xref: /aosp_15_r20/hardware/interfaces/audio/2.0/IStream.hal (revision 4d7e907c777eeecc4c5bd7cf640a754fac206ff7)
1*4d7e907cSAndroid Build Coastguard Worker/*
2*4d7e907cSAndroid Build Coastguard Worker * Copyright (C) 2016 The Android Open Source Project
3*4d7e907cSAndroid Build Coastguard Worker *
4*4d7e907cSAndroid Build Coastguard Worker * Licensed under the Apache License, Version 2.0 (the "License");
5*4d7e907cSAndroid Build Coastguard Worker * you may not use this file except in compliance with the License.
6*4d7e907cSAndroid Build Coastguard Worker * You may obtain a copy of the License at
7*4d7e907cSAndroid Build Coastguard Worker *
8*4d7e907cSAndroid Build Coastguard Worker *      http://www.apache.org/licenses/LICENSE-2.0
9*4d7e907cSAndroid Build Coastguard Worker *
10*4d7e907cSAndroid Build Coastguard Worker * Unless required by applicable law or agreed to in writing, software
11*4d7e907cSAndroid Build Coastguard Worker * distributed under the License is distributed on an "AS IS" BASIS,
12*4d7e907cSAndroid Build Coastguard Worker * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13*4d7e907cSAndroid Build Coastguard Worker * See the License for the specific language governing permissions and
14*4d7e907cSAndroid Build Coastguard Worker * limitations under the License.
15*4d7e907cSAndroid Build Coastguard Worker */
16*4d7e907cSAndroid Build Coastguard Worker
17*4d7e907cSAndroid Build Coastguard Workerpackage [email protected];
18*4d7e907cSAndroid Build Coastguard Worker
19*4d7e907cSAndroid Build Coastguard Workerimport [email protected];
20*4d7e907cSAndroid Build Coastguard Workerimport [email protected]::IEffect;
21*4d7e907cSAndroid Build Coastguard Worker
22*4d7e907cSAndroid Build Coastguard Workerinterface IStream {
23*4d7e907cSAndroid Build Coastguard Worker    typedef [email protected]::Result Result;
24*4d7e907cSAndroid Build Coastguard Worker
25*4d7e907cSAndroid Build Coastguard Worker    /**
26*4d7e907cSAndroid Build Coastguard Worker     * Return the frame size (number of bytes per sample).
27*4d7e907cSAndroid Build Coastguard Worker     *
28*4d7e907cSAndroid Build Coastguard Worker     * @return frameSize frame size in bytes.
29*4d7e907cSAndroid Build Coastguard Worker     */
30*4d7e907cSAndroid Build Coastguard Worker    getFrameSize() generates (uint64_t frameSize);
31*4d7e907cSAndroid Build Coastguard Worker
32*4d7e907cSAndroid Build Coastguard Worker    /**
33*4d7e907cSAndroid Build Coastguard Worker     * Return the frame count of the buffer. Calling this method is equivalent
34*4d7e907cSAndroid Build Coastguard Worker     * to getting AUDIO_PARAMETER_STREAM_FRAME_COUNT on the legacy HAL.
35*4d7e907cSAndroid Build Coastguard Worker     *
36*4d7e907cSAndroid Build Coastguard Worker     * @return count frame count.
37*4d7e907cSAndroid Build Coastguard Worker     */
38*4d7e907cSAndroid Build Coastguard Worker    getFrameCount() generates (uint64_t count);
39*4d7e907cSAndroid Build Coastguard Worker
40*4d7e907cSAndroid Build Coastguard Worker    /**
41*4d7e907cSAndroid Build Coastguard Worker     * Return the size of input/output buffer in bytes for this stream.
42*4d7e907cSAndroid Build Coastguard Worker     * It must be a multiple of the frame size.
43*4d7e907cSAndroid Build Coastguard Worker     *
44*4d7e907cSAndroid Build Coastguard Worker     * @return buffer buffer size in bytes.
45*4d7e907cSAndroid Build Coastguard Worker     */
46*4d7e907cSAndroid Build Coastguard Worker    getBufferSize() generates (uint64_t bufferSize);
47*4d7e907cSAndroid Build Coastguard Worker
48*4d7e907cSAndroid Build Coastguard Worker    /**
49*4d7e907cSAndroid Build Coastguard Worker     * Return the sampling rate in Hz.
