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
hwdep_read(struct snd_hwdep * hwdep,char __user * buf,long count,loff_t * offset)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 if (bebob->dev_lock_changed) {
41 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
42 event.lock_status.status = (bebob->dev_lock_count > 0);
43 bebob->dev_lock_changed = false;
44 }
45
46 spin_unlock_irq(&bebob->lock);
47
48 if (copy_to_user(buf, &event, count))
49 return -EFAULT;
50
51 return count;
52 }
53
54 static __poll_t
hwdep_poll(struct snd_hwdep * hwdep,struct file * file,poll_table * wait)55 hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
56 {
57 struct snd_bebob *bebob = hwdep->private_data;
58 __poll_t events;
59
60 poll_wait(file, &bebob->hwdep_wait, wait);
61
62 spin_lock_irq(&bebob->lock);
63 if (bebob->dev_lock_changed)
64 events = EPOLLIN | EPOLLRDNORM;
65 else
66 events = 0;
67 spin_unlock_irq(&bebob->lock);
68
69 return events;
70 }
71
72 static int
hwdep_get_info(struct snd_bebob * bebob,void __user * arg)73 hwdep_get_info(struct snd_bebob *bebob, void __user *arg)
74 {
75 struct fw_device *dev = fw_parent_device(bebob->unit);
76 struct snd_firewire_get_info info;
77
78 memset(&info, 0, sizeof(info));
79 info.type = SNDRV_FIREWIRE_TYPE_BEBOB;
80 info.card = dev->card->index;
81 *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
82 *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
83 strlcpy(info.device_name, dev_name(&dev->device),
84 sizeof(info.device_name));
85
86 if (copy_to_user(arg, &info, sizeof(info)))
87 return -EFAULT;
88
89 return 0;
90 }
91
92 static int
hwdep_lock(struct snd_bebob * bebob)93 hwdep_lock(struct snd_bebob *bebob)
94 {
95 int err;
96
97 spin_lock_irq(&bebob->lock);
98
99 if (bebob->dev_lock_count == 0) {
100 bebob->dev_lock_count = -1;
101 err = 0;
102 } else {
103 err = -EBUSY;
104 }
105
106 spin_unlock_irq(&bebob->lock);
107
108 return err;
109 }
110
111 static int
hwdep_unlock(struct snd_bebob * bebob)112 hwdep_unlock(struct snd_bebob *bebob)
113 {
114 int err;
115
116 spin_lock_irq(&bebob->lock);
117
118 if (bebob->dev_lock_count == -1) {
119 bebob->dev_lock_count = 0;
120 err = 0;
121 } else {
122 err = -EBADFD;
123 }
124
125 spin_unlock_irq(&bebob->lock);
126
127 return err;
128 }
129
130 static int
hwdep_release(struct snd_hwdep * hwdep,struct file * file)131 hwdep_release(struct snd_hwdep *hwdep, struct file *file)
132 {
133 struct snd_bebob *bebob = hwdep->private_data;
134
135 spin_lock_irq(&bebob->lock);
136 if (bebob->dev_lock_count == -1)
137 bebob->dev_lock_count = 0;
138 spin_unlock_irq(&bebob->lock);
139
140 return 0;
141 }
142
143 static int
hwdep_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)144 hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
145 unsigned int cmd, unsigned long arg)
146 {
147 struct snd_bebob *bebob = hwdep->private_data;
148
149 switch (cmd) {
150 case SNDRV_FIREWIRE_IOCTL_GET_INFO:
151 return hwdep_get_info(bebob, (void __user *)arg);
152 case SNDRV_FIREWIRE_IOCTL_LOCK:
153 return hwdep_lock(bebob);
154 case SNDRV_FIREWIRE_IOCTL_UNLOCK:
155 return hwdep_unlock(bebob);
156 default:
157 return -ENOIOCTLCMD;
158 }
159 }
160
161 #ifdef CONFIG_COMPAT
162 static int
hwdep_compat_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)163 hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
164 unsigned int cmd, unsigned long arg)
165 {
166 return hwdep_ioctl(hwdep, file, cmd,
167 (unsigned long)compat_ptr(arg));
168 }
169 #else
170 #define hwdep_compat_ioctl NULL
171 #endif
172
snd_bebob_create_hwdep_device(struct snd_bebob * bebob)173 int snd_bebob_create_hwdep_device(struct snd_bebob *bebob)
174 {
175 static const struct snd_hwdep_ops ops = {
176 .read = hwdep_read,
177 .release = hwdep_release,
178 .poll = hwdep_poll,
179 .ioctl = hwdep_ioctl,
180 .ioctl_compat = hwdep_compat_ioctl,
181 };
182 struct snd_hwdep *hwdep;
183 int err;
184
185 err = snd_hwdep_new(bebob->card, "BeBoB", 0, &hwdep);
186 if (err < 0)
187 goto end;
188 strcpy(hwdep->name, "BeBoB");
189 hwdep->iface = SNDRV_HWDEP_IFACE_FW_BEBOB;
190 hwdep->ops = ops;
191 hwdep->private_data = bebob;
192 hwdep->exclusive = true;
193 end:
194 return err;
195 }
196
197