diff options
Diffstat (limited to 'plugins/alsa/alsa-ctl.c')
| -rw-r--r-- | plugins/alsa/alsa-ctl.c | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/plugins/alsa/alsa-ctl.c b/plugins/alsa/alsa-ctl.c new file mode 100644 index 0000000..b469e94 --- /dev/null +++ b/plugins/alsa/alsa-ctl.c @@ -0,0 +1,399 @@ +/* + * Copyright(C) 2018 "IoT.bzh" + * Author Fulup Ar Foll <fulup@iot.bzh> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http : //www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License + +for the specific language governing permissions and + * limitations under the License. + * + * reference : + * https://github.com/zonque/simple-alsa-loop/blob/master/loop.c + * https://www.alsa-project.org/alsa-doc/alsa-lib/_2test_2pcm_8c-example.html#a31 + * + */ + +#define _GNU_SOURCE // needed for vasprintf + +#include "alsa-softmixer.h" +#include <pthread.h> +#include <sys/syscall.h> + +typedef struct { + AFB_ApiT api; + sd_event_source* evtsrc; + pthread_t thread; + int tid; + char* info; + snd_ctl_t *ctlDev; + sd_event *sdLoop; +} SubscribeHandleT; + +typedef struct { + snd_pcm_t *pcm[MAX_AUDIO_STREAMS+1]; + int numid[MAX_AUDIO_STREAMS+1]; + int count; +} AudioStreamHandleT; + +static AudioStreamHandleT AudioStreamHandle; + +// Clone of AlsaLib snd_card_load2 static function + +snd_ctl_card_info_t *AlsaCtlGetInfo(CtlSourceT *source, const char *devid) { + int error; + snd_ctl_t *ctlDev; + + if (devid) goto OnErrorExit; + + if ((error = snd_ctl_open(&ctlDev, devid, SND_CTL_READONLY)) < 0) { + devid = "Not Defined"; + goto OnErrorExit; + } + + snd_ctl_card_info_t *cardInfo = malloc(snd_ctl_card_info_sizeof()); + if ((error = snd_ctl_card_info(ctlDev, cardInfo)) < 0) { + goto OnErrorExit; + } + return cardInfo; + +OnErrorExit: + AFB_ApiError(source->api, "AlsaCtlGetInfo: fail to find sndcard by id= %s", devid); + return NULL; +} + +PUBLIC snd_ctl_t *AlsaCtlOpenCtl(CtlSourceT *source, const char *devid) { + int error; + snd_ctl_t *ctlDev; + + if (devid) goto OnErrorExit; + + if ((error = snd_ctl_open(&ctlDev, devid, SND_CTL_READONLY)) < 0) { + devid = "Not Defined"; + goto OnErrorExit; + } + + return ctlDev; + +OnErrorExit: + AFB_ApiError(source->api, "AlsaCtlOpenCtl: fail to find sndcard by id= %s", devid); + return NULL; +} + +STATIC int CtlElemIdGetInt (AFB_ApiT api, snd_ctl_t *ctlDev, snd_ctl_elem_id_t *elemId, long *value) { + int error; + snd_ctl_elem_value_t *elemData; + snd_ctl_elem_info_t *elemInfo; + + snd_ctl_elem_info_alloca(&elemInfo); + snd_ctl_elem_info_set_id(elemInfo, elemId); + if (snd_ctl_elem_info(ctlDev, elemInfo) < 0) goto OnErrorExit; + if (!snd_ctl_elem_info_is_readable(elemInfo)) goto OnErrorExit; + + // as we have static rate/channel we should have only one boolean as value + snd_ctl_elem_type_t elemType = snd_ctl_elem_info_get_type(elemInfo); + int count = snd_ctl_elem_info_get_count(elemInfo); + if (count != 1) goto OnErrorExit; + + snd_ctl_elem_value_alloca(&elemData); + snd_ctl_elem_value_set_id(elemData, elemId); + error = snd_ctl_elem_read(ctlDev, elemData); + if (error) goto OnSuccessExit; + + // value=1 when active and 0 when not active + *value = snd_ctl_elem_value_get_integer(elemData, 0); + +OnSuccessExit: + return 0; + +OnErrorExit: + + AFB_ApiWarning(api, "CtlSubscribeEventCB: ignored unsupported event Numid=%i", snd_ctl_elem_info_get_numid(elemInfo)); + for (int idx = 0; idx < count; idx++) { + long valueL; + + switch (elemType) { + case SND_CTL_ELEM_TYPE_BOOLEAN: + valueL = snd_ctl_elem_value_get_boolean(elemData, idx); + AFB_ApiNotice(api, "CtlElemIdGetBool: value=%ld", valueL); + break; + case SND_CTL_ELEM_TYPE_INTEGER: + valueL = snd_ctl_elem_value_get_integer(elemData, idx); + AFB_ApiNotice(api, "CtlElemIdGetInt: value=%ld", valueL); + break; + case SND_CTL_ELEM_TYPE_INTEGER64: + valueL = snd_ctl_elem_value_get_integer64(elemData, idx); + AFB_ApiNotice(api, "CtlElemIdGetInt64: value=%ld", valueL); + break; + case SND_CTL_ELEM_TYPE_ENUMERATED: + valueL = snd_ctl_elem_value_get_enumerated(elemData, idx); + AFB_ApiNotice(api, "CtlElemIdGetEnum: value=%ld", valueL); + break; + case SND_CTL_ELEM_TYPE_BYTES: + valueL = snd_ctl_elem_value_get_byte(elemData, idx); + AFB_ApiNotice(api, "CtlElemIdGetByte: value=%ld", valueL); + break; + case SND_CTL_ELEM_TYPE_IEC958: + default: + AFB_ApiNotice(api, "CtlElemIdGetInt: Unsupported type=%d", elemType); + break; + } + } + return -1; +} + +STATIC int CtlSubscribeEventCB(sd_event_source* src, int fd, uint32_t revents, void* userData) { + int error; + SubscribeHandleT *subscribeHandle = (SubscribeHandleT*) userData; + snd_ctl_event_t *eventId; + snd_ctl_elem_id_t *elemId; + snd_ctl_elem_info_t *elemInfo; + long value; + + if ((revents & EPOLLHUP) != 0) { + AFB_ApiNotice(subscribeHandle->api, "CtlSubscribeEventCB hanghup [card:%s disconnected]", subscribeHandle->info); + goto OnSuccessExit; + } + + if ((revents & EPOLLIN) == 0) goto OnSuccessExit; + + // initialise event structure on stack + snd_ctl_event_alloca(&eventId); + snd_ctl_elem_id_alloca(&elemId); + + error = snd_ctl_read(subscribeHandle->ctlDev, eventId); + if (error < 0) goto OnErrorExit; + + // we only process sndctrl element + if (snd_ctl_event_get_type(eventId) != SND_CTL_EVENT_ELEM) goto OnSuccessExit; + + // we only process value changed events + unsigned int eventMask = snd_ctl_event_elem_get_mask(eventId); + if (!(eventMask & SND_CTL_EVENT_MASK_VALUE)) goto OnSuccessExit; + + // extract element from event and get value + snd_ctl_event_elem_get_id(eventId, elemId); + error= CtlElemIdGetInt (subscribeHandle->api, subscribeHandle->ctlDev, elemId, &value); + if (error) goto OnErrorExit; + + // Fulup we have to reload info as elemId from event does not hold numid + snd_ctl_elem_info_alloca(&elemInfo); + snd_ctl_elem_info_set_id(elemInfo, elemId); + if (snd_ctl_elem_info(subscribeHandle->ctlDev, elemInfo) < 0) goto OnErrorExit; + int numid= snd_ctl_elem_info_get_numid(elemInfo); + + + for (int idx=0; idx < AudioStreamHandle.count; idx++) { + if (AudioStreamHandle.numid[idx] == numid) { + const char *pcmName = snd_pcm_name(AudioStreamHandle.pcm[idx]); + AFB_ApiNotice(subscribeHandle->api, "CtlSubscribeEventCB:%s/%d pcm=%s pause=%d numid=%d", subscribeHandle->info, subscribeHandle->tid, pcmName, !value, numid); + snd_pcm_pause(AudioStreamHandle.pcm[idx], !value); + break; + } + } + +OnSuccessExit: + return 0; + +OnErrorExit: + AFB_ApiWarning(subscribeHandle->api, "CtlSubscribeEventCB: ignored unsupported event"); + return 0; +} + +static void *LoopInThread(void *handle) { + SubscribeHandleT *subscribeHandle = (SubscribeHandleT*) handle; + int count = 0; + int watchdog = MAINLOOP_WATCHDOG * 1000; + subscribeHandle->tid = (int) syscall(SYS_gettid); + + AFB_ApiNotice(subscribeHandle->api, "LoopInThread:%s/%d Started", subscribeHandle->info, subscribeHandle->tid); + + /* loop until end */ + for (;;) { + int res = sd_event_run(subscribeHandle->sdLoop, watchdog); + if (res == 0) { + AFB_ApiNotice(subscribeHandle->api, "LoopInThread:%s/%d Idle count=%d", subscribeHandle->info, subscribeHandle->tid, count++); + continue; + } + if (res < 0) { + AFB_ApiError(subscribeHandle->api, "LoopInThread:%s/%d ERROR=%i Exit errno=%s", subscribeHandle->info, subscribeHandle->tid, res, strerror(res)); + break; + } + } + pthread_exit(0); +} + +PUBLIC snd_ctl_t* AlsaCrlFromPcm(CtlSourceT *source, snd_pcm_t *pcm) { + char buffer[32]; + int error; + snd_ctl_t *ctlDev; + snd_pcm_info_t *pcmInfo; + + snd_pcm_info_alloca(&pcmInfo); + if ((error = snd_pcm_info(pcm, pcmInfo)) < 0) goto OnErrorExit; + + int pcmCard = snd_pcm_info_get_card(pcmInfo); + snprintf(buffer, sizeof(buffer), "hw:%i", pcmCard); + if ((error = snd_ctl_open(&ctlDev, buffer, SND_CTL_READONLY)) < 0) goto OnErrorExit; + + return ctlDev; + +OnErrorExit: + return NULL; +} + +PUBLIC snd_ctl_elem_id_t * AlsaCtlGetElemId(CtlSourceT *source, snd_ctl_t* ctlDev, int numid) { + char string[32]; + int error; + int index; + snd_ctl_elem_list_t *ctlList = NULL; + snd_ctl_elem_id_t *elemId; + + snd_ctl_elem_list_alloca(&ctlList); + + if ((error = snd_ctl_elem_list(ctlDev, ctlList)) < 0) { + AFB_ApiError(source->api, "AlsaCtlElemIdGetInt [%s] fail retrieve controls", AlsaCtlUID (ctlDev, string)); + goto OnErrorExit; + } + + if ((error = snd_ctl_elem_list_alloc_space(ctlList, snd_ctl_elem_list_get_count(ctlList))) < 0) { + AFB_ApiError(source->api, "AlsaCtlElemIdGetInt [%s] fail retrieve count", AlsaCtlUID (ctlDev, string)); + goto OnErrorExit; + } + + // Fulup: do not understand why snd_ctl_elem_list should be call twice to get a valid ctlCount + if ((error = snd_ctl_elem_list(ctlDev, ctlList)) < 0) { + AFB_ApiError(source->api, "AlsaCtlElemIdGetInt [%s] fail retrieve controls", AlsaCtlUID (ctlDev, string)); + goto OnErrorExit; + } + + // loop on control to find the right one + int ctlCount = snd_ctl_elem_list_get_used(ctlList); + for (index = 0; index < ctlCount; index++) { + + if (numid == snd_ctl_elem_list_get_numid(ctlList, index)) { + snd_ctl_elem_id_malloc(&elemId); + snd_ctl_elem_list_get_id(ctlList, index, elemId); + break; + } + } + + if (index == ctlCount) { + AFB_ApiError(source->api, "AlsaCtlRegister [%s] fail get numid=%i count", AlsaCtlUID (ctlDev, string), numid); + goto OnErrorExit; + } + + // clear ctl list and return elemid + snd_ctl_elem_list_clear(ctlList); + return elemId; + +OnErrorExit: + if (ctlList) snd_ctl_elem_list_clear(ctlList); + return NULL; +} + + +PUBLIC int AlsaCtlSubscribe(CtlSourceT *source, snd_ctl_t * ctlDev) { + int error; + char string [32]; + struct pollfd pfds; + SubscribeHandleT *subscribeHandle = malloc(sizeof (SubscribeHandleT)); + + subscribeHandle->api = source->api; + subscribeHandle->ctlDev = ctlDev; + subscribeHandle->info = "ctlEvt"; + + // subscribe for sndctl events attached to devid + if ((error = snd_ctl_subscribe_events(ctlDev, 1)) < 0) { + AFB_ApiError(source->api, "AlsaCtlSubscribe: fail sndcard=%s to subscribe events", AlsaCtlUID(ctlDev, string)); + goto OnErrorExit; + } + + // get pollfd attach to this sound board + int count = snd_ctl_poll_descriptors(ctlDev, &pfds, 1); + if (count != 1) { + AFB_ApiError(source->api, "AlsaCtlSubscribe: fail sndcard=%s get poll descriptors", AlsaCtlUID(ctlDev, string)); + goto OnErrorExit; + } + + // add poll descriptor to AGL systemd mainloop + if ((error = sd_event_new(&subscribeHandle->sdLoop)) < 0) { + fprintf(stderr, "AlsaCtlSubscribe: fail sndcard=%s creating a new loop", AlsaCtlUID(ctlDev, string)); + goto OnErrorExit; + } + + // register sound event to binder main loop + if ((error = sd_event_add_io(subscribeHandle->sdLoop, &subscribeHandle->evtsrc, pfds.fd, EPOLLIN, CtlSubscribeEventCB, subscribeHandle)) < 0) { + AFB_ApiError(source->api, "AlsaCtlSubscribe: Fail sndcard=%s adding mainloop", AlsaCtlUID(ctlDev, string)); + goto OnErrorExit; + } + + // start a thread with a mainloop to monitor Audio-Agent + if ((error = pthread_create(&subscribeHandle->thread, NULL, &LoopInThread, subscribeHandle)) < 0) { + AFB_ApiError(source->api, "AlsaCtlSubscribe: Fail sndcard=%s create waiting thread err=%d", AlsaCtlUID(ctlDev, string), error); + goto OnErrorExit; + } + + return 0; + +OnErrorExit: + return -1; +} + +PUBLIC int AlsaCtlRegister(CtlSourceT *source, snd_pcm_t *pcm, int numid) { + long value; + int error; + + // NumID are attached to sndcard retrieve ctldev from PCM + snd_ctl_t* ctlDev = AlsaCrlFromPcm(source, pcm); + if (!ctlDev) { + AFB_ApiError(source->api, "AlsaCtlRegister [pcm=%s] fail attache sndcard", snd_pcm_name(pcm)); + goto OnErrorExit; + } + + // This is the first registration let's subscrive to event + if (AudioStreamHandle.count == 0) { + AlsaCtlSubscribe (source, ctlDev); + } + + snd_ctl_elem_id_t *elemId= AlsaCtlGetElemId(source, ctlDev, numid); + if (!elemId) { + AFB_ApiError(source->api, "AlsaCtlRegister [pcm=%s] fail to find numid=%d", snd_pcm_name(pcm), numid); + goto OnErrorExit; + } + + if ((error = CtlElemIdGetInt (source->api, ctlDev, elemId, &value)) != 0) { + AFB_ApiError(source->api, "AlsaCtlRegister [pcm=%s] fail to get numid=%d value", snd_pcm_name(pcm), numid); + goto OnErrorExit; + } + + AFB_ApiNotice(source->api, "AlsaCtlRegister [pcm=%s] numid=%d value=%ld", snd_pcm_name(pcm), numid, value); + + // store PCM in order to pause/resume depending on event + AudioStreamHandle.pcm[AudioStreamHandle.count] = pcm; + AudioStreamHandle.numid[AudioStreamHandle.count] = numid; + AudioStreamHandle.count++; + + // we only need to keep ctldev open for initial registration + if (AudioStreamHandle.count >1) snd_ctl_close(ctlDev); + + // toggle pause/resume (should be done after pcm_start) + if ((error = snd_pcm_pause(pcm, !value)) < 0) { + AFB_ApiError(source->api, "AlsaCtlRegister [pcm=%s] fail to pause", snd_pcm_name(pcm)); + goto OnErrorExit; + } + + return 0; + +OnErrorExit: + + return -1; +} |