Camera: HIDLized camera HALs, first set

* Common camera definitions (camera.common/1.0)
  * Basic status codes, shared types
* Provider 2.4 API (camera.provider/2.4), including vendor tag APIs
  * Enumerate and acquire camera device instances
  * Mostly equivalent to legacy camera module v2.4.
* Device 1.0 API (camera.device/1.0)
  * Mostly equivalent to legacy camera HAL v1.0.
* Device 3.2 API (camera.device/3.2)
  * Mostly equivalent to legacy camera HAL v3.2.
* Metadata 3.2 API (camera.metadata/3.2)
  * Definitions for valid metadata fields for device 3.2

Only the key initial interfaces are added; default implementations are
in a later CL. Other interfaces that will likely need to be added:

* Other provider minor versions
* Other device 3.x minor versions

Test: make -j32
Bug: 30985004
Bug: 32991603
Change-Id: I1c6a9a269bf45276055707bbc58cfc50d29fa919
diff --git a/camera/device/3.2/ICameraDeviceSession.hal b/camera/device/3.2/ICameraDeviceSession.hal
new file mode 100644
index 0000000..c8cc246
--- /dev/null
+++ b/camera/device/3.2/ICameraDeviceSession.hal
@@ -0,0 +1,360 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.camera.device@3.2;
+
+import android.hardware.camera.common@1.0::types;
+
+/**
+ * Camera device active session interface.
+ *
+ * Obtained via ICameraDevice::open(), this interface contains the methods to
+ * configure and request captures from an active camera device.
+ *
+ */
+interface ICameraDeviceSession {
+
+    /**
+     * constructDefaultRequestSettings:
+     *
+     * Create capture settings for standard camera use cases.
+     *
+     * The device must return a settings buffer that is configured to meet the
+     * requested use case, which must be one of the CAMERA3_TEMPLATE_*
+     * enums. All request control fields must be included.
+     *
+     * Performance requirements:
+     *
+     * This must be a non-blocking call. The HAL should return from this call
+     * in 1ms, and must return from this call in 5ms.
+     *
+     * Return values:
+     * @return status Status code for the operation, one of:
+     *     OK:
+     *         On a successful construction of default settings.
+     *     INTERNAL_ERROR:
+     *         An unexpected internal error occurred, and the default settings
+     *         are not available.
+     *     CAMERA_DISCONNECTED:
+     *         An external camera device has been disconnected, and is no longer
+     *         available. This camera device interface is now stale, and a new
+     *         instance must be acquired if the device is reconnected. All
+     *         subsequent calls on this interface must return
+     *         CAMERA_DISCONNECTED.
+     * @return template The default capture request settings for the requested
+     *     use case, or an empty metadata structure if status is not OK.
+     *
+     */
+    constructDefaultRequestSettings(RequestTemplate type) generates
+            (Status status, CameraMetadata requestTemplate);
+
+    /**
+     * configureStreams:
+     *
+     * Reset the HAL camera device processing pipeline and set up new input and
+     * output streams. This call replaces any existing stream configuration with
+     * the streams defined in the streamList. This method must be called at
+     * least once before a request is submitted with processCaptureRequest().
+     *
+     * The streamList must contain at least one output-capable stream, and may
+     * not contain more than one input-capable stream.
+     *
+     * The streamList may contain streams that are also in the currently-active
+     * set of streams (from the previous call to configureStreams()). These
+     * streams must already have valid values for usage, maxBuffers, and the
+     * private pointer.
+     *
+     * If the HAL needs to change the stream configuration for an existing
+     * stream due to the new configuration, it may rewrite the values of usage
+     * and/or maxBuffers during the configure call.
+     *
+     * The framework must detect such a change, and may then reallocate the
+     * stream buffers before using buffers from that stream in a request.
+     *
+     * If a currently-active stream is not included in streamList, the HAL may
+     * safely remove any references to that stream. It must not be reused in a
+     * later configureStreams() call by the framework, and all the gralloc
+     * buffers for it must be freed after the configureStreams() call returns.
