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 
152 // Device version 3.4 is current, older HAL camera device versions are not
153 // recommended for new devices.
154 #define CAMERA_DEVICE_API_VERSION_CURRENT CAMERA_DEVICE_API_VERSION_3_4
155 
156 /**
157  * Defined in /system/media/camera/include/system/camera_metadata.h
158  */
159 typedef struct camera_metadata camera_metadata_t;
160 
161 typedef struct camera_info {
162     /**
163      * The direction that the camera faces to. See system/core/include/system/camera.h
164      * for camera facing definitions.
165      *
166      * Version information (based on camera_module_t.common.module_api_version):
167      *
168      * CAMERA_MODULE_API_VERSION_2_3 or lower:
169      *
170      *   It should be CAMERA_FACING_BACK or CAMERA_FACING_FRONT.
171      *
172      * CAMERA_MODULE_API_VERSION_2_4 or higher:
173      *
174      *   It should be CAMERA_FACING_BACK, CAMERA_FACING_FRONT or
175      *   CAMERA_FACING_EXTERNAL.
176      */
177     int facing;
178 
179     /**
180      * The orientation of the camera image. The value is the angle that the
181      * camera image needs to be rotated clockwise so it shows correctly on the
182      * display in its natural orientation. It should be 0, 90, 180, or 270.
183      *
184      * For example, suppose a device has a naturally tall screen. The
185      * back-facing camera sensor is mounted in landscape. You are looking at the
186      * screen. If the top side of the camera sensor is aligned with the right
187      * edge of the screen in natural orientation, the value should be 90. If the
188      * top side of a front-facing camera sensor is aligned with the right of the
189      * screen, the value should be 270.
190      *
191      * Version information (based on camera_module_t.common.module_api_version):
192      *
193      * CAMERA_MODULE_API_VERSION_2_3 or lower:
194      *
195      *   Valid in all camera_module versions.
196      *
197      * CAMERA_MODULE_API_VERSION_2_4 or higher:
198      *
199      *   Valid if camera facing is CAMERA_FACING_BACK or CAMERA_FACING_FRONT,
200      *   not valid if camera facing is CAMERA_FACING_EXTERNAL.
201      */
202     int orientation;
203 
204     /**
205      * The value of camera_device_t.common.version.
206      *
207      * Version information (based on camera_module_t.common.module_api_version):
208      *
209      *  CAMERA_MODULE_API_VERSION_1_0:
210      *
211      *    Not valid. Can be assumed to be CAMERA_DEVICE_API_VERSION_1_0. Do
212      *    not read this field.
213      *
214      *  CAMERA_MODULE_API_VERSION_2_0 or higher:
215      *
216      *    Always valid
217      *
218      */
219     uint32_t device_version;
220 
221     /**
222      * The camera's fixed characteristics, which include all static camera metadata
223      * specified in system/media/camera/docs/docs.html. This should be a sorted metadata
224      * buffer, and may not be modified or freed by the caller. The pointer should remain
225      * valid for the lifetime of the camera module, and values in it may not
226      * change after it is returned by get_camera_info().
227      *
228      * Version information (based on camera_module_t.common.module_api_version):
229      *
230      *  CAMERA_MODULE_API_VERSION_1_0:
231      *
232      *    Not valid. Extra characteristics are not available. Do not read this
233      *    field.
234      *
235      *  CAMERA_MODULE_API_VERSION_2_0 or higher:
236      *
237      *    Valid if device_version >= CAMERA_DEVICE_API_VERSION_2_0. Do not read
238      *    otherwise.
239      *
240      */
241     const camera_metadata_t *static_camera_characteristics;
242 
243     /**
244      * The total resource "cost" of using this camera, represented as an integer
245      * value in the range [0, 100] where 100 represents total usage of the shared
246      * resource that is the limiting bottleneck of the camera subsystem.  This may
247      * be a very rough estimate, and is used as a hint to the camera service to
248      * determine when to disallow multiple applications from simultaneously
249      * opening different cameras advertised by the camera service.
250      *
251      * The camera service must be able to simultaneously open and use any
252      * combination of camera devices exposed by the HAL where the sum of
253      * the resource costs of these cameras is <= 100.  For determining cost,
254      * each camera device must be assumed to be configured and operating at
255      * the maximally resource-consuming framerate and stream size settings
256      * available in the configuration settings exposed for that device through
257      * the camera metadata.
