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) // DEPRECATED
144 #define CAMERA_DEVICE_API_VERSION_2_0 HARDWARE_DEVICE_API_VERSION(2, 0) // NO LONGER SUPPORTED
145 #define CAMERA_DEVICE_API_VERSION_2_1 HARDWARE_DEVICE_API_VERSION(2, 1) // NO LONGER SUPPORTED
146 #define CAMERA_DEVICE_API_VERSION_3_0 HARDWARE_DEVICE_API_VERSION(3, 0) // NO LONGER SUPPORTED
147 #define CAMERA_DEVICE_API_VERSION_3_1 HARDWARE_DEVICE_API_VERSION(3, 1) // NO LONGER SUPPORTED
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 #define CAMERA_DEVICE_API_VERSION_3_4 HARDWARE_DEVICE_API_VERSION(3, 4)
151 #define CAMERA_DEVICE_API_VERSION_3_5 HARDWARE_DEVICE_API_VERSION(3, 5)
152 
153 // Device version 3.5 is current, older HAL camera device versions are not
154 // recommended for new devices.
155 #define CAMERA_DEVICE_API_VERSION_CURRENT CAMERA_DEVICE_API_VERSION_3_5
156 
157 /**
158  * Defined in /system/media/camera/include/system/camera_metadata.h
159  */
160 typedef struct camera_metadata camera_metadata_t;
161 
162 typedef struct camera_info {
163     /**
164      * The direction that the camera faces to. See system/core/include/system/camera.h
165      * for camera facing definitions.
166      *
167      * Version information (based on camera_module_t.common.module_api_version):
168      *
169      * CAMERA_MODULE_API_VERSION_2_3 or lower:
170      *
171      *   It should be CAMERA_FACING_BACK or CAMERA_FACING_FRONT.
172      *
173      * CAMERA_MODULE_API_VERSION_2_4 or higher:
174      *
175      *   It should be CAMERA_FACING_BACK, CAMERA_FACING_FRONT or
176      *   CAMERA_FACING_EXTERNAL.
177      */
178     int facing;
179 
180     /**
181      * The orientation of the camera image. The value is the angle that the
182      * camera image needs to be rotated clockwise so it shows correctly on the
183      * display in its natural orientation. It should be 0, 90, 180, or 270.
184      *
185      * For example, suppose a device has a naturally tall screen. The
186      * back-facing camera sensor is mounted in landscape. You are looking at the
187      * screen. If the top side of the camera sensor is aligned with the right
188      * edge of the screen in natural orientation, the value should be 90. If the
189      * top side of a front-facing camera sensor is aligned with the right of the
190      * screen, the value should be 270.
191      *
192      * Version information (based on camera_module_t.common.module_api_version):
193      *
194      * CAMERA_MODULE_API_VERSION_2_3 or lower:
195      *
196      *   Valid in all camera_module versions.
197      *
198      * CAMERA_MODULE_API_VERSION_2_4 or higher:
199      *
200      *   Valid if camera facing is CAMERA_FACING_BACK or CAMERA_FACING_FRONT,
201      *   not valid if camera facing is CAMERA_FACING_EXTERNAL.
202      */
203     int orientation;
204 
205     /**
206      * The value of camera_device_t.common.version.
207      *
208      * Version information (based on camera_module_t.common.module_api_version):
209      *
210      *  CAMERA_MODULE_API_VERSION_1_0:
211      *
212      *    Not valid. Can be assumed to be CAMERA_DEVICE_API_VERSION_1_0. Do
213      *    not read this field.
214      *
215      *  CAMERA_MODULE_API_VERSION_2_0 or higher:
216      *
217      *    Always valid
218      *
219      */
220     uint32_t device_version;
221 
222     /**
223      * The camera's fixed characteristics, which include all static camera metadata
224      * specified in system/media/camera/docs/docs.html. This should be a sorted metadata
225      * buffer, and may not be modified or freed by the caller. The pointer should remain
226      * valid for the lifetime of the camera module, and values in it may not
227      * change after it is returned by get_camera_info().
