From: Guoniu Zhou <guoniu.zhou@nxp.com>

The CSI pixel formatter is a module found on i.MX95 used to reformat
packet info, pixel and non-pixel data from CSI-2 host controller to
match Pixel Link(PL) definition.

Add data formatting support.

Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
 MAINTAINERS                                     |   8 +
 drivers/media/platform/nxp/Kconfig              |  14 +
 drivers/media/platform/nxp/Makefile             |   1 +
 drivers/media/platform/nxp/imx9-csi-formatter.c | 881 ++++++++++++++++++++++++
 4 files changed, 904 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 4205ca007e076f869613032b51e8cc5bff06b98e..24681a787818c3e69f93dcc220ee9838cef99886 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18626,6 +18626,14 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
 F:	drivers/media/platform/nxp/imx-jpeg
 
+NXP i.MX 9 CSI PIXEL FORMATTER V4L2 DRIVER
+M:	Guoniu Zhou <guoniu.zhou@nxp.com>
+L:	imx@lists.linux.dev
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/media/nxp,imx9-csi-formatter.yaml
+F:	drivers/media/platform/nxp/imx9-csi-formatter.c
+
 NXP i.MX CLOCK DRIVERS
 M:	Abel Vesa <abelvesa@kernel.org>
 R:	Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/media/platform/nxp/Kconfig b/drivers/media/platform/nxp/Kconfig
index 40e3436669e213fdc5da70821dc0b420e1821f4f..a7bb62a2b0249659ffdfeac50fa488aee9590a87 100644
--- a/drivers/media/platform/nxp/Kconfig
+++ b/drivers/media/platform/nxp/Kconfig
@@ -28,6 +28,20 @@ config VIDEO_IMX8MQ_MIPI_CSI2
 	  Video4Linux2 driver for the MIPI CSI-2 receiver found on the i.MX8MQ
 	  SoC.
 
+config VIDEO_IMX9_CSI_FORMATTER
+	tristate "NXP i.MX9 CSI Pixel Formatter driver"
+	depends on ARCH_MXC || COMPILE_TEST
+	depends on VIDEO_DEV
+	select MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	  This driver provides support for the CSI Pixel Formatter found on
+	  i.MX9 series SoC. This module unpacks the pixels received by the
+	  formatter and reformats them to meet the pixel link format requirement.
+
+	  Say Y here to enable CSI Pixel Formater module for i.MX9 SoC.
+
 config VIDEO_IMX_MIPI_CSIS
 	tristate "NXP MIPI CSI-2 CSIS receiver found on i.MX7 and i.MX8 models"
 	depends on ARCH_MXC || COMPILE_TEST
diff --git a/drivers/media/platform/nxp/Makefile b/drivers/media/platform/nxp/Makefile
index 4d90eb71365259ebdda84ea58483e1c4131d3ac7..39ba5660ba923141e7637b01b5b34a021dad7bb3 100644
--- a/drivers/media/platform/nxp/Makefile
+++ b/drivers/media/platform/nxp/Makefile
@@ -6,6 +6,7 @@ obj-y += imx8-isi/
 
 obj-$(CONFIG_VIDEO_IMX7_CSI) += imx7-media-csi.o
 obj-$(CONFIG_VIDEO_IMX8MQ_MIPI_CSI2) += imx8mq-mipi-csi2.o
+obj-$(CONFIG_VIDEO_IMX9_CSI_FORMATTER) += imx9-csi-formatter.o
 obj-$(CONFIG_VIDEO_IMX_MIPI_CSIS) += imx-mipi-csis.o
