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/* plugin.h
** Copyright (c) 2019-2020, The Linux Foundation.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above
** copyright notice, this list of conditions and the following
** disclaimer in the documentation and/or other materials provided
** with the distribution.
** * Neither the name of The Linux Foundation nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
** ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**/
#ifndef TINYALSA_PLUGIN_H
#define TINYALSA_PLUGIN_H
#include <poll.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/types.h>
#include <time.h>
#include <sound/asound.h>
/* static initializers */
#define SND_VALUE_ENUM(etexts, eitems) \
{.texts = etexts, .items = eitems}
#define SND_VALUE_BYTES(csize) \
{.size = csize }
#define SND_VALUE_INTEGER(icount, imin, imax, istep) \
{.count = icount, .min = imin, .max = imax, .step = istep }
#define SND_VALUE_TLV_BYTES(csize, cget, cput) \
{.size = csize, .get = cget, .put = cput }
/* pointer based initializers */
#define INIT_SND_CONTROL_INTEGER(c, cname, cget, cput, cint, pval, pdata) \
{ \
c->iface = SNDRV_CTL_ELEM_IFACE_MIXER; \
c->access = SNDRV_CTL_ELEM_ACCESS_READWRITE; \
c->type = SNDRV_CTL_ELEM_TYPE_INTEGER; \
c->name = cname; c->value = &cint; c->get = cget; c->put = cput; \
c->private_value = pval; c->private_data = pdata; \
}
#define INIT_SND_CONTROL_BYTES(c, cname, cget, cput, cint, pval, pdata) \
{ \
c->iface = SNDRV_CTL_ELEM_IFACE_MIXER; \
c->access = SNDRV_CTL_ELEM_ACCESS_READWRITE; \
c->type = SNDRV_CTL_ELEM_TYPE_BYTES; \
c->name = cname; c->value = &cint; c->get = cget; c->put = cput; \
c->private_value = pval; c->private_data = pdata; \
}
#define INIT_SND_CONTROL_ENUM(c, cname, cget, cput, cenum, pval, pdata) \
{ \
c->iface = SNDRV_CTL_ELEM_IFACE_MIXER; \
c->access = SNDRV_CTL_ELEM_ACCESS_READWRITE; \
c->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED; \
c->name = cname; c->value = cenum; c->get = cget; c->put = cput; \
c->private_value = pval; c->private_data = pdata; \
}
#define INIT_SND_CONTROL_TLV_BYTES(c, cname, cbytes, priv_val, priv_data) \
{ \
c->iface = SNDRV_CTL_ELEM_IFACE_MIXER; \
c->access = SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE; \
c->type = SNDRV_CTL_ELEM_TYPE_BYTES; \
c->name = cname; c->value = &cbytes; \
c->private_value = priv_val; c->private_data = priv_data; \
}
struct mixer_plugin;
struct pcm_plugin;
struct snd_node;
/** Operations that are required to be registered by the plugin.
* @ingroup libtinyalsa-pcm
*/
struct pcm_plugin_ops {
/** open the pcm plugin */
int (*open) (struct pcm_plugin **plugin, unsigned int card,
unsigned int device, unsigned int flags);
/** close the pcm plugin */
int (*close) (struct pcm_plugin *plugin);
/** Set the PCM hardware parameters to the plugin */
int (*hw_params) (struct pcm_plugin *plugin,
struct snd_pcm_hw_params *params);
/** Set the PCM software parameters to the plugin */
int (*sw_params) (struct pcm_plugin *plugin,
struct snd_pcm_sw_params *params);
/** Synchronize the pointer */
int (*sync_ptr) (struct pcm_plugin *plugin,
struct snd_pcm_sync_ptr *sync_ptr);
/** Write frames to plugin to be rendered to output */
int (*writei_frames) (struct pcm_plugin *plugin,
struct snd_xferi *x);
/** Read frames from plugin captured from input */
int (*readi_frames) (struct pcm_plugin *plugin,
struct snd_xferi *x);
/** Obtain the timestamp for the PCM */
int (*ttstamp) (struct pcm_plugin *plugin,
int *tstamp);
/** Prepare the plugin for data transfer */
int (*prepare) (struct pcm_plugin *plugin);
/** Start data transfer from/to the plugin */
int (*start) (struct pcm_plugin *plugin);
/** Drop pcm frames */
int (*drop) (struct pcm_plugin *plugin);
/** Any custom or alsa specific ioctl implementation */
int (*ioctl) (struct pcm_plugin *plugin,
int cmd, void *arg);
void *(*mmap) (struct pcm_plugin *plugin, void *addr, size_t length,
int prot, int flags, off_t offset);
int (*munmap) (struct pcm_plugin *plugin, void *addr, size_t length);
int (*poll) (struct pcm_plugin *plugin, struct pollfd *pfd, nfds_t nfds,
int timeout);
};
/** Minimum and maximum values for hardware parameter constraints.
