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![Takashi Sakamoto](/assets/img/avatar_default.png)
To reverse a pointer for the ring buffer, subtraction by buffer size is better than assignment to the beginning of the buffer. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
298 lines
6.4 KiB
C
298 lines
6.4 KiB
C
/*
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* fireworks_hwdep.c - a part of driver for Fireworks based devices
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*
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* Copyright (c) 2013-2014 Takashi Sakamoto
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*
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* Licensed under the terms of the GNU General Public License, version 2.
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*/
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/*
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* This codes have five functionalities.
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*
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* 1.get information about firewire node
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* 2.get notification about starting/stopping stream
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* 3.lock/unlock streaming
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* 4.transmit command of EFW transaction
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* 5.receive response of EFW transaction
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*
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*/
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#include "fireworks.h"
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static long
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hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained,
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loff_t *offset)
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{
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unsigned int length, till_end, type;
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struct snd_efw_transaction *t;
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long count = 0;
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if (remained < sizeof(type) + sizeof(struct snd_efw_transaction))
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return -ENOSPC;
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/* data type is SNDRV_FIREWIRE_EVENT_EFW_RESPONSE */
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type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE;
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if (copy_to_user(buf, &type, sizeof(type)))
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return -EFAULT;
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remained -= sizeof(type);
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buf += sizeof(type);
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/* write into buffer as many responses as possible */
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while (efw->resp_queues > 0) {
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t = (struct snd_efw_transaction *)(efw->pull_ptr);
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length = be32_to_cpu(t->length) * sizeof(__be32);
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/* confirm enough space for this response */
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if (remained < length)
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break;
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/* copy from ring buffer to user buffer */
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while (length > 0) {
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till_end = snd_efw_resp_buf_size -
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(unsigned int)(efw->pull_ptr - efw->resp_buf);
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till_end = min_t(unsigned int, length, till_end);
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if (copy_to_user(buf, efw->pull_ptr, till_end))
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return -EFAULT;
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efw->pull_ptr += till_end;
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if (efw->pull_ptr >= efw->resp_buf +
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snd_efw_resp_buf_size)
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efw->pull_ptr -= snd_efw_resp_buf_size;
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length -= till_end;
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buf += till_end;
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count += till_end;
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remained -= till_end;
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}
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efw->resp_queues--;
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}
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return count;
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}
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static long
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hwdep_read_locked(struct snd_efw *efw, char __user *buf, long count,
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loff_t *offset)
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{
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union snd_firewire_event event;
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memset(&event, 0, sizeof(event));
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event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
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event.lock_status.status = (efw->dev_lock_count > 0);
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efw->dev_lock_changed = false;
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count = min_t(long, count, sizeof(event.lock_status));
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if (copy_to_user(buf, &event, count))
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return -EFAULT;
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return count;
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}
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static long
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hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
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loff_t *offset)
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{
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struct snd_efw *efw = hwdep->private_data;
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DEFINE_WAIT(wait);
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spin_lock_irq(&efw->lock);
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while ((!efw->dev_lock_changed) && (efw->resp_queues == 0)) {
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prepare_to_wait(&efw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
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spin_unlock_irq(&efw->lock);
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schedule();
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finish_wait(&efw->hwdep_wait, &wait);
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if (signal_pending(current))
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return -ERESTARTSYS;
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spin_lock_irq(&efw->lock);
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}
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if (efw->dev_lock_changed)
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count = hwdep_read_locked(efw, buf, count, offset);
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else if (efw->resp_queues > 0)
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count = hwdep_read_resp_buf(efw, buf, count, offset);
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spin_unlock_irq(&efw->lock);
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return count;
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}
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static long
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hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
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loff_t *offset)
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{
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struct snd_efw *efw = hwdep->private_data;
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u32 seqnum;
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u8 *buf;
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if (count < sizeof(struct snd_efw_transaction) ||
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SND_EFW_RESPONSE_MAXIMUM_BYTES < count)
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return -EINVAL;
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buf = memdup_user(data, count);
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if (IS_ERR(buf))
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return PTR_ERR(buf);
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/* check seqnum is not for kernel-land */
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seqnum = be32_to_cpu(((struct snd_efw_transaction *)buf)->seqnum);