 obj-$(CONFIG_VIDEO_IMX_PXP) += imx-pxp.o
 obj-$(CONFIG_VIDEO_MX2_EMMAPRP) += mx2_emmaprp.o
diff --git a/drivers/media/platform/nxp/imx9-csi-formatter.c b/drivers/media/platform/nxp/imx9-csi-formatter.c
new file mode 100644
index 0000000000000000000000000000000000000000..62ba929639d2ef0ea1b5134153c286d0d511688d
--- /dev/null
+++ b/drivers/media/platform/nxp/imx9-csi-formatter.c
@@ -0,0 +1,881 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include <media/mipi-csi2.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+#include <media/v4l2-subdev.h>
+
+/* CSI Pixel Formatter registers map */
+
+#define CSI_VCx_INTERLACED_LINE_CNT(x)		(0x00 + (x) * 0x04)
+#define INTERLACED_ODD_LINE_CNT_SET(x)		FIELD_PREP(GENMASK(13, 0), (x))
+#define INTERLACED_EVEN_LINE_CNT_SET(x)		FIELD_PREP(GENMASK(29, 16), (x))
+
+#define CSI_VC_INTERLACED_CTRL			0x20
+
+#define CSI_VC_INTERLACED_ERR			0x24
+#define CSI_VC_ERR_MASK				GENMASK(7, 0)
+#define CSI_VC_ERR(vc)				BIT((vc))
+
+#define CSI_VC_YUV420_FIRST_LINE_EVEN		0x28
+#define YUV420_FIRST_LINE_EVEN(vc)		BIT((vc))
+
+#define CSI_RAW32_CTRL				0x30
+#define CSI_VCX_RAW32_MODE(vc)			BIT((vc))
+#define CSI_VCX_RAW32_SWAP_MODE(vc)		BIT((vc) + 8)
+
+#define STREAM_FENCING_CTRL			0x34
+#define CSI_VCx_STREAM_FENCING(vc)		BIT((vc))
+#define CSI_VCx_STREAM_FENCING_RST(vc)		BIT((vc) + 8)
+
+#define STREAM_FENCING_STS			0x38
+#define STREAM_FENCING_STS_MASK			GENMASK(7, 0)
+
+#define CSI_VCX_NON_PIXEL_DATA_TYPE(vc)		(0x40 + (vc) * 0x04)
+
+#define CSI_VCX_PIXEL_DATA_CTRL(vc)		(0x60 + (vc) * 0x04)
+#define NEW_VC(x)				FIELD_PREP(GENMASK(3, 1), x)
+#define REROUTE_VC_ENABLE			BIT(0)
+
+#define CSI_VCx_ROUTE_PIXEL_DATA_TYPE(vc)	(0x80 + (vc) * 0x04)
+
+#define CSI_VCx_NON_PIXEL_DATA_CTRL(vc)		(0xa0 + (vc) * 0x04)
+
+#define CSI_VCx_PIXEL_DATA_TYPE(vc)		(0xc0 + (vc) * 0x04)
+
+#define CSI_VCx_PIXEL_DATA_TYPE_ERR(vc)		(0xe0 + (vc) * 0x04)
+
+#define CSI_FORMATTER_PAD_SINK			0
+#define CSI_FORMATTER_PAD_SOURCE		1
+#define CSI_FORMATTER_PAD_NUM			2
+
+#define CSI_FORMATTER_DRV_NAME			"csi-pixel-formatter"
+#define CSI_FORMATTER_VC_MAX			8
+
+struct formatter_pix_format {
+	u32 code;
+	u32 data_type;
+};
+
+struct csi_formatter {
+	struct device *dev;
+	struct regmap *regs;
+	struct clk *clk;
+
+	struct v4l2_subdev sd;
+	struct v4l2_subdev *csi_sd;
+	struct v4l2_async_notifier notifier;
+	struct v4l2_mbus_framefmt format[CSI_FORMATTER_PAD_NUM];
+	struct media_pad pads[CSI_FORMATTER_PAD_NUM];
+	const struct formatter_pix_format *fmt;
+
+	u16 remote_pad;
+	u32 reg_offset;
+	u64 enabled_streams;
+};
+
+struct dt_index {
+	u8 dtype;
+	u8 index;
+};
+
+static const struct dt_index formatter_dt_to_index_map[] = {
+	{ .dtype = MIPI_CSI2_DT_YUV420_8B,        .index = 0 },
+	{ .dtype = MIPI_CSI2_DT_YUV420_8B_LEGACY, .index = 2 },