228      *
229      * Version information (based on camera_module_t.common.module_api_version):
230      *
231      *  CAMERA_MODULE_API_VERSION_1_0:
232      *
233      *    Not valid. Extra characteristics are not available. Do not read this
234      *    field.
235      *
236      *  CAMERA_MODULE_API_VERSION_2_0 or higher:
237      *
238      *    Valid if device_version >= CAMERA_DEVICE_API_VERSION_2_0. Do not read
239      *    otherwise.
240      *
241      */
242     const camera_metadata_t *static_camera_characteristics;
243 
244     /**
245      * The total resource "cost" of using this camera, represented as an integer
246      * value in the range [0, 100] where 100 represents total usage of the shared
247      * resource that is the limiting bottleneck of the camera subsystem.  This may
248      * be a very rough estimate, and is used as a hint to the camera service to
249      * determine when to disallow multiple applications from simultaneously
250      * opening different cameras advertised by the camera service.
251      *
252      * The camera service must be able to simultaneously open and use any
253      * combination of camera devices exposed by the HAL where the sum of
254      * the resource costs of these cameras is <= 100.  For determining cost,
255      * each camera device must be assumed to be configured and operating at
256      * the maximally resource-consuming framerate and stream size settings
257      * available in the configuration settings exposed for that device through
258      * the camera metadata.
259      *
260      * The camera service may still attempt to simultaneously open combinations
261      * of camera devices with a total resource cost > 100.  This may succeed or
262      * fail.  If this succeeds, combinations of configurations that are not
263      * supported due to resource constraints from having multiple open devices
264      * should fail during the configure calls.  If the total resource cost is
265      * <= 100, open and configure should never fail for any stream configuration
266      * settings or other device capabilities that would normally succeed for a
267      * device when it is the only open camera device.
268      *
269      * This field will be used to determine whether background applications are
270      * allowed to use this camera device while other applications are using other
271      * camera devices.  Note: multiple applications will never be allowed by the
272      * camera service to simultaneously open the same camera device.
273      *
274      * Example use cases:
275      *
276      * Ex. 1: Camera Device 0 = Back Camera
277      *        Camera Device 1 = Front Camera
278      *   - Using both camera devices causes a large framerate slowdown due to
279      *     limited ISP bandwidth.
280      *
281      *   Configuration:
282      *
283      *   Camera Device 0 - resource_cost = 51
284      *                     conflicting_devices = null
285      *   Camera Device 1 - resource_cost = 51
286      *                     conflicting_devices = null
287      *
288      *   Result:
289      *
290      *   Since the sum of the resource costs is > 100, if a higher-priority
291      *   application has either device open, no lower-priority applications will be
292      *   allowed by the camera service to open either device.  If a lower-priority
293      *   application is using a device that a higher-priority subsequently attempts
294      *   to open, the lower-priority application will be forced to disconnect the
295      *   the device.
296      *
297      *   If the highest-priority application chooses, it may still attempt to open
298      *   both devices (since these devices are not listed as conflicting in the
299      *   conflicting_devices fields), but usage of these devices may fail in the
300      *   open or configure calls.
301      *
302      * Ex. 2: Camera Device 0 = Left Back Camera
303      *        Camera Device 1 = Right Back Camera
304      *        Camera Device 2 = Combined stereo camera using both right and left
305      *                          back camera sensors used by devices 0, and 1
306      *        Camera Device 3 = Front Camera
307      *   - Due to do hardware constraints, up to two cameras may be open at once. The
308      *     combined stereo camera may never be used at the same time as either of the
309      *     two back camera devices (device 0, 1), and typically requires too much
310      *     bandwidth to use at the same time as the front camera (device 3).
