target/linux/bcm27xx/patches-5.15/950-0347-media-i2c-imx290-Handle-exposure-correctly-when-vbla.patch

   1 From 312748a4a15eba1d63a0861acabb7941c36e69d7 Mon Sep 17 00:00:00 2001
   2 From: David Plowman <david.plowman@raspberrypi.com>
   3 Date: Thu, 18 Feb 2021 11:58:29 +0000
   4 Subject: [PATCH] media: i2c: imx290: Handle exposure correctly when
   5  vblank changes
   6
   7 When vblank changes we must modify the exposure range. Also, with this
   8 sensor, the effective exposure time implicitly changes when vblank
   9 does, so we have to reset it after every vblank update.
  10
  11 Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
  12 ---
  13  drivers/media/i2c/imx290.c | 18 ++++++++++++++++++
  14  1 file changed, 18 insertions(+)
  15
  16 --- a/drivers/media/i2c/imx290.c
  17 +++ b/drivers/media/i2c/imx290.c
  18 @@ -618,6 +618,24 @@ static int imx290_set_vmax(struct imx290
  19         if (ret)
  20                 dev_err(imx290->dev, "Unable to write vmax\n");
  21
  22 +       /*
  23 +        * Changing vblank changes the allowed range for exposure.
  24 +        * We don't supply the current exposure as default here as it
  25 +        * may lie outside the new range. We will reset it just below.
  26 +        */
  27 +       __v4l2_ctrl_modify_range(imx290->exposure,
  28 +                                IMX290_EXPOSURE_MIN,
  29 +                                vmax - 2,
  30 +                                IMX290_EXPOSURE_STEP,
  31 +                                vmax - 2);
  32 +
  33 +       /*
  34 +        * Becuse of the way exposure works for this sensor, updating
  35 +        * vblank causes the effective exposure to change, so we must
  36 +        * set it back to the "new" correct value.
  37 +        */
  38 +       imx290_set_exposure(imx290, imx290->exposure->val);
  39 +
  40         return ret;
  41  }
  42