media: i2c: cap exposure at height + vblank in ov8865

Exposure limits depend on the total height; when vblank is altered (and
thus the total height is altered), change the exposure limits to reflect
the new cap.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/i2c/ov8865.c b/drivers/media/i2c/ov8865.c
index f4a899e..811438c 100644 (file)
--- a/drivers/media/i2c/ov8865.c
+++ b/drivers/media/i2c/ov8865.c
@@ -143,6 +143,7 @@
 #define OV8865_EXPOSURE_CTRL_L_REG             0x3502
 #define OV8865_EXPOSURE_CTRL_L(v)              ((v) & GENMASK(7, 0))
 #define OV8865_EXPOSURE_GAIN_MANUAL_REG                0x3503
+#define OV8865_INTEGRATION_TIME_MARGIN         8
 
 #define OV8865_GAIN_CTRL_H_REG                 0x3508
 #define OV8865_GAIN_CTRL_H(v)                  (((v) & GENMASK(12, 8)) >> 8)
@@ -677,6 +678,7 @@ struct ov8865_ctrls {
        struct v4l2_ctrl *pixel_rate;
        struct v4l2_ctrl *hblank;
        struct v4l2_ctrl *vblank;
+       struct v4l2_ctrl *exposure;
 
        struct v4l2_ctrl_handler handler;
 };
@@ -2454,6 +2456,20 @@ static int ov8865_s_ctrl(struct v4l2_ctrl *ctrl)
        unsigned int index;
        int ret;
 
+       /* If VBLANK is altered we need to update exposure to compensate */
+       if (ctrl->id == V4L2_CID_VBLANK) {
+               int exposure_max;
+
+               exposure_max = sensor->state.mode->output_size_y + ctrl->val -
+                              OV8865_INTEGRATION_TIME_MARGIN;
+               __v4l2_ctrl_modify_range(sensor->ctrls.exposure,
+                                        sensor->ctrls.exposure->minimum,
+                                        exposure_max,
+                                        sensor->ctrls.exposure->step,
+                                        min(sensor->ctrls.exposure->val,
+                                            exposure_max));
+       }
+
        /* Wait for the sensor to be on before setting controls. */
        if (pm_runtime_suspended(sensor->dev))
                return 0;
@@ -2510,8 +2526,8 @@ static int ov8865_ctrls_init(struct ov8865_sensor *sensor)
 
        /* Exposure */
 
-       v4l2_ctrl_new_std(handler, ops, V4L2_CID_EXPOSURE, 16, 1048575, 16,
-                         512);
+       ctrls->exposure = v4l2_ctrl_new_std(handler, ops, V4L2_CID_EXPOSURE, 16,
+                                           1048575, 16, 512);
 
        /* Gain */
 
@@ -2700,6 +2716,7 @@ static int ov8865_set_fmt(struct v4l2_subdev *subdev,
        u32 mbus_code = 0;
        unsigned int hblank;
        unsigned int index;
+       int exposure_max;
        int ret = 0;
 
        mutex_lock(&sensor->mutex);
@@ -2747,6 +2764,13 @@ static int ov8865_set_fmt(struct v4l2_subdev *subdev,
        __v4l2_ctrl_modify_range(sensor->ctrls.hblank, hblank, hblank, 1,
                                 hblank);
 
+       exposure_max = mode->vts - OV8865_INTEGRATION_TIME_MARGIN;
+       __v4l2_ctrl_modify_range(sensor->ctrls.exposure,
+                                sensor->ctrls.exposure->minimum, exposure_max,
+                                sensor->ctrls.exposure->step,
+                                min(sensor->ctrls.exposure->val,
+                                    exposure_max));
+
 complete:
        mutex_unlock(&sensor->mutex);