258      *
259      * The camera service may still attempt to simultaneously open combinations
260      * of camera devices with a total resource cost > 100.  This may succeed or
261      * fail.  If this succeeds, combinations of configurations that are not
262      * supported due to resource constraints from having multiple open devices
263      * should fail during the configure calls.  If the total resource cost is
264      * <= 100, open and configure should never fail for any stream configuration
265      * settings or other device capabilities that would normally succeed for a
266      * device when it is the only open camera device.
267      *
268      * This field will be used to determine whether background applications are
269      * allowed to use this camera device while other applications are using other
270      * camera devices.  Note: multiple applications will never be allowed by the
271      * camera service to simultaneously open the same camera device.
272      *
273      * Example use cases:
274      *
275      * Ex. 1: Camera Device 0 = Back Camera
276      *        Camera Device 1 = Front Camera
277      *   - Using both camera devices causes a large framerate slowdown due to
278      *     limited ISP bandwidth.
279      *
280      *   Configuration:
281      *
282      *   Camera Device 0 - resource_cost = 51
283      *                     conflicting_devices = null
284      *   Camera Device 1 - resource_cost = 51
285      *                     conflicting_devices = null
286      *
287      *   Result:
288      *
289      *   Since the sum of the resource costs is > 100, if a higher-priority
290      *   application has either device open, no lower-priority applications will be
291      *   allowed by the camera service to open either device.  If a lower-priority
292      *   application is using a device that a higher-priority subsequently attempts
293      *   to open, the lower-priority application will be forced to disconnect the
294      *   the device.
295      *
296      *   If the highest-priority application chooses, it may still attempt to open
297      *   both devices (since these devices are not listed as conflicting in the
298      *   conflicting_devices fields), but usage of these devices may fail in the
299      *   open or configure calls.
300      *
301      * Ex. 2: Camera Device 0 = Left Back Camera
302      *        Camera Device 1 = Right Back Camera
303      *        Camera Device 2 = Combined stereo camera using both right and left
304      *                          back camera sensors used by devices 0, and 1
305      *        Camera Device 3 = Front Camera
306      *   - Due to do hardware constraints, up to two cameras may be open at once. The
307      *     combined stereo camera may never be used at the same time as either of the
308      *     two back camera devices (device 0, 1), and typically requires too much
309      *     bandwidth to use at the same time as the front camera (device 3).
310      *
311      *   Configuration:
312      *
313      *   Camera Device 0 - resource_cost = 50
314      *                     conflicting_devices = { 2 }
315      *   Camera Device 1 - resource_cost = 50
316      *                     conflicting_devices = { 2 }
317      *   Camera Device 2 - resource_cost = 100
318      *                     conflicting_devices = { 0, 1 }
319      *   Camera Device 3 - resource_cost = 50
320      *                     conflicting_devices = null
321      *
322      *   Result:
323      *
324      *   Based on the conflicting_devices fields, the camera service guarantees that
325      *   the following sets of open devices will never be allowed: { 1, 2 }, { 0, 2 }.
326      *
327      *   Based on the resource_cost fields, if a high-priority foreground application
328      *   is using camera device 0, a background application would be allowed to open
329      *   camera device 1 or 3 (but would be forced to disconnect it again if the
330      *   foreground application opened another device).
331      *
332      *   The highest priority application may still attempt to simultaneously open
333      *   devices 0, 2, and 3, but the HAL may fail in open or configure calls for
334      *   this combination.
335      *
336      * Ex. 3: Camera Device 0 = Back Camera
337      *        Camera Device 1 = Front Camera
338      *        Camera Device 2 = Low-power Front Camera that uses the same
339      *                          sensor as device 1, but only exposes image stream
340      *                          resolutions that can be used in low-power mode
341      *  - Using both front cameras (device 1, 2) at the same time is impossible due
342      *    a shared physical sensor.  Using the back and "high-power" front camera
343      *    (device 1) may be impossible for some stream configurations due to hardware
344      *    limitations, but the "low-power" front camera option may always be used as
345      *    it has special dedicated hardware.
346      *
347      *   Configuration:
348      *
349      *   Camera Device 0 - resource_cost = 100
350      *                     conflicting_devices = null
351      *   Camera Device 1 - resource_cost = 100
352      *                     conflicting_devices = { 2 }
353      *   Camera Device 2 - resource_cost = 0
354      *                     conflicting_devices = { 1 }
355      *   Result:
356      *
357      *   Based on the conflicting_devices fields, the camera service guarantees that
358      *   the following sets of open devices will never be allowed: { 1, 2 }.
