• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 /* Use version 0.1 to be compatible with first generation of audio hw module with version_major
46  * hardcoded to 1. No audio module API change.
47  */
48 #define AUDIO_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1)
49 #define AUDIO_MODULE_API_VERSION_CURRENT AUDIO_MODULE_API_VERSION_0_1
50 
51 /* First generation of audio devices had version hardcoded to 0. all devices with versions < 1.0
52  * will be considered of first generation API.
53  */
54 #define AUDIO_DEVICE_API_VERSION_0_0 HARDWARE_DEVICE_API_VERSION(0, 0)
55 #define AUDIO_DEVICE_API_VERSION_1_0 HARDWARE_DEVICE_API_VERSION(1, 0)
56 #define AUDIO_DEVICE_API_VERSION_2_0 HARDWARE_DEVICE_API_VERSION(2, 0)
57 #define AUDIO_DEVICE_API_VERSION_3_0 HARDWARE_DEVICE_API_VERSION(3, 0)
58 #define AUDIO_DEVICE_API_VERSION_CURRENT AUDIO_DEVICE_API_VERSION_3_0
59 /* Minimal audio HAL version supported by the audio framework */
60 #define AUDIO_DEVICE_API_VERSION_MIN AUDIO_DEVICE_API_VERSION_2_0
61 
62 /**
63  * List of known audio HAL modules. This is the base name of the audio HAL
64  * library composed of the "audio." prefix, one of the base names below and
65  * a suffix specific to the device.
66  * e.g: audio.primary.goldfish.so or audio.a2dp.default.so
67  */
68 
69 #define AUDIO_HARDWARE_MODULE_ID_PRIMARY "primary"
70 #define AUDIO_HARDWARE_MODULE_ID_A2DP "a2dp"
71 #define AUDIO_HARDWARE_MODULE_ID_USB "usb"
72 #define AUDIO_HARDWARE_MODULE_ID_REMOTE_SUBMIX "r_submix"
73 #define AUDIO_HARDWARE_MODULE_ID_CODEC_OFFLOAD "codec_offload"
74 
75 /**************************************/
76 
77 /**
78  *  standard audio parameters that the HAL may need to handle
79  */
80 
81 /**
82  *  audio device parameters
83  */
84 
85 /* BT SCO Noise Reduction + Echo Cancellation parameters */
86 #define AUDIO_PARAMETER_KEY_BT_NREC "bt_headset_nrec"
87 #define AUDIO_PARAMETER_VALUE_ON "on"
88 #define AUDIO_PARAMETER_VALUE_OFF "off"
89 
90 /* TTY mode selection */
91 #define AUDIO_PARAMETER_KEY_TTY_MODE "tty_mode"
92 #define AUDIO_PARAMETER_VALUE_TTY_OFF "tty_off"
93 #define AUDIO_PARAMETER_VALUE_TTY_VCO "tty_vco"
94 #define AUDIO_PARAMETER_VALUE_TTY_HCO "tty_hco"
95 #define AUDIO_PARAMETER_VALUE_TTY_FULL "tty_full"
96 
97 /* Hearing Aid Compatibility - Telecoil (HAC-T) mode on/off
98    Strings must be in sync with CallFeaturesSetting.java */
99 #define AUDIO_PARAMETER_KEY_HAC "HACSetting"
100 #define AUDIO_PARAMETER_VALUE_HAC_ON "ON"
101 #define AUDIO_PARAMETER_VALUE_HAC_OFF "OFF"
102 
103 /* A2DP sink address set by framework */
104 #define AUDIO_PARAMETER_A2DP_SINK_ADDRESS "a2dp_sink_address"
105 
106 /* A2DP source address set by framework */
107 #define AUDIO_PARAMETER_A2DP_SOURCE_ADDRESS "a2dp_source_address"
108 
109 /* Screen state */
110 #define AUDIO_PARAMETER_KEY_SCREEN_STATE "screen_state"
111 
112 /* Bluetooth SCO wideband */
113 #define AUDIO_PARAMETER_KEY_BT_SCO_WB "bt_wbs"
114 
115 /* Get a new HW synchronization source identifier.
