[PATCH v3 2/3] media: i2c: Add Sony IMX681 sensor driver
From: Sergey Lebedev
Date: Wed Sep 09 2026 - 17:09:40 EST
From: Andre Gilerson <andre.gilerson@xxxxxxxxx>
The Sony IMX681 is the user-facing camera on the Microsoft Surface Pro 11
for Business (Intel Lunar Lake, IPU7), where it is enumerated as ACPI
device SONY0681. Without a driver the camera does not appear at all.
There is no public documentation for this sensor. The initialisation
sequence and the mode registers were recovered from I2C traces taken under
Windows, and the driver does not pretend otherwise: imx681_init_regs[] is
21 register writes whose individual meaning is not known.
What is not from the traces is derived and written down. The link frequency
comes from the PLL configuration visible in the same traces - 19.2 MHz
EXCK, PLL2_MUL 303, PLL2_PRE_DIV 3, giving 1939.2 MHz on the bus and
therefore 969.6 MHz per lane - and the pixel rate follows from that, the
lane count and the bit depth. The gain law and the black level were
measured against the sensor rather than taken from the traces; the numbers
are in the cover letter.
The driver uses the streams API, v4l2-cci for register access, the subdev
state API and runtime PM, and validates the endpoint's lane count and link
frequency against what the firmware describes.
Signed-off-by: Andre Gilerson <andre.gilerson@xxxxxxxxx>
Signed-off-by: Sergey Lebedev <lsa.uz@xxxxx>
---
MAINTAINERS | 8 +
drivers/media/i2c/Kconfig | 10 +
drivers/media/i2c/Makefile | 1 +
drivers/media/i2c/imx681.c | 884 +++++++++++++++++++++++++++++++++++++
4 files changed, 903 insertions(+)
create mode 100644 drivers/media/i2c/imx681.c
diff --git a/MAINTAINERS b/MAINTAINERS
index e12dc3ca5..198eaeefa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25586,6 +25586,14 @@ S: Maintained
F: Documentation/devicetree/bindings/media/i2c/sony,imx678.yaml
F: drivers/media/i2c/imx678.c
+SONY IMX681 SENSOR DRIVER
+M: Andre Gilerson <andre.gilerson@xxxxxxxxx>
+L: linux-media@xxxxxxxxxxxxxxx
+S: Maintained
+T: git git://linuxtv.org/media.git
+F: Documentation/devicetree/bindings/media/i2c/sony,imx681.yaml
+F: drivers/media/i2c/imx681.c
+
SONY MEMORYSTICK SUBSYSTEM
M: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
M: Alex Dubov <oakad@xxxxxxxxx>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 5c52007f9..5f7b0d22c 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -310,6 +310,16 @@ config VIDEO_IMX678
To compile this driver as a module, choose M here: the
module will be called imx678.
+config VIDEO_IMX681
+ tristate "Sony IMX681 sensor support"
+ select V4L2_CCI_I2C
+ help
+ This is a Video4Linux2 sensor driver for the Sony
+ IMX681 camera.
+
+ To compile this driver as a module, choose M here: the
+ module will be called imx681.
+
config VIDEO_MAX9271_LIB
tristate
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index d04bd5724..8d6bd7466 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -63,6 +63,7 @@ obj-$(CONFIG_VIDEO_IMX412) += imx412.o
obj-$(CONFIG_VIDEO_IMX415) += imx415.o
obj-$(CONFIG_VIDEO_IMX678) += imx678.o
obj-$(CONFIG_VIDEO_IMX471) += imx471.o
+obj-$(CONFIG_VIDEO_IMX681) += imx681.o
obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
diff --git a/drivers/media/i2c/imx681.c b/drivers/media/i2c/imx681.c
new file mode 100644
index 000000000..eba792ca1
--- /dev/null
+++ b/drivers/media/i2c/imx681.c
@@ -0,0 +1,884 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sony IMX681 CMOS Image Sensor Driver
+ *
+ * Front camera on Surface Pro 11 Business (Intel/Lunar Lake).
+ * Register sequences reverse-engineered from Windows I2C traces.
