1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bebob_hwdep.c - a part of driver for BeBoB based devices
4 *
5 * Copyright (c) 2013-2014 Takashi Sakamoto
6 */
7
8/*
9 * This codes give three functionality.
10 *
11 * 1.get firewire node infomation
12 * 2.get notification about starting/stopping stream
13 * 3.lock/unlock stream
14 */
15
16#include "bebob.h"
17
18static long
19hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
20	   loff_t *offset)
21{
22	struct snd_bebob *bebob = hwdep->private_data;
23	DEFINE_WAIT(wait);
24	union snd_firewire_event event;
25
26	spin_lock_irq(&bebob->lock);
27
28	while (!bebob->dev_lock_changed) {
29		prepare_to_wait(&bebob->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
30		spin_unlock_irq(&bebob->lock);
31		schedule();
32		finish_wait(&bebob->hwdep_wait, &wait);
33		if (signal_pending(current))
34			return -ERESTARTSYS;
35		spin_lock_irq(&bebob->lock);
36	}
37
38	memset(&event, 0, sizeof(event));
39	count = min_t(long, count, sizeof(event.lock_status));
40	event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
41	event.lock_status.status = (bebob->dev_lock_count > 0);
42	bebob->dev_lock_changed = false;
43
44	spin_unlock_irq(&bebob->lock);
45
46	if (copy_to_user(buf, &event, count))
47		return -EFAULT;
48
49	return count;
50}
51
52static __poll_t
53hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
54{
55	struct snd_bebob *bebob = hwdep->private_data;
56	__poll_t events;
57
58	poll_wait(file, &bebob->hwdep_wait, wait);
59
60	spin_lock_irq(&bebob->lock);
61	if (bebob->dev_lock_changed)
62		events = EPOLLIN | EPOLLRDNORM;
63	else
64		events = 0;
65	spin_unlock_irq(&bebob->lock);
66
67	return events;
68}
69
70static int
71hwdep_get_info(struct snd_bebob *bebob, void __user *arg)
72{
73	struct fw_device *dev = fw_parent_device(bebob->unit);
74	struct snd_firewire_get_info info;
75
76	memset(&info, 0, sizeof(info));
77	info.type = SNDRV_FIREWIRE_TYPE_BEBOB;
78	info.card = dev->card->index;
79	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
80	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
81	strscpy(info.device_name, dev_name(&dev->device),
82		sizeof(info.device_name));
83
84	if (copy_to_user(arg, &info, sizeof(info)))
85		return -EFAULT;
86
87	return 0;
88}
89
90static int
91hwdep_lock(struct snd_bebob *bebob)
92{
93	int err;
94
95	spin_lock_irq(&bebob->lock);
96
97	if (bebob->dev_lock_count == 0) {
98		bebob->dev_lock_count = -1;
99		err = 0;
100	} else {
101		err = -EBUSY;
102	}
103
104	spin_unlock_irq(&bebob->lock);
105
106	return err;
107}
108
109static int
110hwdep_unlock(struct snd_bebob *bebob)
111{
112	int err;
113
114	spin_lock_irq(&bebob->lock);
115
116	if (bebob->dev_lock_count == -1) {
117		bebob->dev_lock_count = 0;
118		err = 0;
119	} else {
120		err = -EBADFD;
121	}
122
123	spin_unlock_irq(&bebob->lock);
124
125	return err;
126}
127
128static int
129hwdep_release(struct snd_hwdep *hwdep, struct file *file)
130{
131	struct snd_bebob *bebob = hwdep->private_data;
132
133	spin_lock_irq(&bebob->lock);
134	if (bebob->dev_lock_count == -1)
135		bebob->dev_lock_count = 0;
136	spin_unlock_irq(&bebob->lock);
137
138	return 0;
139}
140
141static int
142hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
143	    unsigned int cmd, unsigned long arg)
144{
145	struct snd_bebob *bebob = hwdep->private_data;
146
147	switch (cmd) {
148	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
149		return hwdep_get_info(bebob, (void __user *)arg);
150	case SNDRV_FIREWIRE_IOCTL_LOCK:
151		return hwdep_lock(bebob);
152	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
153		return hwdep_unlock(bebob);
154	default:
155		return -ENOIOCTLCMD;
156	}
157}
158
159#ifdef CONFIG_COMPAT
160static int
161hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
162		   unsigned int cmd, unsigned long arg)
163{
164	return hwdep_ioctl(hwdep, file, cmd,
165			   (unsigned long)compat_ptr(arg));
166}
167#else
168#define hwdep_compat_ioctl NULL
169#endif
170
171int snd_bebob_create_hwdep_device(struct snd_bebob *bebob)
172{
173	static const struct snd_hwdep_ops ops = {
174		.read		= hwdep_read,
175		.release	= hwdep_release,
176		.poll		= hwdep_poll,
177		.ioctl		= hwdep_ioctl,
178		.ioctl_compat	= hwdep_compat_ioctl,
179	};
180	struct snd_hwdep *hwdep;
181	int err;
182
183	err = snd_hwdep_new(bebob->card, "BeBoB", 0, &hwdep);
184	if (err < 0)
185		goto end;
186	strcpy(hwdep->name, "BeBoB");
187	hwdep->iface = SNDRV_HWDEP_IFACE_FW_BEBOB;
188	hwdep->ops = ops;
189	hwdep->private_data = bebob;
190	hwdep->exclusive = true;
191end:
192	return err;
193}
194
195