3 files changed, 160 insertions, 15 deletions

diff --git a/sound/firewire/tascam/amdtp-tascam.c b/sound/firewire/tascam/amdtp-tascam.c
index ab482423c165..a52d1f76c610 100644
--- a/sound/firewire/tascam/amdtp-tascam.c
+++ b/sound/firewire/tascam/amdtp-tascam.c
@@ -117,6 +117,55 @@ int amdtp_tscm_add_pcm_hw_constraints(struct amdtp_stream *s,
 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
 }
 
+static void read_status_messages(struct amdtp_stream *s,
+				 __be32 *buffer, unsigned int data_blocks)
+{
+	struct snd_tscm *tscm = container_of(s, struct snd_tscm, tx_stream);
+	bool used = READ_ONCE(tscm->hwdep->used);
+	int i;
+
+	for (i = 0; i < data_blocks; i++) {
+		unsigned int index;
+		__be32 before;
+		__be32 after;
+
+		index = be32_to_cpu(buffer[0]) % SNDRV_FIREWIRE_TASCAM_STATE_COUNT;
+		before = tscm->state[index];
+		after = buffer[s->data_block_quadlets - 1];
+
+		if (used && index > 4 && index < 16) {
+			__be32 mask;
+
+			if (index == 5)
+				mask = cpu_to_be32(~0x0000ffff);
+			else if (index == 6)
+				mask = cpu_to_be32(~0x0000ffff);
+			else if (index == 8)
+				mask = cpu_to_be32(~0x000f0f00);
+			else
+				mask = cpu_to_be32(~0x00000000);
+
+			if ((before ^ after) & mask) {
+				struct snd_firewire_tascam_change *entry =
+						&tscm->queue[tscm->push_pos];
+
+				spin_lock_irq(&tscm->lock);
+				entry->index = index;
+				entry->before = before;
+				entry->after = after;
+				if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT)
+					tscm->push_pos = 0;
+				spin_unlock_irq(&tscm->lock);
+
+				wake_up(&tscm->hwdep_wait);
+			}
+		}
+
+		tscm->state[index] = after;
+		buffer += s->data_block_quadlets;
+	}
+}
+
 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 					   __be32 *buffer,
 					   unsigned int data_blocks,
@@ -128,7 +177,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 	if (data_blocks > 0 && pcm)
 		read_pcm_s32(s, pcm, buffer, data_blocks);
 
-	/* A place holder for control messages. */
+	read_status_messages(s, buffer, data_blocks);
 
 	return data_blocks;
 }
diff --git a/sound/firewire/tascam/tascam-hwdep.c b/sound/firewire/tascam/tascam-hwdep.c
index 4e4c1e9020e8..0414abf5daa8 100644
--- a/sound/firewire/tascam/tascam-hwdep.c
+++ b/sound/firewire/tascam/tascam-hwdep.c
@@ -16,18 +16,93 @@
 
 #include "tascam.h"
 
+static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,
+				   long count, loff_t *offset)
+{
+	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)
+{
+	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);
-	union snd_firewire_event event = {
-		.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
-	};
 
 	spin_lock_irq(&tscm->lock);
 
-	while (!tscm->dev_lock_changed) {
+	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();
@@ -37,15 +112,15 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
 		spin_lock_irq(&tscm->lock);
 	}
 
-	event.lock_status.status = (tscm->dev_lock_count > 0);
-	tscm->dev_lock_changed = false;
-
-	spin_unlock_irq(&tscm->lock);
-
-	count = min_t(long, count, sizeof(event.lock_status));
-
-	if (copy_to_user(buf, &event, count))
-		return -EFAULT;
+	// 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;
 }
@@ -59,7 +134,7 @@ static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
 	poll_wait(file, &tscm->hwdep_wait, wait);
 
 	spin_lock_irq(&tscm->lock);
-	if (tscm->dev_lock_changed)
+	if (tscm->dev_lock_changed || tscm->push_pos != tscm->pull_pos)
 		events = EPOLLIN | EPOLLRDNORM;
 	else
 		events = 0;
@@ -123,6 +198,14 @@ static int hwdep_unlock(struct snd_tscm *tscm)
 	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;
@@ -147,6 +230,8 @@ static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
 		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;
 	}
@@ -185,5 +270,7 @@ int snd_tscm_create_hwdep_device(struct snd_tscm *tscm)
 	hwdep->private_data = tscm;
 	hwdep->exclusive = true;
 
+	tscm->hwdep = hwdep;
+
 	return err;
 }
diff --git a/sound/firewire/tascam/tascam.h b/sound/firewire/tascam/tascam.h
index a5bd167eb5d9..6a411ee0dcf1 100644
--- a/sound/firewire/tascam/tascam.h
+++ b/sound/firewire/tascam/tascam.h
@@ -62,6 +62,8 @@ struct snd_fw_async_midi_port {
 	int consume_bytes;
 };
 
+#define SND_TSCM_QUEUE_COUNT	16
+
 struct snd_tscm {
 	struct snd_card *card;
 	struct fw_unit *unit;
@@ -89,6 +91,13 @@ struct snd_tscm {
 
 	/* For MIDI message outgoing transactions. */
 	struct snd_fw_async_midi_port out_ports[TSCM_MIDI_OUT_PORT_MAX];
+
+	// A cache of status information in tx isoc packets.
+	__be32 state[SNDRV_FIREWIRE_TASCAM_STATE_COUNT];
+	struct snd_hwdep *hwdep;
+	struct snd_firewire_tascam_change queue[SND_TSCM_QUEUE_COUNT];
+	unsigned int pull_pos;
+	unsigned int push_pos;
 };
 
 #define TSCM_ADDR_BASE			0xffff00000000ull