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	__poll_t events;
57
58	poll_wait(file, &oxfw->hwdep_wait, wait);
59
60	spin_lock_irq(&oxfw->lock);
61	if (oxfw->dev_lock_changed)
62		events = EPOLLIN | EPOLLRDNORM;
63	else
64		events = 0;
65	spin_unlock_irq(&oxfw->lock);
66
67	return events;
68}
69
70static int hwdep_get_info(struct snd_oxfw *oxfw, void __user *arg)
71{
72	struct fw_device *dev = fw_parent_device(oxfw->unit);
73	struct snd_firewire_get_info info;
74
75	memset(&info, 0, sizeof(info));
76	info.type = SNDRV_FIREWIRE_TYPE_OXFW;
77	info.card = dev->card->index;
78	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
79	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
80	strscpy(info.device_name, dev_name(&dev->device),
81		sizeof(info.device_name));
82
83	if (copy_to_user(arg, &info, sizeof(info)))
84		return -EFAULT;
85
86	return 0;
87}
88
89static int hwdep_lock(struct snd_oxfw *oxfw)
90{
91	int err;
92
93	spin_lock_irq(&oxfw->lock);
94
95	if (oxfw->dev_lock_count == 0) {
96		oxfw->dev_lock_count = -1;
97		err = 0;
98	} else {
99		err = -EBUSY;
100	}
101
102	spin_unlock_irq(&oxfw->lock);
103
104	return err;
105}
106
107static int hwdep_unlock(struct snd_oxfw *oxfw)
108{
109	int err;
110
111	spin_lock_irq(&oxfw->lock);
112
113	if (oxfw->dev_lock_count == -1) {
114		oxfw->dev_lock_count = 0;
115		err = 0;
116	} else {
117		err = -EBADFD;
118	}
119
120	spin_unlock_irq(&oxfw->lock);
121
122	return err;
123}
124
125static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
126{
127	struct snd_oxfw *oxfw = hwdep->private_data;
128
129	spin_lock_irq(&oxfw->lock);
130	if (oxfw->dev_lock_count == -1)
131		oxfw->dev_lock_count = 0;
132	spin_unlock_irq(&oxfw->lock);
133
134	return 0;
135}
136
137static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
138		       unsigned int cmd, unsigned long arg)
139{
140	struct snd_oxfw *oxfw = hwdep->private_data;
141
142	switch (cmd) {
143	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
144		return hwdep_get_info(oxfw, (void __user *)arg);
145	case SNDRV_FIREWIRE_IOCTL_LOCK:
146		return hwdep_lock(oxfw);
147	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
148		return hwdep_unlock(oxfw);
149	default:
150		return -ENOIOCTLCMD;
151	}
152}
153
154#ifdef CONFIG_COMPAT
155static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
156			      unsigned int cmd, unsigned long arg)
157{
158	return hwdep_ioctl(hwdep, file, cmd,
159			   (unsigned long)compat_ptr(arg));
160}
161#else
162#define hwdep_compat_ioctl NULL
163#endif
164
165int snd_oxfw_create_hwdep(struct snd_oxfw *oxfw)
166{
167	static const struct snd_hwdep_ops hwdep_ops = {
168		.read		= hwdep_read,
169		.release	= hwdep_release,
170		.poll		= hwdep_poll,
171		.ioctl		= hwdep_ioctl,
172		.ioctl_compat	= hwdep_compat_ioctl,
173	};
174	struct snd_hwdep *hwdep;
175	int err;
176
177	err = snd_hwdep_new(oxfw->card, oxfw->card->driver, 0, &hwdep);
178	if (err < 0)
179		goto end;
180	strcpy(hwdep->name, oxfw->card->driver);
181	hwdep->iface = SNDRV_HWDEP_IFACE_FW_OXFW;
182	hwdep->ops = hwdep_ops;
183	hwdep->private_data = oxfw;
184	hwdep->exclusive = true;
185end:
186	return err;
187}
188