311      *
312      *   Configuration:
313      *
314      *   Camera Device 0 - resource_cost = 50
315      *                     conflicting_devices = { 2 }
316      *   Camera Device 1 - resource_cost = 50
317      *                     conflicting_devices = { 2 }
318      *   Camera Device 2 - resource_cost = 100
319      *                     conflicting_devices = { 0, 1 }
320      *   Camera Device 3 - resource_cost = 50
321      *                     conflicting_devices = null
322      *
323      *   Result:
324      *
325      *   Based on the conflicting_devices fields, the camera service guarantees that
326      *   the following sets of open devices will never be allowed: { 1, 2 }, { 0, 2 }.
327      *
328      *   Based on the resource_cost fields, if a high-priority foreground application
329      *   is using camera device 0, a background application would be allowed to open
330      *   camera device 1 or 3 (but would be forced to disconnect it again if the
331      *   foreground application opened another device).
332      *
333      *   The highest priority application may still attempt to simultaneously open
334      *   devices 0, 2, and 3, but the HAL may fail in open or configure calls for
335      *   this combination.
336      *
337      * Ex. 3: Camera Device 0 = Back Camera
338      *        Camera Device 1 = Front Camera
339      *        Camera Device 2 = Low-power Front Camera that uses the same
340      *                          sensor as device 1, but only exposes image stream
341      *                          resolutions that can be used in low-power mode
342      *  - Using both front cameras (device 1, 2) at the same time is impossible due
343      *    a shared physical sensor.  Using the back and "high-power" front camera
344      *    (device 1) may be impossible for some stream configurations due to hardware
345      *    limitations, but the "low-power" front camera option may always be used as
346      *    it has special dedicated hardware.
347      *
348      *   Configuration:
349      *
350      *   Camera Device 0 - resource_cost = 100
351      *                     conflicting_devices = null
352      *   Camera Device 1 - resource_cost = 100
353      *                     conflicting_devices = { 2 }
354      *   Camera Device 2 - resource_cost = 0
355      *                     conflicting_devices = { 1 }
356      *   Result:
357      *
358      *   Based on the conflicting_devices fields, the camera service guarantees that
359      *   the following sets of open devices will never be allowed: { 1, 2 }.
360      *
361      *   Based on the resource_cost fields, only the highest priority application
362      *   may attempt to open both device 0 and 1 at the same time. If a higher-priority
363      *   application is not using device 1 or 2, a low-priority background application
364      *   may open device 2 (but will be forced to disconnect it if a higher-priority
365      *   application subsequently opens device 1 or 2).
366      *
367      * Version information (based on camera_module_t.common.module_api_version):
368      *
369      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
370      *
371      *    Not valid.  Can be assumed to be 100.  Do not read this field.
372      *
373      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
374      *
375      *    Always valid.
376      */
377     int resource_cost;
378 
379     /**
380      * An array of camera device IDs represented as NULL-terminated strings
381      * indicating other devices that cannot be simultaneously opened while this
382      * camera device is in use.
383      *
384      * This field is intended to be used to indicate that this camera device
385      * is a composite of several other camera devices, or otherwise has
386      * hardware dependencies that prohibit simultaneous usage. If there are no
387      * dependencies, a NULL may be returned in this field to indicate this.
388      *
389      * The camera service will never simultaneously open any of the devices
390      * in this list while this camera device is open.
391      *
392      * The strings pointed to in this field will not be cleaned up by the camera
393      * service, and must remain while this device is plugged in.
394      *
395      * Version information (based on camera_module_t.common.module_api_version):
396      *
397      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
398      *
399      *    Not valid.  Can be assumed to be NULL.  Do not read this field.
400      *
401      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
402      *
403      *    Always valid.
404      */
405     char** conflicting_devices;
406 
407     /**
408      * The length of the array given in the conflicting_devices field.
409      *
410      * Version information (based on camera_module_t.common.module_api_version):
411      *
412      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
413      *
414      *    Not valid.  Can be assumed to be 0.  Do not read this field.
415      *
416      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
417      *
418      *    Always valid.
