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
19static 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
55static 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
73static 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
92static 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
110static 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
128static 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
140static 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
158static 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
168int 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;
188end:
189	return err;
190}
191