tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
18static 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 if (oxfw->dev_lock_changed) {
39 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
40 event.lock_status.status = (oxfw->dev_lock_count > 0);
41 oxfw->dev_lock_changed = false;
42
43 count = min_t(long, count, sizeof(event.lock_status));
44 }
45
46 spin_unlock_irq(&oxfw->lock);
47
48 if (copy_to_user(buf, &event, count))
49 return -EFAULT;
50
51 return count;
52}
53
54static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
55 poll_table *wait)
56{
57 struct snd_oxfw *oxfw = hwdep->private_data;
58 __poll_t events;
59
60 poll_wait(file, &oxfw->hwdep_wait, wait);
61
62 spin_lock_irq(&oxfw->lock);
63 if (oxfw->dev_lock_changed)
64 events = EPOLLIN | EPOLLRDNORM;
65 else
66 events = 0;
67 spin_unlock_irq(&oxfw->lock);
68
69 return events;
70}
71
72static int hwdep_get_info(struct snd_oxfw *oxfw, void __user *arg)
73{
74 struct fw_device *dev = fw_parent_device(oxfw->unit);
75 struct snd_firewire_get_info info;
76
77 memset(&info, 0, sizeof(info));
78 info.type = SNDRV_FIREWIRE_TYPE_OXFW;
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 strlcpy(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
91static int hwdep_lock(struct snd_oxfw *oxfw)
92{
93 int err;
94
95 spin_lock_irq(&oxfw->lock);
96
97 if (oxfw->dev_lock_count == 0) {
98 oxfw->dev_lock_count = -1;
99 err = 0;
100 } else {
101 err = -EBUSY;
102 }
103
104 spin_unlock_irq(&oxfw->lock);
105
106 return err;
107}
108
109static int hwdep_unlock(struct snd_oxfw *oxfw)
110{
111 int err;
112
113 spin_lock_irq(&oxfw->lock);
114
115 if (oxfw->dev_lock_count == -1) {
116 oxfw->dev_lock_count = 0;
117 err = 0;
118 } else {
119 err = -EBADFD;
120 }
121
122 spin_unlock_irq(&oxfw->lock);
123
124 return err;
125}
126
127static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
128{
129 struct snd_oxfw *oxfw = hwdep->private_data;
130
131 spin_lock_irq(&oxfw->lock);
132 if (oxfw->dev_lock_count == -1)
133 oxfw->dev_lock_count = 0;
134 spin_unlock_irq(&oxfw->lock);
135
136 return 0;
137}
138
139static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
140 unsigned int cmd, unsigned long arg)
141{
142 struct snd_oxfw *oxfw = hwdep->private_data;
143
144 switch (cmd) {
145 case SNDRV_FIREWIRE_IOCTL_GET_INFO:
146 return hwdep_get_info(oxfw, (void __user *)arg);
147 case SNDRV_FIREWIRE_IOCTL_LOCK:
148 return hwdep_lock(oxfw);
149 case SNDRV_FIREWIRE_IOCTL_UNLOCK:
150 return hwdep_unlock(oxfw);
151 default:
152 return -ENOIOCTLCMD;
153 }
154}
155
156#ifdef CONFIG_COMPAT
157static 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
167int snd_oxfw_create_hwdep(struct snd_oxfw *oxfw)
168{
169 static const struct snd_hwdep_ops hwdep_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(oxfw->card, oxfw->card->driver, 0, &hwdep);
180 if (err < 0)
181 goto end;
182 strcpy(hwdep->name, oxfw->card->driver);
183 hwdep->iface = SNDRV_HWDEP_IFACE_FW_OXFW;
184 hwdep->ops = hwdep_ops;
185 hwdep->private_data = oxfw;
186 hwdep->exclusive = true;
187end:
188 return err;
189}