+ *
+ * Copyright (C) 2025
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+
+#include <media/v4l2-cci.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+
+/* Chip ID register and expected value */
+#define IMX681_REG_CHIP_ID CCI_REG16(0x0016)
+#define IMX681_CHIP_ID 0x0681
+
+/* Mode select */
+#define IMX681_REG_MODE_SELECT CCI_REG8(0x0100)
+#define IMX681_MODE_STANDBY 0x00
+#define IMX681_MODE_STREAMING 0x01
+
+/* Group parameter hold */
+#define IMX681_REG_GROUP_HOLD CCI_REG8(0x0104)
+
+/* Exposure (coarse integration time, 24-bit) */
+#define IMX681_REG_EXPOSURE CCI_REG24(0x0229)
+#define IMX681_EXPOSURE_MIN 4
+#define IMX681_EXPOSURE_MAX 3173 /* frame_length - 4 */
+#define IMX681_EXPOSURE_OFFSET 4 /* frame_length - exposure_max */
+#define IMX681_EXPOSURE_DEFAULT 1907 /* from Windows trace */
+
+/* Analog gain */
+#define IMX681_REG_ANALOG_GAIN CCI_REG16(0x0204)
+#define IMX681_ANA_GAIN_MIN 0
+#define IMX681_ANA_GAIN_MAX 960 /* 16x, where the analogue stage ends */
+#define IMX681_ANA_GAIN_DEFAULT 0
+
+/* Digital gain */
+#define IMX681_REG_DIGITAL_GAIN CCI_REG16(0x020E)
+#define IMX681_DIG_GAIN_MIN 0x0100 /* 1.0x */
+#define IMX681_DIG_GAIN_MAX 0x0FFF
+#define IMX681_DIG_GAIN_DEFAULT 0x0100
+
+/* Test pattern */
+#define IMX681_REG_TEST_PATTERN CCI_REG16(0x0600)
+
+/* Frame length (24-bit, for streaming updates) */
+#define IMX681_REG_FRAME_LENGTH CCI_REG24(0x033D)
+
+/* Image dimensions — native sensor output */
+#define IMX681_WIDTH 3844
+#define IMX681_HEIGHT 2640
+#define IMX681_LINE_LENGTH_PCK 7552 /* 0x1D80 */
+#define IMX681_FRAME_LENGTH_LINES 3177 /* 0x0C69 */
+#define IMX681_FRAME_LENGTH_MAX 0xFFFF /* 24-bit reg, limit to 16-bit */
+
+/* MIPI lanes */
+#define IMX681_NUM_LANES 2
+
+/*
+ * Link frequency derived from PLL settings in Windows trace:
+ * EXCK=19.2MHz, PLL2_MUL=303, PLL2_PRE_DIV=3
+ * OP output = 19.2 * 303 / 3 = 1939.2 MHz (MIPI bit rate)
+ * Link freq = 1939.2 / 2 (DDR) = 969.6 MHz
+ */
+#define IMX681_LINK_FREQ 969600000LL
+
+/* Pixel rate = link_freq * 2 (DDR) * num_lanes / bpp */
+#define IMX681_PIXEL_RATE (IMX681_LINK_FREQ * 2 * IMX681_NUM_LANES / 10)
+
+/* Power-on delay after reset deassert */
+#define IMX681_RESET_DELAY_US 1000
+#define IMX681_RESET_DELAY_RANGE_US 1000
+
+/* Post-standby-cancel stabilisation delays */
+#define IMX681_INIT_DELAY_US 10000
+
+#define IMAGE_PAD 0
+
+static const s64 imx681_link_frequencies[] = {
+ IMX681_LINK_FREQ,
+};
+
+/*
+ * Sensor init register sequence, captured from Windows I2C traces.
+ * This configures the sensor for 3844x2640 RAW10 output at ~30fps
+ * with 2-lane MIPI CSI-2, 19.2MHz input clock.
+ */
+static const struct cci_reg_sequence imx681_init_regs[] = {
+ /* Software standby */
+ { CCI_REG8(0x0100), 0x00 },
+ /* External clock frequency = 19.2 MHz (encoded as MHz * 256) */
+ { CCI_REG16(0x0136), 0x1333 },
+ /* Vendor specific configuration */
+ { CCI_REG16(0x002C), 0x0505 },
+ /* CSI-2 signaling mode */
+ { CCI_REG8(0x0111), 0x02 },
+ /* Image orientation: H-flip to match Windows AIQB (RGGB native → GRBG) */
+ { CCI_REG8(0x0101), 0x01 },
+ /* Vendor access unlock sequence */
+ { CCI_REG8(0x30EB), 0x05 },
+ { CCI_REG8(0x30EB), 0x0C },
+ /* Vendor specific */
+ { CCI_REG16(0x300A), 0xFFFF },
+ { CCI_REG16(0x3532), 0xFFFF },
+ /* LINE_LENGTH_PCK = 7552 */
+ { CCI_REG16(0x0342), 0x1D80 },
+ /* Frame length = 3177 */
+ { CCI_REG16(0x033E), 0x0C69 },
+ /* Crop window start: X_ADD_STA[7:0]=100, Y_ADD_STA=256 */
+ { CCI_REG24(0x0345), 0x640100 },
+ /* Crop window end: X_ADD_END[7:0]=103, Y_ADD_END=2895 */
+ { CCI_REG24(0x0349), 0x670B4F },
+ /* Digital crop / vendor config */
+ { CCI_REG24(0x040D), 0x040A50 },
+ /* X_OUTPUT_SIZE=3844, Y_OUTPUT_SIZE=2640 */
+ { CCI_REG32(0x034C), 0x0F040A50 },
+ /* PLL multiplier = 225 */
+ { CCI_REG8(0x0307), 0xE1 },
+ /* PLL2: pre_div=3, multiplier=303 (0x012F) */
+ { CCI_REG24(0x030D), 0x03012F },
+ /* Frame duration initial */
+ { CCI_REG16(0x022A), 0x0C61 },
+ /* Vendor specific registers */
+ { CCI_REG8(0x7E9B), 0x02 },
+ { CCI_REG8(0x0368), 0x00 },
+ { CCI_REG8(0xD383), 0x01 },
+};
+
+/*
+ * First exposure settings applied before stream-on.
