digi00x-hwdep.c

  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
 19static 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
 62static __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
 76static 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
 95static 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
107static 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
119static 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
130static 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
148static 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
158int 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}