[PATCH v1] media: i2c: add lt6911uxe hdmi bridge driver

[Dongcheng Yan <dongcheng.yan@xxxxxxxxx>]

Lontium LT9611UXE is a HDMI to MIPI CSI-2 bridge,
It supports modes up to 4k60fps, switches current mode when
plugging HDMI or changing the source active signal mode.

Signed-off-by: Dongcheng Yan <dongcheng.yan@xxxxxxxxx>
---
 drivers/media/i2c/Kconfig     |  12 +
 drivers/media/i2c/Makefile    |   1 +
 drivers/media/i2c/lt6911uxe.c | 667 ++++++++++++++++++++++++++++++++++
 3 files changed, 680 insertions(+)
 create mode 100644 drivers/media/i2c/lt6911uxe.c

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index c6d3ee472d81..abd7faaae305 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1494,6 +1494,18 @@ config VIDEO_I2C
 	  To compile this driver as a module, choose M here: the
 	  module will be called video-i2c
 
+config VIDEO_LT6911UXE
+        tristate "Lontium LT6911UXE decoder"
+        depends on ACPI && VIDEO_DEV
+        select V4L2_FWNODE
+        select V4L2_CCI_I2C
+        help
+          This is a Video4Linux2 sensor-level driver for the Lontium
+          LT6911UXE HDMI to MIPI CSI-2 bridge.
+
+          To compile this driver as a module, choose M here: the
+          module will be called lt6911uxe.
+
 config VIDEO_M52790
 	tristate "Mitsubishi M52790 A/V switch"
 	depends on VIDEO_DEV && I2C
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index dfbe6448b549..87005dafa079 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
 obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
 obj-$(CONFIG_VIDEO_LM3560) += lm3560.o
 obj-$(CONFIG_VIDEO_LM3646) += lm3646.o
+obj-$(CONFIG_VIDEO_LT6911UXE) += lt6911uxe.o
 obj-$(CONFIG_VIDEO_M52790) += m52790.o
 obj-$(CONFIG_VIDEO_MAX9271_LIB) += max9271.o
 obj-$(CONFIG_VIDEO_MAX9286) += max9286.o
diff --git a/drivers/media/i2c/lt6911uxe.c b/drivers/media/i2c/lt6911uxe.c
new file mode 100644
index 000000000000..11ad78b83137
--- /dev/null
+++ b/drivers/media/i2c/lt6911uxe.c
@@ -0,0 +1,667 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2023 - 2024 Intel Corporation.
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <media/v4l2-cci.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fwnode.h>
+
+#define LT6911UXE_CHIP_ID		0x2102
+#define REG_CHIP_ID_H			CCI_REG8(0xe100)
+#define REG_CHIP_ID_L			CCI_REG8(0xe101)
+
+#define REG_ENABLE_I2C			CCI_REG8(0xe0ee)
+#define REG_PIX_CLK			CCI_REG24(0xe085)
+#define REG_BYTE_CLK			CCI_REG24(0xe092)
+#define REG_H_TOTAL			CCI_REG16(0xe088)
+#define REG_V_TOTAL			CCI_REG16(0xe08a)
+#define REG_HALF_H_ACTIVE		CCI_REG16(0xe08c)
+#define REG_V_ACTIVE			CCI_REG16(0xe08e)
+#define REG_MIPI_FORMAT			CCI_REG8(0xe096)
+#define REG_MIPI_TX_CTRL		CCI_REG8(0xe0b0)
+
+/* Interrupts */
+#define REG_INT_HDMI			CCI_REG8(0xe084)
+#define INT_VIDEO_DISAPPEAR		0x0
+#define INT_VIDEO_READY			0x1
+
+#define LT6911UXE_DEFAULT_WIDTH		3840
+#define LT6911UXE_DEFAULT_HEIGHT	2160
+#define LT6911UXE_DEFAULT_LANES		4
+#define LT6911UXE_DEFAULT_FPS		30
+#define LT6911UXE_MAX_LINK_FREQ		297000000
+#define LT9611_PAGE_CONTROL		0xff
+#define YUV422_8_BIT			0x7
+
+static const struct regmap_range_cfg lt9611uxe_ranges[] = {
+	{
+		.name = "register_range",
+		.range_min =  0,
+		.range_max = 0xffff,
+		.selector_reg = LT9611_PAGE_CONTROL,
+		.selector_mask = 0xff,
+		.selector_shift = 0,
+		.window_start = 0,
+		.window_len = 0x100,
+	},
+};
+
+static const struct regmap_config lt9611uxe_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xffff,
+	.ranges = lt9611uxe_ranges,
