1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 18 #ifndef ANDROID_AUDIO_HAL_INTERFACE_H 19 #define ANDROID_AUDIO_HAL_INTERFACE_H 20 21 #include <stdint.h> 22 #include <strings.h> 23 #include <sys/cdefs.h> 24 #include <sys/types.h> 25 26 #include <cutils/bitops.h> 27 28 #include <hardware/hardware.h> 29 #include <system/audio.h> 30 #include <hardware/audio_effect.h> 31 32 __BEGIN_DECLS 33 34 /** 35 * The id of this module 36 */ 37 #define AUDIO_HARDWARE_MODULE_ID "audio" 38 39 /** 40 * Name of the audio devices to open 41 */ 42 #define AUDIO_HARDWARE_INTERFACE "audio_hw_if" 43 44 /**************************************/ 45 46 /** 47 * standard audio parameters that the HAL may need to handle 48 */ 49 50 /** 51 * audio device parameters 52 */ 53 54 /* BT SCO Noise Reduction + Echo Cancellation parameters */ 55 #define AUDIO_PARAMETER_KEY_BT_NREC "bt_headset_nrec" 56 #define AUDIO_PARAMETER_VALUE_ON "on" 57 #define AUDIO_PARAMETER_VALUE_OFF "off" 58 59 /* TTY mode selection */ 60 #define AUDIO_PARAMETER_KEY_TTY_MODE "tty_mode" 61 #define AUDIO_PARAMETER_VALUE_TTY_OFF "tty_off" 62 #define AUDIO_PARAMETER_VALUE_TTY_VCO "tty_vco" 63 #define AUDIO_PARAMETER_VALUE_TTY_HCO "tty_hco" 64 #define AUDIO_PARAMETER_VALUE_TTY_FULL "tty_full" 65 66 /** 67 * audio stream parameters 68 */ 69 70 #define AUDIO_PARAMETER_STREAM_ROUTING "routing" 71 #define AUDIO_PARAMETER_STREAM_FORMAT "format" 72 #define AUDIO_PARAMETER_STREAM_CHANNELS "channels" 73 #define AUDIO_PARAMETER_STREAM_FRAME_COUNT "frame_count" 74 #define AUDIO_PARAMETER_STREAM_INPUT_SOURCE "input_source" 75 76 /**************************************/ 77 78 /* common audio stream parameters and operations */ 79 struct audio_stream { 80 81 /** 82 * sampling rate is in Hz - eg. 44100 83 */ 84 uint32_t (*get_sample_rate)(const struct audio_stream *stream); 85 86 /* currently unused - use set_parameters with key 87 * AUDIO_PARAMETER_STREAM_SAMPLING_RATE 88 */ 89 int (*set_sample_rate)(struct audio_stream *stream, uint32_t rate); 90 91 /** 92 * size of output buffer in bytes - eg. 4800 93 */ 94 size_t (*get_buffer_size)(const struct audio_stream *stream); 95 96 /** 97 * the channel mask - 98 * e.g. AUDIO_CHANNEL_OUT_STEREO or AUDIO_CHANNEL_IN_STEREO 99 */ 100 uint32_t (*get_channels)(const struct audio_stream *stream); 101 102 /** 103 * audio format - eg. AUDIO_FORMAT_PCM_16_BIT 104 */ 105 int (*get_format)(const struct audio_stream *stream); 106 107 /* currently unused - use set_parameters with key 108 * AUDIO_PARAMETER_STREAM_FORMAT 109 */ 110 int (*set_format)(struct audio_stream *stream, int format); 111 112 /** 113 * Put the audio hardware input/output into standby mode. 114 * Returns 0 on success and <0 on failure. 115 */ 116 int (*standby)(struct audio_stream *stream); 117 118 /** dump the state of the audio input/output device */ 119 int (*dump)(const struct audio_stream *stream, int fd); 120 121 audio_devices_t (*get_device)(const struct audio_stream *stream); 122 int (*set_device)(struct audio_stream *stream, audio_devices_t device); 123 124 /** 125 * set/get audio stream parameters. The function accepts a list of 126 * parameter key value pairs in the form: key1=value1;key2=value2;... 127 * 128 * Some keys are reserved for standard parameters (See AudioParameter class) 129 * 130 * If the implementation does not accept a parameter change while 131 * the output is active but the parameter is acceptable otherwise, it must 132 * return -ENOSYS. 133 * 134 * The audio flinger will put the stream in standby and then change the 135 * parameter value. 