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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  * Inspired by TinyHW, written by Mark Brown at Wolfson Micro
      4  *
      5  * Licensed under the Apache License, Version 2.0 (the "License");
      6  * you may not use this file except in compliance with the License.
      7  * You may obtain a copy of the License at
      8  *
      9  *      http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  * Unless required by applicable law or agreed to in writing, software
     12  * distributed under the License is distributed on an "AS IS" BASIS,
     13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  * See the License for the specific language governing permissions and
     15  * limitations under the License.
     16  */
     17 
     18 #define LOG_TAG "audio_route"
     19 /*#define LOG_NDEBUG 0*/
     20 
     21 #include <errno.h>
     22 #include <expat.h>
     23 #include <stdbool.h>
     24 #include <stdio.h>
     25 #include <string.h>
     26 
     27 #include <cutils/log.h>
     28 
     29 #include <tinyalsa/asoundlib.h>
     30 
     31 #define BUF_SIZE 1024
     32 #define MIXER_XML_PATH "/system/etc/mixer_paths.xml"
     33 #define INITIAL_MIXER_PATH_SIZE 8
     34 
     35 union ctl_values {
     36     int *enumerated;
     37     long *integer;
     38     void *ptr;
     39     unsigned char *bytes;
     40 };
     41 
     42 struct mixer_state {
     43     struct mixer_ctl *ctl;
     44     unsigned int num_values;
     45     union ctl_values old_value;
     46     union ctl_values new_value;
     47     union ctl_values reset_value;
     48 };
     49 
     50 struct mixer_setting {
     51     unsigned int ctl_index;
     52     unsigned int num_values;
     53     unsigned int type;
     54     union ctl_values value;
     55 };
     56 
     57 struct mixer_value {
     58     unsigned int ctl_index;
     59     int index;
     60     long value;
     61 };
     62 
     63 struct mixer_path {
     64     char *name;
     65     unsigned int size;
     66     unsigned int length;
     67     struct mixer_setting *setting;
     68 };
     69 
     70 struct audio_route {
     71     struct mixer *mixer;
     72     unsigned int num_mixer_ctls;
     73     struct mixer_state *mixer_state;
     74 
     75     unsigned int mixer_path_size;
     76     unsigned int num_mixer_paths;
     77     struct mixer_path *mixer_path;
     78 };
     79 
     80 struct config_parse_state {
     81     struct audio_route *ar;
     82     struct mixer_path *path;
     83     int level;
     84 };
     85 
     86 /* path functions */
     87 
     88 static bool is_supported_ctl_type(enum mixer_ctl_type type)
     89 {
     90     switch (type) {
     91     case MIXER_CTL_TYPE_BOOL:
     92     case MIXER_CTL_TYPE_INT:
     93     case MIXER_CTL_TYPE_ENUM:
     94     case MIXER_CTL_TYPE_BYTE:
     95         return true;
     96     default:
     97         return false;
     98     }
     99 }
    100 
    101 /* as they match in alsa */
    102 static size_t sizeof_ctl_type(enum mixer_ctl_type type) {
    103     switch (type) {
    104     case MIXER_CTL_TYPE_BOOL:
    105     case MIXER_CTL_TYPE_INT:
    106         return sizeof(long);
    107     case MIXER_CTL_TYPE_ENUM:
    108         return sizeof(int);
    109     case MIXER_CTL_TYPE_BYTE:
    110         return sizeof(unsigned char);
    111     case MIXER_CTL_TYPE_INT64:
    112     case MIXER_CTL_TYPE_IEC958:
    113     case MIXER_CTL_TYPE_UNKNOWN:
    114     default:
    115         LOG_ALWAYS_FATAL("Unsupported mixer ctl type: %d, check type before calling", (int)type);
    116         return 0;
    117     }
    118 }
    119 
    120 static inline struct mixer_ctl *index_to_ctl(struct audio_route *ar,
    121                                              unsigned int ctl_index)
    122 {
    123     return ar->mixer_state[ctl_index].ctl;
    124 }
    125 
    126 #if 0
    127 static void path_print(struct audio_route *ar, struct mixer_path *path)
    128 {
    129     unsigned int i;
    130     unsigned int j;
    131 
    132     ALOGE("Path: %s, length: %d", path->name, path->length);
    133     for (i = 0; i < path->length; i++) {
    134         struct mixer_ctl *ctl = index_to_ctl(ar, path->setting[i].ctl_index);
    135 
    136         ALOGE("  id=%d: ctl=%s", i, mixer_ctl_get_name(ctl));