+	{ .dtype = MIPI_CSI2_DT_YUV422_8B,        .index = 6 },
+	{ .dtype = MIPI_CSI2_DT_RGB444,		  .index = 8 },
+	{ .dtype = MIPI_CSI2_DT_RGB555,           .index = 9 },
+	{ .dtype = MIPI_CSI2_DT_RGB565,           .index = 10 },
+	{ .dtype = MIPI_CSI2_DT_RGB666,           .index = 11 },
+	{ .dtype = MIPI_CSI2_DT_RGB888,           .index = 12 },
+	{ .dtype = MIPI_CSI2_DT_RAW6,             .index = 16 },
+	{ .dtype = MIPI_CSI2_DT_RAW7,             .index = 17 },
+	{ .dtype = MIPI_CSI2_DT_RAW8,             .index = 18 },
+	{ .dtype = MIPI_CSI2_DT_RAW10,            .index = 19 },
+	{ .dtype = MIPI_CSI2_DT_RAW12,            .index = 20 },
+	{ .dtype = MIPI_CSI2_DT_RAW14,            .index = 21 },
+	{ .dtype = MIPI_CSI2_DT_RAW16,            .index = 22 },
+};
+
+static const struct formatter_pix_format formats[] = {
+	/* YUV formats */
+	{
+		.code = MEDIA_BUS_FMT_UYVY8_1X16,
+		.data_type = MIPI_CSI2_DT_YUV422_8B,
+	},
+	/* RGB formats */
+	{
+		.code = MEDIA_BUS_FMT_RGB565_1X16,
+		.data_type = MIPI_CSI2_DT_RGB565,
+	}, {
+		.code = MEDIA_BUS_FMT_RGB888_1X24,
+		.data_type = MIPI_CSI2_DT_RGB888,
+	},
+	/* RAW (Bayer and greyscale) formats. */
+	{
+		.code = MEDIA_BUS_FMT_SBGGR8_1X8,
+		.data_type = MIPI_CSI2_DT_RAW8,
+	}, {
+		.code = MEDIA_BUS_FMT_SGBRG8_1X8,
+		.data_type = MIPI_CSI2_DT_RAW8,
+	}, {
+		.code = MEDIA_BUS_FMT_SGRBG8_1X8,
+		.data_type = MIPI_CSI2_DT_RAW8,
+	}, {
+		.code = MEDIA_BUS_FMT_SRGGB8_1X8,
+		.data_type = MIPI_CSI2_DT_RAW8,
+	}, {
+		.code = MEDIA_BUS_FMT_Y8_1X8,
+		.data_type = MIPI_CSI2_DT_RAW8,
+	}, {
+		.code = MEDIA_BUS_FMT_SBGGR10_1X10,
+		.data_type = MIPI_CSI2_DT_RAW10,
+	}, {
+		.code = MEDIA_BUS_FMT_SGBRG10_1X10,
+		.data_type = MIPI_CSI2_DT_RAW10,
+	}, {
+		.code = MEDIA_BUS_FMT_SGRBG10_1X10,
+		.data_type = MIPI_CSI2_DT_RAW10,
+	}, {
+		.code = MEDIA_BUS_FMT_SRGGB10_1X10,
+		.data_type = MIPI_CSI2_DT_RAW10,
+	}, {
+		.code = MEDIA_BUS_FMT_Y10_1X10,
+		.data_type = MIPI_CSI2_DT_RAW10,
+	}, {
+		.code = MEDIA_BUS_FMT_SBGGR12_1X12,
+		.data_type = MIPI_CSI2_DT_RAW12,
+	}, {
+		.code = MEDIA_BUS_FMT_SGBRG12_1X12,
+		.data_type = MIPI_CSI2_DT_RAW12,
+	}, {
+		.code = MEDIA_BUS_FMT_SGRBG12_1X12,
+		.data_type = MIPI_CSI2_DT_RAW12,
+	}, {
+		.code = MEDIA_BUS_FMT_SRGGB12_1X12,
+		.data_type = MIPI_CSI2_DT_RAW12,
+	}, {
+		.code = MEDIA_BUS_FMT_Y12_1X12,
+		.data_type = MIPI_CSI2_DT_RAW12,
+	}, {
+		.code = MEDIA_BUS_FMT_SBGGR14_1X14,
+		.data_type = MIPI_CSI2_DT_RAW14,
+	}, {
+		.code = MEDIA_BUS_FMT_SGBRG14_1X14,
+		.data_type = MIPI_CSI2_DT_RAW14,
+	}, {
+		.code = MEDIA_BUS_FMT_SGRBG14_1X14,
+		.data_type = MIPI_CSI2_DT_RAW14,
+	}, {
+		.code = MEDIA_BUS_FMT_SRGGB14_1X14,
+		.data_type = MIPI_CSI2_DT_RAW14,
+	}, {
+		.code = MEDIA_BUS_FMT_SBGGR16_1X16,
+		.data_type = MIPI_CSI2_DT_RAW16,
