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_POLICY_INTERFACE_H
19#define ANDROID_AUDIO_POLICY_INTERFACE_H
20
21#include <stdint.h>
22#include <sys/cdefs.h>
23#include <sys/types.h>
24
25#include <hardware/hardware.h>
26
27#include <system/audio.h>
28#include <system/audio_policy.h>
29
30__BEGIN_DECLS
31
32/**
33 * The id of this module
34 */
35#define AUDIO_POLICY_HARDWARE_MODULE_ID "audio_policy"
36
37/**
38 * Name of the audio devices to open
39 */
40#define AUDIO_POLICY_INTERFACE "policy"
41
42/* ---------------------------------------------------------------------------- */
43
44/*
45 * The audio_policy and audio_policy_service_ops structs define the
46 * communication interfaces between the platform specific audio policy manager
47 * and Android generic audio policy manager.
48 * The platform specific audio policy manager must implement methods of the
49 * audio_policy struct.
50 * This implementation makes use of the audio_policy_service_ops to control
51 * the activity and configuration of audio input and output streams.
52 *
53 * The platform specific audio policy manager is in charge of the audio
54 * routing and volume control policies for a given platform.
55 * The main roles of this module are:
56 *   - keep track of current system state (removable device connections, phone
57 *     state, user requests...).
58 *   System state changes and user actions are notified to audio policy
59 *   manager with methods of the audio_policy.
60 *
61 *   - process get_output() queries received when AudioTrack objects are
62 *     created: Those queries return a handler on an output that has been
63 *     selected, configured and opened by the audio policy manager and that
64 *     must be used by the AudioTrack when registering to the AudioFlinger
65 *     with the createTrack() method.
66 *   When the AudioTrack object is released, a release_output() query
67 *   is received and the audio policy manager can decide to close or
68 *   reconfigure the output depending on other streams using this output and
69 *   current system state.
70 *
71 *   - similarly process get_input() and release_input() queries received from
72 *     AudioRecord objects and configure audio inputs.
73 *   - process volume control requests: the stream volume is converted from
74 *     an index value (received from UI) to a float value applicable to each
75 *     output as a function of platform specific settings and current output
76 *     route (destination device). It also make sure that streams are not
77 *     muted if not allowed (e.g. camera shutter sound in some countries).
78 */
79
80/* XXX: this should be defined OUTSIDE of frameworks/base */
81struct effect_descriptor_s;
82
83struct audio_policy {
84    /*
85     * configuration functions
86     */
87
88    /* indicate a change in device connection status */
89    int (*set_device_connection_state)(struct audio_policy *pol,
90                                       audio_devices_t device,
91                                       audio_policy_dev_state_t state,
92                                       const char *device_address);
93
94    /* retrieve a device connection status */
95    audio_policy_dev_state_t (*get_device_connection_state)(
96                                            const struct audio_policy *pol,
97                                            audio_devices_t device,
98                                            const char *device_address);
99
100    /* indicate a change in phone state. Valid phones states are defined
101     * by audio_mode_t */
102    void (*set_phone_state)(struct audio_policy *pol, audio_mode_t state);
103
104    /* deprecated, never called (was "indicate a change in ringer mode") */
105    void (*set_ringer_mode)(struct audio_policy *pol, uint32_t mode,
106                            uint32_t mask);
107
108    /* force using a specific device category for the specified usage */
109    void (*set_force_use)(struct audio_policy *pol,
110                          audio_policy_force_use_t usage,
111                          audio_policy_forced_cfg_t config);
112
113    /* retrieve current device category forced for a given usage */
114    audio_policy_forced_cfg_t (*get_force_use)(const struct audio_policy *pol,
115                                               audio_policy_force_use_t usage);
116
117    /* if can_mute is true, then audio streams that are marked ENFORCED_AUDIBLE
118     * can still be muted. */
119    void (*set_can_mute_enforced_audible)(struct audio_policy *pol,
120                                          bool can_mute);
121
122    /* check proper initialization */
123    int (*init_check)(const struct audio_policy *pol);
124
125    /*
126     * Audio routing query functions
127     */
128
129    /* request an output appropriate for playback of the supplied stream type and
130     * parameters */
131    audio_io_handle_t (*get_output)(struct audio_policy *pol,
132                                    audio_stream_type_t stream,
133                                    uint32_t samplingRate,
134                                    audio_format_t format,
135                                    audio_channel_mask_t channelMask,
136                                    audio_output_flags_t flags);
137
138    /* indicates to the audio policy manager that the output starts being used
139     * by corresponding stream. */
140    int (*start_output)(struct audio_policy *pol,
141                        audio_io_handle_t output,
142                        audio_stream_type_t stream,
143                        int session);
144
145    /* indicates to the audio policy manager that the output stops being used
146     * by corresponding stream. */
147    int (*stop_output)(struct audio_policy *pol,
148                       audio_io_handle_t output,
149                       audio_stream_type_t stream,
150                       int session);
151
152    /* releases the output. */
153    void (*release_output)(struct audio_policy *pol, audio_io_handle_t output);
154
155    /* request an input appropriate for record from the supplied device with
156     * supplied parameters. */
157    audio_io_handle_t (*get_input)(struct audio_policy *pol, audio_source_t inputSource,