+     *
+     * If the stream is new, the maxBuffer field of the stream structure must be
+     * set to 0. The usage must be set to the consumer usage flags. The HAL
+     * device must set these fields in the configureStreams() return values.
+     * These fields are then used by the framework and the platform gralloc
+     * module to allocate the gralloc buffers for each stream.
+     *
+     * Newly allocated buffers may be included in a capture request at any time
+     * by the framework. Once a gralloc buffer is returned to the framework
+     * with processCaptureResult (and its respective releaseFence has been
+     * signaled) the framework may free or reuse it at any time.
+     *
+     * ------------------------------------------------------------------------
+     *
+     * Preconditions:
+     *
+     * The framework must only call this method when no captures are being
+     * processed. That is, all results have been returned to the framework, and
+     * all in-flight input and output buffers have been returned and their
+     * release sync fences have been signaled by the HAL. The framework must not
+     * submit new requests for capture while the configureStreams() call is
+     * underway.
+     *
+     * Postconditions:
+     *
+     * The HAL device must configure itself to provide maximum possible output
+     * frame rate given the sizes and formats of the output streams, as
+     * documented in the camera device's static metadata.
+     *
+     * Performance requirements:
+     *
+     * This call is expected to be heavyweight and possibly take several hundred
+     * milliseconds to complete, since it may require resetting and
+     * reconfiguring the image sensor and the camera processing pipeline.
+     * Nevertheless, the HAL device should attempt to minimize the
+     * reconfiguration delay to minimize the user-visible pauses during
+     * application operational mode changes (such as switching from still
+     * capture to video recording).
+     *
+     * The HAL should return from this call in 500ms, and must return from this
+     * call in 1000ms.
+     *
+     * @return Status Status code for the operation, one of:
+     *     OK:
+     *          On successful stream configuration.
+     *     INTERNAL_ERROR:
+     *         If there has been a fatal error and the device is no longer
+     *         operational. Only close() can be called successfully by the
+     *         framework after this error is returned.
+     *     ILLEGAL_ARGUMENT:
+     *         If the requested stream configuration is invalid. Some examples
+     *         of invalid stream configurations include:
+     *           - Including more than 1 INPUT stream
+     *           - Not including any OUTPUT streams
+     *           - Including streams with unsupported formats, or an unsupported
+     *             size for that format.
+     *           - Including too many output streams of a certain format.
+     *           - Unsupported rotation configuration
+     *           - Stream sizes/formats don't satisfy the
+     *             camera3_stream_configuration_t->operation_mode requirements
+     *             for non-NORMAL mode, or the requested operation_mode is not
+     *             supported by the HAL.
+     *         The camera service cannot filter out all possible illegal stream
+     *         configurations, since some devices may support more simultaneous
+     *         streams or larger stream resolutions than the minimum required
+     *         for a given camera device hardware level. The HAL must return an
+     *         ILLEGAL_ARGUMENT for any unsupported stream set, and then be
+     *         ready to accept a future valid stream configuration in a later
+     *         configureStreams call.
+     * @return finalConfiguration The stream parameters desired by the HAL for
+     *     each stream, including maximum buffers, the usage flags, and the
+     *     override format.
+     *
+     */
+    configureStreams(StreamConfiguration requestedConfiguration)
+            generates (Status status,
+                    HalStreamConfiguration halConfiguration);
+
+    /**
+     * processCaptureRequest:
+     *
+     * Send a new capture request to the HAL. The HAL must not return from
+     * this call until it is ready to accept the next request to process. Only
+     * one call to processCaptureRequest() must be made at a time by the
+     * framework, and the calls must all be from the same thread. The next call
+     * to processCaptureRequest() must be made as soon as a new request and
+     * its associated buffers are available. In a normal preview scenario, this
+     * means the function is generally called again by the framework almost
+     * instantly.
+     *
+     * The actual request processing is asynchronous, with the results of
+     * capture being returned by the HAL through the processCaptureResult()
+     * call. This call requires the result metadata to be available, but output
+     * buffers may simply provide sync fences to wait on. Multiple requests are
+     * expected to be in flight at once, to maintain full output frame rate.
