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1 /*
2  * Copyright (C) 2012 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 // FIXME: add well-defined names for cameras
18 
19 #ifndef ANDROID_INCLUDE_CAMERA_COMMON_H
20 #define ANDROID_INCLUDE_CAMERA_COMMON_H
21 
22 #include <stdint.h>
23 #include <stdbool.h>
24 #include <sys/cdefs.h>
25 #include <sys/types.h>
26 #include <cutils/native_handle.h>
27 #include <system/camera.h>
28 #include <system/camera_vendor_tags.h>
29 #include <hardware/hardware.h>
30 #include <hardware/gralloc.h>
31 
32 __BEGIN_DECLS
33 
34 /**
35  * The id of this module
36  */
37 #define CAMERA_HARDWARE_MODULE_ID "camera"
38 
39 /**
40  * Module versioning information for the Camera hardware module, based on
41  * camera_module_t.common.module_api_version. The two most significant hex
42  * digits represent the major version, and the two least significant represent
43  * the minor version.
44  *
45  *******************************************************************************
46  * Versions: 0.X - 1.X [CAMERA_MODULE_API_VERSION_1_0]
47  *
48  *   Camera modules that report these version numbers implement the initial
49  *   camera module HAL interface. All camera devices openable through this
50  *   module support only version 1 of the camera device HAL. The device_version
51  *   and static_camera_characteristics fields of camera_info are not valid. Only
52  *   the android.hardware.Camera API can be supported by this module and its
53  *   devices.
54  *
55  *******************************************************************************
56  * Version: 2.0 [CAMERA_MODULE_API_VERSION_2_0]
57  *
58  *   Camera modules that report this version number implement the second version
59  *   of the camera module HAL interface. Camera devices openable through this
60  *   module may support either version 1.0 or version 2.0 of the camera device
61  *   HAL interface. The device_version field of camera_info is always valid; the
62  *   static_camera_characteristics field of camera_info is valid if the
63  *   device_version field is 2.0 or higher.
64  *
65  *******************************************************************************
66  * Version: 2.1 [CAMERA_MODULE_API_VERSION_2_1]
67  *
68  *   This camera module version adds support for asynchronous callbacks to the
69  *   framework from the camera HAL module, which is used to notify the framework
70  *   about changes to the camera module state. Modules that provide a valid
71  *   set_callbacks() method must report at least this version number.
72  *
73  *******************************************************************************
74  * Version: 2.2 [CAMERA_MODULE_API_VERSION_2_2]
75  *
76  *   This camera module version adds vendor tag support from the module, and
77  *   deprecates the old vendor_tag_query_ops that were previously only
78  *   accessible with a device open.
79  *
80  *******************************************************************************
81  * Version: 2.3 [CAMERA_MODULE_API_VERSION_2_3]
82  *
83  *   This camera module version adds open legacy camera HAL device support.
84  *   Framework can use it to open the camera device as lower device HAL version
85  *   HAL device if the same device can support multiple device API versions.
86  *   The standard hardware module open call (common.methods->open) continues
87  *   to open the camera device with the latest supported version, which is
88  *   also the version listed in camera_info_t.device_version.
89  *
90  *******************************************************************************
91  * Version: 2.4 [CAMERA_MODULE_API_VERSION_2_4]
92  *
93  * This camera module version adds below API changes:
94  *
95  * 1. Torch mode support. The framework can use it to turn on torch mode for
96  *    any camera device that has a flash unit, without opening a camera device. The
97  *    camera device has a higher priority accessing the flash unit than the camera
98  *    module; opening a camera device will turn off the torch if it had been enabled
99  *    through the module interface. When there are any resource conflicts, such as
100  *    open() is called to open a camera device, the camera HAL module must notify the
101  *    framework through the torch mode status callback that the torch mode has been
102  *    turned off.
103  *
104  * 2. External camera (e.g. USB hot-plug camera) support. The API updates specify that
105  *    the camera static info is only available when camera is connected and ready to
106  *    use for external hot-plug cameras. Calls to get static info will be invalid
107  *    calls when camera status is not CAMERA_DEVICE_STATUS_PRESENT. The frameworks
108  *    will only count on device status change callbacks to manage the available external
109  *    camera list.
110  *
111  * 3. Camera arbitration hints. This module version adds support for explicitly
112  *    indicating the number of camera devices that can be simultaneously opened and used.
113  *    To specify valid combinations of devices, the resource_cost and conflicting_devices
114  *    fields should always be set in the camera_info structure returned by the
115  *    get_camera_info call.
116  *
117  * 4. Module initialization method. This will be called by the camera service
118  *    right after the HAL module is loaded, to allow for one-time initialization
119  *    of the HAL. It is called before any other module methods are invoked.
