sound/firewire/motu/motu-hwdep.c

   1 /*
   2  * motu-hwdep.c - a part of driver for MOTU FireWire series
   3  *
   4  * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
   5  *
   6  * Licensed under the terms of the GNU General Public License, version 2.
   7  */
   8
   9 /*
  10  * This codes have five functionalities.
  11  *
  12  * 1.get information about firewire node
  13  * 2.get notification about starting/stopping stream
  14  * 3.lock/unlock streaming
  15  *
  16  */
  17
  18 #include "motu.h"
  19
  20 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
  21                        loff_t *offset)
  22 {
  23         struct snd_motu *motu = hwdep->private_data;
  24         DEFINE_WAIT(wait);
  25         union snd_firewire_event event;
  26
  27         spin_lock_irq(&motu->lock);
  28
  29         while (!motu->dev_lock_changed && motu->msg == 0) {
  30                 prepare_to_wait(&motu->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
  31                 spin_unlock_irq(&motu->lock);
  32                 schedule();
  33                 finish_wait(&motu->hwdep_wait, &wait);
  34                 if (signal_pending(current))
  35                         return -ERESTARTSYS;
  36                 spin_lock_irq(&motu->lock);
  37         }
  38
  39         memset(&event, 0, sizeof(event));
  40         if (motu->dev_lock_changed) {
  41                 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
  42                 event.lock_status.status = (motu->dev_lock_count > 0);
  43                 motu->dev_lock_changed = false;
  44
  45                 count = min_t(long, count, sizeof(event.lock_status));
  46         } else {
  47                 event.motu_notification.type = SNDRV_FIREWIRE_EVENT_MOTU_NOTIFICATION;
  48                 event.motu_notification.message = motu->msg;
  49                 motu->msg = 0;
  50
  51                 count = min_t(long, count, sizeof(event.motu_notification));
  52         }
  53
  54         spin_unlock_irq(&motu->lock);
  55
  56         if (copy_to_user(buf, &event, count))
  57                 return -EFAULT;
  58
  59         return count;
  60 }
  61
  62 static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
  63                                poll_table *wait)
  64 {
  65         struct snd_motu *motu = hwdep->private_data;
  66         __poll_t events;
  67
  68         poll_wait(file, &motu->hwdep_wait, wait);
  69
  70         spin_lock_irq(&motu->lock);
  71         if (motu->dev_lock_changed || motu->msg)
  72                 events = EPOLLIN | EPOLLRDNORM;
  73         else
  74                 events = 0;
  75         spin_unlock_irq(&motu->lock);
  76
  77         return events | EPOLLOUT;
  78 }
  79
  80 static int hwdep_get_info(struct snd_motu *motu, void __user *arg)
  81 {
  82         struct fw_device *dev = fw_parent_device(motu->unit);
  83         struct snd_firewire_get_info info;
  84
  85         memset(&info, 0, sizeof(info));
  86         info.type = SNDRV_FIREWIRE_TYPE_MOTU;
  87         info.card = dev->card->index;
  88         *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
  89         *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
  90         strlcpy(info.device_name, dev_name(&dev->device),
  91                 sizeof(info.device_name));
  92
  93         if (copy_to_user(arg, &info, sizeof(info)))
  94                 return -EFAULT;
  95
  96         return 0;
  97 }
  98
  99 static int hwdep_lock(struct snd_motu *motu)
 100 {
 101         int err;
 102
 103         spin_lock_irq(&motu->lock);
 104
 105         if (motu->dev_lock_count == 0) {
 106                 motu->dev_lock_count = -1;
 107                 err = 0;
 108         } else {
 109                 err = -EBUSY;
 110         }
 111
 112         spin_unlock_irq(&motu->lock);
 113
 114         return err;
 115 }
 116
 117 static int hwdep_unlock(struct snd_motu *motu)
 118 {
 119         int err;
 120
 121         spin_lock_irq(&motu->lock);
 122
 123         if (motu->dev_lock_count == -1) {
 124                 motu->dev_lock_count = 0;
 125                 err = 0;
 126         } else {
 127                 err = -EBADFD;
 128         }
 129
 130         spin_unlock_irq(&motu->lock);
 131
 132         return err;
 133 }
 134
 135 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
 136 {
 137         struct snd_motu *motu = hwdep->private_data;
 138
 139         spin_lock_irq(&motu->lock);
 140         if (motu->dev_lock_count == -1)
 141                 motu->dev_lock_count = 0;
 142         spin_unlock_irq(&motu->lock);
 143
 144         return 0;
 145 }
 146
 147 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
 148             unsigned int cmd, unsigned long arg)
 149 {
 150         struct snd_motu *motu = hwdep->private_data;
 151
 152         switch (cmd) {
 153         case SNDRV_FIREWIRE_IOCTL_GET_INFO:
 154                 return hwdep_get_info(motu, (void __user *)arg);
 155         case SNDRV_FIREWIRE_IOCTL_LOCK:
 156                 return hwdep_lock(motu);
 157         case SNDRV_FIREWIRE_IOCTL_UNLOCK:
 158                 return hwdep_unlock(motu);
 159         default:
 160                 return -ENOIOCTLCMD;
 161         }
 162 }
 163
 164 #ifdef CONFIG_COMPAT
 165 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
 166                               unsigned int cmd, unsigned long arg)
 167 {
 168         return hwdep_ioctl(hwdep, file, cmd,
 169                            (unsigned long)compat_ptr(arg));
 170 }
 171 #else
 172 #define hwdep_compat_ioctl NULL
 173 #endif
 174
 175 int snd_motu_create_hwdep_device(struct snd_motu *motu)
 176 {
 177         static const struct snd_hwdep_ops ops = {
 178                 .read           = hwdep_read,
 179                 .release        = hwdep_release,
 180                 .poll           = hwdep_poll,
 181                 .ioctl          = hwdep_ioctl,
 182                 .ioctl_compat   = hwdep_compat_ioctl,
 183         };
 184         struct snd_hwdep *hwdep;
 185         int err;
 186
 187         err = snd_hwdep_new(motu->card, motu->card->driver, 0, &hwdep);
 188         if (err < 0)
 189                 return err;
 190
 191         strcpy(hwdep->name, "MOTU");
 192         hwdep->iface = SNDRV_HWDEP_IFACE_FW_MOTU;
 193         hwdep->ops = ops;
 194         hwdep->private_data = motu;
 195         hwdep->exclusive = true;
 196
 197         return 0;
 198 }