1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ff-hwdep.c - a part of driver for RME Fireface series
4 *
5 * Copyright (c) 2015-2017 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 "ff.h"
17
hwdep_read(struct snd_hwdep * hwdep,char __user * buf,long count,loff_t * offset)18 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
19 loff_t *offset)
20 {
21 struct snd_ff *ff = hwdep->private_data;
22 DEFINE_WAIT(wait);
23 union snd_firewire_event event;
24
25 spin_lock_irq(&ff->lock);
26
27 while (!ff->dev_lock_changed) {
28 prepare_to_wait(&ff->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
29 spin_unlock_irq(&ff->lock);
30 schedule();
31 finish_wait(&ff->hwdep_wait, &wait);
32 if (signal_pending(current))
33 return -ERESTARTSYS;
34 spin_lock_irq(&ff->lock);
35 }
36
37 memset(&event, 0, sizeof(event));
38 if (ff->dev_lock_changed) {
39 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
40 event.lock_status.status = (ff->dev_lock_count > 0);
41 ff->dev_lock_changed = false;
42
43 count = min_t(long, count, sizeof(event.lock_status));
44 }
45
46 spin_unlock_irq(&ff->lock);
47
48 if (copy_to_user(buf, &event, count))
49 return -EFAULT;
50
51 return count;
52 }
53
hwdep_poll(struct snd_hwdep * hwdep,struct file * file,poll_table * wait)54 static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
55 poll_table *wait)
56 {
57 struct snd_ff *ff = hwdep->private_data;
58 __poll_t events;
59
60 poll_wait(file, &ff->hwdep_wait, wait);
61
62 spin_lock_irq(&ff->lock);
63 if (ff->dev_lock_changed)
64 events = EPOLLIN | EPOLLRDNORM;
65 else
66 events = 0;
67 spin_unlock_irq(&ff->lock);
68
69 return events;
70 }
71
hwdep_get_info(struct snd_ff * ff,void __user * arg)72 static int hwdep_get_info(struct snd_ff *ff, void __user *arg)
73 {
74 struct fw_device *dev = fw_parent_device(ff->unit);
75 struct snd_firewire_get_info info;
76
77 memset(&info, 0, sizeof(info));
78 info.type = SNDRV_FIREWIRE_TYPE_FIREFACE;
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
hwdep_lock(struct snd_ff * ff)91 static int hwdep_lock(struct snd_ff *ff)
92 {
93 int err;
94
95 spin_lock_irq(&ff->lock);
96
97 if (ff->dev_lock_count == 0) {
98 ff->dev_lock_count = -1;
99 err = 0;
100 } else {
101 err = -EBUSY;
102 }
103
104 spin_unlock_irq(&ff->lock);
105
106 return err;
107 }
108
hwdep_unlock(struct snd_ff * ff)109 static int hwdep_unlock(struct snd_ff *ff)
110 {
111 int err;
112
113 spin_lock_irq(&ff->lock);
114
115 if (ff->dev_lock_count == -1) {
116 ff->dev_lock_count = 0;
117 err = 0;
118 } else {
119 err = -EBADFD;
120 }
121
122 spin_unlock_irq(&ff->lock);
123
124 return err;
125 }
126
hwdep_release(struct snd_hwdep * hwdep,struct file * file)127 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
128 {
129 struct snd_ff *ff = hwdep->private_data;
130
131 spin_lock_irq(&ff->lock);
132 if (ff->dev_lock_count == -1)
133 ff->dev_lock_count = 0;
134 spin_unlock_irq(&ff->lock);
135
136 return 0;
137 }
138
hwdep_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)139 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
140 unsigned int cmd, unsigned long arg)
141 {
142 struct snd_ff *ff = hwdep->private_data;
143
144 switch (cmd) {
145 case SNDRV_FIREWIRE_IOCTL_GET_INFO:
146 return hwdep_get_info(ff, (void __user *)arg);
147 case SNDRV_FIREWIRE_IOCTL_LOCK:
148 return hwdep_lock(ff);
149 case SNDRV_FIREWIRE_IOCTL_UNLOCK:
150 return hwdep_unlock(ff);
151 default:
152 return -ENOIOCTLCMD;
153 }
154 }
155
156 #ifdef CONFIG_COMPAT
hwdep_compat_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)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
snd_ff_create_hwdep_devices(struct snd_ff * ff)167 int snd_ff_create_hwdep_devices(struct snd_ff *ff)
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(ff->card, ff->card->driver, 0, &hwdep);
180 if (err < 0)
181 return err;
182
183 strcpy(hwdep->name, ff->card->driver);
184 hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREFACE;
185 hwdep->ops = hwdep_ops;
186 hwdep->private_data = ff;
187 hwdep->exclusive = true;
188
189 return 0;
190 }
191
