[media] V4L: Add an extended camera white balance control

This patch adds V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE control which is
an extended version of the V4L2_CID_AUTO_WHITE_BALANCE control,
including white balance presets. The following presets are defined:

 - V4L2_WHITE_BALANCE_INCANDESCENT,
 - V4L2_WHITE_BALANCE_FLUORESCENT,
 - V4L2_WHITE_BALANCE_FLUORESCENT_H,
 - V4L2_WHITE_BALANCE_HORIZON,
 - V4L2_WHITE_BALANCE_DAYLIGHT,
 - V4L2_WHITE_BALANCE_FLASH,
 - V4L2_WHITE_BALANCE_CLOUDY,
 - V4L2_WHITE_BALANCE_SHADE.

Signed-off-by: HeungJun Kim <riverful.kim@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 101 insertions, 0 deletions

diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml
index 745b611c3593..56dfdf02c76b 100644
--- a/Documentation/DocBook/media/v4l/controls.xml
+++ b/Documentation/DocBook/media/v4l/controls.xml
@@ -3022,6 +3022,76 @@ camera sensor on or off, or specify its strength. Such band-stop filters can
 be used, for example, to filter out the fluorescent light component.</entry>
           </row>
           <row><entry></entry></row>
+
+          <row id="v4l2-auto-n-preset-white-balance">
+            <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant>&nbsp;</entry>
+            <entry>enum&nbsp;v4l2_auto_n_preset_white_balance</entry>
+          </row><row><entry spanname="descr">Sets white balance to automatic,
+manual or a preset. The presets determine color temperature of the light as
+a hint to the camera for white balance adjustments resulting in most accurate
+color representation. The following white balance presets are listed in order
+of increasing color temperature.</entry>
+          </row>
+          <row>
+            <entrytbl spanname="descr" cols="2">
+              <tbody valign="top">
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant>&nbsp;</entry>
+                  <entry>Manual white balance.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant>&nbsp;</entry>
+                  <entry>Automatic white balance adjustments.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant>&nbsp;</entry>
+                  <entry>White balance setting for incandescent (tungsten) lighting.
+It generally cools down the colors and corresponds approximately to 2500...3500 K
+color temperature range.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant>&nbsp;</entry>
+                  <entry>White balance preset for fluorescent lighting.
+It corresponds approximately to 4000...5000 K color temperature.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant>&nbsp;</entry>
+                  <entry>With this setting the camera will compensate for
+fluorescent H lighting.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant>&nbsp;</entry>
+                  <entry>White balance setting for horizon daylight.
+It corresponds approximately to 5000 K color temperature.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant>&nbsp;</entry>
+                  <entry>White balance preset for daylight (with clear sky).
+It corresponds approximately to 5000...6500 K color temperature.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant>&nbsp;</entry>
+                  <entry>With this setting the camera will compensate for the flash
+light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
+color temperature.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant>&nbsp;</entry>
+                  <entry>White balance preset for moderately overcast sky.
+This option corresponds approximately to 6500...8000 K color temperature
+range.</entry>
+                </row>
+                <row>
+                  <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant>&nbsp;</entry>
+                  <entry>White balance preset for shade or heavily overcast
+sky. It corresponds approximately to 9000...10000 K color temperature.
+</entry>
+                </row>
+              </tbody>
+            </entrytbl>
+          </row>
+          <row><entry></entry></row>
+
         </tbody>
       </tgroup>
     </table>
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index 5bfef90e88ee..56ac71c8ba37 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -249,6 +249,19 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
                 "Set Cb/Cr",
                 NULL
         };
+        static const char * const auto_n_preset_white_balance[] = {
+                "Manual",
+                "Auto",
+                "Incandescent",
+                "Fluorescent",
+                "Fluorescent H",
+                "Horizon",
+                "Daylight",
+                "Flash",
+                "Cloudy",
+                "Shade",
+                NULL,
+        };
         static const char * const tune_preemphasis[] = {
                 "No Preemphasis",
                 "50 Microseconds",
@@ -418,6 +431,8 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
                 return camera_exposure_auto;
         case V4L2_CID_COLORFX:
                 return colorfx;
+        case V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE:
+                return auto_n_preset_white_balance;
         case V4L2_CID_TUNE_PREEMPHASIS:
                 return tune_preemphasis;
         case V4L2_CID_FLASH_LED_MODE:
@@ -605,6 +620,7 @@ const char *v4l2_ctrl_get_name(u32 id)
         case V4L2_CID_IRIS_ABSOLUTE:            return "Iris, Absolute";
         case V4L2_CID_IRIS_RELATIVE:            return "Iris, Relative";
         case V4L2_CID_AUTO_EXPOSURE_BIAS:       return "Auto Exposure, Bias";
+        case V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE: return "White Balance, Auto & Preset";
 
         /* FM Radio Modulator control */
         /* Keep the order of the 'case's the same as in videodev2.h! */
@@ -739,6 +755,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
         case V4L2_CID_MPEG_STREAM_VBI_FMT:
         case V4L2_CID_EXPOSURE_AUTO:
         case V4L2_CID_COLORFX:
+        case V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE:
         case V4L2_CID_TUNE_PREEMPHASIS:
         case V4L2_CID_FLASH_LED_MODE:
         case V4L2_CID_FLASH_STROBE_SOURCE:
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index dfd209816df6..85c4e8f1090f 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -1709,6 +1709,20 @@ enum  v4l2_exposure_auto_type {
 
 #define V4L2_CID_AUTO_EXPOSURE_BIAS             (V4L2_CID_CAMERA_CLASS_BASE+19)
 
+#define V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE    (V4L2_CID_CAMERA_CLASS_BASE+20)
+enum v4l2_auto_n_preset_white_balance {
+        V4L2_WHITE_BALANCE_MANUAL               = 0,
+        V4L2_WHITE_BALANCE_AUTO                 = 1,
+        V4L2_WHITE_BALANCE_INCANDESCENT         = 2,
+        V4L2_WHITE_BALANCE_FLUORESCENT          = 3,
+        V4L2_WHITE_BALANCE_FLUORESCENT_H        = 4,
+        V4L2_WHITE_BALANCE_HORIZON              = 5,
+        V4L2_WHITE_BALANCE_DAYLIGHT             = 6,
+        V4L2_WHITE_BALANCE_FLASH                = 7,
+        V4L2_WHITE_BALANCE_CLOUDY               = 8,
+        V4L2_WHITE_BALANCE_SHADE                = 9,
+};
+
 /* FM Modulator class control IDs */
 #define V4L2_CID_FM_TX_CLASS_BASE               (V4L2_CTRL_CLASS_FM_TX | 0x900)
 #define V4L2_CID_FM_TX_CLASS                    (V4L2_CTRL_CLASS_FM_TX | 1)