+ * Uses group parameter hold to ensure atomic update.
+ */
+static const struct cci_reg_sequence imx681_first_exposure[] = {
+ { CCI_REG8(0x0104), 0x01 }, /* Group hold ON */
+ { CCI_REG24(0x033D), 0x000C69 }, /* Frame length = 3177 */
+ { CCI_REG24(0x0229), 0x000773 }, /* Exposure = 1907 lines */
+ { CCI_REG16(0x0204), 0x0000 }, /* Analog gain = 0 (1x) */
+ { CCI_REG16(0x020E), 0x0100 }, /* Digital gain = 1.0x */
+ { CCI_REG8(0x0104), 0x00 }, /* Group hold OFF */
+};
+
+static const char * const imx681_test_pattern_menu[] = {
+ "Disabled",
+ "Solid Colour",
+ "Eight Vertical Colour Bars",
+ "Colour Bars With Fade to Grey",
+ "Pseudorandom Sequence (PN9)",
+};
+
+static const u32 imx681_mbus_codes[] = {
+ MEDIA_BUS_FMT_SGRBG10_1X10,
+};
+
+/* Regulator supplies */
+static const char * const imx681_supply_names[] = {
+ "avdd", /* Analog 2.8V */
+ "dvdd", /* Digital 1.05V */
+ "dovdd", /* I/O 1.8V */
+};
+
+#define IMX681_NUM_SUPPLIES ARRAY_SIZE(imx681_supply_names)
+
+struct imx681 {
+ struct device *dev;
+ struct regmap *cci;
+
+ struct v4l2_subdev sd;
+ struct media_pad pad;
+
+ struct clk *xclk;
+ struct gpio_desc *reset_gpio;
+ struct regulator_bulk_data supplies[IMX681_NUM_SUPPLIES];
+
+ /* V4L2 Controls */
+ struct v4l2_ctrl_handler ctrl_handler;
+ struct v4l2_ctrl *exposure;
+ struct v4l2_ctrl *vblank;
+ struct v4l2_ctrl *hblank;
+
+ unsigned long link_freq_bitmap;
+};
+
+static inline struct imx681 *to_imx681(struct v4l2_subdev *sd)
+{
+ return container_of_const(sd, struct imx681, sd);
+}
+
+static int imx681_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+ struct imx681 *imx681 = container_of(ctrl->handler, struct imx681,
+ ctrl_handler);
+ s64 exposure_max;
+ int pm_status;
+ int ret = 0;
+
+ /* Update exposure max when VBLANK changes (even when not streaming) */
+ if (ctrl->id == V4L2_CID_VBLANK) {
+ exposure_max = IMX681_HEIGHT + ctrl->val - IMX681_EXPOSURE_OFFSET;
+ __v4l2_ctrl_modify_range(imx681->exposure,
+ IMX681_EXPOSURE_MIN, exposure_max,
+ 1, IMX681_EXPOSURE_DEFAULT);
+ }
+
+ /*
+ * 1 with a reference taken, 0 if the device is not active, or -EINVAL
+ * if runtime PM is unavailable. Only the 0 means there is nothing to
+ * do: without runtime PM the sensor is powered from probe and never
+ * suspended, so the write still has to go out - but no reference was
+ * taken then, and none may be dropped.