    137         if (mixer_ctl_get_type(ctl) == MIXER_CTL_TYPE_BYTE) {
    138             for (j = 0; j < path->setting[i].num_values; j++)
    139                 ALOGE("    id=%d value=0x%02x", j, path->setting[i].value.bytes[j]);
    140         } else if (mixer_ctl_get_type(ctl) == MIXER_CTL_TYPE_ENUM) {
    141             for (j = 0; j < path->setting[i].num_values; j++)
    142                 ALOGE("    id=%d value=%d", j, path->setting[i].value.enumerated[j]);
    143         } else {
    144             for (j = 0; j < path->setting[i].num_values; j++)
    145                 ALOGE("    id=%d value=%ld", j, path->setting[i].value.integer[j]);
    146         }
    147     }
    148 }
    149 #endif
    150 
    151 static void path_free(struct audio_route *ar)
    152 {
    153     unsigned int i;
    154 
    155     for (i = 0; i < ar->num_mixer_paths; i++) {
    156         if (ar->mixer_path[i].name)
    157             free(ar->mixer_path[i].name);
    158         if (ar->mixer_path[i].setting) {
    159             if (ar->mixer_path[i].setting->value.ptr)
    160                 free(ar->mixer_path[i].setting->value.ptr);
    161             free(ar->mixer_path[i].setting);
    162         }
    163     }
    164     free(ar->mixer_path);
    165     ar->mixer_path = NULL;
    166     ar->mixer_path_size = 0;
    167 }
    168 
    169 static struct mixer_path *path_get_by_name(struct audio_route *ar,
    170                                            const char *name)
    171 {
    172     unsigned int i;
    173 
    174     for (i = 0; i < ar->num_mixer_paths; i++)
    175         if (strcmp(ar->mixer_path[i].name, name) == 0)
    176             return &ar->mixer_path[i];
    177 
    178     return NULL;
    179 }
    180 
    181 static struct mixer_path *path_create(struct audio_route *ar, const char *name)
    182 {
    183     struct mixer_path *new_mixer_path = NULL;
    184 
    185     if (path_get_by_name(ar, name)) {
    186         ALOGE("Path name '%s' already exists", name);
    187         return NULL;
    188     }
    189 
    190     /* check if we need to allocate more space for mixer paths */
    191     if (ar->mixer_path_size <= ar->num_mixer_paths) {
    192         if (ar->mixer_path_size == 0)
    193             ar->mixer_path_size = INITIAL_MIXER_PATH_SIZE;
    194         else
    195             ar->mixer_path_size *= 2;
    196 
    197         new_mixer_path = realloc(ar->mixer_path, ar->mixer_path_size *
    198                                  sizeof(struct mixer_path));
    199         if (new_mixer_path == NULL) {
    200             ALOGE("Unable to allocate more paths");
    201             return NULL;
    202         } else {
    203             ar->mixer_path = new_mixer_path;
    204         }
    205     }
    206 
    207     /* initialise the new mixer path */
    208     ar->mixer_path[ar->num_mixer_paths].name = strdup(name);
    209     ar->mixer_path[ar->num_mixer_paths].size = 0;
    210     ar->mixer_path[ar->num_mixer_paths].length = 0;
    211     ar->mixer_path[ar->num_mixer_paths].setting = NULL;
    212 
    213     /* return the mixer path just added, then increment number of them */
    214     return &ar->mixer_path[ar->num_mixer_paths++];
    215 }
    216 
    217 static int find_ctl_index_in_path(struct mixer_path *path,
    218                                   unsigned int ctl_index)
    219 {
    220     unsigned int i;
    221 
    222     for (i = 0; i < path->length; i++)
    223         if (path->setting[i].ctl_index == ctl_index)
    224             return i;
    225 
    226     return -1;
    227 }
    228 
    229 static int alloc_path_setting(struct mixer_path *path)
    230 {
    231     struct mixer_setting *new_path_setting;
    232     int path_index;
    233 
    234     /* check if we need to allocate more space for path settings */
    235     if (path->size <= path->length) {
    236         if (path->size == 0)
    237             path->size = INITIAL_MIXER_PATH_SIZE;
    238         else
    239             path->size *= 2;
    240 
    241         new_path_setting = realloc(path->setting,
    242                                    path->size * sizeof(struct mixer_setting));
    243         if (new_path_setting == NULL) {
    244             ALOGE("Unable to allocate more path settings");
    245             return -1;
    246         } else {
    247             path->setting = new_path_setting;
