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-rw-r--r--sound/firewire/tascam/tascam-hwdep.c277
1 files changed, 277 insertions, 0 deletions
diff --git a/sound/firewire/tascam/tascam-hwdep.c b/sound/firewire/tascam/tascam-hwdep.c
new file mode 100644
index 000000000..74eed9505
--- /dev/null
+++ b/sound/firewire/tascam/tascam-hwdep.c
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * tascam-hwdep.c - a part of driver for TASCAM FireWire series
+ *
+ * Copyright (c) 2015 Takashi Sakamoto
+ */
+
+/*
+ * This codes give three functionality.
+ *
+ * 1.get firewire node information
+ * 2.get notification about starting/stopping stream
+ * 3.lock/unlock stream
+ */
+
+#include "tascam.h"
+
+static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,
+ long count, loff_t *offset)
+ __releases(&tscm->lock)
+{
+ struct snd_firewire_event_lock_status event = {
+ .type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
+ };
+
+ event.status = (tscm->dev_lock_count > 0);
+ tscm->dev_lock_changed = false;
+ count = min_t(long, count, sizeof(event));
+
+ spin_unlock_irq(&tscm->lock);
+
+ if (copy_to_user(buf, &event, count))
+ return -EFAULT;
+
+ return count;
+}
+
+static long tscm_hwdep_read_queue(struct snd_tscm *tscm, char __user *buf,
+ long remained, loff_t *offset)
+ __releases(&tscm->lock)
+{
+ char __user *pos = buf;
+ unsigned int type = SNDRV_FIREWIRE_EVENT_TASCAM_CONTROL;
+ struct snd_firewire_tascam_change *entries = tscm->queue;
+ long count;
+
+ // At least, one control event can be copied.
+ if (remained < sizeof(type) + sizeof(*entries)) {
+ spin_unlock_irq(&tscm->lock);
+ return -EINVAL;
+ }
+
+ // Copy the type field later.
+ count = sizeof(type);
+ remained -= sizeof(type);
+ pos += sizeof(type);
+
+ while (true) {
+ unsigned int head_pos;
+ unsigned int tail_pos;
+ unsigned int length;
+
+ if (tscm->pull_pos == tscm->push_pos)
+ break;
+ else if (tscm->pull_pos < tscm->push_pos)
+ tail_pos = tscm->push_pos;
+ else
+ tail_pos = SND_TSCM_QUEUE_COUNT;
+ head_pos = tscm->pull_pos;
+
+ length = (tail_pos - head_pos) * sizeof(*entries);
+ if (remained < length)
+ length = rounddown(remained, sizeof(*entries));
+ if (length == 0)
+ break;
+
+ spin_unlock_irq(&tscm->lock);
+ if (copy_to_user(pos, &entries[head_pos], length))
+ return -EFAULT;
+
+ spin_lock_irq(&tscm->lock);
+
+ tscm->pull_pos = tail_pos % SND_TSCM_QUEUE_COUNT;
+
+ count += length;
+ remained -= length;
+ pos += length;
+ }
+
+ spin_unlock_irq(&tscm->lock);
+
+ if (copy_to_user(buf, &type, sizeof(type)))
+ return -EFAULT;
+
+ return count;
+}
+
+static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
+ loff_t *offset)
+{
+ struct snd_tscm *tscm = hwdep->private_data;
+ DEFINE_WAIT(wait);
+
+ spin_lock_irq(&tscm->lock);
+
+ while (!tscm->dev_lock_changed && tscm->push_pos == tscm->pull_pos) {
+ prepare_to_wait(&tscm->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
+ spin_unlock_irq(&tscm->lock);
+ schedule();
+ finish_wait(&tscm->hwdep_wait, &wait);
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+ spin_lock_irq(&tscm->lock);
+ }
+
+ // NOTE: The acquired lock should be released in callee side.