+ */
+ pm_status = pm_runtime_get_if_active(imx681->dev);
+ if (!pm_status)
+ return 0;
+
+ switch (ctrl->id) {
+ case V4L2_CID_VBLANK:
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x01, &ret);
+ cci_write(imx681->cci, IMX681_REG_FRAME_LENGTH,
+ IMX681_HEIGHT + ctrl->val, &ret);
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x00, &ret);
+ dev_dbg(imx681->dev, "set frame_length: %d, ret=%d\n",
+ IMX681_HEIGHT + ctrl->val, ret);
+ break;
+
+ case V4L2_CID_EXPOSURE:
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x01, &ret);
+ cci_write(imx681->cci, IMX681_REG_EXPOSURE, ctrl->val, &ret);
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x00, &ret);
+ dev_dbg(imx681->dev, "set exposure: %d, ret=%d\n",
+ ctrl->val, ret);
+ break;
+
+ case V4L2_CID_ANALOGUE_GAIN:
+ /* Gain formula: gain = 1024/(1024-code); code 960 is 16x. */
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x01, &ret);
+ cci_write(imx681->cci, IMX681_REG_ANALOG_GAIN, ctrl->val,
+ &ret);
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x00, &ret);
+ dev_dbg(imx681->dev, "set analogue gain code %d, ret=%d\n",
+ ctrl->val, ret);
+ break;
+
+ case V4L2_CID_DIGITAL_GAIN:
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x01, &ret);
+ cci_write(imx681->cci, IMX681_REG_DIGITAL_GAIN, ctrl->val,
+ &ret);
+ cci_write(imx681->cci, IMX681_REG_GROUP_HOLD, 0x00, &ret);
+ dev_dbg(imx681->dev, "set digital gain: %d, ret=%d\n",
+ ctrl->val, ret);
+ break;
+
+ case V4L2_CID_TEST_PATTERN:
+ ret = cci_write(imx681->cci, IMX681_REG_TEST_PATTERN,
+ ctrl->val, NULL);
+ break;
+
+ default:
+ dev_dbg(imx681->dev, "unhandled ctrl id: 0x%x val: 0x%x\n",
+ ctrl->id, ctrl->val);
+ break;
+ }
+
+ if (pm_status > 0)
+ pm_runtime_put(imx681->dev);
+ return ret;
+}
+
+static const struct v4l2_ctrl_ops imx681_ctrl_ops = {
+ .s_ctrl = imx681_set_ctrl,
+};
+
+static int imx681_enum_mbus_code(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state,
+ struct v4l2_subdev_mbus_code_enum *code)
+{
+ if (code->index >= ARRAY_SIZE(imx681_mbus_codes))
+ return -EINVAL;
+
+ code->code = imx681_mbus_codes[code->index];
+ return 0;
+}
+
+static bool imx681_is_valid_mbus_code(u32 code)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(imx681_mbus_codes); i++)
+ if (imx681_mbus_codes[i] == code)
+ return true;
+ return false;
+}
+
+static int imx681_enum_frame_size(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state,
+ struct v4l2_subdev_frame_size_enum *fse)
+{
+ if (fse->index > 0)
+ return -EINVAL;
+
+ if (!imx681_is_valid_mbus_code(fse->code))
+ return -EINVAL;
+
+ fse->min_width = IMX681_WIDTH;
+ fse->max_width = IMX681_WIDTH;
+ fse->min_height = IMX681_HEIGHT;
+ fse->max_height = IMX681_HEIGHT;
+
+ return 0;
+}
+
+static int imx681_init_state(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state)
+{
+ struct v4l2_mbus_framefmt *format;
+
+ format = v4l2_subdev_state_get_format(state, IMAGE_PAD);
+ format->width = IMX681_WIDTH;
+ format->height = IMX681_HEIGHT;
+ format->code = MEDIA_BUS_FMT_SGRBG10_1X10;
+ format->field = V4L2_FIELD_NONE;
+ format->colorspace = V4L2_COLORSPACE_RAW;
+ format->ycbcr_enc = V4L2_YCBCR_ENC_601;
+ format->quantization = V4L2_QUANTIZATION_FULL_RANGE;
+ format->xfer_func = V4L2_XFER_FUNC_NONE;
+
+ return 0;
+}
+
+static int imx681_set_pad_format(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state,
+ struct v4l2_subdev_format *fmt)
+{
+ struct v4l2_mbus_framefmt *format;
+
+ /* Fixed resolution, fixed Bayer order */
+ fmt->format.width = IMX681_WIDTH;
+ fmt->format.height = IMX681_HEIGHT;
