diff options
Diffstat (limited to 'Alsa-Plugin/_Alsa-Hal-plugin')
| -rw-r--r-- | Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h | 91 | ||||
| -rw-r--r-- | Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c | 66 | ||||
| -rw-r--r-- | Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c | 423 | ||||
| -rw-r--r-- | Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt | 55 | ||||
| -rw-r--r-- | Alsa-Plugin/_Alsa-Hal-plugin/README.md | 44 |
5 files changed, 679 insertions, 0 deletions
diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h new file mode 100644 index 0000000..bb2dd79 --- /dev/null +++ b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlug.h @@ -0,0 +1,91 @@ +/* + * Copyright (C) 2016 "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. + * + * AfbCallBack (snd_ctl_hal_t *handle, int numid, void **response); + * AfbHalInit is mandatory and called with numid=0 + * + * Syntaxe in .asoundrc file + * CrlLabel { cb MyFunctionName name "My_Second_Control" } + */ + + +#include <alsa/asoundlib.h> +#include <alsa/control_external.h> +#include <linux/soundcard.h> + +#ifndef SOUND_HAL_MAX_CTLS +#define SOUND_HAL_MAX_CTLS 255 +#endif + +typedef enum { + CTLCB_INIT, + CTLCB_CLOSE, + CTLCB_ELEM_COUNT, + CTLCB_ELEM_LIST, + CTLCB_FIND_ELEM, + CTLCB_FREE_KEY, + CTLCB_GET_ATTRIBUTE, + CTLCB_GET_INTEGER_INFO, + CTLCB_GET_INTEGER64_INFO, + CTLCB_GET_ENUMERATED_INFO, + CTLCB_GET_ENUMERATED_NAME, + CTLCB_READ_INTEGER, + CTLCB_READ_INTEGER64, + CTLCB_READ_ENUMERATED, + CTLCB_READ_BYTES, + CTLCB_READ_IEC958, + CTLCB_WRITE_INTEGER, + CTLCB_WRITE_INTEGER64, + CTLCB_WRITE_ENUMERATED, + CTLCB_WRITE_BYTES, + CTLCB_WRITE_IEC958, + CTLCB_SUBSCRIBE_EVENTS, + CTLCB_READ_EVENT, + CTLCB_POLL_DESCRIPTORS_COUNT, + CTLCB_POLL_DESCRIPTORS +} snd_ctl_action_t; + +typedef struct { + int ctlNumid; + const char *ctlName; +} snd_ctl_conf_t; + +typedef struct { + int type; + int acc; + unsigned count; +} snd_ctl_get_attrib_t; + +typedef struct { + int imin; + int imax; + int istep; +} snd_ctl_get_int_info_t; + +typedef int(*snd_ctl_cb_t)(void *handle, snd_ctl_action_t action, snd_ctl_ext_key_t key, void *response); + +typedef struct snd_ctl_hal { + snd_ctl_ext_t ext; + char *devid; + snd_ctl_t *ctlDev; + unsigned int ctlsCount; + void *dlHandle; + snd_ctl_conf_t ctls[SOUND_HAL_MAX_CTLS]; + snd_ctl_elem_info_t *infos[SOUND_HAL_MAX_CTLS]; + snd_ctl_cb_t cbs[SOUND_HAL_MAX_CTLS]; +} snd_ctl_hal_t; + + diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c new file mode 100644 index 0000000..b96f3d9 --- /dev/null +++ b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCb.c @@ -0,0 +1,66 @@ +/* + * Copyright (C) 2016 "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. + * + * AfbCallBack (snd_ctl_hal_t *handle, int numid, void **response); + * AfbHalInit is mandatory and called with numid=0 + * + * Syntax in .asoundrc file + * CrlLabel { cb MyFunctionName name "My_Second_Control" } + * + * Testing: + * amixer -Dagl_hal controls + * amixer -Dagl_hal cget name=My_Sample_Callback + */ + + +#include "AlsaHalPlug.h" +#include <stdio.h> + +int AfbHalInitCB(void *handle, snd_ctl_action_t action, int numid, void*response) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) handle; + + fprintf(stdout, "\n - CB AfbHalInit devid=%s\n", plughandle->devid); + return 0; +} + +int AfbHalSampleCB(void *handle, snd_ctl_action_t action, snd_ctl_ext_key_t key, void*response) { + + switch (action) { + case CTLCB_GET_ATTRIBUTE: + { + fprintf(stdout, " - AfbHalSampleCB CTLCB_GET_ATTRIBUTE numid=%d\n", (int) key + 1); + snd_ctl_get_attrib_t *item = (snd_ctl_get_attrib_t*) response; + item->type = 1; + item->count = 2; + item->acc = SND_CTL_EXT_ACCESS_READWRITE; + break; + } + + case CTLCB_GET_INTEGER_INFO: + { + fprintf(stdout, " - AfbHalSampleCB CTLCB_GET_INTEGER_INFO numid=%d\n", (int) key + 1); + snd_ctl_get_int_info_t *item = (snd_ctl_get_attrib_t*) response; + item->istep = 10; + item->imin = 20; + item->imax = 200; + break; + } + + default: + fprintf(stdout, "CB AfbHalSampleCB unsupported action=%d numid=%d\n", action, (int) key + 1); + } + return 0; +} diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c new file mode 100644 index 0000000..5e92dd6 --- /dev/null +++ b/Alsa-Plugin/_Alsa-Hal-plugin/AlsaHalPlugCtl.c @@ -0,0 +1,423 @@ +/* + * Copyright (C) 2016 "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. + * + * Testing: + * 1) Copy generated plugin [libasound_module_pcm_afbhal.so] in alsa-lib/ dir visible from LD_LIBRARY_PATH (eg: /usr/lib64/alsa-lib) + * 2) Create a ~/.asounrc file base on following template + * ctl.agl_hal { + * type afbhal + * devid "hw:4" + * cblib "afbhal_cb_sample.so" + * ctls { + * # ctlLabel {numid integer name "Alsa Ctl Name"} + * MasterSwitch { numid 4 name "My_First_Control" } + * MasterVol { numid 5 name "My_Second_Control" } + * CB_sample { ctlcb @AfbHalSampleCB name "My_Sample_Callback"} + * } + * pcm.agl_hal { + * type copy # Copy PCM + * slave "hw:4" # Slave name + * } + * + * } + * 3) Test with + * - amixer -Dagl_hal controls # should list all your controls + * - amixer -Dagl_hal cget numid=1 + * - amixer -Dagl_hal cset numid=1 '10,20' + */ + + +#include <stdio.h> +#include <sys/ioctl.h> +#include "AlsaHalPlug.h" +#include <dlfcn.h> + +static snd_ctl_ext_key_t AfbHalElemFind(snd_ctl_ext_t *ext, const snd_ctl_elem_id_t *id) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + snd_ctl_ext_key_t key = NULL; + + int numid = snd_ctl_elem_id_get_numid(id); + if (numid > 0) { + if (numid > plughandle->ctlsCount) goto OnErrorExit; + key = (snd_ctl_ext_key_t) numid - 1; + goto SucessExit; + } + + const char *ctlName = snd_ctl_elem_id_get_name(id); + if (ctlName == NULL) goto OnErrorExit; + + for (int idx = 0; idx < plughandle->ctlsCount; idx++) { + if (!strcmp(ctlName, plughandle->ctls[idx].ctlName)) { + key = idx; + goto SucessExit; + } + } + +SucessExit: + return key; + +OnErrorExit: + return -1; +} + +static int AfbHalGetAttrib(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, int *type, unsigned int *acc, unsigned int *count) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + snd_ctl_elem_info_t *elemInfo = plughandle->infos[key]; + snd_ctl_cb_t callback = plughandle->cbs[key]; + + + // search for equivalent NUMID in effective sound card + if (elemInfo) { + *type = snd_ctl_elem_info_get_type(elemInfo); + *count = snd_ctl_elem_info_get_count(elemInfo); + *acc = SND_CTL_EXT_ACCESS_READWRITE; // Future ToBeDone + return 0; + } + + if (callback) { + snd_ctl_get_attrib_t item; + + int err = callback(plughandle, CTLCB_GET_ATTRIBUTE, key, &item); + if (!err) { + *type = item.type; + *acc = item.acc; + *count = item.count; + } + return err; + } + + return -1; +} + +static int AfbHalGetIntInfo(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *imin, long *imax, long *istep) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + snd_ctl_elem_info_t *elemInfo = plughandle->infos[key]; + snd_ctl_cb_t callback = plughandle->cbs[key]; + + if (elemInfo) { + + // Should be normalised to make everything 0-100% + *imin = (long) snd_ctl_elem_info_get_min(elemInfo); + *imax = (long) snd_ctl_elem_info_get_min(elemInfo); + *istep = (long) snd_ctl_elem_info_get_min(elemInfo); + return 0; + } + + if (callback) { + snd_ctl_get_int_info_t item; + + int err = callback(plughandle, CTLCB_GET_INTEGER_INFO, key, &item); + if (!err) { + *imin = item.imin; + *imax = item.imax; + *istep = item.istep; + } + return err; + } + + return -1; +} + +static int AfbHalGetEnumInfo(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + snd_ctl_elem_info_t *elemInfo = plughandle->infos[key]; + snd_ctl_cb_t callback = plughandle->cbs[key]; + + if (elemInfo) *items = snd_ctl_elem_info_get_items(elemInfo); + if (callback) callback(plughandle, CTLCB_GET_ENUMERATED_INFO, key, items); + + return 0; +} + +static int AfbHalGetEnumName(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int item, char *name, size_t name_max_len) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + snd_ctl_elem_info_t *elemInfo = plughandle->infos[key]; + + //name= snd_ctl_elem_info_get_item_name(elemInfo); + return 0; +} + +static int AfbHalReadInt(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + snd_ctl_elem_info_t *elemInfo = plughandle->infos[key]; + + return 0; +} + +static int AfbHalReadEnumerate(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + + return 0; +} + +static int AfbHalWriteInt(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + + return 0; +} + +static int AfbHalWriteEnum(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + + return 0; +} + +static int AfbHalEventRead(snd_ctl_ext_t *ext, snd_ctl_elem_id_t *id, unsigned int *event_mask) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + + return -EAGAIN; +} + +static int AfbHalElemList(snd_ctl_ext_t *ext, unsigned int offset, snd_ctl_elem_id_t *id) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + + snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER); + snd_ctl_elem_id_set_name(id, plughandle->ctls[offset].ctlName); + + return 0; +} + +static int AfbHalElemCount(snd_ctl_ext_t *ext) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + int count = plughandle->ctlsCount; + return count; +} + +static void AfbHalClose(snd_ctl_ext_t *ext) { + snd_ctl_hal_t *plughandle = (snd_ctl_hal_t*) ext->private_data; + int err; + + for (int idx = 0; idx < plughandle->ctlsCount; idx++) { + if (plughandle->ctls[idx].ctlName) free((void*) plughandle->ctls[idx].ctlName); + } + + err = snd_ctl_close(plughandle->ctlDev); + if (err) SNDERR("Fail Close sndctl: devid=%s err=%s", plughandle->devid, snd_strerror(err)); + + if (plughandle->devid) free(plughandle->devid); + free(plughandle); +} + +static snd_ctl_ext_callback_t afbHalCBs = { + .close = AfbHalClose, + .elem_count = AfbHalElemCount, + .elem_list = AfbHalElemList, + .find_elem = AfbHalElemFind, + .get_attribute = AfbHalGetAttrib, + .get_integer_info = AfbHalGetIntInfo, + .get_enumerated_info = AfbHalGetEnumInfo, + .get_enumerated_name = AfbHalGetEnumName, + .read_integer = AfbHalReadInt, + .read_enumerated = AfbHalReadEnumerate, + .write_integer = AfbHalWriteInt, + .write_enumerated = AfbHalWriteEnum, + .read_event = AfbHalEventRead, +}; + +SND_CTL_PLUGIN_DEFINE_FUNC(afbhal) { + + snd_config_iterator_t it, next; + snd_ctl_hal_t *plughandle; + int err; + snd_ctl_cb_t AfbHalInitCB; + const char *libname; + + plughandle = calloc(1, sizeof (snd_ctl_hal_t)); + + snd_config_for_each(it, next, conf) { + snd_config_t *node = snd_config_iterator_entry(it); + const char *id; + + // ignore comment en empty lines + if (snd_config_get_id(node, &id) < 0) continue; + if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0 || strcmp(id, "hint") == 0) continue; + + // devid should point onto a valid sound card + if (strcmp(id, "devid") == 0) { + const char *devid; + if (snd_config_get_string(node, &devid) < 0) { + SNDERR("Invalid string type for %s", id); + return -EINVAL; + } + plughandle->devid = strdup(devid); + + // open control interface for devid + err = snd_ctl_open(&plughandle->ctlDev, plughandle->devid, 0); + if (err < 0) { + SNDERR("Fail to open control device for devid=%s", plughandle->devid); + return -EINVAL; + } + continue; + } + + if (strcmp(id, "cblib") == 0) { + if (snd_config_get_string(node, &libname) < 0) { + SNDERR("Invalid libname string for %s", id); + return -EINVAL; + } + + plughandle->dlHandle = dlopen(libname, RTLD_NOW); + if (!plughandle->dlHandle) { + SNDERR("Fail to open callback sharelib=%s error=%s", libname, dlerror()); + return -EINVAL; + } + + AfbHalInitCB = dlsym(plughandle->dlHandle, "AfbHalInitCB"); + if (!AfbHalInitCB) { + SNDERR("Fail find 'AfbHalInitCB' symbol into callbacks sharelib=%s", libname); + return -EINVAL; + } + + err = (*AfbHalInitCB)(plughandle, CTLCB_INIT, 0, 0); + if (err) { + SNDERR("Fail AfbHalInitCB err=%d", err); + return -EINVAL; + } + + continue; + } + + if (strcmp(id, "ctl") == 0) { + const char *ctlConf; + snd_config_type_t ctype; + snd_config_iterator_t currentCtl, follow; + snd_config_t *itemConf; + + ctype = snd_config_get_type(node); + if (ctype != SND_CONFIG_TYPE_COMPOUND) { + snd_config_get_string(node, &ctlConf); + SNDERR("Invalid compound type for %s", node); + return -EINVAL; + } + + // loop on each ctl within ctls + + snd_config_for_each(currentCtl, follow, node) { + snd_config_t *ctlconfig = snd_config_iterator_entry(currentCtl); + snd_ctl_elem_info_t *elemInfo; + const char *ctlLabel, *ctlName; + + // ignore empty line + if (snd_config_get_id(ctlconfig, &ctlLabel) < 0) continue; + + // each clt should be a valid config compound + ctype = snd_config_get_type(ctlconfig); + if (ctype != SND_CONFIG_TYPE_COMPOUND) { + snd_config_get_string(node, &ctlConf); + SNDERR("Invalid ctl config for %s", ctlLabel); + return -EINVAL; + } + + err = snd_config_search(ctlconfig, "ctl", &itemConf); + if (!err) { + if (snd_config_get_integer(itemConf, (long*) &plughandle->ctls[plughandle->ctlsCount].ctlNumid) < 0) { + SNDERR("Not Integer: ctl:%s numid should be a valid integer", ctlLabel); + return -EINVAL; + } + + // Make sure than numid is valid on slave snd card + snd_ctl_elem_info_malloc(&elemInfo); + snd_ctl_elem_info_set_numid(elemInfo, (int) plughandle->ctls[plughandle->ctlsCount].ctlNumid); + plughandle->infos[plughandle->ctlsCount] = elemInfo; + + err = snd_ctl_elem_info(plughandle->ctlDev, elemInfo); + if (err) { + SNDERR("Not Found: 'numid=%d' for 'devid=%s'", plughandle->ctls[plughandle->ctlsCount].ctlNumid, plughandle->devid); + return -EINVAL; + } + } + + err = snd_config_search(ctlconfig, "ctlcb", &itemConf); + if (!err) { + const char *funcname; + void *funcaddr; + + if (snd_config_get_string(itemConf, &funcname) < 0) { + SNDERR("Not string: ctl:%s cbname should be a valid string", ctlLabel); + return -EINVAL; + } + + if (funcname[0] != '@') { + SNDERR("Not string: ctl:%s cbname=%s should be prefixed with '@' ", ctlLabel, funcname); + return -EINVAL; + } + + if (!plughandle->dlHandle) { + SNDERR("No CB: ctl:%s cblib:/my/libcallback missing from asoundrc", ctlLabel); + return -EINVAL; + } + + funcaddr = dlsym(plughandle->dlHandle, &funcname[1]); + if (!funcaddr) { + SNDERR("NotFound CB: ctl:%s cbname='%s' no symbol into %s", ctlLabel, &funcname[1], libname); + return -EINVAL; + } + plughandle->cbs[plughandle->ctlsCount] = funcaddr; + } + + err = snd_config_search(ctlconfig, "name", &itemConf); + if (err) { + SNDERR("Not Found: 'name' mandatory in ctl config"); + return -EINVAL; + } + + if (snd_config_get_string(itemConf, &ctlName) < 0) { + SNDERR("Not String: ctl:%s 'name' should be a valie string", ctlLabel); + return -EINVAL; + } + plughandle->ctls[plughandle->ctlsCount].ctlName = strdup(ctlName); + + // move to next ctl if any + plughandle->ctlsCount++; + } // end for each ctl + continue; + } + SNDERR("Unknown field %s", id); + return -EINVAL; + } + + + + // Create ALSA control plugin structure + plughandle->ext.version = SND_CTL_EXT_VERSION; + plughandle->ext.card_idx = 0; /* FIXME */ + strcpy(plughandle->ext.id, "AFB-HAL-CTL"); + strcpy(plughandle->ext.driver, "AFB-HAL"); + strcpy(plughandle->ext.name, "AFB-HAL Control Plugin"); + strcpy(plughandle->ext.mixername, "AFB-HAL Mixer Plugin"); + strcpy(plughandle->ext.longname, "Automotive-Linux Sound Abstraction Control Plugin"); + plughandle->ext.poll_fd = -1; + plughandle->ext.callback = &afbHalCBs; + plughandle->ext.private_data = (void*) plughandle; + + + + err = snd_ctl_ext_create(&plughandle->ext, name, mode); + if (err < 