+     *
+     * The framework retains ownership of the request structure. It is only
+     * guaranteed to be valid during this call. The HAL device must make copies
+     * of the information it needs to retain for the capture processing. The HAL
+     * is responsible for waiting on and closing the buffers' fences and
+     * returning the buffer handles to the framework.
+     *
+     * The HAL must write the file descriptor for the input buffer's release
+     * sync fence into input_buffer->release_fence, if input_buffer is not
+     * valid. If the HAL returns -1 for the input buffer release sync fence, the
+     * framework is free to immediately reuse the input buffer. Otherwise, the
+     * framework must wait on the sync fence before refilling and reusing the
+     * input buffer.
+     *
+     * The input/output buffers provided by the framework in each request
+     * may be brand new (having never before seen by the HAL).
+     *
+     * ------------------------------------------------------------------------
+     * Performance considerations:
+     *
+     * Handling a new buffer should be extremely lightweight and there must be
+     * no frame rate degradation or frame jitter introduced.
+     *
+     * This call must return fast enough to ensure that the requested frame
+     * rate can be sustained, especially for streaming cases (post-processing
+     * quality settings set to FAST). The HAL should return this call in 1
+     * frame interval, and must return from this call in 4 frame intervals.
+     *
+     * @return status Status code for the operation, one of:
+     *     OK:
+     *         On a successful start to processing the capture request
+     *     ILLEGAL_ARGUMENT:
+     *         If the input is malformed (the settings are empty when not
+     *         allowed, there are 0 output buffers, etc) and capture processing
+     *         cannot start. Failures during request processing must be
+     *         handled by calling ICameraDeviceCallback::notify(). In case of
+     *         this error, the framework retains responsibility for the
+     *         stream buffers' fences and the buffer handles; the HAL must not
+     *         close the fences or return these buffers with
+     *         ICameraDeviceCallback::processCaptureResult().
+     *     INTERNAL_ERROR:
+     *         If the camera device has encountered a serious error. After this
+     *         error is returned, only the close() method can be successfully
+     *         called by the framework.
+     *
+     */
+    processCaptureRequest(CaptureRequest request)
+            generates (Status status);
+
+    /**
+     * flush:
+     *
+     * Flush all currently in-process captures and all buffers in the pipeline
+     * on the given device. Generally, this method is used to dump all state as
+     * quickly as possible in order to prepare for a configure_streams() call.
+     *
+     * No buffers are required to be successfully returned, so every buffer
+     * held at the time of flush() (whether successfully filled or not) may be
+     * returned with CAMERA3_BUFFER_STATUS_ERROR. Note the HAL is still allowed
+     * to return valid (CAMERA3_BUFFER_STATUS_OK) buffers during this call,
+     * provided they are successfully filled.
+     *
+     * All requests currently in the HAL are expected to be returned as soon as
+     * possible. Not-in-process requests must return errors immediately. Any
+     * interruptible hardware blocks must be stopped, and any uninterruptible
+     * blocks must be waited on.
+     *
+     * flush() may be called concurrently to processCaptureRequest(), with the
+     * expectation that processCaptureRequest returns quickly and the
+     * request submitted in that processCaptureRequest call is treated like
+     * all other in-flight requests. Due to concurrency issues, it is possible
+     * that from the HAL's point of view, a processCaptureRequest() call may
+     * be started after flush has been invoked but has not returned yet. If such
+     * a call happens before flush() returns, the HAL must treat the new
+     * capture request like other in-flight pending requests (see #4 below).
+     *
+     * More specifically, the HAL must follow below requirements for various
+     * cases:
+     *
+     * 1. For captures that are too late for the HAL to cancel/stop, and must be
+     *    completed normally by the HAL; i.e. the HAL can send shutter/notify
+     *    and processCaptureResult and buffers as normal.
