1/*
  2 * dice_hwdep.c - a part of driver for DICE based devices
  3 *
  4 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
  5 * Copyright (c) 2014 Takashi Sakamoto <o-takashi@sakamocchi.jp>
  6 *
  7 * Licensed under the terms of the GNU General Public License, version 2.
  8 */
  9
 10#include "dice.h"
 11
 12static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,
 13			    long count, loff_t *offset)
 14{
 15	struct snd_dice *dice = hwdep->private_data;
 16	DEFINE_WAIT(wait);
 17	union snd_firewire_event event;
 18
 19	spin_lock_irq(&dice->lock);
 20
 21	while (!dice->dev_lock_changed && dice->notification_bits == 0) {
 22		prepare_to_wait(&dice->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
 23		spin_unlock_irq(&dice->lock);
 24		schedule();
 25		finish_wait(&dice->hwdep_wait, &wait);
 26		if (signal_pending(current))
 27			return -ERESTARTSYS;
 28		spin_lock_irq(&dice->lock);
 29	}
 30
 31	memset(&event, 0, sizeof(event));
 32	if (dice->dev_lock_changed) {
 33		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
 34		event.lock_status.status = dice->dev_lock_count > 0;
 35		dice->dev_lock_changed = false;
 36
 37		count = min_t(long, count, sizeof(event.lock_status));
 38	} else {
 39		event.dice_notification.type =
 40					SNDRV_FIREWIRE_EVENT_DICE_NOTIFICATION;
 41		event.dice_notification.notification = dice->notification_bits;
 42		dice->notification_bits = 0;
 43
 44		count = min_t(long, count, sizeof(event.dice_notification));
 45	}
 46
 47	spin_unlock_irq(&dice->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_dice *dice = hwdep->private_data;
 59	unsigned int events;
 60
 61	poll_wait(file, &dice->hwdep_wait, wait);
 62
 63	spin_lock_irq(&dice->lock);
 64	if (dice->dev_lock_changed || dice->notification_bits != 0)
 65		events = POLLIN | POLLRDNORM;
 66	else
 67		events = 0;
 68	spin_unlock_irq(&dice->lock);
 69
 70	return events;
 71}
 72
 73static int hwdep_get_info(struct snd_dice *dice, void __user *arg)
 74{
 75	struct fw_device *dev = fw_parent_device(dice->unit);
 76	struct snd_firewire_get_info info;
 77
 78	memset(&info, 0, sizeof(info));
 79	info.type = SNDRV_FIREWIRE_TYPE_DICE;
 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_dice *dice)
 93{
 94	int err;
 95
 96	spin_lock_irq(&dice->lock);
 97
 98	if (dice->dev_lock_count == 0) {
 99		dice->dev_lock_count = -1;
100		err = 0;
101	} else {
102		err = -EBUSY;
103	}
104
105	spin_unlock_irq(&dice->lock);
106
107	return err;
108}
109
110static int hwdep_unlock(struct snd_dice *dice)
111{
112	int err;
113
114	spin_lock_irq(&dice->lock);
115
116	if (dice->dev_lock_count == -1) {
117		dice->dev_lock_count = 0;
118		err = 0;
119	} else {
120		err = -EBADFD;
121	}
122
123	spin_unlock_irq(&dice->lock);
124
125	return err;
126}
127
128static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
129{
130	struct snd_dice *dice = hwdep->private_data;
131
132	spin_lock_irq(&dice->lock);
133	if (dice->dev_lock_count == -1)
134		dice->dev_lock_count = 0;
135	spin_unlock_irq(&dice->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_dice *dice = hwdep->private_data;
144
145	switch (cmd) {
146	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
147		return hwdep_get_info(dice, (void __user *)arg);
148	case SNDRV_FIREWIRE_IOCTL_LOCK:
149		return hwdep_lock(dice);
150	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
151		return hwdep_unlock(dice);
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_dice_create_hwdep(struct snd_dice *dice)
169{
170	static const struct snd_hwdep_ops 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(dice->card, "DICE", 0, &hwdep);
181	if (err < 0)
182		return err;
183	strcpy(hwdep->name, "DICE");
184	hwdep->iface = SNDRV_HWDEP_IFACE_FW_DICE;
185	hwdep->ops = ops;
186	hwdep->private_data = dice;
187	hwdep->exclusive = true;
188
189	return 0;
190}