ALSA: fireworks: Add hwdep interface

This interface is designed for mixer/control application. To use hwdep
interface, the application can get information about firewire node, can
lock/unlock kernel streaming and can get notification at starting/stopping
kernel streaming.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/uapi/sound/asound.h

@@ -94,9 +94,10 @@ enum {
 	SNDRV_HWDEP_IFACE_HDA,		/* HD-audio */
 	SNDRV_HWDEP_IFACE_USB_STREAM,	/* direct access to usb stream */
 	SNDRV_HWDEP_IFACE_FW_DICE,	/* TC DICE FireWire device */
+	SNDRV_HWDEP_IFACE_FW_FIREWORKS,	/* Echo Audio Fireworks based device */
 
 	/* Don't forget to change the following: */
-	SNDRV_HWDEP_IFACE_LAST = SNDRV_HWDEP_IFACE_FW_DICE
+	SNDRV_HWDEP_IFACE_LAST = SNDRV_HWDEP_IFACE_FW_FIREWORKS
 };
 
 struct snd_hwdep_info {

include/uapi/sound/firewire.h

@@ -34,7 +34,8 @@ union snd_firewire_event {
 #define SNDRV_FIREWIRE_IOCTL_UNLOCK    _IO('H', 0xfa)
 
 #define SNDRV_FIREWIRE_TYPE_DICE	1
-/* Fireworks, AV/C, RME, MOTU, ... */
+#define SNDRV_FIREWIRE_TYPE_FIREWORKS	2
+/* AV/C, RME, MOTU, ... */
 
 struct snd_firewire_get_info {
 	unsigned int type; /* SNDRV_FIREWIRE_TYPE_xxx */

sound/firewire/Kconfig

@@ -66,6 +66,7 @@ config SND_FIREWORKS
 	select SND_FIREWIRE_LIB
 	select SND_RAWMIDI
 	select SND_PCM
+	select SND_HWDEP
 	help
 	  Say Y here to include support for FireWire devices based
 	  on Echo Digital Audio Fireworks board:

sound/firewire/fireworks/Makefile

 snd-fireworks-objs := fireworks_transaction.o fireworks_command.o \
 		      fireworks_stream.o fireworks_proc.o fireworks_midi.o \
-		      fireworks_pcm.o fireworks.o
+		      fireworks_pcm.o fireworks_hwdep.o fireworks.o
 obj-m += snd-fireworks.o

sound/firewire/fireworks/fireworks.c

@@ -217,6 +217,7 @@ efw_probe(struct fw_unit *unit,
 	efw->unit = unit;
 	mutex_init(&efw->mutex);
 	spin_lock_init(&efw->lock);
+	init_waitqueue_head(&efw->hwdep_wait);
 
 	err = get_hardware_info(efw);
 	if (err < 0)
@@ -236,6 +237,10 @@ efw_probe(struct fw_unit *unit,
 	if (err < 0)
 		goto error;
 
+	err = snd_efw_create_hwdep_device(efw);
+	if (err < 0)
+		goto error;
+
 	err = snd_efw_stream_init_duplex(efw);
 	if (err < 0)
 		goto error;

sound/firewire/fireworks/fireworks.h

@@ -24,6 +24,8 @@
 #include <sound/info.h>
 #include <sound/rawmidi.h>
 #include <sound/pcm_params.h>
+#include <sound/firewire.h>
+#include <sound/hwdep.h>
 
 #include "../packets-buffer.h"
 #include "../iso-resources.h"
@@ -90,6 +92,11 @@ struct snd_efw {
 	unsigned int phys_in_grp_count;
 	struct snd_efw_phys_grp phys_out_grps[HWINFO_MAX_CAPS_GROUPS];
 	struct snd_efw_phys_grp phys_in_grps[HWINFO_MAX_CAPS_GROUPS];
+
+	/* for uapi */
+	int dev_lock_count;
+	bool dev_lock_changed;
+	wait_queue_head_t hwdep_wait;
 };
 
 struct snd_efw_transaction {
@@ -197,6 +204,9 @@ int snd_efw_stream_start_duplex(struct snd_efw *efw, int sampling_rate);
 void snd_efw_stream_stop_duplex(struct snd_efw *efw);
 void snd_efw_stream_update_duplex(struct snd_efw *efw);
 void snd_efw_stream_destroy_duplex(struct snd_efw *efw);
+void snd_efw_stream_lock_changed(struct snd_efw *efw);
+int snd_efw_stream_lock_try(struct snd_efw *efw);
+void snd_efw_stream_lock_release(struct snd_efw *efw);
 
 void snd_efw_proc_init(struct snd_efw *efw);
 
@@ -205,6 +215,8 @@ int snd_efw_create_midi_devices(struct snd_efw *efw);
 int snd_efw_create_pcm_devices(struct snd_efw *efw);
 int snd_efw_get_multiplier_mode(unsigned int sampling_rate, unsigned int *mode);
 