120  */
121 
122 /**
123  * Predefined macros for currently-defined version numbers
124  */
125 
126 /**
127  * All module versions <= HARDWARE_MODULE_API_VERSION(1, 0xFF) must be treated
128  * as CAMERA_MODULE_API_VERSION_1_0
129  */
130 #define CAMERA_MODULE_API_VERSION_1_0 HARDWARE_MODULE_API_VERSION(1, 0)
131 #define CAMERA_MODULE_API_VERSION_2_0 HARDWARE_MODULE_API_VERSION(2, 0)
132 #define CAMERA_MODULE_API_VERSION_2_1 HARDWARE_MODULE_API_VERSION(2, 1)
133 #define CAMERA_MODULE_API_VERSION_2_2 HARDWARE_MODULE_API_VERSION(2, 2)
134 #define CAMERA_MODULE_API_VERSION_2_3 HARDWARE_MODULE_API_VERSION(2, 3)
135 #define CAMERA_MODULE_API_VERSION_2_4 HARDWARE_MODULE_API_VERSION(2, 4)
136 
137 #define CAMERA_MODULE_API_VERSION_CURRENT CAMERA_MODULE_API_VERSION_2_4
138 
139 /**
140  * All device versions <= HARDWARE_DEVICE_API_VERSION(1, 0xFF) must be treated
141  * as CAMERA_DEVICE_API_VERSION_1_0
142  */
143 #define CAMERA_DEVICE_API_VERSION_1_0 HARDWARE_DEVICE_API_VERSION(1, 0)
144 #define CAMERA_DEVICE_API_VERSION_2_0 HARDWARE_DEVICE_API_VERSION(2, 0)
145 #define CAMERA_DEVICE_API_VERSION_2_1 HARDWARE_DEVICE_API_VERSION(2, 1)
146 #define CAMERA_DEVICE_API_VERSION_3_0 HARDWARE_DEVICE_API_VERSION(3, 0)
147 #define CAMERA_DEVICE_API_VERSION_3_1 HARDWARE_DEVICE_API_VERSION(3, 1)
148 #define CAMERA_DEVICE_API_VERSION_3_2 HARDWARE_DEVICE_API_VERSION(3, 2)
149 #define CAMERA_DEVICE_API_VERSION_3_3 HARDWARE_DEVICE_API_VERSION(3, 3)
150 
151 // Device version 3.3 is current, older HAL camera device versions are not
152 // recommended for new devices.
153 #define CAMERA_DEVICE_API_VERSION_CURRENT CAMERA_DEVICE_API_VERSION_3_3
154 
155 /**
156  * Defined in /system/media/camera/include/system/camera_metadata.h
157  */
158 typedef struct camera_metadata camera_metadata_t;
159 
160 typedef struct camera_info {
161     /**
162      * The direction that the camera faces to. See system/core/include/system/camera.h
163      * for camera facing definitions.
164      *
165      * Version information (based on camera_module_t.common.module_api_version):
166      *
167      * CAMERA_MODULE_API_VERSION_2_3 or lower:
168      *
169      *   It should be CAMERA_FACING_BACK or CAMERA_FACING_FRONT.
170      *
171      * CAMERA_MODULE_API_VERSION_2_4 or higher:
172      *
173      *   It should be CAMERA_FACING_BACK, CAMERA_FACING_FRONT or
174      *   CAMERA_FACING_EXTERNAL.
175      */
176     int facing;
177 
178     /**
179      * The orientation of the camera image. The value is the angle that the
180      * camera image needs to be rotated clockwise so it shows correctly on the
181      * display in its natural orientation. It should be 0, 90, 180, or 270.
182      *
183      * For example, suppose a device has a naturally tall screen. The
184      * back-facing camera sensor is mounted in landscape. You are looking at the
185      * screen. If the top side of the camera sensor is aligned with the right
186      * edge of the screen in natural orientation, the value should be 90. If the
187      * top side of a front-facing camera sensor is aligned with the right of the
188      * screen, the value should be 270.
189      *
190      * Version information (based on camera_module_t.common.module_api_version):
191      *
192      * CAMERA_MODULE_API_VERSION_2_3 or lower:
193      *
194      *   Valid in all camera_module versions.
195      *
196      * CAMERA_MODULE_API_VERSION_2_4 or higher:
197      *
198      *   Valid if camera facing is CAMERA_FACING_BACK or CAMERA_FACING_FRONT,
199      *   not valid if camera facing is CAMERA_FACING_EXTERNAL.
200      */
201     int orientation;
202 
203     /**
204      * The value of camera_device_t.common.version.