419      */
420     size_t conflicting_devices_length;
421 
422 } camera_info_t;
423 
424 /**
425  * camera_device_status_t:
426  *
427  * The current status of the camera device, as provided by the HAL through the
428  * camera_module_callbacks.camera_device_status_change() call.
429  *
430  * At module load time, the framework will assume all camera devices are in the
431  * CAMERA_DEVICE_STATUS_PRESENT state. The HAL should invoke
432  * camera_module_callbacks::camera_device_status_change to inform the framework
433  * of any initially NOT_PRESENT devices.
434  *
435  * Allowed transitions:
436  *      PRESENT            -> NOT_PRESENT
437  *      NOT_PRESENT        -> ENUMERATING
438  *      NOT_PRESENT        -> PRESENT
439  *      ENUMERATING        -> PRESENT
440  *      ENUMERATING        -> NOT_PRESENT
441  */
442 typedef enum camera_device_status {
443     /**
444      * The camera device is not currently connected, and opening it will return
445      * failure.
446      *
447      * Version information (based on camera_module_t.common.module_api_version):
448      *
449      * CAMERA_MODULE_API_VERSION_2_3 or lower:
450      *
451      *   Calls to get_camera_info must still succeed, and provide the same information
452      *   it would if the camera were connected.
453      *
454      * CAMERA_MODULE_API_VERSION_2_4:
455      *
456      *   The camera device at this status must return -EINVAL for get_camera_info call,
457      *   as the device is not connected.
458      */
459     CAMERA_DEVICE_STATUS_NOT_PRESENT = 0,
460 
461     /**
462      * The camera device is connected, and opening it will succeed.
463      *
464      * CAMERA_MODULE_API_VERSION_2_3 or lower:
465      *
466      *   The information returned by get_camera_info cannot change due to this status
467      *   change. By default, the framework will assume all devices are in this state.
468      *
469      * CAMERA_MODULE_API_VERSION_2_4:
470      *
471      *   The information returned by get_camera_info will become valid after a device's
472      *   status changes to this. By default, the framework will assume all devices are in
473      *   this state.
474      */
475     CAMERA_DEVICE_STATUS_PRESENT = 1,
476 
477     /**
478      * The camera device is connected, but it is undergoing an enumeration and
479      * so opening the device will return -EBUSY.
480      *
481      * CAMERA_MODULE_API_VERSION_2_3 or lower:
482      *
483      *   Calls to get_camera_info must still succeed, as if the camera was in the
484      *   PRESENT status.
485      *
486      * CAMERA_MODULE_API_VERSION_2_4:
487      *
488      *   The camera device at this status must return -EINVAL for get_camera_info for call,
489      *   as the device is not ready.
490      */
491     CAMERA_DEVICE_STATUS_ENUMERATING = 2,
492 
493 } camera_device_status_t;
494 
495 /**
496  * torch_mode_status_t:
497  *
498  * The current status of the torch mode, as provided by the HAL through the
499  * camera_module_callbacks.torch_mode_status_change() call.
500  *
501  * The torch mode status of a camera device is applicable only when the camera
502  * device is present. The framework will not call set_torch_mode() to turn on
503  * torch mode of a camera device if the camera device is not present. At module
504  * load time, the framework will assume torch modes are in the
505  * TORCH_MODE_STATUS_AVAILABLE_OFF state if the camera device is present and
506  * android.flash.info.available is reported as true via get_camera_info() call.
507  *
508  * The behaviors of the camera HAL module that the framework expects in the
509  * following situations when a camera device's status changes:
510  *  1. A previously-disconnected camera device becomes connected.
511  *      After camera_module_callbacks::camera_device_status_change() is invoked
512  *      to inform the framework that the camera device is present, the framework
513  *      will assume the camera device's torch mode is in
514  *      TORCH_MODE_STATUS_AVAILABLE_OFF state. The camera HAL module does not need
515  *      to invoke camera_module_callbacks::torch_mode_status_change() unless the
516  *      flash unit is unavailable to use by set_torch_mode().
