xref: /openbmc/linux/sound/firewire/oxfw/oxfw-hwdep.c (revision 9cfc5c90)
1 /*
2  * oxfw_hwdep.c - a part of driver for OXFW970/971 based devices
3  *
4  * Copyright (c) 2014 Takashi Sakamoto
5  *
6  * Licensed under the terms of the GNU General Public License, version 2.
7  */
8 
9 /*
10  * This codes give three functionality.
11  *
12  * 1.get firewire node information
13  * 2.get notification about starting/stopping stream
14  * 3.lock/unlock stream
15  */
16 
17 #include "oxfw.h"
18 
19 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
20 		       loff_t *offset)
21 {
22 	struct snd_oxfw *oxfw = hwdep->private_data;
23 	DEFINE_WAIT(wait);
24 	union snd_firewire_event event;
25 
26 	spin_lock_irq(&oxfw->lock);
27 
28 	while (!oxfw->dev_lock_changed) {
29 		prepare_to_wait(&oxfw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
30 		spin_unlock_irq(&oxfw->lock);
31 		schedule();
32 		finish_wait(&oxfw->hwdep_wait, &wait);
33 		if (signal_pending(current))
34 			return -ERESTARTSYS;
35 		spin_lock_irq(&oxfw->lock);
36 	}
37 
38 	memset(&event, 0, sizeof(event));
39 	if (oxfw->dev_lock_changed) {
40 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
41 		event.lock_status.status = (oxfw->dev_lock_count > 0);
42 		oxfw->dev_lock_changed = false;
43 
44 		count = min_t(long, count, sizeof(event.lock_status));
45 	}
46 
47 	spin_unlock_irq(&oxfw->lock);
48 
49 	if (copy_to_user(buf, &event, count))
50 		return -EFAULT;
51 
52 	return count;
53 }
54 
55 static unsigned int hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
56 			       poll_table *wait)
57 {
58 	struct snd_oxfw *oxfw = hwdep->private_data;
59 	unsigned int events;
60 
61 	poll_wait(file, &oxfw->hwdep_wait, wait);
62 
63 	spin_lock_irq(&oxfw->lock);
64 	if (oxfw->dev_lock_changed)
65 		events = POLLIN | POLLRDNORM;
66 	else
67 		events = 0;
68 	spin_unlock_irq(&oxfw->lock);
69 
70 	return events;
71 }
72 
73 static int hwdep_get_info(struct snd_oxfw *oxfw, void __user *arg)
74 {
75 	struct fw_device *dev = fw_parent_device(oxfw->unit);
76 	struct snd_firewire_get_info info;
77 
78 	memset(&info, 0, sizeof(info));
79 	info.type = SNDRV_FIREWIRE_TYPE_OXFW;
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 hwdep_lock(struct snd_oxfw *oxfw)
93 {
94 	int err;
95 
96 	spin_lock_irq(&oxfw->lock);
97 
98 	if (oxfw->dev_lock_count == 0) {
99 		oxfw->dev_lock_count = -1;
100 		err = 0;
101 	} else {
102 		err = -EBUSY;
103 	}
104 
105 	spin_unlock_irq(&oxfw->lock);
106 
107 	return err;
108 }
109 
110 static int hwdep_unlock(struct snd_oxfw *oxfw)
111 {
112 	int err;
113 
114 	spin_lock_irq(&oxfw->lock);
115 
116 	if (oxfw->dev_lock_count == -1) {
117 		oxfw->dev_lock_count = 0;
118 		err = 0;
119 	} else {
120 		err = -EBADFD;
121 	}
122 
123 	spin_unlock_irq(&oxfw->lock);
124 
125 	return err;
126 }
127 
128 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
129 {
130 	struct snd_oxfw *oxfw = hwdep->private_data;
131 
132 	spin_lock_irq(&oxfw->lock);
133 	if (oxfw->dev_lock_count == -1)
134 		oxfw->dev_lock_count = 0;
135 	spin_unlock_irq(&oxfw->lock);
136 
137 	return 0;
138 }
139 
140 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
141 		       unsigned int cmd, unsigned long arg)
142 {
143 	struct snd_oxfw *oxfw = hwdep->private_data;
144 
145 	switch (cmd) {
146 	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
147 		return hwdep_get_info(oxfw, (void __user *)arg);
148 	case SNDRV_FIREWIRE_IOCTL_LOCK:
149 		return hwdep_lock(oxfw);
150 	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
151 		return hwdep_unlock(oxfw);
152 	default:
153 		return -ENOIOCTLCMD;
154 	}
155 }
156 
157 #ifdef CONFIG_COMPAT
158 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
159 			      unsigned int cmd, unsigned long arg)
160 {
161 	return hwdep_ioctl(hwdep, file, cmd,
162 			   (unsigned long)compat_ptr(arg));
163 }
164 #else
165 #define hwdep_compat_ioctl NULL
166 #endif
167 
168 int snd_oxfw_create_hwdep(struct snd_oxfw *oxfw)
169 {
170 	static const struct snd_hwdep_ops hwdep_ops = {
171 		.read		= hwdep_read,
172 		.release	= hwdep_release,
173 		.poll		= hwdep_poll,
174 		.ioctl		= hwdep_ioctl,
175 		.ioctl_compat	= hwdep_compat_ioctl,
176 	};
177 	struct snd_hwdep *hwdep;
178 	int err;
179 
180 	err = snd_hwdep_new(oxfw->card, oxfw->card->driver, 0, &hwdep);
181 	if (err < 0)
182 		goto end;
183 	strcpy(hwdep->name, oxfw->card->driver);
184 	hwdep->iface = SNDRV_HWDEP_IFACE_FW_OXFW;
185 	hwdep->ops = hwdep_ops;
186 	hwdep->private_data = oxfw;
187 	hwdep->exclusive = true;
188 end:
189 	return err;
190 }
191