ALSA: oxfw: Add hwdep interface
This interface is designed for mixer/control application. By using this
interface, an 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>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/firewire/oxfw/oxfw-hwdep.c b/sound/firewire/oxfw/oxfw-hwdep.c
new file mode 100644
index 0000000..ff2687a
--- /dev/null
+++ b/sound/firewire/oxfw/oxfw-hwdep.c
@@ -0,0 +1,190 @@
+/*
+ * oxfw_hwdep.c - a part of driver for OXFW970/971 based devices
+ *
+ * Copyright (c) 2014 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+/*
+ * This codes give three functionality.
+ *
+ * 1.get firewire node information
+ * 2.get notification about starting/stopping stream
+ * 3.lock/unlock stream
+ */
+
+#include "oxfw.h"
+
+static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
+ loff_t *offset)
+{
+ struct snd_oxfw *oxfw = hwdep->private_data;
+ DEFINE_WAIT(wait);
+ union snd_firewire_event event;
+
+ spin_lock_irq(&oxfw->lock);
+
+ while (!oxfw->dev_lock_changed) {
+ prepare_to_wait(&oxfw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
+ spin_unlock_irq(&oxfw->lock);
+ schedule();
+ finish_wait(&oxfw->hwdep_wait, &wait);
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+ spin_lock_irq(&oxfw->lock);
+ }
+
+ memset(&event, 0, sizeof(event));
+ if (oxfw->dev_lock_changed) {
+ event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
+ event.lock_status.status = (oxfw->dev_lock_count > 0);
+ oxfw->dev_lock_changed = false;
+
+ count = min_t(long, count, sizeof(event.lock_status));
+ }
+
+ spin_unlock_irq(&oxfw->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_oxfw *oxfw = hwdep->private_data;
+ unsigned int events;
+
+ poll_wait(file, &oxfw->hwdep_wait, wait);
+
+ spin_lock_irq(&oxfw->lock);
+ if (oxfw->dev_lock_changed)
+ events = POLLIN | POLLRDNORM;
+ else
+ events = 0;
+ spin_unlock_irq(&oxfw->lock);
+
+ return events;
+}
+
+static int hwdep_get_info(struct snd_oxfw *oxfw, void __user *arg)
+{
+ struct fw_device *dev = fw_parent_device(oxfw->unit);
+ struct snd_firewire_get_info info;
+
+ memset(&info, 0, sizeof(info));
+ info.type = SNDRV_FIREWIRE_TYPE_OXFW;
+ 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_oxfw *oxfw)
+{
+ int err;
+
+ spin_lock_irq(&oxfw->lock);
+
+ if (oxfw->dev_lock_count == 0) {
+ oxfw->dev_lock_count = -1;
+ err = 0;
+ } else {
+ err = -EBUSY;
+ }
+
+ spin_unlock_irq(&oxfw->lock);
+
+ return err;
+}
+
+static int hwdep_unlock(struct snd_oxfw *oxfw)
+{
+ int err;
+
+ spin_lock_irq(&oxfw->lock);
+
+ if (oxfw->dev_lock_count == -1) {
+ oxfw->dev_lock_count = 0;
+ err = 0;
+ } else {
+ err = -EBADFD;
+ }
+
+ spin_unlock_irq(&oxfw->lock);
+
+ return err;
+}
+
+static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
+{
+ struct snd_oxfw *oxfw = hwdep->private_data;
+
+ spin_lock_irq(&oxfw->lock);
+ if (oxfw->dev_lock_count == -1)
+ oxfw->dev_lock_count = 0;
+ spin_unlock_irq(&oxfw->lock);
+
+ return 0;
+}
+
+static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct snd_oxfw *oxfw = hwdep->private_data;
+
+ switch (cmd) {
+ case SNDRV_FIREWIRE_IOCTL_GET_INFO:
+ return hwdep_get_info(oxfw, (void __user *)arg);
+ case SNDRV_FIREWIRE_IOCTL_LOCK:
+ return hwdep_lock(oxfw);
+ case SNDRV_FIREWIRE_IOCTL_UNLOCK:
+ return hwdep_unlock(oxfw);
+ 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_oxfw_create_hwdep(struct snd_oxfw *oxfw)
+{
+ 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,
+ };
+ struct snd_hwdep *hwdep;
+ int err;
+
+ err = snd_hwdep_new(oxfw->card, oxfw->card->driver, 0, &hwdep);
+ if (err < 0)
+ goto end;
+ strcpy(hwdep->name, oxfw->card->driver);
+ hwdep->iface = SNDRV_HWDEP_IFACE_FW_OXFW;
+ hwdep->ops = hwdep_ops;
+ hwdep->private_data = oxfw;
+ hwdep->exclusive = true;
+end:
+ return err;
+}