timer.c

linux 内核源代码

static int snd_timer_user_tselect(struct file *file,
				  struct snd_timer_select __user *_tselect)
{
	struct snd_timer_user *tu;
	struct snd_timer_select tselect;
	char str[32];
	int err = 0;

	tu = file->private_data;
	mutex_lock(&tu->tread_sem);
	if (tu->timeri) {
		snd_timer_close(tu->timeri);
		tu->timeri = NULL;
	}
	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
		err = -EFAULT;
		goto __err;
	}
	sprintf(str, "application %i", current->pid);
	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
	if (err < 0)
		goto __err;

	kfree(tu->queue);
	tu->queue = NULL;
	kfree(tu->tqueue);
	tu->tqueue = NULL;
	if (tu->tread) {
		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
				     GFP_KERNEL);
		if (tu->tqueue == NULL)
			err = -ENOMEM;
	} else {
		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
				    GFP_KERNEL);
		if (tu->queue == NULL)
			err = -ENOMEM;
	}

      	if (err < 0) {
		snd_timer_close(tu->timeri);
      		tu->timeri = NULL;
      	} else {
		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
		tu->timeri->callback = tu->tread
			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
		tu->timeri->ccallback = snd_timer_user_ccallback;
		tu->timeri->callback_data = (void *)tu;
	}

      __err:
      	mutex_unlock(&tu->tread_sem);
	return err;
}

static int snd_timer_user_info(struct file *file,
			       struct snd_timer_info __user *_info)
{
	struct snd_timer_user *tu;
	struct snd_timer_info *info;
	struct snd_timer *t;
	int err = 0;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	t = tu->timeri->timer;
	if (!t)
		return -EBADFD;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (! info)
		return -ENOMEM;
	info->card = t->card ? t->card->number : -1;
	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
		info->flags |= SNDRV_TIMER_FLG_SLAVE;
	strlcpy(info->id, t->id, sizeof(info->id));
	strlcpy(info->name, t->name, sizeof(info->name));
	info->resolution = t->hw.resolution;
	if (copy_to_user(_info, info, sizeof(*_info)))
		err = -EFAULT;
	kfree(info);
	return err;
}

static int snd_timer_user_params(struct file *file,
				 struct snd_timer_params __user *_params)
{
	struct snd_timer_user *tu;
	struct snd_timer_params params;
	struct snd_timer *t;
	struct snd_timer_read *tr;
	struct snd_timer_tread *ttr;
	int err;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	t = tu->timeri->timer;
	if (!t)
		return -EBADFD;
	if (copy_from_user(&params, _params, sizeof(params)))
		return -EFAULT;
	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
		err = -EINVAL;
		goto _end;
	}
	if (params.queue_size > 0 &&
	    (params.queue_size < 32 || params.queue_size > 1024)) {
		err = -EINVAL;
		goto _end;
	}
	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
			      (1<<SNDRV_TIMER_EVENT_TICK)|
			      (1<<SNDRV_TIMER_EVENT_START)|
			      (1<<SNDRV_TIMER_EVENT_STOP)|
			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
			      (1<<SNDRV_TIMER_EVENT_RESUME)|
			      (1<<SNDRV_TIMER_EVENT_MSTART)|
			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
		err = -EINVAL;
		goto _end;
	}
	snd_timer_stop(tu->timeri);
	spin_lock_irq(&t->lock);
	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
			       SNDRV_TIMER_IFLG_EXCLUSIVE|
			       SNDRV_TIMER_IFLG_EARLY_EVENT);
	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
	spin_unlock_irq(&t->lock);
	if (params.queue_size > 0 &&
	    (unsigned int)tu->queue_size != params.queue_size) {
		if (tu->tread) {
			ttr = kmalloc(params.queue_size * sizeof(*ttr),
				      GFP_KERNEL);
			if (ttr) {
				kfree(tu->tqueue);
				tu->queue_size = params.queue_size;
				tu->tqueue = ttr;
			}
		} else {
			tr = kmalloc(params.queue_size * sizeof(*tr),
				     GFP_KERNEL);
			if (tr) {
				kfree(tu->queue);
				tu->queue_size = params.queue_size;
				tu->queue = tr;
			}
		}
	}
	tu->qhead = tu->qtail = tu->qused = 0;
	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
		if (tu->tread) {
			struct snd_timer_tread tread;
			tread.event = SNDRV_TIMER_EVENT_EARLY;
			tread.tstamp.tv_sec = 0;
			tread.tstamp.tv_nsec = 0;
			tread.val = 0;
			snd_timer_user_append_to_tqueue(tu, &tread);
		} else {
			struct snd_timer_read *r = &tu->queue[0];
			r->resolution = 0;
			r->ticks = 0;
			tu->qused++;
			tu->qtail++;
		}
	}
	tu->filter = params.filter;
	tu->ticks = params.ticks;
	err = 0;
 _end:
	if (copy_to_user(_params, &params, sizeof(params)))
		return -EFAULT;
	return err;
}