205      *
206      * Version information (based on camera_module_t.common.module_api_version):
207      *
208      *  CAMERA_MODULE_API_VERSION_1_0:
209      *
210      *    Not valid. Can be assumed to be CAMERA_DEVICE_API_VERSION_1_0. Do
211      *    not read this field.
212      *
213      *  CAMERA_MODULE_API_VERSION_2_0 or higher:
214      *
215      *    Always valid
216      *
217      */
218     uint32_t device_version;
219 
220     /**
221      * The camera's fixed characteristics, which include all static camera metadata
222      * specified in system/media/camera/docs/docs.html. This should be a sorted metadata
223      * buffer, and may not be modified or freed by the caller. The pointer should remain
224      * valid for the lifetime of the camera module, and values in it may not
225      * change after it is returned by get_camera_info().
226      *
227      * Version information (based on camera_module_t.common.module_api_version):
228      *
229      *  CAMERA_MODULE_API_VERSION_1_0:
230      *
231      *    Not valid. Extra characteristics are not available. Do not read this
232      *    field.
233      *
234      *  CAMERA_MODULE_API_VERSION_2_0 or higher:
235      *
236      *    Valid if device_version >= CAMERA_DEVICE_API_VERSION_2_0. Do not read
237      *    otherwise.
238      *
239      */
240     const camera_metadata_t *static_camera_characteristics;
241 
242     /**
243      * The total resource "cost" of using this camera, represented as an integer
244      * value in the range [0, 100] where 100 represents total usage of the shared
245      * resource that is the limiting bottleneck of the camera subsystem.  This may
246      * be a very rough estimate, and is used as a hint to the camera service to
247      * determine when to disallow multiple applications from simultaneously
248      * opening different cameras advertised by the camera service.
249      *
250      * The camera service must be able to simultaneously open and use any
251      * combination of camera devices exposed by the HAL where the sum of
252      * the resource costs of these cameras is <= 100.  For determining cost,
253      * each camera device must be assumed to be configured and operating at
254      * the maximally resource-consuming framerate and stream size settings
255      * available in the configuration settings exposed for that device through
256      * the camera metadata.
257      *
258      * The camera service may still attempt to simultaneously open combinations
259      * of camera devices with a total resource cost > 100.  This may succeed or
260      * fail.  If this succeeds, combinations of configurations that are not
261      * supported due to resource constraints from having multiple open devices
262      * should fail during the configure calls.  If the total resource cost is
263      * <= 100, open and configure should never fail for any stream configuration
264      * settings or other device capabilities that would normally succeed for a
265      * device when it is the only open camera device.
266      *
267      * This field will be used to determine whether background applications are
268      * allowed to use this camera device while other applications are using other
269      * camera devices.  Note: multiple applications will never be allowed by the
270      * camera service to simultaneously open the same camera device.
271      *
272      * Example use cases:
273      *
274      * Ex. 1: Camera Device 0 = Back Camera
275      *        Camera Device 1 = Front Camera
276      *   - Using both camera devices causes a large framerate slowdown due to
277      *     limited ISP bandwidth.
278      *
279      *   Configuration:
280      *
281      *   Camera Device 0 - resource_cost = 51
282      *                     conflicting_devices = null
283      *   Camera Device 1 - resource_cost = 51
284      *                     conflicting_devices = null
285      *
286      *   Result:
287      *
288      *   Since the sum of the resource costs is > 100, if a higher-priority
289      *   application has either device open, no lower-priority applications will be
290      *   allowed by the camera service to open either device.  If a lower-priority
291      *   application is using a device that a higher-priority subsequently attempts
292      *   to open, the lower-priority application will be forced to disconnect the
293      *   the device.
294      *
295      *   If the highest-priority application chooses, it may still attempt to open
296      *   both devices (since these devices are not listed as conflicting in the
297      *   conflicting_devices fields), but usage of these devices may fail in the
298      *   open or configure calls.
299      *
300      * Ex. 2: Camera Device 0 = Left Back Camera
301      *        Camera Device 1 = Right Back Camera
302      *        Camera Device 2 = Combined stereo camera using both right and left
303      *                          back camera sensors used by devices 0, and 1
304      *        Camera Device 3 = Front Camera
305      *   - Due to do hardware constraints, up to two cameras may be open at once. The
306      *     combined stereo camera may never be used at the same time as either of the
307      *     two back camera devices (device 0, 1), and typically requires too much
308      *     bandwidth to use at the same time as the front camera (device 3).
