V4L/DVB (12512): ov772x: implement a band-stop filter support

The V4L2_CID_BAND_STOP_FILTER control is used to switch the "Banding Filter" on
OV772x cameras on and off and to set the minimum AEC value in BDBASE register.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 50 insertions, 2 deletions

diff --git a/drivers/media/video/ov772x.c b/drivers/media/video/ov772x.c
index 119159773a68..4c550f91ca24 100644
--- a/drivers/media/video/ov772x.c
+++ b/drivers/media/video/ov772x.c
@@ -403,8 +403,9 @@ struct ov772x_priv {
         const struct ov772x_color_format *fmt;
         const struct ov772x_win_size     *win;
         int                               model;
-        unsigned int                      flag_vflip:1;
-        unsigned int                      flag_hflip:1;
+        unsigned short                    flag_vflip:1;
+        unsigned short                    flag_hflip:1;
+        unsigned short                    band_filter;  /* 256 - BDBASE, 0 if (!COM8[5]) */
 };
 
 #define ENDMARKER { 0xff, 0xff }
@@ -569,6 +570,15 @@ static const struct v4l2_queryctrl ov772x_controls[] = {
                 .step           = 1,
                 .default_value  = 0,
         },
+        {
+                .id             = V4L2_CID_BAND_STOP_FILTER,
+                .type           = V4L2_CTRL_TYPE_INTEGER,
+                .name           = "Band-stop filter",
+                .minimum        = 0,
+                .maximum        = 256,
+                .step           = 1,
+                .default_value  = 0,
+        },
 };
 
 
@@ -674,6 +684,9 @@ static int ov772x_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
         case V4L2_CID_HFLIP:
                 ctrl->value = priv->flag_hflip;
                 break;
+        case V4L2_CID_BAND_STOP_FILTER:
+                ctrl->value = priv->band_filter;
+                break;
         }
         return 0;
 }
@@ -700,6 +713,29 @@ static int ov772x_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
                         val ^= HFLIP_IMG;
                 ret = ov772x_mask_set(client, COM3, HFLIP_IMG, val);
                 break;
+        case V4L2_CID_BAND_STOP_FILTER:
+                if ((unsigned)ctrl->value > 256)
+                        ctrl->value = 256;
+                if (ctrl->value == priv->band_filter)
+                        break;
+                if (!ctrl->value) {
+                        /* Switch the filter off, it is on now */
+                        ret = ov772x_mask_set(client, BDBASE, 0xff, 0xff);
+                        if (!ret)
+                                ret = ov772x_mask_set(client, COM8,
+                                                      BNDF_ON_OFF, 0);
+                } else {
+                        /* Switch the filter on, set AEC low limit */
+                        val = 256 - ctrl->value;
+                        ret = ov772x_mask_set(client, COM8,
+                                              BNDF_ON_OFF, BNDF_ON_OFF);
+                        if (!ret)
+                                ret = ov772x_mask_set(client, BDBASE,
+                                                      0xff, val);
+                }
+                if (!ret)
+                        priv->band_filter = ctrl->value;
+                break;
         }
 
         return ret;
@@ -893,6 +929,18 @@ static int ov772x_set_params(struct i2c_client *client,
         if (ret < 0)
                 goto ov772x_set_fmt_error;
 
+        /*
+         * set COM8
+         */
+        if (priv->band_filter) {
+                ret = ov772x_mask_set(client, COM8, BNDF_ON_OFF, 1);
+                if (!ret)
+                        ret = ov772x_mask_set(client, BDBASE,
+                                              0xff, 256 - priv->band_filter);
+                if (ret < 0)
+                        goto ov772x_set_fmt_error;
+        }
+
         return ret;
 
 ov772x_set_fmt_error: