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
18 static long
19 hwdep_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
52 static __poll_t
53 hwdep_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
70 static int
71 hwdep_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
90 static int
91 hwdep_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
109 static int
110 hwdep_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
128 static int
129 hwdep_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
141 static int
142 hwdep_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
160 static int
161 hwdep_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
171 int 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;
191 end:
192 return err;
193 }
194
195
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