+ if (!imx681_is_valid_mbus_code(fmt->format.code))
+ fmt->format.code = imx681_mbus_codes[0];
+ fmt->format.field = V4L2_FIELD_NONE;
+ fmt->format.colorspace = V4L2_COLORSPACE_RAW;
+ fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_601;
+ fmt->format.quantization = V4L2_QUANTIZATION_FULL_RANGE;
+ fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;
+
+ format = v4l2_subdev_state_get_format(state, fmt->pad);
+ *format = fmt->format;
+
+ return 0;
+}
+
+static int imx681_get_selection(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state,
+ struct v4l2_subdev_selection *sel)
+{
+ switch (sel->target) {
+ case V4L2_SEL_TGT_CROP:
+ case V4L2_SEL_TGT_CROP_DEFAULT:
+ case V4L2_SEL_TGT_CROP_BOUNDS:
+ case V4L2_SEL_TGT_NATIVE_SIZE:
+ sel->r.top = 0;
+ sel->r.left = 0;
+ sel->r.width = IMX681_WIDTH;
+ sel->r.height = IMX681_HEIGHT;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int imx681_start_streaming(struct imx681 *imx681)
+{
+ int ret;
+
+ dev_dbg(imx681->dev, "starting stream: %dx%d RAW10 2-lane\n",
+ IMX681_WIDTH, IMX681_HEIGHT);
+
+ /* Write init register sequence */
+ ret = cci_multi_reg_write(imx681->cci, imx681_init_regs,
+ ARRAY_SIZE(imx681_init_regs), NULL);
+ if (ret) {
+ dev_err(imx681->dev, "failed to write init regs: %d\n", ret);
+ return ret;
+ }
+
+ dev_dbg(imx681->dev, "init registers written successfully\n");
+
+ /* Wait for sensor to stabilise after configuration */
+ usleep_range(IMX681_INIT_DELAY_US, IMX681_INIT_DELAY_US + 1000);
+
+ /* Apply first exposure settings with group hold */
+ ret = cci_multi_reg_write(imx681->cci, imx681_first_exposure,
+ ARRAY_SIZE(imx681_first_exposure), NULL);
+ if (ret) {
+ dev_err(imx681->dev, "failed to write exposure: %d\n", ret);
+ return ret;
+ }
+
+ /* Apply any pending V4L2 control values */
+ ret = __v4l2_ctrl_handler_setup(imx681->sd.ctrl_handler);
+ if (ret) {
+ dev_err(imx681->dev, "failed to apply controls: %d\n", ret);
+ return ret;
+ }
+
+ /* Start streaming */
+ ret = cci_write(imx681->cci, IMX681_REG_MODE_SELECT,
+ IMX681_MODE_STREAMING, NULL);
+ if (ret) {
+ dev_err(imx681->dev, "failed to start streaming: %d\n", ret);
+ return ret;
+ }
+
+ dev_dbg(imx681->dev, "streaming started\n");
+ return 0;
+}
+
+static int imx681_stop_streaming(struct imx681 *imx681)
+{
+ int ret;
+
+ ret = cci_write(imx681->cci, IMX681_REG_MODE_SELECT,
+ IMX681_MODE_STANDBY, NULL);
+ if (ret)
+ dev_err(imx681->dev, "failed to stop streaming: %d\n", ret);
+
+ return ret;
+}
+
+static int imx681_enable_streams(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state,
+ u32 pad, u64 streams_mask)
+{
+ struct imx681 *imx681 = to_imx681(sd);
+ int ret;
+
+ if (pad != IMAGE_PAD)
+ return -EINVAL;
+
+ ret = pm_runtime_get_sync(imx681->dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(imx681->dev);
+ return ret;
+ }
+
+ ret = imx681_start_streaming(imx681);
+ if (ret)
+ pm_runtime_put_autosuspend(imx681->dev);
+
+ return ret;
+}
+
+static int imx681_disable_streams(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *state,
+ u32 pad, u64 streams_mask)
+{
+ struct imx681 *imx681 = to_imx681(sd);
+
+ if (pad != IMAGE_PAD)
+ return -EINVAL;
+
+ imx681_stop_streaming(imx681);
+ pm_runtime_put_autosuspend(imx681->dev);
+
+ return 0;
+}
+
+static const struct v4l2_subdev_video_ops imx681_video_ops = {
+ .s_stream = v4l2_subdev_s_stream_helper,
+};
+
+static const struct v4l2_subdev_pad_ops imx681_pad_ops = {
+ .enum_mbus_code = imx681_enum_mbus_code,
+ .get_fmt = v4l2_subdev_get_fmt,
+ .set_fmt = imx681_set_pad_format,
+ .get_selection = imx681_get_selection,