116  * Return a valid source (positive integer) or AUDIO_HW_SYNC_INVALID if an error occurs
117  * or no HW sync is available. */
118 #define AUDIO_PARAMETER_HW_AV_SYNC "hw_av_sync"
119 
120 /**
121  *  audio stream parameters
122  */
123 
124 #define AUDIO_PARAMETER_STREAM_ROUTING "routing"             /* audio_devices_t */
125 #define AUDIO_PARAMETER_STREAM_FORMAT "format"               /* audio_format_t */
126 #define AUDIO_PARAMETER_STREAM_CHANNELS "channels"           /* audio_channel_mask_t */
127 #define AUDIO_PARAMETER_STREAM_FRAME_COUNT "frame_count"     /* size_t */
128 #define AUDIO_PARAMETER_STREAM_INPUT_SOURCE "input_source"   /* audio_source_t */
129 #define AUDIO_PARAMETER_STREAM_SAMPLING_RATE "sampling_rate" /* uint32_t */
130 
131 #define AUDIO_PARAMETER_DEVICE_CONNECT "connect"            /* audio_devices_t */
132 #define AUDIO_PARAMETER_DEVICE_DISCONNECT "disconnect"      /* audio_devices_t */
133 
134 /* Query supported formats. The response is a '|' separated list of strings from
135  * audio_format_t enum e.g: "sup_formats=AUDIO_FORMAT_PCM_16_BIT" */
136 #define AUDIO_PARAMETER_STREAM_SUP_FORMATS "sup_formats"
137 /* Query supported channel masks. The response is a '|' separated list of strings from
138  * audio_channel_mask_t enum e.g: "sup_channels=AUDIO_CHANNEL_OUT_STEREO|AUDIO_CHANNEL_OUT_MONO" */
139 #define AUDIO_PARAMETER_STREAM_SUP_CHANNELS "sup_channels"
140 /* Query supported sampling rates. The response is a '|' separated list of integer values e.g:
141  * "sup_sampling_rates=44100|48000" */
142 #define AUDIO_PARAMETER_STREAM_SUP_SAMPLING_RATES "sup_sampling_rates"
143 
144 /* Set the HW synchronization source for an output stream. */
145 #define AUDIO_PARAMETER_STREAM_HW_AV_SYNC "hw_av_sync"
146 
147 /* Enable mono audio playback if 1, else should be 0. */
148 #define AUDIO_PARAMETER_MONO_OUTPUT "mono_output"
149 
150 /**
151  * audio codec parameters
152  */
153 
154 #define AUDIO_OFFLOAD_CODEC_PARAMS "music_offload_codec_param"
155 #define AUDIO_OFFLOAD_CODEC_BIT_PER_SAMPLE "music_offload_bit_per_sample"
156 #define AUDIO_OFFLOAD_CODEC_BIT_RATE "music_offload_bit_rate"
157 #define AUDIO_OFFLOAD_CODEC_AVG_BIT_RATE "music_offload_avg_bit_rate"
158 #define AUDIO_OFFLOAD_CODEC_ID "music_offload_codec_id"
159 #define AUDIO_OFFLOAD_CODEC_BLOCK_ALIGN "music_offload_block_align"
160 #define AUDIO_OFFLOAD_CODEC_SAMPLE_RATE "music_offload_sample_rate"
161 #define AUDIO_OFFLOAD_CODEC_ENCODE_OPTION "music_offload_encode_option"
162 #define AUDIO_OFFLOAD_CODEC_NUM_CHANNEL  "music_offload_num_channels"
163 #define AUDIO_OFFLOAD_CODEC_DOWN_SAMPLING  "music_offload_down_sampling"
164 #define AUDIO_OFFLOAD_CODEC_DELAY_SAMPLES  "delay_samples"
165 #define AUDIO_OFFLOAD_CODEC_PADDING_SAMPLES  "padding_samples"
166 
167 /**************************************/
168 
169 /* common audio stream parameters and operations */
170 struct audio_stream {
171 
172     /**
173      * Return the sampling rate in Hz - eg. 44100.
