media: i2c: add driver for ITE IT6625/IT6626

Add a V4L2 subdevice driver for the ITE IT6625/IT6626 HDMI-to-MIPI
CSI-2 bridge chips. IT6625 accepts an HDMI 2.0 input and IT6626 an
HDMI 2.1 input, converting it to a D-PHY (or C/D-PHY on IT6626)
MIPI CSI-2 output. The bridge is configured over I2C, exposes an
HDMI CEC adapter, and supports EDID read/write, DV timings
detection/configuration, and HPD control via the standard V4L2
subdevice pad and video ops.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
[hverkuil: change it6625_v4l2_sd_ctrl_update to a void function]

6 files changed, 2448 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index f0bb3f1b5ebb..f515e1473af9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13965,6 +13965,14 @@ T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
 F:	Documentation/devicetree/bindings/display/bridge/ite,it66121.yaml
 F:	drivers/gpu/drm/bridge/ite-it66121.c
 
+ITE IT6625 HDMI to MIPI MEDIA DRIVER
+M:	Hermes Wu <Hermes.Wu@ite.com.tw>
+S:	Maintained
+T:	git git://linuxtv.org/media.git
+F:	Documentation/devicetree/bindings/media/i2c/ite,it6625.yaml
+F:	drivers/media/i2c/it6625.c
+F:	include/uapi/linux/it6625.h
+
 IVTV VIDEO4LINUX DRIVER
 M:	Andy Walls <awalls@md.metrocast.net>
 L:	linux-media@vger.kernel.org
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index df6a73731803..3370b66ab4ee 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1322,6 +1322,24 @@ config VIDEO_ISL7998X
 	  Support for Intersil ISL7998x analog to MIPI-CSI2 or
 	  BT.656 decoder.
 
+config VIDEO_IT6625
+	tristate "IT6625 HDMI to MIPI CSI bridge"
+	depends on VIDEO_DEV && I2C
+	depends on OF
+	select CEC_CORE
+	select MEDIA_CONTROLLER
+	select REGMAP_I2C
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	  V4L2 subdevice driver for the ITE IT6625/IT6626 HDMI to MIPI
+	  CSI-2 bridge chips. IT6625 accepts an HDMI 2.0 input and
+	  IT6626 an HDMI 2.1 input, converting it to a MIPI CSI-2
+	  output. The driver also exposes an HDMI CEC adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called it6625.
+
 config VIDEO_LT6911UXE
 	tristate "Lontium LT6911UXE decoder"
 	depends on ACPI && VIDEO_DEV && I2C
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 9c7f990a3e66..fd1cb25718c0 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_VIDEO_IMX678) += imx678.o
 obj-$(CONFIG_VIDEO_IMX471) += imx471.o
 obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
 obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
+obj-$(CONFIG_VIDEO_IT6625) += it6625.o
 obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
 obj-$(CONFIG_VIDEO_LM3560) += lm3560.o
 obj-$(CONFIG_VIDEO_LM3646) += lm3646.o
diff --git a/drivers/media/i2c/it6625.c b/drivers/media/i2c/it6625.c
new file mode 100644
index 000000000000..da17e5d5ce9e
--- /dev/null
+++ b/drivers/media/i2c/it6625.c
@@ -0,0 +1,2390 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * it6625 - ite HDMI to MIPI bridge
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/hdmi.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/v4l2-dv-timings.h>
+#include <linux/videodev2.h>
+#include <linux/workqueue.h>
+
+#include <media/cec.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-dv-timings.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fwnode.h>
+#include <uapi/linux/it6625.h>
+
+static int debug = 3;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "debug level (0-3)");
+
+#define REG_CHIP_ID_0 0x00
+#define REG_CHIP_ID_1 0x01
+#define REG_FW_VER_MAJOR 0x03
+#define REG_FW_VER_MINOR 0x04
+#define REG_PROTOCOL_VERSION 0x05
+#define B_PVER_MINOR  BIT(0)
+#define B_PVER_MAJOR  BIT(4)
+
+#define REG_CMD_SET 0x10
+#define CMD_SET_CEC_LA 0xC0
+#define CMD_SET_CEC_ENABLE 0xC1
+
+#define REG_EDID_START 0x20
+#define REG_CEC_RX_DATA 0x20
+#define REG_CEC_TX_DATA 0x30
+
+#define REG_H_ACTIVE_1 0x50
+#define REG_H_ACTIVE_0 0x51
+#define REG_V_ACTIVE_1 0x52
+#define REG_V_ACTIVE_0 0x53
+#define REG_H_TOTAL_1 0x54
+#define REG_H_TOTAL_0 0x55
+#define REG_V_TOTAL_1 0x56
+#define REG_V_TOTAL_0 0x57
+#define REG_VID_PCLK 0x58
+#define REG_H_FP_1 0x5C
+#define REG_H_FP_0 0x5D
+#define REG_H_SW_1 0x5E
+#define REG_H_SW_0 0x5F
+#define REG_H_BP_1 0x60
+#define REG_H_BP_0 0x61
+#define REG_V_FP_1 0x62
+#define REG_V_FP_0 0x63
+#define REG_V_SW_1 0x64
+#define REG_V_SW_0 0x65
+#define REG_V_BP_1 0x66
+#define REG_V_BP_0 0x67
+#define REG_VID_INFO 0x68
+#define B_INTERLACE  BIT(0)
+#define B_HSWPOL  BIT(1)
+#define B_VSWPOL  BIT(2)
+#define B_PIXEL_REP  BIT(4)
+
+#define REG_VIC 0x69
+#define REG_HDMI_VIDEO_INFO 0x6A
+#define B_COLOR_MODE  BIT(0)
+#define B_COLOR_DEPTH  BIT(4)
+#define REG_HDMI_AUDIO_INFO1 0x6B
+#define B_AUD_FS  BIT(0)
+
+#define REG_HDMI_AUDIO_INFO2 0x6C
+#define B_AUD_CH  BIT(0)
+#define B_AUD_WL  BIT(4)
+
+#define REG_HDMI_AUDIO_INFO3 0x6D
+#define B_AUD_TYPE  BIT(0)
+#define B_AUD_MS  BIT(2)
+#define B_AUD_3D  BIT(3)
+
+#define REG_AUDIO_FMT 0x6E
+#define B_I2S_WL  BIT(0)
+#define B_I2S_ALN BIT(2)
+#define B_I2S_DLY BIT(3)
+#define B_I2S_LR  BIT(4)
+#define B_I2S_SFT BIT(5)
+#define B_AUD_OUT_IF  BIT(6)
+
+#define REG_IF_LATCH_HB 0x6F
+#define REG_IF_DATA 0x70
+#define REG_EMP_DATA 0xA0
+#define REG_AVI_DATA 0xAE
+
+#define REG_TX_STATUS 0xE0
+
+#define REG_RX_STATUS 0xE2
+#define B_RX_5V BIT(0)
+#define B_RX_HPD BIT(1)
+#define B_RX_STABLE BIT(2)
+#define B_RX_HDMI BIT(3)
+#define B_RX_AVMUTE BIT(4)
+#define B_RX_AUD_ON BIT(5)
+
+#define REG_RX_HDCP_STS 0xE3
+#define B_HDCP1_AUTH_START BIT(0)
+#define B_HDCP2_AUTH_START BIT(1)
+#define B_HDCP_AUTH_DONE BIT(2)
+#define B_HDCP_ENC BIT(3)
+
+#define REG_CEC_STATUS 0xE4
+#define B_CEC_TX_DONE BIT(0)
+#define B_CEC_TX_NACK BIT(1)
+
+#define REG_CEC_RX_DATA_LEN 0xE5
+#define REG_CEC_TX_DATA_LEN 0xE6
+
+#define REG_SYS_MIPI_INT 0xEB
+#define B_MIPI_OUTPUT_ENABLE BIT(0)
+#define B_MIPI_VIDEO_UNSTABLE BIT(1)
+
+#define REG_RX_INT_STATUS1 0xEC
+#define B_HDMI_5V_CHG   BIT(0)
+#define B_HDMI_VID_CHG  BIT(1)
+#define B_HDMI_AUD_CHG  BIT(2)
+#define B_HDMI_CP_CHG   BIT(3)
+#define B_HDMI_IF_LATCH BIT(4)
+#define B_HDMI_NO_IF_LATCH  BIT(5)
+#define B_HDMI_EMP      BIT(6)
+#define B_HDMI_NO_EMP   BIT(7)
+
+#define REG_RX_INT_STATUS2 0xED
+#define B_HDMI_AVI      BIT(0)
+#define B_HDMI_NO_AVI   BIT(1)
+#define B_HDMI_VSIF     BIT(2)
+#define B_HDMI_NO_VSIF  BIT(3)
+#define B_HDMI_AVMUTE_CHG  BIT(4)
+
+#define REG_CHIP_CONTROL 0xF0
+#define B_HDMI_RESET  BIT(5)
+#define B_FW_START  BIT(6)
+
+#define REG_MIPI_CFG 0xF1
+#define M_MIPI_LANE  0x03
+#define B_MIPI_SPLIT  BIT(2)
+#define B_MIPI_SPLIT_CFG  BIT(3)
+#define B_MIPI_DPHY  BIT(4)
+#define B_MIPI_USE_DSI  BIT(5)
+#define B_MIPI_CONTINU_CLK  BIT(6)
+
+#define REG_MIPI_DATA_TYPE 0xF2
+#define CSI_RGB444          0x20
+#define CSI_RGB555          0x21
+#define CSI_RGB565          0x22
+#define CSI_RGB666          0x23
+#define CSI_RGB888          0x24
+#define CSI_YUV420_8b_L     0x1A
+#define CSI_YUV420_8b       0x1C
+#define CSI_YUV420_10b      0x1D
+#define CSI_YUV422_8b       0x1E
+#define CSI_YUV422_10b      0x1F
+#define CSI_RGB_10b         0x30
+#define CSI_RGB_12b         0x31
+#define CSI_YUV422_12b      0x32
+#define CSI_YUV420_10b_L    0x33
+#define CSI_YUV420_12b      0x34
+#define CSI_YUV444_8b       0x35
+#define CSI_YUV444_10b      0x36
+#define CSI_YUV444_12b      0x37
+
+#define REG_MIPI_CONTROL 0xF3
+#define B_MIPI_OUTPUT    BIT(0)
+
+#define REG_RX_CFG 0xF4
+#define B_MANUAL_HPD    BIT(0)
+#define B_HPD_HIGH    BIT(1)
+#define B_HPD_TOGGLE    BIT(3)
+
+#define REG_CSC_CFG 0xF5
+#define B_DYNAMIC_RANGE BIT(0)
+
+#define REG_MISC_CFG 0xF6
+#define B_BAUD_RATE BIT(0)
+#define B_DEBUG_MSG BIT(1)
+
+#define REG_HPD_DELAY 0xF7
+#define B_DELAY_COUNT BIT(0)
+#define B_DELAY_UNIT BIT(7)
+
+#define REG_INFO_BANK_SEL 0xFD
+#define CTL_BANK_EDID_READ 1
+#define CTL_BANK_EDID_WRITE 5
+
+#define REG_HOST_CTRL_INT 0xFE
+#define B_CMD_SET BIT(4)
+#define B_CEC_SEND_DATA BIT(5)
+#define B_CONFIG_UPDATE BIT(6)
+#define B_IF_BANK BIT(7)
+
+#define REG_MCU_INTERRUPT 0xFF
+#define B_SYS_INT_ACTIVE BIT(0)
+#define B_CEC_RX_RECEIVED BIT(1)
+#define B_CEC_TX_UPDATE BIT(2)
+
+#define EDID_NUM_BLOCKS_MAX 4
+#define EDID_BLOCK_SIZE 128
+
+#define I2C_MAX_XFER_SIZE  8
+#define POLL_INTERVAL_CEC_MS	10
+#define POLL_INTERVAL_MS	40
+
+#define AUD32K   0x03
+#define AUD44K   0x00
+#define AUD48K   0x02
+#define AUD64K   0x0B
+#define AUD88K   0x08
+#define AUD96K   0x0A
+#define AUD128K  0x2B
+#define AUD176K  0x0C
+#define AUD192K  0x0E
+#define AUD256K  0x1B
+#define AUD352K  0x0D
+#define AUD384K  0x05
+#define AUD512K  0x3B
+#define AUD705K  0x2D
+#define AUD768K  0x09
+#define AUD1024K 0x35
+#define AUD1411K 0x1D
+#define AUD1536K 0x15
+
+enum it6625_chip_type {
+	IT6625_CHIP = 0,
+	IT6626_CHIP = 1,
+};
+
+struct it6625 {
+	struct device *dev;
+	struct i2c_client *i2c_client;
+	struct regmap *it6625_regmap;
+	enum it6625_chip_type chip_type;
+
+	/* protects concurrent access to the chip's registers and state */
+	struct mutex it6625_lock;
+	/* serializes the complete VIDIOC_S_EDID sequence against itself */
+	struct mutex edid_lock;
+	/* serializes a full InfoFrame debugfs read transaction against itself */
+	struct mutex if_read_lock;
+	/*
+	 * protects if_active/if_type/if_snapshot/if_snapshot_err/
+	 * if_snapshot_done and the REG_MCU_INTERRUPT/REG_RX_INT_STATUS1/2/
+	 * REG_IF_LATCH_HB/REG_IF_DATA register group between the interrupt
+	 * path and the InfoFrame debugfs callback. Never held across
+	 * wait_for_completion_timeout(). Nests outside it6625_lock.
