xref: /openbmc/linux/sound/firewire/motu/motu-hwdep.c (revision d3964221)
1 /*
2  * motu-hwdep.c - a part of driver for MOTU FireWire series
3  *
4  * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
5  *
6  * Licensed under the terms of the GNU General Public License, version 2.
7  */
8 
9 /*
10  * This codes have five functionalities.
11  *
12  * 1.get information about firewire node
13  * 2.get notification about starting/stopping stream
14  * 3.lock/unlock streaming
15  *
16  */
17 
18 #include "motu.h"
19 
20 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
21 		       loff_t *offset)
22 {
23 	struct snd_motu *motu = hwdep->private_data;
24 	DEFINE_WAIT(wait);
25 	union snd_firewire_event event;
26 
27 	spin_lock_irq(&motu->lock);
28 
29 	while (!motu->dev_lock_changed && motu->msg == 0) {
30 		prepare_to_wait(&motu->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
31 		spin_unlock_irq(&motu->lock);
32 		schedule();
33 		finish_wait(&motu->hwdep_wait, &wait);
34 		if (signal_pending(current))
35 			return -ERESTARTSYS;
36 		spin_lock_irq(&motu->lock);
37 	}
38 
39 	memset(&event, 0, sizeof(event));
40 	if (motu->dev_lock_changed) {
41 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
42 		event.lock_status.status = (motu->dev_lock_count > 0);
43 		motu->dev_lock_changed = false;
44 
45 		count = min_t(long, count, sizeof(event.lock_status));
46 	} else {
47 		event.motu_notification.type = SNDRV_FIREWIRE_EVENT_MOTU_NOTIFICATION;
48 		event.motu_notification.message = motu->msg;
49 		motu->msg = 0;
50 
51 		count = min_t(long, count, sizeof(event.motu_notification));
52 	}
53 
54 	spin_unlock_irq(&motu->lock);
55 
56 	if (copy_to_user(buf, &event, count))
57 		return -EFAULT;
58 
59 	return count;
60 }
61 
62 static unsigned int hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
63 			       poll_table *wait)
64 {
65 	struct snd_motu *motu = hwdep->private_data;
66 	unsigned int events;
67 
68 	poll_wait(file, &motu->hwdep_wait, wait);
69 
70 	spin_lock_irq(&motu->lock);
71 	if (motu->dev_lock_changed || motu->msg)
72 		events = POLLIN | POLLRDNORM;
73 	else
74 		events = 0;
75 	spin_unlock_irq(&motu->lock);
76 
77 	return events | POLLOUT;
78 }
79 
80 static int hwdep_get_info(struct snd_motu *motu, void __user *arg)
81 {
82 	struct fw_device *dev = fw_parent_device(motu->unit);
83 	struct snd_firewire_get_info info;
84 
85 	memset(&info, 0, sizeof(info));
86 	info.type = SNDRV_FIREWIRE_TYPE_MOTU;
87 	info.card = dev->card->index;
88 	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
89 	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
90 	strlcpy(info.device_name, dev_name(&dev->device),
91 		sizeof(info.device_name));
92 
93 	if (copy_to_user(arg, &info, sizeof(info)))
94 		return -EFAULT;
95 
96 	return 0;
97 }
98 
99 static int hwdep_lock(struct snd_motu *motu)
100 {
101 	int err;
102 
103 	spin_lock_irq(&motu->lock);
104 
105 	if (motu->dev_lock_count == 0) {
106 		motu->dev_lock_count = -1;
107 		err = 0;
108 	} else {
109 		err = -EBUSY;
110 	}
111 
112 	spin_unlock_irq(&motu->lock);
113 
114 	return err;
115 }
116 
117 static int hwdep_unlock(struct snd_motu *motu)
118 {
119 	int err;
120 
121 	spin_lock_irq(&motu->lock);
122 
123 	if (motu->dev_lock_count == -1) {
124 		motu->dev_lock_count = 0;
125 		err = 0;
126 	} else {
127 		err = -EBADFD;
128 	}
129 
130 	spin_unlock_irq(&motu->lock);
131 
132 	return err;
133 }
134 
135 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
136 {
137 	struct snd_motu *motu = hwdep->private_data;
138 
139 	spin_lock_irq(&motu->lock);
140 	if (motu->dev_lock_count == -1)
141 		motu->dev_lock_count = 0;
142 	spin_unlock_irq(&motu->lock);
143 
144 	return 0;
145 }
146 
147 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
148 	    unsigned int cmd, unsigned long arg)
149 {
150 	struct snd_motu *motu = hwdep->private_data;
151 
152 	switch (cmd) {
153 	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
154 		return hwdep_get_info(motu, (void __user *)arg);
155 	case SNDRV_FIREWIRE_IOCTL_LOCK:
156 		return hwdep_lock(motu);
157 	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
158 		return hwdep_unlock(motu);
159 	default:
160 		return -ENOIOCTLCMD;
161 	}
162 }
163 
164 #ifdef CONFIG_COMPAT
165 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
166 			      unsigned int cmd, unsigned long arg)
167 {
168 	return hwdep_ioctl(hwdep, file, cmd,
169 			   (unsigned long)compat_ptr(arg));
170 }
171 #else
172 #define hwdep_compat_ioctl NULL
173 #endif
174 
175 int snd_motu_create_hwdep_device(struct snd_motu *motu)
176 {
177 	static const struct snd_hwdep_ops ops = {
178 		.read		= hwdep_read,
179 		.release	= hwdep_release,
180 		.poll		= hwdep_poll,
181 		.ioctl		= hwdep_ioctl,
182 		.ioctl_compat	= hwdep_compat_ioctl,
183 	};
184 	struct snd_hwdep *hwdep;
185 	int err;
186 
187 	err = snd_hwdep_new(motu->card, motu->card->driver, 0, &hwdep);
188 	if (err < 0)
189 		return err;
190 
191 	strcpy(hwdep->name, "MOTU");
192 	hwdep->iface = SNDRV_HWDEP_IFACE_FW_MOTU;
193 	hwdep->ops = ops;
194 	hwdep->private_data = motu;
195 	hwdep->exclusive = true;
196 
197 	return 0;
198 }
199