517  *
518  *  2. A previously-connected camera becomes disconnected.
519  *      After camera_module_callbacks::camera_device_status_change() is invoked
520  *      to inform the framework that the camera device is not present, the
521  *      framework will not call set_torch_mode() for the disconnected camera
522  *      device until its flash unit becomes available again. The camera HAL
523  *      module does not need to invoke
524  *      camera_module_callbacks::torch_mode_status_change() separately to inform
525  *      that the flash unit has become unavailable.
526  *
527  *  3. open() is called to open a camera device.
528  *      The camera HAL module must invoke
529  *      camera_module_callbacks::torch_mode_status_change() for all flash units
530  *      that have entered TORCH_MODE_STATUS_NOT_AVAILABLE state and can not be
531  *      turned on by calling set_torch_mode() anymore due to this open() call.
532  *      open() must not trigger TORCH_MODE_STATUS_AVAILABLE_OFF before
533  *      TORCH_MODE_STATUS_NOT_AVAILABLE for all flash units that have become
534  *      unavailable.
535  *
536  *  4. close() is called to close a camera device.
537  *      The camera HAL module must invoke
538  *      camera_module_callbacks::torch_mode_status_change() for all flash units
539  *      that have entered TORCH_MODE_STATUS_AVAILABLE_OFF state and can be turned
540  *      on by calling set_torch_mode() again because of enough resources freed
541  *      up by this close() call.
542  *
543  *  Note that the framework calling set_torch_mode() successfully must trigger
544  *  TORCH_MODE_STATUS_AVAILABLE_OFF or TORCH_MODE_STATUS_AVAILABLE_ON callback
545  *  for the given camera device. Additionally it must trigger
546  *  TORCH_MODE_STATUS_AVAILABLE_OFF callbacks for other previously-on torch
547  *  modes if HAL cannot keep multiple torch modes on simultaneously.
548  */
549 typedef enum torch_mode_status {
550 
551     /**
552      * The flash unit is no longer available and the torch mode can not be
553      * turned on by calling set_torch_mode(). If the torch mode is on, it
554      * will be turned off by HAL before HAL calls torch_mode_status_change().
555      */
556     TORCH_MODE_STATUS_NOT_AVAILABLE = 0,
557 
558     /**
559      * A torch mode has become off and available to be turned on via
560      * set_torch_mode(). This may happen in the following
561      * cases:
562      *   1. After the resources to turn on the torch mode have become available.
563      *   2. After set_torch_mode() is called to turn off the torch mode.
564      *   3. After the framework turned on the torch mode of some other camera
565      *      device and HAL had to turn off the torch modes of any camera devices
566      *      that were previously on.
567      */
568     TORCH_MODE_STATUS_AVAILABLE_OFF = 1,
569 
570     /**
571      * A torch mode has become on and available to be turned off via
572      * set_torch_mode(). This can happen only after set_torch_mode() is called
573      * to turn on the torch mode.
574      */
575     TORCH_MODE_STATUS_AVAILABLE_ON = 2,
576 
577 } torch_mode_status_t;
578 
579 /**
580  * Callback functions for the camera HAL module to use to inform the framework
581  * of changes to the camera subsystem.
582  *
583  * Version information (based on camera_module_t.common.module_api_version):
584  *
585  * Each callback is called only by HAL modules implementing the indicated
586  * version or higher of the HAL module API interface.
587  *
588  *  CAMERA_MODULE_API_VERSION_2_1:
589  *    camera_device_status_change()
590  *
591  *  CAMERA_MODULE_API_VERSION_2_4:
592  *    torch_mode_status_change()
593 
594  */
595 typedef struct camera_module_callbacks {
596 
597     /**
598      * camera_device_status_change:
599      *
600      * Callback to the framework to indicate that the state of a specific camera
601      * device has changed. At module load time, the framework will assume all
602      * camera devices are in the CAMERA_DEVICE_STATUS_PRESENT state. The HAL
603      * must call this method to inform the framework of any initially
604      * NOT_PRESENT devices.