+	.num_ranges = ARRAY_SIZE(lt9611uxe_ranges),
+};
+
+struct lt6911uxe_mode {
+	u32 width;
+	u32 height;
+	u32 code;
+	u32 fps;
+	u32 lanes;
+	s64 link_freq;
+};
+
+struct lt6911uxe {
+	struct v4l2_subdev sd;
+	struct media_pad pad;
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct v4l2_ctrl *pixel_rate;
+	struct v4l2_ctrl *link_freq;
+
+	struct lt6911uxe_mode cur_mode;
+	struct regmap *regmap;
+	unsigned int irq_pin_flags;
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *irq_gpio;
+	struct mutex mutex;
+};
+
+static const struct v4l2_event lt6911uxe_ev_source_change = {
+	.type = V4L2_EVENT_SOURCE_CHANGE,
+	.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
+};
+
+static const struct v4l2_event lt6911uxe_ev_stream_end = {
+	.type = V4L2_EVENT_EOS,
+};
+
+static inline struct lt6911uxe *to_lt6911uxe(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct lt6911uxe, sd);
+}
+
+static const struct lt6911uxe_mode default_mode = {
+	.width = LT6911UXE_DEFAULT_WIDTH,
+	.height = LT6911UXE_DEFAULT_HEIGHT,
+	.code = MEDIA_BUS_FMT_UYVY8_1X16,
+	.fps = LT6911UXE_DEFAULT_FPS,
+	.lanes = LT6911UXE_DEFAULT_LANES,
+	.link_freq = LT6911UXE_MAX_LINK_FREQ,
+};
+
+static s64 get_pixel_rate(struct lt6911uxe *lt6911uxe)
+{
+	s64 pixel_rate;
+
+	pixel_rate = (s64)lt6911uxe->cur_mode.width *
+		     lt6911uxe->cur_mode.height *
+		     lt6911uxe->cur_mode.fps * 16;
+	do_div(pixel_rate, lt6911uxe->cur_mode.lanes);
+
+	return pixel_rate;
+}
+
+static int lt6911uxe_status_update(struct lt6911uxe *lt6911uxe)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&lt6911uxe->sd);
+	u64 int_event;
+	u64 byte_clk, pixel_clk, fps, format;
+	u64 htotal, vtotal, half_width, height;
+	int ret = 0;
+
+	/* Read interrupt event */
+	cci_read(lt6911uxe->regmap, REG_INT_HDMI, &int_event, &ret);
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+				     "failed to read interrupt event\n");
+
+	switch (int_event) {
+	case INT_VIDEO_READY:
+		cci_read(lt6911uxe->regmap, REG_BYTE_CLK, &byte_clk, &ret);
+		byte_clk *= 1000;
+		cci_read(lt6911uxe->regmap, REG_PIX_CLK, &pixel_clk, &ret);
+		pixel_clk *= 1000;
+
+		if (ret || byte_clk == 0 || pixel_clk == 0) {
+			dev_err(&client->dev,
+				"invalid ByteClock or PixelClock\n");
+			return -EINVAL;
+		}
+
+		cci_read(lt6911uxe->regmap, REG_H_TOTAL, &htotal, &ret);
+		cci_read(lt6911uxe->regmap, REG_V_TOTAL, &vtotal, &ret);
+		if (ret || htotal == 0 || vtotal == 0) {
+			dev_err(&client->dev, "invalid htotal or vtotal\n");
+			return -EINVAL;
+		}
+
+		fps = div_u64(pixel_clk, htotal * vtotal);
+		if (fps > 60) {
+			dev_err(&client->dev,
+				"max fps is 60, current fps: %llu\n", fps);
+			return -EINVAL;
+		}
+
+		cci_read(lt6911uxe->regmap, REG_HALF_H_ACTIVE,
+			 &half_width, &ret);
+		cci_read(lt6911uxe->regmap, REG_V_ACTIVE, &height, &ret);
+		if (ret || half_width == 0 || half_width * 2 > 3840 ||
+		    height == 0 || height > 2160) {
+			dev_err(&client->dev, "invalid width or height\n");
+			return -EINVAL;
+		}
+
+		/*
+		 * Get MIPI format, YUV422_8_BIT is expected in lt6911uxe
+		 */
+		cci_read(lt6911uxe->regmap, REG_MIPI_FORMAT, &format, &ret);
+		if (format != YUV422_8_BIT) {
+			dev_err(&client->dev, "invalid MIPI format\n");
+			return -EINVAL;
+		}
+		lt6911uxe->cur_mode.height = height;
+		lt6911uxe->cur_mode.width = half_width * 2;
+		lt6911uxe->cur_mode.fps = fps;
+		/* MIPI Clock Rate = ByteClock × 4, defined in lt6911uxe spec */
+		lt6911uxe->cur_mode.link_freq = byte_clk * 4;
