The sensor gain (both analog and digital) are controlled by a single gain value where: - 0dB to 30dB correspond to analog gain - 30.3dB to 72dB correspond to digital gain (with 0.3dB step) Hence, limit the analogue gain value to 100. For digital gain, support can be added later if needed. Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx> Reviewed-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx> Reviewed-by: Tommaso Merciai <tomm.merciai@xxxxxxxxx> --- drivers/media/i2c/imx335.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/media/i2c/imx335.c b/drivers/media/i2c/imx335.c index 75f4b4e0a5da..4bd547ca71c8 100644 --- a/drivers/media/i2c/imx335.c +++ b/drivers/media/i2c/imx335.c @@ -52,7 +52,7 @@ /* Analog gain control */ #define IMX335_REG_AGAIN CCI_REG8(0x30e8) #define IMX335_AGAIN_MIN 0 -#define IMX335_AGAIN_MAX 240 +#define IMX335_AGAIN_MAX 100 #define IMX335_AGAIN_STEP 1 #define IMX335_AGAIN_DEFAULT 0 @@ -1175,6 +1175,14 @@ static int imx335_init_controls(struct imx335 *imx335) IMX335_EXPOSURE_STEP, IMX335_EXPOSURE_DEFAULT); + /* + * The sensor has an analog gain and a digital gain, both controlled + * through a single gain value, expressed in 0.3dB increments. Values + * from 0.0dB (0) to 30.0dB (100) apply analog gain only, higher values + * up to 72.0dB (240) add further digital gain. Limit the range to + * analog gain only, support for digital gain can be added separately + * if needed. + */ imx335->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr, &imx335_ctrl_ops, V4L2_CID_ANALOGUE_GAIN, -- 2.43.0