136 */ 137 int (*set_parameters)(struct audio_stream *stream, const char *kv_pairs); 138 139 /* 140 * Returns a pointer to a heap allocated string. The caller is responsible 141 * for freeing the memory for it. 142 */ 143 char * (*get_parameters)(const struct audio_stream *stream, 144 const char *keys); 145 int (*add_audio_effect)(const struct audio_stream *stream, 146 effect_handle_t effect); 147 int (*remove_audio_effect)(const struct audio_stream *stream, 148 effect_handle_t effect); 149 }; 150 typedef struct audio_stream audio_stream_t; 151 152 /** 153 * audio_stream_out is the abstraction interface for the audio output hardware. 154 * 155 * It provides information about various properties of the audio output 156 * hardware driver. 157 */ 158 159 struct audio_stream_out { 160 struct audio_stream common; 161 162 /** 163 * return the audio hardware driver latency in milli seconds. 164 */ 165 uint32_t (*get_latency)(const struct audio_stream_out *stream); 166 167 /** 168 * Use this method in situations where audio mixing is done in the 169 * hardware. This method serves as a direct interface with hardware, 170 * allowing you to directly set the volume as apposed to via the framework. 171 * This method might produce multiple PCM outputs or hardware accelerated 172 * codecs, such as MP3 or AAC. 173 */ 174 int (*set_volume)(struct audio_stream_out *stream, float left, float right); 175 176 /** 177 * write audio buffer to driver. Returns number of bytes written 178 */ 179 ssize_t (*write)(struct audio_stream_out *stream, const void* buffer, 180 size_t bytes); 181 182 /* return the number of audio frames written by the audio dsp to DAC since 183 * the output has exited standby 184 */ 185 int (*get_render_position)(const struct audio_stream_out *stream, 186 uint32_t *dsp_frames); 187 }; 188 typedef struct audio_stream_out audio_stream_out_t; 189 190 struct audio_stream_in { 191 struct audio_stream common; 192 193 /** set the input gain for the audio driver. This method is for 194 * for future use */ 195 int (*set_gain)(struct audio_stream_in *stream, float gain); 196 197 /** read audio buffer in from audio driver */ 198 ssize_t (*read)(struct audio_stream_in *stream, void* buffer, 199 size_t bytes); 200 201 /** 202 * Return the amount of input frames lost in the audio driver since the 203 * last call of this function. 204 * Audio driver is expected to reset the value to 0 and restart counting 205 * upon returning the current value by this function call. 206 * Such loss typically occurs when the user space process is blocked 207 * longer than the capacity of audio driver buffers. 208 * 209 * Unit: the number of input audio frames 210 */ 211 uint32_t (*get_input_frames_lost)(struct audio_stream_in *stream); 212 }; 213 typedef struct audio_stream_in audio_stream_in_t; 214 215 /** 216 * return the frame size (number of bytes per sample). 217 */ 218 static inline uint32_t audio_stream_frame_size(struct audio_stream *s) 219 { 220 int chan_samp_sz; 221 222 switch (s->get_format(s)) { 223 case AUDIO_FORMAT_PCM_16_BIT: 224 chan_samp_sz = sizeof(int16_t); 225 break; 226 case AUDIO_FORMAT_PCM_8_BIT: 227 default: 228 chan_samp_sz = sizeof(int8_t); 229 break; 230 } 231 232 return popcount(s->get_channels(s)) * chan_samp_sz; 233 } 234 235 236 /**********************************************************************/ 237 238 /** 239 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 240 * and the fields of this data structure must begin with hw_module_t 241 * followed by module specific information. 