+		v4l2_subdev_notify_event(&lt6911uxe->sd,
+					 &lt6911uxe_ev_source_change);
+		break;
+
+	case INT_VIDEO_DISAPPEAR:
+		cci_write(lt6911uxe->regmap, REG_MIPI_TX_CTRL, 0x0, NULL);
+		lt6911uxe->cur_mode.height = 0;
+		lt6911uxe->cur_mode.width = 0;
+		lt6911uxe->cur_mode.fps = 0;
+		lt6911uxe->cur_mode.link_freq = 0;
+		v4l2_subdev_notify_event(&lt6911uxe->sd,
+					 &lt6911uxe_ev_stream_end);
+		break;
+
+	default:
+		return  -ENOLINK;
+	}
+
+	return ret;
+}
+
+static int lt6911uxe_init_controls(struct lt6911uxe *lt6911uxe)
+{
+	struct v4l2_ctrl_handler *ctrl_hdlr;
+	s64 pixel_rate;
+	int ret;
+
+	ctrl_hdlr = &lt6911uxe->ctrl_handler;
+	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 8);
+	if (ret)
+		return ret;
+
+	ctrl_hdlr->lock = &lt6911uxe->mutex;
+	lt6911uxe->link_freq = v4l2_ctrl_new_std(ctrl_hdlr, NULL,
+						 V4L2_CID_CUR_LINK_FREQ, 0,
+						 LT6911UXE_MAX_LINK_FREQ, 1,
+						 lt6911uxe->cur_mode.link_freq);
+
+	pixel_rate = get_pixel_rate(lt6911uxe);
+	lt6911uxe->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, NULL,
+						  V4L2_CID_PIXEL_RATE,
+						  pixel_rate, pixel_rate, 1,
+						  pixel_rate);
+
+	if (ctrl_hdlr->error) {
+		ret = ctrl_hdlr->error;
+		goto hdlr_free;
+	}
+	lt6911uxe->sd.ctrl_handler = ctrl_hdlr;
+
+	return 0;
+
+hdlr_free:
+	v4l2_ctrl_handler_free(ctrl_hdlr);
+	return ret;
+}
+
+static void lt6911uxe_update_pad_format(const struct lt6911uxe_mode *mode,
+					struct v4l2_mbus_framefmt *fmt)
+{
+	fmt->width = mode->width;
+	fmt->height = mode->height;
+	fmt->code = mode->code;
+	fmt->field = V4L2_FIELD_NONE;
+}
+
+static int lt6911uxe_start_streaming(struct lt6911uxe *lt6911uxe)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&lt6911uxe->sd);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(&client->dev);
+	if (ret < 0)
+		return ret;
+
+	cci_write(lt6911uxe->regmap, REG_MIPI_TX_CTRL, 0x1, &ret);
+	if (ret) {
+		dev_err(&client->dev, "failed to start stream\n");
+		goto err_rpm_put;
+	}
+
+	return 0;
+
+err_rpm_put:
+	pm_runtime_put(&client->dev);
+	return ret;
+}
+
+static int lt6911uxe_enable_streams(struct v4l2_subdev *sd,
+				    struct v4l2_subdev_state *state,
+				    u32 pad, u64 streams_mask)
+{
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+	int ret;
+
+	if (pad != 0)
+		return -EINVAL;
+
+	mutex_lock(&lt6911uxe->mutex);
+	ret = lt6911uxe_start_streaming(lt6911uxe);
+	mutex_unlock(&lt6911uxe->mutex);
+
+	return ret;
+}
+
+static int lt6911uxe_disable_streams(struct v4l2_subdev *sd,
+				     struct v4l2_subdev_state *state,
+				     u32 pad, u64 streams_mask)
+{
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+	struct i2c_client *client = v4l2_get_subdevdata(&lt6911uxe->sd);
+	int ret;
+
+	if (pad != 0)
+		return -EINVAL;
+
+	mutex_lock(&lt6911uxe->mutex);
+	ret = cci_write(lt6911uxe->regmap, REG_MIPI_TX_CTRL, 0x0, NULL);
+	if (ret)
+		dev_err(&client->dev, "failed to stop stream\n");
+	mutex_unlock(&lt6911uxe->mutex);
+
+	return ret;
+}
+
+static int lt6911uxe_set_format(struct v4l2_subdev *sd,
+				struct v4l2_subdev_state *sd_state,
+				struct v4l2_subdev_format *fmt)
+{
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+	u64 pixel_rate;
+
+	mutex_lock(&lt6911uxe->mutex);
+	lt6911uxe_update_pad_format(&lt6911uxe->cur_mode, &fmt->format);
+	*v4l2_subdev_state_get_format(sd_state, fmt->pad) = fmt->format;
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		mutex_unlock(&lt6911uxe->mutex);
+		return 0;
+	}
+
+	pixel_rate = get_pixel_rate(lt6911uxe);
