[linux-2.6-block.git] / sound / firewire / tascam / tascam-hwdep.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * tascam-hwdep.c - a part of driver for TASCAM FireWire series
 *
 * Copyright (c) 2015 Takashi Sakamoto
 */

/*
 * This codes give three functionality.
 *
 * 1.get firewire node information
 * 2.get notification about starting/stopping stream
 * 3.lock/unlock stream
 */

#include "tascam.h"

static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,
				   long count, loff_t *offset)
{
	struct snd_firewire_event_lock_status event = {
		.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
	};

	event.status = (tscm->dev_lock_count > 0);
	tscm->dev_lock_changed = false;
	count = min_t(long, count, sizeof(event));

	spin_unlock_irq(&tscm->lock);

	if (copy_to_user(buf, &event, count))
		return -EFAULT;

	return count;
}

static long tscm_hwdep_read_queue(struct snd_tscm *tscm, char __user *buf,
				  long remained, loff_t *offset)
{
	char __user *pos = buf;
	unsigned int type = SNDRV_FIREWIRE_EVENT_TASCAM_CONTROL;
	struct snd_firewire_tascam_change *entries = tscm->queue;
	long count;

	// At least, one control event can be copied.
	if (remained < sizeof(type) + sizeof(*entries)) {
		spin_unlock_irq(&tscm->lock);
		return -EINVAL;
	}

	// Copy the type field later.
	count = sizeof(type);
	remained -= sizeof(type);
	pos += sizeof(type);

	while (true) {
		unsigned int head_pos;
		unsigned int tail_pos;
		unsigned int length;

		if (tscm->pull_pos == tscm->push_pos)
			break;
		else if (tscm->pull_pos < tscm->push_pos)
			tail_pos = tscm->push_pos;
		else
			tail_pos = SND_TSCM_QUEUE_COUNT;
		head_pos = tscm->pull_pos;

		length = (tail_pos - head_pos) * sizeof(*entries);
		if (remained < length)
			length = rounddown(remained, sizeof(*entries));
		if (length == 0)
			break;

		spin_unlock_irq(&tscm->lock);
		if (copy_to_user(pos, &entries[head_pos], length))
			return -EFAULT;

		spin_lock_irq(&tscm->lock);

		tscm->pull_pos = tail_pos % SND_TSCM_QUEUE_COUNT;

		count += length;
		remained -= length;
		pos += length;
	}

	spin_unlock_irq(&tscm->lock);

	if (copy_to_user(buf, &type, sizeof(type)))
		return -EFAULT;

	return count;
}

static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
		       loff_t *offset)
{
	struct snd_tscm *tscm = hwdep->private_data;
	DEFINE_WAIT(wait);

	spin_lock_irq(&tscm->lock);

	while (!tscm->dev_lock_changed && tscm->push_pos == tscm->pull_pos) {
		prepare_to_wait(&tscm->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
		spin_unlock_irq(&tscm->lock);
		schedule();
		finish_wait(&tscm->hwdep_wait, &wait);
		if (signal_pending(current))
			return -ERESTARTSYS;
		spin_lock_irq(&tscm->lock);
	}

	// NOTE: The acquired lock should be released in callee side.
	if (tscm->dev_lock_changed) {
		count = tscm_hwdep_read_locked(tscm, buf, count, offset);
	} else if (tscm->push_pos != tscm->pull_pos) {
		count = tscm_hwdep_read_queue(tscm, buf, count, offset);
	} else {
		spin_unlock_irq(&tscm->lock);
		count = 0;
	}

	return count;
}

static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
			       poll_table *wait)
{
	struct snd_tscm *tscm = hwdep->private_data;
	__poll_t events;

	poll_wait(file, &tscm->hwdep_wait, wait);

	spin_lock_irq(&tscm->lock);
	if (tscm->dev_lock_changed || tscm->push_pos != tscm->pull_pos)
		events = EPOLLIN | EPOLLRDNORM;
	else
		events = 0;
	spin_unlock_irq(&tscm->lock);

	return events;
}

static int hwdep_get_info(struct snd_tscm *tscm, void __user *arg)
{
	struct fw_device *dev = fw_parent_device(tscm->unit);
	struct snd_firewire_get_info info;

	memset(&info, 0, sizeof(info));
	info.type = SNDRV_FIREWIRE_TYPE_TASCAM;
	info.card = dev->card->index;
	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
	strlcpy(info.device_name, dev_name(&dev->device),
		sizeof(info.device_name));