+ if (tscm->dev_lock_changed) {
+ count = tscm_hwdep_read_locked(tscm, buf, count, offset);
+ } else if (tscm->push_pos != tscm->pull_pos) {
+ count = tscm_hwdep_read_queue(tscm, buf, count, offset);
+ } else {
+ spin_unlock_irq(&tscm->lock);
+ count = 0;
+ }
+
+ return count;
+}
+
+static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
+ poll_table *wait)
+{
+ struct snd_tscm *tscm = hwdep->private_data;
+ __poll_t events;
+
+ poll_wait(file, &tscm->hwdep_wait, wait);
+
+ spin_lock_irq(&tscm->lock);
+ if (tscm->dev_lock_changed || tscm->push_pos != tscm->pull_pos)
+ events = EPOLLIN | EPOLLRDNORM;
+ else
+ events = 0;
+ spin_unlock_irq(&tscm->lock);
+
+ return events;
+}
+
+static int hwdep_get_info(struct snd_tscm *tscm, void __user *arg)
+{
+ struct fw_device *dev = fw_parent_device(tscm->unit);
+ struct snd_firewire_get_info info;
+
+ memset(&info, 0, sizeof(info));
+ info.type = SNDRV_FIREWIRE_TYPE_TASCAM;
+ info.card = dev->card->index;
+ *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
+ *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
+ strscpy(info.device_name, dev_name(&dev->device),
+ sizeof(info.device_name));
+
+ if (copy_to_user(arg, &info, sizeof(info)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int hwdep_lock(struct snd_tscm *tscm)
+{
+ int err;
+
+ spin_lock_irq(&tscm->lock);
+
+ if (tscm->dev_lock_count == 0) {
+ tscm->dev_lock_count = -1;
+ err = 0;
+ } else {
+ err = -EBUSY;
+ }
+
+ spin_unlock_irq(&tscm->lock);
+
+ return err;
+}
+
+static int hwdep_unlock(struct snd_tscm *tscm)
+{
+ int err;
+
+ spin_lock_irq(&tscm->lock);
+
+ if (tscm->dev_lock_count == -1) {
+ tscm->dev_lock_count = 0;
+ err = 0;
+ } else {
+ err = -EBADFD;
+ }
+
+ spin_unlock_irq(&tscm->lock);
+
+ return err;
+}
+
+static int tscm_hwdep_state(struct snd_tscm *tscm, void __user *arg)
+{
+ if (copy_to_user(arg, tscm->state, sizeof(tscm->state)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
+{
+ struct snd_tscm *tscm = hwdep->private_data;
+
+ spin_lock_irq(&tscm->lock);
+ if (tscm->dev_lock_count == -1)
+ tscm->dev_lock_count = 0;
+ spin_unlock_irq(&tscm->lock);
+
+ return 0;
+}
+
+static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct snd_tscm *tscm = hwdep->private_data;
+
+ switch (cmd) {
+ case SNDRV_FIREWIRE_IOCTL_GET_INFO:
+ return hwdep_get_info(tscm, (void __user *)arg);
+ case SNDRV_FIREWIRE_IOCTL_LOCK:
+ return hwdep_lock(tscm);
+ case SNDRV_FIREWIRE_IOCTL_UNLOCK:
+ return hwdep_unlock(tscm);
+ case SNDRV_FIREWIRE_IOCTL_TASCAM_STATE:
+ return tscm_hwdep_state(tscm, (void __user *)arg);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+#ifdef CONFIG_COMPAT
+static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ return hwdep_ioctl(hwdep, file, cmd,
+ (unsigned long)compat_ptr(arg));
+}
+#else
+#define hwdep_compat_ioctl NULL
+#endif
+
+int snd_tscm_create_hwdep_device(struct snd_tscm *tscm)
+{
+ static const struct snd_hwdep_ops ops = {
+ .read = hwdep_read,
+ .release = hwdep_release,
+ .poll = hwdep_poll,
+ .ioctl = hwdep_ioctl,
+ .ioctl_compat = hwdep_compat_ioctl,
+ };
+ struct snd_hwdep *hwdep;
+ int err;
+
+ err = snd_hwdep_new(tscm->card, "Tascam", 0, &hwdep);
+ if (err < 0)
+ return err;
+
+ strcpy(hwdep->name, "Tascam");
+ hwdep->iface = SNDRV_HWDEP_IFACE_FW_TASCAM;
+ hwdep->ops = ops;
+ hwdep->private_data = tscm;
+ hwdep->exclusive = true;
+
+ tscm->hwdep = hwdep;
+
+ return err;
+}