+	 */
+	struct mutex if_state_lock;
+
+	struct v4l2_subdev sd;
+	struct v4l2_mbus_config_mipi_csi2 bus;
+	struct video_device *vdev;
+	struct media_pad pad;
+	struct v4l2_ctrl_handler hdl;
+
+	/* controls */
+	struct v4l2_ctrl *ctrl_5v_detect;
+	struct v4l2_ctrl *ctrl_audio_sampling_rate;
+	struct v4l2_ctrl *ctrl_audio_present;
+	struct v4l2_ctrl *ctrl_link_freq;
+
+	struct delayed_work hpd_delayed_work;
+
+	struct timer_list timer;
+	struct work_struct polling_work;
+
+	struct v4l2_dv_timings timings;
+
+	u8 csi_lanes;
+	u8 port_num;
+	enum v4l2_mbus_type bus_type;
+	u8 csi_format;
+	u32 mbus_fmt_code;
+	/* number of EDID blocks currently loaded, protected by edid_lock */
+	u8 edid_blocks;
+
+	struct gpio_desc *reset_gpio;
+
+	struct cec_adapter *cec_adap;
+
+	struct dentry *debugfs_dir;
+
+	struct v4l2_debugfs_if *infoframes;
+	struct completion if_latched;
+	/* true while an InfoFrame debugfs request is outstanding */
+	bool if_active;
+	/* HDMI packet-type byte currently armed in REG_IF_LATCH_HB */
+	u32 if_type;
+	/* driver-private copy of REG_IF_DATA, captured at the genuine latch */
+	u8 if_snapshot[31];
+	/* it6625_read_bytes() result for the if_snapshot capture */
+	int if_snapshot_err;
+	/* set just before complete(), to disambiguate timeout vs. capture */
+	bool if_snapshot_done;
+};
+
+/*
+ * Index 0: D-PHY (4-lane). Index 1: C-PHY (3-trio) -- the confirmed
+ * hardware max C-PHY capability, tested single-port/three-trio.
+ */
+static const s64 it6625_link_freq[] = {
+	445500000,
+	2500000000LL,
+};
+
+/*
+ * Shared cap for every topology except the reference exception below:
+ * IT6625 (no C-PHY support at all), IT6626 running D-PHY, and IT6626
+ * running C-PHY with fewer than three trios. This is conservative
+ * scoping, not a claim that one-/two-trio C-PHY can't also support a
+ * higher rate -- they're simply unvalidated.
+ */
+static const struct v4l2_dv_timings_cap it6625_timings_cap = {
+	.type = V4L2_DV_BT_656_1120,
+	/* keep this initialization for compatibility with GCC < 4.4.6 */
+	.reserved = { 0 },
+
+	V4L2_INIT_BT_TIMINGS(640, 3840, 480, 2160, 27000000, 300000000,
+			     V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
+			     V4L2_DV_BT_STD_GTF | V4L2_DV_BT_STD_CVT,
+			     V4L2_DV_BT_CAP_PROGRESSIVE | V4L2_DV_BT_CAP_INTERLACED |
+			     V4L2_DV_BT_CAP_REDUCED_BLANKING | V4L2_DV_BT_CAP_CUSTOM)
+};
+
+/*
+ * IT6626 C-PHY, three trios: raised pixel-clock ceiling (594 MHz vs
+ * the shared 300 MHz cap) for this topology's higher C-PHY capability.
+ */
+static const struct v4l2_dv_timings_cap it6626_cphy_3trio_timings_cap = {
+	.type = V4L2_DV_BT_656_1120,
+	.reserved = { 0 },
+
+	V4L2_INIT_BT_TIMINGS(640, 3840, 480, 2160, 27000000, 594000000,
+			     V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
+			     V4L2_DV_BT_STD_GTF | V4L2_DV_BT_STD_CVT,
+			     V4L2_DV_BT_CAP_PROGRESSIVE | V4L2_DV_BT_CAP_INTERLACED |
+			     V4L2_DV_BT_CAP_REDUCED_BLANKING | V4L2_DV_BT_CAP_CUSTOM)
+};
+
+static const struct v4l2_dv_timings_cap *
+it6625_get_timings_cap(struct it6625 *it6625)
+{
+	if (it6625->chip_type == IT6626_CHIP &&
+	    it6625->bus_type == V4L2_MBUS_CSI2_CPHY &&
+	    it6625->csi_lanes == 3)
+		return &it6626_cphy_3trio_timings_cap;
+
+	return &it6625_timings_cap;
+}
+
+static const struct it6625_format_info {
+	u8 csi_format;
+	u32 mbus_fmt_code;
+} it6625_formats[] = {
+	{ CSI_YUV422_8b, MEDIA_BUS_FMT_UYVY8_1X16 },
+	{ CSI_RGB888, MEDIA_BUS_FMT_RGB888_1X24 },
+	{ CSI_YUV444_8b, MEDIA_BUS_FMT_YUV8_1X24 },
+};
+
+static inline int it6625_csi_format_idx(u8 csi_format)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(it6625_formats); i++) {
+		if (it6625_formats[i].csi_format == csi_format)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static inline int it6625_csi_mbus_code_idx(u32 mbus_fmt_code)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(it6625_formats); i++) {
+		if (it6625_formats[i].mbus_fmt_code == mbus_fmt_code)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static inline struct it6625 *sd_to_6625(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct it6625, sd);
+}
+
+static const struct regmap_config it6625_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.cache_type = REGCACHE_NONE,
+	.max_raw_read = I2C_MAX_XFER_SIZE,
+	.max_raw_write = I2C_MAX_XFER_SIZE,
+};
+
+static int it6625_regmap_i2c_init(struct i2c_client *client,
+				  struct it6625 *it6625)
+{
+	it6625->i2c_client = client;
+	it6625->dev = &client->dev;
+
+	it6625->it6625_regmap = devm_regmap_init_i2c(it6625->i2c_client,
+						     &it6625_regmap_config);
+	if (IS_ERR(it6625->it6625_regmap))
+		return PTR_ERR(it6625->it6625_regmap);
+
+	return 0;
+}
+
+static int it6625_read_byte(struct it6625 *it6625, u8 reg)
+{
+	unsigned int val;
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_read(it6625->it6625_regmap, reg, &val);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] read failed err: %d", reg, err);
+		return err;
+	}
+
+	return val;
+}
+
+static int it6625_write_byte(struct it6625 *it6625, u8 reg, u8 val)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_write(it6625->it6625_regmap, reg, val);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] write failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_set_bits(struct it6625 *it6625, u8 reg, u8 mask, u8 val)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_update_bits(it6625->it6625_regmap, reg, mask, val);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] set bits failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_read_bytes(struct it6625 *it6625, u8 reg, u8 *buf, int len)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_bulk_read(it6625->it6625_regmap, reg, buf, len);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] read failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_write_bytes(struct it6625 *it6625, u8 reg, u8 *buf, int len)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_bulk_write(it6625->it6625_regmap, reg, buf, len);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] write failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_wait_for_status(struct it6625 *it6625, u8 reg, u8 val,
+				  int timeout_ms)
+{
+	struct device *dev = it6625->dev;
+	int status;
+	int rval;
+	int sleep_ms = 10;
+	int timeout_round_ms = DIV_ROUND_UP(timeout_ms, sleep_ms) * sleep_ms;
+
+	status = read_poll_timeout(it6625_read_byte, rval, rval == val,
+				   sleep_ms * 1000,