	if (copy_to_user(arg, &info, sizeof(info)))
		return -EFAULT;

	return 0;
}

static int hwdep_lock(struct snd_tscm *tscm)
{
	int err;

	spin_lock_irq(&tscm->lock);

	if (tscm->dev_lock_count == 0) {
		tscm->dev_lock_count = -1;
		err = 0;
	} else {
		err = -EBUSY;
	}

	spin_unlock_irq(&tscm->lock);

	return err;
}

static int hwdep_unlock(struct snd_tscm *tscm)
{
	int err;

	spin_lock_irq(&tscm->lock);

	if (tscm->dev_lock_count == -1) {
		tscm->dev_lock_count = 0;
		err = 0;
	} else {
		err = -EBADFD;
	}

	spin_unlock_irq(&tscm->lock);

	return err;
}

static int tscm_hwdep_state(struct snd_tscm *tscm, void __user *arg)
{
	if (copy_to_user(arg, tscm->state, sizeof(tscm->state)))
		return -EFAULT;

	return 0;
}

static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
{
	struct snd_tscm *tscm = hwdep->private_data;

	spin_lock_irq(&tscm->lock);
	if (tscm->dev_lock_count == -1)
		tscm->dev_lock_count = 0;
	spin_unlock_irq(&tscm->lock);

	return 0;
}

static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
	    unsigned int cmd, unsigned long arg)
{
	struct snd_tscm *tscm = hwdep->private_data;

	switch (cmd) {
	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
		return hwdep_get_info(tscm, (void __user *)arg);
	case SNDRV_FIREWIRE_IOCTL_LOCK:
		return hwdep_lock(tscm);
	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
		return hwdep_unlock(tscm);
	case SNDRV_FIREWIRE_IOCTL_TASCAM_STATE:
		return tscm_hwdep_state(tscm, (void __user *)arg);
	default:
		return -ENOIOCTLCMD;
	}
}

#ifdef CONFIG_COMPAT
static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
			      unsigned int cmd, unsigned long arg)
{
	return hwdep_ioctl(hwdep, file, cmd,
			   (unsigned long)compat_ptr(arg));
}
#else
#define hwdep_compat_ioctl NULL
#endif

int snd_tscm_create_hwdep_device(struct snd_tscm *tscm)
{
	static const struct snd_hwdep_ops ops = {
		.read		= hwdep_read,
		.release	= hwdep_release,
		.poll		= hwdep_poll,
		.ioctl		= hwdep_ioctl,
		.ioctl_compat	= hwdep_compat_ioctl,
	};
	struct snd_hwdep *hwdep;
	int err;

	err = snd_hwdep_new(tscm->card, "Tascam", 0, &hwdep);
	if (err < 0)
		return err;

	strcpy(hwdep->name, "Tascam");
	hwdep->iface = SNDRV_HWDEP_IFACE_FW_TASCAM;
	hwdep->ops = ops;
	hwdep->private_data = tscm;
	hwdep->exclusive = true;

	tscm->hwdep = hwdep;

