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 remained -= sizeof(type);
40 /* write into buffer as many responses as possible */
41 spin_lock_irq(&efw->lock);
44 * When another task reaches here during this task's access to user
45 * space, it picks up current position in buffer and can read the same
46 * series of responses.
48 pull_ptr = efw->pull_ptr;
50 while (efw->push_ptr != pull_ptr) {
51 t = (struct snd_efw_transaction *)(pull_ptr);
52 length = be32_to_cpu(t->length) * sizeof(__be32);
54 /* confirm enough space for this response */
55 if (remained < length)
58 /* copy from ring buffer to user buffer */
60 till_end = snd_efw_resp_buf_size -
61 (unsigned int)(pull_ptr - efw->resp_buf);
62 till_end = min_t(unsigned int, length, till_end);
64 spin_unlock_irq(&efw->lock);
66 if (copy_to_user(buf, pull_ptr, till_end))
69 spin_lock_irq(&efw->lock);
72 if (pull_ptr >= efw->resp_buf + snd_efw_resp_buf_size)
73 pull_ptr -= snd_efw_resp_buf_size;
83 * All of tasks can read from the buffer nearly simultaneously, but the
84 * last position for each task is different depending on the length of
85 * given buffer. Here, for simplicity, a position of buffer is set by
86 * the latest task. It's better for a listening application to allow one
87 * thread to read from the buffer. Unless, each task can read different
88 * sequence of responses depending on variation of buffer length.
90 efw->pull_ptr = pull_ptr;
92 spin_unlock_irq(&efw->lock);
98 hwdep_read_locked(struct snd_efw *efw, char __user *buf, long count,
101 union snd_firewire_event event = {
102 .lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
105 spin_lock_irq(&efw->lock);
107 event.lock_status.status = (efw->dev_lock_count > 0);
108 efw->dev_lock_changed = false;
110 spin_unlock_irq(&efw->lock);
112 count = min_t(long, count, sizeof(event.lock_status));
114 if (copy_to_user(buf, &event, count))
121 hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
124 struct snd_efw *efw = hwdep->private_data;
126 bool dev_lock_changed;
129 spin_lock_irq(&efw->lock);
131 dev_lock_changed = efw->dev_lock_changed;
132 queued = efw->push_ptr != efw->pull_ptr;
134 while (!dev_lock_changed && !queued) {
135 prepare_to_wait(&efw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
136 spin_unlock_irq(&efw->lock);
138 finish_wait(&efw->hwdep_wait, &wait);
139 if (signal_pending(current))
141 spin_lock_irq(&efw->lock);
142 dev_lock_changed = efw->dev_lock_changed;
143 queued = efw->push_ptr != efw->pull_ptr;
146 spin_unlock_irq(&efw->lock);
148 if (dev_lock_changed)
149 count = hwdep_read_locked(efw, buf, count, offset);
151 count = hwdep_read_resp_buf(efw, buf, count, offset);
157 hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
160 struct snd_efw *efw = hwdep->private_data;
164 if (count < sizeof(struct snd_efw_transaction) ||
165 SND_EFW_RESPONSE_MAXIMUM_BYTES < count)
168 buf = memdup_user(data, count);
172 /* check seqnum is not for kernel-land */
173 seqnum = be32_to_cpu(((struct snd_efw_transaction *)buf)->seqnum);
174 if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX) {
179 if (snd_efw_transaction_cmd(efw->unit, buf, count) < 0)
187 hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
189 struct snd_efw *efw = hwdep->private_data;
192 poll_wait(file, &efw->hwdep_wait, wait);
194 spin_lock_irq(&efw->lock);
195 if (efw->dev_lock_changed || efw->pull_ptr != efw->push_ptr)
196 events = EPOLLIN | EPOLLRDNORM;
199 spin_unlock_irq(&efw->lock);
201 return events | EPOLLOUT;
205 hwdep_get_info(struct snd_efw *efw, void __user *arg)
207 struct fw_device *dev = fw_parent_device(efw->unit);
208 struct snd_firewire_get_info info;
210 memset(&info, 0, sizeof(info));
211 info.type = SNDRV_FIREWIRE_TYPE_FIREWORKS;
212 info.card = dev->card->index;
213 *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
214 *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
215 strlcpy(info.device_name, dev_name(&dev->device),
216 sizeof(info.device_name));
218 if (copy_to_user(arg, &info, sizeof(info)))
225 hwdep_lock(struct snd_efw *efw)
229 spin_lock_irq(&efw->lock);
231 if (efw->dev_lock_count == 0) {
232 efw->dev_lock_count = -1;
238 spin_unlock_irq(&efw->lock);
244 hwdep_unlock(struct snd_efw *efw)
248 spin_lock_irq(&efw->lock);
250 if (efw->dev_lock_count == -1) {
251 efw->dev_lock_count = 0;
257 spin_unlock_irq(&efw->lock);
263 hwdep_release(struct snd_hwdep *hwdep, struct file *file)
265 struct snd_efw *efw = hwdep->private_data;
267 spin_lock_irq(&efw->lock);
268 if (efw->dev_lock_count == -1)
269 efw->dev_lock_count = 0;
270 spin_unlock_irq(&efw->lock);
276 hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
277 unsigned int cmd, unsigned long arg)
279 struct snd_efw *efw = hwdep->private_data;
282 case SNDRV_FIREWIRE_IOCTL_GET_INFO:
283 return hwdep_get_info(efw, (void __user *)arg);
284 case SNDRV_FIREWIRE_IOCTL_LOCK:
285 return hwdep_lock(efw);
286 case SNDRV_FIREWIRE_IOCTL_UNLOCK:
287 return hwdep_unlock(efw);
295 hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
296 unsigned int cmd, unsigned long arg)
298 return hwdep_ioctl(hwdep, file, cmd,
299 (unsigned long)compat_ptr(arg));
302 #define hwdep_compat_ioctl NULL
305 int snd_efw_create_hwdep_device(struct snd_efw *efw)
307 static const struct snd_hwdep_ops ops = {
309 .write = hwdep_write,
310 .release = hwdep_release,
312 .ioctl = hwdep_ioctl,
313 .ioctl_compat = hwdep_compat_ioctl,
315 struct snd_hwdep *hwdep;
318 err = snd_hwdep_new(efw->card, "Fireworks", 0, &hwdep);
321 strcpy(hwdep->name, "Fireworks");
322 hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREWORKS;
324 hwdep->private_data = efw;
325 hwdep->exclusive = true;