359      *
360      *   Based on the resource_cost fields, only the highest priority application
361      *   may attempt to open both device 0 and 1 at the same time. If a higher-priority
362      *   application is not using device 1 or 2, a low-priority background application
363      *   may open device 2 (but will be forced to disconnect it if a higher-priority
364      *   application subsequently opens device 1 or 2).
365      *
366      * Version information (based on camera_module_t.common.module_api_version):
367      *
368      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
369      *
370      *    Not valid.  Can be assumed to be 100.  Do not read this field.
371      *
372      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
373      *
374      *    Always valid.
375      */
376     int resource_cost;
377 
378     /**
379      * An array of camera device IDs represented as NULL-terminated strings
380      * indicating other devices that cannot be simultaneously opened while this
381      * camera device is in use.
382      *
383      * This field is intended to be used to indicate that this camera device
384      * is a composite of several other camera devices, or otherwise has
385      * hardware dependencies that prohibit simultaneous usage. If there are no
386      * dependencies, a NULL may be returned in this field to indicate this.
387      *
388      * The camera service will never simultaneously open any of the devices
389      * in this list while this camera device is open.
390      *
391      * The strings pointed to in this field will not be cleaned up by the camera
392      * service, and must remain while this device is plugged in.
393      *
394      * Version information (based on camera_module_t.common.module_api_version):
395      *
396      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
397      *
398      *    Not valid.  Can be assumed to be NULL.  Do not read this field.
399      *
400      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
401      *
402      *    Always valid.
403      */
404     char** conflicting_devices;
405 
406     /**
407      * The length of the array given in the conflicting_devices field.
408      *
409      * Version information (based on camera_module_t.common.module_api_version):
410      *
411      *  CAMERA_MODULE_API_VERSION_2_3 or lower:
412      *
413      *    Not valid.  Can be assumed to be 0.  Do not read this field.
414      *
415      *  CAMERA_MODULE_API_VERSION_2_4 or higher:
416      *
417      *    Always valid.
418      */
419     size_t conflicting_devices_length;
420 
421 } camera_info_t;
422 
423 /**
424  * camera_device_status_t:
425  *
426  * The current status of the camera device, as provided by the HAL through the
427  * camera_module_callbacks.camera_device_status_change() call.
428  *
429  * At module load time, the framework will assume all camera devices are in the
430  * CAMERA_DEVICE_STATUS_PRESENT state. The HAL should invoke
431  * camera_module_callbacks::camera_device_status_change to inform the framework
432  * of any initially NOT_PRESENT devices.
433  *
434  * Allowed transitions:
435  *      PRESENT            -> NOT_PRESENT
436  *      NOT_PRESENT        -> ENUMERATING
437  *      NOT_PRESENT        -> PRESENT
438  *      ENUMERATING        -> PRESENT
439  *      ENUMERATING        -> NOT_PRESENT
440  */
441 typedef enum camera_device_status {
442     /**
443      * The camera device is not currently connected, and opening it will return
444      * failure.
445      *
446      * Version information (based on camera_module_t.common.module_api_version):
447      *
448      * CAMERA_MODULE_API_VERSION_2_3 or lower:
449      *
450      *   Calls to get_camera_info must still succeed, and provide the same information
451      *   it would if the camera were connected.
452      *
453      * CAMERA_MODULE_API_VERSION_2_4:
454      *
455      *   The camera device at this status must return -EINVAL for get_camera_info call,
456      *   as the device is not connected.
457      */
458     CAMERA_DEVICE_STATUS_NOT_PRESENT = 0,
459 
460     /**
461      * The camera device is connected, and opening it will succeed.
462      *
463      * CAMERA_MODULE_API_VERSION_2_3 or lower:
464      *
465      *   The information returned by get_camera_info cannot change due to this status
466      *   change. By default, the framework will assume all devices are in this state.
467      *
468      * CAMERA_MODULE_API_VERSION_2_4:
469      *
470      *   The information returned by get_camera_info will become valid after a device's
471      *   status changes to this. By default, the framework will assume all devices are in
472      *   this state.
473      */
474     CAMERA_DEVICE_STATUS_PRESENT = 1,
475 
476     /**
477      * The camera device is connected, but it is undergoing an enumeration and
478      * so opening the device will return -EBUSY.