50*4d7e907cSAndroid Build Coastguard Worker     *
51*4d7e907cSAndroid Build Coastguard Worker     * @return sampleRateHz sample rate in Hz.
52*4d7e907cSAndroid Build Coastguard Worker     */
53*4d7e907cSAndroid Build Coastguard Worker    getSampleRate() generates (uint32_t sampleRateHz);
54*4d7e907cSAndroid Build Coastguard Worker
55*4d7e907cSAndroid Build Coastguard Worker    /**
56*4d7e907cSAndroid Build Coastguard Worker     * Return supported sampling rates of the stream. Calling this method is
57*4d7e907cSAndroid Build Coastguard Worker     * equivalent to getting AUDIO_PARAMETER_STREAM_SUP_SAMPLING_RATES on the
58*4d7e907cSAndroid Build Coastguard Worker     * legacy HAL.
59*4d7e907cSAndroid Build Coastguard Worker     *
60*4d7e907cSAndroid Build Coastguard Worker     * @return sampleRateHz supported sample rates.
61*4d7e907cSAndroid Build Coastguard Worker     */
62*4d7e907cSAndroid Build Coastguard Worker    getSupportedSampleRates() generates (vec<uint32_t> sampleRates);
63*4d7e907cSAndroid Build Coastguard Worker
64*4d7e907cSAndroid Build Coastguard Worker    /**
65*4d7e907cSAndroid Build Coastguard Worker     * Sets the sampling rate of the stream. Calling this method is equivalent
66*4d7e907cSAndroid Build Coastguard Worker     * to setting AUDIO_PARAMETER_STREAM_SAMPLING_RATE on the legacy HAL.
67*4d7e907cSAndroid Build Coastguard Worker     *
68*4d7e907cSAndroid Build Coastguard Worker     * @param sampleRateHz sample rate in Hz.
69*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
70*4d7e907cSAndroid Build Coastguard Worker     */
71*4d7e907cSAndroid Build Coastguard Worker    setSampleRate(uint32_t sampleRateHz) generates (Result retval);
72*4d7e907cSAndroid Build Coastguard Worker
73*4d7e907cSAndroid Build Coastguard Worker    /**
74*4d7e907cSAndroid Build Coastguard Worker     * Return the channel mask of the stream.
75*4d7e907cSAndroid Build Coastguard Worker     *
76*4d7e907cSAndroid Build Coastguard Worker     * @return mask channel mask.
77*4d7e907cSAndroid Build Coastguard Worker     */
78*4d7e907cSAndroid Build Coastguard Worker    getChannelMask() generates (AudioChannelMask mask);
79*4d7e907cSAndroid Build Coastguard Worker
80*4d7e907cSAndroid Build Coastguard Worker    /**
81*4d7e907cSAndroid Build Coastguard Worker     * Return supported channel masks of the stream. Calling this method is
82*4d7e907cSAndroid Build Coastguard Worker     * equivalent to getting AUDIO_PARAMETER_STREAM_SUP_CHANNELS on the legacy
83*4d7e907cSAndroid Build Coastguard Worker     * HAL.
84*4d7e907cSAndroid Build Coastguard Worker     *
85*4d7e907cSAndroid Build Coastguard Worker     * @return masks supported audio masks.
86*4d7e907cSAndroid Build Coastguard Worker     */
87*4d7e907cSAndroid Build Coastguard Worker    getSupportedChannelMasks() generates (vec<AudioChannelMask> masks);
88*4d7e907cSAndroid Build Coastguard Worker
89*4d7e907cSAndroid Build Coastguard Worker    /**
90*4d7e907cSAndroid Build Coastguard Worker     * Sets the channel mask of the stream. Calling this method is equivalent to
91*4d7e907cSAndroid Build Coastguard Worker     * setting AUDIO_PARAMETER_STREAM_CHANNELS on the legacy HAL.
92*4d7e907cSAndroid Build Coastguard Worker     *
93*4d7e907cSAndroid Build Coastguard Worker     * @param format audio format.
94*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
95*4d7e907cSAndroid Build Coastguard Worker     */
96*4d7e907cSAndroid Build Coastguard Worker    setChannelMask(AudioChannelMask mask) generates (Result retval);
97*4d7e907cSAndroid Build Coastguard Worker
98*4d7e907cSAndroid Build Coastguard Worker    /**
99*4d7e907cSAndroid Build Coastguard Worker     * Return the audio format of the stream.