+int snd_efw_create_hwdep_device(struct snd_efw *efw);
+
 #define SND_EFW_DEV_ENTRY(vendor, model) \
 { \
 	.match_flags	= IEEE1394_MATCH_VENDOR_ID | \

sound/firewire/fireworks/fireworks_hwdep.c

+/*
+ * fireworks_hwdep.c - a part of driver for Fireworks based devices
+ *
+ * Copyright (c) 2013-2014 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+/*
+ * This codes have three functionalities.
+ *
+ * 1.get information about firewire node
+ * 2.get notification about starting/stopping stream
+ * 3.lock/unlock streaming
+ */
+
+#include "fireworks.h"
+
+static long
+hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
+	   loff_t *offset)
+{
+	struct snd_efw *efw = hwdep->private_data;
+	DEFINE_WAIT(wait);
+	union snd_firewire_event event;
+
+	spin_lock_irq(&efw->lock);
+
+	while (!efw->dev_lock_changed) {
+		prepare_to_wait(&efw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
+		spin_unlock_irq(&efw->lock);
+		schedule();
+		finish_wait(&efw->hwdep_wait, &wait);
+		if (signal_pending(current))
+			return -ERESTARTSYS;
+		spin_lock_irq(&efw->lock);
+	}
+
+	memset(&event, 0, sizeof(event));
+	if (efw->dev_lock_changed) {
+		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
+		event.lock_status.status = (efw->dev_lock_count > 0);
+		efw->dev_lock_changed = false;
+
+		count = min_t(long, count, sizeof(event.lock_status));
+	}
+
+	spin_unlock_irq(&efw->lock);
+
+	if (copy_to_user(buf, &event, count))
+		return -EFAULT;
+
+	return count;
+}
+
+static unsigned int
+hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
+{
+	struct snd_efw *efw = hwdep->private_data;
+	unsigned int events;
+
+	poll_wait(file, &efw->hwdep_wait, wait);
+
+	spin_lock_irq(&efw->lock);
+	if (efw->dev_lock_changed)
+		events = POLLIN | POLLRDNORM;
+	else
+		events = 0;
+	spin_unlock_irq(&efw->lock);
+
+	return events;
+}
+
+static int
+hwdep_get_info(struct snd_efw *efw, void __user *arg)
+{
+	struct fw_device *dev = fw_parent_device(efw->unit);
+	struct snd_firewire_get_info info;
+
+	memset(&info, 0, sizeof(info));
+	info.type = SNDRV_FIREWIRE_TYPE_FIREWORKS;
+	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]);
+	strlcpy(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_efw *efw)
+{
+	int err;
+
+	spin_lock_irq(&efw->lock);
+
+	if (efw->dev_lock_count == 0) {
+		efw->dev_lock_count = -1;
+		err = 0;
+	} else {
+		err = -EBUSY;
+	}
+
+	spin_unlock_irq(&efw->lock);
+
+	return err;
+}
+
+static int
+hwdep_unlock(struct snd_efw *efw)
+{
+	int err;
+
+	spin_lock_irq(&efw->lock);
+
+	if (efw->dev_lock_count == -1) {
+		efw->dev_lock_count = 0;
+		err = 0;
+	} else {
+		err = -EBADFD;
+	}
+
+	spin_unlock_irq(&efw->lock);
+
+	return err;
+}
+
+static int
+hwdep_release(struct snd_hwdep *hwdep, struct file *file)
+{
+	struct snd_efw *efw = hwdep->private_data;
+
+	spin_lock_irq(&efw->lock);
+	if (efw->dev_lock_count == -1)
+		efw->dev_lock_count = 0;
+	spin_unlock_irq(&efw->lock);
+
+	return 0;
+}
+
+static int
+hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
+	    unsigned int cmd, unsigned long arg)
+{
+	struct snd_efw *efw = hwdep->private_data;
+
+	switch (cmd) {
+	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
+		return hwdep_get_info(efw, (void __user *)arg);
+	case SNDRV_FIREWIRE_IOCTL_LOCK:
+		return hwdep_lock(efw);
+	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
+		return hwdep_unlock(efw);
+	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
+
+static const struct snd_hwdep_ops hwdep_ops = {
+	.read		= hwdep_read,
+	.release	= hwdep_release,
+	.poll		= hwdep_poll,
+	.ioctl		= hwdep_ioctl,
+	.ioctl_compat	= hwdep_compat_ioctl,
+};
+
+int snd_efw_create_hwdep_device(struct snd_efw *efw)
+{
+	struct snd_hwdep *hwdep;
+	int err;
+
+	err = snd_hwdep_new(efw->card, "Fireworks", 0, &hwdep);
+	if (err < 0)
+		goto end;
+	strcpy(hwdep->name, "Fireworks");
+	hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREWORKS;
+	hwdep->ops = hwdep_ops;
+	hwdep->private_data = efw;
+	hwdep->exclusive = true;
+end:
+	return err;
+}
+

