blob: 8a741b3b0436f3aa0ebb84e231ec186cdefa198f [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* ff-hwdep.c - a part of driver for RME Fireface series
*
* Copyright (c) 2015-2017 Takashi Sakamoto
*/
/*
* This codes give three functionality.
*
* 1.get firewire node information
* 2.get notification about starting/stopping stream
* 3.lock/unlock stream
*/
#include "ff.h"
static bool has_msg(struct snd_ff *ff)
{
if (ff->spec->protocol->has_msg)
return ff->spec->protocol->has_msg(ff);
else
return 0;
}
static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
loff_t *offset)
{
struct snd_ff *ff = hwdep->private_data;
DEFINE_WAIT(wait);
spin_lock_irq(&ff->lock);
while (!ff->dev_lock_changed && !has_msg(ff)) {
prepare_to_wait(&ff->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
spin_unlock_irq(&ff->lock);
schedule();
finish_wait(&ff->hwdep_wait, &wait);
if (signal_pending(current))
return -ERESTARTSYS;
spin_lock_irq(&ff->lock);
}
if (ff->dev_lock_changed && count >= sizeof(struct snd_firewire_event_lock_status)) {
struct snd_firewire_event_lock_status ev = {
.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
.status = (ff->dev_lock_count > 0),
};
ff->dev_lock_changed = false;
spin_unlock_irq(&ff->lock);
if (copy_to_user(buf, &ev, sizeof(ev)))
return -EFAULT;
count = sizeof(ev);
} else if (has_msg(ff)) {
// NOTE: Acquired spin lock should be released before accessing to user space in the
// callback since the access can cause page fault.
count = ff->spec->protocol->copy_msg_to_user(ff, buf, count);
spin_unlock_irq(&ff->lock);
} else {
spin_unlock_irq(&ff->lock);
count = 0;
}
return count;
}
static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
poll_table *wait)
{
struct snd_ff *ff = hwdep->private_data;
__poll_t events;
poll_wait(file, &ff->hwdep_wait, wait);
spin_lock_irq(&ff->lock);
if (ff->dev_lock_changed || has_msg(ff))
events = EPOLLIN | EPOLLRDNORM;
else
events = 0;
spin_unlock_irq(&ff->lock);
return events;
}
static int hwdep_get_info(struct snd_ff *ff, void __user *arg)
{
struct fw_device *dev = fw_parent_device(ff->unit);
struct snd_firewire_get_info info;
memset(&info, 0, sizeof(info));
info.type = SNDRV_FIREWIRE_TYPE_FIREFACE;
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]);
strscpy(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_ff *ff)
{
int err;
spin_lock_irq(&ff->lock);
if (ff->dev_lock_count == 0) {
ff->dev_lock_count = -1;
err = 0;
} else {
err = -EBUSY;
}
spin_unlock_irq(&ff->lock);
return err;
}
static int hwdep_unlock(struct snd_ff *ff)
{
int err;
spin_lock_irq(&ff->lock);
if (ff->dev_lock_count == -1) {
ff->dev_lock_count = 0;
err = 0;
} else {
err = -EBADFD;
}
spin_unlock_irq(&ff->lock);
return err;
}
static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
{
struct snd_ff *ff = hwdep->private_data;
spin_lock_irq(&ff->lock);
if (ff->dev_lock_count == -1)
ff->dev_lock_count = 0;
spin_unlock_irq(&ff->lock);
return 0;
}
static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct snd_ff *ff = hwdep->private_data;
switch (cmd) {
case SNDRV_FIREWIRE_IOCTL_GET_INFO:
return hwdep_get_info(ff, (void __user *)arg);
case SNDRV_FIREWIRE_IOCTL_LOCK:
return hwdep_lock(ff);
case SNDRV_FIREWIRE_IOCTL_UNLOCK:
return hwdep_unlock(ff);
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_ff_create_hwdep_devices(struct snd_ff *ff)
{
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(ff->card, ff->card->driver, 0, &hwdep);
if (err < 0)
return err;
strcpy(hwdep->name, ff->card->driver);
hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREFACE;
hwdep->ops = hwdep_ops;
hwdep->private_data = ff;
hwdep->exclusive = true;
return 0;
}