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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * bebob_hwdep.c - a part of driver for BeBoB based devices4 *5 * Copyright (c) 2013-2014 Takashi Sakamoto6 */7 8/*9 * This codes give three functionality.10 *11 * 1.get firewire node infomation12 * 2.get notification about starting/stopping stream13 * 3.lock/unlock stream14 */15 16#include "bebob.h"17 18static long19hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,20 loff_t *offset)21{22 struct snd_bebob *bebob = hwdep->private_data;23 DEFINE_WAIT(wait);24 union snd_firewire_event event;25 26 spin_lock_irq(&bebob->lock);27 28 while (!bebob->dev_lock_changed) {29 prepare_to_wait(&bebob->hwdep_wait, &wait, TASK_INTERRUPTIBLE);30 spin_unlock_irq(&bebob->lock);31 schedule();32 finish_wait(&bebob->hwdep_wait, &wait);33 if (signal_pending(current))34 return -ERESTARTSYS;35 spin_lock_irq(&bebob->lock);36 }37 38 memset(&event, 0, sizeof(event));39 count = min_t(long, count, sizeof(event.lock_status));40 event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;41 event.lock_status.status = (bebob->dev_lock_count > 0);42 bebob->dev_lock_changed = false;43 44 spin_unlock_irq(&bebob->lock);45 46 if (copy_to_user(buf, &event, count))47 return -EFAULT;48 49 return count;50}51 52static __poll_t53hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)54{55 struct snd_bebob *bebob = hwdep->private_data;56 __poll_t events;57 58 poll_wait(file, &bebob->hwdep_wait, wait);59 60 spin_lock_irq(&bebob->lock);61 if (bebob->dev_lock_changed)62 events = EPOLLIN | EPOLLRDNORM;63 else64 events = 0;65 spin_unlock_irq(&bebob->lock);66 67 return events;68}69 70static int71hwdep_get_info(struct snd_bebob *bebob, void __user *arg)72{73 struct fw_device *dev = fw_parent_device(bebob->unit);74 struct snd_firewire_get_info info;75 76 memset(&info, 0, sizeof(info));77 info.type = SNDRV_FIREWIRE_TYPE_BEBOB;78 info.card = dev->card->index;79 *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);80 *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);81 strscpy(info.device_name, dev_name(&dev->device),82 sizeof(info.device_name));83 84 if (copy_to_user(arg, &info, sizeof(info)))85 return -EFAULT;86 87 return 0;88}89 90static int91hwdep_lock(struct snd_bebob *bebob)92{93 int err;94 95 spin_lock_irq(&bebob->lock);96 97 if (bebob->dev_lock_count == 0) {98 bebob->dev_lock_count = -1;99 err = 0;100 } else {101 err = -EBUSY;102 }103 104 spin_unlock_irq(&bebob->lock);105 106 return err;107}108 109static int110hwdep_unlock(struct snd_bebob *bebob)111{112 int err;113 114 spin_lock_irq(&bebob->lock);115 116 if (bebob->dev_lock_count == -1) {117 bebob->dev_lock_count = 0;118 err = 0;119 } else {120 err = -EBADFD;121 }122 123 spin_unlock_irq(&bebob->lock);124 125 return err;126}127 128static int129hwdep_release(struct snd_hwdep *hwdep, struct file *file)130{131 struct snd_bebob *bebob = hwdep->private_data;132 133 spin_lock_irq(&bebob->lock);134 if (bebob->dev_lock_count == -1)135 bebob->dev_lock_count = 0;136 spin_unlock_irq(&bebob->lock);137 138 return 0;139}140 141static int142hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,143 unsigned int cmd, unsigned long arg)144{145 struct snd_bebob *bebob = hwdep->private_data;146 147 switch (cmd) {148 case SNDRV_FIREWIRE_IOCTL_GET_INFO:149 return hwdep_get_info(bebob, (void __user *)arg);150 case SNDRV_FIREWIRE_IOCTL_LOCK:151 return hwdep_lock(bebob);152 case SNDRV_FIREWIRE_IOCTL_UNLOCK:153 return hwdep_unlock(bebob);154 default:155 return -ENOIOCTLCMD;156 }157}158 159#ifdef CONFIG_COMPAT160static int161hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,162 unsigned int cmd, unsigned long arg)163{164 return hwdep_ioctl(hwdep, file, cmd,165 (unsigned long)compat_ptr(arg));166}167#else168#define hwdep_compat_ioctl NULL169#endif170 171int snd_bebob_create_hwdep_device(struct snd_bebob *bebob)172{173 static const struct snd_hwdep_ops ops = {174 .read = hwdep_read,175 .release = hwdep_release,176 .poll = hwdep_poll,177 .ioctl = hwdep_ioctl,178 .ioctl_compat = hwdep_compat_ioctl,179 };180 struct snd_hwdep *hwdep;181 int err;182 183 err = snd_hwdep_new(bebob->card, "BeBoB", 0, &hwdep);184 if (err < 0)185 goto end;186 strcpy(hwdep->name, "BeBoB");187 hwdep->iface = SNDRV_HWDEP_IFACE_FW_BEBOB;188 hwdep->ops = ops;189 hwdep->private_data = bebob;190 hwdep->exclusive = true;191end:192 return err;193}194 195