    248         }
    249     }
    250 
    251     path_index = path->length;
    252     path->length++;
    253 
    254     return path_index;
    255 }
    256 
    257 static int path_add_setting(struct audio_route *ar, struct mixer_path *path,
    258                             struct mixer_setting *setting)
    259 {
    260     int path_index;
    261 
    262     if (find_ctl_index_in_path(path, setting->ctl_index) != -1) {
    263         struct mixer_ctl *ctl = index_to_ctl(ar, setting->ctl_index);
    264 
    265         ALOGE("Control '%s' already exists in path '%s'",
    266               mixer_ctl_get_name(ctl), path->name);
    267         return -1;
    268     }
    269 
    270     if (!is_supported_ctl_type(setting->type)) {
    271         ALOGE("unsupported type %d", (int)setting->type);
    272         return -1;
    273     }
    274 
    275     path_index = alloc_path_setting(path);
    276     if (path_index < 0)
    277         return -1;
    278 
    279     path->setting[path_index].ctl_index = setting->ctl_index;
    280     path->setting[path_index].type = setting->type;
    281     path->setting[path_index].num_values = setting->num_values;
    282 
    283     size_t value_sz = sizeof_ctl_type(setting->type);
    284 
    285     path->setting[path_index].value.ptr = calloc(setting->num_values, value_sz);
    286     /* copy all values */
    287     memcpy(path->setting[path_index].value.ptr, setting->value.ptr,
    288            setting->num_values * value_sz);
    289 
    290     return 0;
    291 }
    292 
    293 static int path_add_value(struct audio_route *ar, struct mixer_path *path,
    294                           struct mixer_value *mixer_value)
    295 {
    296     unsigned int i;
    297     int path_index;
    298     unsigned int num_values;
    299     struct mixer_ctl *ctl;
    300 
    301     /* Check that mixer value index is within range */
    302     ctl = index_to_ctl(ar, mixer_value->ctl_index);
    303     num_values = mixer_ctl_get_num_values(ctl);
    304     if (mixer_value->index >= (int)num_values) {
    305         ALOGE("mixer index %d is out of range for '%s'", mixer_value->index,
    306               mixer_ctl_get_name(ctl));
    307         return -1;
    308     }
    309 
    310     path_index = find_ctl_index_in_path(path, mixer_value->ctl_index);
    311     if (path_index < 0) {
    312         /* New path */
    313 
    314         enum mixer_ctl_type type = mixer_ctl_get_type(ctl);
    315         if (!is_supported_ctl_type(type)) {
    316             ALOGE("unsupported type %d", (int)type);
    317             return -1;
    318         }
    319         path_index = alloc_path_setting(path);
    320         if (path_index < 0)
    321             return -1;
    322 
    323         /* initialise the new path setting */
    324         path->setting[path_index].ctl_index = mixer_value->ctl_index;
    325         path->setting[path_index].num_values = num_values;
    326         path->setting[path_index].type = type;
    327 
    328         size_t value_sz = sizeof_ctl_type(type);
    329         path->setting[path_index].value.ptr = calloc(num_values, value_sz);
    330         if (path->setting[path_index].type == MIXER_CTL_TYPE_BYTE)
    331             path->setting[path_index].value.bytes[0] = mixer_value->value;
    332         else if (path->setting[path_index].type == MIXER_CTL_TYPE_ENUM)
    333             path->setting[path_index].value.enumerated[0] = mixer_value->value;
    334         else
    335             path->setting[path_index].value.integer[0] = mixer_value->value;
    336     }
    337 
    338     if (mixer_value->index == -1) {
    339         /* set all values the same */
    340         if (path->setting[path_index].type == MIXER_CTL_TYPE_BYTE) {
    341             for (i = 0; i < num_values; i++)
    342                 path->setting[path_index].value.bytes[i] = mixer_value->value;
    343         } else if (path->setting[path_index].type == MIXER_CTL_TYPE_ENUM) {
    344             for (i = 0; i < num_values; i++)
    345                 path->setting[path_index].value.enumerated[i] = mixer_value->value;
    346         } else {
    347             for (i = 0; i < num_values; i++)
    348                 path->setting[path_index].value.integer[i] = mixer_value->value;
    349         }
    350     } else {
    351         /* set only one value */