+				   timeout_round_ms * 1000,
+				   false, it6625, reg);
+
+	dev_info(dev, "%s status = %d %d", __func__, status, (int)rval);
+	if (status < 0) {
+		dev_err(dev, "%s err status = %d", __func__, status);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void it6625_write_command(struct it6625 *it6625, u8 *cmds, int cmd_len)
+{
+	it6625_write_bytes(it6625, REG_CMD_SET, cmds, cmd_len);
+	it6625_write_byte(it6625, REG_HOST_CTRL_INT, B_CMD_SET);
+	it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static int it6625_update_config(struct it6625 *it6625)
+{
+	int err;
+
+	err = it6625_set_bits(it6625, REG_HOST_CTRL_INT,
+			      B_CONFIG_UPDATE, B_CONFIG_UPDATE);
+	if (err < 0)
+		return err;
+
+	return it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static int it6625_set_bank(struct it6625 *it6625, u8 bank)
+{
+	int err;
+
+	err = it6625_write_byte(it6625, REG_INFO_BANK_SEL, bank);
+	if (err < 0)
+		return err;
+
+	err = it6625_write_byte(it6625, REG_HOST_CTRL_INT, B_IF_BANK);
+	if (err < 0)
+		return err;
+
+	return it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static inline bool is_hdmi(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? false : (val & B_RX_HDMI);
+}
+
+static inline bool hdmi_5v_power_present(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? false : (val & B_RX_5V);
+}
+
+static inline bool no_signal(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? true : !(val & B_RX_STABLE);
+}
+
+static inline bool audio_present(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? false : (val & B_RX_AUD_ON);
+}
+
+static int get_audio_sampling_rate(struct it6625 *it6625)
+{
+	int fs_id;
+	int i, freq = 0;
+	const struct fs_id_map {
+		u8 fs_id;
+		u32 freq;
+	} s_fsid_map[] = {
+		{ AUD32K,    32000 },
+		{ AUD44K,    44100 },
+		{ AUD48K,    48000 },
+		{ AUD64K,    64000 },
+		{ AUD88K,    88200 },
+		{ AUD96K,    96000 },
+
+		{ AUD128K,  128000 },
+		{ AUD176K,  176400 },
+		{ AUD192K,  192000 },
+		{ AUD256K,  256000 },
+		{ AUD352K,  352800 },
+		{ AUD384K,  384000 },
+
+		{ AUD512K,  512000 },
+		{ AUD705K,  705600 },
+		{ AUD768K,  768000 },
+		{ AUD1024K, 1024000 },
+		{ AUD1411K, 1411200 },
+		{ AUD1536K, 1536000 },
+	};
+
+	if (no_signal(it6625) || !audio_present(it6625))
+		return 0;
+
+	guard(mutex)(&it6625->it6625_lock);
+
+	fs_id = it6625_read_byte(it6625, REG_HDMI_AUDIO_INFO1);
+	if (fs_id < 0)
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(s_fsid_map); i++) {
+		if (s_fsid_map[i].fs_id == fs_id) {
+			freq = s_fsid_map[i].freq;
+			break;
+		}
+	}
+
+	return freq;
+}
+
+static u64 it6625_get_pclk(struct it6625 *it6625)
+{
+	u32 pclk;
+	u8 ck[4];
+	int ret;
+
+	ret = it6625_read_bytes(it6625, REG_VID_PCLK, ck, 4);
+	if (ret < 0) {
+		dev_err(it6625->dev, "failed to read pixel clock");
+		return 0;
+	}
+
+	pclk = ck[0];
+	pclk <<= 8;
+	pclk |= ck[1];
+	pclk <<= 8;
+	pclk |= ck[2];
+	pclk <<= 8;
+	pclk |= ck[3];
+
+	v4l2_dbg(1, debug, &it6625->sd, "%s: pclk=%u (%08x)",
+		 __func__, pclk, pclk);
+
+	return (u64)pclk * 1000;
+}
+
+static int it6625_read_edid(struct it6625 *it6625, u8 *edid, int start_block,
+			    int num_blocks)
+{
+	int i, bank_ctrl, err = 0;
+	struct device *dev = it6625->dev;
+
+	if (!edid) {
+		dev_err(dev, "edid buffer is NULL");
+		return -EINVAL;
+	}
+
+	if (start_block < 0 || num_blocks <= 0 ||
+	    start_block > EDID_NUM_BLOCKS_MAX ||
+	    num_blocks > EDID_NUM_BLOCKS_MAX ||
+	    start_block + num_blocks > EDID_NUM_BLOCKS_MAX) {
+		dev_err(dev,
+			"invalid block range: start_block=%d, num_blocks=%d",
+			start_block, num_blocks);
+		return -EINVAL;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+	for (i = 0; i < num_blocks; i++) {
+		bank_ctrl = CTL_BANK_EDID_READ + start_block + i;
+		err = it6625_set_bank(it6625, bank_ctrl);
+		if (err < 0)
+			break;
+
+		err = it6625_read_bytes(it6625, REG_EDID_START,
+					edid + (i * 128), 128);
+		if (err < 0)
+			break;
+	}
+
+	it6625_set_bank(it6625, 0);
+
+	return err < 0 ? err : num_blocks;
+}
+
+static int it6625_write_edid(struct it6625 *it6625, u8 *edid, int start_block,
+			     int num_blocks)
+{
+	int i, bank_ctrl, err = 0;
+	struct device *dev = it6625->dev;
+
+	if (start_block < 0 || num_blocks <= 0 ||
+	    start_block > EDID_NUM_BLOCKS_MAX ||
+	    num_blocks > EDID_NUM_BLOCKS_MAX ||
+	    start_block + num_blocks > EDID_NUM_BLOCKS_MAX) {
+		dev_err(dev,
+			"invalid block range: start_block=%d, num_blocks=%d",
+			start_block, num_blocks);
+		return -EINVAL;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+	for (i = 0; i < num_blocks; i++) {
+		bank_ctrl = CTL_BANK_EDID_WRITE + start_block + i;
+		err = it6625_set_bank(it6625, bank_ctrl);
+		if (err < 0)
+			break;
+
+		err = it6625_write_bytes(it6625, REG_EDID_START,
+					 edid + (i * 128), 128);
+		if (err < 0)
+			break;
+
+		err = it6625_update_config(it6625);
+		if (err < 0)
+			break;
+	}
+
+	it6625_set_bank(it6625, 0);
+
+	return err < 0 ? err : num_blocks;
+}
+
+static void it6625_enable_auto_hpd(struct it6625 *it6625)
+{
+	dev_dbg(it6625->dev, "%s: auto HPD", __func__);
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_RX_CFG, 0x03, 0x00);
+	it6625_update_config(it6625);
+}
+
+static void it6625_disable_hpd(struct it6625 *it6625)
+{
+	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_RX_CFG, 0x03, 0x01);
+	it6625_update_config(it6625);
+}
+
+static void it6625_enable_hpd(struct it6625 *it6625)
+{
+	schedule_delayed_work(&it6625->hpd_delayed_work, HZ / 7);
+}
+
+static void it6625_hpd_delayed_work(struct work_struct *work)
+{
+	struct it6625 *it6625 = container_of(work,
+			struct it6625, hpd_delayed_work.work);
+	int val = 0;
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_RX_CFG, 0x03, val);
+	it6625_update_config(it6625);
+}
+
+static int it6625_get_detected_timings(struct it6625 *it6625,
+				       struct v4l2_dv_timings *timings)
+{
+	struct v4l2_bt_timings *bt = &timings->bt;
+	int val;
+	unsigned int width, height;
+	u8 buffer[4];
+	u8 buffer2[12];
+
+	if (no_signal(it6625)) {
+		dev_err(it6625->dev, "no signal detected");
+		return -ENOLINK;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+
+	memset(timings, 0, sizeof(struct v4l2_dv_timings));
+	timings->type = V4L2_DV_BT_656_1120;
+	val = it6625_read_byte(it6625, REG_VID_INFO);
+	if (val < 0) {
+		dev_err(it6625->dev, "failed to read video info");
+		return -EIO;
+	}
+
+	bt->interlaced = val & B_INTERLACE ?
