From 85e89f2eaaf6e83bc08218e3df11de567de75a0e Mon Sep 17 00:00:00 2001
From: Rucha Katakwar <ruchamk@google.com>
Date: Tue, 12 Oct 2021 10:10:44 -0700
Subject: [PATCH] Camera: Add torch brightness control keys.

1.FLASH_INFO_STRENGTH_MAXIMUM_LEVEL : Number of brightness levels.
2.FLASH_INFO_STRENGTH_DEFAULT_LEVEL : Default brightness level for device in
TORCH mode.

The API to actually control the torch strength level and tests will be
added in the next series of changes.

bug: 200174275
Change-Id: I674885a237d734a2a45f40fa0e336b07fa649859
---
 core/api/current.txt                          |  2 ++
 .../camera2/CameraCharacteristics.java        | 36 +++++++++++++++++++
 .../hardware/camera2/CaptureRequest.java      |  3 +-
 3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/core/api/current.txt b/core/api/current.txt
index 454567d7dd699..7dbc68f97c5c7 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -18016,6 +18016,8 @@ package android.hardware.camera2 {
     field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<int[]> DISTORTION_CORRECTION_AVAILABLE_MODES;
     field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<int[]> EDGE_AVAILABLE_EDGE_MODES;
     field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<java.lang.Boolean> FLASH_INFO_AVAILABLE;
+    field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<java.lang.Integer> FLASH_INFO_STRENGTH_DEFAULT_LEVEL;
+    field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<java.lang.Integer> FLASH_INFO_STRENGTH_MAXIMUM_LEVEL;
     field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<int[]> HOT_PIXEL_AVAILABLE_HOT_PIXEL_MODES;
     field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<android.hardware.camera2.params.DeviceStateSensorOrientationMap> INFO_DEVICE_STATE_SENSOR_ORIENTATION_MAP;
     field @NonNull public static final android.hardware.camera2.CameraCharacteristics.Key<java.lang.Integer> INFO_SUPPORTED_HARDWARE_LEVEL;
diff --git a/core/java/android/hardware/camera2/CameraCharacteristics.java b/core/java/android/hardware/camera2/CameraCharacteristics.java
index 9f77a7e72e704..afea4e5f35e38 100644
--- a/core/java/android/hardware/camera2/CameraCharacteristics.java
+++ b/core/java/android/hardware/camera2/CameraCharacteristics.java
@@ -1319,6 +1319,42 @@ public final class CameraCharacteristics extends CameraMetadata<CameraCharacteri
     public static final Key<Boolean> FLASH_INFO_AVAILABLE =
             new Key<Boolean>("android.flash.info.available", boolean.class);
 
+    /**
+     * <p>Maximum flashlight brightness level.</p>
+     * <p>If this value is greater than 1, then the device supports controlling the
+     * flashlight brightness level via
+     * {android.hardware.camera2.CameraManager#setTorchStrengthLevel}.
+     * If this value is equal to 1, flashlight brightness control is not supported.
+     * This value will be -1 if the flash unit is not available.</p>
+     * <p><b>Optional</b> - The value for this key may be {@code null} on some devices.</p>
+     */
+    @PublicKey
+    @NonNull
+    public static final Key<Integer> FLASH_INFO_STRENGTH_MAXIMUM_LEVEL =
+            new Key<Integer>("android.flash.info.strengthMaximumLevel", int.class);
+
+    /**
+     * <p>Default flashlight brightness level to be set via
+     * {android.hardware.camera2.CameraManager#setTorchStrengthLevel}.</p>
+     * <p>If flash unit is available this will be greater than or equal to 1 and less
+     * or equal to <code>{@link CameraCharacteristics#FLASH_INFO_STRENGTH_MAXIMUM_LEVEL android.flash.info.strengthMaximumLevel}</code>.
+     * If flash unit is not available this will be set to -1.</p>
+     * <p>Setting flashlight brightness above the default level
+     * (i.e.<code>{@link CameraCharacteristics#FLASH_INFO_STRENGTH_DEFAULT_LEVEL android.flash.info.strengthDefaultLevel}</code>) may make the device more
+     * likely to reach thermal throttling conditions and slow down, or drain the
+     * battery quicker than normal. To minimize such issues, it is recommended to
+     * start the flashlight at this default brightness until a user explicitly requests
+     * a brighter level.</p>
+     * <p><b>Optional</b> - The value for this key may be {@code null} on some devices.</p>
+     *
+     * @see CameraCharacteristics#FLASH_INFO_STRENGTH_DEFAULT_LEVEL
+     * @see CameraCharacteristics#FLASH_INFO_STRENGTH_MAXIMUM_LEVEL
+     */
+    @PublicKey
+    @NonNull
+    public static final Key<Integer> FLASH_INFO_STRENGTH_DEFAULT_LEVEL =
+            new Key<Integer>("android.flash.info.strengthDefaultLevel", int.class);
+
     /**
      * <p>List of hot pixel correction modes for {@link CaptureRequest#HOT_PIXEL_MODE android.hotPixel.mode} that are supported by this
      * camera device.</p>
diff --git a/core/java/android/hardware/camera2/CaptureRequest.java b/core/java/android/hardware/camera2/CaptureRequest.java
index 027681538ce5a..08276ac230326 100644
--- a/core/java/android/hardware/camera2/CaptureRequest.java
+++ b/core/java/android/hardware/camera2/CaptureRequest.java
@@ -1022,8 +1022,7 @@ public final class CaptureRequest extends CameraMetadata<CaptureRequest.Key<?>>
      * <p>which define a transform from input sensor colors, <code>P_in = [ r g b ]</code>,
      * to output linear sRGB, <code>P_out = [ r' g' b' ]</code>,</p>
      * <p>with colors as follows:</p>
-     * <pre><code>
-     * r' = I0r + I1g + I2b
+     * <pre><code>r' = I0r + I1g + I2b
      * g' = I3r + I4g + I5b
      * b' = I6r + I7g + I8b
      * </code></pre>