rawmidi.c

linux 内核源代码

/*
 *  Abstract layer for MIDI v1.0 stream
 *  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 <sound/core.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/moduleparam.h>
#include <linux/delay.h>
#include <sound/rawmidi.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/minors.h>
#include <sound/initval.h>

MODULE_AUTHOR("Jaroslav Kysela <[e-mail]>");
MODULE_DESCRIPTION("Midlevel RawMidi code for ALSA.");
MODULE_LICENSE("GPL");

#ifdef CONFIG_SND_OSSEMUL
static int midi_map[SNDRV_CARDS];
static int amidi_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
module_param_array(midi_map, int, NULL, 0444);
MODULE_PARM_DESC(midi_map, "Raw MIDI device number assigned to 1st OSS device.");
module_param_array(amidi_map, int, NULL, 0444);
MODULE_PARM_DESC(amidi_map, "Raw MIDI device number assigned to 2nd OSS device.");
#endif /* CONFIG_SND_OSSEMUL */

static int snd_rawmidi_free(struct snd_rawmidi *rawmidi);
static int snd_rawmidi_dev_free(struct snd_device *device);
static int snd_rawmidi_dev_register(struct snd_device *device);
static int snd_rawmidi_dev_disconnect(struct snd_device *device);

static LIST_HEAD(snd_rawmidi_devices);
static DEFINE_MUTEX(register_mutex);

static struct snd_rawmidi *snd_rawmidi_search(struct snd_card *card, int device)
{
	struct snd_rawmidi *rawmidi;

	list_for_each_entry(rawmidi, &snd_rawmidi_devices, list)
		if (rawmidi->card == card && rawmidi->device == device)
			return rawmidi;
	return NULL;
}

static inline unsigned short snd_rawmidi_file_flags(struct file *file)
{
	switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
	case FMODE_WRITE:
		return SNDRV_RAWMIDI_LFLG_OUTPUT;
	case FMODE_READ:
		return SNDRV_RAWMIDI_LFLG_INPUT;
	default:
		return SNDRV_RAWMIDI_LFLG_OPEN;
	}
}

static inline int snd_rawmidi_ready(struct snd_rawmidi_substream *substream)
{
	struct snd_rawmidi_runtime *runtime = substream->runtime;
	return runtime->avail >= runtime->avail_min;
}

static inline int snd_rawmidi_ready_append(struct snd_rawmidi_substream *substream,
					   size_t count)
{
	struct snd_rawmidi_runtime *runtime = substream->runtime;
	return runtime->avail >= runtime->avail_min &&
	       (!substream->append || runtime->avail >= count);
}

static void snd_rawmidi_input_event_tasklet(unsigned long data)
{
	struct snd_rawmidi_substream *substream = (struct snd_rawmidi_substream *)data;
	substream->runtime->event(substream);
}

static void snd_rawmidi_output_trigger_tasklet(unsigned long data)
{
	struct snd_rawmidi_substream *substream = (struct snd_rawmidi_substream *)data;
	substream->ops->trigger(substream, 1);
}

static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
{
	struct snd_rawmidi_runtime *runtime;

	if ((runtime = kzalloc(sizeof(*runtime), GFP_KERNEL)) == NULL)
		return -ENOMEM;
	spin_lock_init(&runtime->lock);
	init_waitqueue_head(&runtime->sleep);
	if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
		tasklet_init(&runtime->tasklet,
			     snd_rawmidi_input_event_tasklet,
			     (unsigned long)substream);
	else
		tasklet_init(&runtime->tasklet,
			     snd_rawmidi_output_trigger_tasklet,
			     (unsigned long)substream);
	runtime->event = NULL;
	runtime->buffer_size = PAGE_SIZE;
	runtime->avail_min = 1;
	if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
		runtime->avail = 0;
	else
		runtime->avail = runtime->buffer_size;
	if ((runtime->buffer = kmalloc(runtime->buffer_size, GFP_KERNEL)) == NULL) {
		kfree(runtime);
		return -ENOMEM;
	}
	runtime->appl_ptr = runtime->hw_ptr = 0;
	substream->runtime = runtime;
	return 0;
}

static int snd_rawmidi_runtime_free(struct snd_rawmidi_substream *substream)
{
	struct snd_rawmidi_runtime *runtime = substream->runtime;

	kfree(runtime->buffer);
	kfree(runtime);
	substream->runtime = NULL;
	return 0;
}