+			 V4L2_DV_INTERLACED : V4L2_DV_PROGRESSIVE;
+
+	if (it6625_read_bytes(it6625, REG_H_ACTIVE_1, buffer, 4) < 0)
+		return -EIO;
+
+	width = ((buffer[0] & 0xff) << 8) + buffer[1];
+	height = ((buffer[2] & 0xff) << 8) + buffer[3];
+
+	bt->width = width;
+	bt->height = height;
+
+	if (it6625_read_bytes(it6625, REG_H_FP_1, buffer2, 12) < 0)
+		return -EIO;
+
+	bt->hfrontporch = ((buffer2[0] & 0xff) << 8) + buffer2[1];
+	bt->hsync = ((buffer2[2] & 0xff) << 8) + buffer2[3];
+	bt->hbackporch = ((buffer2[4] & 0xff) << 8) + buffer2[5];
+	bt->vfrontporch = ((buffer2[6] & 0xff) << 8) + buffer2[7];
+	bt->vsync = ((buffer2[8] & 0xff) << 8) + buffer2[9];
+	bt->vbackporch = ((buffer2[10] & 0xff) << 8) + buffer2[11];
+
+	bt->pixelclock = it6625_get_pclk(it6625);
+	if (bt->interlaced == V4L2_DV_INTERLACED) {
+		bt->height *= 2;
+		bt->il_vsync = bt->vsync + 1;
+	}
+
+	return 0;
+}
+
+static void it6625_show_avi_infoframe(struct it6625 *it6625)
+{
+	struct device *dev = it6625->dev;
+	union hdmi_infoframe frame;
+	u8 buffer[HDMI_INFOFRAME_SIZE(AVI)];
+	u8 ver, len;
+	int ret;
+
+	if (!is_hdmi(it6625)) {
+		dev_err(dev, "not HDMI signal, skip AVI infoframe log");
+		return;
+	}
+
+	ret = it6625_read_bytes(it6625, REG_AVI_DATA, buffer + 1,
+				HDMI_INFOFRAME_SIZE(AVI) - 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to read AVI infoframe data");
+		return;
+	}
+
+	len = buffer[1];
+	ver = buffer[2];
+
+	buffer[0] = HDMI_INFOFRAME_TYPE_AVI;
+	buffer[1] = ver;
+	buffer[2] = len;
+
+	ret = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer));
+	if (ret < 0) {
+		dev_err(dev, "unpack of AVI infoframe failed");
+		return;
+	}
+
+	hdmi_infoframe_log(KERN_INFO, dev, &frame);
+}
+
+static int it6625_s_ctrl_detect_hdmi_5v(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	return v4l2_ctrl_s_ctrl(it6625->ctrl_5v_detect,
+				hdmi_5v_power_present(it6625));
+}
+
+static int it6625_s_ctrl_audio_sampling_rate(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	return v4l2_ctrl_s_ctrl(it6625->ctrl_audio_sampling_rate,
+				get_audio_sampling_rate(it6625));
+}
+
+static int it6625_s_ctrl_audio_present(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	return v4l2_ctrl_s_ctrl(it6625->ctrl_audio_present,
+				audio_present(it6625));
+}
+
+static void it6625_v4l2_sd_ctrl_update(struct v4l2_subdev *sd)
+{
+	it6625_s_ctrl_detect_hdmi_5v(sd);
+	it6625_s_ctrl_audio_sampling_rate(sd);
+	it6625_s_ctrl_audio_present(sd);
+}
+
+static void it6625_enable_stream_locked(struct it6625 *it6625, bool enable)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int val;
+
+	lockdep_assert_held(&it6625->it6625_lock);
+
+	v4l2_dbg(3, debug, sd, "%s: %sable",
+		 __func__, enable ? "en" : "dis");
+
+	val = enable ? B_MIPI_OUTPUT : 0;
+	it6625_set_bits(it6625, REG_MIPI_CONTROL, B_MIPI_OUTPUT, val);
+	it6625_update_config(it6625);
+}
+
+static void it6625_enable_stream(struct it6625 *it6625, bool enable)
+{
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_enable_stream_locked(it6625, enable);
+}
+
+static void it6625_set_mipi_config_locked(struct it6625 *it6625, u32 cfg_val)
+{
+	u8 mipi_data_type;
+
+	lockdep_assert_held(&it6625->it6625_lock);
+
+	dev_dbg(it6625->dev, "mipi_data_type = 0x%x", cfg_val);
+
+	mipi_data_type = cfg_val & 0xFF;
+	it6625_write_byte(it6625, REG_MIPI_DATA_TYPE, mipi_data_type);
+	it6625_update_config(it6625);
+}
+
+static inline unsigned int fps_from_bt_timings(const struct v4l2_bt_timings *t)
+{
+	if (!V4L2_DV_BT_FRAME_HEIGHT(t) || !V4L2_DV_BT_FRAME_WIDTH(t))
+		return 0;
+
+	return DIV_ROUND_CLOSEST((unsigned int)t->pixelclock,
+				 V4L2_DV_BT_FRAME_HEIGHT(t) *
+				 V4L2_DV_BT_FRAME_WIDTH(t));
+}
+
+static void it6625_initial_setup(struct it6625 *it6625)
+{
+	int val = 0;
+
+	guard(mutex)(&it6625->it6625_lock);
+
+	/*
+	 * REG_MIPI_CFG[0:2] lane count field: 1 lane -> 0, 2 lanes -> 1,
+	 * 3 lanes (C-PHY only) -> 3, 4 lanes (D-PHY only) -> 3.
+	 */
+	switch (it6625->csi_lanes) {
+	case 1:
+		val = FIELD_PREP(M_MIPI_LANE, 0);
+		break;
+	case 2:
+		val = FIELD_PREP(M_MIPI_LANE, 1);
+		break;
+	default:
+		val = FIELD_PREP(M_MIPI_LANE, 3);
+		break;
+	}
+
+	if (it6625->bus_type == V4L2_MBUS_CSI2_DPHY)
+		val |= FIELD_PREP(B_MIPI_DPHY, 1);
+
+	if (it6625->port_num == 2)
+		val |= FIELD_PREP(B_MIPI_SPLIT, 1);
+
+	it6625_write_byte(it6625, REG_MIPI_CFG, val);
+	it6625_write_byte(it6625, REG_MIPI_DATA_TYPE, it6625->csi_format);
+	it6625_write_byte(it6625, REG_MIPI_CONTROL, 0x00);
+	it6625_write_byte(it6625, REG_RX_CFG, 0x00);
+
+	it6625_set_bits(it6625, REG_HOST_CTRL_INT, B_CONFIG_UPDATE, B_CONFIG_UPDATE);
+	it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static int it6625_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct it6625 *it6625 = adap->priv;
+	u8 cmds[2];
+
+	cmds[0] = CMD_SET_CEC_ENABLE;
+	cmds[1] = enable ? 1 : 0;
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_command(it6625, cmds, sizeof(cmds));
+
+	return 0;
+}
+
+static void it6625_cec_reset_la(struct it6625 *it6625, bool keep_enabled)
+{
+	u8 cmds[2];
+
+	if (keep_enabled) {
+		cmds[0] = CMD_SET_CEC_LA;
+		cmds[1] = CEC_LOG_ADDR_UNREGISTERED;
+	} else {
+		cmds[0] = CMD_SET_CEC_ENABLE;
+		cmds[1] = 0;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_command(it6625, cmds, sizeof(cmds));
+}
+
+static int it6625_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
+{
+	struct it6625 *it6625 = adap->priv;
+	u8 cmds[2] = {CMD_SET_CEC_LA, log_addr};
+
+	dev_dbg(it6625->dev, "%s: la=%d", __func__, log_addr);
+
+	if (log_addr == CEC_LOG_ADDR_INVALID) {
+		it6625_cec_reset_la(it6625, adap->is_enabled);
+		return 0;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_command(it6625, cmds, sizeof(cmds));
+
+	return 0;
+}
+
+static int it6625_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				    u32 signal_free_time, struct cec_msg *msg)
+{
+	struct it6625 *it6625 = adap->priv;
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_bytes(it6625, REG_CEC_TX_DATA, msg->msg, msg->len);
+	it6625_write_byte(it6625, REG_CEC_TX_DATA_LEN, msg->len);
+	it6625_set_bits(it6625, REG_HOST_CTRL_INT, B_CEC_SEND_DATA, B_CEC_SEND_DATA);
+	it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+
+	return 0;
+}
+
+static const struct cec_adap_ops it6625_cec_adap_ops = {
+	.adap_enable = it6625_cec_adap_enable,
+	.adap_log_addr = it6625_cec_adap_log_addr,
+	.adap_transmit = it6625_cec_adap_transmit,
+};
+
+static void it6625_cec_handler(struct it6625 *it6625, u8 intstatus)
+{
+	struct cec_msg rxmsg = {};
+	int val = 0;
+
+	if (intstatus & B_CEC_RX_RECEIVED) {
+		scoped_guard(mutex, &it6625->it6625_lock) {
+			val = it6625_read_byte(it6625, REG_CEC_RX_DATA_LEN);
+			if (val > 0 && val <= CEC_MAX_MSG_SIZE)
+				it6625_read_bytes(it6625, REG_CEC_RX_DATA, &rxmsg.msg[0], val);
+			it6625_write_byte(it6625, REG_CEC_RX_DATA_LEN, 0);
+		}
+
+		if (val > 0 && val <= CEC_MAX_MSG_SIZE) {
+			rxmsg.len = val;
+			cec_received_msg(it6625->cec_adap, &rxmsg);
+		} else {
+			dev_err(it6625->dev, "invalid CEC RX length %d", val);
+		}
+	}
+
+	if (intstatus & B_CEC_TX_UPDATE) {
+		val = it6625_read_byte(it6625, REG_CEC_STATUS);
+		if (val < 0) {
+			dev_err(it6625->dev, "read CEC status failed");
+			return;
+		}
+
+		if (val & BIT(0)) {
+			cec_transmit_attempt_done(it6625->cec_adap,
+						  CEC_TX_STATUS_OK);
+		} else if (val & BIT(1)) {
+			cec_transmit_attempt_done(it6625->cec_adap,
+						  CEC_TX_STATUS_NACK);
+		} else {
+			dev_info(it6625->dev, "unknown CEC status %02X", val);
+			cec_transmit_attempt_done(it6625->cec_adap,
+						  CEC_TX_STATUS_NACK);
+		}
+	}
+}
+
+static void it6625_irq_format_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	struct v4l2_dv_timings timings;
+	const struct v4l2_event it6625_ev_fmt = {
+		.type = V4L2_EVENT_SOURCE_CHANGE,
+		.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
+	};
+	int ret;
+
+	if (no_signal(it6625)) {
+		if (sd->devnode)
+			v4l2_subdev_notify_event(sd, &it6625_ev_fmt);
+		return;
+	}
+
+	ret = it6625_get_detected_timings(it6625, &timings);
+	if (ret < 0) {
+		v4l2_dbg(1, debug, sd, "Failed to get detected timings");
+		return;
+	}
+
+	if (sd->devnode)
+		v4l2_subdev_notify_event(sd, &it6625_ev_fmt);
+}
+
+static void it6625_irq_hdmi_audio_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	it6625_s_ctrl_audio_sampling_rate(sd);
+	it6625_s_ctrl_audio_present(sd);
+}
+
+static void it6625_get_timings(struct it6625 *it6625,
+			       struct v4l2_dv_timings *timings)
+{
+	guard(mutex)(&it6625->it6625_lock);
+	*timings = it6625->timings;
+}
+
+static void it6625_clear_timings(struct it6625 *it6625)
+{
+	guard(mutex)(&it6625->it6625_lock);
+	memset(&it6625->timings, 0, sizeof(it6625->timings));
+}
+
+static void it6625_irq_hdmi_5v_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	it6625_clear_timings(it6625);
+	it6625_v4l2_sd_ctrl_update(sd);
+}
+
+static void it6625_irq_hdcp_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	u8 cp_sts;
+
+	cp_sts = it6625_read_byte(it6625, REG_RX_HDCP_STS);
+	v4l2_info(sd, "HDCP change to %02X", cp_sts);
+}
+
+static void it6625_irq_infoframe_latch(struct it6625 *it6625)
+{
+	if (!it6625->if_active)
+		return;
+
+	it6625->if_active = false;
+
+	scoped_guard(mutex, &it6625->it6625_lock) {
+		it6625->if_snapshot_err =
+			it6625_read_bytes(it6625, REG_IF_DATA,
+					  it6625->if_snapshot, 31);
+	}
+	it6625->if_snapshot_done = true;
+	complete(&it6625->if_latched);
+}
+
+static void it6625_irq_emata_packet_latch(struct it6625 *it6625)
+{
+	u8 extend_packet[14];
+
+	it6625_read_bytes(it6625, REG_EMP_DATA, extend_packet, 13);
+}
+
+static void it6625_irq_avmute_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int val;
+	u8 avmute;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	if (val < 0)
+		return;
+
+	avmute = (val & B_RX_AVMUTE) ? 1 : 0;
+	v4l2_info(sd, "AVMute change to %d", avmute);