+	__v4l2_ctrl_modify_range(lt6911uxe->pixel_rate, pixel_rate,
+				 pixel_rate, 1, pixel_rate);
+
+	mutex_unlock(&lt6911uxe->mutex);
+	return 0;
+}
+
+static int lt6911uxe_enum_mbus_code(struct v4l2_subdev *sd,
+				    struct v4l2_subdev_state *sd_state,
+				    struct v4l2_subdev_mbus_code_enum *code)
+{
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+
+	if (code->pad || code->index)
+		return -EINVAL;
+
+	code->code = lt6911uxe->cur_mode.code;
+
+	return 0;
+}
+
+static int lt6911uxe_enum_frame_size(struct v4l2_subdev *sd,
+				     struct v4l2_subdev_state *sd_state,
+				     struct v4l2_subdev_frame_size_enum *fse)
+{
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+
+	if (fse->index != 0)
+		return -EINVAL;
+
+	if (fse->code != MEDIA_BUS_FMT_UYVY8_1X16)
+		return -EINVAL;
+
+	fse->min_width = lt6911uxe->cur_mode.width;
+	fse->max_width = fse->min_width;
+	fse->min_height = lt6911uxe->cur_mode.height;
+	fse->max_height = fse->min_height;
+
+	return 0;
+}
+
+static int lt6911uxe_enum_frame_interval(struct v4l2_subdev *sd,
+		struct v4l2_subdev_state *sd_state,
+		struct v4l2_subdev_frame_interval_enum *fie)
+{
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+
+	if (fie->index != 0)
+		return -EINVAL;
+
+	fie->interval.numerator = 1;
+	fie->interval.denominator = lt6911uxe->cur_mode.fps;
+
+	return 0;
+}
+
+static int lt6911uxe_init_state(struct v4l2_subdev *sd,
+				struct v4l2_subdev_state *sd_state)
+{
+	struct v4l2_subdev_format fmt = {
+		.which = V4L2_SUBDEV_FORMAT_TRY,
+		.pad = 0,
+		.format = {
+			.code = MEDIA_BUS_FMT_UYVY8_1X16,
+			.width = LT6911UXE_DEFAULT_WIDTH,
+			.height = LT6911UXE_DEFAULT_HEIGHT,
+		},
+	};
+	int ret;
+
+	ret = lt6911uxe_set_format(sd, sd_state, &fmt);
+
+	return ret;
+}
+
+static const struct v4l2_subdev_video_ops lt6911uxe_video_ops = {
+	.s_stream = v4l2_subdev_s_stream_helper,
+};
+
+static const struct v4l2_subdev_pad_ops lt6911uxe_pad_ops = {
+	.set_fmt = lt6911uxe_set_format,
+	.get_fmt = v4l2_subdev_get_fmt,
+	.enable_streams = lt6911uxe_enable_streams,
+	.disable_streams = lt6911uxe_disable_streams,
+	.enum_mbus_code = lt6911uxe_enum_mbus_code,
+	.enum_frame_size = lt6911uxe_enum_frame_size,
+	.enum_frame_interval = lt6911uxe_enum_frame_interval,
+};
+
+static const struct v4l2_subdev_core_ops lt6911uxe_subdev_core_ops = {
+	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
+	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
+static const struct v4l2_subdev_ops lt6911uxe_subdev_ops = {
+	.core = &lt6911uxe_subdev_core_ops,
+	.video = &lt6911uxe_video_ops,
+	.pad = &lt6911uxe_pad_ops,
+};
+
+static const struct media_entity_operations lt6911uxe_subdev_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static const struct v4l2_subdev_internal_ops lt6911uxe_internal_ops = {
+	.init_state = lt6911uxe_init_state,
+};
+
+static int lt6911uxe_fwnode_parse(struct lt6911uxe *lt6911uxe,
+				  struct device *dev)
+{
+	struct fwnode_handle *endpoint;
+	struct v4l2_fwnode_endpoint bus_cfg = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY,
+	};
+	int ret;
+
+	endpoint = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0,
+						   FWNODE_GRAPH_ENDPOINT_NEXT);
+	if (!endpoint) {
+		dev_err(dev, "endpoint node not found\n");
+		return -EPROBE_DEFER;
+	}
+
+	ret = v4l2_fwnode_endpoint_parse(endpoint, &bus_cfg);
+	if (ret) {
+		dev_err(dev, "failed to parse endpoint node\n");
+		goto out_err;
+	}
+
+	/*
+	 * Check the number of MIPI CSI2 data lanes,
+	 * lt6911uxe only support 4 lanes.
