oxfw-hwdep.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * oxfw_hwdep.c - a part of driver for OXFW970/971 based devices
  4 *
  5 * Copyright (c) 2014 Takashi Sakamoto
  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 "oxfw.h"
 17
 18static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
 19		       loff_t *offset)
 20{
 21	struct snd_oxfw *oxfw = hwdep->private_data;
 22	DEFINE_WAIT(wait);
 23	union snd_firewire_event event;
 24
 25	spin_lock_irq(&oxfw->lock);
 26
 27	while (!oxfw->dev_lock_changed) {
 28		prepare_to_wait(&oxfw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
 29		spin_unlock_irq(&oxfw->lock);
 30		schedule();
 31		finish_wait(&oxfw->hwdep_wait, &wait);
 32		if (signal_pending(current))
 33			return -ERESTARTSYS;
 34		spin_lock_irq(&oxfw->lock);
 35	}
 36
 37	memset(&event, 0, sizeof(event));
 38	event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
 39	event.lock_status.status = (oxfw->dev_lock_count > 0);
 40	oxfw->dev_lock_changed = false;
 41
 42	count = min_t(long, count, sizeof(event.lock_status));
 43
 44	spin_unlock_irq(&oxfw->lock);
 45
 46	if (copy_to_user(buf, &event, count))
 47		return -EFAULT;
 48
 49	return count;
 50}
 51
 52static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
 53			       poll_table *wait)
 54{
 55	struct snd_oxfw *oxfw = hwdep->private_data;
 56
 57	poll_wait(file, &oxfw->hwdep_wait, wait);
 58
 59	guard(spinlock_irq)(&oxfw->lock);
 60	if (oxfw->dev_lock_changed)
 61		return EPOLLIN | EPOLLRDNORM;
 62	else
 63		return 0;
 64}
 65
 66static int hwdep_get_info(struct snd_oxfw *oxfw, void __user *arg)
 67{
 68	struct fw_device *dev = fw_parent_device(oxfw->unit);
 69	struct snd_firewire_get_info info;
 70
 71	memset(&info, 0, sizeof(info));
 72	info.type = SNDRV_FIREWIRE_TYPE_OXFW;
 73	info.card = dev->card->index;
 74	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
 75	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
 76	strscpy(info.device_name, dev_name(&dev->device),
 77		sizeof(info.device_name));
 78
 79	if (copy_to_user(arg, &info, sizeof(info)))
 80		return -EFAULT;
 81
 82	return 0;
 83}
 84
 85static int hwdep_lock(struct snd_oxfw *oxfw)
 86{
 87	guard(spinlock_irq)(&oxfw->lock);
 88
 89	if (oxfw->dev_lock_count == 0) {
 90		oxfw->dev_lock_count = -1;
 91		return 0;
 92	} else {
 93		return -EBUSY;
 94	}
 95}
 96
 97static int hwdep_unlock(struct snd_oxfw *oxfw)
 98{
 99	guard(spinlock_irq)(&oxfw->lock);
100
101	if (oxfw->dev_lock_count == -1) {
102		oxfw->dev_lock_count = 0;
103		return 0;
104	} else {
105		return -EBADFD;
106	}
107}
108
109static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
110{
111	struct snd_oxfw *oxfw = hwdep->private_data;
112
113	guard(spinlock_irq)(&oxfw->lock);
114	if (oxfw->dev_lock_count == -1)
115		oxfw->dev_lock_count = 0;
116
117	return 0;
118}
119
120static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
121		       unsigned int cmd, unsigned long arg)
122{
123	struct snd_oxfw *oxfw = hwdep->private_data;
124
125	switch (cmd) {
126	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
127		return hwdep_get_info(oxfw, (void __user *)arg);
128	case SNDRV_FIREWIRE_IOCTL_LOCK:
129		return hwdep_lock(oxfw);
130	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
131		return hwdep_unlock(oxfw);
132	default:
133		return -ENOIOCTLCMD;
134	}
135}
136
137#ifdef CONFIG_COMPAT
138static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
139			      unsigned int cmd, unsigned long arg)
140{
141	return hwdep_ioctl(hwdep, file, cmd,
142			   (unsigned long)compat_ptr(arg));
143}
144#else
145#define hwdep_compat_ioctl NULL
146#endif
147
148int snd_oxfw_create_hwdep(struct snd_oxfw *oxfw)
149{
150	static const struct snd_hwdep_ops hwdep_ops = {
151		.read		= hwdep_read,
152		.release	= hwdep_release,
153		.poll		= hwdep_poll,
154		.ioctl		= hwdep_ioctl,
155		.ioctl_compat	= hwdep_compat_ioctl,
156	};
157	struct snd_hwdep *hwdep;
158	int err;
159
160	err = snd_hwdep_new(oxfw->card, oxfw->card->driver, 0, &hwdep);
161	if (err < 0)
162		goto end;
163	strscpy(hwdep->name, oxfw->card->driver);
164	hwdep->iface = SNDRV_HWDEP_IFACE_FW_OXFW;
165	hwdep->ops = hwdep_ops;
166	hwdep->private_data = oxfw;
167	hwdep->exclusive = true;
168end:
169	return err;
170}