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8299d1f057
Rebased RPi foundation patches on linux 5.10.59, removed applied and reverted patches, wireless patches and defconfig patches. bcm2708: boot tested on RPi B+ v1.2 bcm2709: boot tested on RPi 4B v1.1 4G bcm2711: boot tested on RPi 4B v1.1 4G Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
127 lines
4.2 KiB
Diff
127 lines
4.2 KiB
Diff
From 973d774838b036ceef91e09a7994558c793b4d8a Mon Sep 17 00:00:00 2001
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From: Naushir Patuck <naush@raspberrypi.com>
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Date: Wed, 10 Feb 2021 10:50:32 +0000
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Subject: [PATCH] media: i2c: imx477: Add very long exposure control to
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the driver
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Add support for very long exposures by using the exposure multiplier
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register. Userland does not need to pass any additional controls to
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enable long exposures, it simply requests a larger vblank to extend the
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exposure control range appropriately.
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Currently, since hblank is fixed, a maximum of approximately 124 seconds
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of exposure time can be used. In a future change, hblank could also be
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controlled in userland to give over 200 seconds of exposure time.
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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 | 47 +++++++++++++++++++++++++++++++++-----
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1 file changed, 41 insertions(+), 6 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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@@ -44,6 +44,10 @@
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#define IMX477_REG_FRAME_LENGTH 0x0340
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#define IMX477_FRAME_LENGTH_MAX 0xffdc
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+/* Long exposure multiplier */
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+#define IMX477_LONG_EXP_SHIFT_MAX 7
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+#define IMX477_LONG_EXP_SHIFT_REG 0x3100
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+
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/* Exposure control */
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#define IMX477_REG_EXPOSURE 0x0202
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#define IMX477_EXPOSURE_OFFSET 22
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@@ -1097,6 +1101,9 @@ struct imx477 {
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/* Rewrite common registers on stream on? */
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bool common_regs_written;
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+
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+ /* Current long exposure factor in use. Set through V4L2_CID_VBLANK */
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+ unsigned int long_exp_shift;
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};
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static inline struct imx477 *to_imx477(struct v4l2_subdev *_sd)
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@@ -1285,13 +1292,33 @@ static void imx477_adjust_exposure_range
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/* Honour the VBLANK limits when setting exposure. */
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exposure_max = imx477->mode->height + imx477->vblank->val -
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- IMX477_EXPOSURE_OFFSET;
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+ (IMX477_EXPOSURE_OFFSET << imx477->long_exp_shift);
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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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+static int imx477_set_frame_length(struct imx477 *imx477, unsigned int val)
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+{
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+ int ret = 0;
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+
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+ imx477->long_exp_shift = 0;
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+
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+ while (val > IMX477_FRAME_LENGTH_MAX) {
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+ imx477->long_exp_shift++;
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+ val >>= 1;
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+ }
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+
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+ ret = imx477_write_reg(imx477, IMX477_REG_FRAME_LENGTH,
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+ IMX477_REG_VALUE_16BIT, val);
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+ if (ret)
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+ return ret;
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+
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+ return imx477_write_reg(imx477, IMX477_LONG_EXP_SHIFT_REG,
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+ IMX477_REG_VALUE_08BIT, imx477->long_exp_shift);
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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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@@ -1299,6 +1326,10 @@ 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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+ /*
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+ * The VBLANK control may change the limits of usable exposure, so check
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+ * and adjust if necessary.
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+ */
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if (ctrl->id == V4L2_CID_VBLANK)
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imx477_adjust_exposure_range(imx477, ctrl);
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@@ -1316,7 +1347,8 @@ static int imx477_set_ctrl(struct v4l2_c
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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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+ IMX477_REG_VALUE_16BIT, ctrl->val >>
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+ imx477->long_exp_shift);
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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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@@ -1350,9 +1382,8 @@ static int imx477_set_ctrl(struct v4l2_c
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imx477->vflip->val << 1);
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break;
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case V4L2_CID_VBLANK:
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- ret = imx477_write_reg(imx477, IMX477_REG_FRAME_LENGTH,
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- IMX477_REG_VALUE_16BIT,
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- imx477->mode->height + ctrl->val);
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+ ret = imx477_set_frame_length(imx477,
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+ imx477->mode->height + ctrl->val);
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break;
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default:
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dev_info(&client->dev,
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@@ -1521,9 +1552,13 @@ static void imx477_set_framing_limits(st
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frm_length_default =
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imx477_get_frame_length(mode, &mode->timeperframe_default);
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+ /* Default to no long exposure multiplier. */
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+ imx477->long_exp_shift = 0;
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+
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/* Update limits and set FPS to default */
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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 << IMX477_LONG_EXP_SHIFT_MAX) *
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+ IMX477_FRAME_LENGTH_MAX) - mode->height,
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1, frm_length_default - mode->height);
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/* Setting this will adjust the exposure limits as well. */
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