479      *
480      * CAMERA_MODULE_API_VERSION_2_3 or lower:
481      *
482      *   Calls to get_camera_info must still succeed, as if the camera was in the
483      *   PRESENT status.
484      *
485      * CAMERA_MODULE_API_VERSION_2_4:
486      *
487      *   The camera device at this status must return -EINVAL for get_camera_info for call,
488      *   as the device is not ready.
489      */
490     CAMERA_DEVICE_STATUS_ENUMERATING = 2,
491 
492 } camera_device_status_t;
493 
494 /**
495  * torch_mode_status_t:
496  *
497  * The current status of the torch mode, as provided by the HAL through the
498  * camera_module_callbacks.torch_mode_status_change() call.
499  *
500  * The torch mode status of a camera device is applicable only when the camera
501  * device is present. The framework will not call set_torch_mode() to turn on
502  * torch mode of a camera device if the camera device is not present. At module
503  * load time, the framework will assume torch modes are in the
504  * TORCH_MODE_STATUS_AVAILABLE_OFF state if the camera device is present and
505  * android.flash.info.available is reported as true via get_camera_info() call.
506  *
507  * The behaviors of the camera HAL module that the framework expects in the
508  * following situations when a camera device's status changes:
509  *  1. A previously-disconnected camera device becomes connected.
510  *      After camera_module_callbacks::camera_device_status_change() is invoked
511  *      to inform the framework that the camera device is present, the framework
512  *      will assume the camera device's torch mode is in
513  *      TORCH_MODE_STATUS_AVAILABLE_OFF state. The camera HAL module does not need
514  *      to invoke camera_module_callbacks::torch_mode_status_change() unless the
515  *      flash unit is unavailable to use by set_torch_mode().
516  *
517  *  2. A previously-connected camera becomes disconnected.
518  *      After camera_module_callbacks::camera_device_status_change() is invoked
519  *      to inform the framework that the camera device is not present, the
520  *      framework will not call set_torch_mode() for the disconnected camera
521  *      device until its flash unit becomes available again. The camera HAL
522  *      module does not need to invoke
523  *      camera_module_callbacks::torch_mode_status_change() separately to inform
524  *      that the flash unit has become unavailable.
525  *
526  *  3. open() is called to open a camera device.
527  *      The camera HAL module must invoke
528  *      camera_module_callbacks::torch_mode_status_change() for all flash units
529  *      that have entered TORCH_MODE_STATUS_NOT_AVAILABLE state and can not be
530  *      turned on by calling set_torch_mode() anymore due to this open() call.
531  *      open() must not trigger TORCH_MODE_STATUS_AVAILABLE_OFF before
532  *      TORCH_MODE_STATUS_NOT_AVAILABLE for all flash units that have become
533  *      unavailable.
534  *
535  *  4. close() is called to close a camera device.
536  *      The camera HAL module must invoke
537  *      camera_module_callbacks::torch_mode_status_change() for all flash units
538  *      that have entered TORCH_MODE_STATUS_AVAILABLE_OFF state and can be turned
539  *      on by calling set_torch_mode() again because of enough resources freed
540  *      up by this close() call.
541  *
542  *  Note that the framework calling set_torch_mode() successfully must trigger
543  *  TORCH_MODE_STATUS_AVAILABLE_OFF or TORCH_MODE_STATUS_AVAILABLE_ON callback
544  *  for the given camera device. Additionally it must trigger
545  *  TORCH_MODE_STATUS_AVAILABLE_OFF callbacks for other previously-on torch
546  *  modes if HAL cannot keep multiple torch modes on simultaneously.
547  */
548 typedef enum torch_mode_status {
549 
550     /**
551      * The flash unit is no longer available and the torch mode can not be
552      * turned on by calling set_torch_mode(). If the torch mode is on, it
553      * will be turned off by HAL before HAL calls torch_mode_status_change().
554      */
555     TORCH_MODE_STATUS_NOT_AVAILABLE = 0,
556 
557     /**
558      * A torch mode has become off and available to be turned on via
559      * set_torch_mode(). This may happen in the following
560      * cases:
561      *   1. After the resources to turn on the torch mode have become available.
562      *   2. After set_torch_mode() is called to turn off the torch mode.
563      *   3. After the framework turned on the torch mode of some other camera
564      *      device and HAL had to turn off the torch modes of any camera devices
565      *      that were previously on.