+ .enum_frame_size = imx681_enum_frame_size,
+ .enable_streams = imx681_enable_streams,
+ .disable_streams = imx681_disable_streams,
+};
+
+static const struct v4l2_subdev_ops imx681_subdev_ops = {
+ .video = &imx681_video_ops,
+ .pad = &imx681_pad_ops,
+};
+
+static const struct v4l2_subdev_internal_ops imx681_internal_ops = {
+ .init_state = imx681_init_state,
+};
+
+/* Power management */
+static int imx681_power_on(struct device *dev)
+{
+ struct v4l2_subdev *sd = dev_get_drvdata(dev);
+ struct imx681 *imx681 = to_imx681(sd);
+ int ret;
+
+ dev_dbg(imx681->dev, "power on\n");
+
+ ret = regulator_bulk_enable(IMX681_NUM_SUPPLIES, imx681->supplies);
+ if (ret) {
+ dev_err(imx681->dev, "failed to enable regulators: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(imx681->xclk);
+ if (ret) {
+ dev_err(imx681->dev, "failed to enable clock: %d\n", ret);
+ goto err_reg_disable;
+ }
+
+ /* Deassert reset (active low) */
+ gpiod_set_value_cansleep(imx681->reset_gpio, 0);
+
+ usleep_range(IMX681_RESET_DELAY_US,
+ IMX681_RESET_DELAY_US + IMX681_RESET_DELAY_RANGE_US);
+
+ return 0;
+
+err_reg_disable:
+ regulator_bulk_disable(IMX681_NUM_SUPPLIES, imx681->supplies);
+ return ret;
+}
+
+static int imx681_power_off(struct device *dev)
+{
+ struct v4l2_subdev *sd = dev_get_drvdata(dev);
+ struct imx681 *imx681 = to_imx681(sd);
+
+ dev_dbg(imx681->dev, "power off\n");
+
+ /* Assert reset */
+ gpiod_set_value_cansleep(imx681->reset_gpio, 1);
+ clk_disable_unprepare(imx681->xclk);
+ regulator_bulk_disable(IMX681_NUM_SUPPLIES, imx681->supplies);
+
+ return 0;
+}
+
+static int imx681_identify_module(struct imx681 *imx681)
+{
+ u64 val;
+ int ret;
+
+ ret = cci_read(imx681->cci, IMX681_REG_CHIP_ID, &val, NULL);
+ if (ret) {
+ dev_err(imx681->dev,
+ "failed to read chip ID register 0x0016: %d\n", ret);
+ return ret;
+ }
+
+ if (val != IMX681_CHIP_ID) {
+ dev_err(imx681->dev, "chip ID mismatch: 0x%04llx != 0x%04x\n",
+ val, IMX681_CHIP_ID);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int imx681_init_controls(struct imx681 *imx681)
+{
+ struct v4l2_ctrl_handler *ctrl_hdlr = &imx681->ctrl_handler;
+ struct v4l2_fwnode_device_properties props;
+ struct v4l2_ctrl *link_freq;
+ s64 hblank, vblank;
+ int ret;
+
+ ret = v4l2_ctrl_handler_init(ctrl_hdlr, 9);
+ if (ret)
+ return ret;
+
+ /* Pixel rate (read-only) */
+ v4l2_ctrl_new_std(ctrl_hdlr, &imx681_ctrl_ops,
+ V4L2_CID_PIXEL_RATE, IMX681_PIXEL_RATE,
+ IMX681_PIXEL_RATE, 1, IMX681_PIXEL_RATE);
+
+ /* Link frequency (read-only) */
+ link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr, &imx681_ctrl_ops,
+ V4L2_CID_LINK_FREQ,
+ __fls(imx681->link_freq_bitmap),
+ __ffs(imx681->link_freq_bitmap),
+ imx681_link_frequencies);
+ if (link_freq)
+ link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+ /* Horizontal blanking (read-only, fixed) */
+ hblank = IMX681_LINE_LENGTH_PCK - IMX681_WIDTH;
+ imx681->hblank = v4l2_ctrl_new_std(ctrl_hdlr, &imx681_ctrl_ops,
+ V4L2_CID_HBLANK, hblank, hblank,
+ 1, hblank);
+ if (imx681->hblank)
+ imx681->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+ /* Vertical blanking (writable to allow longer exposures) */
+ vblank = IMX681_FRAME_LENGTH_LINES - IMX681_HEIGHT;
+ imx681->vblank = v4l2_ctrl_new_std(ctrl_hdlr, &imx681_ctrl_ops,
+ V4L2_CID_VBLANK, vblank,
+ IMX681_FRAME_LENGTH_MAX - IMX681_HEIGHT,
+ 1, vblank);
+
+ /* Exposure */
+ imx681->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &imx681_ctrl_ops,
+ V4L2_CID_EXPOSURE,
+ IMX681_EXPOSURE_MIN,
+ IMX681_EXPOSURE_MAX, 1,
+ IMX681_EXPOSURE_DEFAULT);
+
+ /* Analog gain */