+	}, {
+		.code = MEDIA_BUS_FMT_SGBRG16_1X16,
+		.data_type = MIPI_CSI2_DT_RAW16,
+	}, {
+		.code = MEDIA_BUS_FMT_SGRBG16_1X16,
+		.data_type = MIPI_CSI2_DT_RAW16,
+	}, {
+		.code = MEDIA_BUS_FMT_SRGGB16_1X16,
+		.data_type = MIPI_CSI2_DT_RAW16,
+	}
+};
+
+static const struct v4l2_mbus_framefmt formatter_default_fmt = {
+	.code = MEDIA_BUS_FMT_UYVY8_1X16,
+	.width = 1920U,
+	.height = 1080U,
+	.field = V4L2_FIELD_NONE,
+	.colorspace = V4L2_COLORSPACE_SMPTE170M,
+	.xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(V4L2_COLORSPACE_SMPTE170M),
+	.ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(V4L2_COLORSPACE_SMPTE170M),
+	.quantization = V4L2_QUANTIZATION_LIM_RANGE,
+};
+
+static const struct formatter_pix_format *find_csi_format(u32 code)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(formats); i++)
+		if (code == formats[i].code)
+			return &formats[i];
+
+	return &formats[0];
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev operations
+ */
+
+static inline struct csi_formatter *sd_to_formatter(struct v4l2_subdev *sdev)
+{
+	return container_of(sdev, struct csi_formatter, sd);
+}
+
+static int __formatter_subdev_set_routing(struct v4l2_subdev *sd,
+					  struct v4l2_subdev_state *state,
+					  struct v4l2_subdev_krouting *routing)
+{
+	int ret;
+
+	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
+		return -EINVAL;
+
+	ret = v4l2_subdev_routing_validate(sd, routing,
+					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
+	if (ret)
+		return ret;
+
+	return v4l2_subdev_set_routing_with_fmt(sd, state, routing,
+						&formatter_default_fmt);
+}
+
+static int formatter_subdev_init_state(struct v4l2_subdev *sd,
+				       struct v4l2_subdev_state *sd_state)
+{
+	struct v4l2_subdev_route routes[] = {
+		{
+			.sink_pad = CSI_FORMATTER_PAD_SINK,
+			.sink_stream = 0,
+			.source_pad = CSI_FORMATTER_PAD_SOURCE,
+			.source_stream = 0,
+			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
+		},
+	};
+
+	struct v4l2_subdev_krouting routing = {
+		.num_routes = ARRAY_SIZE(routes),
+		.routes = routes,
+	};
+
+	return __formatter_subdev_set_routing(sd, sd_state, &routing);
+}
+
+static int formatter_subdev_enum_mbus_code(struct v4l2_subdev *sd,
+					   struct v4l2_subdev_state *sd_state,
+					   struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->pad == CSI_FORMATTER_PAD_SOURCE) {
+		struct v4l2_mbus_framefmt *fmt;
+
+		if (code->index > 0)
+			return -EINVAL;
+
+		fmt = v4l2_subdev_state_get_format(sd_state, code->pad,
+						   code->stream);
+		code->code = fmt->code;
+		return 0;
+	}
+
+	if (code->index >= ARRAY_SIZE(formats))
+		return -EINVAL;
+
+	code->code = formats[code->index].code;
+
+	return 0;
+}
+
+static int formatter_subdev_set_fmt(struct v4l2_subdev *sd,