    352         if (path->setting[path_index].type == MIXER_CTL_TYPE_BYTE)
    353             path->setting[path_index].value.bytes[mixer_value->index] = mixer_value->value;
    354         else if (path->setting[path_index].type == MIXER_CTL_TYPE_ENUM)
    355             path->setting[path_index].value.enumerated[mixer_value->index] = mixer_value->value;
    356         else
    357             path->setting[path_index].value.integer[mixer_value->index] = mixer_value->value;
    358     }
    359 
    360     return 0;
    361 }
    362 
    363 static int path_add_path(struct audio_route *ar, struct mixer_path *path,
    364                          struct mixer_path *sub_path)
    365 {
    366     unsigned int i;
    367 
    368     for (i = 0; i < sub_path->length; i++)
    369         if (path_add_setting(ar, path, &sub_path->setting[i]) < 0)
    370             return -1;
    371 
    372     return 0;
    373 }
    374 
    375 static int path_apply(struct audio_route *ar, struct mixer_path *path)
    376 {
    377     unsigned int i;
    378     unsigned int ctl_index;
    379     struct mixer_ctl *ctl;
    380     enum mixer_ctl_type type;
    381 
    382     for (i = 0; i < path->length; i++) {
    383         ctl_index = path->setting[i].ctl_index;
    384         ctl = index_to_ctl(ar, ctl_index);
    385         type = mixer_ctl_get_type(ctl);
    386         if (!is_supported_ctl_type(type))
    387             continue;
    388         size_t value_sz = sizeof_ctl_type(type);
    389         memcpy(ar->mixer_state[ctl_index].new_value.ptr, path->setting[i].value.ptr,
    390                    path->setting[i].num_values * value_sz);
    391     }
    392 
    393     return 0;
    394 }
    395 
    396 static int path_reset(struct audio_route *ar, struct mixer_path *path)
    397 {
    398     unsigned int i;
    399     unsigned int ctl_index;
    400     struct mixer_ctl *ctl;
    401     enum mixer_ctl_type type;
    402 
    403     for (i = 0; i < path->length; i++) {
    404         ctl_index = path->setting[i].ctl_index;
    405         ctl = index_to_ctl(ar, ctl_index);
    406         type = mixer_ctl_get_type(ctl);
    407         if (!is_supported_ctl_type(type))
    408             continue;
    409         size_t value_sz = sizeof_ctl_type(type);
    410         /* reset the value(s) */
    411         memcpy(ar->mixer_state[ctl_index].new_value.ptr,
    412                ar->mixer_state[ctl_index].reset_value.ptr,
    413                ar->mixer_state[ctl_index].num_values * value_sz);
    414     }
    415 
    416     return 0;
    417 }
    418 
    419 /* mixer helper function */
    420 static int mixer_enum_string_to_value(struct mixer_ctl *ctl, const char *string)
    421 {
    422     unsigned int i;
    423 
    424     /* Search the enum strings for a particular one */
    425     for (i = 0; i < mixer_ctl_get_num_enums(ctl); i++) {
    426         if (strcmp(mixer_ctl_get_enum_string(ctl, i), string) == 0)
    427             break;
    428     }
    429 
    430     return i;
    431 }
    432 
    433 static void start_tag(void *data, const XML_Char *tag_name,
    434                       const XML_Char **attr)
    435 {
    436     const XML_Char *attr_name = NULL;
    437     const XML_Char *attr_id = NULL;
    438     const XML_Char *attr_value = NULL;
    439     struct config_parse_state *state = data;
    440     struct audio_route *ar = state->ar;
    441     unsigned int i;
    442     unsigned int ctl_index;
    443     struct mixer_ctl *ctl;
    444     long value;
    445     unsigned int id;
    446     struct mixer_value mixer_value;
    447     enum mixer_ctl_type type;
    448 
    449     /* Get name, id and value attributes (these may be empty) */
    450     for (i = 0; attr[i]; i += 2) {
    451         if (strcmp(attr[i], "name") == 0)
    452             attr_name = attr[i + 1];
    453         if (strcmp(attr[i], "id") == 0)
    454             attr_id = attr[i + 1];
    455         else if (strcmp(attr[i], "value") == 0)
    456             attr_value = attr[i + 1];
    457     }
    458 
    459     /* Look at tags */
    460     if (strcmp(tag_name, "path") == 0) {
    461         if (attr_name == NULL) {
    462             ALOGE("Unnamed path!");
    463         } else {
    464             if (state->level == 1) {
    465                 /* top level path: create and stash the path */
