1 /*
2  * digi00x-hwdep.c - a part of driver for Digidesign Digi 002/003 family
3  *
4  * Copyright (c) 2014-2015 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  * 4.get asynchronous messaging
16  */
17 
18 #include "digi00x.h"
19 
20 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
21 		       loff_t *offset)
22 {
23 	struct snd_dg00x *dg00x = hwdep->private_data;
24 	DEFINE_WAIT(wait);
25 	union snd_firewire_event event;
26 
27 	spin_lock_irq(&dg00x->lock);
28 
29 	while (!dg00x->dev_lock_changed && dg00x->msg == 0) {
30 		prepare_to_wait(&dg00x->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
31 		spin_unlock_irq(&dg00x->lock);
32 		schedule();
33 		finish_wait(&dg00x->hwdep_wait, &wait);
34 		if (signal_pending(current))
35 			return -ERESTARTSYS;
36 		spin_lock_irq(&dg00x->lock);
37 	}
38 
39 	memset(&event, 0, sizeof(event));
40 	if (dg00x->dev_lock_changed) {
41 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
42 		event.lock_status.status = (dg00x->dev_lock_count > 0);
43 		dg00x->dev_lock_changed = false;
44 
45 		count = min_t(long, count, sizeof(event.lock_status));
46 	} else {
47 		event.digi00x_message.type =
48 					SNDRV_FIREWIRE_EVENT_DIGI00X_MESSAGE;
49 		event.digi00x_message.message = dg00x->msg;
50 		dg00x->msg = 0;
51 
52 		count = min_t(long, count, sizeof(event.digi00x_message));
53 	}
54 
55 	spin_unlock_irq(&dg00x->lock);
56 
57 	if (copy_to_user(buf, &event, count))
58 		return -EFAULT;
59 
60 	return count;
61 }
62 
63 static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
64 			       poll_table *wait)
65 {
66 	struct snd_dg00x *dg00x = hwdep->private_data;
67 	__poll_t events;
68 
69 	poll_wait(file, &dg00x->hwdep_wait, wait);
70 
71 	spin_lock_irq(&dg00x->lock);
72 	if (dg00x->dev_lock_changed || dg00x->msg)
73 		events = EPOLLIN | EPOLLRDNORM;
74 	else
75 		events = 0;
76 	spin_unlock_irq(&dg00x->lock);
77 
78 	return events;
79 }
80 
81 static int hwdep_get_info(struct snd_dg00x *dg00x, void __user *arg)
82 {
83 	struct fw_device *dev = fw_parent_device(dg00x->unit);
84 	struct snd_firewire_get_info info;
85 
86 	memset(&info, 0, sizeof(info));
87 	info.type = SNDRV_FIREWIRE_TYPE_DIGI00X;
88 	info.card = dev->card->index;
89 	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
90 	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
91 	strlcpy(info.device_name, dev_name(&dev->device),
92 		sizeof(info.device_name));
93 
94 	if (copy_to_user(arg, &info, sizeof(info)))
95 		return -EFAULT;
96 
97 	return 0;
98 }
99 
100 static int hwdep_lock(struct snd_dg00x *dg00x)
101 {
102 	int err;
103 
104 	spin_lock_irq(&dg00x->lock);
105 
106 	if (dg00x->dev_lock_count == 0) {
107 		dg00x->dev_lock_count = -1;
108 		err = 0;
109 	} else {
110 		err = -EBUSY;
111 	}
112 
113 	spin_unlock_irq(&dg00x->lock);
114 
115 	return err;
116 }
117 
118 static int hwdep_unlock(struct snd_dg00x *dg00x)
119 {
120 	int err;
121 
122 	spin_lock_irq(&dg00x->lock);
123 
124 	if (dg00x->dev_lock_count == -1) {
125 		dg00x->dev_lock_count = 0;
126 		err = 0;
127 	} else {
128 		err = -EBADFD;
129 	}
130 
131 	spin_unlock_irq(&dg00x->lock);
132 
133 	return err;
134 }
135 
136 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
137 {
138 	struct snd_dg00x *dg00x = hwdep->private_data;
139 
140 	spin_lock_irq(&dg00x->lock);
141 	if (dg00x->dev_lock_count == -1)
142 		dg00x->dev_lock_count = 0;
143 	spin_unlock_irq(&dg00x->lock);
144 
145 	return 0;
146 }
147 
148 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
149 	    unsigned int cmd, unsigned long arg)
150 {
151 	struct snd_dg00x *dg00x = hwdep->private_data;
152 
153 	switch (cmd) {
154 	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
155 		return hwdep_get_info(dg00x, (void __user *)arg);
156 	case SNDRV_FIREWIRE_IOCTL_LOCK:
157 		return hwdep_lock(dg00x);
158 	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
159 		return hwdep_unlock(dg00x);
160 	default:
161 		return -ENOIOCTLCMD;
162 	}
163 }
164 
165 #ifdef CONFIG_COMPAT
166 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
167 			      unsigned int cmd, unsigned long arg)
168 {
169 	return hwdep_ioctl(hwdep, file, cmd,
170 			   (unsigned long)compat_ptr(arg));
171 }
172 #else
173 #define hwdep_compat_ioctl NULL
174 #endif
175 
176 int snd_dg00x_create_hwdep_device(struct snd_dg00x *dg00x)
177 {
178 	static const struct snd_hwdep_ops ops = {
179 		.read		= hwdep_read,
180 		.release	= hwdep_release,
181 		.poll		= hwdep_poll,
182 		.ioctl		= hwdep_ioctl,
183 		.ioctl_compat	= hwdep_compat_ioctl,
184 	};
185 	struct snd_hwdep *hwdep;
186 	int err;
187 
188 	err = snd_hwdep_new(dg00x->card, "Digi00x", 0, &hwdep);
189 	if (err < 0)
190 		return err;
191 
192 	strcpy(hwdep->name, "Digi00x");
193 	hwdep->iface = SNDRV_HWDEP_IFACE_FW_DIGI00X;
194 	hwdep->ops = ops;
195 	hwdep->private_data = dg00x;
196 	hwdep->exclusive = true;
197 
198 	return err;
199 }
200