+				    struct v4l2_subdev_state *sd_state,
+				    struct v4l2_subdev_format *sdformat)
+{
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+	struct formatter_pix_format const *format;
+	struct v4l2_mbus_framefmt *fmt;
+
+	if (sdformat->pad == CSI_FORMATTER_PAD_SOURCE)
+		return v4l2_subdev_get_fmt(sd, sd_state, sdformat);
+
+	/*
+	 * Validate the media bus code and clamp and align the size.
+	 *
+	 * The total number of bits per line must be a multiple of 8. We thus
+	 * need to align the width for formats that are not multiples of 8
+	 * bits.
+	 */
+	format = find_csi_format(sdformat->format.code);
+
+	v4l_bound_align_image(&sdformat->format.width, 1, 0xffff, 2,
+			      &sdformat->format.height, 1, 0xffff, 0, 0);
+
+	fmt = v4l2_subdev_state_get_format(sd_state, sdformat->pad,
+					   sdformat->stream);
+	*fmt = sdformat->format;
+
+	/* Set default code if user set an invalid value */
+	fmt->code = format->code;
+
+	/* Propagate the format from sink stream to source stream */
+	fmt = v4l2_subdev_state_get_opposite_stream_format(sd_state, sdformat->pad,
+							   sdformat->stream);
+	if (!fmt)
+		return -EINVAL;
+
+	*fmt = sdformat->format;
+
+	/* Store the CSIS format descriptor for active formats. */
+	if (sdformat->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+		formatter->fmt = format;
+
+	return 0;
+}
+
+static int formatter_subdev_get_frame_desc(struct v4l2_subdev *sd,
+					   unsigned int pad,
+					   struct v4l2_mbus_frame_desc *fd)
+{
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+	struct v4l2_mbus_frame_desc csi_fd;
+	struct v4l2_subdev_route *route;
+	struct v4l2_subdev_state *state;
+	int ret;
+
+	if (pad != CSI_FORMATTER_PAD_SOURCE)
+		return -EINVAL;
+
+	ret = v4l2_subdev_call(formatter->csi_sd, pad, get_frame_desc,
+			       formatter->remote_pad, &csi_fd);
+	if (ret)
+		return ret;
+
+	if (csi_fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
+		dev_err(formatter->dev,
+			"Frame descriptor does not describe CSI-2 link\n");
+		return -EINVAL;
+	}
+
+	memset(fd, 0, sizeof(*fd));
+
+	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
+
+	state = v4l2_subdev_lock_and_get_active_state(sd);
+
+	for_each_active_route(&state->routing, route) {
+		struct v4l2_mbus_frame_desc_entry *entry = NULL;
+		unsigned int i;
+
+		if (route->source_pad != pad)
+			continue;
+
+		for (i = 0; i < csi_fd.num_entries; ++i) {
+			if (csi_fd.entry[i].stream == route->sink_stream) {
+				entry = &csi_fd.entry[i];
+				break;
+			}
+		}
+
+		if (!entry) {
+			dev_err(formatter->dev,
+				"Failed to find stream from source frames desc\n");
+			ret = -EPIPE;
+			break;
+		}
+
+		fd->entry[fd->num_entries].stream = route->source_stream;
+		fd->entry[fd->num_entries].flags = entry->flags;