+ v4l2_ctrl_new_std(ctrl_hdlr, &imx681_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
+ IMX681_ANA_GAIN_MIN, IMX681_ANA_GAIN_MAX, 1,
+ IMX681_ANA_GAIN_DEFAULT);
+
+ /* Digital gain */
+ v4l2_ctrl_new_std(ctrl_hdlr, &imx681_ctrl_ops, V4L2_CID_DIGITAL_GAIN,
+ IMX681_DIG_GAIN_MIN, IMX681_DIG_GAIN_MAX, 1,
+ IMX681_DIG_GAIN_DEFAULT);
+
+ /* Test pattern */
+ v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &imx681_ctrl_ops,
+ V4L2_CID_TEST_PATTERN,
+ ARRAY_SIZE(imx681_test_pattern_menu) - 1,
+ 0, 0, imx681_test_pattern_menu);
+
+ if (ctrl_hdlr->error) {
+ ret = ctrl_hdlr->error;
+ dev_err(imx681->dev, "control init failed: %d\n", ret);
+ goto error;
+ }
+
+ ret = v4l2_fwnode_device_parse(imx681->dev, &props);
+ if (ret)
+ goto error;
+
+ ret = v4l2_ctrl_new_fwnode_properties(ctrl_hdlr, &imx681_ctrl_ops,
+ &props);
+ if (ret)
+ goto error;
+
+ imx681->sd.ctrl_handler = ctrl_hdlr;
+ return 0;
+
+error:
+ v4l2_ctrl_handler_free(ctrl_hdlr);
+ return ret;
+}
+
+static int imx681_parse_endpoint(struct imx681 *imx681)
+{
+ struct fwnode_handle *fwnode = dev_fwnode(imx681->dev);
+ struct v4l2_fwnode_endpoint bus_cfg = {
+ .bus_type = V4L2_MBUS_CSI2_DPHY,
+ };
+ struct fwnode_handle *ep;
+ int ret;
+
+ ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
+ if (!ep) {
+ dev_err(imx681->dev, "no endpoint found in firmware node\n");
+ return -ENXIO;
+ }
+
+ ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
+ fwnode_handle_put(ep);
+ if (ret) {
+ dev_err(imx681->dev, "failed to parse endpoint: %d\n", ret);
+ return ret;
+ }
+
+ if (bus_cfg.bus.mipi_csi2.num_data_lanes != IMX681_NUM_LANES) {
+ dev_err(imx681->dev,
+ "expected %d data lanes, got %d\n",
+ IMX681_NUM_LANES,
+ bus_cfg.bus.mipi_csi2.num_data_lanes);
+ ret = -EINVAL;
+ goto done;
+ }
+
+ ret = v4l2_link_freq_to_bitmap(imx681->dev,
+ bus_cfg.link_frequencies,
+ bus_cfg.nr_of_link_frequencies,
+ imx681_link_frequencies,
+ ARRAY_SIZE(imx681_link_frequencies),
+ &imx681->link_freq_bitmap);
+ if (ret)
+ dev_err(imx681->dev, "link frequency mismatch: %d\n", ret);
+
+done:
+ v4l2_fwnode_endpoint_free(&bus_cfg);
+ return ret;
+}
+
+static int imx681_probe(struct i2c_client *client)
+{
+ struct imx681 *imx681;
+ unsigned int i;
+ int ret;
+
+ imx681 = devm_kzalloc(&client->dev, sizeof(*imx681), GFP_KERNEL);
+ if (!imx681)
+ return -ENOMEM;
+
+ imx681->dev = &client->dev;
+
+ /* Initialise V4L2 subdev */
+ v4l2_i2c_subdev_init(&imx681->sd, client, &imx681_subdev_ops);
+
+ /* Initialise CCI regmap for 16-bit register addresses */
+ imx681->cci = devm_cci_regmap_init_i2c(client, 16);
+ if (IS_ERR(imx681->cci)) {
+ ret = PTR_ERR(imx681->cci);
+ dev_err(imx681->dev, "failed to init CCI: %d\n", ret);
+ return ret;
+ }
+
+ /* Get clock (optional - INT3472 provides it on Surface devices) */
+ imx681->xclk = devm_clk_get_optional(imx681->dev, NULL);
+ if (IS_ERR(imx681->xclk))
+ return dev_err_probe(imx681->dev, PTR_ERR(imx681->xclk),
+ "failed to get clock\n");
+
+ if (imx681->xclk)
+ dev_dbg(imx681->dev, "clock rate: %lu Hz\n",
+ clk_get_rate(imx681->xclk));
+
+ /* Get regulators */
+ for (i = 0; i < IMX681_NUM_SUPPLIES; i++)
+ imx681->supplies[i].supply = imx681_supply_names[i];
+
+ ret = devm_regulator_bulk_get(imx681->dev, IMX681_NUM_SUPPLIES,
+ imx681->supplies);
+ if (ret)
+ return dev_err_probe(imx681->dev, ret,
+ "failed to get regulators\n");
+
+ /* Get reset GPIO (optional) */
+ imx681->reset_gpio = devm_gpiod_get_optional(imx681->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(imx681->reset_gpio))
+ return dev_err_probe(imx681->dev,
+ PTR_ERR(imx681->reset_gpio),
