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183 lines
6.2 KiB
Diff
183 lines
6.2 KiB
Diff
From 69f1022fc3c155f8cd5cf7dacaf283b1778835f3 Mon Sep 17 00:00:00 2001
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From: Naushir Patuck <naush@raspberrypi.com>
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Date: Fri, 8 May 2020 09:41:17 +0100
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Subject: [PATCH] media: i2c: imx477: Add support for adaptive frame
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control
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Use V4L2_CID_EXPOSURE_AUTO_PRIORITY to control if the driver should
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automatically adjust the sensor frame length based on exposure time,
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allowing variable frame rates and longer exposures.
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Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
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---
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drivers/media/i2c/imx477.c | 113 +++++++++++++++++++++++++++++--------
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1 file changed, 91 insertions(+), 22 deletions(-)
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--- a/drivers/media/i2c/imx477.c
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+++ b/drivers/media/i2c/imx477.c
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@@ -1082,6 +1082,8 @@ struct imx477 {
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struct v4l2_ctrl *hflip;
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struct v4l2_ctrl *vblank;
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struct v4l2_ctrl *hblank;
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+ /* This ctrl allows automatic variable framerate */
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+ struct v4l2_ctrl *exposure_auto;
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/* Current mode */
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const struct imx477_mode *mode;
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@@ -1278,6 +1280,72 @@ static int imx477_open(struct v4l2_subde
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return 0;
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}
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+static int imx477_set_exposure(struct imx477 *imx477, unsigned int val)
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+{
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+ int ret;
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+
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+ ret = imx477_write_reg(imx477, IMX477_REG_EXPOSURE,
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+ IMX477_REG_VALUE_16BIT, val);
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+
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+ /* Setup the frame length in the case of auto framerate mode. */
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+ if (imx477->exposure_auto->val) {
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+ unsigned int frame_length, frame_length_max, frame_length_min;
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+
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+ frame_length_min = imx477->vblank->minimum +
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+ imx477->mode->height;
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+ frame_length_max = imx477->vblank->maximum +
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+ imx477->mode->height;
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+ frame_length = max(frame_length_min,
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+ val + IMX477_EXPOSURE_OFFSET);
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+ frame_length = min(frame_length_max, frame_length);
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+ ret += imx477_write_reg(imx477, IMX477_REG_FRAME_LENGTH,
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+ IMX477_REG_VALUE_16BIT, frame_length);
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+ }
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+
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+ return ret;
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+}
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+
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+static void imx477_adjust_exposure_range(struct imx477 *imx477,
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+ struct v4l2_ctrl *ctrl)
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+{
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+ int exposure_max, exposure_def;
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+
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+ if (ctrl->id == V4L2_CID_VBLANK || !ctrl->val) {
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+ /*
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+ * Either VBLANK has been changed or auto framerate
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+ * adjusting has been disabled. Honour the VBLANK limits
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+ * when setting exposure.
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+ */
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+ exposure_max = imx477->mode->height + imx477->vblank->val -
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+ IMX477_EXPOSURE_OFFSET;
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+
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+ if (ctrl->id == V4L2_CID_EXPOSURE_AUTO_PRIORITY) {
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+ /*
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+ * Allow VBLANK adjustments since the driver is not
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+ * handling frame length control automatically.
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+ */
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+ __v4l2_ctrl_grab(imx477->vblank, false);
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+ }
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+ } else {
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+ /*
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+ * Auto framerate adjusting has been enabled. VBLANK
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+ * ctrl has been disabled and exposure can ramp up
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+ * to the maximum allowable value.
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+ */
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+ exposure_max = IMX477_EXPOSURE_MAX;
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+ /*
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+ * Do not allow VBLANK adjustments if the driver is
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+ * handling it frame length control automatically.