+}
+
+static void it6625_dispatch_int_status1(struct it6625 *it6625, int int_sts1)
+{
+	if (int_sts1 & B_HDMI_5V_CHG)
+		it6625_irq_hdmi_5v_change(it6625);
+
+	if (int_sts1 & B_HDMI_VID_CHG)
+		it6625_irq_format_change(it6625);
+
+	if (int_sts1 & B_HDMI_AUD_CHG)
+		it6625_irq_hdmi_audio_change(it6625);
+
+	if (int_sts1 & B_HDMI_CP_CHG)
+		it6625_irq_hdcp_change(it6625);
+
+	if (int_sts1 & B_HDMI_IF_LATCH)
+		it6625_irq_infoframe_latch(it6625);
+
+	if (int_sts1 & B_HDMI_EMP)
+		it6625_irq_emata_packet_latch(it6625);
+}
+
+static void it6625_dispatch_int_status2(struct it6625 *it6625, int int_sts2)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	if (int_sts2 & B_HDMI_AVI)
+		it6625_show_avi_infoframe(it6625);
+
+	if (int_sts2 & B_HDMI_NO_AVI)
+		v4l2_info(sd, "AVI-info stopped");
+
+	if (int_sts2 & B_HDMI_AVMUTE_CHG)
+		it6625_irq_avmute_change(it6625);
+}
+
+/* caller must already hold if_state_lock */
+static int it6625_drain_rx_int_status(struct it6625 *it6625)
+{
+	int val1, val2, err;
+
+	val1 = it6625_read_byte(it6625, REG_RX_INT_STATUS1);
+	val2 = it6625_read_byte(it6625, REG_RX_INT_STATUS2);
+
+	err = 0;
+	if (val1 < 0)
+		err = val1;
+	else if (val2 < 0)
+		err = val2;
+
+	if (val1 >= 0) {
+		int werr = it6625_write_byte(it6625, REG_RX_INT_STATUS1, 0x00);
+
+		if (werr && !err)
+			err = werr;
+		it6625_dispatch_int_status1(it6625, val1);
+	}
+
+	if (val2 >= 0) {
+		int werr = it6625_write_byte(it6625, REG_RX_INT_STATUS2, 0x00);
+
+		if (werr && !err)
+			err = werr;
+		it6625_dispatch_int_status2(it6625, val2);
+	}
+
+	return err;
+}
+
+/* caller must already hold if_state_lock */
+static int it6625_drain_interrupts(struct it6625 *it6625, bool *had_event)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int val, err;
+
+	val = it6625_read_byte(it6625, REG_MCU_INTERRUPT);
+	if (val < 0) {
+		if (had_event)
+			*had_event = false;
+		return val;
+	}
+	if (had_event)
+		*had_event = val > 0;
+	if (val == 0)
+		return 0;
+
+	err = it6625_write_byte(it6625, REG_MCU_INTERRUPT, val);
+
+	v4l2_dbg(1, debug, sd, "%s: INT = 0x%02X", __func__, val);
+
+	if (val & (B_CEC_RX_RECEIVED | B_CEC_TX_UPDATE) && it6625->cec_adap)
+		it6625_cec_handler(it6625, val & (B_CEC_RX_RECEIVED | B_CEC_TX_UPDATE));
+
+	if (val & B_SYS_INT_ACTIVE) {
+		int child_err = it6625_drain_rx_int_status(it6625);
+
+		if (child_err && !err)
+			err = child_err;
+	}
+
+	return err;
+}
+
+static bool it6625_interrupt_handler(struct it6625 *it6625)
+{
+	bool had_event = false;
+
+	guard(mutex)(&it6625->if_state_lock);
+	it6625_drain_interrupts(it6625, &had_event);
+	return had_event;
+}
+
+static irqreturn_t it6625_irq_handler(int unused, void *data)
+{
+	struct it6625 *it6625 = data;
+
+	return it6625_interrupt_handler(it6625) ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static void it6625_irq_poll_timer(struct timer_list *t)
+{
+	struct it6625 *it6625 = timer_container_of(it6625, t, timer);
+	unsigned int msecs;
+
+	schedule_work(&it6625->polling_work);
+	/*
+	 * If CEC is present, then we need to poll more frequently,
+	 * otherwise we will miss CEC messages.
+	 */
+	msecs = it6625->cec_adap ? POLL_INTERVAL_CEC_MS : POLL_INTERVAL_MS;
+	mod_timer(&it6625->timer, jiffies + msecs_to_jiffies(msecs));
+}
+
+static void it6625_polling_work(struct work_struct *work)
+{
+	struct it6625 *it6625 = container_of(work, struct it6625,
+					polling_work);
+
+	it6625_interrupt_handler(it6625);
+}
+
+static const char *it6625_csi_format_name(u8 csi_format)
+{
+	switch (csi_format) {
+	case CSI_YUV422_8b:
+		return "YUV422 8bit";
+	case CSI_RGB888:
+		return "RGB888 8bit";
+	case CSI_YUV444_8b:
+		return "YUV444 8bit";
+	default:
+		return "unknown";
+	}
+}
+
+static int it6625_log_status(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	struct v4l2_dv_timings timings, configured_timings;
+	struct v4l2_bt_timings bt;
+	u8 csi_format;
+
+	if (it6625_get_detected_timings(it6625, &timings))
+		v4l2_info(sd, "No video detected");
+	else
+		v4l2_print_dv_timings(sd->name, "Detected format: ", &timings,
+				      true);
+
+	it6625_get_timings(it6625, &configured_timings);
+	v4l2_print_dv_timings(sd->name, "Configured format: ",
+			      &configured_timings, true);
+
+	/* snapshot together so the reported pair was actually configured together */
+	scoped_guard(mutex, &it6625->it6625_lock) {
+		csi_format = it6625->csi_format;
+		bt = it6625->timings.bt;
+	}
+
+	v4l2_info(sd, "CSI format: %s @ %uHz",
+		  it6625_csi_format_name(csi_format),
+		  fps_from_bt_timings(&bt));
+
+	it6625_show_avi_infoframe(it6625);
+
+	return 0;
+}
+
+static int it6625_isr(struct v4l2_subdev *sd, u32 status, bool *handled)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	schedule_work(&it6625->polling_work);
+	*handled = true;
+
+	return 0;
+}
+
+static int it6625_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
+				  struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_SOURCE_CHANGE:
+		return v4l2_src_change_event_subdev_subscribe(sd, fh, sub);
+	case V4L2_EVENT_CTRL:
+		return v4l2_ctrl_subdev_subscribe_event(sd, fh, sub);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int it6625_g_input_status(struct v4l2_subdev *sd, u32 *status)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	bool val;
+
+	val = no_signal(it6625);
+	*status = 0;
+	*status |= val ? V4L2_IN_ST_NO_SIGNAL : 0;
+	*status |= val ? V4L2_IN_ST_NO_SYNC : 0;
+
+	v4l2_dbg(1, debug, sd, "%s: status = 0x%x", __func__, *status);
+
+	return 0;
+}
+
+static int
+it6625_update_timings_if_changed(struct it6625 *it6625,
+				 const struct v4l2_dv_timings *timings)
+{
+	int ret;
+
+	guard(mutex)(&it6625->it6625_lock);
+	if (v4l2_match_dv_timings(&it6625->timings, timings, 0, false)) {
+		ret = 0;
+	} else if (!v4l2_valid_dv_timings(timings, it6625_get_timings_cap(it6625),
+					  NULL, NULL)) {
+		ret = -ERANGE;
+	} else {
+		it6625->timings = *timings;
+		ret = 1;
+	}
+
+	return ret;
+}
+
+static int it6625_enum_dv_timings(struct v4l2_subdev *sd,
+				  struct v4l2_enum_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	if (timings->pad != 0)
+		return -EINVAL;
+
+	return v4l2_enum_dv_timings_cap(timings,
+					it6625_get_timings_cap(it6625), NULL, NULL);
+}
+
+static int it6625_dv_timings_cap(struct v4l2_subdev *sd,
+				 struct v4l2_dv_timings_cap *cap)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	if (cap->pad != 0)
+		return -EINVAL;
+
+	*cap = *it6625_get_timings_cap(it6625);
+
+	return 0;
+}
+
+static int it6625_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	it6625_enable_stream(it6625, enable);
+	return 0;
+}
+
+static int it6625_enum_mbus_code(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *sd_state,
+				 struct v4l2_subdev_mbus_code_enum *code)
+{
+	dev_dbg(sd->dev, "%s: index=%d", __func__, code->index);
+
+	if (code->index >= ARRAY_SIZE(it6625_formats))
+		return -EINVAL;
+
+	dev_dbg(sd->dev, "%s: code=0x%08x", __func__,
+		it6625_formats[code->index].mbus_fmt_code);
+	code->code = it6625_formats[code->index].mbus_fmt_code;
+
+	return 0;
+}
+
+static int it6625_get_mbus_config(struct v4l2_subdev *sd,
+				  unsigned int pad,
+				  struct v4l2_mbus_config *cfg)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	if (pad != 0)
+		return -EINVAL;
+
+	cfg->type = it6625->bus_type;
+	cfg->bus.mipi_csi2.flags = 0;
+	cfg->bus.mipi_csi2.num_data_lanes = it6625->csi_lanes;
+
+	return 0;
+}
+
+static int it6625_pad_s_dv_timings(struct v4l2_subdev *sd, unsigned int pad,
+				   struct v4l2_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int ret;
+
+	if (pad != 0)
+		return -EINVAL;
+
+	if (!timings)
+		return -EINVAL;
+
+	if (debug)
+		v4l2_print_dv_timings(sd->name, __func__, timings, false);
+
+	ret = it6625_update_timings_if_changed(it6625, timings);
+	if (ret == -ERANGE) {
+		v4l2_dbg(1, debug, sd, "%s: timings out of range", __func__);
+		return ret;
+	}
+
+	if (ret == 0)
+		v4l2_dbg(1, debug, sd, "%s: no change", __func__);
+
+	return 0;
+}
+
+static int it6625_pad_g_dv_timings(struct v4l2_subdev *sd, unsigned int pad,
+				   struct v4l2_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	if (pad != 0)
+		return -EINVAL;
+
+	it6625_get_timings(it6625, timings);
+
+	return 0;
+}
+
+static int it6625_pad_query_dv_timings(struct v4l2_subdev *sd,
+				       unsigned int pad,
+				       struct v4l2_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int ret;
+
+	if (pad != 0)
+		return -EINVAL;
+
+	ret = it6625_get_detected_timings(it6625, timings);
+	if (ret)
+		return ret;
+
+	if (debug)
+		v4l2_print_dv_timings(sd->name, __func__, timings, false);
+
+	if (!v4l2_valid_dv_timings(timings, it6625_get_timings_cap(it6625), NULL, NULL)) {
+		v4l2_dbg(1, debug, sd, "%s: timings out of range", __func__);
+		return -ERANGE;
+	}
+
+	return 0;
+}
+
+static inline u32 format_to_colorspace(u8 csi_format)
+{
+	switch (csi_format) {
+	case CSI_RGB444:
+	case CSI_RGB555:
+	case CSI_RGB565:
+	case CSI_RGB666:
+	case CSI_RGB888:
+	case CSI_RGB_10b:
+	case CSI_RGB_12b:
+		return V4L2_COLORSPACE_SRGB;
+	case CSI_YUV420_8b_L:
+	case CSI_YUV420_8b:
+	case CSI_YUV420_10b:
+	case CSI_YUV422_8b:
+	case CSI_YUV422_10b:
+	case CSI_YUV422_12b:
+	case CSI_YUV420_10b_L:
+	case CSI_YUV420_12b:
+	case CSI_YUV444_8b:
+	case CSI_YUV444_10b:
+	case CSI_YUV444_12b:
+		return V4L2_COLORSPACE_REC709;
+	default:
+		return 0;
+	}
+}
+
+static int it6625_get_fmt(struct v4l2_subdev *sd,
+			  struct v4l2_subdev_state *sd_state,
+			  struct v4l2_subdev_format *format)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	struct v4l2_dv_timings timings;
+
+	if (format->pad != 0)
+		return -EINVAL;
+
+	it6625_get_timings(it6625, &timings);
+	format->format.width = timings.bt.width;
+	format->format.height = timings.bt.height;
+	format->format.field = timings.bt.interlaced == V4L2_DV_INTERLACED ?