309      *
310      *   Configuration:
311      *
312      *   Camera Device 0 - resource_cost = 50
313      *                     conflicting_devices = { 2 }
314      *   Camera Device 1 - resource_cost = 50
315      *                     conflicting_devices = { 2 }
316      *   Camera Device 2 - resource_cost = 100
317      *                     conflicting_devices = { 0, 1 }
318      *   Camera Device 3 - resource_cost = 50
319      *                     conflicting_devices = null
320      *
321      *   Result:
322      *
323      *   Based on the conflicting_devices fields, the camera service guarantees that
324      *   the following sets of open devices will never be allowed: { 1, 2 }, { 0, 2 }.
325      *
326      *   Based on the resource_cost fields, if a high-priority foreground application
327      *   is using camera device 0, a background application would be allowed to open
328      *   camera device 1 or 3 (but would be forced to disconnect it again if the
329      *   foreground application opened another device).
330      *
331      *   The highest priority application may still attempt to simultaneously open
332      *   devices 0, 2, and 3, but the HAL may fail in open or configure calls for
333      *   this combination.
334      *
335      * Ex. 3: Camera Device 0 = Back Camera
336      *        Camera Device 1 = Front Camera
337      *        Camera Device 2 = Low-power Front Camera that uses the same
338      *                          sensor as device 1, but only exposes image stream
339      *                          resolutions that can be used in low-power mode
340      *  - Using both front cameras (device 1, 2) at the same time is impossible due
341      *    a shared physical sensor.  Using the back and "high-power" front camera
342      *    (device 1) may be impossible for some stream configurations due to hardware
343      *    limitations, but the "low-power" front camera option may always be used as
344      *    it has special dedicated hardware.
345      *
346      *   Configuration:
347      *
348      *   Camera Device 0 - resource_cost = 100
349      *                     conflicting_devices = null
350      *   Camera Device 1 - resource_cost = 100
351      *                     conflicting_devices = { 2 }
352      *   Camera Device 2 - resource_cost = 0
353      *                     conflicting_devices = { 1 }
354      *   Result:
355      *
356      *   Based on the conflicting_devices fields, the camera service guarantees that
357      *   the following sets of open devices will never be allowed: { 1, 2 }.
358      *
359      *   Based on the resource_cost fields, only the highest priority application
360      *   may attempt to open both device 0 and 1 at the same time. If a higher-priority
361      *   application is not using device 1 or 2, a low-priority background application
362      *   may open device 2 (but will be forced to disconnect it if a higher-priority
363      *   application subsequently opens device 1 or 2).
364      *
365      * Version information (based on camera_module_t.common.module_api_version):
366      *
367      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
368      *
369      *    Not valid.  Can be assumed to be 100.  Do not read this field.
370      *
371      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
372      *
373      *    Always valid.
374      */
375     int resource_cost;
376 
377     /**
378      * An array of camera device IDs represented as NULL-terminated strings
379      * indicating other devices that cannot be simultaneously opened while this
380      * camera device is in use.
381      *
382      * This field is intended to be used to indicate that this camera device
383      * is a composite of several other camera devices, or otherwise has
384      * hardware dependencies that prohibit simultaneous usage. If there are no
385      * dependencies, a NULL may be returned in this field to indicate this.
386      *
387      * The camera service will never simultaneously open any of the devices
388      * in this list while this camera device is open.
389      *
390      * The strings pointed to in this field will not be cleaned up by the camera
391      * service, and must remain while this device is plugged in.
392      *
393      * Version information (based on camera_module_t.common.module_api_version):
394      *
395      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
396      *
397      *    Not valid.  Can be assumed to be NULL.  Do not read this field.
398      *
399      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
400      *
401      *    Always valid.
402      */
403     char** conflicting_devices;
404 
405     /**
406      * The length of the array given in the conflicting_devices field.
407      *
408      * Version information (based on camera_module_t.common.module_api_version):
409      *
410      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
411      *
412      *    Not valid.  Can be assumed to be 0.  Do not read this field.
413      *
414      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
415      *
416      *    Always valid.
417      */
418     size_t conflicting_devices_length;
419 
420 } camera_info_t;
421 
422 /**
423  * camera_device_status_t:
424  *
425  * The current status of the camera device, as provided by the HAL through the
426  * camera_module_callbacks.camera_device_status_change() call.
427  *
428  * At module load time, the framework will assume all camera devices are in the
429  * CAMERA_DEVICE_STATUS_PRESENT state. The HAL should invoke
430  * camera_module_callbacks::camera_device_status_change to inform the framework
431  * of any initially NOT_PRESENT devices.
432  *
433  * Allowed transitions:
434  *      PRESENT            -> NOT_PRESENT
435  *      NOT_PRESENT        -> ENUMERATING
436  *      NOT_PRESENT        -> PRESENT
437  *      ENUMERATING        -> PRESENT
438  *      ENUMERATING        -> NOT_PRESENT
439  */
440 typedef enum camera_device_status {
441     /**
442      * The camera device is not currently connected, and opening it will return
443      * failure.
