1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * motu-hwdep.c - a part of driver for MOTU FireWire series
4  *
5  * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
6  */
7 
8 /*
9  * This codes have five functionalities.
10  *
11  * 1.get information about firewire node
12  * 2.get notification about starting/stopping stream
13  * 3.lock/unlock streaming
14  *
15  */
16 
17 #include "motu.h"
18 
has_dsp_event(struct snd_motu * motu)19 static bool has_dsp_event(struct snd_motu *motu)
20 {
21 	if (motu->spec->flags & SND_MOTU_SPEC_REGISTER_DSP)
22 		return (snd_motu_register_dsp_message_parser_count_event(motu) > 0);
23 	else
24 		return false;
25 }
26 
hwdep_read(struct snd_hwdep * hwdep,char __user * buf,long count,loff_t * offset)27 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
28 		       loff_t *offset)
29 {
30 	struct snd_motu *motu = hwdep->private_data;
31 	DEFINE_WAIT(wait);
32 	union snd_firewire_event event;
33 
34 	spin_lock_irq(&motu->lock);
35 
36 	while (!motu->dev_lock_changed && motu->msg == 0 && !has_dsp_event(motu)) {
37 		prepare_to_wait(&motu->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
38 		spin_unlock_irq(&motu->lock);
39 		schedule();
40 		finish_wait(&motu->hwdep_wait, &wait);
41 		if (signal_pending(current))
42 			return -ERESTARTSYS;
43 		spin_lock_irq(&motu->lock);
44 	}
45 
46 	memset(&event, 0, sizeof(event));
47 	if (motu->dev_lock_changed) {
48 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
49 		event.lock_status.status = (motu->dev_lock_count > 0);
50 		motu->dev_lock_changed = false;
51 		spin_unlock_irq(&motu->lock);
52 
53 		count = min_t(long, count, sizeof(event));
54 		if (copy_to_user(buf, &event, count))
55 			return -EFAULT;
56 	} else if (motu->msg > 0) {
57 		event.motu_notification.type = SNDRV_FIREWIRE_EVENT_MOTU_NOTIFICATION;
58 		event.motu_notification.message = motu->msg;
59 		motu->msg = 0;
60 		spin_unlock_irq(&motu->lock);
61 
62 		count = min_t(long, count, sizeof(event));
63 		if (copy_to_user(buf, &event, count))
64 			return -EFAULT;
65 	} else if (has_dsp_event(motu)) {
66 		size_t consumed = 0;
67 		u32 __user *ptr;
68 		u32 ev;
69 
70 		spin_unlock_irq(&motu->lock);
71 
72 		// Header is filled later.
73 		consumed += sizeof(event.motu_register_dsp_change);
74 
75 		while (consumed < count &&
76 		       snd_motu_register_dsp_message_parser_copy_event(motu, &ev)) {
77 			ptr = (u32 __user *)(buf + consumed);
78 			if (put_user(ev, ptr))
79 				return -EFAULT;
80 			consumed += sizeof(ev);
81 		}
82 
83 		event.motu_register_dsp_change.type = SNDRV_FIREWIRE_EVENT_MOTU_REGISTER_DSP_CHANGE;
84 		event.motu_register_dsp_change.count =
85 			(consumed - sizeof(event.motu_register_dsp_change)) / 4;
86 		if (copy_to_user(buf, &event, sizeof(event.motu_register_dsp_change)))
87 			return -EFAULT;
88 
89 		count = consumed;
90 	}
91 
92 	return count;
93 }
94 
hwdep_poll(struct snd_hwdep * hwdep,struct file * file,poll_table * wait)95 static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
96 			       poll_table *wait)
97 {
98 	struct snd_motu *motu = hwdep->private_data;
99 	__poll_t events;
100 
101 	poll_wait(file, &motu->hwdep_wait, wait);
102 
103 	spin_lock_irq(&motu->lock);
104 	if (motu->dev_lock_changed || motu->msg || has_dsp_event(motu))
105 		events = EPOLLIN | EPOLLRDNORM;
106 	else
107 		events = 0;
108 	spin_unlock_irq(&motu->lock);
109 
110 	return events | EPOLLOUT;
111 }
112 
hwdep_get_info(struct snd_motu * motu,void __user * arg)113 static int hwdep_get_info(struct snd_motu *motu, void __user *arg)
114 {
115 	struct fw_device *dev = fw_parent_device(motu->unit);
116 	struct snd_firewire_get_info info;
117 
118 	memset(&info, 0, sizeof(info));
119 	info.type = SNDRV_FIREWIRE_TYPE_MOTU;
120 	info.card = dev->card->index;
121 	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
122 	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
123 	strscpy(info.device_name, dev_name(&dev->device),
124 		sizeof(info.device_name));
125 
126 	if (copy_to_user(arg, &info, sizeof(info)))
127 		return -EFAULT;
128 
129 	return 0;
130 }
131 
hwdep_lock(struct snd_motu * motu)132 static int hwdep_lock(struct snd_motu *motu)
133 {
134 	int err;
135 
136 	spin_lock_irq(&motu->lock);
137 
