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 
hwdep_read(struct snd_hwdep * hwdep,char __user * buf,long count,loff_t * offset)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 
hwdep_poll(struct snd_hwdep * hwdep,struct file * file,poll_table * wait)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 	__poll_t events;
67 
68 	poll_wait(file, &dg00x->hwdep_wait, wait);
69 
70 	spin_lock_irq(&dg00x->lock);
71 	if (dg00x->dev_lock_changed || dg00x->msg)
72 		events = EPOLLIN | EPOLLRDNORM;
73 	else
74 		events = 0;
75 	spin_unlock_irq(&dg00x->lock);
76 
77 	return events;
78 }
79 
hwdep_get_info(struct snd_dg00x * dg00x,void __user * arg)80 static int hwdep_get_info(struct snd_dg00x *dg00x, void __user *arg)
81 {
82 	struct fw_device *dev = fw_parent_device(dg00x->unit);
83 	struct snd_firewire_get_info info;
84 
85 	memset(&info, 0, sizeof(info));
86 	info.type = SNDRV_FIREWIRE_TYPE_DIGI00X;
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 	strscpy(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 
hwdep_lock(struct snd_dg00x * dg00x)99 static int hwdep_lock(struct snd_dg00x *dg00x)
100 {
101 	int err;
102 
103 	spin_lock_irq(&dg00x->lock);
104 
105 	if (dg00x->dev_lock_count == 0) {
106 		dg00x->dev_lock_count = -1;
107 		err = 0;
108 	} else {
109 		err = -EBUSY;
110 	}
111 
112 	spin_unlock_irq(&dg00x->lock);
113 
114 	return err;
115 }
116 
hwdep_unlock(struct snd_dg00x * dg00x)117 static int hwdep_unlock(struct snd_dg00x *dg00x)
118 {
119 	int err;
120 
121 	spin_lock_irq(&dg00x->lock);
122 
123 	if (dg00x->dev_lock_count == -1) {
124 		dg00x->dev_lock_count = 0;
125 		err = 0;
126 	} else {
127 		err = -EBADFD;
128 	}
129 
130 	spin_unlock_irq(&dg00x->lock);
131 
132 	return err;
133 }
134 
hwdep_release(struct snd_hwdep * hwdep,struct file * file)135 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
136 {
137 	struct snd_dg00x *dg00x = hwdep->private_data;
138 
139 	spin_lock_irq(&dg00x->lock);
140 	if (dg00x->dev_lock_count == -1)
141 		dg00x->dev_lock_count = 0;
142 	spin_unlock_irq(&dg00x->lock);
143 
144 	return 0;
145 }
146 
hwdep_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)147 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
148 	    unsigned int cmd, unsigned long arg)
149 {
150 	struct snd_dg00x *dg00x = hwdep->private_data;
151 
152 	switch (cmd) {
153 	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
154 		return hwdep_get_info(dg00x, (void __user *)arg);
155 	case SNDRV_FIREWIRE_IOCTL_LOCK:
156 		return hwdep_lock(dg00x);
157 	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
158 		return hwdep_unlock(dg00x);
159 	default:
160 		return -ENOIOCTLCMD;
161 	}
162 }
163 
164 #ifdef CONFIG_COMPAT
hwdep_compat_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)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 
snd_dg00x_create_hwdep_device(struct snd_dg00x * dg00x)175 int snd_dg00x_create_hwdep_device(struct snd_dg00x *dg00x)
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(dg00x->card, "Digi00x", 0, &hwdep);
188 	if (err < 0)
189 		return err;
190 
191 	strcpy(hwdep->name, "Digi00x");
192 	hwdep->iface = SNDRV_HWDEP_IFACE_FW_DIGI00X;
193 	hwdep->ops = ops;
194 	hwdep->private_data = dg00x;
195 	hwdep->exclusive = true;
196 
197 	return err;
198 }
199