	return err;
}
Commit	Line	Data
da607e19	1	// SPDX-License-Identifier: GPL-2.0-only
e5e0c3dd TS	2	/*
	3	* tascam-hwdep.c - a part of driver for TASCAM FireWire series
	4	*
	5	* Copyright (c) 2015 Takashi Sakamoto
e5e0c3dd TS	6	*/
	7
	8	/*
	9	* This codes give three functionality.
	10	*
	11	* 1.get firewire node information
	12	* 2.get notification about starting/stopping stream
	13	* 3.lock/unlock stream
	14	*/
	15
	16	#include "tascam.h"
	17
afb8e2da TS	18	static long tscm_hwdep_read_locked(struct snd_tscm tscm, char __user buf,
	19	long count, loff_t *offset)
	20	{
	21	struct snd_firewire_event_lock_status event = {
	22	.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
	23	};
	24
	25	event.status = (tscm->dev_lock_count > 0);
	26	tscm->dev_lock_changed = false;
	27	count = min_t(long, count, sizeof(event));
	28
	29	spin_unlock_irq(&tscm->lock);
	30
	31	if (copy_to_user(buf, &event, count))
	32	return -EFAULT;
	33
	34	return count;
	35	}
	36
a8c0d132 TS	37	static long tscm_hwdep_read_queue(struct snd_tscm tscm, char __user buf,
	38	long remained, loff_t *offset)
	39	{
	40	char __user *pos = buf;
	41	unsigned int type = SNDRV_FIREWIRE_EVENT_TASCAM_CONTROL;
	42	struct snd_firewire_tascam_change *entries = tscm->queue;
	43	long count;
	44
	45	// At least, one control event can be copied.
	46	if (remained < sizeof(type) + sizeof(*entries)) {
	47	spin_unlock_irq(&tscm->lock);
	48	return -EINVAL;
	49	}
	50
	51	// Copy the type field later.
	52	count = sizeof(type);
	53	remained -= sizeof(type);
	54	pos += sizeof(type);
	55
	56	while (true) {
	57	unsigned int head_pos;
	58	unsigned int tail_pos;
	59	unsigned int length;
	60
	61	if (tscm->pull_pos == tscm->push_pos)
	62	break;
	63	else if (tscm->pull_pos < tscm->push_pos)
	64	tail_pos = tscm->push_pos;
	65	else
	66	tail_pos = SND_TSCM_QUEUE_COUNT;
	67	head_pos = tscm->pull_pos;
	68
	69	length = (tail_pos - head_pos) * sizeof(*entries);
	70	if (remained < length)
	71	length = rounddown(remained, sizeof(*entries));
	72	if (length == 0)
	73	break;
	74
	75	spin_unlock_irq(&tscm->lock);
	76	if (copy_to_user(pos, &entries[head_pos], length))
	77	return -EFAULT;
	78
	79	spin_lock_irq(&tscm->lock);
	80
	81	tscm->pull_pos = tail_pos % SND_TSCM_QUEUE_COUNT;
	82
	83	count += length;
	84	remained -= length;
	85	pos += length;
	86	}
	87
	88	spin_unlock_irq(&tscm->lock);
	89
	90	if (copy_to_user(buf, &type, sizeof(type)))
	91	return -EFAULT;
	92
	93	return count;
	94	}
	95
e5e0c3dd TS	96	static long hwdep_read(struct snd_hwdep hwdep, char __user buf, long count,
	97	loff_t *offset)
	98	{
	99	struct snd_tscm *tscm = hwdep->private_data;
	100	DEFINE_WAIT(wait);
e5e0c3dd TS	101
	102	spin_lock_irq(&tscm->lock);
	103
a8c0d132	104	while (!tscm->dev_lock_changed && tscm->push_pos == tscm->pull_pos) {
e5e0c3dd TS	105	prepare_to_wait(&tscm->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
	106	spin_unlock_irq(&tscm->lock);
	107	schedule();
	108	finish_wait(&tscm->hwdep_wait, &wait);
	109	if (signal_pending(current))
	110	return -ERESTARTSYS;
	111	spin_lock_irq(&tscm->lock);
	112	}
	113
afb8e2da TS	114	// NOTE: The acquired lock should be released in callee side.
	115	if (tscm->dev_lock_changed) {
	116	count = tscm_hwdep_read_locked(tscm, buf, count, offset);
a8c0d132 TS	117	} else if (tscm->push_pos != tscm->pull_pos) {
a8c0d132 TS	118	count = tscm_hwdep_read_queue(tscm, buf, count, offset);
afb8e2da TS	119	} else {
	120	spin_unlock_irq(&tscm->lock);
	121	count = 0;
	122	}
04b2d9c9	123
e5e0c3dd TS	124	return count;
	125	}
	126
680ef72a	127	static __poll_t hwdep_poll(struct snd_hwdep hwdep, struct file file,
e5e0c3dd TS	128	poll_table *wait)
	129	{
	130	struct snd_tscm *tscm = hwdep->private_data;
680ef72a	131	__poll_t events;
e5e0c3dd TS	132
	133	poll_wait(file, &tscm->hwdep_wait, wait);
