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>

1 files changed, 199 insertions, 0 deletions

diff --git a/sound/firewire/fireworks/fireworks_hwdep.c b/sound/firewire/fireworks/fireworks_hwdep.c
new file mode 100644
index 000000000000..1cf491dc39a3
--- /dev/null
+++ b/sound/firewire/fireworks/fireworks_hwdep.c
@@ -0,0 +1,199 @@
+/*
+ * 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;
+}
+