444      *
445      * Version information (based on camera_module_t.common.module_api_version):
446      *
447      * CAMERA_MODULE_API_VERSION_2_3 or lower:
448      *
449      *   Calls to get_camera_info must still succeed, and provide the same information
450      *   it would if the camera were connected.
451      *
452      * CAMERA_MODULE_API_VERSION_2_4:
453      *
454      *   The camera device at this status must return -EINVAL for get_camera_info call,
455      *   as the device is not connected.
456      */
457     CAMERA_DEVICE_STATUS_NOT_PRESENT = 0,
458 
459     /**
460      * The camera device is connected, and opening it will succeed.
461      *
462      * CAMERA_MODULE_API_VERSION_2_3 or lower:
463      *
464      *   The information returned by get_camera_info cannot change due to this status
465      *   change. By default, the framework will assume all devices are in this state.
466      *
467      * CAMERA_MODULE_API_VERSION_2_4:
468      *
469      *   The information returned by get_camera_info will become valid after a device's
470      *   status changes to this. By default, the framework will assume all devices are in
471      *   this state.
472      */
473     CAMERA_DEVICE_STATUS_PRESENT = 1,
474 
475     /**
476      * The camera device is connected, but it is undergoing an enumeration and
477      * so opening the device will return -EBUSY.
478      *
479      * CAMERA_MODULE_API_VERSION_2_3 or lower:
480      *
481      *   Calls to get_camera_info must still succeed, as if the camera was in the
482      *   PRESENT status.
483      *
484      * CAMERA_MODULE_API_VERSION_2_4:
485      *
486      *   The camera device at this status must return -EINVAL for get_camera_info for call,
487      *   as the device is not ready.
488      */
489     CAMERA_DEVICE_STATUS_ENUMERATING = 2,
490 
491 } camera_device_status_t;
492 
493 /**
494  * torch_mode_status_t:
495  *
496  * The current status of the torch mode, as provided by the HAL through the
497  * camera_module_callbacks.torch_mode_status_change() call.
498  *
499  * The torch mode status of a camera device is applicable only when the camera
500  * device is present. The framework will not call set_torch_mode() to turn on
501  * torch mode of a camera device if the camera device is not present. At module
502  * load time, the framework will assume torch modes are in the
503  * TORCH_MODE_STATUS_AVAILABLE_OFF state if the camera device is present and
504  * android.flash.info.available is reported as true via get_camera_info() call.
505  *
506  * The behaviors of the camera HAL module that the framework expects in the
507  * following situations when a camera device's status changes:
508  *  1. A previously-disconnected camera device becomes connected.
509  *      After camera_module_callbacks::camera_device_status_change() is invoked
510  *      to inform the framework that the camera device is present, the framework
511  *      will assume the camera device's torch mode is in
512  *      TORCH_MODE_STATUS_AVAILABLE_OFF state. The camera HAL module does not need
513  *      to invoke camera_module_callbacks::torch_mode_status_change() unless the
514  *      flash unit is unavailable to use by set_torch_mode().
515  *
516  *  2. A previously-connected camera becomes disconnected.
517  *      After camera_module_callbacks::camera_device_status_change() is invoked
518  *      to inform the framework that the camera device is not present, the
519  *      framework will not call set_torch_mode() for the disconnected camera
520  *      device until its flash unit becomes available again. The camera HAL
521  *      module does not need to invoke
522  *      camera_module_callbacks::torch_mode_status_change() separately to inform
523  *      that the flash unit has become unavailable.
524  *
525  *  3. open() is called to open a camera device.
526  *      The camera HAL module must invoke
527  *      camera_module_callbacks::torch_mode_status_change() for all flash units
528  *      that have entered TORCH_MODE_STATUS_NOT_AVAILABLE state and can not be
529  *      turned on by calling set_torch_mode() anymore due to this open() call.
530  *      open() must not trigger TORCH_MODE_STATUS_AVAILABLE_OFF before
531  *      TORCH_MODE_STATUS_NOT_AVAILABLE for all flash units that have become
532  *      unavailable.
533  *
534  *  4. close() is called to close a camera device.
535  *      The camera HAL module must invoke
536  *      camera_module_callbacks::torch_mode_status_change() for all flash units
537  *      that have entered TORCH_MODE_STATUS_AVAILABLE_OFF state and can be turned
538  *      on by calling set_torch_mode() again because of enough resources freed
539  *      up by this close() call.
540  *
541  *  Note that the framework calling set_torch_mode() successfully must trigger
542  *  TORCH_MODE_STATUS_AVAILABLE_OFF or TORCH_MODE_STATUS_AVAILABLE_ON callback
543  *  for the given camera device. Additionally it must trigger
544  *  TORCH_MODE_STATUS_AVAILABLE_OFF callbacks for other previously-on torch
545  *  modes if HAL cannot keep multiple torch modes on simultaneously.