static inline void snd_rawmidi_output_trigger(struct snd_rawmidi_substream *substream,int up)
{
	if (up) {
		tasklet_hi_schedule(&substream->runtime->tasklet);
	} else {
		tasklet_kill(&substream->runtime->tasklet);
		substream->ops->trigger(substream, 0);
	}
}

static void snd_rawmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
	substream->ops->trigger(substream, up);
	if (!up && substream->runtime->event)
		tasklet_kill(&substream->runtime->tasklet);
}

int snd_rawmidi_drop_output(struct snd_rawmidi_substream *substream)
{
	unsigned long flags;
	struct snd_rawmidi_runtime *runtime = substream->runtime;

	snd_rawmidi_output_trigger(substream, 0);
	runtime->drain = 0;
	spin_lock_irqsave(&runtime->lock, flags);
	runtime->appl_ptr = runtime->hw_ptr = 0;
	runtime->avail = runtime->buffer_size;
	spin_unlock_irqrestore(&runtime->lock, flags);
	return 0;
}

int snd_rawmidi_drain_output(struct snd_rawmidi_substream *substream)
{
	int err;
	long timeout;
	struct snd_rawmidi_runtime *runtime = substream->runtime;

	err = 0;
	runtime->drain = 1;
	timeout = wait_event_interruptible_timeout(runtime->sleep,
				(runtime->avail >= runtime->buffer_size),
				10*HZ);
	if (signal_pending(current))
		err = -ERESTARTSYS;
	if (runtime->avail < runtime->buffer_size && !timeout) {
		snd_printk(KERN_WARNING "rawmidi drain error (avail = %li, buffer_size = %li)\n", (long)runtime->avail, (long)runtime->buffer_size);
		err = -EIO;
	}
	runtime->drain = 0;
	if (err != -ERESTARTSYS) {
		/* we need wait a while to make sure that Tx FIFOs are empty */
		if (substream->ops->drain)
			substream->ops->drain(substream);
		else
			msleep(50);
		snd_rawmidi_drop_output(substream);
	}
	return err;
}

int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream)
{
	unsigned long flags;
	struct snd_rawmidi_runtime *runtime = substream->runtime;

	snd_rawmidi_input_trigger(substream, 0);
	runtime->drain = 0;
	spin_lock_irqsave(&runtime->lock, flags);
	runtime->appl_ptr = runtime->hw_ptr = 0;
	runtime->avail = 0;
	spin_unlock_irqrestore(&runtime->lock, flags);
	return 0;
}

int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
			    int mode, struct snd_rawmidi_file * rfile)
{
	struct snd_rawmidi *rmidi;
	struct list_head *list1, *list2;
	struct snd_rawmidi_substream *sinput = NULL, *soutput = NULL;
	struct snd_rawmidi_runtime *input = NULL, *output = NULL;
	int err;