174      */
175     uint32_t (*get_sample_rate)(const struct audio_stream *stream);
176 
177     /* currently unused - use set_parameters with key
178      *    AUDIO_PARAMETER_STREAM_SAMPLING_RATE
179      */
180     int (*set_sample_rate)(struct audio_stream *stream, uint32_t rate);
181 
182     /**
183      * Return size of input/output buffer in bytes for this stream - eg. 4800.
184      * It should be a multiple of the frame size.  See also get_input_buffer_size.
185      */
186     size_t (*get_buffer_size)(const struct audio_stream *stream);
187 
188     /**
189      * Return the channel mask -
190      *  e.g. AUDIO_CHANNEL_OUT_STEREO or AUDIO_CHANNEL_IN_STEREO
191      */
192     audio_channel_mask_t (*get_channels)(const struct audio_stream *stream);
193 
194     /**
195      * Return the audio format - e.g. AUDIO_FORMAT_PCM_16_BIT
196      */
197     audio_format_t (*get_format)(const struct audio_stream *stream);
198 
199     /* currently unused - use set_parameters with key
200      *     AUDIO_PARAMETER_STREAM_FORMAT
201      */
202     int (*set_format)(struct audio_stream *stream, audio_format_t format);
203 
204     /**
205      * Put the audio hardware input/output into standby mode.
206      * Driver should exit from standby mode at the next I/O operation.
207      * Returns 0 on success and <0 on failure.
208      */
209     int (*standby)(struct audio_stream *stream);
210 
211     /** dump the state of the audio input/output device */
212     int (*dump)(const struct audio_stream *stream, int fd);
213 
214     /** Return the set of device(s) which this stream is connected to */
215     audio_devices_t (*get_device)(const struct audio_stream *stream);
216 
217     /**
218      * Currently unused - set_device() corresponds to set_parameters() with key
219      * AUDIO_PARAMETER_STREAM_ROUTING for both input and output.
220      * AUDIO_PARAMETER_STREAM_INPUT_SOURCE is an additional information used by
221      * input streams only.
222      */
223     int (*set_device)(struct audio_stream *stream, audio_devices_t device);
224 
225     /**
226      * set/get audio stream parameters. The function accepts a list of
227      * parameter key value pairs in the form: key1=value1;key2=value2;...
228      *
229      * Some keys are reserved for standard parameters (See AudioParameter class)
230      *
231      * If the implementation does not accept a parameter change while
232      * the output is active but the parameter is acceptable otherwise, it must
233      * return -ENOSYS.
234      *
235      * The audio flinger will put the stream in standby and then change the
236      * parameter value.
237      */
238     int (*set_parameters)(struct audio_stream *stream, const char *kv_pairs);
239 
240     /*
241      * Returns a pointer to a heap allocated string. The caller is responsible
242      * for freeing the memory for it using free().
243      */
244     char * (*get_parameters)(const struct audio_stream *stream,
245                              const char *keys);
246     int (*add_audio_effect)(const struct audio_stream *stream,
247                              effect_handle_t effect);
248     int (*remove_audio_effect)(const struct audio_stream *stream,
249                              effect_handle_t effect);
250 };
251 typedef struct audio_stream audio_stream_t;
252 
253 /* type of asynchronous write callback events. Mutually exclusive */
254 typedef enum {
255     STREAM_CBK_EVENT_WRITE_READY, /* non blocking write completed */
256     STREAM_CBK_EVENT_DRAIN_READY,  /* drain completed */
257     STREAM_CBK_EVENT_ERROR, /* stream hit some error, let AF take action */
258 } stream_callback_event_t;
259 
260 typedef int (*stream_callback_t)(stream_callback_event_t event, void *param, void *cookie);
261 
262 /* type of drain requested to audio_stream_out->drain(). Mutually exclusive */
263 typedef enum {
264     AUDIO_DRAIN_ALL,            /* drain() returns when all data has been played */
265     AUDIO_DRAIN_EARLY_NOTIFY    /* drain() returns a short time before all data
266                                    from the current track has been played to
267                                    give time for gapless track switch */
268 } audio_drain_type_t;
269 
270 /**
271  * audio_stream_out is the abstraction interface for the audio output hardware.
272  *
273  * It provides information about various properties of the audio output
274  * hardware driver.
