_pcm_hw_params *params)
{
	unsigned int k;
	struct snd_pcm_hardware *hw;
	struct snd_interval *i = NULL;
	struct snd_mask *m = NULL;
	struct snd_pcm_hw_constraints *constrs = &substream->runtime->hw_constraints;
	unsigned int rstamps[constrs->rules_num];
	unsigned int vstamps[SNDRV_PCM_HW_PARAM_LAST_INTERVAL + 1];
	unsigned int stamp = 2;
	int changed, again;

	params->info = 0;
	params->fifo_size = 0;
	if (params->rmask & (1 << SNDRV_PCM_HW_PARAM_SAMPLE_BITS))
		params->msbits = 0;
	if (params->rmask & (1 << SNDRV_PCM_HW_PARAM_RATE)) {
		params->rate_num = 0;
		params->rate_den = 0;
	}

	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) {
		m = hw_param_mask(params, k);
		if (snd_mask_empty(m))
			return -EINVAL;
		if (!(params->rmask & (1 << k)))
			continue;
#ifdef RULES_DEBUG
		printk("%s = ", snd_pcm_hw_param_names[k]);
		printk("%04x%04x%04x%04x -> ", m->bits[3], m->bits[2], m->bits[1], m->bits[0]);
#endif
		changed = snd_mask_refine(m, constrs_mask(constrs, k));
#ifdef RULES_DEBUG
		printk("%04x%04x%04x%04x\n", m->bits[3], m->bits[2], m->bits[1], m->bits[0]);
#endif
		if (changed)
			params->cmask |= 1 << k;
		if (changed < 0)
			return changed;
	}

	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
		i = hw_param_interval(params, k);
		if (snd_interval_empty(i))
			return -EINVAL;
		if (!(params->rmask & (1 << k)))
			continue;
#ifdef RULES_DEBUG
		printk("%s = ", snd_pcm_hw_param_names[k]);
		if (i->empty)
			printk("empty");
		else
			printk("%c%u %u%c", 
			       i->openmin ? '(' : '[', i->min,
			       i->max, i->openmax ? ')' : ']');
		printk(" -> ");
#endif
		changed = snd_interval_refine(i, constrs_interval(constrs, k));
#ifdef RULES_DEBUG
		if (i->empty)
			printk("empty\n");
		else 
			printk("%c%u %u%c\n", 
			       i->openmin ? '(' : '[', i->min,
			       i->max, i->openmax ? ')' : ']');
#endif
		if (changed)
			params->cmask |= 1 << k;
		if (changed < 0)
			return changed;
	}

	for (k = 0; k < constrs->rules_num; k++)
		rstamps[k] = 0;
	for (k = 0; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) 
		vstamps[k] = (params->rmask & (1 << k)) ? 1 : 0;
	do {
		again = 0;
		for (k = 0; k < constrs->rules_num; k++) {
			struct snd_pcm_hw_rule *r = &constrs->rules[k];
			unsigned int d;
			int doit = 0;
			if (r->cond && !(r->cond & params->flags))
				continue;
			for (d = 0; r->deps[d] >= 0; d++) {
				if (vstamps[r->deps[d]] > rstamps[k]) {
					doit = 1;
					break;
				}
			}
			if (!doit)
				continue;
#ifdef RULES_DEBUG
			printk("Rule %d [%p]: ", k, r->func);
			if (r->var >= 0) {
				printk("%s = ", snd_pcm_hw_param_names[r->var]);
				if (hw_is_mask(r->var)) {
					m = hw_param_mask(params, r->var);
					printk("%x", *m->bits);
				} else {
					i = hw_param_interval(params, r->var);
					if (i->empty)
						printk("empty");
					else
						printk("%c%u %u%c", 
						       i->openmin ? '(' : '[', i->min,
						       i->max, i->openmax ? ')' : ']');
				}
			}
#endif
			changed = r->func(params, r);
#ifdef RULES_DEBUG
			if (r->var >= 0) {
				printk(" -> ");
				if (hw_is_mask(r->var))
					printk("%x", *m->bits);
				else {
					if (i->empty)
						printk("empty");
					else
						printk("%c%u %u%c", 
						       i->openmin ? '(' : '[', i->min,
						       i->max, i->openmax ? ')' : ']');
				}
			}
			printk("\n");
#endif
			rstamps[k] = stamp;
			if (changed && r->var >= 0) {
				params->cmask |= (1 << r->var);
				vstamps[r->var] = stamp;
				again = 1;
			}
			if (changed < 0)
				return changed;
			stamp++;
		}
	} while (again);
	if (!params->msbits) {
		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
		if (snd_interval_single(i))
			params->msbits = snd_interval_value(i);
	}

	if (!params->rate_den) {
		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
		if (snd_interval_single(i)) {
			params->rate_num = snd_interval_value(i);
			params->rate_den = 1;
		}
	}

	hw = &substream->runtime->hw;
	if (!params->info)
		params->info = hw->info;
	if (!params->fifo_size)
		params->fifo_size = hw->fifo_size;
	params->rmask = 0;
	return 0;
}

