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
18 static 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
52 static __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
70 static 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
89 static 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
107 static 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
125 static 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
137 static 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
155 static 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
165 int 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;
185 end:
186 return err;
187 }
188
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