	if (rfile)
		rfile->input = rfile->output = NULL;
	mutex_lock(&register_mutex);
	rmidi = snd_rawmidi_search(card, device);
	mutex_unlock(&register_mutex);
	if (rmidi == NULL) {
		err = -ENODEV;
		goto __error1;
	}
	if (!try_module_get(rmidi->card->module)) {
		err = -EFAULT;
		goto __error1;
	}
	if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
		mutex_lock(&rmidi->open_mutex);
	if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
		if (!(rmidi->info_flags & SNDRV_RAWMIDI_INFO_INPUT)) {
			err = -ENXIO;
			goto __error;
		}
		if (subdevice >= 0 && (unsigned int)subdevice >= rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_count) {
			err = -ENODEV;
			goto __error;
		}
		if (rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_opened >=
		    rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_count) {
			err = -EAGAIN;
			goto __error;
		}
	}
	if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
		if (!(rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT)) {
			err = -ENXIO;
			goto __error;
		}
		if (subdevice >= 0 && (unsigned int)subdevice >= rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_count) {
			err = -ENODEV;
			goto __error;
		}
		if (rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_opened >=
		    rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_count) {
			err = -EAGAIN;
			goto __error;
		}
	}
	list1 = rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams.next;
	while (1) {
		if (list1 == &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams) {
			sinput = NULL;
			if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
				err = -EAGAIN;
				goto __error;
			}
			break;
		}
		sinput = list_entry(list1, struct snd_rawmidi_substream, list);
		if ((mode & SNDRV_RAWMIDI_LFLG_INPUT) && sinput->opened)
			goto __nexti;
		if (subdevice < 0 || (subdevice >= 0 && subdevice == sinput->number))
			break;
	      __nexti:
		list1 = list1->next;
	}
	list2 = rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams.next;
	while (1) {
		if (list2 == &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams) {
			soutput = NULL;
			if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
				err = -EAGAIN;
				goto __error;
			}
			break;
		}
		soutput = list_entry(list2, struct snd_rawmidi_substream, list);
		if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
			if (mode & SNDRV_RAWMIDI_LFLG_APPEND) {
				if (soutput->opened && !soutput->append)
					goto __nexto;
			} else {
				if (soutput->opened)
					goto __nexto;
			}
		}
		if (subdevice < 0 || (subdevice >= 0 && subdevice == soutput->number))
			break;
	      __nexto:
		list2 = list2->next;
	}
	if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
		if ((err = snd_rawmidi_runtime_create(sinput)) < 0)
			goto __error;
		input = sinput->runtime;
		if ((err = sinput->ops->open(sinput)) < 0)
			goto __error;
		sinput->opened = 1;
		rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_opened++;
	} else {
		sinput = NULL;
	}
	if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
		if (soutput->opened)
			goto __skip_output;
		if ((err = snd_rawmidi_runtime_create(soutput)) < 0) {
			if (mode & SNDRV_RAWMIDI_LFLG_INPUT)
				sinput->ops->close(sinput);
			goto __error;
		}
		output = soutput->runtime;
		if ((err = soutput->ops->open(soutput)) < 0) {
			if (mode & SNDRV_RAWMIDI_LFLG_INPUT)
				sinput->ops->close(sinput);
			goto __error;
		}
	      __skip_output:
		soutput->opened = 1;
		if (mode & SNDRV_RAWMIDI_LFLG_APPEND)
			soutput->append = 1;
	      	if (soutput->use_count++ == 0)
			soutput->active_sensing = 1;
		rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_opened++;
	} else {
		soutput = NULL;
	}
	if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
		mutex_unlock(&rmidi->open_mutex);
	if (rfile) {
		rfile->rmidi = rmidi;
		rfile->input = sinput;
		rfile->output = soutput;
	}
	return 0;

      __error:
	if (input != NULL)
		snd_rawmidi_runtime_free(sinput);
	if (output != NULL)
		snd_rawmidi_runtime_free(soutput);
	module_put(rmidi->card->module);
	if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
		mutex_unlock(&rmidi->open_mutex);
      __error1:
	return err;
}

static int snd_rawmidi_open(struct inode *inode, struct file *file)
{
	int maj = imajor(inode);
	struct snd_card *card;
	int subdevice;
	unsigned short fflags;
	int err;
	struct snd_rawmidi *rmidi;
	struct snd_rawmidi_file *rawmidi_file;
	wait_queue_t wait;
	struct snd_ctl_file *kctl;

	if (maj == snd_major) {
		rmidi = snd_lookup_minor_data(iminor(inode),
					      SNDRV_DEVICE_TYPE_RAWMIDI);
#ifdef CONFIG_SND_OSSEMUL
	} else if (maj == SOUND_MAJOR) {
		rmidi = snd_lookup_oss_minor_data(iminor(inode),
						  SNDRV_OSS_DEVICE_TYPE_MIDI);
#endif
	} else
		return -ENXIO;

	if (rmidi == NULL)
		return -ENODEV;
	if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK)) 
		return -EINVAL;		/* invalid combination */
	card = rmidi->card;
	err = snd_card_file_add(card, file);
	if (err < 0)
		return -ENODEV;
	fflags = snd_rawmidi_file_flags(file);
	if ((file->f_flags & O_APPEND) || maj == SOUND_MAJOR) /* OSS emul? */
		fflags |= SNDRV_RAWMIDI_LFLG_APPEND;
	fflags |= SNDRV_RAWMIDI_LFLG_NOOPENLOCK;
	rawmidi_file = kmalloc(sizeof(*rawmidi_file), GFP_KERNEL);
	if (rawmidi_file == NULL) {
		snd_card_file_remove(card, file);
		return -ENOMEM;
	}
	init_waitqueue_entry(&wait, current);
	add_wait_queue(&rmidi->open_wait, &wait);
	mutex_lock(&rmidi->open_mutex);
	while (1) {