+     *
+     * 2. For pending requests that have not done any processing, the HAL must
+     *    call notify CAMERA3_MSG_ERROR_REQUEST, and return all the output
+     *    buffers with processCaptureResult in the error state
+     *    (CAMERA3_BUFFER_STATUS_ERROR). The HAL must not place the release
+     *    fence into an error state, instead, the release fences must be set to
+     *    the acquire fences passed by the framework, or -1 if they have been
+     *    waited on by the HAL already. This is also the path to follow for any
+     *    captures for which the HAL already called notify() with
+     *    CAMERA3_MSG_SHUTTER but won't be producing any metadata/valid buffers
+     *    for. After CAMERA3_MSG_ERROR_REQUEST, for a given frame, only
+     *    processCaptureResults with buffers in CAMERA3_BUFFER_STATUS_ERROR
+     *    are allowed. No further notifys or processCaptureResult with
+     *    non-empty metadata is allowed.
+     *
+     * 3. For partially completed pending requests that do not have all the
+     *    output buffers or perhaps missing metadata, the HAL must follow
+     *    below:
+     *
+     *    3.1. Call notify with CAMERA3_MSG_ERROR_RESULT if some of the expected
+     *         result metadata (i.e. one or more partial metadata) won't be
+     *         available for the capture.
+     *
+     *    3.2. Call notify with CAMERA3_MSG_ERROR_BUFFER for every buffer that
+     *         won't be produced for the capture.
+     *
+     *    3.3. Call notify with CAMERA3_MSG_SHUTTER with the capture timestamp
+     *         before any buffers/metadata are returned with
+     *         processCaptureResult.
+     *
+     *    3.4. For captures that will produce some results, the HAL must not
+     *         call CAMERA3_MSG_ERROR_REQUEST, since that indicates complete
+     *         failure.
+     *
+     *    3.5. Valid buffers/metadata must be passed to the framework as
+     *         normal.
+     *
+     *    3.6. Failed buffers must be returned to the framework as described
+     *         for case 2. But failed buffers do not have to follow the strict
+     *         ordering valid buffers do, and may be out-of-order with respect
+     *         to valid buffers. For example, if buffers A, B, C, D, E are sent,
+     *         D and E are failed, then A, E, B, D, C is an acceptable return
+     *         order.
+     *
+     *    3.7. For fully-missing metadata, calling CAMERA3_MSG_ERROR_RESULT is
+     *         sufficient, no need to call processCaptureResult with empty
+     *         metadata or equivalent.
+     *
+     * 4. If a flush() is invoked while a processCaptureRequest() invocation
+     *    is active, that process call must return as soon as possible. In
+     *    addition, if a processCaptureRequest() call is made after flush()
+     *    has been invoked but before flush() has returned, the capture request
+     *    provided by the late processCaptureRequest call must be treated
+     *    like a pending request in case #2 above.
+     *
+     * flush() must only return when there are no more outstanding buffers or
+     * requests left in the HAL. The framework may call configure_streams (as
+     * the HAL state is now quiesced) or may issue new requests.
+     *
+     * Note that it's sufficient to only support fully-succeeded and
+     * fully-failed result cases. However, it is highly desirable to support
+     * the partial failure cases as well, as it could help improve the flush
+     * call overall performance.
+     *
+     * Performance requirements:
+     *
+     * The HAL should return from this call in 100ms, and must return from this
+     * call in 1000ms. And this call must not be blocked longer than pipeline
+     * latency (see S7 for definition).
+     *
+     * @return status Status code for the operation, one of:
+     *     OK:
+     *         On a successful flush of the camera HAL.
+     *     INTERNAL_ERROR:
+     *         If the camera device has encountered a serious error. After this
+     *         error is returned, only the close() method can be successfully
+     *         called by the framework.
+     */
+    flush() generates (Status status);
+
+    /**
+     * close:
+     *
+     * Shut down the camera device.
+     *
+     * After this call, all calls to this session instance must return
+     * INTERNAL_ERROR.
+     *
+     * This method must always succeed, even if the device has encountered a
+     * serious error.
+     */
+    close();
+};