+			       V4L2_FIELD_INTERLACED : V4L2_FIELD_NONE;
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
+		struct v4l2_mbus_framefmt *fmt;
+
+		fmt = v4l2_subdev_state_get_format(sd_state, format->pad);
+		format->format.code = fmt->code;
+		format->format.colorspace = fmt->colorspace;
+	} else {
+		scoped_guard(mutex, &it6625->it6625_lock) {
+			format->format.colorspace =
+				format_to_colorspace(it6625->csi_format);
+			format->format.code = it6625->mbus_fmt_code;
+		}
+	}
+
+	return 0;
+}
+
+static int it6625_set_fmt(struct v4l2_subdev *sd,
+			  struct v4l2_subdev_state *sd_state,
+			  struct v4l2_subdev_format *format)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int ret;
+	u32 mbus_fmt_code = format->format.code;
+
+	ret = it6625_get_fmt(sd, sd_state, format);
+	format->format.code = mbus_fmt_code;
+
+	if (ret)
+		return ret;
+
+	ret = it6625_csi_mbus_code_idx(mbus_fmt_code);
+
+	if (ret < 0) {
+		v4l2_dbg(1, debug, sd,
+			 "%s: unsupported format code 0x%x, falling back to default",
+			 __func__, mbus_fmt_code);
+		ret = 0;
+		mbus_fmt_code = it6625_formats[ret].mbus_fmt_code;
+		format->format.code = mbus_fmt_code;
+	}
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
+		struct v4l2_mbus_framefmt *fmt;
+
+		fmt = v4l2_subdev_state_get_format(sd_state, format->pad);
+		fmt->code = format->format.code;
+		fmt->colorspace = format_to_colorspace(it6625_formats[ret].csi_format);
+		format->format.colorspace = fmt->colorspace;
+		v4l2_dbg(1, debug, sd, "%s: try format code = 0x%x",
+			 __func__, format->format.code);
+		return 0;
+	}
+
+	scoped_guard(mutex, &it6625->it6625_lock) {
+		it6625->csi_format = it6625_formats[ret].csi_format;
+		it6625->mbus_fmt_code = format->format.code;
+		it6625_enable_stream_locked(it6625, false);
+		it6625_set_mipi_config_locked(it6625, it6625->csi_format);
+	}
+
+	format->format.colorspace = format_to_colorspace(it6625_formats[ret].csi_format);
+
+	return 0;
+}
+
+static int it6625_g_edid(struct v4l2_subdev *sd,
+			 struct v4l2_subdev_edid *edid)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int err;
+
+	if (edid->pad != 0)
+		return -EINVAL;
+
+	memset(edid->reserved, 0, sizeof(edid->reserved));
+
+	guard(mutex)(&it6625->edid_lock);
+
+	if (edid->start_block == 0 && edid->blocks == 0) {
+		edid->blocks = it6625->edid_blocks;
+		return 0;
+	}
+
+	if (it6625->edid_blocks == 0)
+		return -ENODATA;
+
+	if (edid->start_block >= it6625->edid_blocks || edid->blocks == 0)
+		return -EINVAL;
+
+	if (edid->blocks > it6625->edid_blocks - edid->start_block)
+		edid->blocks = it6625->edid_blocks - edid->start_block;
+
+	err = it6625_read_edid(it6625, edid->edid, edid->start_block,
+			       edid->blocks);
+
+	return (err < 0) ? err : 0;
+}
+
+static int it6625_s_edid(struct v4l2_subdev *sd,
+			 struct v4l2_subdev_edid *edid)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int err;
+	u16 parent_pa = CEC_PHYS_ADDR_INVALID;
+
+	if (edid->pad != 0) {
+		v4l2_err(sd, "invalid pad %d", edid->pad);
+		return -EINVAL;
+	}
+
+	memset(edid->reserved, 0, sizeof(edid->reserved));
+
+	if (edid->start_block != 0) {
+		v4l2_err(sd, "start_block must be 0 for set edid");
+		return -EINVAL;
+	}
+
+	if (edid->blocks > EDID_NUM_BLOCKS_MAX) {
+		v4l2_err(sd, "too many edid blocks: %d", edid->blocks);
+		edid->blocks = EDID_NUM_BLOCKS_MAX;
+		return -E2BIG;
+	}
+
+	if (edid->blocks != 0) {
+		u16 pa = v4l2_get_edid_phys_addr(edid->edid,
+						 edid->blocks * 128, NULL);
+		err = v4l2_phys_addr_validate(pa, &parent_pa, NULL);
+		if (err) {
+			v4l2_err(sd, "invalid CEC physical address in EDID");
+			return err;
+		}
+	}
+
+	guard(mutex)(&it6625->edid_lock);
+
+	it6625_disable_hpd(it6625);
+	cec_phys_addr_invalidate(it6625->cec_adap);
+	it6625->edid_blocks = 0;
+
+	if (edid->blocks == 0)
+		return 0;
+
+	err = it6625_write_edid(it6625, edid->edid,
+				edid->start_block, edid->blocks);
+	if (err < 0) {
+		v4l2_err(sd, "write edid failed");
+		return err;
+	}
+
+	it6625->edid_blocks = edid->blocks;
+	cec_s_phys_addr(it6625->cec_adap, parent_pa, false);
+
+	if (hdmi_5v_power_present(it6625)) {
+		it6625_enable_hpd(it6625);
+		it6625_s_ctrl_detect_hdmi_5v(sd);
+	} else {
+		it6625_enable_auto_hpd(it6625);
+	}
+
+	return 0;
+}
+
+static const struct v4l2_subdev_core_ops it6625_core_ops = {
+	.log_status = it6625_log_status,
+	.interrupt_service_routine = it6625_isr,
+	.subscribe_event = it6625_subscribe_event,
+	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
+static const struct v4l2_subdev_video_ops it6625_video_ops = {
+	.g_input_status = it6625_g_input_status,
+	.s_stream = it6625_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops it6625_pad_ops = {
+	.enum_mbus_code = it6625_enum_mbus_code,
+	.set_fmt = it6625_set_fmt,
+	.get_fmt = it6625_get_fmt,
+	.get_edid = it6625_g_edid,
+	.set_edid = it6625_s_edid,
+	.enum_dv_timings = it6625_enum_dv_timings,
+	.dv_timings_cap = it6625_dv_timings_cap,
+	.get_mbus_config = it6625_get_mbus_config,
+	.s_dv_timings = it6625_pad_s_dv_timings,
+	.g_dv_timings = it6625_pad_g_dv_timings,
+	.query_dv_timings = it6625_pad_query_dv_timings,
+};
+
+static const struct v4l2_subdev_ops it6625_ops = {
+	.core = &it6625_core_ops,
+	.video = &it6625_video_ops,
+	.pad = &it6625_pad_ops,
+};
+
+static int it6625_init_state(struct v4l2_subdev *sd,
+			     struct v4l2_subdev_state *sd_state)
+{
+	struct v4l2_mbus_framefmt *fmt = v4l2_subdev_state_get_format(sd_state, 0);
+
+	fmt->code = it6625_formats[0].mbus_fmt_code;
+	fmt->colorspace = format_to_colorspace(it6625_formats[0].csi_format);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops it6625_internal_ops = {
+	.init_state = it6625_init_state,
+};
+
+static const struct v4l2_ctrl_config it6625_ctrl_audio_sampling_rate = {
+	.id = V4L2_CID_IT6625_AUDIO_SAMPLING_RATE,
+	.name = "Audio Sampling Rate",
+	.type = V4L2_CTRL_TYPE_INTEGER,
+	.min = 0,
+	.max = 1536000,
+	.step = 1,
+	.def = 0,
+	.flags = V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config it6625_ctrl_audio_present = {
+	.id = V4L2_CID_IT6625_AUDIO_PRESENT,
+	.name = "Audio Present",
+	.type = V4L2_CTRL_TYPE_BOOLEAN,
+	.min = 0,
+	.max = 1,
+	.step = 1,
+	.def = 0,
+	.flags = V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static int it6625_v4l2_init_controls(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	struct v4l2_ctrl_handler *hdl = &it6625->hdl;
+
+	v4l2_ctrl_handler_init(hdl, 4);
+	it6625->ctrl_5v_detect =
+		v4l2_ctrl_new_std(hdl, NULL, V4L2_CID_DV_RX_POWER_PRESENT,
+				  0, 1, 0, 0);
+