275  */
276 
277 struct audio_stream_out {
278     /**
279      * Common methods of the audio stream out.  This *must* be the first member of audio_stream_out
280      * as users of this structure will cast a audio_stream to audio_stream_out pointer in contexts
281      * where it's known the audio_stream references an audio_stream_out.
282      */
283     struct audio_stream common;
284 
285     /**
286      * Return the audio hardware driver estimated latency in milliseconds.
287      */
288     uint32_t (*get_latency)(const struct audio_stream_out *stream);
289 
290     /**
291      * Use this method in situations where audio mixing is done in the
292      * hardware. This method serves as a direct interface with hardware,
293      * allowing you to directly set the volume as apposed to via the framework.
294      * This method might produce multiple PCM outputs or hardware accelerated
295      * codecs, such as MP3 or AAC.
296      */
297     int (*set_volume)(struct audio_stream_out *stream, float left, float right);
298 
299     /**
300      * Write audio buffer to driver. Returns number of bytes written, or a
301      * negative status_t. If at least one frame was written successfully prior to the error,
302      * it is suggested that the driver return that successful (short) byte count
303      * and then return an error in the subsequent call.
304      *
305      * If set_callback() has previously been called to enable non-blocking mode
306      * the write() is not allowed to block. It must write only the number of
307      * bytes that currently fit in the driver/hardware buffer and then return
308      * this byte count. If this is less than the requested write size the
309      * callback function must be called when more space is available in the
310      * driver/hardware buffer.
311      */
312     ssize_t (*write)(struct audio_stream_out *stream, const void* buffer,
313                      size_t bytes);
314 
315     /* return the number of audio frames written by the audio dsp to DAC since
316      * the output has exited standby
317      */
318     int (*get_render_position)(const struct audio_stream_out *stream,
319                                uint32_t *dsp_frames);
320 
321     /**
322      * get the local time at which the next write to the audio driver will be presented.
323      * The units are microseconds, where the epoch is decided by the local audio HAL.
324      */
325     int (*get_next_write_timestamp)(const struct audio_stream_out *stream,
326                                     int64_t *timestamp);
327 
328     /**
329      * set the callback function for notifying completion of non-blocking
330      * write and drain.
331      * Calling this function implies that all future write() and drain()
332      * must be non-blocking and use the callback to signal completion.
333      */
334     int (*set_callback)(struct audio_stream_out *stream,
335             stream_callback_t callback, void *cookie);
336 
337     /**
338      * Notifies to the audio driver to stop playback however the queued buffers are
339      * retained by the hardware. Useful for implementing pause/resume. Empty implementation
340      * if not supported however should be implemented for hardware with non-trivial
341      * latency. In the pause state audio hardware could still be using power. User may
342      * consider calling suspend after a timeout.
343      *
344      * Implementation of this function is mandatory for offloaded playback.
345      */
346     int (*pause)(struct audio_stream_out* stream);
347 
348     /**
349      * Notifies to the audio driver to resume playback following a pause.
350      * Returns error if called without matching pause.
351      *
352      * Implementation of this function is mandatory for offloaded playback.
353      */
354     int (*resume)(struct audio_stream_out* stream);
355 
356     /**
357      * Requests notification when data buffered by the driver/hardware has
358      * been played. If set_callback() has previously been called to enable
359      * non-blocking mode, the drain() must not block, instead it should return
360      * quickly and completion of the drain is notified through the callback.
361      * If set_callback() has not been called, the drain() must block until
362      * completion.
363      * If type==AUDIO_DRAIN_ALL, the drain completes when all previously written
364      * data has been played.
365      * If type==AUDIO_DRAIN_EARLY_NOTIFY, the drain completes shortly before all
366      * data for the current track has played to allow time for the framework
367      * to perform a gapless track switch.
368      *
369      * Drain must return immediately on stop() and flush() call
370      *
371      * Implementation of this function is mandatory for offloaded playback.
372      */
373     int (*drain)(struct audio_stream_out* stream, audio_drain_type_t type );
374 
375     /**
376      * Notifies to the audio driver to flush the queued data. Stream must already
377      * be paused before calling flush().
378      *
379      * Implementation of this function is mandatory for offloaded playback.