546  */
547 typedef enum torch_mode_status {
548 
549     /**
550      * The flash unit is no longer available and the torch mode can not be
551      * turned on by calling set_torch_mode(). If the torch mode is on, it
552      * will be turned off by HAL before HAL calls torch_mode_status_change().
553      */
554     TORCH_MODE_STATUS_NOT_AVAILABLE = 0,
555 
556     /**
557      * A torch mode has become off and available to be turned on via
558      * set_torch_mode(). This may happen in the following
559      * cases:
560      *   1. After the resources to turn on the torch mode have become available.
561      *   2. After set_torch_mode() is called to turn off the torch mode.
562      *   3. After the framework turned on the torch mode of some other camera
563      *      device and HAL had to turn off the torch modes of any camera devices
564      *      that were previously on.
565      */
566     TORCH_MODE_STATUS_AVAILABLE_OFF = 1,
567 
568     /**
569      * A torch mode has become on and available to be turned off via
570      * set_torch_mode(). This can happen only after set_torch_mode() is called
571      * to turn on the torch mode.
572      */
573     TORCH_MODE_STATUS_AVAILABLE_ON = 2,
574 
575 } torch_mode_status_t;
576 
577 /**
578  * Callback functions for the camera HAL module to use to inform the framework
579  * of changes to the camera subsystem.
580  *
581  * Version information (based on camera_module_t.common.module_api_version):
582  *
583  * Each callback is called only by HAL modules implementing the indicated
584  * version or higher of the HAL module API interface.
585  *
586  *  CAMERA_MODULE_API_VERSION_2_1:
587  *    camera_device_status_change()
588  *
589  *  CAMERA_MODULE_API_VERSION_2_4:
590  *    torch_mode_status_change()
591 
592  */
593 typedef struct camera_module_callbacks {
594 
595     /**
596      * camera_device_status_change:
597      *
598      * Callback to the framework to indicate that the state of a specific camera
599      * device has changed. At module load time, the framework will assume all
600      * camera devices are in the CAMERA_DEVICE_STATUS_PRESENT state. The HAL
601      * must call this method to inform the framework of any initially
602      * NOT_PRESENT devices.
603      *
604      * This callback is added for CAMERA_MODULE_API_VERSION_2_1.
605      *
606      * camera_module_callbacks: The instance of camera_module_callbacks_t passed
607      *   to the module with set_callbacks.
608      *
609      * camera_id: The ID of the camera device that has a new status.
610      *
611      * new_status: The new status code, one of the camera_device_status_t enums,
612      *   or a platform-specific status.
613      *
614      */
615     void (*camera_device_status_change)(const struct camera_module_callbacks*,
616             int camera_id,
617             int new_status);
618 
619     /**
620      * torch_mode_status_change:
621      *
622      * Callback to the framework to indicate that the state of the torch mode
623      * of the flash unit associated with a specific camera device has changed.
624      * At module load time, the framework will assume the torch modes are in
625      * the TORCH_MODE_STATUS_AVAILABLE_OFF state if android.flash.info.available
626      * is reported as true via get_camera_info() call.
627      *
628      * This callback is added for CAMERA_MODULE_API_VERSION_2_4.
629      *
630      * camera_module_callbacks: The instance of camera_module_callbacks_t
631      *   passed to the module with set_callbacks.
632      *
633      * camera_id: The ID of camera device whose flash unit has a new torch mode
634      *   status.
635      *
636      * new_status: The new status code, one of the torch_mode_status_t enums.
637      */
638     void (*torch_mode_status_change)(const struct camera_module_callbacks*,
639             const char* camera_id,
640             int new_status);
641 
642 
643 } camera_module_callbacks_t;
644 
645 typedef struct camera_module {
646     /**
647      * Common methods of the camera module.  This *must* be the first member of
648      * camera_module as users of this structure will cast a hw_module_t to
649      * camera_module pointer in contexts where it's known the hw_module_t
650      * references a camera_module.
651      *
652      * The return values for common.methods->open for camera_module are:
653      *
654      * 0:           On a successful open of the camera device.
655      *
656      * -ENODEV:     The camera device cannot be opened due to an internal
657      *              error.
658      *
659      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
660      *              and/or the module is invalid.
661      *
662      * -EBUSY:      The camera device was already opened for this camera id
663      *              (by using this method or open_legacy),
664      *              regardless of the device HAL version it was opened as.
665      *
666      * -EUSERS:     The maximal number of camera devices that can be
667      *              opened concurrently were opened already, either by
668      *              this method or the open_legacy method.