+		fd->entry[fd->num_entries].length = entry->length;
+		fd->entry[fd->num_entries].pixelcode = entry->pixelcode;
+		fd->entry[fd->num_entries].bus.csi2.vc = entry->bus.csi2.vc;
+		fd->entry[fd->num_entries].bus.csi2.dt = entry->bus.csi2.dt;
+
+		fd->num_entries++;
+	}
+
+	v4l2_subdev_unlock_state(state);
+	return ret;
+}
+
+static int formatter_subdev_set_routing(struct v4l2_subdev *sd,
+					struct v4l2_subdev_state *state,
+					enum v4l2_subdev_format_whence which,
+					struct v4l2_subdev_krouting *routing)
+{
+	if (which == V4L2_SUBDEV_FORMAT_ACTIVE &&
+	    media_entity_is_streaming(&sd->entity))
+		return -EBUSY;
+
+	return __formatter_subdev_set_routing(sd, state, routing);
+}
+
+static inline void formatter_write(struct csi_formatter *formatter,
+				   unsigned int reg, unsigned int value)
+{
+	u32 offset = formatter->reg_offset;
+
+	regmap_write(formatter->regs, reg + offset, value);
+}
+
+static u8 get_index_by_dt(u8 data_type)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(formatter_dt_to_index_map); ++i)
+		if (data_type == formatter_dt_to_index_map[i].dtype)
+			break;
+
+	if (i == ARRAY_SIZE(formatter_dt_to_index_map))
+		return formatter_dt_to_index_map[0].index;
+
+	return formatter_dt_to_index_map[i].index;
+}
+
+static int get_vc(struct csi_formatter *formatter, unsigned int stream)
+{
+	struct v4l2_mbus_frame_desc source_fd;
+	struct v4l2_mbus_frame_desc_entry *entry = NULL;
+	unsigned int i;
+	int ret;
+
+	/*
+	 * Return virtual channel 0 as default value when remote subdev
+	 * don't implement .get_frame_desc subdev callback
+	 */
+	ret = v4l2_subdev_call(formatter->csi_sd, pad, get_frame_desc,
+			       formatter->remote_pad, &source_fd);
+	if (ret < 0)
+		return (ret == -ENOIOCTLCMD) ? 0 : ret;
+
+	for (i = 0; i < source_fd.num_entries; ++i) {
+		if (source_fd.entry[i].stream == stream) {
+			entry = &source_fd.entry[i];
+			break;
+		}
+	}
+
+	if (!entry) {
+		dev_err(formatter->dev,
+			"Can't find valid frame desc corresponding to stream %d\n", stream);
+		return -EPIPE;
+	}
+
+	return entry->bus.csi2.vc;
+}
+
+static int csi_formatter_start_stream(struct csi_formatter *formatter,
+				      u64 stream_mask)
+{
+	const struct formatter_pix_format *fmt = formatter->fmt;
+	unsigned int i;
+	u32 val;
+	int vc;
+
+	for (i = 0; i < V4L2_FRAME_DESC_ENTRY_MAX; ++i) {
+		if (stream_mask & BIT(i))
+			break;
+	}
+
+	if (i == V4L2_FRAME_DESC_ENTRY_MAX) {
+		dev_err(formatter->dev, "Stream ID out of range\n");
+		return -EINVAL;
+	}
+
+	val = BIT(get_index_by_dt(fmt->data_type));
+	vc = get_vc(formatter, i);
+
+	if (vc < 0 || vc > CSI_FORMATTER_VC_MAX) {
+		dev_err(formatter->dev, "Invalid virtual channel(%d)\n", vc);
+		return -EINVAL;
+	}
+
+	formatter_write(formatter, CSI_VCx_PIXEL_DATA_TYPE(vc), val);
+
