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;
+}