There are problems when you use this camera/sensor in a very bright room or
outside. The image is completely white, because it is overexposed. The driver
uses a default value which is not suitable for all environments.
This patch makes it possible to adjust the exposure time by youself. I found
out by logging the i2c-data, that the windows driver for this sensor is doing
this, too.
I tested the camera on a sunny day and after adjusting the exposure time, I was
able to see a very good image.
Signed-off-by: Johannes Obermaier <johannes.oberma...@gmail.com>
---
drivers/media/video/mt9v011.c | 22 +++++++++++++++++++++-
1 files changed, 21 insertions(+), 1 deletions(-)
diff --git a/drivers/media/video/mt9v011.c b/drivers/media/video/mt9v011.c
index a6cf05a..fbbd018 100644
--- a/drivers/media/video/mt9v011.c
+++ b/drivers/media/video/mt9v011.c
@@ -59,6 +59,15 @@ static struct v4l2_queryctrl mt9v011_qctrl[] = {
.default_value = 0x0020,
.flags = 0,
}, {
+ .id = V4L2_CID_EXPOSURE,
+ .type = V4L2_CTRL_TYPE_INTEGER,
+ .name = "Exposure",
+ .minimum = 0,
+ .maximum = 2047,
+ .step = 1,
+ .default_value = 0x01fc,
+ .flags = 0,
+ }, {
.id = V4L2_CID_RED_BALANCE,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "Red Balance",
@@ -105,7 +114,7 @@ struct mt9v011 {
unsigned hflip:1;
unsigned vflip:1;
- u16 global_gain, red_bal, blue_bal;
+ u16 global_gain, exposure, red_bal, blue_bal;
};
static inline struct mt9v011 *to_mt9v011(struct v4l2_subdev *sd)
@@ -184,6 +193,9 @@ static void set_balance(struct v4l2_subdev *sd)
{
struct mt9v011 *core = to_mt9v011(sd);
u16 green1_gain, green2_gain, blue_gain, red_gain;
+ u16 exposure;
+
+ exposure = core->exposure;
green1_gain = core->global_gain;
green2_gain = core->global_gain;
@@ -198,6 +210,7 @@ static void set_balance(struct v4l2_subdev *sd)
mt9v011_write(sd, R2E_MT9V011_GREEN_2_GAIN, green1_gain);
mt9v011_write(sd, R2C_MT9V011_BLUE_GAIN, blue_gain);
mt9v011_write(sd, R2D_MT9V011_RED_GAIN, red_gain);
+ mt9v011_write(sd, R09_MT9V011_SHUTTER_WIDTH, exposure);
}
static void calc_fps(struct v4l2_subdev *sd, u32 *numerator, u32 *denominator)
@@ -338,6 +351,9 @@ static int mt9v011_g_ctrl(struct v4l2_subdev *sd, struct
v4l2_control *ctrl)
case V4L2_CID_GAIN:
ctrl->value = core->global_gain;
return 0;
+ case V4L2_CID_EXPOSURE:
+ ctrl->value = core->exposure;
+ return 0;
case V4L2_CID_RED_BALANCE:
ctrl->value = core->red_bal;
return 0;
@@ -392,6 +408,9 @@ static int mt9v011_s_ctrl(struct v4l2_subdev *sd, struct
v4l2_control *ctrl)
case V4L2_CID_GAIN:
core->global_gain = ctrl->value;
break;
+ case V4L2_CID_EXPOSURE:
+ core->exposure = ctrl->value;
+ break;
case V4L2_CID_RED_BALANCE:
core->red_bal = ctrl->value;
break;
@@ -598,6 +617,7 @@ static int mt9v011_probe(struct i2c_client *c,
}
core->global_gain = 0x0024;
+ core->exposure = 0x01fc;
core->width = 640;
core->height = 480;
core->xtal = 27000000; /* Hz */
--
1.6.4.2
--
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