Initial Working Version on Alsa Policy-Policy-Hook

1 files changed, 423 insertions, 0 deletions

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);