147 lines
4.0 KiB
C
147 lines
4.0 KiB
C
/* pcm_hw.c
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**
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** Copyright (c) 2019, The Linux Foundation. All rights reserved.
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**
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** Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above
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** copyright notice, this list of conditions and the following
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** disclaimer in the documentation and/or other materials provided
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** with the distribution.
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** * Neither the name of The Linux Foundation nor the names of its
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** contributors may be used to endorse or promote products derived
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** from this software without specific prior written permission.
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**
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** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
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** ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
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** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
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** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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**/
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <stdarg.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <poll.h>
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#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <linux/ioctl.h>
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#include <sound/asound.h>
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#include <tinyalsa/asoundlib.h>
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#include "pcm_io.h"
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struct pcm_hw_data {
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unsigned int card;
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unsigned int device;
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unsigned int fd;
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void *snd_node;
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};
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static void pcm_hw_close(void *data)
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{
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struct pcm_hw_data *hw_data = data;
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if (hw_data->fd >= 0)
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close(hw_data->fd);
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free(hw_data);
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}
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static int pcm_hw_ioctl(void *data, unsigned int cmd, ...)
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{
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struct pcm_hw_data *hw_data = data;
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va_list ap;
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void *arg;
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va_start(ap, cmd);
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arg = va_arg(ap, void *);
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va_end(ap);
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return ioctl(hw_data->fd, cmd, arg);
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}
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static int pcm_hw_poll(void *data __attribute__((unused)),
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struct pollfd *pfd, nfds_t nfds, int timeout)
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{
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return poll(pfd, nfds, timeout);
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}
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static void* pcm_hw_mmap(void *data, void *addr, size_t length, int prot,
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int flags, off_t offset)
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{
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struct pcm_hw_data *hw_data = data;
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return mmap(addr, length, prot, flags, hw_data->fd, offset);
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}
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static int pcm_hw_munmap(void *data __attribute__((unused)), void *addr, size_t length)
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{
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return munmap(addr, length);
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}
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static int pcm_hw_open(unsigned int card, unsigned int device,
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unsigned int flags, void **data,
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__attribute__((unused)) void *node)
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{
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struct pcm_hw_data *hw_data;
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char fn[256];
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int fd;
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hw_data = calloc(1, sizeof(*hw_data));
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if (!hw_data) {
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return -ENOMEM;
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}
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snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
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flags & PCM_IN ? 'c' : 'p');
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fd = open(fn, O_RDWR|O_NONBLOCK);
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if (fd < 0) {
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printf("%s: cannot open device '%s'", __func__, fn);
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return fd;
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}
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if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK) < 0) {
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printf("%s: failed to reset blocking mode '%s'",
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__func__, fn);
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goto err_close;
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}
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hw_data->snd_node = node;
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hw_data->card = card;
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hw_data->device = device;
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hw_data->fd = fd;
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*data = hw_data;
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return fd;
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err_close:
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close(fd);
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free(hw_data);
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return -ENODEV;
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}
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struct pcm_ops hw_ops = {
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.open = pcm_hw_open,
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.close = pcm_hw_close,
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.ioctl = pcm_hw_ioctl,
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.mmap = pcm_hw_mmap,
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.munmap = pcm_hw_munmap,
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.poll = pcm_hw_poll,
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};
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