566      */
567     TORCH_MODE_STATUS_AVAILABLE_OFF = 1,
568 
569     /**
570      * A torch mode has become on and available to be turned off via
571      * set_torch_mode(). This can happen only after set_torch_mode() is called
572      * to turn on the torch mode.
573      */
574     TORCH_MODE_STATUS_AVAILABLE_ON = 2,
575 
576 } torch_mode_status_t;
577 
578 /**
579  * Callback functions for the camera HAL module to use to inform the framework
580  * of changes to the camera subsystem.
581  *
582  * Version information (based on camera_module_t.common.module_api_version):
583  *
584  * Each callback is called only by HAL modules implementing the indicated
585  * version or higher of the HAL module API interface.
586  *
587  *  CAMERA_MODULE_API_VERSION_2_1:
588  *    camera_device_status_change()
589  *
590  *  CAMERA_MODULE_API_VERSION_2_4:
591  *    torch_mode_status_change()
592 
593  */
594 typedef struct camera_module_callbacks {
595 
596     /**
597      * camera_device_status_change:
598      *
599      * Callback to the framework to indicate that the state of a specific camera
600      * device has changed. At module load time, the framework will assume all
601      * camera devices are in the CAMERA_DEVICE_STATUS_PRESENT state. The HAL
602      * must call this method to inform the framework of any initially
603      * NOT_PRESENT devices.
604      *
605      * This callback is added for CAMERA_MODULE_API_VERSION_2_1.
606      *
607      * camera_module_callbacks: The instance of camera_module_callbacks_t passed
608      *   to the module with set_callbacks.
609      *
610      * camera_id: The ID of the camera device that has a new status.
611      *
612      * new_status: The new status code, one of the camera_device_status_t enums,
613      *   or a platform-specific status.
614      *
615      */
616     void (*camera_device_status_change)(const struct camera_module_callbacks*,
617             int camera_id,
618             int new_status);
619 
620     /**
621      * torch_mode_status_change:
622      *
623      * Callback to the framework to indicate that the state of the torch mode
624      * of the flash unit associated with a specific camera device has changed.
625      * At module load time, the framework will assume the torch modes are in
626      * the TORCH_MODE_STATUS_AVAILABLE_OFF state if android.flash.info.available
627      * is reported as true via get_camera_info() call.
628      *
629      * This callback is added for CAMERA_MODULE_API_VERSION_2_4.
630      *
631      * camera_module_callbacks: The instance of camera_module_callbacks_t
632      *   passed to the module with set_callbacks.
633      *
634      * camera_id: The ID of camera device whose flash unit has a new torch mode
635      *   status.
636      *
637      * new_status: The new status code, one of the torch_mode_status_t enums.
638      */
639     void (*torch_mode_status_change)(const struct camera_module_callbacks*,
640             const char* camera_id,
641             int new_status);
642 
643 
644 } camera_module_callbacks_t;
645 
646 typedef struct camera_module {
647     /**
648      * Common methods of the camera module.  This *must* be the first member of
649      * camera_module as users of this structure will cast a hw_module_t to
650      * camera_module pointer in contexts where it's known the hw_module_t
651      * references a camera_module.
652      *
653      * The return values for common.methods->open for camera_module are:
654      *
655      * 0:           On a successful open of the camera device.
656      *
657      * -ENODEV:     The camera device cannot be opened due to an internal
658      *              error.
659      *
660      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
661      *              and/or the module is invalid.
662      *
663      * -EBUSY:      The camera device was already opened for this camera id
664      *              (by using this method or open_legacy),
665      *              regardless of the device HAL version it was opened as.
666      *
667      * -EUSERS:     The maximal number of camera devices that can be
668      *              opened concurrently were opened already, either by
669      *              this method or the open_legacy method.
670      *
671      * All other return values from common.methods->open will be treated as
672      * -ENODEV.
673      */
674     hw_module_t common;
675 
676     /**
677      * get_number_of_cameras:
678      *
679      * Returns the number of camera devices accessible through the camera
680      * module.  The camera devices are numbered 0 through N-1, where N is the
681      * value returned by this call. The name of the camera device for open() is
682      * simply the number converted to a string. That is, "0" for camera ID 0,
683      * "1" for camera ID 1.
684      *
685      * Version information (based on camera_module_t.common.module_api_version):
686      *
687      * CAMERA_MODULE_API_VERSION_2_3 or lower:
688      *
689      *   The value here must be static, and cannot change after the first call
690      *   to this method.