669      *
670      * All other return values from common.methods->open will be treated as
671      * -ENODEV.
672      */
673     hw_module_t common;
674 
675     /**
676      * get_number_of_cameras:
677      *
678      * Returns the number of camera devices accessible through the camera
679      * module.  The camera devices are numbered 0 through N-1, where N is the
680      * value returned by this call. The name of the camera device for open() is
681      * simply the number converted to a string. That is, "0" for camera ID 0,
682      * "1" for camera ID 1.
683      *
684      * Version information (based on camera_module_t.common.module_api_version):
685      *
686      * CAMERA_MODULE_API_VERSION_2_3 or lower:
687      *
688      *   The value here must be static, and cannot change after the first call
689      *   to this method.
690      *
691      * CAMERA_MODULE_API_VERSION_2_4 or higher:
692      *
693      *   The value here must be static, and must count only built-in cameras,
694      *   which have CAMERA_FACING_BACK or CAMERA_FACING_FRONT camera facing values
695      *   (camera_info.facing). The HAL must not include the external cameras
696      *   (camera_info.facing == CAMERA_FACING_EXTERNAL) into the return value
697      *   of this call. Frameworks will use camera_device_status_change callback
698      *   to manage number of external cameras.
699      */
700     int (*get_number_of_cameras)(void);
701 
702     /**
703      * get_camera_info:
704      *
705      * Return the static camera information for a given camera device. This
706      * information may not change for a camera device.
707      *
708      * Return values:
709      *
710      * 0:           On a successful operation
711      *
712      * -ENODEV:     The information cannot be provided due to an internal
713      *              error.
714      *
715      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
716      *              and/or the module is invalid.
717      *
718      * Version information (based on camera_module_t.common.module_api_version):
719      *
720      * CAMERA_MODULE_API_VERSION_2_4 or higher:
721      *
722      *   When a camera is disconnected, its camera id becomes invalid. Calling this
723      *   this method with this invalid camera id will get -EINVAL and NULL camera
724      *   static metadata (camera_info.static_camera_characteristics).
725      */
726     int (*get_camera_info)(int camera_id, struct camera_info *info);
727 
728     /**
729      * set_callbacks:
730      *
731      * Provide callback function pointers to the HAL module to inform framework
732      * of asynchronous camera module events. The framework will call this
733      * function once after initial camera HAL module load, after the
734      * get_number_of_cameras() method is called for the first time, and before
735      * any other calls to the module.
736      *
737      * Version information (based on camera_module_t.common.module_api_version):
738      *
739      *  CAMERA_MODULE_API_VERSION_1_0, CAMERA_MODULE_API_VERSION_2_0:
740      *
741      *    Not provided by HAL module. Framework may not call this function.
742      *
743      *  CAMERA_MODULE_API_VERSION_2_1:
744      *
745      *    Valid to be called by the framework.
746      *
747      * Return values:
748      *
749      * 0:           On a successful operation
750      *
751      * -ENODEV:     The operation cannot be completed due to an internal
752      *              error.
753      *
754      * -EINVAL:     The input arguments are invalid, i.e. the callbacks are
755      *              null
756      */
757     int (*set_callbacks)(const camera_module_callbacks_t *callbacks);
758 
759     /**
760      * get_vendor_tag_ops:
761      *
762      * Get methods to query for vendor extension metadata tag information. The
763      * HAL should fill in all the vendor tag operation methods, or leave ops
764      * unchanged if no vendor tags are defined.
765      *
766      * The vendor_tag_ops structure used here is defined in:
767      * system/media/camera/include/system/vendor_tags.h
768      *
769      * Version information (based on camera_module_t.common.module_api_version):
770      *
771      *  CAMERA_MODULE_API_VERSION_1_x/2_0/2_1:
772      *    Not provided by HAL module. Framework may not call this function.
773      *
774      *  CAMERA_MODULE_API_VERSION_2_2:
775      *    Valid to be called by the framework.
776      */
777     void (*get_vendor_tag_ops)(vendor_tag_ops_t* ops);
778 
779     /**
780      * open_legacy:
781      *
782      * Open a specific legacy camera HAL device if multiple device HAL API
783      * versions are supported by this camera HAL module. For example, if the
784      * camera module supports both CAMERA_DEVICE_API_VERSION_1_0 and
785      * CAMERA_DEVICE_API_VERSION_3_2 device API for the same camera id,
786      * framework can call this function to open the camera device as
787      * CAMERA_DEVICE_API_VERSION_1_0 device.
788      *
789      * This is an optional method. A Camera HAL module does not need to support
790      * more than one device HAL version per device, and such modules may return
791      * -ENOSYS for all calls to this method. For all older HAL device API
792      * versions that are not supported, it may return -EOPNOTSUPP. When above
793      * cases occur, The normal open() method (common.methods->open) will be
794      * used by the framework instead.
795      *
796      * Version information (based on camera_module_t.common.module_api_version):
797      *
798      *  CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2:
799      *    Not provided by HAL module. Framework will not call this function.
800      *
801      *  CAMERA_MODULE_API_VERSION_2_3:
802      *    Valid to be called by the framework.
803      *
804      * Return values:
805      *
806      * 0:           On a successful open of the camera device.
807      *
808      * -ENOSYS      This method is not supported.
809      *
810      * -EOPNOTSUPP: The requested HAL version is not supported by this method.
811      *
812      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
813      *              and/or the module is invalid.
814      *
815      * -EBUSY:      The camera device was already opened for this camera id
816      *              (by using this method or common.methods->open method),
817      *              regardless of the device HAL version it was opened as.
818      *
819      * -EUSERS:     The maximal number of camera devices that can be
820      *              opened concurrently were opened already, either by
821      *              this method or common.methods->open method.
822      */
823     int (*open_legacy)(const struct hw_module_t* module, const char* id,
824             uint32_t halVersion, struct hw_device_t** device);
825 
826     /**
827      * set_torch_mode:
828      *
829      * Turn on or off the torch mode of the flash unit associated with a given
830      * camera ID. If the operation is successful, HAL must notify the framework
831      * torch state by invoking
832      * camera_module_callbacks.torch_mode_status_change() with the new state.
833      *
834      * The camera device has a higher priority accessing the flash unit. When
835      * there are any resource conflicts, such as open() is called to open a
836      * camera device, HAL module must notify the framework through
837      * camera_module_callbacks.torch_mode_status_change() that the
838      * torch mode has been turned off and the torch mode state has become
839      * TORCH_MODE_STATUS_NOT_AVAILABLE. When resources to turn on torch mode
840      * become available again, HAL module must notify the framework through
841      * camera_module_callbacks.torch_mode_status_change() that the torch mode
842      * state has become TORCH_MODE_STATUS_AVAILABLE_OFF for set_torch_mode() to
843      * be called.
844      *
845      * When the framework calls set_torch_mode() to turn on the torch mode of a
846      * flash unit, if HAL cannot keep multiple torch modes on simultaneously,
847      * HAL should turn off the torch mode that was turned on by
848      * a previous set_torch_mode() call and notify the framework that the torch
849      * mode state of that flash unit has become TORCH_MODE_STATUS_AVAILABLE_OFF.
850      *
851      * Version information (based on camera_module_t.common.module_api_version):
852      *
853      * CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2/2_3:
854      *   Not provided by HAL module. Framework will not call this function.
855      *
856      * CAMERA_MODULE_API_VERSION_2_4:
857      *   Valid to be called by the framework.
858      *
859      * Return values:
860      *
861      * 0:           On a successful operation.
862      *
863      * -ENOSYS:     The camera device does not support this operation. It is
864      *              returned if and only if android.flash.info.available is
865      *              false.
866      *
867      * -EBUSY:      The camera device is already in use.
868      *
869      * -EUSERS:     The resources needed to turn on the torch mode are not
870      *              available, typically because other camera devices are
871      *              holding the resources to make using the flash unit not
872      *              possible.
873      *
874      * -EINVAL:     camera_id is invalid.
875      *
876      */
877     int (*set_torch_mode)(const char* camera_id, bool enabled);
878 
879     /**
880      * init:
881      *
882      * This method is called by the camera service before any other methods
883      * are invoked, right after the camera HAL library has been successfully
884      * loaded. It may be left as NULL by the HAL module, if no initialization
885      * in needed.
886      *
887      * It can be used by HAL implementations to perform initialization and
888      * other one-time operations.
889      *
890      * Version information (based on camera_module_t.common.module_api_version):
891      *
892      * CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2/2_3:
893      *   Not provided by HAL module. Framework will not call this function.
894      *
895      * CAMERA_MODULE_API_VERSION_2_4:
896      *   If not NULL, will always be called by the framework once after the HAL
897      *   module is loaded, before any other HAL module method is called.
898      *
899      * Return values:
900      *
901      * 0:           On a successful operation.
902      *
903      * -ENODEV:     Initialization cannot be completed due to an internal
904      *              error. The HAL must be assumed to be in a nonfunctional
905      *              state.
906      *
907      */
908     int (*init)();
909 
910     /* reserved for future use */
911     void* reserved[5];
912 } camera_module_t;
913 
914 __END_DECLS
915 
916 #endif /* ANDROID_INCLUDE_CAMERA_COMMON_H */
917