605      *
606      * This callback is added for CAMERA_MODULE_API_VERSION_2_1.
607      *
608      * camera_module_callbacks: The instance of camera_module_callbacks_t passed
609      *   to the module with set_callbacks.
610      *
611      * camera_id: The ID of the camera device that has a new status.
612      *
613      * new_status: The new status code, one of the camera_device_status_t enums,
614      *   or a platform-specific status.
615      *
616      */
617     void (*camera_device_status_change)(const struct camera_module_callbacks*,
618             int camera_id,
619             int new_status);
620 
621     /**
622      * torch_mode_status_change:
623      *
624      * Callback to the framework to indicate that the state of the torch mode
625      * of the flash unit associated with a specific camera device has changed.
626      * At module load time, the framework will assume the torch modes are in
627      * the TORCH_MODE_STATUS_AVAILABLE_OFF state if android.flash.info.available
628      * is reported as true via get_camera_info() call.
629      *
630      * This callback is added for CAMERA_MODULE_API_VERSION_2_4.
631      *
632      * camera_module_callbacks: The instance of camera_module_callbacks_t
633      *   passed to the module with set_callbacks.
634      *
635      * camera_id: The ID of camera device whose flash unit has a new torch mode
636      *   status.
637      *
638      * new_status: The new status code, one of the torch_mode_status_t enums.
639      */
640     void (*torch_mode_status_change)(const struct camera_module_callbacks*,
641             const char* camera_id,
642             int new_status);
643 
644 
645 } camera_module_callbacks_t;
646 
647 typedef struct camera_module {
648     /**
649      * Common methods of the camera module.  This *must* be the first member of
650      * camera_module as users of this structure will cast a hw_module_t to
651      * camera_module pointer in contexts where it's known the hw_module_t
652      * references a camera_module.
653      *
654      * The return values for common.methods->open for camera_module are:
655      *
656      * 0:           On a successful open of the camera device.
657      *
658      * -ENODEV:     The camera device cannot be opened due to an internal
659      *              error.
660      *
661      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
662      *              and/or the module is invalid.
663      *
664      * -EBUSY:      The camera device was already opened for this camera id
665      *              (by using this method or open_legacy),
666      *              regardless of the device HAL version it was opened as.
667      *
668      * -EUSERS:     The maximal number of camera devices that can be
669      *              opened concurrently were opened already, either by
670      *              this method or the open_legacy method.
671      *
672      * All other return values from common.methods->open will be treated as
673      * -ENODEV.
674      */
675     hw_module_t common;
676 
677     /**
678      * get_number_of_cameras:
679      *
680      * Returns the number of camera devices accessible through the camera
681      * module.  The camera devices are numbered 0 through N-1, where N is the
682      * value returned by this call. The name of the camera device for open() is
683      * simply the number converted to a string. That is, "0" for camera ID 0,
684      * "1" for camera ID 1.
685      *
686      * Version information (based on camera_module_t.common.module_api_version):
687      *
688      * CAMERA_MODULE_API_VERSION_2_3 or lower:
689      *
690      *   The value here must be static, and cannot change after the first call
691      *   to this method.
692      *
693      * CAMERA_MODULE_API_VERSION_2_4 or higher:
694      *
695      *   The value here must be static, and must count only built-in cameras,
696      *   which have CAMERA_FACING_BACK or CAMERA_FACING_FRONT camera facing values
697      *   (camera_info.facing). The HAL must not include the external cameras
698      *   (camera_info.facing == CAMERA_FACING_EXTERNAL) into the return value
699      *   of this call. Frameworks will use camera_device_status_change callback
700      *   to manage number of external cameras.
701      */
702     int (*get_number_of_cameras)(void);
703 
704     /**
705      * get_camera_info:
706      *
707      * Return the static camera information for a given camera device. This
708      * information may not change for a camera device.