sound/firewire/fireworks/fireworks_midi.c

@@ -11,17 +11,36 @@
 static int midi_capture_open(struct snd_rawmidi_substream *substream)
 {
 	struct snd_efw *efw = substream->rmidi->private_data;
+	int err;
+
+	err = snd_efw_stream_lock_try(efw);
+	if (err < 0)
+		goto end;
 
 	atomic_inc(&efw->capture_substreams);
-	return snd_efw_stream_start_duplex(efw, 0);
+	err = snd_efw_stream_start_duplex(efw, 0);
+	if (err < 0)
+		snd_efw_stream_lock_release(efw);
+
+end:
+	return err;
 }
 
 static int midi_playback_open(struct snd_rawmidi_substream *substream)
 {
 	struct snd_efw *efw = substream->rmidi->private_data;
+	int err;
+
+	err = snd_efw_stream_lock_try(efw);
+	if (err < 0)
+		goto end;
 
 	atomic_inc(&efw->playback_substreams);
-	return snd_efw_stream_start_duplex(efw, 0);
+	err = snd_efw_stream_start_duplex(efw, 0);
+	if (err < 0)
+		snd_efw_stream_lock_release(efw);
+end:
+	return err;
 }
 
 static int midi_capture_close(struct snd_rawmidi_substream *substream)
@@ -31,6 +50,7 @@ static int midi_capture_close(struct snd_rawmidi_substream *substream)
 	atomic_dec(&efw->capture_substreams);
 	snd_efw_stream_stop_duplex(efw);
 
+	snd_efw_stream_lock_release(efw);
 	return 0;
 }
 
@@ -41,6 +61,7 @@ static int midi_playback_close(struct snd_rawmidi_substream *substream)
 	atomic_dec(&efw->playback_substreams);
 	snd_efw_stream_stop_duplex(efw);
 
+	snd_efw_stream_lock_release(efw);
 	return 0;
 }
 

sound/firewire/fireworks/fireworks_pcm.c

@@ -199,13 +199,17 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	unsigned int clock_source;
 	int err;
 
-	err = pcm_init_hw_params(efw, substream);
+	err = snd_efw_stream_lock_try(efw);
 	if (err < 0)
 		goto end;
 
+	err = pcm_init_hw_params(efw, substream);
+	if (err < 0)
+		goto err_locked;
+
 	err = snd_efw_command_get_clock_source(efw, &clock_source);
 	if (err < 0)
-		goto end;
+		goto err_locked;
 
 	/*
 	 * When source of clock is not internal or any PCM streams are running,
@@ -216,7 +220,7 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	    amdtp_stream_pcm_running(&efw->rx_stream)) {
 		err = snd_efw_command_get_sampling_rate(efw, &sampling_rate);
 		if (err < 0)
-			goto end;
+			goto err_locked;
 		substream->runtime->hw.rate_min = sampling_rate;
 		substream->runtime->hw.rate_max = sampling_rate;
 	}
@@ -224,10 +228,15 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	snd_pcm_set_sync(substream);
 end:
 	return err;
+err_locked:
+	snd_efw_stream_lock_release(efw);
+	return err;
 }
 
 static int pcm_close(struct snd_pcm_substream *substream)
 {
+	struct snd_efw *efw = substream->private_data;
+	snd_efw_stream_lock_release(efw);
 	return 0;
 }
 

sound/firewire/fireworks/fireworks_stream.c

@@ -331,3 +331,42 @@ void snd_efw_stream_destroy_duplex(struct snd_efw *efw)
 
 	mutex_unlock(&efw->mutex);
 }
+
+void snd_efw_stream_lock_changed(struct snd_efw *efw)
+{
+	efw->dev_lock_changed = true;
+	wake_up(&efw->hwdep_wait);
+}
+
+int snd_efw_stream_lock_try(struct snd_efw *efw)
+{
+	int err;
+
+	spin_lock_irq(&efw->lock);
+
+	/* user land lock this */
+	if (efw->dev_lock_count < 0) {
+		err = -EBUSY;
+		goto end;
+	}
+
+	/* this is the first time */
+	if (efw->dev_lock_count++ == 0)
+		snd_efw_stream_lock_changed(efw);
+	err = 0;
+end:
+	spin_unlock_irq(&efw->lock);
+	return err;
+}
+
+void snd_efw_stream_lock_release(struct snd_efw *efw)
+{
+	spin_lock_irq(&efw->lock);
+
+	if (WARN_ON(efw->dev_lock_count <= 0))
+		goto end;
+	if (--efw->dev_lock_count == 0)
+		snd_efw_stream_lock_changed(efw);
+end:
+	spin_unlock_irq(&efw->lock);
+}