EXPORT_SYMBOL(snd_pcm_hw_refine);

static int snd_pcm_hw_refine_user(struct snd_pcm_substream *substream,
				  struct snd_pcm_hw_params __user * _params)
{
	struct snd_pcm_hw_params *params;
	int err;

	params = kmalloc(sizeof(*params), GFP_KERNEL);
	if (!params) {
		err = -ENOMEM;
		goto out;
	}
	if (copy_from_user(params, _params, sizeof(*params))) {
		err = -EFAULT;
		goto out;
	}
	err = snd_pcm_hw_refine(substream, params);
	if (copy_to_user(_params, params, sizeof(*params))) {
		if (!err)
			err = -EFAULT;
	}
out:
	kfree(params);
	return err;
}

static int period_to_usecs(struct snd_pcm_runtime *runtime)
{
	int usecs;

	if (! runtime->rate)
		return -1; /* invalid */

	/* take 75% of period time as the deadline */
	usecs = (750000 / runtime->rate) * runtime->period_size;
	usecs += ((750000 % runtime->rate) * runtime->period_size) /
		runtime->rate;

	return usecs;
}

static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
			     struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime;
	int err, usecs;
	unsigned int bits;
	snd_pcm_uframes_t frames;

	snd_assert(substream != NULL, return -ENXIO);
	runtime = substream->runtime;
	snd_assert(runtime != NULL, return -ENXIO);
	snd_pcm_stream_lock_irq(substream);
	switch (runtime->status->state) {
	case SNDRV_PCM_STATE_OPEN:
	case SNDRV_PCM_STATE_SETUP:
	case SNDRV_PCM_STATE_PREPARED:
		break;
	default:
		snd_pcm_stream_unlock_irq(substream);
		return -EBADFD;
	}
	snd_pcm_stream_unlock_irq(substream);
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
	if (!substream->oss.oss)
#endif
		if (atomic_read(&substream->mmap_count))
			return -EBADFD;

	params->rmask = ~0U;
	err = snd_pcm_hw_refine(substream, params);
	if (err < 0)
		goto _error;

	err = snd_pcm_hw_params_choose(substream, params);
	if (err < 0)
		goto _error;

	if (substream->ops->hw_params != NULL) {
		err = substream->ops->hw_params(substream, params);
		if (err < 0)
			goto _error;
	}

	runtime->access = params_access(params);
	runtime->format = params_format(params);
	runtime->subformat = params_subformat(params);
	runtime->channels = params_channels(params);
	runtime->rate = params_rate(params);
	runtime->period_size = params_period_size(params);
	runtime->periods = params_periods(params);
	runtime->buffer_size = params_buffer_size(params);
	runtime->tick_time = params_tick_time(params);
	runtime->info = params->info;
	runtime->rate_num = params->rate_num;
	runtime->rate_den = params->rate_den;

	bits = snd_pcm_format_physical_width(runtime->format);
	runtime->sample_bits = bits;
	bits *= runtime->channels;
	runtime->frame_bits = bits;
	frames = 1;
	while (bits % 8 != 0) {
		bits *= 2;
		frames *= 2;
	}
	runtime->byte_align = bits / 8;
	runtime->min_align = frames;

	/* Default sw params */
	runtime->tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
	runtime->period_step = 1;
	runtime->sleep_min = 0;
	runtime->control->avail_min = runtime->period_size;
	runtime->xfer_align = runtime->period_size;
	runtime->start_threshold = 1;
	runtime->stop_threshold = runtime->buffer_size;
	runtime->silence_threshold = 0;
	runtime->silence_size = 0;
	runtime->boundary = runtime->buffer_size;
	while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size)
		runtime->boundary *= 2;

	snd_pcm_timer_resolution_change(substream);
	runtime->status->state = SNDRV_PCM_STATE_SETUP;

	remove_acceptable_latency(substream->latency_id);
	if ((usecs = period_to_usecs(runtime)) >= 0)
		set_acceptable_latency(substream->latency_id, usecs);
	return 0;
 _error:
	/* hardware might be unuseable from this time,
	   so we force application to retry to set
	   the correct hardware parameter settings */
	runtime->status->state = SNDRV_PCM_STATE_OPEN;
	if (substream->ops->hw_free != NULL)
		substream->ops->hw_free(substream);
	return err;
}

static int snd_pcm_hw_params_user(struct snd_pcm_substream *substream,
				  struct snd_pcm_hw_params __user * _params)
{
	struct snd_pcm_hw_params *params;
	int err;

	params = kmalloc(sizeof(*params), GFP_KERNEL);
	if (!params) {
		err = -ENOMEM;
		goto out;