158                                   uint32_t samplingRate,
159                                   audio_format_t format,
160                                   audio_channel_mask_t channelMask,
161                                   audio_in_acoustics_t acoustics);
162
163    /* indicates to the audio policy manager that the input starts being used */
164    int (*start_input)(struct audio_policy *pol, audio_io_handle_t input);
165
166    /* indicates to the audio policy manager that the input stops being used. */
167    int (*stop_input)(struct audio_policy *pol, audio_io_handle_t input);
168
169    /* releases the input. */
170    void (*release_input)(struct audio_policy *pol, audio_io_handle_t input);
171
172    /*
173     * volume control functions
174     */
175
176    /* initialises stream volume conversion parameters by specifying volume
177     * index range. The index range for each stream is defined by AudioService. */
178    void (*init_stream_volume)(struct audio_policy *pol,
179                               audio_stream_type_t stream,
180                               int index_min,
181                               int index_max);
182
183    /* sets the new stream volume at a level corresponding to the supplied
184     * index. The index is within the range specified by init_stream_volume() */
185    int (*set_stream_volume_index)(struct audio_policy *pol,
186                                   audio_stream_type_t stream,
187                                   int index);
188
189    /* retrieve current volume index for the specified stream */
190    int (*get_stream_volume_index)(const struct audio_policy *pol,
191                                   audio_stream_type_t stream,
192                                   int *index);
193
194    /* sets the new stream volume at a level corresponding to the supplied
195     * index for the specified device.
196     * The index is within the range specified by init_stream_volume() */
197    int (*set_stream_volume_index_for_device)(struct audio_policy *pol,
198                                   audio_stream_type_t stream,
199                                   int index,
200                                   audio_devices_t device);
201
202    /* retrieve current volume index for the specified stream for the specified device */
203    int (*get_stream_volume_index_for_device)(const struct audio_policy *pol,
204                                   audio_stream_type_t stream,
205                                   int *index,
206                                   audio_devices_t device);
207
208    /* return the strategy corresponding to a given stream type */
209    uint32_t (*get_strategy_for_stream)(const struct audio_policy *pol,
210                                        audio_stream_type_t stream);
211
212    /* return the enabled output devices for the given stream type */
213    audio_devices_t (*get_devices_for_stream)(const struct audio_policy *pol,
214                                       audio_stream_type_t stream);
215
216    /* Audio effect management */
217    audio_io_handle_t (*get_output_for_effect)(struct audio_policy *pol,
218                                            const struct effect_descriptor_s *desc);
219
220    int (*register_effect)(struct audio_policy *pol,
221                           const struct effect_descriptor_s *desc,
222                           audio_io_handle_t output,
223                           uint32_t strategy,
224                           int session,
225                           int id);
226
227    int (*unregister_effect)(struct audio_policy *pol, int id);
228
229    int (*set_effect_enabled)(struct audio_policy *pol, int id, bool enabled);
230
231    bool (*is_stream_active)(const struct audio_policy *pol,
232                             audio_stream_type_t stream,
233                             uint32_t in_past_ms);
234
235    bool (*is_source_active)(const struct audio_policy *pol,
236                             audio_source_t source);
237
238    /* dump state */
239    int (*dump)(const struct audio_policy *pol, int fd);
240};
241
242/* audio hw module handle used by load_hw_module(), open_output_on_module()
243 * and open_input_on_module() */
244typedef int audio_module_handle_t;
245
246struct audio_policy_service_ops {
247    /*
248     * Audio output Control functions
249     */
250
251    /* Opens an audio output with the requested parameters.
252     *
253     * The parameter values can indicate to use the default values in case the
254     * audio policy manager has no specific requirements for the output being
255     * opened.
256     *
257     * When the function returns, the parameter values reflect the actual
258     * values used by the audio hardware output stream.
259     *
260     * The audio policy manager can check if the proposed parameters are
261     * suitable or not and act accordingly.
262     */
263    audio_io_handle_t (*open_output)(void *service,
264                                     audio_devices_t *pDevices,
265                                     uint32_t *pSamplingRate,
266                                     audio_format_t *pFormat,
267                                     audio_channel_mask_t *pChannelMask,
268                                     uint32_t *pLatencyMs,
269                                     audio_output_flags_t flags);
270
271    /* creates a special output that is duplicated to the two outputs passed as
272     * arguments. The duplication is performed by
273     * a special mixer thread in the AudioFlinger.
274     */
275    audio_io_handle_t (*open_duplicate_output)(void *service,
276                                               audio_io_handle_t output1,
277                                               audio_io_handle_t output2);
278
279    /* closes the output stream */
280    int (*close_output)(void *service, audio_io_handle_t output);
281
282    /* suspends the output.
283     *
284     * When an output is suspended, the corresponding audio hardware output
285     * stream is placed in standby and the AudioTracks attached to the mixer
286     * thread are still processed but the output mix is discarded.