100*4d7e907cSAndroid Build Coastguard Worker     *
101*4d7e907cSAndroid Build Coastguard Worker     * @return format audio format.
102*4d7e907cSAndroid Build Coastguard Worker     */
103*4d7e907cSAndroid Build Coastguard Worker    getFormat() generates (AudioFormat format);
104*4d7e907cSAndroid Build Coastguard Worker
105*4d7e907cSAndroid Build Coastguard Worker    /**
106*4d7e907cSAndroid Build Coastguard Worker     * Return supported audio formats of the stream. Calling this method is
107*4d7e907cSAndroid Build Coastguard Worker     * equivalent to getting AUDIO_PARAMETER_STREAM_SUP_FORMATS on the legacy
108*4d7e907cSAndroid Build Coastguard Worker     * HAL.
109*4d7e907cSAndroid Build Coastguard Worker     *
110*4d7e907cSAndroid Build Coastguard Worker     * @return formats supported audio formats.
111*4d7e907cSAndroid Build Coastguard Worker     */
112*4d7e907cSAndroid Build Coastguard Worker    getSupportedFormats() generates (vec<AudioFormat> formats);
113*4d7e907cSAndroid Build Coastguard Worker
114*4d7e907cSAndroid Build Coastguard Worker    /**
115*4d7e907cSAndroid Build Coastguard Worker     * Sets the audio format of the stream. Calling this method is equivalent to
116*4d7e907cSAndroid Build Coastguard Worker     * setting AUDIO_PARAMETER_STREAM_FORMAT on the legacy HAL.
117*4d7e907cSAndroid Build Coastguard Worker     *
118*4d7e907cSAndroid Build Coastguard Worker     * @param format audio format.
119*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
120*4d7e907cSAndroid Build Coastguard Worker     */
121*4d7e907cSAndroid Build Coastguard Worker    setFormat(AudioFormat format) generates (Result retval);
122*4d7e907cSAndroid Build Coastguard Worker
123*4d7e907cSAndroid Build Coastguard Worker    /**
124*4d7e907cSAndroid Build Coastguard Worker     * Convenience method for retrieving several stream parameters in
125*4d7e907cSAndroid Build Coastguard Worker     * one transaction.
126*4d7e907cSAndroid Build Coastguard Worker     *
127*4d7e907cSAndroid Build Coastguard Worker     * @return sampleRateHz sample rate in Hz.
128*4d7e907cSAndroid Build Coastguard Worker     * @return mask channel mask.
129*4d7e907cSAndroid Build Coastguard Worker     * @return format audio format.
130*4d7e907cSAndroid Build Coastguard Worker     */
131*4d7e907cSAndroid Build Coastguard Worker    getAudioProperties() generates (
132*4d7e907cSAndroid Build Coastguard Worker            uint32_t sampleRateHz, AudioChannelMask mask, AudioFormat format);
133*4d7e907cSAndroid Build Coastguard Worker
134*4d7e907cSAndroid Build Coastguard Worker    /**
135*4d7e907cSAndroid Build Coastguard Worker     * Applies audio effect to the stream.
136*4d7e907cSAndroid Build Coastguard Worker     *
137*4d7e907cSAndroid Build Coastguard Worker     * @param effectId effect ID (obtained from IEffectsFactory.createEffect) of
138*4d7e907cSAndroid Build Coastguard Worker     *                 the effect to apply.
139*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
140*4d7e907cSAndroid Build Coastguard Worker     */
141*4d7e907cSAndroid Build Coastguard Worker    addEffect(uint64_t effectId) generates (Result retval);
142*4d7e907cSAndroid Build Coastguard Worker
143*4d7e907cSAndroid Build Coastguard Worker    /**
144*4d7e907cSAndroid Build Coastguard Worker     * Stops application of the effect to the stream.
145*4d7e907cSAndroid Build Coastguard Worker     *
146*4d7e907cSAndroid Build Coastguard Worker     * @param effectId effect ID (obtained from IEffectsFactory.createEffect) of
147*4d7e907cSAndroid Build Coastguard Worker     *                 the effect to remove.