138 	if (motu->dev_lock_count == 0) {
139 		motu->dev_lock_count = -1;
140 		err = 0;
141 	} else {
142 		err = -EBUSY;
143 	}
144 
145 	spin_unlock_irq(&motu->lock);
146 
147 	return err;
148 }
149 
hwdep_unlock(struct snd_motu * motu)150 static int hwdep_unlock(struct snd_motu *motu)
151 {
152 	int err;
153 
154 	spin_lock_irq(&motu->lock);
155 
156 	if (motu->dev_lock_count == -1) {
157 		motu->dev_lock_count = 0;
158 		err = 0;
159 	} else {
160 		err = -EBADFD;
161 	}
162 
163 	spin_unlock_irq(&motu->lock);
164 
165 	return err;
166 }
167 
hwdep_release(struct snd_hwdep * hwdep,struct file * file)168 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
169 {
170 	struct snd_motu *motu = hwdep->private_data;
171 
172 	spin_lock_irq(&motu->lock);
173 	if (motu->dev_lock_count == -1)
174 		motu->dev_lock_count = 0;
175 	spin_unlock_irq(&motu->lock);
176 
177 	return 0;
178 }
179 
hwdep_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)180 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
181 	    unsigned int cmd, unsigned long arg)
182 {
183 	struct snd_motu *motu = hwdep->private_data;
184 
185 	switch (cmd) {
186 	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
187 		return hwdep_get_info(motu, (void __user *)arg);
188 	case SNDRV_FIREWIRE_IOCTL_LOCK:
189 		return hwdep_lock(motu);
190 	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
191 		return hwdep_unlock(motu);
192 	case SNDRV_FIREWIRE_IOCTL_MOTU_REGISTER_DSP_METER:
193 	{
194 		struct snd_firewire_motu_register_dsp_meter *meter;
195 		int err;
196 
197 		if (!(motu->spec->flags & SND_MOTU_SPEC_REGISTER_DSP))
198 			return -ENXIO;
199 
200 		meter = kzalloc(sizeof(*meter), GFP_KERNEL);
201 		if (!meter)
202 			return -ENOMEM;
203 
204 		snd_motu_register_dsp_message_parser_copy_meter(motu, meter);
205 
206 		err = copy_to_user((void __user *)arg, meter, sizeof(*meter));
207 		kfree(meter);
208 
209 		if (err)
210 			return -EFAULT;
211 
212 		return 0;
213 	}
214 	case SNDRV_FIREWIRE_IOCTL_MOTU_COMMAND_DSP_METER:
215 	{
216 		struct snd_firewire_motu_command_dsp_meter *meter;
217 		int err;
218 
219 		if (!(motu->spec->flags & SND_MOTU_SPEC_COMMAND_DSP))
220 			return -ENXIO;
221 
222 		meter = kzalloc(sizeof(*meter), GFP_KERNEL);
223 		if (!meter)
224 			return -ENOMEM;
225 
226 		snd_motu_command_dsp_message_parser_copy_meter(motu, meter);
227 
228 		err = copy_to_user((void __user *)arg, meter, sizeof(*meter));
229 		kfree(meter);
230 
231 		if (err)
232 			return -EFAULT;
233 
234 		return 0;
235 	}
236 	case SNDRV_FIREWIRE_IOCTL_MOTU_REGISTER_DSP_PARAMETER:
237 	{
238 		struct snd_firewire_motu_register_dsp_parameter *param;
239 		int err;
240 
241 		if (!(motu->spec->flags & SND_MOTU_SPEC_REGISTER_DSP))
242 			return -ENXIO;
243 
244 		param = kzalloc(sizeof(*param), GFP_KERNEL);
245 		if (!param)
246 			return -ENOMEM;
247 
248 		snd_motu_register_dsp_message_parser_copy_parameter(motu, param);
249 
250 		err = copy_to_user((void __user *)arg, param, sizeof(*param));
251 		kfree(param);
252 		if (err)
253 			return -EFAULT;
254 
255 		return 0;
256 	}
257 	default:
258 		return -ENOIOCTLCMD;
259 	}
260 }
261 
262 #ifdef CONFIG_COMPAT
hwdep_compat_ioctl(struct snd_hwdep * hwdep,struct file * file,unsigned int cmd,unsigned long arg)263 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
264 			      unsigned int cmd, unsigned long arg)
265 {
266 	return hwdep_ioctl(hwdep, file, cmd,
267 			   (unsigned long)compat_ptr(arg));
268 }
269 #else
270 #define hwdep_compat_ioctl NULL
271 #endif
272 
snd_motu_create_hwdep_device(struct snd_motu * motu)273 int snd_motu_create_hwdep_device(struct snd_motu *motu)
274 {
275 	static const struct snd_hwdep_ops ops = {
276 		.read		= hwdep_read,
277 		.release	= hwdep_release,
278 		.poll		= hwdep_poll,
279 		.ioctl		= hwdep_ioctl,
280 		.ioctl_compat	= hwdep_compat_ioctl,
281 	};
282 	struct snd_hwdep *hwdep;
283 	int err;
284 
285 	err = snd_hwdep_new(motu->card, motu->card->driver, 0, &hwdep);
286 	if (err < 0)
287 		return err;
288 
289 	strcpy(hwdep->name, "MOTU");
290 	hwdep->iface = SNDRV_HWDEP_IFACE_FW_MOTU;
291 	hwdep->ops = ops;
292 	hwdep->private_data = motu;
293 	hwdep->exclusive = true;
294 
295 	motu->hwdep = hwdep;
296 
297 	return 0;
298 }
299