287     */
288    int (*suspend_output)(void *service, audio_io_handle_t output);
289
290    /* restores a suspended output. */
291    int (*restore_output)(void *service, audio_io_handle_t output);
292
293    /* */
294    /* Audio input Control functions */
295    /* */
296
297    /* opens an audio input
298     * deprecated - new implementations should use open_input_on_module,
299     * and the acoustics parameter is ignored
300     */
301    audio_io_handle_t (*open_input)(void *service,
302                                    audio_devices_t *pDevices,
303                                    uint32_t *pSamplingRate,
304                                    audio_format_t *pFormat,
305                                    audio_channel_mask_t *pChannelMask,
306                                    audio_in_acoustics_t acoustics);
307
308    /* closes an audio input */
309    int (*close_input)(void *service, audio_io_handle_t input);
310
311    /* */
312    /* misc control functions */
313    /* */
314
315    /* set a stream volume for a particular output.
316     *
317     * For the same user setting, a given stream type can have different
318     * volumes for each output (destination device) it is attached to.
319     */
320    int (*set_stream_volume)(void *service,
321                             audio_stream_type_t stream,
322                             float volume,
323                             audio_io_handle_t output,
324                             int delay_ms);
325
326    /* reroute a given stream type to the specified output */
327    int (*set_stream_output)(void *service,
328                             audio_stream_type_t stream,
329                             audio_io_handle_t output);
330
331    /* function enabling to send proprietary informations directly from audio
332     * policy manager to audio hardware interface. */
333    void (*set_parameters)(void *service,
334                           audio_io_handle_t io_handle,
335                           const char *kv_pairs,
336                           int delay_ms);
337
338    /* function enabling to receive proprietary informations directly from
339     * audio hardware interface to audio policy manager.
340     *
341     * Returns a pointer to a heap allocated string. The caller is responsible
342     * for freeing the memory for it using free().
343     */
344
345    char * (*get_parameters)(void *service, audio_io_handle_t io_handle,
346                             const char *keys);
347
348    /* request the playback of a tone on the specified stream.
349     * used for instance to replace notification sounds when playing over a
350     * telephony device during a phone call.
351     */
352    int (*start_tone)(void *service,
353                      audio_policy_tone_t tone,
354                      audio_stream_type_t stream);
355
356    int (*stop_tone)(void *service);
357
358    /* set down link audio volume. */
359    int (*set_voice_volume)(void *service,
360                            float volume,
361                            int delay_ms);
362
363    /* move effect to the specified output */
364    int (*move_effects)(void *service,
365                        int session,
366                        audio_io_handle_t src_output,
367                        audio_io_handle_t dst_output);
368
369    /* loads an audio hw module.
370     *
371     * The module name passed is the base name of the HW module library, e.g "primary" or "a2dp".
372     * The function returns a handle on the module that will be used to specify a particular
373     * module when calling open_output_on_module() or open_input_on_module()
374     */
375    audio_module_handle_t (*load_hw_module)(void *service,
376                                              const char *name);
377
378    /* Opens an audio output on a particular HW module.
379     *
380     * Same as open_output() but specifying a specific HW module on which the output must be opened.
381     */
382    audio_io_handle_t (*open_output_on_module)(void *service,
383                                     audio_module_handle_t module,
384                                     audio_devices_t *pDevices,
385                                     uint32_t *pSamplingRate,
386                                     audio_format_t *pFormat,
387                                     audio_channel_mask_t *pChannelMask,
388                                     uint32_t *pLatencyMs,
389                                     audio_output_flags_t flags);
390
391    /* Opens an audio input on a particular HW module.
392     *
393     * Same as open_input() but specifying a specific HW module on which the input must be opened.
394     * Also removed deprecated acoustics parameter
395     */
396    audio_io_handle_t (*open_input_on_module)(void *service,
397                                    audio_module_handle_t module,
398                                    audio_devices_t *pDevices,
399                                    uint32_t *pSamplingRate,
400                                    audio_format_t *pFormat,
401                                    audio_channel_mask_t *pChannelMask);
402
403};
404
405/**********************************************************************/
406
407/**
408 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
409 * and the fields of this data structure must begin with hw_module_t
410 * followed by module specific information.
411 */
412typedef struct audio_policy_module {
413    struct hw_module_t common;
414} audio_policy_module_t;
415
416struct audio_policy_device {
417    struct hw_device_t common;
418
419    int (*create_audio_policy)(const struct audio_policy_device *device,
420                               struct audio_policy_service_ops *aps_ops,
421                               void *service,
422                               struct audio_policy **ap);
423
424    int (*destroy_audio_policy)(const struct audio_policy_device *device,
425                                struct audio_policy *ap);
426};
427
428/** convenience API for opening and closing a supported device */
429
430static inline int audio_policy_dev_open(const hw_module_t* module,
431                                    struct audio_policy_device** device)
432{
433    return module->methods->open(module, AUDIO_POLICY_INTERFACE,
434                                 (hw_device_t**)device);
435}
436
437static inline int audio_policy_dev_close(struct audio_policy_device* device)
438{
439    return device->common.close(&device->common);
440}
441
442
443__END_DECLS
444
445#endif  // ANDROID_AUDIO_POLICY_INTERFACE_H
446