148*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
149*4d7e907cSAndroid Build Coastguard Worker     */
150*4d7e907cSAndroid Build Coastguard Worker    removeEffect(uint64_t effectId) generates (Result retval);
151*4d7e907cSAndroid Build Coastguard Worker
152*4d7e907cSAndroid Build Coastguard Worker    /**
153*4d7e907cSAndroid Build Coastguard Worker     * Put the audio hardware input/output into standby mode.
154*4d7e907cSAndroid Build Coastguard Worker     * Driver must exit from standby mode at the next I/O operation.
155*4d7e907cSAndroid Build Coastguard Worker     *
156*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
157*4d7e907cSAndroid Build Coastguard Worker     */
158*4d7e907cSAndroid Build Coastguard Worker    standby() generates (Result retval);
159*4d7e907cSAndroid Build Coastguard Worker
160*4d7e907cSAndroid Build Coastguard Worker    /**
161*4d7e907cSAndroid Build Coastguard Worker     * Return the set of device(s) which this stream is connected to.
162*4d7e907cSAndroid Build Coastguard Worker     *
163*4d7e907cSAndroid Build Coastguard Worker     * @return device set of device(s) which this stream is connected to.
164*4d7e907cSAndroid Build Coastguard Worker     */
165*4d7e907cSAndroid Build Coastguard Worker    getDevice() generates (AudioDevice device);
166*4d7e907cSAndroid Build Coastguard Worker
167*4d7e907cSAndroid Build Coastguard Worker    /**
168*4d7e907cSAndroid Build Coastguard Worker     * Connects the stream to the device.
169*4d7e907cSAndroid Build Coastguard Worker     *
170*4d7e907cSAndroid Build Coastguard Worker     * This method must only be used for HALs that do not support
171*4d7e907cSAndroid Build Coastguard Worker     * 'IDevice.createAudioPatch' method. Calling this method is
172*4d7e907cSAndroid Build Coastguard Worker     * equivalent to setting AUDIO_PARAMETER_STREAM_ROUTING in the legacy HAL
173*4d7e907cSAndroid Build Coastguard Worker     * interface.
174*4d7e907cSAndroid Build Coastguard Worker     *
175*4d7e907cSAndroid Build Coastguard Worker     * @param address device to connect the stream to.
176*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
177*4d7e907cSAndroid Build Coastguard Worker     */
178*4d7e907cSAndroid Build Coastguard Worker    setDevice(DeviceAddress address) generates (Result retval);
179*4d7e907cSAndroid Build Coastguard Worker
180*4d7e907cSAndroid Build Coastguard Worker    /**
181*4d7e907cSAndroid Build Coastguard Worker     * Notifies the stream about device connection state. Calling this method is
182*4d7e907cSAndroid Build Coastguard Worker     * equivalent to setting AUDIO_PARAMETER_DEVICE_[DIS]CONNECT on the legacy
183*4d7e907cSAndroid Build Coastguard Worker     * HAL.
184*4d7e907cSAndroid Build Coastguard Worker     *
185*4d7e907cSAndroid Build Coastguard Worker     * @param address audio device specification.
186*4d7e907cSAndroid Build Coastguard Worker     * @param connected whether the device is connected.
187*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
188*4d7e907cSAndroid Build Coastguard Worker     */
189*4d7e907cSAndroid Build Coastguard Worker    setConnectedState(DeviceAddress address, bool connected)
190*4d7e907cSAndroid Build Coastguard Worker            generates (Result retval);
191*4d7e907cSAndroid Build Coastguard Worker
192*4d7e907cSAndroid Build Coastguard Worker    /**
193*4d7e907cSAndroid Build Coastguard Worker     * Sets the HW synchronization source. Calling this method is equivalent to
194*4d7e907cSAndroid Build Coastguard Worker     * setting AUDIO_PARAMETER_STREAM_HW_AV_SYNC on the legacy HAL.
195*4d7e907cSAndroid Build Coastguard Worker     *
196*4d7e907cSAndroid Build Coastguard Worker     * @param hwAvSync HW synchronization source
197*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
198*4d7e907cSAndroid Build Coastguard Worker     */
199*4d7e907cSAndroid Build Coastguard Worker    setHwAvSync(AudioHwSync hwAvSync) generates (Result retval);
200*4d7e907cSAndroid Build Coastguard Worker
201*4d7e907cSAndroid Build Coastguard Worker    /**
202*4d7e907cSAndroid Build Coastguard Worker     * Generic method for retrieving vendor-specific parameter values.
