278 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * tascam-hwdep.c - a part of driver for TASCAM FireWire series4 *5 * Copyright (c) 2015 Takashi Sakamoto6 */7 8/*9 * This codes give three functionality.10 *11 * 1.get firewire node information12 * 2.get notification about starting/stopping stream13 * 3.lock/unlock stream14 */15 16#include "tascam.h"17 18static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,19 long count, loff_t *offset)20 __releases(&tscm->lock)21{22 struct snd_firewire_event_lock_status event = {23 .type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,24 };25 26 event.status = (tscm->dev_lock_count > 0);27 tscm->dev_lock_changed = false;28 count = min_t(long, count, sizeof(event));29 30 spin_unlock_irq(&tscm->lock);31 32 if (copy_to_user(buf, &event, count))33 return -EFAULT;34 35 return count;36}37 38static long tscm_hwdep_read_queue(struct snd_tscm *tscm, char __user *buf,39 long remained, loff_t *offset)40 __releases(&tscm->lock)41{42 char __user *pos = buf;43 unsigned int type = SNDRV_FIREWIRE_EVENT_TASCAM_CONTROL;44 struct snd_firewire_tascam_change *entries = tscm->queue;45 long count;46 47 // At least, one control event can be copied.48 if (remained < sizeof(type) + sizeof(*entries)) {49 spin_unlock_irq(&tscm->lock);50 return -EINVAL;51 }52 53 // Copy the type field later.54 count = sizeof(type);55 remained -= sizeof(type);56 pos += sizeof(type);57 58 while (true) {59 unsigned int head_pos;60 unsigned int tail_pos;61 unsigned int length;62 63 if (tscm->pull_pos == tscm->push_pos)64 break;65 else if (tscm->pull_pos < tscm->push_pos)66 tail_pos = tscm->push_pos;67 else68 tail_pos = SND_TSCM_QUEUE_COUNT;69 head_pos = tscm->pull_pos;70 71 length = (tail_pos - head_pos) * sizeof(*entries);72 if (remained < length)73 length = rounddown(remained, sizeof(*entries));74 if (length == 0)75 break;76 77 spin_unlock_irq(&tscm->lock);78 if (copy_to_user(pos, &entries[head_pos], length))79 return -EFAULT;80 81 spin_lock_irq(&tscm->lock);82 83 tscm->pull_pos = tail_pos % SND_TSCM_QUEUE_COUNT;84 85 count += length;86 remained -= length;87 pos += length;88 }89 90 spin_unlock_irq(&tscm->lock);91 92 if (copy_to_user(buf, &type, sizeof(type)))93 return -EFAULT;94 95 return count;96}97 98static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,99 loff_t *offset)100{101 struct snd_tscm *tscm = hwdep->private_data;102 DEFINE_WAIT(wait);103 104 spin_lock_irq(&tscm->lock);105 106 while (!tscm->dev_lock_changed && tscm->push_pos == tscm->pull_pos) {107 prepare_to_wait(&tscm->hwdep_wait, &wait, TASK_INTERRUPTIBLE);108 spin_unlock_irq(&tscm->lock);109 schedule();110 finish_wait(&tscm->hwdep_wait, &wait);111 if (signal_pending(current))112 return -ERESTARTSYS;113 spin_lock_irq(&tscm->lock);114 }115 116 // NOTE: The acquired lock should be released in callee side.117 if (tscm->dev_lock_changed) {118 count = tscm_hwdep_read_locked(tscm, buf, count, offset);119 } else if (tscm->push_pos != tscm->pull_pos) {120 count = tscm_hwdep_read_queue(tscm, buf, count, offset);121 } else {122 spin_unlock_irq(&tscm->lock);123 count = 0;124 }125 126 return count;127}128 129static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,130 poll_table *wait)131{132 struct snd_tscm *tscm = hwdep->private_data;133 __poll_t