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