    466                 state->path = path_create(ar, (char *)attr_name);
    467             } else {
    468                 /* nested path */
    469                 struct mixer_path *sub_path = path_get_by_name(ar, attr_name);
    470                 path_add_path(ar, state->path, sub_path);
    471             }
    472         }
    473     }
    474 
    475     else if (strcmp(tag_name, "ctl") == 0) {
    476         /* Obtain the mixer ctl and value */
    477         ctl = mixer_get_ctl_by_name(ar->mixer, attr_name);
    478         if (ctl == NULL) {
    479             ALOGE("Control '%s' doesn't exist - skipping", attr_name);
    480             goto done;
    481         }
    482 
    483         switch (mixer_ctl_get_type(ctl)) {
    484         case MIXER_CTL_TYPE_BOOL:
    485         case MIXER_CTL_TYPE_INT:
    486             value = strtol((char *)attr_value, NULL, 0);
    487             break;
    488         case MIXER_CTL_TYPE_BYTE:
    489             value = (unsigned char) strtol((char *)attr_value, NULL, 16);
    490             break;
    491         case MIXER_CTL_TYPE_ENUM:
    492             value = mixer_enum_string_to_value(ctl, (char *)attr_value);
    493             break;
    494         default:
    495             value = 0;
    496             break;
    497         }
    498 
    499         /* locate the mixer ctl in the list */
    500         for (ctl_index = 0; ctl_index < ar->num_mixer_ctls; ctl_index++) {
    501             if (ar->mixer_state[ctl_index].ctl == ctl)
    502                 break;
    503         }
    504 
    505         if (state->level == 1) {
    506             /* top level ctl (initial setting) */
    507 
    508             type = mixer_ctl_get_type(ctl);
    509             if (is_supported_ctl_type(type)) {
    510                 /* apply the new value */
    511                 if (attr_id) {
    512                     /* set only one value */
    513                     id = atoi((char *)attr_id);
    514                     if (id < ar->mixer_state[ctl_index].num_values)
    515                         if (type == MIXER_CTL_TYPE_BYTE)
    516                             ar->mixer_state[ctl_index].new_value.bytes[id] = value;
    517                         else if (type == MIXER_CTL_TYPE_ENUM)
    518                             ar->mixer_state[ctl_index].new_value.enumerated[id] = value;
    519                         else
    520                             ar->mixer_state[ctl_index].new_value.integer[id] = value;
    521                     else
    522                         ALOGE("value id out of range for mixer ctl '%s'",
    523                               mixer_ctl_get_name(ctl));
    524                 } else {
    525                     /* set all values the same */
    526                     for (i = 0; i < ar->mixer_state[ctl_index].num_values; i++)
    527                         if (type == MIXER_CTL_TYPE_BYTE)
    528                             ar->mixer_state[ctl_index].new_value.bytes[i] = value;
    529                         else if (type == MIXER_CTL_TYPE_ENUM)
    530                             ar->mixer_state[ctl_index].new_value.enumerated[i] = value;
    531                         else
    532                             ar->mixer_state[ctl_index].new_value.integer[i] = value;
    533                 }
    534             }
    535         } else {
    536             /* nested ctl (within a path) */
    537             mixer_value.ctl_index = ctl_index;
    538             mixer_value.value = value;
    539             if (attr_id)
    540                 mixer_value.index = atoi((char *)attr_id);
    541             else
    542                 mixer_value.index = -1;
    543             path_add_value(ar, state->path, &mixer_value);
    544         }
    545     }
    546 
    547 done:
    548     state->level++;
    549 }
    550 
    551 static void end_tag(void *data, const XML_Char *tag_name)
    552 {
    553     struct config_parse_state *state = data;
    554     (void)tag_name;
    555 
    556     state->level--;
    557 }
    558 
    559 static int alloc_mixer_state(struct audio_route *ar)
    560 {
    561     unsigned int i;
    562     unsigned int num_values;
    563     struct mixer_ctl *ctl;
    564     enum mixer_ctl_type type;
    565 
    566     ar->num_mixer_ctls = mixer_get_num_ctls(ar->mixer);
    567     ar->mixer_state = calloc(ar->num_mixer_ctls, sizeof(struct mixer_state));
