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         count = min_t(long, count, sizeof(event.lock_status));
  41         if (bebob->dev_lock_changed) {
  42                 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
  43                 event.lock_status.status = (bebob->dev_lock_count > 0);
  44                 bebob->dev_lock_changed = false;
  45         }
  46
  47         spin_unlock_irq(&bebob->lock);
  48
  49         if (copy_to_user(buf, &event, count))
  50                 return -EFAULT;
  51
  52         return count;
  53 }
  54
  55 static unsigned int
  56 hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
  57 {
  58         struct snd_bebob *bebob = hwdep->private_data;
  59         unsigned int events;
  60
  61         poll_wait(file, &bebob->hwdep_wait, wait);
  62
  63         spin_lock_irq(&bebob->lock);
  64         if (bebob->dev_lock_changed)
  65                 events = POLLIN | POLLRDNORM;
  66         else
  67                 events = 0;
  68         spin_unlock_irq(&bebob->lock);
  69
  70         return events;
  71 }
  72
  73 static int
  74 hwdep_get_info(struct snd_bebob *bebob, void __user *arg)
  75 {
  76         struct fw_device *dev = fw_parent_device(bebob->unit);
  77         struct snd_firewire_get_info info;
  78
  79         memset(&info, 0, sizeof(info));
  80         info.type = SNDRV_FIREWIRE_TYPE_BEBOB;
  81         info.card = dev->card->index;
  82         *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
  83         *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
  84         strlcpy(info.device_name, dev_name(&dev->device),
  85                 sizeof(info.device_name));
  86
  87         if (copy_to_user(arg, &info, sizeof(info)))
  88                 return -EFAULT;
  89
  90         return 0;
  91 }
  92
  93 static int
  94 hwdep_lock(struct snd_bebob *bebob)
  95 {
  96         int err;
  97
  98         spin_lock_irq(&bebob->lock);
  99
 100         if (bebob->dev_lock_count == 0) {
 101                 bebob->dev_lock_count = -1;
 102                 err = 0;
 103         } else {
 104                 err = -EBUSY;
 105         }
 106
 107         spin_unlock_irq(&bebob->lock);
 108
 109         return err;
 110 }
 111
 112 static int
 113 hwdep_unlock(struct snd_bebob *bebob)
 114 {
 115         int err;
 116
 117         spin_lock_irq(&bebob->lock);
 118
 119         if (bebob->dev_lock_count == -1) {
 120                 bebob->dev_lock_count = 0;
 121                 err = 0;
 122         } else {
 123                 err = -EBADFD;
 124         }
 125
 126         spin_unlock_irq(&bebob->lock);
 127
 128         return err;
 129 }
 130
 131 static int
 132 hwdep_release(struct snd_hwdep *hwdep, struct file *file)
 133 {
 134         struct snd_bebob *bebob = hwdep->private_data;
 135
 136         spin_lock_irq(&bebob->lock);
 137         if (bebob->dev_lock_count == -1)
 138                 bebob->dev_lock_count = 0;
 139         spin_unlock_irq(&bebob->lock);
 140
 141         return 0;
 142 }
 143
 144 static int
 145 hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
 146             unsigned int cmd, unsigned long arg)
 147 {
 148         struct snd_bebob *bebob = hwdep->private_data;
 149
 150         switch (cmd) {
 151         case SNDRV_FIREWIRE_IOCTL_GET_INFO:
 152                 return hwdep_get_info(bebob, (void __user *)arg);
 153         case SNDRV_FIREWIRE_IOCTL_LOCK:
 154                 return hwdep_lock(bebob);
 155         case SNDRV_FIREWIRE_IOCTL_UNLOCK:
 156                 return hwdep_unlock(bebob);
 157         default:
 158                 return -ENOIOCTLCMD;
 159         }
 160 }
 161
 162 #ifdef CONFIG_COMPAT
 163 static int
 164 hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
 165                    unsigned int cmd, unsigned long arg)
 166 {
 167         return hwdep_ioctl(hwdep, file, cmd,
 168                            (unsigned long)compat_ptr(arg));
 169 }
 170 #else
 171 #define hwdep_compat_ioctl NULL
 172 #endif
 173
 174 static const struct snd_hwdep_ops hwdep_ops = {
 175         .read           = hwdep_read,
 176         .release        = hwdep_release,
 177         .poll           = hwdep_poll,
 178         .ioctl          = hwdep_ioctl,
 179         .ioctl_compat   = hwdep_compat_ioctl,
 180 };
 181
 182 int snd_bebob_create_hwdep_device(struct snd_bebob *bebob)
 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 = hwdep_ops;
 193         hwdep->private_data = bebob;
 194         hwdep->exclusive = true;
 195 end:
 196         return err;
 197 }
 198