203*4d7e907cSAndroid Build Coastguard Worker     * The framework does not interpret the parameters, they are passed
204*4d7e907cSAndroid Build Coastguard Worker     * in an opaque manner between a vendor application and HAL.
205*4d7e907cSAndroid Build Coastguard Worker     *
206*4d7e907cSAndroid Build Coastguard Worker     * @param keys parameter keys.
207*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
208*4d7e907cSAndroid Build Coastguard Worker     * @return parameters parameter key value pairs.
209*4d7e907cSAndroid Build Coastguard Worker     */
210*4d7e907cSAndroid Build Coastguard Worker    getParameters(vec<string> keys)
211*4d7e907cSAndroid Build Coastguard Worker            generates (Result retval, vec<ParameterValue> parameters);
212*4d7e907cSAndroid Build Coastguard Worker
213*4d7e907cSAndroid Build Coastguard Worker    /**
214*4d7e907cSAndroid Build Coastguard Worker     * Generic method for setting vendor-specific parameter values.
215*4d7e907cSAndroid Build Coastguard Worker     * The framework does not interpret the parameters, they are passed
216*4d7e907cSAndroid Build Coastguard Worker     * in an opaque manner between a vendor application and HAL.
217*4d7e907cSAndroid Build Coastguard Worker     *
218*4d7e907cSAndroid Build Coastguard Worker     * @param parameters parameter key value pairs.
219*4d7e907cSAndroid Build Coastguard Worker     * @return retval operation completion status.
220*4d7e907cSAndroid Build Coastguard Worker     */
221*4d7e907cSAndroid Build Coastguard Worker    setParameters(vec<ParameterValue> parameters) generates (Result retval);
222*4d7e907cSAndroid Build Coastguard Worker
223*4d7e907cSAndroid Build Coastguard Worker    /**
224*4d7e907cSAndroid Build Coastguard Worker     * Dumps information about the stream into the provided file descriptor.
225*4d7e907cSAndroid Build Coastguard Worker     * This is used for the dumpsys facility.
226*4d7e907cSAndroid Build Coastguard Worker     *
227*4d7e907cSAndroid Build Coastguard Worker     * @param fd dump file descriptor.
228*4d7e907cSAndroid Build Coastguard Worker     */
229*4d7e907cSAndroid Build Coastguard Worker    debugDump(handle fd);
230*4d7e907cSAndroid Build Coastguard Worker
231*4d7e907cSAndroid Build Coastguard Worker    /**
232*4d7e907cSAndroid Build Coastguard Worker     * Called by the framework to start a stream operating in mmap mode.
233*4d7e907cSAndroid Build Coastguard Worker     * createMmapBuffer() must be called before calling start().
234*4d7e907cSAndroid Build Coastguard Worker     * Function only implemented by streams operating in mmap mode.
235*4d7e907cSAndroid Build Coastguard Worker     *
236*4d7e907cSAndroid Build Coastguard Worker     * @return retval OK in case the success.
237*4d7e907cSAndroid Build Coastguard Worker     *                NOT_SUPPORTED on non mmap mode streams
238*4d7e907cSAndroid Build Coastguard Worker     *                INVALID_STATE if called out of sequence
239*4d7e907cSAndroid Build Coastguard Worker     */
240*4d7e907cSAndroid Build Coastguard Worker    start() generates (Result retval);
241*4d7e907cSAndroid Build Coastguard Worker
242*4d7e907cSAndroid Build Coastguard Worker    /**
243*4d7e907cSAndroid Build Coastguard Worker     * Called by the framework to stop a stream operating in mmap mode.
244*4d7e907cSAndroid Build Coastguard Worker     * Function only implemented by streams operating in mmap mode.
245*4d7e907cSAndroid Build Coastguard Worker     *
246*4d7e907cSAndroid Build Coastguard Worker     * @return retval OK in case the succes.