380      */
381    int (*flush)(struct audio_stream_out* stream);
382 
383     /**
384      * Return a recent count of the number of audio frames presented to an external observer.
385      * This excludes frames which have been written but are still in the pipeline.
386      * The count is not reset to zero when output enters standby.
387      * Also returns the value of CLOCK_MONOTONIC as of this presentation count.
388      * The returned count is expected to be 'recent',
389      * but does not need to be the most recent possible value.
390      * However, the associated time should correspond to whatever count is returned.
391      * Example:  assume that N+M frames have been presented, where M is a 'small' number.
392      * Then it is permissible to return N instead of N+M,
393      * and the timestamp should correspond to N rather than N+M.
394      * The terms 'recent' and 'small' are not defined.
395      * They reflect the quality of the implementation.
396      *
397      * 3.0 and higher only.
398      */
399     int (*get_presentation_position)(const struct audio_stream_out *stream,
400                                uint64_t *frames, struct timespec *timestamp);
401 
402 };
403 typedef struct audio_stream_out audio_stream_out_t;
404 
405 struct audio_stream_in {
406     /**
407      * Common methods of the audio stream in.  This *must* be the first member of audio_stream_in
408      * as users of this structure will cast a audio_stream to audio_stream_in pointer in contexts
409      * where it's known the audio_stream references an audio_stream_in.
410      */
411     struct audio_stream common;
412 
413     /** set the input gain for the audio driver. This method is for
414      *  for future use */
415     int (*set_gain)(struct audio_stream_in *stream, float gain);
416 
417     /** Read audio buffer in from audio driver. Returns number of bytes read, or a
418      *  negative status_t. If at least one frame was read prior to the error,
419      *  read should return that byte count and then return an error in the subsequent call.
420      */
421     ssize_t (*read)(struct audio_stream_in *stream, void* buffer,
422                     size_t bytes);
423 
424     /**
425      * Return the amount of input frames lost in the audio driver since the
426      * last call of this function.
427      * Audio driver is expected to reset the value to 0 and restart counting
428      * upon returning the current value by this function call.
429      * Such loss typically occurs when the user space process is blocked
430      * longer than the capacity of audio driver buffers.
431      *
432      * Unit: the number of input audio frames
433      */
434     uint32_t (*get_input_frames_lost)(struct audio_stream_in *stream);
435 
436     /**
437      * Return a recent count of the number of audio frames received and
438      * the clock time associated with that frame count.
439      *
440      * frames is the total frame count received. This should be as early in
441      *     the capture pipeline as possible. In general,
442      *     frames should be non-negative and should not go "backwards".
443      *
444      * time is the clock MONOTONIC time when frames was measured. In general,
445      *     time should be a positive quantity and should not go "backwards".
446      *
447      * The status returned is 0 on success, -ENOSYS if the device is not
448      * ready/available, or -EINVAL if the arguments are null or otherwise invalid.
449      */
450     int (*get_capture_position)(const struct audio_stream_in *stream,
451                                 int64_t *frames, int64_t *time);
452 };
453 typedef struct audio_stream_in audio_stream_in_t;
454 
455 /**
456  * return the frame size (number of bytes per sample).
457  *
458  * Deprecated: use audio_stream_out_frame_size() or audio_stream_in_frame_size() instead.
459  */
460 __attribute__((__deprecated__))
audio_stream_frame_size(const struct audio_stream * s)461 static inline size_t audio_stream_frame_size(const struct audio_stream *s)
462 {
463     size_t chan_samp_sz;
464     audio_format_t format = s->get_format(s);
465 
466     if (audio_has_proportional_frames(format)) {
467         chan_samp_sz = audio_bytes_per_sample(format);
468         return popcount(s->get_channels(s)) * chan_samp_sz;
469     }
470 
471     return sizeof(int8_t);
472 }
473 
474 /**
475  * return the frame size (number of bytes per sample) of an output stream.
476  */
audio_stream_out_frame_size(const struct audio_stream_out * s)477 static inline size_t audio_stream_out_frame_size(const struct audio_stream_out *s)
478 {
479     size_t chan_samp_sz;
480     audio_format_t format = s->common.get_format(&s->common);
481 
482     if (audio_has_proportional_frames(format)) {
483         chan_samp_sz = audio_bytes_per_sample(format);
484         return audio_channel_count_from_out_mask(s->common.get_channels(&s->common)) * chan_samp_sz;
485     }
486 
487     return sizeof(int8_t);
488 }
489 
490 /**
491  * return the frame size (number of bytes per sample) of an input stream.