	134
	135	spin_lock_irq(&tscm->lock);
a8c0d132	136	if (tscm->dev_lock_changed \|\| tscm->push_pos != tscm->pull_pos)
a9a08845	137	events = EPOLLIN \| EPOLLRDNORM;
e5e0c3dd TS	138	else
	139	events = 0;
	140	spin_unlock_irq(&tscm->lock);
	141
	142	return events;
	143	}
	144
	145	static int hwdep_get_info(struct snd_tscm tscm, void __user arg)
	146	{
	147	struct fw_device *dev = fw_parent_device(tscm->unit);
	148	struct snd_firewire_get_info info;
	149
	150	memset(&info, 0, sizeof(info));
	151	info.type = SNDRV_FIREWIRE_TYPE_TASCAM;
	152	info.card = dev->card->index;
	153	(__be32 )&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
	154	(__be32 )&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
	155	strlcpy(info.device_name, dev_name(&dev->device),
	156	sizeof(info.device_name));
	157
	158	if (copy_to_user(arg, &info, sizeof(info)))
	159	return -EFAULT;
	160
	161	return 0;
	162	}
	163
	164	static int hwdep_lock(struct snd_tscm *tscm)
	165	{
	166	int err;
	167
	168	spin_lock_irq(&tscm->lock);
	169
	170	if (tscm->dev_lock_count == 0) {
	171	tscm->dev_lock_count = -1;
	172	err = 0;
	173	} else {
	174	err = -EBUSY;
	175	}
	176
	177	spin_unlock_irq(&tscm->lock);
	178
	179	return err;
	180	}
	181
	182	static int hwdep_unlock(struct snd_tscm *tscm)
	183	{
	184	int err;
	185
	186	spin_lock_irq(&tscm->lock);
	187
	188	if (tscm->dev_lock_count == -1) {
	189	tscm->dev_lock_count = 0;
	190	err = 0;
	191	} else {
	192	err = -EBADFD;
	193	}
	194
	195	spin_unlock_irq(&tscm->lock);
	196
	197	return err;
	198	}
	199
90e8ac5c TS	200	static int tscm_hwdep_state(struct snd_tscm tscm, void __user arg)
	201	{
	202	if (copy_to_user(arg, tscm->state, sizeof(tscm->state)))
	203	return -EFAULT;
	204
	205	return 0;
	206	}
	207
e5e0c3dd TS	208	static int hwdep_release(struct snd_hwdep hwdep, struct file file)
	209	{
	210	struct snd_tscm *tscm = hwdep->private_data;
	211
	212	spin_lock_irq(&tscm->lock);
	213	if (tscm->dev_lock_count == -1)
	214	tscm->dev_lock_count = 0;
	215	spin_unlock_irq(&tscm->lock);
	216
	217	return 0;
	218	}
	219
	220	static int hwdep_ioctl(struct snd_hwdep hwdep, struct file file,
	221	unsigned int cmd, unsigned long arg)
	222	{
	223	struct snd_tscm *tscm = hwdep->private_data;
	224
	225	switch (cmd) {
	226	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
	227	return hwdep_get_info(tscm, (void __user *)arg);
	228	case SNDRV_FIREWIRE_IOCTL_LOCK:
	229	return hwdep_lock(tscm);
	230	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
	231	return hwdep_unlock(tscm);
90e8ac5c TS	232	case SNDRV_FIREWIRE_IOCTL_TASCAM_STATE:
90e8ac5c TS	233	return tscm_hwdep_state(tscm, (void __user *)arg);
e5e0c3dd TS	234	default:
	235	return -ENOIOCTLCMD;
	236	}
	237	}
	238
	239	#ifdef CONFIG_COMPAT
	240	static int hwdep_compat_ioctl(struct snd_hwdep hwdep, struct file file,
	241	unsigned int cmd, unsigned long arg)
	242	{
	243	return hwdep_ioctl(hwdep, file, cmd,
	244	(unsigned long)compat_ptr(arg));
	245	}
	246	#else
	247	#define hwdep_compat_ioctl NULL
	248	#endif
	249
e5e0c3dd TS	250	int snd_tscm_create_hwdep_device(struct snd_tscm *tscm)
e5e0c3dd TS	251	{
92128236 TS	252	static const struct snd_hwdep_ops ops = {
	253	.read = hwdep_read,
	254	.release = hwdep_release,
	255	.poll = hwdep_poll,
	256	.ioctl = hwdep_ioctl,
	257	.ioctl_compat = hwdep_compat_ioctl,
	258	};
e5e0c3dd TS	259	struct snd_hwdep *hwdep;
	260	int err;
	261
	262	err = snd_hwdep_new(tscm->card, "Tascam", 0, &hwdep);
	263	if (err < 0)
	264	return err;
	265
	266	strcpy(hwdep->name, "Tascam");
	267	hwdep->iface = SNDRV_HWDEP_IFACE_FW_TASCAM;
92128236	268	hwdep->ops = ops;
e5e0c3dd TS	269	hwdep->private_data = tscm;
	270	hwdep->exclusive = true;
	271
d7167422 TS	272	tscm->hwdep = hwdep;
d7167422 TS	273
e5e0c3dd TS	274	return err;
e5e0c3dd TS	275	}