    568     if (!ar->mixer_state)
    569         return -1;
    570 
    571     for (i = 0; i < ar->num_mixer_ctls; i++) {
    572         ctl = mixer_get_ctl(ar->mixer, i);
    573         num_values = mixer_ctl_get_num_values(ctl);
    574 
    575         ar->mixer_state[i].ctl = ctl;
    576         ar->mixer_state[i].num_values = num_values;
    577 
    578         /* Skip unsupported types that are not supported yet in XML */
    579         type = mixer_ctl_get_type(ctl);
    580 
    581         if (!is_supported_ctl_type(type))
    582             continue;
    583 
    584         size_t value_sz = sizeof_ctl_type(type);
    585         ar->mixer_state[i].old_value.ptr = calloc(num_values, value_sz);
    586         ar->mixer_state[i].new_value.ptr = calloc(num_values, value_sz);
    587         ar->mixer_state[i].reset_value.ptr = calloc(num_values, value_sz);
    588 
    589         if (type == MIXER_CTL_TYPE_ENUM)
    590             ar->mixer_state[i].old_value.enumerated[0] = mixer_ctl_get_value(ctl, 0);
    591         else
    592             mixer_ctl_get_array(ctl, ar->mixer_state[i].old_value.ptr, num_values);
    593 
    594         memcpy(ar->mixer_state[i].new_value.ptr, ar->mixer_state[i].old_value.ptr,
    595                num_values * value_sz);
    596     }
    597 
    598     return 0;
    599 }
    600 
    601 static void free_mixer_state(struct audio_route *ar)
    602 {
    603     unsigned int i;
    604     enum mixer_ctl_type type;
    605 
    606     for (i = 0; i < ar->num_mixer_ctls; i++) {
    607         type = mixer_ctl_get_type(ar->mixer_state[i].ctl);
    608         if (!is_supported_ctl_type(type))
    609             continue;
    610 
    611         free(ar->mixer_state[i].old_value.ptr);
    612         free(ar->mixer_state[i].new_value.ptr);
    613         free(ar->mixer_state[i].reset_value.ptr);
    614     }
    615 
    616     free(ar->mixer_state);
    617     ar->mixer_state = NULL;
    618 }
    619 
    620 /* Update the mixer with any changed values */
    621 int audio_route_update_mixer(struct audio_route *ar)
    622 {
    623     unsigned int i;
    624     unsigned int j;
    625     struct mixer_ctl *ctl;
    626 
    627     for (i = 0; i < ar->num_mixer_ctls; i++) {
    628         unsigned int num_values = ar->mixer_state[i].num_values;
    629         enum mixer_ctl_type type;
    630 
    631         ctl = ar->mixer_state[i].ctl;
    632 
    633         /* Skip unsupported types */
    634         type = mixer_ctl_get_type(ctl);
    635         if (!is_supported_ctl_type(type))
    636             continue;
    637 
    638         /* if the value has changed, update the mixer */
    639         bool changed = false;
    640         if (type == MIXER_CTL_TYPE_BYTE) {
    641             for (j = 0; j < num_values; j++) {
    642                 if (ar->mixer_state[i].old_value.bytes[j] != ar->mixer_state[i].new_value.bytes[j]) {
    643                     changed = true;
    644                     break;
    645                 }
    646             }
    647          } else if (type == MIXER_CTL_TYPE_ENUM) {
    648              for (j = 0; j < num_values; j++) {
    649                  if (ar->mixer_state[i].old_value.enumerated[j]
    650                          != ar->mixer_state[i].new_value.enumerated[j]) {
    651                      changed = true;
    652                      break;
    653                  }
    654              }
    655          } else {
    656             for (j = 0; j < num_values; j++) {
    657                 if (ar->mixer_state[i].old_value.integer[j] != ar->mixer_state[i].new_value.integer[j]) {
    658                     changed = true;
    659                     break;
    660                 }
    661             }
    662         }
    663         if (changed) {
    664             if (type == MIXER_CTL_TYPE_ENUM)
    665                 mixer_ctl_set_value(ctl, 0, ar->mixer_state[i].new_value.enumerated[0]);
    666             else
    667                 mixer_ctl_set_array(ctl, ar->mixer_state[i].new_value.ptr, num_values);
    668 
    669             size_t value_sz = sizeof_ctl_type(type);
    670             memcpy(ar->mixer_state[i].old_value.ptr, ar->mixer_state[i].new_value.ptr,
    671                    num_values * value_sz);
    672         }
    673     }
    674 
    675     return 0;
    676 }
    677 