+	 */
+	if (bus_cfg.bus.mipi_csi2.num_data_lanes != LT6911UXE_DEFAULT_LANES) {
+		dev_err(dev, "only 4 data lanes are currently supported\n");
+		goto out_err;
+	}
+
+	return 0;
+
+out_err:
+	v4l2_fwnode_endpoint_free(&bus_cfg);
+	fwnode_handle_put(endpoint);
+	return ret;
+}
+
+static int lt6911uxe_identify_module(struct lt6911uxe *lt6911uxe)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&lt6911uxe->sd);
+	u64 val_h, val_l;
+	u16 val;
+	int ret = 0;
+
+	/* Chip ID should be confirmed when the I2C slave is active */
+	cci_write(lt6911uxe->regmap, REG_ENABLE_I2C, 0x1, &ret);
+	cci_read(lt6911uxe->regmap, REG_CHIP_ID_H, &val_h, &ret);
+	cci_read(lt6911uxe->regmap, REG_CHIP_ID_L, &val_l, &ret);
+	cci_write(lt6911uxe->regmap, REG_ENABLE_I2C, 0x0, &ret);
+	if (ret) {
+		dev_err(&client->dev, "fail to read chip id\n");
+		return ret;
+	}
+
+	val = (val_h << 8) | val_l;
+
+	if (val != LT6911UXE_CHIP_ID) {
+		dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
+			LT6911UXE_CHIP_ID, val);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int lt6911uxe_parse_gpio(struct lt6911uxe *lt6911uxe, struct device *dev)
+{
+	lt6911uxe->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_IN);
+	if (IS_ERR(lt6911uxe->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(lt6911uxe->reset_gpio),
+				     "failed to get reset gpio\n");
+
+	lt6911uxe->irq_gpio = devm_gpiod_get(dev, "readystat", GPIOD_IN);
+	if (IS_ERR(lt6911uxe->irq_gpio))
+		return dev_err_probe(dev, PTR_ERR(lt6911uxe->irq_gpio),
+				     "failed to get ready_stat gpio\n");
+
+	return 0;
+}
+
+static irqreturn_t lt6911uxe_threaded_irq_fn(int irq, void *dev_id)
+{
+	struct v4l2_subdev *sd = dev_id;
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+
+	mutex_lock(&lt6911uxe->mutex);
+	lt6911uxe_status_update(lt6911uxe);
+	mutex_unlock(&lt6911uxe->mutex);
+
+	return IRQ_HANDLED;
+}
+
+static void lt6911uxe_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct lt6911uxe *lt6911uxe = to_lt6911uxe(sd);
+
+	free_irq(gpiod_to_irq(lt6911uxe->irq_gpio), lt6911uxe);
+	v4l2_async_unregister_subdev(&lt6911uxe->sd);
+	v4l2_subdev_cleanup(sd);
+	media_entity_cleanup(&lt6911uxe->sd.entity);
+	v4l2_ctrl_handler_free(&lt6911uxe->ctrl_handler);
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+}
+
+static int lt6911uxe_probe(struct i2c_client *client)
+{
+	struct lt6911uxe *lt6911uxe;
+	int ret;
+
+	lt6911uxe = devm_kzalloc(&client->dev, sizeof(*lt6911uxe), GFP_KERNEL);
+	if (!lt6911uxe)
+		return -ENOMEM;
+
+	/* define default mode: 4k@60fps, changed when interrupt occurs. */
+	lt6911uxe->cur_mode = default_mode;
+
+	lt6911uxe->regmap = devm_regmap_init_i2c(client,
+						 &lt9611uxe_regmap_config);
+	if (IS_ERR(lt6911uxe->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(lt6911uxe->regmap),
+				     "failed to init CCI\n");
+
+	ret = lt6911uxe_parse_gpio(lt6911uxe, &client->dev);
+	if (ret)
+		return ret;
+
+	ret = lt6911uxe_fwnode_parse(lt6911uxe, &client->dev);
+	if (ret)
