xref: /linux/sound/firewire/digi00x/digi00x-hwdep.c (revision 05a54fa773284d1a7923cdfdd8f0c8dabb98bd26)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * digi00x-hwdep.c - a part of driver for Digidesign Digi 002/003 family
4  *
5  * Copyright (c) 2014-2015 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  * 4.get asynchronous messaging
15  */
16 
17 #include "digi00x.h"
18 
19 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
20 		       loff_t *offset)
21 {
22 	struct snd_dg00x *dg00x = hwdep->private_data;
23 	DEFINE_WAIT(wait);
24 	union snd_firewire_event event;
25 
26 	spin_lock_irq(&dg00x->lock);
27 
28 	while (!dg00x->dev_lock_changed && dg00x->msg == 0) {
29 		prepare_to_wait(&dg00x->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
30 		spin_unlock_irq(&dg00x->lock);
31 		schedule();
32 		finish_wait(&dg00x->hwdep_wait, &wait);
33 		if (signal_pending(current))
34 			return -ERESTARTSYS;
35 		spin_lock_irq(&dg00x->lock);
36 	}
37 
38 	memset(&event, 0, sizeof(event));
39 	if (dg00x->dev_lock_changed) {
40 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
41 		event.lock_status.status = (dg00x->dev_lock_count > 0);
42 		dg00x->dev_lock_changed = false;
43 
44 		count = min_t(long, count, sizeof(event.lock_status));
45 	} else {
46 		event.digi00x_message.type =
47 					SNDRV_FIREWIRE_EVENT_DIGI00X_MESSAGE;
48 		event.digi00x_message.message = dg00x->msg;
49 		dg00x->msg = 0;
50 
51 		count = min_t(long, count, sizeof(event.digi00x_message));
52 	}
53 
54 	spin_unlock_irq(&dg00x->lock);
55 
56 	if (copy_to_user(buf, &event, count))
57 		return -EFAULT;
58 
59 	return count;
60 }
61 
62 static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
63 			       poll_table *wait)
64 {
65 	struct snd_dg00x *dg00x = hwdep->private_data;
66 
67 	poll_wait(file, &dg00x->hwdep_wait, wait);
68 
69 	guard(spinlock_irq)(&dg00x->lock);
70 	if (dg00x->dev_lock_changed || dg00x->msg)
71 		return EPOLLIN | EPOLLRDNORM;
72 	else
73 		return 0;
74 }
75 
76 static int hwdep_get_info(struct snd_dg00x *dg00x, void __user *arg)
77 {
78 	struct fw_device *dev = fw_parent_device(dg00x->unit);
79 	struct snd_firewire_get_info info;
80 
81 	memset(&info, 0, sizeof(info));
82 	info.type = SNDRV_FIREWIRE_TYPE_DIGI00X;
83 	info.card = dev->card->index;
84 	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
85 	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
86 	strscpy(info.device_name, dev_name(&dev->device),
87 		sizeof(info.device_name));
88 
89 	if (copy_to_user(arg, &info, sizeof(info)))
90 		return -EFAULT;
91 
92 	return 0;
93 }
94 
95 static int hwdep_lock(struct snd_dg00x *dg00x)
96 {
97 	guard(spinlock_irq)(&dg00x->lock);
98 
99 	if (dg00x->dev_lock_count == 0) {
100 		dg00x->dev_lock_count = -1;
101 		return 0;
102 	} else {
103 		return -EBUSY;
104 	}
105 }
106 
107 static int hwdep_unlock(struct snd_dg00x *dg00x)
108 {
109 	guard(spinlock_irq)(&dg00x->lock);
110 
111 	if (dg00x->dev_lock_count == -1) {
112 		dg00x->dev_lock_count = 0;
113 		return 0;
114 	} else {
115 		return -EBADFD;
116 	}
117 }
118 
119 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
120 {
121 	struct snd_dg00x *dg00x = hwdep->private_data;
122 
123 	guard(spinlock_irq)(&dg00x->lock);
124 	if (dg00x->dev_lock_count == -1)
125 		dg00x->dev_lock_count = 0;
126 
127 	return 0;
128 }
129 
130 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
131 	    unsigned int cmd, unsigned long arg)
132 {
133 	struct snd_dg00x *dg00x = hwdep->private_data;
134 
135 	switch (cmd) {
136 	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
137 		return hwdep_get_info(dg00x, (void __user *)arg);
138 	case SNDRV_FIREWIRE_IOCTL_LOCK:
139 		return hwdep_lock(dg00x);
140 	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
141 		return hwdep_unlock(dg00x);
142 	default:
143 		return -ENOIOCTLCMD;
144 	}
145 }
146 
147 #ifdef CONFIG_COMPAT
148 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
149 			      unsigned int cmd, unsigned long arg)
150 {
151 	return hwdep_ioctl(hwdep, file, cmd,
152 			   (unsigned long)compat_ptr(arg));
153 }
154 #else
155 #define hwdep_compat_ioctl NULL
156 #endif
157 
158 int snd_dg00x_create_hwdep_device(struct snd_dg00x *dg00x)
159 {
160 	static const struct snd_hwdep_ops ops = {
161 		.read		= hwdep_read,
162 		.release	= hwdep_release,
163 		.poll		= hwdep_poll,
164 		.ioctl		= hwdep_ioctl,
165 		.ioctl_compat	= hwdep_compat_ioctl,
166 	};
167 	struct snd_hwdep *hwdep;
168 	int err;
169 
170 	err = snd_hwdep_new(dg00x->card, "Digi00x", 0, &hwdep);
171 	if (err < 0)
172 		return err;
173 
174 	strscpy(hwdep->name, "Digi00x");
175 	hwdep->iface = SNDRV_HWDEP_IFACE_FW_DIGI00X;
176 	hwdep->ops = ops;
177 	hwdep->private_data = dg00x;
178 	hwdep->exclusive = true;
179 
180 	return err;
181 }
182