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 | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/media/i2c/imx335.c b/drivers/media/i2c/imx335.c index 31d3b95cc0ef..0b06e86583f2 100644 --- a/drivers/media/i2c/imx335.c +++ b/drivers/media/i2c/imx335.c @@ -49,10 +49,10 @@ #define IMX335_REG_AREA3_ST_ADR_1 CCI_REG16_LE(0x3074) #define IMX335_REG_AREA3_WIDTH_1 CCI_REG16_LE(0x3076) -/* Analog gain control */ -#define IMX335_REG_AGAIN CCI_REG8(0x30e8) +/* Analog and Digital gain control */ +#define IMX335_REG_GAIN 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 @@ -479,7 +479,7 @@ static int imx335_update_exp_gain(struct imx335 *imx335, u32 exposure, u32 gain) cci_write(imx335->cci, IMX335_REG_HOLD, 1, &ret); cci_write(imx335->cci, IMX335_REG_VMAX, lpfr, &ret); cci_write(imx335->cci, IMX335_REG_SHUTTER, shutter, &ret); - cci_write(imx335->cci, IMX335_REG_AGAIN, gain, &ret); + cci_write(imx335->cci, IMX335_REG_GAIN, gain, &ret); /* * Unconditionally attempt to release the hold, but track the * error if the unhold itself fails. @@ -1183,6 +1183,14 @@ 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