kernel/sound/firewire/dice/dice-hwdep.c

   1 /*
   2  * dice_hwdep.c - a part of driver for DICE based devices
   3  *
   4  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
   5  * Copyright (c) 2014 Takashi Sakamoto <o-takashi@sakamocchi.jp>
   6  *
   7  * Licensed under the terms of the GNU General Public License, version 2.
   8  */
   9
  10 #include "dice.h"
  11
  12 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,
  13                             long count, loff_t *offset)
  14 {
  15         struct snd_dice *dice = hwdep->private_data;
  16         DEFINE_WAIT(wait);
  17         union snd_firewire_event event;
  18
  19         spin_lock_irq(&dice->lock);
  20
  21         while (!dice->dev_lock_changed && dice->notification_bits == 0) {
  22                 prepare_to_wait(&dice->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
  23                 spin_unlock_irq(&dice->lock);
  24                 schedule();
  25                 finish_wait(&dice->hwdep_wait, &wait);
  26                 if (signal_pending(current))
  27                         return -ERESTARTSYS;
  28                 spin_lock_irq(&dice->lock);
  29         }
  30
  31         memset(&event, 0, sizeof(event));
  32         if (dice->dev_lock_changed) {
  33                 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
  34                 event.lock_status.status = dice->dev_lock_count > 0;
  35                 dice->dev_lock_changed = false;
  36
  37                 count = min_t(long, count, sizeof(event.lock_status));
  38         } else {
  39                 event.dice_notification.type =
  40                                         SNDRV_FIREWIRE_EVENT_DICE_NOTIFICATION;
  41                 event.dice_notification.notification = dice->notification_bits;
  42                 dice->notification_bits = 0;
  43
  44                 count = min_t(long, count, sizeof(event.dice_notification));
  45         }
  46
  47         spin_unlock_irq(&dice->lock);
  48
  49         if (copy_to_user(buf, &event, count))
  50                 return -EFAULT;
  51
  52         return count;
  53 }
  54
  55 static unsigned int hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
  56                                poll_table *wait)
  57 {
  58         struct snd_dice *dice = hwdep->private_data;
  59         unsigned int events;
  60
  61         poll_wait(file, &dice->hwdep_wait, wait);
  62
  63         spin_lock_irq(&dice->lock);
  64         if (dice->dev_lock_changed || dice->notification_bits != 0)
  65                 events = POLLIN | POLLRDNORM;
  66         else
  67                 events = 0;
  68         spin_unlock_irq(&dice->lock);
  69
  70         return events;
  71 }
  72
  73 static int hwdep_get_info(struct snd_dice *dice, void __user *arg)
  74 {
  75         struct fw_device *dev = fw_parent_device(dice->unit);
  76         struct snd_firewire_get_info info;
  77
  78         memset(&info, 0, sizeof(info));
  79         info.type = SNDRV_FIREWIRE_TYPE_DICE;
  80         info.card = dev->card->index;
  81         *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
  82         *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
  83         strlcpy(info.device_name, dev_name(&dev->device),
  84                 sizeof(info.device_name));
  85
  86         if (copy_to_user(arg, &info, sizeof(info)))
  87                 return -EFAULT;
  88
  89         return 0;
  90 }
  91
  92 static int hwdep_lock(struct snd_dice *dice)
  93 {
  94         int err;
  95
  96         spin_lock_irq(&dice->lock);
  97
  98         if (dice->dev_lock_count == 0) {
  99                 dice->dev_lock_count = -1;
 100                 err = 0;
 101         } else {
 102                 err = -EBUSY;
 103         }
 104
 105         spin_unlock_irq(&dice->lock);
 106
 107         return err;
 108 }
 109
 110 static int hwdep_unlock(struct snd_dice *dice)
 111 {
 112         int err;
 113
 114         spin_lock_irq(&dice->lock);
 115
 116         if (dice->dev_lock_count == -1) {
 117                 dice->dev_lock_count = 0;
 118                 err = 0;
 119         } else {
 120                 err = -EBADFD;
 121         }
 122
 123         spin_unlock_irq(&dice->lock);
 124
 125         return err;
 126 }
 127
 128 static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
 129 {
 130         struct snd_dice *dice = hwdep->private_data;
 131
 132         spin_lock_irq(&dice->lock);
 133         if (dice->dev_lock_count == -1)
 134                 dice->dev_lock_count = 0;
 135         spin_unlock_irq(&dice->lock);
 136
 137         return 0;
 138 }
 139
 140 static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
 141                        unsigned int cmd, unsigned long arg)
 142 {
 143         struct snd_dice *dice = hwdep->private_data;
 144
 145         switch (cmd) {
 146         case SNDRV_FIREWIRE_IOCTL_GET_INFO:
 147                 return hwdep_get_info(dice, (void __user *)arg);
 148         case SNDRV_FIREWIRE_IOCTL_LOCK:
 149                 return hwdep_lock(dice);
 150         case SNDRV_FIREWIRE_IOCTL_UNLOCK:
 151                 return hwdep_unlock(dice);
 152         default:
 153                 return -ENOIOCTLCMD;
 154         }
 155 }
 156
 157 #ifdef CONFIG_COMPAT
 158 static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
 159                               unsigned int cmd, unsigned long arg)
 160 {
 161         return hwdep_ioctl(hwdep, file, cmd,
 162                            (unsigned long)compat_ptr(arg));
 163 }
 164 #else
 165 #define hwdep_compat_ioctl NULL
 166 #endif
 167
 168 int snd_dice_create_hwdep(struct snd_dice *dice)
 169 {
 170         static const struct snd_hwdep_ops ops = {
 171                 .read         = hwdep_read,
 172                 .release      = hwdep_release,
 173                 .poll         = hwdep_poll,
 174                 .ioctl        = hwdep_ioctl,
 175                 .ioctl_compat = hwdep_compat_ioctl,
 176         };
 177         struct snd_hwdep *hwdep;
 178         int err;
 179
 180         err = snd_hwdep_new(dice->card, "DICE", 0, &hwdep);
 181         if (err < 0)
 182                 return err;
 183         strcpy(hwdep->name, "DICE");
 184         hwdep->iface = SNDRV_HWDEP_IFACE_FW_DICE;
 185         hwdep->ops = ops;
 186         hwdep->private_data = dice;
 187         hwdep->exclusive = true;
 188
 189         return 0;
 190 }