Merge pull request #137 from codeauroraforum/plugin-support

Plugin support

1 files changed, 261 insertions, 0 deletions

diff --git a/include/tinyalsa/plugin.h b/include/tinyalsa/plugin.h
new file mode 100644
index 0000000..fed50be
--- /dev/null
+++ b/include/tinyalsa/plugin.h
@@ -0,0 +1,261 @@
+/* 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>
+
+/* 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);
+};
+
+/** 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 */