static int snd_timer_user_status(struct file *file,
				 struct snd_timer_status __user *_status)
{
	struct snd_timer_user *tu;
	struct snd_timer_status status;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	memset(&status, 0, sizeof(status));
	status.tstamp = tu->tstamp;
	status.resolution = snd_timer_resolution(tu->timeri);
	status.lost = tu->timeri->lost;
	status.overrun = tu->overrun;
	spin_lock_irq(&tu->qlock);
	status.queue = tu->qused;
	spin_unlock_irq(&tu->qlock);
	if (copy_to_user(_status, &status, sizeof(status)))
		return -EFAULT;
	return 0;
}

static int snd_timer_user_start(struct file *file)
{
	int err;
	struct snd_timer_user *tu;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	snd_timer_stop(tu->timeri);
	tu->timeri->lost = 0;
	tu->last_resolution = 0;
	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
}

static int snd_timer_user_stop(struct file *file)
{
	int err;
	struct snd_timer_user *tu;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
}

static int snd_timer_user_continue(struct file *file)
{
	int err;
	struct snd_timer_user *tu;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	tu->timeri->lost = 0;
	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
}

static int snd_timer_user_pause(struct file *file)
{
	int err;
	struct snd_timer_user *tu;

	tu = file->private_data;
	if (!tu->timeri)
		return -EBADFD;
	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
}

enum {
	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
};

static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
				 unsigned long arg)
{
	struct snd_timer_user *tu;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;

	tu = file->private_data;
	switch (cmd) {
	case SNDRV_TIMER_IOCTL_PVERSION:
		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
		return snd_timer_user_next_device(argp);
	case SNDRV_TIMER_IOCTL_TREAD:
	{
		int xarg;

		mutex_lock(&tu->tread_sem);
		if (tu->timeri)	{	/* too late */
			mutex_unlock(&tu->tread_sem);
			return -EBUSY;
		}
		if (get_user(xarg, p)) {
			mutex_unlock(&tu->tread_sem);
			return -EFAULT;
		}
		tu->tread = xarg ? 1 : 0;
		mutex_unlock(&tu->tread_sem);
		return 0;
	}
	case SNDRV_TIMER_IOCTL_GINFO:
		return snd_timer_user_ginfo(file, argp);
	case SNDRV_TIMER_IOCTL_GPARAMS:
		return snd_timer_user_gparams(file, argp);
	case SNDRV_TIMER_IOCTL_GSTATUS:
		return snd_timer_user_gstatus(file, argp);
	case SNDRV_TIMER_IOCTL_SELECT:
		return snd_timer_user_tselect(file, argp);
	case SNDRV_TIMER_IOCTL_INFO:
		return snd_timer_user_info(file, argp);
	case SNDRV_TIMER_IOCTL_PARAMS:
		return snd_timer_user_params(file, argp);
	case SNDRV_TIMER_IOCTL_STATUS:
		return snd_timer_user_status(file, argp);
	case SNDRV_TIMER_IOCTL_START:
	case SNDRV_TIMER_IOCTL_START_OLD:
		return snd_timer_user_start(file);
	case SNDRV_TIMER_IOCTL_STOP:
	case SNDRV_TIMER_IOCTL_STOP_OLD:
		return snd_timer_user_stop(file);
	case SNDRV_TIMER_IOCTL_CONTINUE:
	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
		return snd_timer_user_continue(file);
	case SNDRV_TIMER_IOCTL_PAUSE:
	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
		return snd_timer_user_pause(file);
	}
	return -ENOTTY;
}

