1 // SPDX-License-Identifier: GPL-2.0-only
3 * fireworks_hwdep.c - a part of driver for Fireworks based devices
5 * Copyright (c) 2013-2014 Takashi Sakamoto
9 * This codes have five functionalities.
11 * 1.get information about firewire node
12 * 2.get notification about starting/stopping stream
13 * 3.lock/unlock streaming
14 * 4.transmit command of EFW transaction
15 * 5.receive response of EFW transaction
19 #include "fireworks.h"
22 hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained,
25 unsigned int length, till_end, type;
26 struct snd_efw_transaction *t;
30 if (remained < sizeof(type) + sizeof(struct snd_efw_transaction))
33 /* data type is SNDRV_FIREWIRE_EVENT_EFW_RESPONSE */
34 type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE;
35 if (copy_to_user(buf, &type, sizeof(type)))
37 count += sizeof(type);
38 remained -= sizeof(type);
41 /* write into buffer as many responses as possible */
42 spin_lock_irq(&efw->lock);
45 * When another task reaches here during this task's access to user
46 * space, it picks up current position in buffer and can read the same
47 * series of responses.
49 pull_ptr = efw->pull_ptr;
51 while (efw->push_ptr != pull_ptr) {
52 t = (struct snd_efw_transaction *)(pull_ptr);
53 length = be32_to_cpu(t->length) * sizeof(__be32);
55 /* confirm enough space for this response */
56 if (remained < length)
59 /* copy from ring buffer to user buffer */
61 till_end = snd_efw_resp_buf_size -
62 (unsigned int)(pull_ptr - efw->resp_buf);
63 till_end = min_t(unsigned int, length, till_end);
65 spin_unlock_irq(&efw->lock);
67 if (copy_to_user(buf, pull_ptr, till_end))
70 spin_lock_irq(&efw->lock);
73 if (pull_ptr >= efw->resp_buf + snd_efw_resp_buf_size)
74 pull_ptr -= snd_efw_resp_buf_size;
84 * All of tasks can read from the buffer nearly simultaneously, but the
85 * last position for each task is different depending on the length of
86 * given buffer. Here, for simplicity, a position of buffer is set by
87 * the latest task. It's better for a listening application to allow one
88 * thread to read from the buffer. Unless, each task can read different
89 * sequence of responses depending on variation of buffer length.
91 efw->pull_ptr = pull_ptr;
93 spin_unlock_irq(&efw->lock);
99 hwdep_read_locked(struct snd_efw *efw, char __user *buf, long count,
102 union snd_firewire_event event = {
103 .lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
106 spin_lock_irq(&efw->lock);
108 event.lock_status.status = (efw->dev_lock_count > 0);
109 efw->dev_lock_changed = false;
111 spin_unlock_irq(&efw->lock);
113 count = min_t(long, count, sizeof(event.lock_status));
115 if (copy_to_user(buf, &event, count))
122 hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
125 struct snd_efw *efw = hwdep->private_data;
127 bool dev_lock_changed;
130 spin_lock_irq(&efw->lock);
132 dev_lock_changed = efw->dev_lock_changed;
133 queued = efw->push_ptr != efw->pull_ptr;
135 while (!dev_lock_changed && !queued) {
136 prepare_to_wait(&efw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
137 spin_unlock_irq(&efw->lock);
139 finish_wait(&efw->hwdep_wait, &wait);
140 if (signal_pending(current))
142 spin_lock_irq(&efw->lock);
143 dev_lock_changed = efw->dev_lock_changed;
144 queued = efw->push_ptr != efw->pull_ptr;
147 spin_unlock_irq(&efw->lock);
149 if (dev_lock_changed)
150 count = hwdep_read_locked(efw, buf, count, offset);
152 count = hwdep_read_resp_buf(efw, buf, count, offset);
158 hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
161 struct snd_efw *efw = hwdep->private_data;
165 if (count < sizeof(struct snd_efw_transaction) ||
166 SND_EFW_RESPONSE_MAXIMUM_BYTES < count)
169 buf = memdup_user(data, count);
173 /* check seqnum is not for kernel-land */
174 seqnum = be32_to_cpu(((struct snd_efw_transaction *)buf)->seqnum);
175 if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX) {
180 if (snd_efw_transaction_cmd(efw->unit, buf, count) < 0)
188 hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
190 struct snd_efw *efw = hwdep->private_data;
193 poll_wait(file, &efw->hwdep_wait, wait);
195 spin_lock_irq(&efw->lock);
196 if (efw->dev_lock_changed || efw->pull_ptr != efw->push_ptr)
197 events = EPOLLIN | EPOLLRDNORM;
200 spin_unlock_irq(&efw->lock);
202 return events | EPOLLOUT;
206 hwdep_get_info(struct snd_efw *efw, void __user *arg)
208 struct fw_device *dev = fw_parent_device(efw->unit);
209 struct snd_firewire_get_info info;
211 memset(&info, 0, sizeof(info));
212 info.type = SNDRV_FIREWIRE_TYPE_FIREWORKS;
213 info.card = dev->card->index;
214 *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
215 *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
216 strscpy(info.device_name, dev_name(&dev->device),
217 sizeof(info.device_name));
219 if (copy_to_user(arg, &info, sizeof(info)))
226 hwdep_lock(struct snd_efw *efw)
230 spin_lock_irq(&efw->lock);
232 if (efw->dev_lock_count == 0) {
233 efw->dev_lock_count = -1;
239 spin_unlock_irq(&efw->lock);
245 hwdep_unlock(struct snd_efw *efw)
249 spin_lock_irq(&efw->lock);
251 if (efw->dev_lock_count == -1) {
252 efw->dev_lock_count = 0;
258 spin_unlock_irq(&efw->lock);
264 hwdep_release(struct snd_hwdep *hwdep, struct file *file)
266 struct snd_efw *efw = hwdep->private_data;
268 spin_lock_irq(&efw->lock);
269 if (efw->dev_lock_count == -1)
270 efw->dev_lock_count = 0;
271 spin_unlock_irq(&efw->lock);
277 hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
278 unsigned int cmd, unsigned long arg)
280 struct snd_efw *efw = hwdep->private_data;
283 case SNDRV_FIREWIRE_IOCTL_GET_INFO:
284 return hwdep_get_info(efw, (void __user *)arg);
285 case SNDRV_FIREWIRE_IOCTL_LOCK:
286 return hwdep_lock(efw);
287 case SNDRV_FIREWIRE_IOCTL_UNLOCK:
288 return hwdep_unlock(efw);
296 hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
297 unsigned int cmd, unsigned long arg)
299 return hwdep_ioctl(hwdep, file, cmd,
300 (unsigned long)compat_ptr(arg));
303 #define hwdep_compat_ioctl NULL
306 int snd_efw_create_hwdep_device(struct snd_efw *efw)
308 static const struct snd_hwdep_ops ops = {
310 .write = hwdep_write,
311 .release = hwdep_release,
313 .ioctl = hwdep_ioctl,
314 .ioctl_compat = hwdep_compat_ioctl,
316 struct snd_hwdep *hwdep;
319 err = snd_hwdep_new(efw->card, "Fireworks", 0, &hwdep);
322 strcpy(hwdep->name, "Fireworks");
323 hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREWORKS;
325 hwdep->private_data = efw;
326 hwdep->exclusive = true;