709      *
710      * Return values:
711      *
712      * 0:           On a successful operation
713      *
714      * -ENODEV:     The information cannot be provided due to an internal
715      *              error.
716      *
717      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
718      *              and/or the module is invalid.
719      *
720      * Version information (based on camera_module_t.common.module_api_version):
721      *
722      * CAMERA_MODULE_API_VERSION_2_4 or higher:
723      *
724      *   When a camera is disconnected, its camera id becomes invalid. Calling this
725      *   this method with this invalid camera id will get -EINVAL and NULL camera
726      *   static metadata (camera_info.static_camera_characteristics).
727      */
728     int (*get_camera_info)(int camera_id, struct camera_info *info);
729 
730     /**
731      * set_callbacks:
732      *
733      * Provide callback function pointers to the HAL module to inform framework
734      * of asynchronous camera module events. The framework will call this
735      * function once after initial camera HAL module load, after the
736      * get_number_of_cameras() method is called for the first time, and before
737      * any other calls to the module.
738      *
739      * Version information (based on camera_module_t.common.module_api_version):
740      *
741      *  CAMERA_MODULE_API_VERSION_1_0, CAMERA_MODULE_API_VERSION_2_0:
742      *
743      *    Not provided by HAL module. Framework may not call this function.
744      *
745      *  CAMERA_MODULE_API_VERSION_2_1:
746      *
747      *    Valid to be called by the framework.
748      *
749      * Return values:
750      *
751      * 0:           On a successful operation
752      *
753      * -ENODEV:     The operation cannot be completed due to an internal
754      *              error.
755      *
756      * -EINVAL:     The input arguments are invalid, i.e. the callbacks are
757      *              null
758      */
759     int (*set_callbacks)(const camera_module_callbacks_t *callbacks);
760 
761     /**
762      * get_vendor_tag_ops:
763      *
764      * Get methods to query for vendor extension metadata tag information. The
765      * HAL should fill in all the vendor tag operation methods, or leave ops
766      * unchanged if no vendor tags are defined.
767      *
768      * The vendor_tag_ops structure used here is defined in:
769      * system/media/camera/include/system/vendor_tags.h
770      *
771      * Version information (based on camera_module_t.common.module_api_version):
772      *
773      *  CAMERA_MODULE_API_VERSION_1_x/2_0/2_1:
774      *    Not provided by HAL module. Framework may not call this function.
775      *
776      *  CAMERA_MODULE_API_VERSION_2_2:
777      *    Valid to be called by the framework.
778      */
779     void (*get_vendor_tag_ops)(vendor_tag_ops_t* ops);
780 
781     /**
782      * open_legacy:
783      *
784      * Open a specific legacy camera HAL device if multiple device HAL API
785      * versions are supported by this camera HAL module. For example, if the
786      * camera module supports both CAMERA_DEVICE_API_VERSION_1_0 and
787      * CAMERA_DEVICE_API_VERSION_3_2 device API for the same camera id,
788      * framework can call this function to open the camera device as
789      * CAMERA_DEVICE_API_VERSION_1_0 device.
790      *
791      * This is an optional method. A Camera HAL module does not need to support
792      * more than one device HAL version per device, and such modules may return
793      * -ENOSYS for all calls to this method. For all older HAL device API
794      * versions that are not supported, it may return -EOPNOTSUPP. When above
795      * cases occur, The normal open() method (common.methods->open) will be
796      * used by the framework instead.
797      *
798      * Version information (based on camera_module_t.common.module_api_version):
799      *
800      *  CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2:
801      *    Not provided by HAL module. Framework will not call this function.
802      *
803      *  CAMERA_MODULE_API_VERSION_2_3:
804      *    Valid to be called by the framework.
805      *
806      * Return values:
807      *
808      * 0:           On a successful open of the camera device.
809      *
810      * -ENOSYS      This method is not supported.
811      *
812      * -EOPNOTSUPP: The requested HAL version is not supported by this method.
813      *
814      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
815      *              and/or the module is invalid.