+ "failed to get reset GPIO\n");
+
+ /* Parse CSI-2 endpoint */
+ ret = imx681_parse_endpoint(imx681);
+ if (ret) {
+ dev_err(imx681->dev, "endpoint parse failed: %d\n", ret);
+ return ret;
+ }
+
+ /* Power on and verify chip ID */
+ ret = imx681_power_on(imx681->dev);
+ if (ret) {
+ dev_err(imx681->dev, "power on failed: %d\n", ret);
+ return ret;
+ }
+
+ ret = imx681_identify_module(imx681);
+ if (ret)
+ goto error_power_off;
+
+ /* Enable runtime PM */
+ pm_runtime_set_active(imx681->dev);
+ pm_runtime_get_noresume(imx681->dev);
+ pm_runtime_enable(imx681->dev);
+ pm_runtime_set_autosuspend_delay(imx681->dev, 1000);
+ pm_runtime_use_autosuspend(imx681->dev);
+
+ /* Init V4L2 controls */
+ ret = imx681_init_controls(imx681);
+ if (ret)
+ goto error_pm;
+
+ /* Setup subdev */
+ imx681->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+ imx681->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+ imx681->sd.internal_ops = &imx681_internal_ops;
+
+ /* Init media entity */
+ imx681->pad.flags = MEDIA_PAD_FL_SOURCE;
+ ret = media_entity_pads_init(&imx681->sd.entity, 1, &imx681->pad);
+ if (ret) {
+ dev_err(imx681->dev, "media entity init failed: %d\n", ret);
+ goto error_handler_free;
+ }
+
+ imx681->sd.state_lock = imx681->ctrl_handler.lock;
+ ret = v4l2_subdev_init_finalize(&imx681->sd);
+ if (ret < 0) {
+ dev_err(imx681->dev, "subdev init finalize failed: %d\n", ret);
+ goto error_media_entity;
+ }
+
+ ret = v4l2_async_register_subdev_sensor(&imx681->sd);
+ if (ret < 0) {
+ dev_err(imx681->dev,
+ "async register subdev failed: %d\n", ret);
+ goto error_subdev_cleanup;
+ }
+
+ pm_runtime_put_autosuspend(imx681->dev);
+
+ dev_info(imx681->dev,
+ "IMX681 probed successfully: %dx%d @ %lld Hz link freq\n",
+ IMX681_WIDTH, IMX681_HEIGHT, IMX681_LINK_FREQ);
+
+ return 0;
+
+error_subdev_cleanup:
+ v4l2_subdev_cleanup(&imx681->sd);
+error_media_entity:
+ media_entity_cleanup(&imx681->sd.entity);
+error_handler_free:
+ v4l2_ctrl_handler_free(imx681->sd.ctrl_handler);
+error_pm:
+ pm_runtime_disable(imx681->dev);
+ pm_runtime_put_noidle(imx681->dev);
+ pm_runtime_set_suspended(imx681->dev);
+error_power_off:
+ imx681_power_off(imx681->dev);
+ return ret;
+}
+
+static void imx681_remove(struct i2c_client *client)
+{
+ struct v4l2_subdev *sd = i2c_get_clientdata(client);
+ struct imx681 *imx681 = to_imx681(sd);
+
+ v4l2_async_unregister_subdev(sd);
+ v4l2_subdev_cleanup(&imx681->sd);
+ media_entity_cleanup(&sd->entity);
+ v4l2_ctrl_handler_free(imx681->sd.ctrl_handler);
+
+ pm_runtime_disable(imx681->dev);
+ if (!pm_runtime_status_suspended(imx681->dev))
+ imx681_power_off(imx681->dev);
+ pm_runtime_set_suspended(imx681->dev);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(imx681_pm_ops, imx681_power_off,
+ imx681_power_on, NULL);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id imx681_acpi_ids[] = {
+ { "SONY0681" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, imx681_acpi_ids);
+#endif
+
+static const struct of_device_id imx681_dt_ids[] = {
+ { .compatible = "sony,imx681" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx681_dt_ids);
+
+static struct i2c_driver imx681_i2c_driver = {
+ .driver = {
+ .name = "imx681",
+ .pm = pm_ptr(&imx681_pm_ops),
+ .acpi_match_table = ACPI_PTR(imx681_acpi_ids),
+ .of_match_table = imx681_dt_ids,
+ },
+ .probe = imx681_probe,
+ .remove = imx681_remove,
+};
+module_i2c_driver(imx681_i2c_driver);
+
+MODULE_DESCRIPTION("Sony IMX681 CMOS Image Sensor Driver");
+MODULE_AUTHOR("Andre Gilerson <andre.gilerson@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.53.0