xref: /linux/sound/firewire/bebob/bebob_hwdep.c (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
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
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
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
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
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
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
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
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
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 
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