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if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX) {
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count = -EINVAL;
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goto end;
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}
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if (snd_efw_transaction_cmd(efw->unit, buf, count) < 0)
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count = -EIO;
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end:
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kfree(buf);
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return count;
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}
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static unsigned int
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hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
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{
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struct snd_efw *efw = hwdep->private_data;
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unsigned int events;
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poll_wait(file, &efw->hwdep_wait, wait);
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spin_lock_irq(&efw->lock);
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if (efw->dev_lock_changed || (efw->resp_queues > 0))
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events = POLLIN | POLLRDNORM;
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else
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events = 0;
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spin_unlock_irq(&efw->lock);
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return events | POLLOUT;
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}
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static int
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hwdep_get_info(struct snd_efw *efw, void __user *arg)
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{
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struct fw_device *dev = fw_parent_device(efw->unit);
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struct snd_firewire_get_info info;
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memset(&info, 0, sizeof(info));
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info.type = SNDRV_FIREWIRE_TYPE_FIREWORKS;
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info.card = dev->card->index;
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*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
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*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
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strlcpy(info.device_name, dev_name(&dev->device),
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sizeof(info.device_name));
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if (copy_to_user(arg, &info, sizeof(info)))
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return -EFAULT;
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return 0;
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}
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static int
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hwdep_lock(struct snd_efw *efw)
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{
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int err;
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spin_lock_irq(&efw->lock);
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if (efw->dev_lock_count == 0) {
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efw->dev_lock_count = -1;
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err = 0;
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} else {
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err = -EBUSY;
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}
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spin_unlock_irq(&efw->lock);
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return err;
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}
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static int
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hwdep_unlock(struct snd_efw *efw)
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{
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int err;
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spin_lock_irq(&efw->lock);
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if (efw->dev_lock_count == -1) {
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efw->dev_lock_count = 0;
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err = 0;
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} else {
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err = -EBADFD;
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}
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spin_unlock_irq(&efw->lock);
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return err;
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}
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static int
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hwdep_release(struct snd_hwdep *hwdep, struct file *file)
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{
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struct snd_efw *efw = hwdep->private_data;
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spin_lock_irq(&efw->lock);
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if (efw->dev_lock_count == -1)
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efw->dev_lock_count = 0;
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spin_unlock_irq(&efw->lock);
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return 0;
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}
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static int
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hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct snd_efw *efw = hwdep->private_data;
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switch (cmd) {
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case SNDRV_FIREWIRE_IOCTL_GET_INFO:
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return hwdep_get_info(efw, (void __user *)arg);
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case SNDRV_FIREWIRE_IOCTL_LOCK:
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return hwdep_lock(efw);
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case SNDRV_FIREWIRE_IOCTL_UNLOCK:
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return hwdep_unlock(efw);
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default:
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return -ENOIOCTLCMD;
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}
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}
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#ifdef CONFIG_COMPAT
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static int
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hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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return hwdep_ioctl(hwdep, file, cmd,
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(unsigned long)compat_ptr(arg));
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}
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#else
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#define hwdep_compat_ioctl NULL
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#endif
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static const struct snd_hwdep_ops hwdep_ops = {
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.read = hwdep_read,
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.write = hwdep_write,
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.release = hwdep_release,
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.poll = hwdep_poll,
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.ioctl = hwdep_ioctl,
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.ioctl_compat = hwdep_compat_ioctl,
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};
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int snd_efw_create_hwdep_device(struct snd_efw *efw)
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{
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struct snd_hwdep *hwdep;
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int err;
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err = snd_hwdep_new(efw->card, "Fireworks", 0, &hwdep);
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if (err < 0)
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goto end;
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strcpy(hwdep->name, "Fireworks");
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hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREWORKS;
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hwdep->ops = hwdep_ops;
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hwdep->private_data = efw;
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hwdep->exclusive = true;
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end:
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return err;
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}
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