From: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> V4L2 sensor drivers are expected to clip the supported exposure range based on the VBLANK configured. IMX258 wasn't doing that as register 0x350 (FRM_LENGTH_CTL) switches it to a mode where frame length tracks coarse exposure time. Disable this mode and clip the range for V4L2_CID_EXPOSURE appropriately based on V4L2_CID_VBLANK. Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> Reviewed-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx> Signed-off-by: Luis Garcia <git@xxxxxxxxxxxx> --- drivers/media/i2c/imx258.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c index 8f792f0e0738..ebc404b548b3 100644 --- a/drivers/media/i2c/imx258.c +++ b/drivers/media/i2c/imx258.c @@ -37,10 +37,11 @@ /* Exposure control */ #define IMX258_REG_EXPOSURE 0x0202 +#define IMX258_EXPOSURE_OFFSET 10 #define IMX258_EXPOSURE_MIN 4 #define IMX258_EXPOSURE_STEP 1 #define IMX258_EXPOSURE_DEFAULT 0x640 -#define IMX258_EXPOSURE_MAX 65535 +#define IMX258_EXPOSURE_MAX (IMX258_VTS_MAX - IMX258_EXPOSURE_OFFSET) /* Analog gain control */ #define IMX258_REG_ANALOG_GAIN 0x0204 @@ -371,7 +372,7 @@ static const struct imx258_reg mode_common_regs[] = { { 0x303A, 0x00 }, { 0x303B, 0x10 }, { 0x300D, 0x00 }, - { 0x0350, 0x01 }, + { 0x0350, 0x00 }, { 0x0204, 0x00 }, { 0x0205, 0x00 }, { 0x020E, 0x01 }, @@ -734,6 +735,19 @@ static int imx258_update_digital_gain(struct imx258 *imx258, u32 len, u32 val) return 0; } +static void imx258_adjust_exposure_range(struct imx258 *imx258) +{ + int exposure_max, exposure_def; + + /* Honour the VBLANK limits when setting exposure. */ + exposure_max = imx258->cur_mode->height + imx258->vblank->val - + IMX258_EXPOSURE_OFFSET; + exposure_def = min(exposure_max, imx258->exposure->val); + __v4l2_ctrl_modify_range(imx258->exposure, imx258->exposure->minimum, + exposure_max, imx258->exposure->step, + exposure_def); +} + static int imx258_set_ctrl(struct v4l2_ctrl *ctrl) { struct imx258 *imx258 = @@ -741,6 +755,13 @@ static int imx258_set_ctrl(struct v4l2_ctrl *ctrl) struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); int ret = 0; + /* + * The VBLANK control may change the limits of usable exposure, so check + * and adjust if necessary. + */ + if (ctrl->id == V4L2_CID_VBLANK) + imx258_adjust_exposure_range(imx258); + /* * Applying V4L2 control value only happens * when power is up for streaming -- 2.44.0