diff options
Diffstat (limited to '')
-rw-r--r-- | sound/firewire/fireworks/fireworks_hwdep.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/sound/firewire/fireworks/fireworks_hwdep.c b/sound/firewire/fireworks/fireworks_hwdep.c new file mode 100644 index 000000000..3a5391427 --- /dev/null +++ b/sound/firewire/fireworks/fireworks_hwdep.c @@ -0,0 +1,330 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * fireworks_hwdep.c - a part of driver for Fireworks based devices + * + * Copyright (c) 2013-2014 Takashi Sakamoto + */ + +/* + * This codes have five functionalities. + * + * 1.get information about firewire node + * 2.get notification about starting/stopping stream + * 3.lock/unlock streaming + * 4.transmit command of EFW transaction + * 5.receive response of EFW transaction + * + */ + +#include "fireworks.h" + +static long +hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained, + loff_t *offset) +{ + unsigned int length, till_end, type; + struct snd_efw_transaction *t; + u8 *pull_ptr; + long count = 0; + + if (remained < sizeof(type) + sizeof(struct snd_efw_transaction)) + return -ENOSPC; + + /* data type is SNDRV_FIREWIRE_EVENT_EFW_RESPONSE */ + type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE; + if (copy_to_user(buf, &type, sizeof(type))) + return -EFAULT; + count += sizeof(type); + remained -= sizeof(type); + buf += sizeof(type); + + /* write into buffer as many responses as possible */ + spin_lock_irq(&efw->lock); + + /* + * When another task reaches here during this task's access to user + * space, it picks up current position in buffer and can read the same + * series of responses. + */ + pull_ptr = efw->pull_ptr; + + while (efw->push_ptr != pull_ptr) { + t = (struct snd_efw_transaction *)(pull_ptr); + length = be32_to_cpu(t->length) * sizeof(__be32); + + /* confirm enough space for this response */ + if (remained < length) + break; + + /* copy from ring buffer to user buffer */ + while (length > 0) { + till_end = snd_efw_resp_buf_size - + (unsigned int)(pull_ptr - efw->resp_buf); + till_end = min_t(unsigned int, length, till_end); + + spin_unlock_irq(&efw->lock); + + if (copy_to_user(buf, pull_ptr, till_end)) + return -EFAULT; + + spin_lock_irq(&efw->lock); + + pull_ptr += till_end; + if (pull_ptr >= efw->resp_buf + snd_efw_resp_buf_size) + pull_ptr -= snd_efw_resp_buf_size; + + length -= till_end; + buf += till_end; + count += till_end; + remained -= till_end; + } + } + + /* + * All of tasks can read from the buffer nearly simultaneously, but the + * last position for each task is different depending on the length of + * given buffer. Here, for simplicity, a position of buffer is set by + * the latest task. It's better for a listening application to allow one + * thread to read from the buffer. Unless, each task can read different + * sequence of responses depending on variation of buffer length. + */ + efw->pull_ptr = pull_ptr; + + spin_unlock_irq(&efw->lock); + + return count; +} + +static long +hwdep_read_locked(struct snd_efw *efw, char __user *buf, long count, + loff_t *offset) +{ + union snd_firewire_event event = { + .lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS, + }; + + spin_lock_irq(&efw->lock); + + event.lock_status.status = (efw->dev_lock_count > 0); + efw->dev_lock_changed = false; + + spin_unlock_irq(&efw->lock); + + count = min_t(long, count, sizeof(event.lock_status)); + + if (copy_to_user(buf, &event, count)) + return -EFAULT; + + return count; +} + +static long +hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, + loff_t *offset) +{ + struct snd_efw *efw = hwdep->private_data; + DEFINE_WAIT(wait); + bool dev_lock_changed; + bool queued; + + spin_lock_irq(&efw->lock); + + dev_lock_changed = efw->dev_lock_changed; + queued = efw->push_ptr != efw->pull_ptr; + + while (!dev_lock_changed && !queued) { + prepare_to_wait(&efw->hwdep_wait, &wait, TASK_INTERRUPTIBLE); + spin_unlock_irq(&efw->lock); + schedule(); + finish_wait(&efw->hwdep_wait, &wait); + if (signal_pending(current)) + return -ERESTARTSYS; + spin_lock_irq(&efw->lock); + dev_lock_changed = efw->dev_lock_changed; + queued = efw->push_ptr != efw->pull_ptr; + } + + spin_unlock_irq(&efw->lock); + + if (dev_lock_changed) + count = hwdep_read_locked(efw, buf, count, offset); + else if (queued) + count = hwdep_read_resp_buf(efw, buf, count, offset); + + return count; +} + +static long +hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count, + loff_t *offset) +{ + struct snd_efw *efw = hwdep->private_data; + u32 seqnum; + u8 *buf; + + if (count < sizeof(struct snd_efw_transaction) || + SND_EFW_RESPONSE_MAXIMUM_BYTES < count) + return -EINVAL; + + buf = memdup_user(data, count); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + /* check seqnum is not for kernel-land */ + seqnum = be32_to_cpu(((struct snd_efw_transaction *)buf)->seqnum); + if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX) { + count = -EINVAL; + goto end; + } + + if (snd_efw_transaction_cmd(efw->unit, buf, count) < 0) + count = -EIO; +end: + kfree(buf); + return count; +} + +static __poll_t +hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait) +{ + struct snd_efw *efw = hwdep->private_data; + __poll_t events; + + poll_wait(file, &efw->hwdep_wait, wait); + + spin_lock_irq(&efw->lock); + if (efw->dev_lock_changed || efw->pull_ptr != efw->push_ptr) + events = EPOLLIN | EPOLLRDNORM; + else + events = 0; + spin_unlock_irq(&efw->lock); + + return events | EPOLLOUT; +} + +static int +hwdep_get_info(struct snd_efw *efw, void __user *arg) +{ + struct fw_device *dev = fw_parent_device(efw->unit); + struct snd_firewire_get_info info; + + memset(&info, 0, sizeof(info)); + info.type = SNDRV_FIREWIRE_TYPE_FIREWORKS; + 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_efw *efw) +{ + int err; + + spin_lock_irq(&efw->lock); + + if (efw->dev_lock_count == 0) { + efw->dev_lock_count = -1; + err = 0; + } else { + err = -EBUSY; + } + + spin_unlock_irq(&efw->lock); + + return err; +} + +static int +hwdep_unlock(struct snd_efw *efw) +{ + int err; + + spin_lock_irq(&efw->lock); + + if (efw->dev_lock_count == -1) { + efw->dev_lock_count = 0; + err = 0; + } else { + err = -EBADFD; + } + + spin_unlock_irq(&efw->lock); + + return err; +} + +static int +hwdep_release(struct snd_hwdep *hwdep, struct file *file) +{ + struct snd_efw *efw = hwdep->private_data; + + spin_lock_irq(&efw->lock); + if (efw->dev_lock_count == -1) + efw->dev_lock_count = 0; + spin_unlock_irq(&efw->lock); + + return 0; +} + +static int +hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct snd_efw *efw = hwdep->private_data; + + switch (cmd) { + case SNDRV_FIREWIRE_IOCTL_GET_INFO: + return hwdep_get_info(efw, (void __user *)arg); + case SNDRV_FIREWIRE_IOCTL_LOCK: + return hwdep_lock(efw); + case SNDRV_FIREWIRE_IOCTL_UNLOCK: + return hwdep_unlock(efw); + 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_efw_create_hwdep_device(struct snd_efw *efw) +{ + static const struct snd_hwdep_ops ops = { + .read = hwdep_read, + .write = hwdep_write, + .release = hwdep_release, + .poll = hwdep_poll, + .ioctl = hwdep_ioctl, + .ioctl_compat = hwdep_compat_ioctl, + }; + struct snd_hwdep *hwdep; + int err; + + err = snd_hwdep_new(efw->card, "Fireworks", 0, &hwdep); + if (err < 0) + goto end; + strcpy(hwdep->name, "Fireworks"); + hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREWORKS; + hwdep->ops = ops; + hwdep->private_data = efw; + hwdep->exclusive = true; +end: + return err; +} + |