1 files changed, 330 insertions, 0 deletions
diff --git a/sound/firewire/fireworks/fireworks_hwdep.c b/sound/firewire/fireworks/fireworks_hwdep.c
new file mode 100644
index 000000000..c739173c6
--- /dev/null
+++ b/sound/firewire/fireworks/fireworks_hwdep.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fireworks_hwdep.c - a part of driver for Fireworks based devices
+ *
+ * Copyright (c) 2013-2014 Takashi Sakamoto
+ */
+
+/*
+ * This codes have five functionalities.
+ *
+ * 1.get information about firewire node
+ * 2.get notification about starting/stopping stream
+ * 3.lock/unlock streaming
+ * 4.transmit command of EFW transaction
+ * 5.receive response of EFW transaction
+ *
+ */
+
+#include "fireworks.h"
+
+static long
+hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained,
+		    loff_t *offset)
+{
+	unsigned int length, till_end, type;
+	struct snd_efw_transaction *t;
+	u8 *pull_ptr;
+	long count = 0;
+
+	if (remained < sizeof(type) + sizeof(struct snd_efw_transaction))
+		return -ENOSPC;
+
+	/* data type is SNDRV_FIREWIRE_EVENT_EFW_RESPONSE */
+	type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE;
+	if (copy_to_user(buf, &type, sizeof(type)))
+		return -EFAULT;
+	count += sizeof(type);
+	remained -= sizeof(type);
+	buf += sizeof(type);
+
+	/* write into buffer as many responses as possible */
+	spin_lock_irq(&efw->lock);
+
+	/*
+	 * When another task reaches here during this task's access to user
+	 * space, it picks up current position in buffer and can read the same
+	 * series of responses.
+	 */
+	pull_ptr = efw->pull_ptr;
+
+	while (efw->push_ptr != pull_ptr) {
+		t = (struct snd_efw_transaction *)(pull_ptr);
+		length = be32_to_cpu(t->length) * sizeof(__be32);
+
+		/* confirm enough space for this response */
+		if (remained < length)
+			break;
+
+		/* copy from ring buffer to user buffer */
+		while (length > 0) {
+			till_end = snd_efw_resp_buf_size -
+				(unsigned int)(pull_ptr - efw->resp_buf);
+			till_end = min_t(unsigned int, length, till_end);
+
+			spin_unlock_irq(&efw->lock);
+
+			if (copy_to_user(buf, pull_ptr, till_end))
+				return -EFAULT;
+
+			spin_lock_irq(&efw->lock);
+
+			pull_ptr += till_end;
+			if (pull_ptr >= efw->resp_buf + snd_efw_resp_buf_size)
+				pull_ptr -= snd_efw_resp_buf_size;
+
+			length -= till_end;
+			buf += till_end;
+			count += till_end;
+			remained -= till_end;
+		}
+	}
+
+	/*
+	 * All of tasks can read from the buffer nearly simultaneously, but the
+	 * last position for each task is different depending on the length of
+	 * given buffer. Here, for simplicity, a position of buffer is set by
+	 * the latest task. It's better for a listening application to allow one
+	 * thread to read from the buffer. Unless, each task can read different
+	 * sequence of responses depending on variation of buffer length.
+	 */
+	efw->pull_ptr = pull_ptr;
+
+	spin_unlock_irq(&efw->lock);
+
+	return count;
+}
+
+static long
+hwdep_read_locked(struct snd_efw *efw, char __user *buf, long count,
+		  loff_t *offset)
+{
+	union snd_firewire_event event = {
+		.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
+	};
+
+	spin_lock_irq(&efw->lock);
+
+	event.lock_status.status = (efw->dev_lock_count > 0);
+	efw->dev_lock_changed = false;
+
+	spin_unlock_irq(&efw->lock);
+
+	count = min_t(long, count, sizeof(event.lock_status));
+
+	if (copy_to_user(buf, &event, count))
+		return -EFAULT;
+
+	return count;
+}
+
+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);
+	bool dev_lock_changed;
+	bool queued;
+
+	spin_lock_irq(&efw->lock);
+
+	dev_lock_changed = efw->dev_lock_changed;
+	queued = efw->push_ptr != efw->pull_ptr;
+
+	while (!dev_lock_changed && !queued) {
+		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);
+		dev_lock_changed = efw->dev_lock_changed;
+		queued = efw->push_ptr != efw->pull_ptr;
+	}
+
+	spin_unlock_irq(&efw->lock);
+
+	if (dev_lock_changed)
+		count = hwdep_read_locked(efw, buf, count, offset);
+	else if (queued)
+		count = hwdep_read_resp_buf(efw, buf, count, offset);
+
+	return count;
+}
+
+static long
+hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
+	    loff_t *offset)
+{
+	struct snd_efw *efw = hwdep->private_data;
+	u32 seqnum;
+	u8 *buf;
+
+	if (count < sizeof(struct snd_efw_transaction) ||
+	    SND_EFW_RESPONSE_MAXIMUM_BYTES < count)
+		return -EINVAL;
+
+	buf = memdup_user(data, count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	/* check seqnum is not for kernel-land */
+	seqnum = be32_to_cpu(((struct snd_efw_transaction *)buf)->seqnum);
+	if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX) {
+		count = -EINVAL;
+		goto end;
+	}
+
+	if (snd_efw_transaction_cmd(efw->unit, buf, count) < 0)
+		count = -EIO;
+end:
+	kfree(buf);
+	return count;
+}
+
+static __poll_t
+hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
+{
+	struct snd_efw *efw = hwdep->private_data;
+	__poll_t events;
+
+	poll_wait(file, &efw->hwdep_wait, wait);
+
+	spin_lock_irq(&efw->lock);
+	if (efw->dev_lock_changed || efw->pull_ptr != efw->push_ptr)
+		events = EPOLLIN | EPOLLRDNORM;
+	else
+		events = 0;
+	spin_unlock_irq(&efw->lock);
+
+	return events | EPOLLOUT;
+}
+
+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
+
+int snd_efw_create_hwdep_device(struct snd_efw *efw)
+{
+	static const struct snd_hwdep_ops ops = {
+		.read		= hwdep_read,
+		.write		= hwdep_write,
+		.release	= hwdep_release,
+		.poll		= hwdep_poll,
+		.ioctl		= hwdep_ioctl,
+		.ioctl_compat	= hwdep_compat_ioctl,
+	};
+	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 = ops;
+	hwdep->private_data = efw;
+	hwdep->exclusive = true;
+end:
+	return err;
+}
+