+	it6625->ctrl_audio_sampling_rate =
+		v4l2_ctrl_new_custom(hdl,
+				     &it6625_ctrl_audio_sampling_rate,
+				     NULL);
+	it6625->ctrl_audio_present =
+		v4l2_ctrl_new_custom(hdl, &it6625_ctrl_audio_present, NULL);
+	it6625->ctrl_link_freq =
+		v4l2_ctrl_new_int_menu(hdl, NULL, V4L2_CID_LINK_FREQ,
+				       ARRAY_SIZE(it6625_link_freq) - 1,
+				       it6625->bus_type == V4L2_MBUS_CSI2_CPHY ? 1 : 0,
+				       it6625_link_freq);
+	if (hdl->error) {
+		v4l2_err(sd, "Failed to initialize controls");
+		v4l2_ctrl_handler_free(hdl);
+		return hdl->error;
+	}
+
+	sd->ctrl_handler = hdl;
+
+	return 0;
+}
+
+static void it6625_regdump_print(struct seq_file *s, const u8 *reg_buf)
+{
+	int i;
+
+	seq_puts(s, "     0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F\n");
+
+	for (i = 0; i < 256; i++) {
+		if (i % 16 == 0)
+			seq_printf(s, "[%02X] ", i & 0xF0);
+		seq_printf(s, "0x%02X ", reg_buf[i]);
+		if (i % 16 == 15)
+			seq_putc(s, '\n');
+	}
+}
+
+static int it6625_mipi_reg_show(struct seq_file *s, void *data)
+{
+	struct it6625 *it6625 = s->private;
+	u8 reg_buf[256];
+	int ret;
+
+	scoped_guard(mutex, &it6625->it6625_lock)
+		ret = it6625_read_bytes(it6625, 0x00, reg_buf, sizeof(reg_buf));
+	if (ret < 0)
+		return ret;
+	it6625_regdump_print(s, reg_buf);
+
+	return 0;
+}
+
+static int it6625_mipi_reg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, it6625_mipi_reg_show, inode->i_private);
+}
+
+static ssize_t it6625_mipi_reg_write(struct file *file,
+				     const char __user *user_buf,
+				     size_t count, loff_t *ppos)
+{
+	struct it6625 *it6625 = file_inode(file)->i_private;
+	char buf[32] = {};
+	unsigned int addr, val;
+	ssize_t len;
+	loff_t pos = 0;
+
+	len = simple_write_to_buffer(buf, sizeof(buf) - 1, &pos, user_buf, count);
+	if (len < 0)
+		return len;
+	buf[len] = '\0';
+
+	if (sscanf(buf, "%X %X", &addr, &val) != 2)
+		return -EINVAL;
+
+	scoped_guard(mutex, &it6625->it6625_lock)
+		it6625_write_byte(it6625, addr, val);
+
+	return count;
+}
+
+static const struct file_operations it6625_mipi_reg_fops = {
+	.owner = THIS_MODULE,
+	.open = it6625_mipi_reg_open,
+	.read = seq_read,
+	.write = it6625_mipi_reg_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+/*
+ * Maps a V4L2_DEBUGFS_IF_* framework flag to the actual HDMI packet-type
+ * header byte REG_IF_LATCH_HB expects to arm that InfoFrame type.
+ */
+static int it6625_if_packet_type(u32 type)
+{
+	switch (type) {
+	case V4L2_DEBUGFS_IF_AVI:
+		return 0x82;
+	case V4L2_DEBUGFS_IF_AUDIO:
+		return 0x84;
+	case V4L2_DEBUGFS_IF_SPD:
+		return 0x83;
+	case V4L2_DEBUGFS_IF_HDMI:
+		return 0x81;
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t it6625_debugfs_if_read(u32 type, void *priv, struct file *filp,
+				      char __user *ubuf, size_t count,
+				      loff_t *ppos)
+{
+	struct v4l2_subdev *sd = priv;
+	struct it6625 *it6625 = sd_to_6625(sd);
+	u8 buf[32] = {};
+	int packet_type;
+	int err, err_reset;
+	bool captured;
+	int len;
+
+	packet_type = it6625_if_packet_type(type);
+	if (packet_type < 0)
+		return 0;
+
+	guard(mutex)(&it6625->if_read_lock);
+
+	scoped_guard(mutex, &it6625->if_state_lock) {
+		scoped_guard(mutex, &it6625->it6625_lock)
+			err = it6625_write_byte(it6625, REG_IF_LATCH_HB, 0);
+		if (err)
+			return err;
+
+		err = it6625_drain_interrupts(it6625, NULL);
+		if (err)
+			return err;
+
+		reinit_completion(&it6625->if_latched);
+
+		it6625->if_active = true;
+		it6625->if_type = packet_type;
+		it6625->if_snapshot_done = false;
+		it6625->if_snapshot_err = 0;
+
+		scoped_guard(mutex, &it6625->it6625_lock)
+			err = it6625_write_byte(it6625, REG_IF_LATCH_HB,
+						packet_type);
+		if (err) {
+			scoped_guard(mutex, &it6625->it6625_lock)
+				it6625_write_byte(it6625, REG_IF_LATCH_HB, 0);
+			it6625->if_active = false;
+			return err;
+		}
+	}
+
+	wait_for_completion_timeout(&it6625->if_latched, msecs_to_jiffies(100));
+
+	scoped_guard(mutex, &it6625->if_state_lock) {
+		captured = it6625->if_snapshot_done;
+		it6625->if_active = false;
+
+		scoped_guard(mutex, &it6625->it6625_lock)
+			err_reset = it6625_write_byte(it6625, REG_IF_LATCH_HB, 0);
+
+		if (!captured) {
+			if (err_reset)
+				return err_reset;
+			return 0;
+		}
+
+		if (!it6625->if_snapshot_err) {
+			buf[0] = packet_type;
+			memcpy(&buf[1], it6625->if_snapshot, 31);
+		}
+
+		err = it6625->if_snapshot_err ? it6625->if_snapshot_err : err_reset;
+		if (err)
+			return err;
+	}
+
+	len = buf[2] ? buf[2] + 4 : -ENOENT;
+	if (len > (int)sizeof(buf))
+		len = -ENOENT;
+	if (len < 0)
+		return 0;
+	return simple_read_from_buffer(ubuf, count, ppos, buf, len);
+}
+
+static void it6625_debugfs_init(struct it6625 *it6625, struct i2c_client *client)
+{
+	it6625->debugfs_dir = debugfs_create_dir(dev_name(&client->dev), NULL);
+
+	debugfs_create_file("mipi_reg", 0600, it6625->debugfs_dir, it6625,
+			    &it6625_mipi_reg_fops);
+
+	it6625->infoframes = v4l2_debugfs_if_alloc(it6625->debugfs_dir,
+						   V4L2_DEBUGFS_IF_AVI | V4L2_DEBUGFS_IF_AUDIO |
+						   V4L2_DEBUGFS_IF_SPD | V4L2_DEBUGFS_IF_HDMI,
+						   &it6625->sd, it6625_debugfs_if_read);
+}
+
+static void it6625_init_data(struct it6625 *it6625)
+{
+	static struct v4l2_dv_timings default_timing =
+			V4L2_DV_BT_CEA_1920X1080P60;
+
+	it6625->csi_lanes = 4;
+	it6625->port_num = 1;
+	it6625->bus_type = V4L2_MBUS_CSI2_DPHY;
+	it6625->csi_format = it6625_formats[0].csi_format;
+	it6625->mbus_fmt_code = it6625_formats[0].mbus_fmt_code;
+	it6625->timings = default_timing;
+	/* firmware ships with a verified 2-block default EDID in EDID RAM */
+	it6625->edid_blocks = 2;
+}
+
+static int it6625_parse_endpoint(struct it6625 *it6625)
+{
+	struct device *dev = it6625->dev;
+	/*
+	 * Pre-setting bus_type here makes v4l2_fwnode_endpoint_alloc_parse()
+	 * treat it as a hard requirement and reject any endpoint whose DT
+	 * bus-type disagrees, so this must stay V4L2_MBUS_UNKNOWN to let it
+	 * autodetect C-PHY vs D-PHY from the endpoint itself.
+	 */
+	struct v4l2_fwnode_endpoint endpoint = { .bus_type = V4L2_MBUS_UNKNOWN };
+	struct device_node *ep = NULL;
+	unsigned int max_lanes;
+	unsigned int port;
+	int ret;
+
+	/*
+	 * port@0 and port@1 are the two CSI-2 output ports MIPI0/MIPI1
+	 * (port@2 is the HDMI input). This chip series can drive both
+	 * simultaneously in split or mirror mode, so port_num counts how
+	 * many of MIPI0/MIPI1 have an endpoint wired up. This driver only
+	 * wires up a single source pad, so lane/bus-type configuration is
+	 * parsed from whichever of the two is found first.