    678 /* saves the current state of the mixer, for resetting all controls */
    679 static void save_mixer_state(struct audio_route *ar)
    680 {
    681     unsigned int i;
    682     enum mixer_ctl_type type;
    683 
    684     for (i = 0; i < ar->num_mixer_ctls; i++) {
    685         type = mixer_ctl_get_type(ar->mixer_state[i].ctl);
    686         if (!is_supported_ctl_type(type))
    687             continue;
    688 
    689         size_t value_sz = sizeof_ctl_type(type);
    690         memcpy(ar->mixer_state[i].reset_value.ptr, ar->mixer_state[i].new_value.ptr,
    691                ar->mixer_state[i].num_values * value_sz);
    692     }
    693 }
    694 
    695 /* Reset the audio routes back to the initial state */
    696 void audio_route_reset(struct audio_route *ar)
    697 {
    698     unsigned int i;
    699     enum mixer_ctl_type type;
    700 
    701     /* load all of the saved values */
    702     for (i = 0; i < ar->num_mixer_ctls; i++) {
    703         type = mixer_ctl_get_type(ar->mixer_state[i].ctl);
    704         if (!is_supported_ctl_type(type))
    705             continue;
    706 
    707         size_t value_sz = sizeof_ctl_type(type);
    708         memcpy(ar->mixer_state[i].new_value.ptr, ar->mixer_state[i].reset_value.ptr,
    709             ar->mixer_state[i].num_values * value_sz);
    710     }
    711 }
    712 
    713 /* Apply an audio route path by name */
    714 int audio_route_apply_path(struct audio_route *ar, const char *name)
    715 {
    716     struct mixer_path *path;
    717 
    718     if (!ar) {
    719         ALOGE("invalid audio_route");
    720         return -1;
    721     }
    722 
    723     path = path_get_by_name(ar, name);
    724     if (!path) {
    725         ALOGE("unable to find path '%s'", name);
    726         return -1;
    727     }
    728 
    729     path_apply(ar, path);
    730 
    731     return 0;
    732 }
    733 
    734 /* Reset an audio route path by name */
    735 int audio_route_reset_path(struct audio_route *ar, const char *name)
    736 {
    737     struct mixer_path *path;
    738 
    739     if (!ar) {
    740         ALOGE("invalid audio_route");
    741         return -1;
    742     }
    743 
    744     path = path_get_by_name(ar, name);
    745     if (!path) {
    746         ALOGE("unable to find path '%s'", name);
    747         return -1;
    748     }
    749 
    750     path_reset(ar, path);
    751 
    752     return 0;
    753 }
    754 
    755 /*
    756  * Operates on the specified path .. controls will be updated in the
    757  * order listed in the XML file
    758  */
    759 static int audio_route_update_path(struct audio_route *ar, const char *name, bool reverse)
    760 {
    761     struct mixer_path *path;
    762     int32_t i, end;
    763     unsigned int j;
    764 
    765     if (!ar) {
    766         ALOGE("invalid audio_route");
    767         return -1;
    768     }
    769 
    770     path = path_get_by_name(ar, name);
    771     if (!path) {
    772         ALOGE("unable to find path '%s'", name);
    773         return -1;
    774     }
    775 
    776     i = reverse ? (path->length - 1) : 0;
    777     end = reverse ? -1 : (int32_t)path->length;
    778 
    779     while (i != end) {
    780         unsigned int ctl_index;
    781         enum mixer_ctl_type type;
    782 
    783         ctl_index = path->setting[i].ctl_index;
    784 
    785         struct mixer_state * ms = &ar->mixer_state[ctl_index];
    786 
    787         type = mixer_ctl_get_type(ms->ctl);
    788         if (!is_supported_ctl_type(type)) {
    789             continue;
    790         }
    791 
    792        size_t value_sz = sizeof_ctl_type(type);
    793         /* if any value has changed, update the mixer */
    794         for (j = 0; j < ms->num_values; j++) {
    795             if (type == MIXER_CTL_TYPE_BYTE) {
    796                 if (ms->old_value.bytes[j] != ms->new_value.bytes[j]) {
    797                     mixer_ctl_set_array(ms->ctl, ms->new_value.bytes, ms->num_values);
    798                     memcpy(ms->old_value.bytes, ms->new_value.bytes, ms->num_values * value_sz);
    799                     break;
    800                 }
    801             } else if (type == MIXER_CTL_TYPE_ENUM) {
    802                 if (ms->old_value.enumerated[j] != ms->new_value.enumerated[j]) {