static int snd_timer_user_fasync(int fd, struct file * file, int on)
{
	struct snd_timer_user *tu;
	int err;

	tu = file->private_data;
	err = fasync_helper(fd, file, on, &tu->fasync);
        if (err < 0)
		return err;
	return 0;
}

static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
				   size_t count, loff_t *offset)
{
	struct snd_timer_user *tu;
	long result = 0, unit;
	int err = 0;

	tu = file->private_data;
	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
	spin_lock_irq(&tu->qlock);
	while ((long)count - result >= unit) {
		while (!tu->qused) {
			wait_queue_t wait;

			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
				err = -EAGAIN;
				break;
			}

			set_current_state(TASK_INTERRUPTIBLE);
			init_waitqueue_entry(&wait, current);
			add_wait_queue(&tu->qchange_sleep, &wait);

			spin_unlock_irq(&tu->qlock);
			schedule();
			spin_lock_irq(&tu->qlock);

			remove_wait_queue(&tu->qchange_sleep, &wait);

			if (signal_pending(current)) {
				err = -ERESTARTSYS;
				break;
			}
		}

		spin_unlock_irq(&tu->qlock);
		if (err < 0)
			goto _error;

		if (tu->tread) {
			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
					 sizeof(struct snd_timer_tread))) {
				err = -EFAULT;
				goto _error;
			}
		} else {
			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
					 sizeof(struct snd_timer_read))) {
				err = -EFAULT;
				goto _error;
			}
		}

		tu->qhead %= tu->queue_size;

		result += unit;
		buffer += unit;

		spin_lock_irq(&tu->qlock);
		tu->qused--;
	}
	spin_unlock_irq(&tu->qlock);
 _error:
	return result > 0 ? result : err;
}

static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
{
        unsigned int mask;
        struct snd_timer_user *tu;

        tu = file->private_data;

        poll_wait(file, &tu->qchange_sleep, wait);

	mask = 0;
	if (tu->qused)
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

#ifdef CONFIG_COMPAT
#include "timer_compat.c"
#else
#define snd_timer_user_ioctl_compat	NULL
#endif

static const struct file_operations snd_timer_f_ops =
{
	.owner =	THIS_MODULE,
	.read =		snd_timer_user_read,
	.open =		snd_timer_user_open,
	.release =	snd_timer_user_release,
	.poll =		snd_timer_user_poll,
	.unlocked_ioctl =	snd_timer_user_ioctl,
	.compat_ioctl =	snd_timer_user_ioctl_compat,
	.fasync = 	snd_timer_user_fasync,
};

/*
 *  ENTRY functions
 */

static int __init alsa_timer_init(void)
{
	int err;

#ifdef SNDRV_OSS_INFO_DEV_TIMERS
	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
			      "system timer");
#endif

	if ((err = snd_timer_register_system()) < 0)
		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
			   err);
	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
				       &snd_timer_f_ops, NULL, "timer")) < 0)
		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
			   err);
	snd_timer_proc_init();
	return 0;
}

static void __exit alsa_timer_exit(void)
{
	struct list_head *p, *n;

	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
	/* unregister the system timer */
	list_for_each_safe(p, n, &snd_timer_list) {
		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
		snd_timer_free(timer);
	}
	snd_timer_proc_done();
#ifdef SNDRV_OSS_INFO_DEV_TIMERS
	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
#endif
}

module_init(alsa_timer_init)
module_exit(alsa_timer_exit)

EXPORT_SYMBOL(snd_timer_open);
EXPORT_SYMBOL(snd_timer_close);
EXPORT_SYMBOL(snd_timer_resolution);
EXPORT_SYMBOL(snd_timer_start);
EXPORT_SYMBOL(snd_timer_stop);
EXPORT_SYMBOL(snd_timer_continue);
EXPORT_SYMBOL(snd_timer_pause);
EXPORT_SYMBOL(snd_timer_new);
EXPORT_SYMBOL(snd_timer_notify);
EXPORT_SYMBOL(snd_timer_global_new);
EXPORT_SYMBOL(snd_timer_global_free);
EXPORT_SYMBOL(snd_timer_global_register);
EXPORT_SYMBOL(snd_timer_interrupt);