1 /* mixer.h 2 ** 3 ** Copyright 2011, The Android Open Source Project 4 ** 5 ** Redistribution and use in source and binary forms, with or without 6 ** modification, are permitted provided that the following conditions are met: 7 ** * Redistributions of source code must retain the above copyright 8 ** notice, this list of conditions and the following disclaimer. 9 ** * Redistributions in binary form must reproduce the above copyright 10 ** notice, this list of conditions and the following disclaimer in the 11 ** documentation and/or other materials provided with the distribution. 12 ** * Neither the name of The Android Open Source Project nor the names of 13 ** its contributors may be used to endorse or promote products derived 14 ** from this software without specific prior written permission. 15 ** 16 ** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND 17 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 ** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE 20 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 ** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23 ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 26 ** DAMAGE. 27 */ 28 29 /** @file */ 30 31 /** @defgroup libtinyalsa-mixer Mixer Interface 32 * @brief All macros, structures and functions that make up the mixer interface. 33 */ 34 35 #ifndef TINYALSA_MIXER_H 36 #define TINYALSA_MIXER_H 37 38 #include <sys/time.h> 39 #include <stddef.h> 40 41 #if defined(__cplusplus) 42 extern "C" { 43 #endif 44 45 struct mixer; 46 47 struct mixer_ctl; 48 49 // mixer_ctl_event is a mirroring structure of snd_ctl_event 50 struct mixer_ctl_event { 51 int type; 52 union { 53 struct { 54 unsigned int mask; 55 struct { 56 unsigned int numid; 57 int iface; 58 unsigned int device; 59 unsigned int subdevice; 60 unsigned char name[44]; 61 unsigned int index; 62 } id; 63 } element; 64 unsigned char data[60]; 65 } data; 66 }; 67 68 /** Mixer control type. 69 * @ingroup libtinyalsa-mixer 70 */ 71 enum mixer_ctl_type { 72 /** boolean control type */ 73 MIXER_CTL_TYPE_BOOL, 74 /** integer control type */ 75 MIXER_CTL_TYPE_INT, 76 /** an enumerated control type */ 77 MIXER_CTL_TYPE_ENUM, 78 MIXER_CTL_TYPE_BYTE, 79 MIXER_CTL_TYPE_IEC958, 80 /** a 64 bit integer control type */ 81 MIXER_CTL_TYPE_INT64, 82 /** unknown control type */ 83 MIXER_CTL_TYPE_UNKNOWN, 84 /** end of the enumeration (not a control type) */ 85 MIXER_CTL_TYPE_MAX, 86 }; 87 88 struct mixer *mixer_open(unsigned int card); 89 90 void mixer_close(struct mixer *mixer); 91 92 int mixer_add_new_ctls(struct mixer *mixer); 93 94 const char *mixer_get_name(const struct mixer *mixer); 95 96 unsigned int mixer_get_num_ctls(const struct mixer *mixer); 97 98 unsigned int mixer_get_num_ctls_by_name(const struct mixer *mixer, const char *name); 99 100 const struct mixer_ctl *mixer_get_ctl_const(const struct mixer *mixer, unsigned int id); 101 102 struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id); 103 104 struct mixer_ctl *mixer_get_ctl_by_name(struct mixer *mixer, const char *name); 105 106 struct mixer_ctl *mixer_get_ctl_by_name_and_index(struct mixer *mixer, 107 const char *name, 108 unsigned int index); 109 110 int mixer_subscribe_events(struct mixer *mixer, int subscribe); 111 112 int mixer_wait_event(struct mixer *mixer, int timeout); 113 114 unsigned int mixer_ctl_get_id(const struct mixer_ctl *ctl); 115 116 const char *mixer_ctl_get_name(const struct mixer_ctl *ctl); 117 118 enum mixer_ctl_type mixer_ctl_get_type(const struct mixer_ctl *ctl); 119 120 const char *mixer_ctl_get_type_string(const struct mixer_ctl *ctl); 121 122 unsigned int mixer_ctl_get_num_values(const struct mixer_ctl *ctl); 123 124 unsigned int mixer_ctl_get_num_enums(const struct mixer_ctl *ctl); 125 126 const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, unsigned int enum_id); 127 128 /* Some sound cards update their controls due to external events, 129 * such as HDMI EDID byte data changing when an HDMI cable is 130 * connected. This API allows the count of elements to be updated. 131 */ 132 void mixer_ctl_update(struct mixer_ctl *ctl); 133 134 int mixer_ctl_is_access_tlv_rw(const struct mixer_ctl *ctl); 135 136 /* Set and get mixer controls */ 137 int mixer_ctl_get_percent(const struct mixer_ctl *ctl, unsigned int id); 138 139 int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent); 140 141 int mixer_ctl_get_value(const struct mixer_ctl *ctl, unsigned int id); 142 143 int mixer_ctl_get_array(const struct mixer_ctl *ctl, void *array, size_t count); 144 145 int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value); 146 147 int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count); 148 149 int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string); 150 151 /* Determine range of integer mixer controls */ 152 int mixer_ctl_get_range_min(const struct mixer_ctl *ctl); 153 154 int mixer_ctl_get_range_max(const struct mixer_ctl *ctl); 155 156 int mixer_read_event(struct mixer *mixer, struct mixer_ctl_event *event); 157 158 int mixer_consume_event(struct mixer *mixer); 159 #if defined(__cplusplus) 160 } /* extern "C" */ 161 #endif 162 163 #endif 164 165