242 */ 243 struct audio_module { 244 struct hw_module_t common; 245 }; 246 247 struct audio_hw_device { 248 struct hw_device_t common; 249 250 /** 251 * used by audio flinger to enumerate what devices are supported by 252 * each audio_hw_device implementation. 253 * 254 * Return value is a bitmask of 1 or more values of audio_devices_t 255 */ 256 uint32_t (*get_supported_devices)(const struct audio_hw_device *dev); 257 258 /** 259 * check to see if the audio hardware interface has been initialized. 260 * returns 0 on success, -ENODEV on failure. 261 */ 262 int (*init_check)(const struct audio_hw_device *dev); 263 264 /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */ 265 int (*set_voice_volume)(struct audio_hw_device *dev, float volume); 266 267 /** 268 * set the audio volume for all audio activities other than voice call. 269 * Range between 0.0 and 1.0. If any value other than 0 is returned, 270 * the software mixer will emulate this capability. 271 */ 272 int (*set_master_volume)(struct audio_hw_device *dev, float volume); 273 274 /** 275 * setMode is called when the audio mode changes. AUDIO_MODE_NORMAL mode 276 * is for standard audio playback, AUDIO_MODE_RINGTONE when a ringtone is 277 * playing, and AUDIO_MODE_IN_CALL when a call is in progress. 278 */ 279 int (*set_mode)(struct audio_hw_device *dev, int mode); 280 281 /* mic mute */ 282 int (*set_mic_mute)(struct audio_hw_device *dev, bool state); 283 int (*get_mic_mute)(const struct audio_hw_device *dev, bool *state); 284 285 /* set/get global audio parameters */ 286 int (*set_parameters)(struct audio_hw_device *dev, const char *kv_pairs); 287 288 /* 289 * Returns a pointer to a heap allocated string. The caller is responsible 290 * for freeing the memory for it. 291 */ 292 char * (*get_parameters)(const struct audio_hw_device *dev, 293 const char *keys); 294 295 /* Returns audio input buffer size according to parameters passed or 296 * 0 if one of the parameters is not supported 297 */ 298 size_t (*get_input_buffer_size)(const struct audio_hw_device *dev, 299 uint32_t sample_rate, int format, 300 int channel_count); 301 302 /** This method creates and opens the audio hardware output stream */ 303 int (*open_output_stream)(struct audio_hw_device *dev, uint32_t devices, 304 int *format, uint32_t *channels, 305 uint32_t *sample_rate, 306 struct audio_stream_out **out); 307 308 void (*close_output_stream)(struct audio_hw_device *dev, 309 struct audio_stream_out* out); 310 311 /** This method creates and opens the audio hardware input stream */ 312 int (*open_input_stream)(struct audio_hw_device *dev, uint32_t devices, 313 int *format, uint32_t *channels, 314 uint32_t *sample_rate, 315 audio_in_acoustics_t acoustics, 316 struct audio_stream_in **stream_in); 317 318 void (*close_input_stream)(struct audio_hw_device *dev, 319 struct audio_stream_in *in); 320 321 /** This method dumps the state of the audio hardware */ 322 int (*dump)(const struct audio_hw_device *dev, int fd); 323 }; 324 typedef struct audio_hw_device audio_hw_device_t; 325 326 /** convenience API for opening and closing a supported device */ 327 328 static inline int audio_hw_device_open(const struct hw_module_t* module, 329 struct audio_hw_device** device) 330 { 331 return module->methods->open(module, AUDIO_HARDWARE_INTERFACE, 332 (struct hw_device_t**)device); 333 } 334 335 static inline int audio_hw_device_close(struct audio_hw_device* device) 336 { 337 return device->common.close(&device->common); 338 } 339 340 341 __END_DECLS 342 343 #endif // ANDROID_AUDIO_INTERFACE_H 344