691      *
692      * CAMERA_MODULE_API_VERSION_2_4 or higher:
693      *
694      *   The value here must be static, and must count only built-in cameras,
695      *   which have CAMERA_FACING_BACK or CAMERA_FACING_FRONT camera facing values
696      *   (camera_info.facing). The HAL must not include the external cameras
697      *   (camera_info.facing == CAMERA_FACING_EXTERNAL) into the return value
698      *   of this call. Frameworks will use camera_device_status_change callback
699      *   to manage number of external cameras.
700      */
701     int (*get_number_of_cameras)(void);
702 
703     /**
704      * get_camera_info:
705      *
706      * Return the static camera information for a given camera device. This
707      * information may not change for a camera device.
708      *
709      * Return values:
710      *
711      * 0:           On a successful operation
712      *
713      * -ENODEV:     The information cannot be provided due to an internal
714      *              error.
715      *
716      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
717      *              and/or the module is invalid.
718      *
719      * Version information (based on camera_module_t.common.module_api_version):
720      *
721      * CAMERA_MODULE_API_VERSION_2_4 or higher:
722      *
723      *   When a camera is disconnected, its camera id becomes invalid. Calling this
724      *   this method with this invalid camera id will get -EINVAL and NULL camera
725      *   static metadata (camera_info.static_camera_characteristics).
726      */
727     int (*get_camera_info)(int camera_id, struct camera_info *info);
728 
729     /**
730      * set_callbacks:
731      *
732      * Provide callback function pointers to the HAL module to inform framework
733      * of asynchronous camera module events. The framework will call this
734      * function once after initial camera HAL module load, after the
735      * get_number_of_cameras() method is called for the first time, and before
736      * any other calls to the module.
737      *
738      * Version information (based on camera_module_t.common.module_api_version):
739      *
740      *  CAMERA_MODULE_API_VERSION_1_0, CAMERA_MODULE_API_VERSION_2_0:
741      *
742      *    Not provided by HAL module. Framework may not call this function.
743      *
744      *  CAMERA_MODULE_API_VERSION_2_1:
745      *
746      *    Valid to be called by the framework.
747      *
748      * Return values:
749      *
750      * 0:           On a successful operation
751      *
752      * -ENODEV:     The operation cannot be completed due to an internal
753      *              error.
754      *
755      * -EINVAL:     The input arguments are invalid, i.e. the callbacks are
756      *              null
757      */
758     int (*set_callbacks)(const camera_module_callbacks_t *callbacks);
759 
760     /**
761      * get_vendor_tag_ops:
762      *
763      * Get methods to query for vendor extension metadata tag information. The
764      * HAL should fill in all the vendor tag operation methods, or leave ops
765      * unchanged if no vendor tags are defined.
766      *
767      * The vendor_tag_ops structure used here is defined in:
768      * system/media/camera/include/system/vendor_tags.h
769      *
770      * Version information (based on camera_module_t.common.module_api_version):
771      *
772      *  CAMERA_MODULE_API_VERSION_1_x/2_0/2_1:
773      *    Not provided by HAL module. Framework may not call this function.
774      *
775      *  CAMERA_MODULE_API_VERSION_2_2:
776      *    Valid to be called by the framework.
777      */
778     void (*get_vendor_tag_ops)(vendor_tag_ops_t* ops);
779 
780     /**
781      * open_legacy:
782      *
783      * Open a specific legacy camera HAL device if multiple device HAL API
784      * versions are supported by this camera HAL module. For example, if the
785      * camera module supports both CAMERA_DEVICE_API_VERSION_1_0 and
786      * CAMERA_DEVICE_API_VERSION_3_2 device API for the same camera id,
787      * framework can call this function to open the camera device as
788      * CAMERA_DEVICE_API_VERSION_1_0 device.
789      *
790      * This is an optional method. A Camera HAL module does not need to support
791      * more than one device HAL version per device, and such modules may return
792      * -ENOSYS for all calls to this method. For all older HAL device API
793      * versions that are not supported, it may return -EOPNOTSUPP. When above
794      * cases occur, The normal open() method (common.methods->open) will be
795      * used by the framework instead.
796      *
797      * Version information (based on camera_module_t.common.module_api_version):
798      *
799      *  CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2:
800      *    Not provided by HAL module. Framework will not call this function.
801      *
802      *  CAMERA_MODULE_API_VERSION_2_3:
803      *    Valid to be called by the framework.