* @ingroup libtinyalsa-pcm
*/
struct pcm_plugin_min_max {
/** Minimum value for the hardware parameter */
unsigned int min;
/** Maximum value for the hardware parameter */
unsigned int max;
};
/** Encapsulate the hardware parameter constraints
* @ingroup libtinyalsa-pcm
*/
struct pcm_plugin_hw_constraints {
/** Value for SNDRV_PCM_HW_PARAM_ACCESS param */
uint64_t access;
/** Value for SNDRV_PCM_HW_PARAM_FORMAT param.
* As of this implementation ALSA supports 52 formats */
uint64_t format;
/** Value for SNDRV_PCM_HW_PARAM_SAMPLE_BITS param */
struct pcm_plugin_min_max bit_width;
/** Value for SNDRV_PCM_HW_PARAM_CHANNELS param */
struct pcm_plugin_min_max channels;
/** Value for SNDRV_PCM_HW_PARAM_RATE param */
struct pcm_plugin_min_max rate;
/** Value for SNDRV_PCM_HW_PARAM_PERIODS param */
struct pcm_plugin_min_max periods;
/** Value for SNDRV_PCM_HW_PARAM_PERIOD_BYTES param */
struct pcm_plugin_min_max period_bytes;
};
struct pcm_plugin {
/** Card number for the pcm device */
unsigned int card;
/** device number for the pcm device */
unsigned int device;
/** pointer to the contraints registered by the plugin */
struct pcm_plugin_hw_constraints *constraints;
/** Indicates read/write mode, etc.. */
int mode;
/* Pointer to hold the plugin's private data */
void *priv;
/* Tracks the plugin state */
unsigned int state;
};
typedef void (*mixer_event_callback)(struct mixer_plugin *);
struct mixer_plugin_ops {
int (*open) (struct mixer_plugin **plugin, unsigned int card);
void (*close) (struct mixer_plugin **plugin);
int (*subscribe_events) (struct mixer_plugin *plugin,
mixer_event_callback event_cb);
ssize_t (*read_event) (struct mixer_plugin *plugin,
struct snd_ctl_event *ev, size_t size);
};
struct snd_control {
snd_ctl_elem_iface_t iface;
unsigned int access;
const char *name;
snd_ctl_elem_type_t type;
void *value;
int (*get) (struct mixer_plugin *plugin,
struct snd_control *control,
struct snd_ctl_elem_value *ev);
int (*put) (struct mixer_plugin *plugin,
struct snd_control *control,
struct snd_ctl_elem_value *ev);
uint32_t private_value;
void *private_data;
};
struct mixer_plugin {
unsigned int card;
void *priv;
int eventfd;
int subscribed;
int event_cnt;
struct snd_control *controls;
unsigned int num_controls;
};
struct snd_value_enum {
unsigned int items;
char **texts;
};
struct snd_value_bytes {
unsigned int size;
};
struct snd_value_tlv_bytes {
unsigned int size;
int (*get) (struct mixer_plugin *plugin,
struct snd_control *control,
struct snd_ctl_tlv *tlv);
int (*put) (struct mixer_plugin *plugin,
struct snd_control *control,
struct snd_ctl_tlv *tlv);
};
struct snd_value_int {
unsigned int count;
int min;
int max;
int step;
};
/** Operations defined by the plugin.
* */
struct snd_node_ops {
/** Function pointer to get card definition */
void* (*open_card)(unsigned int card);
/** Function pointer to release card definition */
void (*close_card)(void *card);
/** Get interger type properties from device definition */
int (*get_int)(void *node, const char *prop, int *val);
/** Get string type properties from device definition */
int (*get_str)(void *node, const char *prop, char **val);
/** Function pointer to get mixer definition */
void* (*get_mixer)(void *card);
/** Function pointer to get PCM definition */
void* (*get_pcm)(void *card, unsigned int id);
/** Reserved for other nodes such as compress */
void* reserved[4];
};
#endif /* end of TINYALSA_PLUGIN_H */