+		return ret;
+
+	usleep_range(10000, 10500);
+
+	ret = lt6911uxe_identify_module(lt6911uxe);
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+				     "failed to find chip\n");
+
+	mutex_init(&lt6911uxe->mutex);
+	v4l2_i2c_subdev_init(&lt6911uxe->sd, client, &lt6911uxe_subdev_ops);
+	ret = lt6911uxe_init_controls(lt6911uxe);
+	if (ret) {
+		dev_info(&client->dev, "failed to init control: %d\n", ret);
+		goto probe_error_v4l2_ctrl_handler_free;
+	}
+
+	lt6911uxe->sd.dev = &client->dev;
+	lt6911uxe->sd.internal_ops = &lt6911uxe_internal_ops;
+	lt6911uxe->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
+			       V4L2_SUBDEV_FL_HAS_EVENTS;
+	lt6911uxe->sd.entity.ops = &lt6911uxe_subdev_entity_ops;
+	lt6911uxe->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	lt6911uxe->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&lt6911uxe->sd.entity, 1, &lt6911uxe->pad);
+	if (ret) {
+		dev_err(&client->dev, "failed to init entity pads: %d\n", ret);
+		goto probe_error_v4l2_ctrl_handler_free;
+	}
+
+	/*
+	 * Device is already turned on by i2c-core with ACPI domain PM.
+	 * Enable runtime PM and turn off the device.
+	 */
+	pm_runtime_set_active(&client->dev);
+	pm_runtime_enable(&client->dev);
+	pm_runtime_idle(&client->dev);
+
+	ret = v4l2_subdev_init_finalize(&lt6911uxe->sd);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to init v4l2 subdev: %d\n", ret);
+		goto probe_error_media_entity_cleanup;
+	}
+
+	ret = v4l2_async_register_subdev_sensor(&lt6911uxe->sd);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to register V4L2 subdev: %d\n",
+			ret);
+		goto rpm;
+	}
+
+	/* Setting irq */
+	lt6911uxe->irq_pin_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
+				   IRQF_ONESHOT;
+
+	ret = request_threaded_irq(gpiod_to_irq(lt6911uxe->irq_gpio), NULL,
+				   lt6911uxe_threaded_irq_fn,
+				   lt6911uxe->irq_pin_flags, NULL, lt6911uxe);
+	if (ret) {
+		dev_err(&client->dev, "failed to request IRQ\n");
+		free_irq(gpiod_to_irq(lt6911uxe->irq_gpio), lt6911uxe);
+		goto rpm;
+	}
+
+	return 0;
+
+rpm:
+	pm_runtime_disable(&client->dev);
+	v4l2_subdev_cleanup(&lt6911uxe->sd);
+
+probe_error_media_entity_cleanup:
+	media_entity_cleanup(&lt6911uxe->sd.entity);
+
+probe_error_v4l2_ctrl_handler_free:
+	v4l2_ctrl_handler_free(lt6911uxe->sd.ctrl_handler);
+	mutex_destroy(&lt6911uxe->mutex);
+	return ret;
+}
+
+static const struct acpi_device_id lt6911uxe_acpi_ids[] = {
+	{ "INTC10C5" },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, lt6911uxe_acpi_ids);
+
+static struct i2c_driver lt6911uxe_i2c_driver = {
+	.driver = {
+		.name = "lt6911uxe",
+		.acpi_match_table = ACPI_PTR(lt6911uxe_acpi_ids),
+	},
+	.probe = lt6911uxe_probe,
+	.remove = lt6911uxe_remove,
+};
+
+module_i2c_driver(lt6911uxe_i2c_driver);
+
+MODULE_AUTHOR("Yan Dongcheng <dongcheng.yan@xxxxxxxxx>");
+MODULE_DESCRIPTION("Lontium lt6911uxe HDMI to MIPI Bridge Driver");
+MODULE_LICENSE("GPL");

base-commit: 6ba59ff4227927d3a8530fc2973b80e94b54d58f
-- 
2.34.1