0) { + SNDERR("Fail Register sndctl for devid=%s", plughandle->devid); + goto OnErrorExit; + } + + // Plugin register controls update handlep before exiting + *handlep = plughandle->ext.handle; + return 0; + +OnErrorExit: + free(plughandle); + return -1; +} + +SND_CTL_PLUGIN_SYMBOL(afbhal); diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt b/Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt new file mode 100644 index 0000000..93642b2 --- /dev/null +++ b/Alsa-Plugin/_Alsa-Hal-plugin/CMakeLists.txt @@ -0,0 +1,55 @@ +########################################################################### +# Copyright 2015, 2016, 2017 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. +########################################################################### + +# Activate ALSA dynamic build build mode get resolve "snd_dlsym_start" +add_compile_options(-DPIC) + +# Add target to project dependency list +PROJECT_TARGET_ADD(ctl_afbhal) + + # Define targets + ADD_LIBRARY(${TARGET_NAME} MODULE HalPlugCtl.c) + + # Alsa Plugin properties + SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES + PREFIX "libasound_module_" + OUTPUT_NAME ${TARGET_NAME} + ) + + # Library dependencies (include updates automatically) + TARGET_LINK_LIBRARIES(${TARGET_NAME} + ${link_libraries} + ) + install(TARGETS ${TARGET_NAME} LIBRARY DESTINATION lib/alsa-lib) + +PROJECT_TARGET_ADD(cb_sample) + + # Define targets + ADD_LIBRARY(${TARGET_NAME} MODULE HalPlugCb.c) + + # Alsa Plugin properties + SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES + PREFIX "afbhal_" + OUTPUT_NAME ${TARGET_NAME} + ) + + # Library dependencies (include updates automatically) + TARGET_LINK_LIBRARIES(${TARGET_NAME} + ${link_libraries} + ) + install(TARGETS ${TARGET_NAME} LIBRARY DESTINATION lib) diff --git a/Alsa-Plugin/_Alsa-Hal-plugin/README.md b/Alsa-Plugin/_Alsa-Hal-plugin/README.md new file mode 100644 index 0000000..1c1e7a2 --- /dev/null +++ b/Alsa-Plugin/_Alsa-Hal-plugin/README.md @@ -0,0 +1,44 @@ +Hal-Plugin + +Object: provide an ALSA a HAL (Hardware Abstraction Layer) to automotive sound cards +Status: Current version is proof of concept and not a usable product +Author: Fulup Ar Foll +Date : June-2017 + +HAL-plugin allows: + - to expose any existing NUMID under a customized label name, this is order to abstract sound card config. + - to add non alsa NUMID supported through a callback mechanism (eg: volume rampdown, power off, ...) + +installation + - Plugin should be placed where ever alsaplugins are located (typically: /usr/share/alsa-lib) + - Callback sharelib directory should be declare in $LD_LIBRARY_PATH + +Config +``` +cat ~/.asoundrc + ctl.agl_hal { + type afbhal + devid "hw:4" + cblib "afbhal_cb_sample.so" + ctls { + # ctlLabel {numid integer name "Alsa Ctl Name"} + MasterSwitch { numid 4 name "My_First_Control" } + MasterVol { numid 5 name "My_Second_Control" } + CB_sample { ctlcb @AfbHalSampleCB name "My_Sample_Callback"} + } + pcm.agl_hal { + type copy # Copy PCM + slave "hw:4" # Slave name + } +``` + +With such a config file + - numid=4 from sndcard=hw:4 is renamed "My_First_Control" + - numid=4 from sndcard=hw:4 is renamed "My_Second_Control" + - numid=4 will call AfbHalSampleCB from afbhal_cb_sample.so + +Note: to really implement a usable HAL at minimum every ALSA call should be implemented and read/write of values should be normalised from 0 to 100% with a step of 1. + +Conclusion: This demonstrate that implementing a HAL that both abstract ALSA get/set and enable non ALSA support is possible at an acceptable cost +without having to hack ALSA source code. The beauty of the model is than it is fully transparent to any ALSA application. The limit is that the plugin is loaded +within every application context, thus interaction with an external event loop remains complete as well as conflict management in case of share resources. |