804      *
805      * Return values:
806      *
807      * 0:           On a successful open of the camera device.
808      *
809      * -ENOSYS      This method is not supported.
810      *
811      * -EOPNOTSUPP: The requested HAL version is not supported by this method.
812      *
813      * -EINVAL:     The input arguments are invalid, i.e. the id is invalid,
814      *              and/or the module is invalid.
815      *
816      * -EBUSY:      The camera device was already opened for this camera id
817      *              (by using this method or common.methods->open method),
818      *              regardless of the device HAL version it was opened as.
819      *
820      * -EUSERS:     The maximal number of camera devices that can be
821      *              opened concurrently were opened already, either by
822      *              this method or common.methods->open method.
823      */
824     int (*open_legacy)(const struct hw_module_t* module, const char* id,
825             uint32_t halVersion, struct hw_device_t** device);
826 
827     /**
828      * set_torch_mode:
829      *
830      * Turn on or off the torch mode of the flash unit associated with a given
831      * camera ID. If the operation is successful, HAL must notify the framework
832      * torch state by invoking
833      * camera_module_callbacks.torch_mode_status_change() with the new state.
834      *
835      * The camera device has a higher priority accessing the flash unit. When
836      * there are any resource conflicts, such as open() is called to open a
837      * camera device, HAL module must notify the framework through
838      * camera_module_callbacks.torch_mode_status_change() that the
839      * torch mode has been turned off and the torch mode state has become
840      * TORCH_MODE_STATUS_NOT_AVAILABLE. When resources to turn on torch mode
841      * become available again, HAL module must notify the framework through
842      * camera_module_callbacks.torch_mode_status_change() that the torch mode
843      * state has become TORCH_MODE_STATUS_AVAILABLE_OFF for set_torch_mode() to
844      * be called.
845      *
846      * When the framework calls set_torch_mode() to turn on the torch mode of a
847      * flash unit, if HAL cannot keep multiple torch modes on simultaneously,
848      * HAL should turn off the torch mode that was turned on by
849      * a previous set_torch_mode() call and notify the framework that the torch
850      * mode state of that flash unit has become TORCH_MODE_STATUS_AVAILABLE_OFF.
851      *
852      * Version information (based on camera_module_t.common.module_api_version):
853      *
854      * CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2/2_3:
855      *   Not provided by HAL module. Framework will not call this function.
856      *
857      * CAMERA_MODULE_API_VERSION_2_4:
858      *   Valid to be called by the framework.
859      *
860      * Return values:
861      *
862      * 0:           On a successful operation.
863      *
864      * -ENOSYS:     The camera device does not support this operation. It is
865      *              returned if and only if android.flash.info.available is
866      *              false.
867      *
868      * -EBUSY:      The camera device is already in use.
869      *
870      * -EUSERS:     The resources needed to turn on the torch mode are not
871      *              available, typically because other camera devices are
872      *              holding the resources to make using the flash unit not
873      *              possible.
874      *
875      * -EINVAL:     camera_id is invalid.
876      *
877      */
878     int (*set_torch_mode)(const char* camera_id, bool enabled);
879 
880     /**
881      * init:
882      *
883      * This method is called by the camera service before any other methods
884      * are invoked, right after the camera HAL library has been successfully
885      * loaded. It may be left as NULL by the HAL module, if no initialization
886      * in needed.
887      *
888      * It can be used by HAL implementations to perform initialization and
889      * other one-time operations.
890      *
891      * Version information (based on camera_module_t.common.module_api_version):
892      *
893      * CAMERA_MODULE_API_VERSION_1_x/2_0/2_1/2_2/2_3:
894      *   Not provided by HAL module. Framework will not call this function.
895      *
896      * CAMERA_MODULE_API_VERSION_2_4:
897      *   If not NULL, will always be called by the framework once after the HAL
898      *   module is loaded, before any other HAL module method is called.
899      *
900      * Return values:
901      *
902      * 0:           On a successful operation.
903      *
904      * -ENODEV:     Initialization cannot be completed due to an internal
905      *              error. The HAL must be assumed to be in a nonfunctional
906      *              state.
907      *
908      */
909     int (*init)();
910 
911     /* reserved for future use */
912     void* reserved[5];
913 } camera_module_t;
914 
915 __END_DECLS
916 
917 #endif /* ANDROID_INCLUDE_CAMERA_COMMON_H */
918