    803                     mixer_ctl_set_value(ms->ctl, 0, ms->new_value.enumerated[0]);
    804                     memcpy(ms->old_value.enumerated, ms->new_value.enumerated,
    805                             ms->num_values * value_sz);
    806                     break;
    807                 }
    808             } else if (ms->old_value.integer[j] != ms->new_value.integer[j]) {
    809                 mixer_ctl_set_array(ms->ctl, ms->new_value.integer, ms->num_values);
    810                 memcpy(ms->old_value.integer, ms->new_value.integer, ms->num_values * value_sz);
    811                 break;
    812             }
    813         }
    814 
    815         i = reverse ? (i - 1) : (i + 1);
    816     }
    817     return 0;
    818 }
    819 
    820 int audio_route_apply_and_update_path(struct audio_route *ar, const char *name)
    821 {
    822     if (audio_route_apply_path(ar, name) < 0) {
    823         return -1;
    824     }
    825     return audio_route_update_path(ar, name, false /*reverse*/);
    826 }
    827 
    828 int audio_route_reset_and_update_path(struct audio_route *ar, const char *name)
    829 {
    830     if (audio_route_reset_path(ar, name) < 0) {
    831         return -1;
    832     }
    833     return audio_route_update_path(ar, name, true /*reverse*/);
    834 }
    835 
    836 struct audio_route *audio_route_init(unsigned int card, const char *xml_path)
    837 {
    838     struct config_parse_state state;
    839     XML_Parser parser;
    840     FILE *file;
    841     int bytes_read;
    842     void *buf;
    843     struct audio_route *ar;
    844 
    845     ar = calloc(1, sizeof(struct audio_route));
    846     if (!ar)
    847         goto err_calloc;
    848 
    849     ar->mixer = mixer_open(card);
    850     if (!ar->mixer) {
    851         ALOGE("Unable to open the mixer, aborting.");
    852         goto err_mixer_open;
    853     }
    854 
    855     ar->mixer_path = NULL;
    856     ar->mixer_path_size = 0;
    857     ar->num_mixer_paths = 0;
    858 
    859     /* allocate space for and read current mixer settings */
    860     if (alloc_mixer_state(ar) < 0)
    861         goto err_mixer_state;
    862 
    863     /* use the default XML path if none is provided */
    864     if (xml_path == NULL)
    865         xml_path = MIXER_XML_PATH;
    866 
    867     file = fopen(xml_path, "r");
    868 
    869     if (!file) {
    870         ALOGE("Failed to open %s", xml_path);
    871         goto err_fopen;
    872     }
    873 
    874     parser = XML_ParserCreate(NULL);
    875     if (!parser) {
    876         ALOGE("Failed to create XML parser");
    877         goto err_parser_create;
    878     }
    879 
    880     memset(&state, 0, sizeof(state));
    881     state.ar = ar;
    882     XML_SetUserData(parser, &state);
    883     XML_SetElementHandler(parser, start_tag, end_tag);
    884 
    885     for (;;) {
    886         buf = XML_GetBuffer(parser, BUF_SIZE);
    887         if (buf == NULL)
    888             goto err_parse;
    889 
    890         bytes_read = fread(buf, 1, BUF_SIZE, file);
    891         if (bytes_read < 0)
    892             goto err_parse;
    893 
    894         if (XML_ParseBuffer(parser, bytes_read,
    895                             bytes_read == 0) == XML_STATUS_ERROR) {
    896             ALOGE("Error in mixer xml (%s)", MIXER_XML_PATH);
    897             goto err_parse;
    898         }
    899 
    900         if (bytes_read == 0)
    901             break;
    902     }
    903 
    904     /* apply the initial mixer values, and save them so we can reset the
    905        mixer to the original values */
    906     audio_route_update_mixer(ar);
    907     save_mixer_state(ar);
    908 
    909     XML_ParserFree(parser);
    910     fclose(file);
    911     return ar;
    912 
    913 err_parse:
    914     path_free(ar);
    915     XML_ParserFree(parser);
    916 err_parser_create:
    917     fclose(file);
    918 err_fopen:
    919     free_mixer_state(ar);
    920 err_mixer_state:
    921     mixer_close(ar->mixer);
    922 err_mixer_open:
    923     free(ar);
    924     ar = NULL;
    925 err_calloc:
    926     return NULL;
    927 }
    928 
    929 void audio_route_free(struct audio_route *ar)
    930 {
    931     free_mixer_state(ar);
    932     mixer_close(ar->mixer);
    933     path_free(ar);
    934     free(ar);
    935 }
    936