Eine aufbereitete Darstellung der Quelle

 
     
 
 
Anforderungen  |   Konzepte  |   Entwurf  |   Entwicklung  |   Qualitätssicherung  |   Lebenszyklus  |   Steuerung
 
 
 
 
Benutzer

products/Sources/formale Sprachen/C/LibreOffice/icon-themes/breeze/cmd/   (Linux Kernel Version 6.17.9©)  Datei vom 5.10.2025 mit Größe 196 B image not shown  

Bilddatei

ff-hwdep.c


products/Sources/formale Sprachen/C/Linux/sound/firewire/fireface/ff-hwdep.c

// 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; strscpy(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; }

                                                                                                                                                                                                                                                                                                                                                                                                     

Neuigkeiten

     Aktuelles
     Motto des Tages

letze Version des Elbe Quellennavigators

Jenseits des Üblichen ....

Besucher

Besucher
Statistik
#Sources=1126864
#Domains=2039723