events;134 135 poll_wait(file, &tscm->hwdep_wait, wait);136 137 spin_lock_irq(&tscm->lock);138 if (tscm->dev_lock_changed || tscm->push_pos != tscm->pull_pos)139 events = EPOLLIN | EPOLLRDNORM;140 else141 events = 0;142 spin_unlock_irq(&tscm->lock);143 144 return events;145}146 147static int hwdep_get_info(struct snd_tscm *tscm, void __user *arg)148{149 struct fw_device *dev = fw_parent_device(tscm->unit);150 struct snd_firewire_get_info info;151 152 memset(&info, 0, sizeof(info));153 info.type = SNDRV_FIREWIRE_TYPE_TASCAM;154 info.card = dev->card->index;155 *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);156 *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);157 strscpy(info.device_name, dev_name(&dev->device),158 sizeof(info.device_name));159 160 if (copy_to_user(arg, &info, sizeof(info)))161 return -EFAULT;162 163 return 0;164}165 166static int hwdep_lock(struct snd_tscm *tscm)167{168 int err;169 170 spin_lock_irq(&tscm->lock);171 172 if (tscm->dev_lock_count == 0) {173 tscm->dev_lock_count = -1;174 err = 0;175 } else {176 err = -EBUSY;177 }178 179 spin_unlock_irq(&tscm->lock);180 181 return err;182}183 184static int hwdep_unlock(struct snd_tscm *tscm)185{186 int err;187 188 spin_lock_irq(&tscm->lock);189 190 if (tscm->dev_lock_count == -1) {191 tscm->dev_lock_count = 0;192 err = 0;193 } else {194 err = -EBADFD;195 }196 197 spin_unlock_irq(&tscm->lock);198 199 return err;200}201 202static int tscm_hwdep_state(struct snd_tscm *tscm, void __user *arg)203{204 if (copy_to_user(arg, tscm->state, sizeof(tscm->state)))205 return -EFAULT;206 207 return 0;208}209 210static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)211{212 struct snd_tscm *tscm = hwdep->private_data;213 214 spin_lock_irq(&tscm->lock);215 if (tscm->dev_lock_count == -1)216 tscm->dev_lock_count = 0;217 spin_unlock_irq(&tscm->lock);218 219 return 0;220}221 222static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,223 unsigned int cmd, unsigned long arg)224{225 struct snd_tscm *tscm = hwdep->private_data;226 227 switch (cmd) {228 case SNDRV_FIREWIRE_IOCTL_GET_INFO:229 return hwdep_get_info(tscm, (void __user *)arg);230 case SNDRV_FIREWIRE_IOCTL_LOCK:231 return hwdep_lock(tscm);232 case SNDRV_FIREWIRE_IOCTL_UNLOCK:233 return hwdep_unlock(tscm);234 case SNDRV_FIREWIRE_IOCTL_TASCAM_STATE:235 return tscm_hwdep_state(tscm, (void __user *)arg);236 default:237 return -ENOIOCTLCMD;238 }239}240 241#ifdef CONFIG_COMPAT242static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,243 unsigned int cmd, unsigned long arg)244{245 return hwdep_ioctl(hwdep, file, cmd,246 (unsigned long)compat_ptr(arg));247}248#else249#define hwdep_compat_ioctl NULL250#endif251 252int snd_tscm_create_hwdep_device(struct snd_tscm *tscm)253{254 static const struct snd_hwdep_ops ops = {255 .read = hwdep_read,256 .release = hwdep_release,257 .poll = hwdep_poll,258 .ioctl = hwdep_ioctl,259 .ioctl_compat = hwdep_compat_ioctl,260 };261 struct snd_hwdep *hwdep;262 int err;263 264 err = snd_hwdep_new(tscm->card, "Tascam", 0, &hwdep);265 if (err < 0)266 return err;267 268 strcpy(hwdep->name, "Tascam");269 hwdep->iface = SNDRV_HWDEP_IFACE_FW_TASCAM;270 hwdep->ops = ops;271 hwdep->private_data = tscm;272 hwdep->exclusive = true;273 274 tscm->hwdep = hwdep;275 276 return err;277}278