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Diffstat (limited to 'include')
| -rw-r--r-- | include/tinyalsa/plugin.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/include/tinyalsa/plugin.h b/include/tinyalsa/plugin.h new file mode 100644 index 0000000..87bdaa0 --- /dev/null +++ b/include/tinyalsa/plugin.h @@ -0,0 +1,154 @@ +/* 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 <stdint.h> +#include <stdlib.h> + +#include <sound/asound.h> + * entry point function. + * @ingroup libtinyalsa-pcm + */ +#define PCM_PLUGIN_OPEN_FN_PTR() \ + int (*plugin_open_fn) (struct pcm_plugin **plugin, \ + unsigned int card, \ + unsigned int device, \ + int mode); +/** Forward declaration of the structure to hold pcm + * plugin related data/information. + */ +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); +}; + +/** 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; +}; + + +/** 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 */ |