oxfw-hwdep.c
/*
* 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;
}