git.openwrt.org Git - openwrt/staging/neocturne.git/blob

   1 From 4721f56a81e13353f6900a7346bebf330d3d560b Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 31 Mar 2022 16:45:36 +0100
   4 Subject: [PATCH] media: i2c: imx258: Add support for long exposure
   5  modes
   6
   7 The sensor has a register CIT_LSHIFT which extends the exposure
   8 and frame times by the specified power of 2 for longer
   9 exposure times.
  10
  11 Add support for this by configuring this register via V4L2_CID_VBLANK
  12 and extending the V4L2_CID_EXPOSURE range accordingly.
  13
  14 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  15 ---
  16  drivers/media/i2c/imx258.c | 38 ++++++++++++++++++++++++++++++++------
  17  1 file changed, 32 insertions(+), 6 deletions(-)
  18
  19 --- a/drivers/media/i2c/imx258.c
  20 +++ b/drivers/media/i2c/imx258.c
  21 @@ -69,6 +69,10 @@
  22  #define IMX258_HDR_RATIO_STEP          1
  23  #define IMX258_HDR_RATIO_DEFAULT       0x0
  24
  25 +/* Long exposure multiplier */
  26 +#define IMX258_LONG_EXP_SHIFT_MAX      7
  27 +#define IMX258_LONG_EXP_SHIFT_REG      0x3002
  28 +
  29  /* Test Pattern Control */
  30  #define IMX258_REG_TEST_PATTERN                0x0600
  31
  32 @@ -843,6 +847,8 @@ struct imx258 {
  33         struct v4l2_ctrl *exposure;
  34         struct v4l2_ctrl *hflip;
  35         struct v4l2_ctrl *vflip;
  36 +       /* Current long exposure factor in use. Set through V4L2_CID_VBLANK */
  37 +       unsigned int long_exp_shift;
  38
  39         /* Current mode */
  40         const struct imx258_mode *cur_mode;
  41 @@ -1020,6 +1026,26 @@ static void imx258_adjust_exposure_range
  42                                  exposure_def);
  43  }
  44
  45 +static int imx258_set_frame_length(struct imx258 *imx258, unsigned int val)
  46 +{
  47 +       int ret;
  48 +
  49 +       imx258->long_exp_shift = 0;
  50 +
  51 +       while (val > IMX258_VTS_MAX) {
  52 +               imx258->long_exp_shift++;
  53 +               val >>= 1;
  54 +       }
  55 +
  56 +       ret = imx258_write_reg(imx258, IMX258_REG_VTS,
  57 +                              IMX258_REG_VALUE_16BIT, val);
  58 +       if (ret)
  59 +               return ret;
  60 +
  61 +       return imx258_write_reg(imx258, IMX258_LONG_EXP_SHIFT_REG,
  62 +                               IMX258_REG_VALUE_08BIT, imx258->long_exp_shift);
  63 +}
  64 +
  65  static int imx258_set_ctrl(struct v4l2_ctrl *ctrl)
  66  {
  67         struct imx258 *imx258 =
  68 @@ -1050,7 +1076,7 @@ static int imx258_set_ctrl(struct v4l2_c
  69         case V4L2_CID_EXPOSURE:
  70                 ret = imx258_write_reg(imx258, IMX258_REG_EXPOSURE,
  71                                 IMX258_REG_VALUE_16BIT,
  72 -                               ctrl->val);
  73 +                               ctrl->val >> imx258->long_exp_shift);
  74                 break;
  75         case V4L2_CID_DIGITAL_GAIN:
  76                 ret = imx258_update_digital_gain(imx258, IMX258_REG_VALUE_16BIT,
  77 @@ -1078,9 +1104,8 @@ static int imx258_set_ctrl(struct v4l2_c
  78                 }
  79                 break;
  80         case V4L2_CID_VBLANK:
  81 -               ret = imx258_write_reg(imx258, IMX258_REG_VTS,
  82 -                                      IMX258_REG_VALUE_16BIT,
  83 -                                      imx258->cur_mode->height + ctrl->val);
  84 +               ret = imx258_set_frame_length(imx258,
  85 +                                             imx258->cur_mode->height + ctrl->val);
  86                 break;
  87         case V4L2_CID_VFLIP:
  88         case V4L2_CID_HFLIP:
  89 @@ -1218,8 +1243,9 @@ static int imx258_set_pad_format(struct
  90                              imx258->cur_mode->height;
  91                 __v4l2_ctrl_modify_range(
  92                         imx258->vblank, vblank_min,
  93 -                       IMX258_VTS_MAX - imx258->cur_mode->height, 1,
  94 -                       vblank_def);
  95 +                       ((1 << IMX258_LONG_EXP_SHIFT_MAX) * IMX258_VTS_MAX) -
  96 +                                               imx258->cur_mode->height,
  97 +                       1, vblank_def);
  98                 __v4l2_ctrl_s_ctrl(imx258->vblank, vblank_def);
  99                 h_blank =
 100                         imx258->link_freq_configs[mode->link_freq_index].pixels_per_line