linux/sound/firewire/motu/motu-hwdep.c
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   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
  20static 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
  62static __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
  80static 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
  99static 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
 117static 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
 135static 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
 147static 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
 165static 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
 175int 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}
 199