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+ */
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+ __v4l2_ctrl_grab(imx477->vblank, true);
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+ }
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+
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+ exposure_def = min(exposure_max, imx477->exposure->val);
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+ __v4l2_ctrl_modify_range(imx477->exposure, imx477->exposure->minimum,
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+ exposure_max, imx477->exposure->step,
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+ exposure_def);
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+}
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+
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static int imx477_set_ctrl(struct v4l2_ctrl *ctrl)
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{
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struct imx477 *imx477 =
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@@ -1285,17 +1353,13 @@ static int imx477_set_ctrl(struct v4l2_c
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struct i2c_client *client = v4l2_get_subdevdata(&imx477->sd);
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int ret = 0;
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- if (ctrl->id == V4L2_CID_VBLANK) {
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- int exposure_max, exposure_def;
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-
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- /* Update max exposure while meeting expected vblanking */
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- exposure_max = imx477->mode->height + ctrl->val -
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- IMX477_EXPOSURE_OFFSET;
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- exposure_def = min(exposure_max, imx477->exposure->val);
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- __v4l2_ctrl_modify_range(imx477->exposure,
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- imx477->exposure->minimum,
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- exposure_max, imx477->exposure->step,
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- exposure_def);
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+ if (ctrl->id == V4L2_CID_VBLANK ||
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+ ctrl->id == V4L2_CID_EXPOSURE_AUTO_PRIORITY) {
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+ /*
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+ * These controls may change the limits of usable exposure,
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+ * so check and adjust if necessary.
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+ */
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+ imx477_adjust_exposure_range(imx477, ctrl);
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}
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/*
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@@ -1311,8 +1375,14 @@ static int imx477_set_ctrl(struct v4l2_c
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IMX477_REG_VALUE_16BIT, ctrl->val);
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break;
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case V4L2_CID_EXPOSURE:
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- ret = imx477_write_reg(imx477, IMX477_REG_EXPOSURE,
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- IMX477_REG_VALUE_16BIT, ctrl->val);
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+ ret = imx477_set_exposure(imx477, ctrl->val);
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+ break;
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+ case V4L2_CID_EXPOSURE_AUTO_PRIORITY:
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+ /*
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+ * imx477_set_exposure() will recalculate the frame length
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+ * to adjust the framerate to match the exposure.
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+ */
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+ ret = imx477_set_exposure(imx477, imx477->exposure->val);
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break;
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case V4L2_CID_DIGITAL_GAIN:
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ret = imx477_write_reg(imx477, IMX477_REG_DIGITAL_GAIN,
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@@ -1510,9 +1580,8 @@ unsigned int imx477_get_frame_length(con
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static void imx477_set_framing_limits(struct imx477 *imx477)
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{
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+ unsigned int frm_length_min, frm_length_default, hblank;
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const struct imx477_mode *mode = imx477->mode;
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- unsigned int frm_length_min, frm_length_default;
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- unsigned int exposure_max, exposure_def, hblank;
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frm_length_min = imx477_get_frame_length(mode, &mode->timeperframe_min);
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frm_length_default =
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@@ -1522,15 +1591,10 @@ static void imx477_set_framing_limits(st
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__v4l2_ctrl_modify_range(imx477->vblank, frm_length_min - mode->height,
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IMX477_FRAME_LENGTH_MAX - mode->height,
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1, frm_length_default - mode->height);
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+
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+ /* Setting this will adjust the exposure limits as well. */
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__v4l2_ctrl_s_ctrl(imx477->vblank, frm_length_default - mode->height);
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- /* Update max exposure while meeting expected vblanking */
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- exposure_max = IMX477_FRAME_LENGTH_MAX - IMX477_EXPOSURE_OFFSET;
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- exposure_def = frm_length_default - mode->height -
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- IMX477_EXPOSURE_OFFSET;
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- __v4l2_ctrl_modify_range(imx477->exposure, imx477->exposure->minimum,
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- exposure_max, imx477->exposure->step,
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- exposure_def);
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/*
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* Currently PPL is fixed to the mode specified value, so hblank
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* depends on mode->width only, and is not changeable in any
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@@ -1939,6 +2003,11 @@ static int imx477_init_controls(struct i
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IMX477_DGTL_GAIN_MIN, IMX477_DGTL_GAIN_MAX,
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IMX477_DGTL_GAIN_STEP, IMX477_DGTL_GAIN_DEFAULT);
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+ imx477->exposure_auto =
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+ v4l2_ctrl_new_std(ctrl_hdlr, &imx477_ctrl_ops,
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+ V4L2_CID_EXPOSURE_AUTO_PRIORITY,
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+ 0, 1, 1, 0);
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+
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imx477->hflip = v4l2_ctrl_new_std(ctrl_hdlr, &imx477_ctrl_ops,
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V4L2_CID_HFLIP, 0, 1, 1, 0);
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if (imx477->hflip)
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