diff options
Diffstat (limited to 'src/mixer_plugin.c')
| -rw-r--r-- | src/mixer_plugin.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/src/mixer_plugin.c b/src/mixer_plugin.c new file mode 100644 index 0000000..3437171 --- /dev/null +++ b/src/mixer_plugin.c @@ -0,0 +1,480 @@ +/* mixer_plugin.c +** Copyright (c) 2019, 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. +**/ + +#include <tinyalsa/plugin.h> + +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <stdarg.h> +#include <stdbool.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <ctype.h> +#include <poll.h> +#include <dlfcn.h> +#include <string.h> +#include <sys/eventfd.h> +#include <sys/ioctl.h> + +#include <linux/ioctl.h> +#include <sound/asound.h> + +#include "snd_card_plugin.h" +#include "mixer_io.h" + +/** Encapulates the mixer plugin specific data */ +struct mixer_plug_data { + /** Card number associated with the plugin */ + int card; + /** Device node for mixer */ + void *mixer_node; + /** Pointer to the plugin's ops */ + const struct mixer_plugin_ops *ops; + /** Pointer to plugin responsible to service the controls */ + struct mixer_plugin *plugin; + /** Handle to the plugin library */ + void *dl_hdl; +}; + +static int mixer_plug_get_elem_id(struct mixer_plug_data *plug_data, + struct snd_ctl_elem_id *id, unsigned int offset) +{ + struct mixer_plugin *plugin = plug_data->plugin; + struct snd_control *ctl; + + if (offset >= plugin->num_controls) { + fprintf(stderr, "%s: invalid offset %u\n", + __func__, offset); + return -EINVAL; + } + + ctl = plugin->controls + offset; + id->numid = offset; + id->iface = ctl->iface; + + strncpy((char *)id->name, (char *)ctl->name, + sizeof(id->name)); + + return 0; +} + +static int mixer_plug_info_enum(struct snd_control *ctl, + struct snd_ctl_elem_info *einfo) +{ + struct snd_value_enum *val = ctl->value; + + einfo->count = 1; + einfo->value.enumerated.items = val->items; + + if (einfo->value.enumerated.item > val->items) + return -EINVAL; + + strncpy(einfo->value.enumerated.name, + val->texts[einfo->value.enumerated.item], + sizeof(einfo->value.enumerated.name)); + + return 0; +} + +static int mixer_plug_info_bytes(struct snd_control *ctl, + struct snd_ctl_elem_info *einfo) +{ + struct snd_value_bytes *val; + struct snd_value_tlv_bytes *val_tlv; + + if (ctl->access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) { + val_tlv = ctl->value; + einfo->count = val_tlv->size; + } else { + val = ctl->value; + einfo->count = val->size; + } + + return 0; +} + +static int mixer_plug_info_integer(struct snd_control *ctl, + struct snd_ctl_elem_info *einfo) +{ + struct snd_value_int *val = ctl->value; + + einfo->count = val->count; + einfo->value.integer.min = val->min; + einfo->value.integer.max = val->max; + einfo->value.integer.step = val->step; + + return 0; +} + +void mixer_plug_notifier_cb(struct mixer_plugin *plugin) +{ + eventfd_write(plugin->eventfd, 1); + plugin->event_cnt++; +} + +/* In consume_event/read, do not call eventfd_read until all events are read from list. + This will make poll getting unblocked until all events are read */ +static ssize_t mixer_plug_read_event(void *data, struct snd_ctl_event *ev, size_t size) +{ + struct mixer_plug_data *plug_data = data; + struct mixer_plugin *plugin = plug_data->plugin; + eventfd_t evfd; + ssize_t result = 0; + + result = plug_data->ops->read_event(plugin, ev, size); + + if (result > 0) { + plugin->event_cnt -= result / sizeof(struct snd_ctl_event); + if (plugin->event_cnt == 0) + eventfd_read(plugin->eventfd, &evfd); + } + + return result; +} + +static int mixer_plug_subscribe_events(struct mixer_plug_data *plug_data, + int *subscribe) +{ + struct mixer_plugin *plugin = plug_data->plugin; + eventfd_t evfd; + + if (*subscribe < 0 || *subscribe > 1) { + *subscribe = plugin->subscribed; + return -EINVAL; + } + + if (*subscribe && !plugin->subscribed) { + plug_data->ops->subscribe_events(plugin, &mixer_plug_notifier_cb); + } else if (plugin->subscribed && !