1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
|
/*
* fireworks_hwdep.c - a part of driver for Fireworks based devices
*
* Copyright (c) 2013-2014 Takashi Sakamoto
*
* Licensed under the terms of the GNU General Public License, version 2.
*/
/*
* This codes have five functionalities.
*
* 1.get information about firewire node
* 2.get notification about starting/stopping stream
* 3.lock/unlock streaming
* 4.transmit command of EFW transaction
* 5.receive response of EFW transaction
*
*/
#include "fireworks.h"
static long
hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained,
loff_t *offset)
{
unsigned int length, till_end, type;
struct snd_efw_transaction *t;
u8 *pull_ptr;
long count = 0;
if (remained < sizeof(type) + sizeof(struct snd_efw_transaction))
return -ENOSPC;
/* data type is SNDRV_FIREWIRE_EVENT_EFW_RESPONSE */
type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE;
if (copy_to_user(buf, &type, sizeof(type)))
return -EFAULT;
remained -= sizeof(type);
buf += sizeof(type);
/* write into buffer as many responses as possible */
spin_lock_irq(&efw->lock);
/*
* When another task reaches here during this task's access to user
* space, it picks up current position in buffer and can read the same
* series of responses.
*/
pull_ptr = efw->pull_ptr;
while (efw->push_ptr != pull_ptr) {
t = (struct snd_efw_transaction *)(pull_ptr);
length = be32_to_cpu(t->length) * sizeof(__be32);
/* confirm enough space for this response */
if (remained < length)
break;
/* copy from ring buffer to user buffer */
while (length > 0) {
till_end = snd_efw_resp_buf_size -
(unsigned int)(pull_ptr - efw->resp_buf);
till_end = min_t(unsigned int, length, till_end);
spin_unlock_irq(&efw->lock);
if (copy_to_user(buf, pull_ptr, till_end))
return -EFAULT;
spin_lock_irq(&efw->lock);
pull_ptr += till_end;
if (pull_ptr >= efw->resp_buf + snd_efw_resp_buf_size)
pull_ptr -= snd_efw_resp_buf_size;
length -= till_end;
buf += till_end;
count += till_end;
remained -= till_end;
}
}
/*
* All of tasks can read from the buffer nearly simultaneously, but the
* last position for each task is different depending on the length of
* given buffer. Here, for simplicity, a position of buffer is set by
* the latest task. It's better for a listening application to allow one
* thread to read from the buffer. Unless, each task can read different
* sequence of responses depending on variation of buffer length.
*/
efw->pull_ptr = pull_ptr;
spin_unlock_irq(&efw->lock);
return count;
}
static long
hwdep_read_locked(struct snd_efw *efw, char __user *buf, long count,
loff_t *offset)
{
union snd_firewire_event event = {
.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
};
spin_lock_irq(&efw->lock);
event.lock_status.status = (efw->dev_lock_count > 0);
efw->dev_lock_changed = false;
spin_unlock_irq(&efw->lock);
count = min_t(long, count, sizeof(event.lock_status));
if (copy_to_user(buf, &event, count))
return -EFAULT;
return count;
}
static long
hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
loff_t *offset)
{
struct snd_efw *efw = hwdep->private_data;
DEFINE_WAIT(wait);
bool dev_lock_changed;
bool queued;
spin_lock_irq(&efw->lock);
dev_lock_changed = efw->dev_lock_changed;
queued = efw->push_ptr != efw->pull_ptr;
while (!dev_lock_changed && !queued) {
prepare_to_wait(&efw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
spin_unlock_irq(&efw->lock);
schedule();
finish_wait(&efw->hwdep_wait, &wait);
if (signal_pending(current))
return -ERESTARTSYS;
spin_lock_irq(&efw->lock);
dev_lock_changed = efw->dev_lock_changed;
queued = efw->push_ptr != efw->pull_ptr;
}
spin_unlock_irq(&efw->lock);
if (dev_lock_changed)
count = hwdep_read_locked(efw, buf, count, offset);
else if (queued)
count = hwdep_read_resp_buf(efw, buf, count, offset);
return count;
}
static long
hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
loff_t *offset)
{
struct snd_efw *efw = hwdep->private_data;
u32 seqnum;
u8 *buf;
if (count < sizeof(struct snd_efw_transaction) ||
SND_EFW_RESPONSE_MAXIMUM_BYTES < count)
return -EINVAL;
buf = memdup_user(data, count);
if (IS_ERR(buf))
return PTR_ERR(buf);
/* check seqnum is not for kernel-land */
seqnum = be32_to_cpu(((struct snd_efw_transaction *)buf)->seqnum);
if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX) {
count = -EINVAL;
goto end;
}
if (snd_efw_transaction_cmd(efw->unit, buf, count) < 0)
count = -EIO;
end:
kfree(buf);
return count;
}
static __poll_t
hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
{
struct snd_efw *efw = hwdep->private_data;
__poll_t events;
poll_wait(file, &efw->hwdep_wait, wait);
spin_lock_irq(&efw->lock);
if (efw->dev_lock_changed || efw->pull_ptr != efw->push_ptr)
events = EPOLLIN | EPOLLRDNORM;
else
events = 0;
spin_unlock_irq(&efw->lock);
return events | EPOLLOUT;
}
static int
hwdep_get_info(struct snd_efw *efw, void __user *arg)
{
struct fw_device *dev = fw_parent_device(efw->unit);
struct snd_firewire_get_info info;
memset(&info, 0, sizeof(info));
info.type = SNDRV_FIREWIRE_TYPE_FIREWORKS;
info.card = dev->card->index;
*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
strlcpy(info.device_name, dev_name(&dev->device),
sizeof(info.device_name));
if (copy_to_user(arg, &info, sizeof(info)))
return -EFAULT;
return 0;
}
static int
hwdep_lock(struct snd_efw *efw)
{
int err;
spin_lock_irq(&efw->lock);
if (efw->dev_lock_count == 0) {
efw->dev_lock_count = -1;
err = 0;
} else {
err = -EBUSY;
}
spin_unlock_irq(&efw->lock);
return err;
}
static int
hwdep_unlock(struct snd_efw *efw)
{
int err;
spin_lock_irq(&efw->lock);
if (efw->dev_lock_count == -1) {
efw->dev_lock_count = 0;
err = 0;
} else {
err = -EBADFD;
}
spin_unlock_irq(&efw->lock);
return err;
}
static int
hwdep_release(struct snd_hwdep *hwdep, struct file *file)
{
struct snd_efw *efw = hwdep->private_data;
spin_lock_irq(&efw->lock);
if (efw->dev_lock_count == -1)
efw->dev_lock_count = 0;
spin_unlock_irq(&efw->lock);
return 0;
}
static int
hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct snd_efw *efw = hwdep->private_data;
switch (cmd) {
case SNDRV_FIREWIRE_IOCTL_GET_INFO:
return hwdep_get_info(efw, (void __user *)arg);
|