sound/firewire/bebob/bebob_hwdep.c

   1 /*
   2  * bebob_hwdep.c - a part of driver for BeBoB based devices
   3  *
   4  * Copyright (c) 2013-2014 Takashi Sakamoto
   5  *
   6  * Licensed under the terms of the GNU General Public License, version 2.
   7  */
   8
   9 /*
  10  * This codes give three functionality.
  11  *
  12  * 1.get firewire node infomation
  13  * 2.get notification about starting/stopping stream
  14  * 3.lock/unlock stream
  15  */
  16
  17 #include "bebob.h"
  18
  19 static long
  20 hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
  21            loff_t *offset)
  22 {
  23         struct snd_bebob *bebob = hwdep->private_data;
  24         DEFINE_WAIT(wait);
  25         union snd_firewire_event event;
  26
  27         spin_lock_irq(&bebob->lock);
  28
  29         while (!bebob->dev_lock_changed) {
  30                 prepare_to_wait(&bebob->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
  31                 spin_unlock_irq(&bebob->lock);
  32                 schedule();
  33                 finish_wait(&bebob->hwdep_wait, &wait);
  34                 if (signal_pending(current))
  35                         return -ERESTARTSYS;
  36                 spin_lock_irq(&bebob->lock);
  37         }
  38
  39         memset(&event, 0, sizeof(event));
  40         if (bebob->dev_lock_changed) {
  41                 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
  42                 event.lock_status.status = (bebob->dev_lock_count > 0);
  43                 bebob->dev_lock_changed = false;
  44
  45                 count = min_t(long, count, sizeof(event.lock_status));
  46         }
  47
  48         spin_unlock_irq(&bebob->lock);
  49
  50         if (copy_to_user(buf, &event, count))
  51                 return -EFAULT;
  52
  53         return count;
  54 }
  55
  56 static __poll_t
  57 hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
  58 {
  59         struct snd_bebob *bebob = hwdep->private_data;
  60         __poll_t events;
  61
  62         poll_wait(file, &bebob->hwdep_wait, wait);
  63
  64         spin_lock_irq(&bebob->lock);
  65         if (bebob->dev_lock_changed)
  66                 events = EPOLLIN | EPOLLRDNORM;
  67         else
  68                 events = 0;
  69         spin_unlock_irq(&bebob->lock);
  70
  71         return events;
  72 }
  73
  74 static int
  75 hwdep_get_info(struct snd_bebob *bebob, void __user *arg)
  76 {
  77         struct fw_device *dev = fw_parent_device(bebob->unit);
  78         struct snd_firewire_get_info info;
  79
  80         memset(&info, 0, sizeof(info));
  81         info.type = SNDRV_FIREWIRE_TYPE_BEBOB;
  82         info.card = dev->card->index;
  83         *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
  84         *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
  85         strlcpy(info.device_name, dev_name(&dev->device),
  86                 sizeof(info.device_name));
  87
  88         if (copy_to_user(arg, &info, sizeof(info)))
  89                 return -EFAULT;
  90
  91         return 0;
  92 }
  93
  94 static int
  95 hwdep_lock(struct snd_bebob *bebob)
  96 {
  97         int err;
  98
  99         spin_lock_irq(&bebob->lock);
 100
 101         if (bebob->dev_lock_count == 0) {
 102                 bebob->dev_lock_count = -1;
 103                 err = 0;
 104         } else {
 105                 err = -EBUSY;
 106         }
 107
 108         spin_unlock_irq(&bebob->lock);
 109
 110         return err;
 111 }
 112
 113 static int
 114 hwdep_unlock(struct snd_bebob *bebob)
 115 {
 116         int err;
 117
 118         spin_lock_irq(&bebob->lock);
 119
 120         if (bebob->dev_lock_count == -1) {
 121                 bebob->dev_lock_count = 0;
 122                 err = 0;
 123         } else {
 124                 err = -EBADFD;
 125         }
 126
 127         spin_unlock_irq(&bebob->lock);
 128
 129         return err;
 130 }
 131
 132 static int
 133 hwdep_release(struct snd_hwdep *hwdep, struct file *file)
 134 {
 135         struct snd_bebob *bebob = hwdep->private_data;
 136
 137         spin_lock_irq(&bebob->lock);
 138         if (bebob->dev_lock_count == -1)
 139                 bebob->dev_lock_count = 0;
 140         spin_unlock_irq(&bebob->lock);
 141
 142         return 0;
 143 }
 144
 145 static int
 146 hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
 147             unsigned int cmd, unsigned long arg)
 148 {
 149         struct snd_bebob *bebob = hwdep->private_data;
 150
 151         switch (cmd) {
 152         case SNDRV_FIREWIRE_IOCTL_GET_INFO:
 153                 return hwdep_get_info(bebob, (void __user *)arg);
 154         case SNDRV_FIREWIRE_IOCTL_LOCK:
 155                 return hwdep_lock(bebob);
 156         case SNDRV_FIREWIRE_IOCTL_UNLOCK:
 157                 return hwdep_unlock(bebob);
 158         default:
 159                 return -ENOIOCTLCMD;
 160         }
 161 }
 162
 163 #ifdef CONFIG_COMPAT
 164 static int
 165 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_bebob_create_hwdep_device(struct snd_bebob *bebob)
 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(bebob->card, "BeBoB", 0, &hwdep);
 188         if (err < 0)
 189                 goto end;
 190         strcpy(hwdep->name, "BeBoB");
 191         hwdep->iface = SNDRV_HWDEP_IFACE_FW_BEBOB;
 192         hwdep->ops = ops;
 193         hwdep->private_data = bebob;
 194         hwdep->exclusive = true;
 195 end:
 196         return err;
 197 }
 198