*subscribe) { + plug_data->ops->subscribe_events(plugin, NULL); + + if (plugin->event_cnt) + eventfd_read(plugin->eventfd, &evfd); + + plugin->event_cnt = 0; + } + + plugin->subscribed = *subscribe; + return 0; +} + +static int mixer_plug_get_poll_fd(void *data, struct pollfd *pfd, int count) +{ + struct mixer_plug_data *plug_data = data; + struct mixer_plugin *plugin = plug_data->plugin; + + if (plugin->eventfd != -1) { + pfd[count].fd = plugin->eventfd; + return 0; + } + return -ENODEV; +} + +static int mixer_plug_tlv_write(struct mixer_plug_data *plug_data, + struct snd_ctl_tlv *tlv) +{ + struct mixer_plugin *plugin = plug_data->plugin; + struct snd_control *ctl; + struct snd_value_tlv_bytes *val_tlv; + + ctl = plugin->controls + tlv->numid; + val_tlv = ctl->value; + + return val_tlv->put(plugin, ctl, tlv); +} + +static int mixer_plug_tlv_read(struct mixer_plug_data *plug_data, + struct snd_ctl_tlv *tlv) +{ + struct mixer_plugin *plugin = plug_data->plugin; + struct snd_control *ctl; + struct snd_value_tlv_bytes *val_tlv; + + ctl = plugin->controls + tlv->numid; + val_tlv = ctl->value; + + return val_tlv->get(plugin, ctl, tlv); +} + +static int mixer_plug_elem_write(struct mixer_plug_data *plug_data, + struct snd_ctl_elem_value *ev) +{ + struct mixer_plugin *plugin = plug_data->plugin; + struct snd_control *ctl; + int ret; + + ret = mixer_plug_get_elem_id(plug_data, &ev->id, ev->id.numid); + if (ret < 0) + return ret; + + ctl = plugin->controls + ev->id.numid; + + return ctl->put(plugin, ctl, ev); +} + +static int mixer_plug_elem_read(struct mixer_plug_data *plug_data, + struct snd_ctl_elem_value *ev) +{ + struct mixer_plugin *plugin = plug_data->plugin; + struct snd_control *ctl; + int ret; + + ret = mixer_plug_get_elem_id(plug_data, &ev->id, ev->id.numid); + if (ret < 0) + return ret; + + ctl = plugin->controls + ev->id.numid; + + return ctl->get(plugin, ctl, ev); + +} + +static int mixer_plug_get_elem_info(struct mixer_plug_data *plug_data, + struct snd_ctl_elem_info *einfo) +{ + struct mixer_plugin *plugin = plug_data->plugin; + struct snd_control *ctl; + int ret; + + ret = mixer_plug_get_elem_id(plug_data, &einfo->id, + einfo->id.numid); + if (ret < 0) + return ret; + + ctl = plugin->controls + einfo->id.numid; + einfo->type = ctl->type; + einfo->access = ctl->access; + + switch (einfo->type) { + case SNDRV_CTL_ELEM_TYPE_ENUMERATED: + ret = mixer_plug_info_enum(ctl, einfo); + if (ret < 0) + return ret; + break; + case SNDRV_CTL_ELEM_TYPE_BYTES: + ret = mixer_plug_info_bytes(ctl, einfo); + if (ret < 0) + return ret; + break; + case SNDRV_CTL_ELEM_TYPE_INTEGER: + ret = mixer_plug_info_integer(ctl, einfo); + if (ret < 0) + return ret; + break; + default: + fprintf(stderr,"%s: unknown type %d\n", + __func__, einfo->type); + return -EINVAL; + } + + return 0; +} + +static int mixer_plug_get_elem_list(struct mixer_plug_data *plug_data, + struct snd_ctl_elem_list *elist) +{ + struct mixer_plugin *plugin = plug_data->plugin; + unsigned int avail; + struct snd_ctl_elem_id *id; + int ret; + + elist->count = plugin->num_controls; + elist->used = 0; + avail = elist->space; + + while (avail > 0) { + id = elist->pids + elist->used; + ret = mixer_plug_get_elem_id(plug_data, id, elist->used); + if (ret < 0) + return ret; + + avail--; + elist->used++; + } + + return 0; +} + +static int mixer_plug_get_card_info(struct mixer_plug_data *plug_data, + struct snd_ctl_card_info *card_info) +{ + /*TODO: Fill card_info here from snd-card-def */ + memset(card_info, 0, sizeof(*card_info)); + card_info->card = plug_data->card; + memcpy(card_info->id, "card_id", sizeof(card_info->id)); + memcpy(card_info->driver, "mymixer-so-name", sizeof(card_info->driver)); + memcpy(card_info->name, "card-name", sizeof(card_info->name)); + memcpy(card_info->longname, "card-name", sizeof(card_info->longname)); + memcpy(card_info->mixername, "mixer-name", sizeof(card_info->mixername)); + + return 0; +} + +static void mixer_plug_close(void *data) +{ + struct mixer_plug_data *plug_data = data; + struct mixer_plugin *plugin = plug_data->plugin; + eventfd_t evfd; + + if (plugin->event_cnt) + eventfd_read(plugin->eventfd, &evfd); + + plug_data->ops->close(&plugin); + dlclose(plug_data->dl_hdl); + + free(plug_data); + plug_data = NULL; +} + +static int mixer_plug_ioctl(void *data, unsigned int cmd, ...) +{ + struct mixer_plug_data *plug_data = data; + int ret; + va_list ap; + void *arg; + + va_start(ap, cmd); + arg = va_arg(ap, void *); + va_end(ap); + + switch (cmd) { + case SNDRV_CTL_IOCTL_CARD_INFO: + ret = mixer_plug_get_card_info(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_ELEM_LIST: + ret = mixer_plug_get_elem_list(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_ELEM_INFO: + ret = mixer_plug_get_elem_info(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_ELEM_READ: + ret = mixer_plug_elem_read(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_ELEM_WRITE: + ret = mixer_plug_elem_write(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_TLV_READ: + ret = mixer_plug_tlv_read(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_TLV_WRITE: + ret = mixer_plug_tlv_write(plug_data, arg); + break; + case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS: + ret = mixer_plug_subscribe_events(plug_data, arg); + break; + default: + /* TODO: plugin should support ioctl */ + ret = -EFAULT; + break; + } + + return ret; +} + +static const struct mixer_ops mixer_plug_ops = { + .close = mixer_plug_close, + .read_event = mixer_plug_read_event, + .get_poll_fd = mixer_plug_get_poll_fd, + .ioctl = mixer_plug_ioctl, +}; + +int mixer_plugin_open(unsigned int card, void **data, + const struct mixer_ops **ops) +{ + struct mixer_plug_data *plug_data; + struct mixer_plugin *plugin = NULL; + void *dl_hdl; + char *so_name; + int ret; + + plug_data = calloc(1, sizeof(*plug_data)); + if (!plug_data) + return -ENOMEM; + + plug_data->mixer_node = snd_utils_open_mixer(card); + if (!plug_data->mixer_node) { + /* Do not print error here. + * It is valid for card to not have virtual mixer node + */ + goto err_get_mixer_node; + } + + ret = snd_utils_get_str(plug_data->mixer_node, "so-name", + &so_name); + if(ret) { + fprintf(stderr, "%s: mixer so-name not found for card %u\n", + __func__, card); + goto err_get_lib_name; + + } + + dl_hdl = dlopen(so_name, RTLD_NOW); + if (!dl_hdl) { + fprintf(stderr, "%s: unable to open %s\n", + __func__, so_name); + goto err_dlopen; + } + + dlerror(); + plug_data->ops = dlsym(dl_hdl, "mixer_plugin_ops"); + if (!plug_data->ops) { + fprintf(stderr, "%s: dlsym open fn failed: %s\n", + __func__, dlerror()); + goto err_ops; + } + + ret = plug_data->ops->open(&plugin, card); + if (ret) { + fprintf(stderr, "%s: failed to open plugin, err: %d\n", + __func__, ret); + goto err_ops; + } + + plug_data->plugin = plugin; + plug_data->card = card; + plug_data->dl_hdl = dl_hdl; + plugin->eventfd = eventfd(0, 0); + + *data = plug_data; + *ops = &mixer_plug_ops; + + return 0; + +err_ops: + dlclose(dl_hdl); +err_dlopen: +err_get_lib_name: + snd_utils_close_dev_node(plug_data->mixer_node); +err_get_mixer_node: + free(plug_data); + return -1; +} |