From 321814f1f361336278e9d682492152098b0a0f00 Mon Sep 17 00:00:00 2001 From: Naushir Patuck Date: Thu, 5 Jan 2023 14:44:48 +0000 Subject: [PATCH] drivers: media: imx708: Enable long exposure mode Enable long exposure modes by using the long exposure shift register setting in the imx708 sensor. Signed-off-by: Naushir Patuck --- drivers/media/i2c/imx708.c | 41 +++++++++++++++++++++++++++++++++----- 1 file changed, 36 insertions(+), 5 deletions(-) --- a/drivers/media/i2c/imx708.c +++ b/drivers/media/i2c/imx708.c @@ -44,6 +44,10 @@ #define IMX708_REG_FRAME_LENGTH 0x0340 #define IMX708_FRAME_LENGTH_MAX 0xffff +/* Long exposure multiplier */ +#define IMX708_LONG_EXP_SHIFT_MAX 7 +#define IMX708_LONG_EXP_SHIFT_REG 0x3100 + /* Exposure control */ #define IMX708_REG_EXPOSURE 0x0202 #define IMX708_EXPOSURE_OFFSET 48 @@ -806,6 +810,9 @@ struct imx708 { /* Rewrite common registers on stream on? */ bool common_regs_written; + + /* Current long exposure factor in use. Set through V4L2_CID_VBLANK */ + unsigned int long_exp_shift; }; static inline struct imx708 *to_imx708(struct v4l2_subdev *_sd) @@ -994,7 +1001,8 @@ static int imx708_set_exposure(struct im * will automatically divide the medium and short ones by 4,16. */ ret = imx708_write_reg(imx708, IMX708_REG_EXPOSURE, - IMX708_REG_VALUE_16BIT, val); + IMX708_REG_VALUE_16BIT, + val >> imx708->long_exp_shift); return ret; } @@ -1027,18 +1035,42 @@ static int imx708_set_analogue_gain(stru return ret; } +static int imx708_set_frame_length(struct imx708 *imx708, unsigned int val) +{ + int ret = 0; + + imx708->long_exp_shift = 0; + + while (val > IMX708_FRAME_LENGTH_MAX) { + imx708->long_exp_shift++; + val >>= 1; + } + + ret = imx708_write_reg(imx708, IMX708_REG_FRAME_LENGTH, + IMX708_REG_VALUE_16BIT, val); + if (ret) + return ret; + + return imx708_write_reg(imx708, IMX708_LONG_EXP_SHIFT_REG, + IMX708_REG_VALUE_08BIT, imx708->long_exp_shift); +} + static void imx708_set_framing_limits(struct imx708 *imx708) { unsigned int hblank; const struct imx708_mode *mode = imx708->mode; + /* Default to no long exposure multiplier */ + imx708->long_exp_shift = 0; + __v4l2_ctrl_modify_range(imx708->pixel_rate, mode->pixel_rate, mode->pixel_rate, 1, mode->pixel_rate); /* Update limits and set FPS to default */ __v4l2_ctrl_modify_range(imx708->vblank, mode->vblank_min, - IMX708_FRAME_LENGTH_MAX - mode->height, + ((1 << IMX708_LONG_EXP_SHIFT_MAX) * + IMX708_FRAME_LENGTH_MAX) - mode->height, 1, mode->vblank_default); /* @@ -1112,9 +1144,8 @@ static int imx708_set_ctrl(struct v4l2_c imx708->vflip->val << 1); break; case V4L2_CID_VBLANK: - ret = imx708_write_reg(imx708, IMX708_REG_FRAME_LENGTH, - IMX708_REG_VALUE_16BIT, - imx708->mode->height + ctrl->val); + ret = imx708_set_frame_length(imx708, + imx708->mode->height + ctrl->val); break; case V4L2_CID_NOTIFY_GAINS: ret = imx708_write_reg(imx708, IMX708_REG_COLOUR_BALANCE_BLUE,