816      *
817      * -EBUSY:      The camera device was already opened for this camera id
818      *              (by using this method or common.methods->open method),
819      *              regardless of the device HAL version it was opened as.
820      *
821      * -EUSERS:     The maximal number of camera devices that can be
822      *              opened concurrently were opened already, either by
823      *              this method or common.methods->open method.
824      */
825     int (*open_legacy)(const struct hw_module_t* module, const char* id,
826             uint32_t halVersion, struct hw_device_t** device);
827 
828     /**
829      * set_torch_mode:
830      *
831      * Turn on or off the torch mode of the flash unit associated with a given
832      * camera ID. If the operation is successful, HAL must notify the framework
833      * torch state by invoking
834      * camera_module_callbacks.torch_mode_status_change() with the new state.
835      *
836      * The camera device has a higher priority accessing the flash unit. When
837      * there are any resource conflicts, such as open() is called to open a
838      * camera device, HAL module must notify the framework through
839      * camera_module_callbacks.torch_mode_status_change() that the
840      * torch mode has been turned off and the torch mode state has become
841      * TORCH_MODE_STATUS_NOT_AVAILABLE. When resources to turn on torch mode
842      * become available again, HAL module must notify the framework through
843      * camera_module_callbacks.torch_mode_status_change() that the torch mode
844      * state has become TORCH_MODE_STATUS_AVAILABLE_OFF for set_torch_mode() to
845      * be called.
846      *
847      * When the framework calls set_torch_mode() to turn on the torch mode of a
848      * flash unit, if HAL cannot keep multiple torch modes on simultaneously,
849      * HAL should turn off the torch mode that was turned on by
850      * a previous set_torch_mode() call and notify the framework that the torch
851      * mode state of that flash unit has become TORCH_MODE_STATUS_AVAILABLE_OFF.
852      *
853      * Version information (based on camera_module_t.common.module_api_version):
854      *
855      * CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2/2_3:
856      *   Not provided by HAL module. Framework will not call this function.
857      *
858      * CAMERA_MODULE_API_VERSION_2_4:
859      *   Valid to be called by the framework.
860      *
861      * Return values:
862      *
863      * 0:           On a successful operation.
864      *
865      * -ENOSYS:     The camera device does not support this operation. It is
866      *              returned if and only if android.flash.info.available is
867      *              false.
868      *
869      * -EBUSY:      The camera device is already in use.
870      *
871      * -EUSERS:     The resources needed to turn on the torch mode are not
872      *              available, typically because other camera devices are
873      *              holding the resources to make using the flash unit not
874      *              possible.
875      *
876      * -EINVAL:     camera_id is invalid.
877      *
878      */
879     int (*set_torch_mode)(const char* camera_id, bool enabled);
880 
881     /**
882      * init:
883      *
884      * This method is called by the camera service before any other methods
885      * are invoked, right after the camera HAL library has been successfully
886      * loaded. It may be left as NULL by the HAL module, if no initialization
887      * in needed.
888      *
889      * It can be used by HAL implementations to perform initialization and
890      * other one-time operations.
891      *
892      * Version information (based on camera_module_t.common.module_api_version):
893      *
894      * CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2/2_3:
895      *   Not provided by HAL module. Framework will not call this function.
896      *
897      * CAMERA_MODULE_API_VERSION_2_4:
898      *   If not NULL, will always be called by the framework once after the HAL
899      *   module is loaded, before any other HAL module method is called.
900      *
901      * Return values:
902      *
903      * 0:           On a successful operation.
904      *
905      * -ENODEV:     Initialization cannot be completed due to an internal
906      *              error. The HAL must be assumed to be in a nonfunctional
907      *              state.
908      *
909      */
910     int (*init)();
911 
912     /* reserved for future use */
913     void* reserved[5];
914 } camera_module_t;
915 
916 __END_DECLS
917 
918 #endif /* ANDROID_INCLUDE_CAMERA_COMMON_H */
919