492  */
audio_stream_in_frame_size(const struct audio_stream_in * s)493 static inline size_t audio_stream_in_frame_size(const struct audio_stream_in *s)
494 {
495     size_t chan_samp_sz;
496     audio_format_t format = s->common.get_format(&s->common);
497 
498     if (audio_has_proportional_frames(format)) {
499         chan_samp_sz = audio_bytes_per_sample(format);
500         return audio_channel_count_from_in_mask(s->common.get_channels(&s->common)) * chan_samp_sz;
501     }
502 
503     return sizeof(int8_t);
504 }
505 
506 /**********************************************************************/
507 
508 /**
509  * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
510  * and the fields of this data structure must begin with hw_module_t
511  * followed by module specific information.
512  */
513 struct audio_module {
514     struct hw_module_t common;
515 };
516 
517 struct audio_hw_device {
518     /**
519      * Common methods of the audio device.  This *must* be the first member of audio_hw_device
520      * as users of this structure will cast a hw_device_t to audio_hw_device pointer in contexts
521      * where it's known the hw_device_t references an audio_hw_device.
522      */
523     struct hw_device_t common;
524 
525     /**
526      * used by audio flinger to enumerate what devices are supported by
527      * each audio_hw_device implementation.
528      *
529      * Return value is a bitmask of 1 or more values of audio_devices_t
530      *
531      * NOTE: audio HAL implementations starting with
532      * AUDIO_DEVICE_API_VERSION_2_0 do not implement this function.
533      * All supported devices should be listed in audio_policy.conf
534      * file and the audio policy manager must choose the appropriate
535      * audio module based on information in this file.
536      */
537     uint32_t (*get_supported_devices)(const struct audio_hw_device *dev);
538 
539     /**
540      * check to see if the audio hardware interface has been initialized.
541      * returns 0 on success, -ENODEV on failure.
542      */
543     int (*init_check)(const struct audio_hw_device *dev);
544 
545     /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */
546     int (*set_voice_volume)(struct audio_hw_device *dev, float volume);
547 
548     /**
549      * set the audio volume for all audio activities other than voice call.
550      * Range between 0.0 and 1.0. If any value other than 0 is returned,
551      * the software mixer will emulate this capability.
552      */
553     int (*set_master_volume)(struct audio_hw_device *dev, float volume);
554 
555     /**
556      * Get the current master volume value for the HAL, if the HAL supports
557      * master volume control.  AudioFlinger will query this value from the
558      * primary audio HAL when the service starts and use the value for setting
559      * the initial master volume across all HALs.  HALs which do not support
560      * this method may leave it set to NULL.
561      */
562     int (*get_master_volume)(struct audio_hw_device *dev, float *volume);
563 
564     /**
565      * set_mode is called when the audio mode changes. AUDIO_MODE_NORMAL mode
566      * is for standard audio playback, AUDIO_MODE_RINGTONE when a ringtone is
567      * playing, and AUDIO_MODE_IN_CALL when a call is in progress.
568      */
569     int (*set_mode)(struct audio_hw_device *dev, audio_mode_t mode);
570 
571     /* mic mute */
572     int (*set_mic_mute)(struct audio_hw_device *dev, bool state);
573     int (*get_mic_mute)(const struct audio_hw_device *dev, bool *state);
574 
575     /* set/get global audio parameters */
576     int (*set_parameters)(struct audio_hw_device *dev, const char *kv_pairs);
577 
578     /*
579      * Returns a pointer to a heap allocated string. The caller is responsible
580      * for freeing the memory for it using free().
581      */
582     char * (*get_parameters)(const struct audio_hw_device *dev,
583                              const char *keys);
584 
585     /* Returns audio input buffer size according to parameters passed or
586      * 0 if one of the parameters is not supported.
587      * See also get_buffer_size which is for a particular stream.