+	 */
+	it6625->port_num = 0;
+	for (port = 0; port < 2; port++) {
+		struct device_node *port_ep =
+			of_graph_get_endpoint_by_regs(dev->of_node, port, -1);
+
+		if (!port_ep)
+			continue;
+
+		it6625->port_num++;
+		if (!ep)
+			ep = port_ep;
+		else
+			of_node_put(port_ep);
+	}
+
+	if (!ep) {
+		it6625->port_num = 1;
+		dev_dbg(dev, "no CSI-2 endpoint node found, using default %u CSI lanes",
+			it6625->csi_lanes);
+		return 0;
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(of_fwnode_handle(ep), &endpoint);
+	of_node_put(ep);
+	if (ret) {
+		dev_err(dev, "failed to parse endpoint: %d", ret);
+		return ret;
+	}
+
+	if (endpoint.bus_type != V4L2_MBUS_CSI2_DPHY &&
+	    endpoint.bus_type != V4L2_MBUS_CSI2_CPHY) {
+		dev_err(dev, "unsupported bus type %d, expected CSI-2 D-PHY or C-PHY",
+			endpoint.bus_type);
+		v4l2_fwnode_endpoint_free(&endpoint);
+		return -EINVAL;
+	}
+
+	if (endpoint.bus_type == V4L2_MBUS_CSI2_CPHY &&
+	    it6625->chip_type != IT6626_CHIP) {
+		dev_err(dev, "IT6625 does not support C-PHY, only IT6626 does");
+		v4l2_fwnode_endpoint_free(&endpoint);
+		return -EINVAL;
+	}
+
+	max_lanes = (endpoint.bus_type == V4L2_MBUS_CSI2_CPHY) ? 3 : 4;
+
+	if (endpoint.bus.mipi_csi2.num_data_lanes == 0 ||
+	    endpoint.bus.mipi_csi2.num_data_lanes > max_lanes) {
+		dev_err(dev,
+			"invalid number of CSI data lanes: %u (max %u for this bus type)",
+			endpoint.bus.mipi_csi2.num_data_lanes, max_lanes);
+		v4l2_fwnode_endpoint_free(&endpoint);
+		return -EINVAL;
+	}
+
+	it6625->csi_lanes = endpoint.bus.mipi_csi2.num_data_lanes;
+	it6625->bus_type = endpoint.bus_type;
+	v4l2_fwnode_endpoint_free(&endpoint);
+
+	return 0;
+}
+
+static int it6625_parse_dt(struct it6625 *it6625)
+{
+	return it6625_parse_endpoint(it6625);
+}
+
+static int it6625_init_v4l2_subdev(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int err;
+
+	sd->dev = it6625->dev;
+
+	v4l2_i2c_subdev_init(sd, it6625->i2c_client, &it6625_ops);
+	sd->internal_ops = &it6625_internal_ops;
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
+	if (it6625_v4l2_init_controls(sd)) {
+		dev_err(it6625->dev, "Failed to initialize v4l2 controls");
+		return -ENOMEM;
+	}
+
+	it6625->pad.flags = MEDIA_PAD_FL_SOURCE;
+	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	err = media_entity_pads_init(&sd->entity, 1, &it6625->pad);
+	if (err < 0) {
+		dev_err(it6625->dev, "%s %d err=%d", __func__, __LINE__, err);
+		v4l2_ctrl_handler_free(sd->ctrl_handler);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_check_device(struct it6625 *it6625)
+{
+	static const u8 chip_ids[][2] = {
+		{ 0x66, 0x25 },
+		{ 0x66, 0x26 },
+	};
+	int chip_id0, chip_id1;
+
+	chip_id0 = it6625_read_byte(it6625, REG_CHIP_ID_0);
+	chip_id1 = it6625_read_byte(it6625, REG_CHIP_ID_1);
+	if (chip_id0 != chip_ids[it6625->chip_type][0] ||
+	    chip_id1 != chip_ids[it6625->chip_type][1]) {
+		dev_err(it6625->dev,
+			"chip ID mismatch: got 0x%02x%02x, expected 0x%02x%02x",
+			chip_id0, chip_id1,
+			chip_ids[it6625->chip_type][0],
+			chip_ids[it6625->chip_type][1]);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int it6625_probe(struct i2c_client *client)
+{
+	struct it6625 *it6625;
+	struct v4l2_subdev *sd;
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -EIO;
+
+	it6625 = devm_kzalloc(&client->dev, sizeof(struct it6625), GFP_KERNEL);
+	if (!it6625)
+		return -ENOMEM;
+
+	it6625->chip_type = (uintptr_t)i2c_get_match_data(client);
+
+	it6625->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+						     GPIOD_OUT_HIGH);
+	if (IS_ERR(it6625->reset_gpio))
+		return PTR_ERR(it6625->reset_gpio);
+
+	if (it6625->reset_gpio) {
+		usleep_range(1000, 2000);
+		gpiod_set_value_cansleep(it6625->reset_gpio, 0);
+		usleep_range(10000, 11000);
+	}
+
+	err = it6625_regmap_i2c_init(client, it6625);
+	if (err)
+		return err;
+
+	err = it6625_check_device(it6625);
+	if (err)
+		return err;
+
+	it6625_init_data(it6625);
+
+	err = it6625_parse_dt(it6625);
+	if (err)
+		return err;
+
+	mutex_init(&it6625->it6625_lock);
+	mutex_init(&it6625->edid_lock);
+	mutex_init(&it6625->if_read_lock);
+	mutex_init(&it6625->if_state_lock);
+	init_completion(&it6625->if_latched);
+	INIT_DELAYED_WORK(&it6625->hpd_delayed_work, it6625_hpd_delayed_work);
+	INIT_WORK(&it6625->polling_work, it6625_polling_work);
+
+	if (client->irq) {
+		err = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, it6625_irq_handler,
+						IRQF_ONESHOT |
+						IRQF_NO_AUTOEN,
+						"it6625", it6625);
+		if (err)
+			goto err_clean_work_queues;
+	} else {
+		dev_info(it6625->dev, "no IRQ, falling back to polling");
+		timer_setup(&it6625->timer, it6625_irq_poll_timer, 0);
+	}
+
+	sd = &it6625->sd;
+	err = it6625_init_v4l2_subdev(it6625);
+	if (err)
+		goto err_clean_work_queues;
+
+	err = v4l2_ctrl_handler_setup(sd->ctrl_handler);
+	if (err)
+		goto err_clean_hdl;
+
+	it6625->cec_adap = cec_allocate_adapter(&it6625_cec_adap_ops,
+						it6625, dev_name(it6625->dev),
+						CEC_CAP_DEFAULTS |
+						CEC_CAP_MONITOR_ALL |
+						CEC_CAP_PHYS_ADDR,
+						1);
+	if (IS_ERR(it6625->cec_adap)) {
+		err = PTR_ERR(it6625->cec_adap);
+		dev_err(it6625->dev, "%s %d", __func__, __LINE__);
+		goto err_clean_hdl;
+	}
+
+	err = cec_register_adapter(it6625->cec_adap, &client->dev);
+	if (err < 0) {
+		dev_err(it6625->dev, "%s: failed to register the cec device", __func__);
+		cec_delete_adapter(it6625->cec_adap);
+		it6625->cec_adap = NULL;
+		goto err_clean_hdl;
+	}
+
+	it6625_debugfs_init(it6625, client);
+
+	it6625_initial_setup(it6625);
+	it6625_v4l2_sd_ctrl_update(sd);
+
+	err = v4l2_async_register_subdev(sd);
+	if (err < 0) {
+		dev_err(it6625->dev, "%s %d err=%d", __func__, __LINE__, err);
+		goto err_clean_debugfs;
+	}
+
+	if (client->irq)
+		enable_irq(client->irq);
+	else
+		mod_timer(&it6625->timer, jiffies + msecs_to_jiffies(POLL_INTERVAL_MS));
+
+	return 0;
+
+err_clean_debugfs:
+	v4l2_debugfs_if_free(it6625->infoframes);
+	debugfs_remove_recursive(it6625->debugfs_dir);
+	cec_unregister_adapter(it6625->cec_adap);
+err_clean_hdl:
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(&it6625->hdl);
+
+err_clean_work_queues:
+	if (!client->irq)
+		timer_shutdown_sync(&it6625->timer);
+	cancel_work_sync(&it6625->polling_work);
+	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
+	mutex_destroy(&it6625->it6625_lock);
+	mutex_destroy(&it6625->edid_lock);
+	mutex_destroy(&it6625->if_read_lock);
+	mutex_destroy(&it6625->if_state_lock);
+	return err;
+}
+
+static void it6625_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	v4l2_debugfs_if_free(it6625->infoframes);
+
+	if (client->irq)
+		disable_irq(client->irq);
+	else
+		timer_shutdown_sync(&it6625->timer);
+
+	cancel_work_sync(&it6625->polling_work);
+	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
+
+	v4l2_async_unregister_subdev(sd);
+	v4l2_device_unregister_subdev(sd);
+
+	debugfs_remove_recursive(it6625->debugfs_dir);
+	cec_unregister_adapter(it6625->cec_adap);
+	mutex_destroy(&it6625->it6625_lock);
+	mutex_destroy(&it6625->edid_lock);
+	mutex_destroy(&it6625->if_read_lock);
+	mutex_destroy(&it6625->if_state_lock);
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(&it6625->hdl);
+}
+
+static const struct i2c_device_id it6625_id[] = {
+	{ .name = "it6625", .driver_data = IT6625_CHIP },
+	{ .name = "it6626", .driver_data = IT6626_CHIP },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, it6625_id);
+
+static const struct of_device_id it6625_of_match[] = {
+	{ .compatible = "ite,it6625", .data = (void *)IT6625_CHIP },
+	{ .compatible = "ite,it6626", .data = (void *)IT6626_CHIP },
+	{},
+};
+MODULE_DEVICE_TABLE(of, it6625_of_match);
+
+static struct i2c_driver it6625_driver = {
+	.driver = {
+		.name = "it6625",
+		.of_match_table = it6625_of_match,
+	},
+	.probe = it6625_probe,
+	.remove = it6625_remove,
+	.id_table = it6625_id,
+};
+module_i2c_driver(it6625_driver);
+
+MODULE_DESCRIPTION("iTE it6625/it6626 HDMI to MIPI CSI bridge driver");
+MODULE_AUTHOR("Hermes Wu <Hermes.wu@ite.com.tw>");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/it6625.h b/include/uapi/linux/it6625.h
new file mode 100644
index 000000000000..a895658aaf6a
--- /dev/null
+++ b/include/uapi/linux/it6625.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Controls header for IT6625/IT6626 driver
+ */
+
+#ifndef _UAPI_LINUX_IT6625_H
+#define _UAPI_LINUX_IT6625_H
+
+#include <linux/v4l2-controls.h>
+
+/*
+ * Currently detected HDMI audio sampling rate, in Hz. Read-only.
+ * 0 means the rate is unavailable/unknown: no audio is currently
+ * present on the input, the hardware reported a sample-rate id this
+ * driver doesn't recognize, or the status read itself failed. Never a
+ * literal 0 Hz sample rate.
+ */
+#define V4L2_CID_IT6625_AUDIO_SAMPLING_RATE	(V4L2_CID_USER_IT6625_BASE + 0)
+
+/*
+ * Whether HDMI audio is currently present on the input. Read-only.
+ */
+#define V4L2_CID_IT6625_AUDIO_PRESENT		(V4L2_CID_USER_IT6625_BASE + 1)
+
+#endif /* _UAPI_LINUX_IT6625_H */
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 42b4f82afeb8..3a2c0a7ba5e2 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -240,6 +240,12 @@ enum v4l2_colorfx {
  */
 #define V4L2_CID_USER_DCMIPP_BASE		(V4L2_CID_USER_BASE + 0x1240)
 
+/*
+ * The base for IT6625/IT6626 driver controls.
+ * We reserve 16 controls for this driver.
+ */
+#define V4L2_CID_USER_IT6625_BASE		(V4L2_CID_USER_BASE + 0x1250)
+
 /* MPEG-class control IDs */
 /* The MPEG controls are applicable to all codec controls
  * and the 'MPEG' part of the define is historical */