247*4d7e907cSAndroid Build Coastguard Worker     *                NOT_SUPPORTED on non mmap mode streams
248*4d7e907cSAndroid Build Coastguard Worker     *                INVALID_STATE if called out of sequence
249*4d7e907cSAndroid Build Coastguard Worker     */
250*4d7e907cSAndroid Build Coastguard Worker    stop() generates (Result retval) ;
251*4d7e907cSAndroid Build Coastguard Worker
252*4d7e907cSAndroid Build Coastguard Worker    /**
253*4d7e907cSAndroid Build Coastguard Worker     * Called by the framework to retrieve information on the mmap buffer used for audio
254*4d7e907cSAndroid Build Coastguard Worker     * samples transfer.
255*4d7e907cSAndroid Build Coastguard Worker     * Function only implemented by streams operating in mmap mode.
256*4d7e907cSAndroid Build Coastguard Worker     *
257*4d7e907cSAndroid Build Coastguard Worker     * @param minSizeFrames minimum buffer size requested. The actual buffer
258*4d7e907cSAndroid Build Coastguard Worker     *                     size returned in struct MmapBufferInfo can be larger.
259*4d7e907cSAndroid Build Coastguard Worker     * @return retval OK in case the success.
260*4d7e907cSAndroid Build Coastguard Worker     *                NOT_SUPPORTED on non mmap mode streams
261*4d7e907cSAndroid Build Coastguard Worker     *                NOT_INITIALIZED in case of memory allocation error
262*4d7e907cSAndroid Build Coastguard Worker     *                INVALID_ARGUMENTS if the requested buffer size is too large
263*4d7e907cSAndroid Build Coastguard Worker     *                INVALID_STATE if called out of sequence
264*4d7e907cSAndroid Build Coastguard Worker     * @return info    a MmapBufferInfo struct containing information on the MMMAP buffer created.
265*4d7e907cSAndroid Build Coastguard Worker     */
266*4d7e907cSAndroid Build Coastguard Worker    createMmapBuffer(int32_t minSizeFrames)
267*4d7e907cSAndroid Build Coastguard Worker            generates (Result retval, MmapBufferInfo info);
268*4d7e907cSAndroid Build Coastguard Worker
269*4d7e907cSAndroid Build Coastguard Worker    /**
270*4d7e907cSAndroid Build Coastguard Worker     * Called by the framework to read current read/write position in the mmap buffer
271*4d7e907cSAndroid Build Coastguard Worker     * with associated time stamp.
272*4d7e907cSAndroid Build Coastguard Worker     * Function only implemented by streams operating in mmap mode.
273*4d7e907cSAndroid Build Coastguard Worker     *
274*4d7e907cSAndroid Build Coastguard Worker     * @return retval OK in case the success.
275*4d7e907cSAndroid Build Coastguard Worker     *                NOT_SUPPORTED on non mmap mode streams
276*4d7e907cSAndroid Build Coastguard Worker     *                INVALID_STATE if called out of sequence
277*4d7e907cSAndroid Build Coastguard Worker     * @return position a MmapPosition struct containing current HW read/write position in frames
278*4d7e907cSAndroid Build Coastguard Worker     *                  with associated time stamp.
279*4d7e907cSAndroid Build Coastguard Worker     */
280*4d7e907cSAndroid Build Coastguard Worker    getMmapPosition()
281*4d7e907cSAndroid Build Coastguard Worker            generates (Result retval, MmapPosition position);
282*4d7e907cSAndroid Build Coastguard Worker
283*4d7e907cSAndroid Build Coastguard Worker    /**
284*4d7e907cSAndroid Build Coastguard Worker     * Called by the framework to deinitialize the stream and free up
285*4d7e907cSAndroid Build Coastguard Worker     * all the currently allocated resources. It is recommended to close
286*4d7e907cSAndroid Build Coastguard Worker     * the stream on the client side as soon as it is becomes unused.
287*4d7e907cSAndroid Build Coastguard Worker     *
288*4d7e907cSAndroid Build Coastguard Worker     * @return retval OK in case the success.
289*4d7e907cSAndroid Build Coastguard Worker     *                NOT_SUPPORTED if called on IStream instead of input or
290*4d7e907cSAndroid Build Coastguard Worker     *                              output stream interface.
291*4d7e907cSAndroid Build Coastguard Worker     *                INVALID_STATE if the stream was already closed.
292*4d7e907cSAndroid Build Coastguard Worker     */
293*4d7e907cSAndroid Build Coastguard Worker    close() generates (Result retval);
294*4d7e907cSAndroid Build Coastguard Worker};
295