588      */
589     size_t (*get_input_buffer_size)(const struct audio_hw_device *dev,
590                                     const struct audio_config *config);
591 
592     /** This method creates and opens the audio hardware output stream.
593      * The "address" parameter qualifies the "devices" audio device type if needed.
594      * The format format depends on the device type:
595      * - Bluetooth devices use the MAC address of the device in the form "00:11:22:AA:BB:CC"
596      * - USB devices use the ALSA card and device numbers in the form  "card=X;device=Y"
597      * - Other devices may use a number or any other string.
598      */
599 
600     int (*open_output_stream)(struct audio_hw_device *dev,
601                               audio_io_handle_t handle,
602                               audio_devices_t devices,
603                               audio_output_flags_t flags,
604                               struct audio_config *config,
605                               struct audio_stream_out **stream_out,
606                               const char *address);
607 
608     void (*close_output_stream)(struct audio_hw_device *dev,
609                                 struct audio_stream_out* stream_out);
610 
611     /** This method creates and opens the audio hardware input stream */
612     int (*open_input_stream)(struct audio_hw_device *dev,
613                              audio_io_handle_t handle,
614                              audio_devices_t devices,
615                              struct audio_config *config,
616                              struct audio_stream_in **stream_in,
617                              audio_input_flags_t flags,
618                              const char *address,
619                              audio_source_t source);
620 
621     void (*close_input_stream)(struct audio_hw_device *dev,
622                                struct audio_stream_in *stream_in);
623 
624     /** This method dumps the state of the audio hardware */
625     int (*dump)(const struct audio_hw_device *dev, int fd);
626 
627     /**
628      * set the audio mute status for all audio activities.  If any value other
629      * than 0 is returned, the software mixer will emulate this capability.
630      */
631     int (*set_master_mute)(struct audio_hw_device *dev, bool mute);
632 
633     /**
634      * Get the current master mute status for the HAL, if the HAL supports
635      * master mute control.  AudioFlinger will query this value from the primary
636      * audio HAL when the service starts and use the value for setting the
637      * initial master mute across all HALs.  HALs which do not support this
638      * method may leave it set to NULL.
639      */
640     int (*get_master_mute)(struct audio_hw_device *dev, bool *mute);
641 
642     /**
643      * Routing control
644      */
645 
646     /* Creates an audio patch between several source and sink ports.
647      * The handle is allocated by the HAL and should be unique for this
648      * audio HAL module. */
649     int (*create_audio_patch)(struct audio_hw_device *dev,
650                                unsigned int num_sources,
651                                const struct audio_port_config *sources,
652                                unsigned int num_sinks,
653                                const struct audio_port_config *sinks,
654                                audio_patch_handle_t *handle);
655 
656     /* Release an audio patch */
657     int (*release_audio_patch)(struct audio_hw_device *dev,
658                                audio_patch_handle_t handle);
659 
660     /* Fills the list of supported attributes for a given audio port.
661      * As input, "port" contains the information (type, role, address etc...)
662      * needed by the HAL to identify the port.
663      * As output, "port" contains possible attributes (sampling rates, formats,
664      * channel masks, gain controllers...) for this port.
665      */
666     int (*get_audio_port)(struct audio_hw_device *dev,
667                           struct audio_port *port);
668 
669     /* Set audio port configuration */
670     int (*set_audio_port_config)(struct audio_hw_device *dev,
671                          const struct audio_port_config *config);
672 
673 };
674 typedef struct audio_hw_device audio_hw_device_t;
675 
676 /** convenience API for opening and closing a supported device */
677 
audio_hw_device_open(const struct hw_module_t * module,struct audio_hw_device ** device)678 static inline int audio_hw_device_open(const struct hw_module_t* module,
679                                        struct audio_hw_device** device)
680 {
681     return module->methods->open(module, AUDIO_HARDWARE_INTERFACE,
682                                  (struct hw_device_t**)device);
683 }
684 
audio_hw_device_close(struct audio_hw_device * device)685 static inline int audio_hw_device_close(struct audio_hw_device* device)
686 {
687     return device->common.close(&device->common);
688 }
689 
690 
691 __END_DECLS
692 
693 #endif  // ANDROID_AUDIO_INTERFACE_H
694