[PATCH v5 01/16] media: ov8858: Extract digital gain programming

[Maurizio Casciano <mauriziocasciano7@gmail.com>]

Move the existing packed digital-gain register programming into a
helper so clock-specific gain handling can be added separately.

This is a pure refactoring: preserve both the register packing and the
explanatory comment without changing the bytes written to the sensor.

Assisted-by: LLM sparse
Signed-off-by: Maurizio Casciano <mauriziocasciano7@gmail.com>
---
 drivers/media/i2c/ov8858.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/media/i2c/ov8858.c b/drivers/media/i2c/ov8858.c
index 3f45f7fab833..d95f034de752 100644
--- a/drivers/media/i2c/ov8858.c
+++ b/drivers/media/i2c/ov8858.c
@@ -1523,6 +1523,23 @@ static int ov8858_enable_test_pattern(struct ov8858 *ov8858, u32 pattern)
 	return ov8858_write(ov8858, OV8858_REG_TEST_PATTERN, val, NULL);
 }
 
+static int ov8858_set_long_digital_gain(struct ov8858 *ov8858, u32 gain)
+{
+	u16 long_gain;
+
+	/*
+	 * Digital gain is assembled as:
+	 * 0x350a[7:0] = dgain[13:6]
+	 * 0x350b[5:0] = dgain[5:0]
+	 * Reassemble the control value to write it in one go.
+	 */
+	long_gain = (gain & OV8858_LONG_DIGIGAIN_L_MASK) |
+		    ((gain & OV8858_LONG_DIGIGAIN_H_MASK) <<
+		     OV8858_LONG_DIGIGAIN_H_SHIFT);
+
+	return ov8858_write(ov8858, OV8858_REG_LONG_DIGIGAIN, long_gain, NULL);
+}
+
 static int ov8858_set_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct ov8858 *ov8858 = container_of(ctrl->handler,
@@ -1531,7 +1548,6 @@ static int ov8858_set_ctrl(struct v4l2_ctrl *ctrl)
 	struct i2c_client *client = v4l2_get_subdevdata(&ov8858->subdev);
 	struct v4l2_mbus_framefmt *format;
 	struct v4l2_subdev_state *state;
-	u16 digi_gain;
 	s64 max_exp;
 	int ret;
 
@@ -1570,17 +1586,7 @@ static int ov8858_set_ctrl(struct v4l2_ctrl *ctrl)
 				   ctrl->val, NULL);
 		break;
 	case V4L2_CID_DIGITAL_GAIN:
-		/*
-		 * Digital gain is assembled as:
-		 * 0x350a[7:0] = dgain[13:6]
-		 * 0x350b[5:0] = dgain[5:0]
-		 * Reassemble the control value to write it in one go.
-		 */
-		digi_gain = (ctrl->val & OV8858_LONG_DIGIGAIN_L_MASK)
-			  | ((ctrl->val & OV8858_LONG_DIGIGAIN_H_MASK) <<
-			      OV8858_LONG_DIGIGAIN_H_SHIFT);
-		ret = ov8858_write(ov8858, OV8858_REG_LONG_DIGIGAIN,
-				   digi_gain, NULL);
+		ret = ov8858_set_long_digital_gain(ov8858, ctrl->val);
 		break;
 	case V4L2_CID_VBLANK:
 		ret = ov8858_write(ov8858, OV8858_REG_VTS,
-- 
With Best Regards,
Maurizio Casciano