+	return 0;
+}
+
+static int csi_formatter_stop_stream(struct csi_formatter *formatter,
+				     u64 stream_mask)
+{
+	unsigned int i;
+	int vc;
+
+	for (i = 0; i < V4L2_FRAME_DESC_ENTRY_MAX; ++i) {
+		if (stream_mask & BIT(i))
+			break;
+	}
+
+	if (i == V4L2_FRAME_DESC_ENTRY_MAX) {
+		dev_err(formatter->dev, "Stream ID out of range\n");
+		return -EINVAL;
+	}
+
+	vc = get_vc(formatter, i);
+
+	if (vc < 0 || vc > CSI_FORMATTER_VC_MAX) {
+		dev_err(formatter->dev, "Invalid virtual channel(%d)\n", vc);
+		return -EINVAL;
+	}
+
+	formatter_write(formatter, CSI_VCx_PIXEL_DATA_TYPE(vc), 0);
+
+	return 0;
+}
+
+static int formatter_subdev_enable_streams(struct v4l2_subdev *sd,
+					   struct v4l2_subdev_state *state,
+					   u32 pad, u64 streams_mask)
+{
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+	struct device *dev = formatter->dev;
+	u64 sink_streams;
+	int ret;
+
+	sink_streams = v4l2_subdev_state_xlate_streams(state,
+						       CSI_FORMATTER_PAD_SOURCE,
+						       CSI_FORMATTER_PAD_SINK,
+						       &streams_mask);
+	if (!sink_streams || !streams_mask)
+		return -EINVAL;
+
+	dev_dbg(dev, "remote sd: %s pad: %u, sink_stream:0x%llx\n",
+		formatter->csi_sd->name, formatter->remote_pad, sink_streams);
+
+	if (!formatter->csi_sd) {
+		dev_err(dev, "CSI controller don't link with formatter\n");
+		return -EPIPE;
+	}
+
+	if (!formatter->enabled_streams) {
+		ret = pm_runtime_resume_and_get(formatter->dev);
+		if (ret < 0) {
+			dev_err(dev, "Formatter runtime get fail\n");
+			return ret;
+		}
+	}
+
+	ret = csi_formatter_start_stream(formatter, streams_mask);
+	if (ret)
+		goto runtime_put;
+
+	ret = v4l2_subdev_enable_streams(formatter->csi_sd,
+					 formatter->remote_pad,
+					 sink_streams);
+	if (ret)
+		goto stop_stream;
+
+	formatter->enabled_streams |= streams_mask;
+
+	return 0;
+
+stop_stream:
+	csi_formatter_stop_stream(formatter, streams_mask);
+runtime_put:
+	if (!formatter->enabled_streams)
+		pm_runtime_put(formatter->dev);
+	return ret;
+}
+
+static int formatter_subdev_disable_streams(struct v4l2_subdev *sd,
+					    struct v4l2_subdev_state *state,
+					    u32 pad, u64 streams_mask)
+{
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+	u64 sink_streams;
+	int ret;
+
+	sink_streams = v4l2_subdev_state_xlate_streams(state,
+						       CSI_FORMATTER_PAD_SOURCE,
+						       CSI_FORMATTER_PAD_SINK,
+						       &streams_mask);
+	if (!sink_streams || !streams_mask)
+		return -EINVAL;
+
+	ret = v4l2_subdev_disable_streams(formatter->csi_sd, formatter->remote_pad,
+					  sink_streams);
+	if (ret)
+		return ret;
+
+	ret = csi_formatter_stop_stream(formatter, streams_mask);
+	if (ret)
+		return ret;
+
+	formatter->enabled_streams &= ~streams_mask;
+
+	if (!formatter->enabled_streams)
+		pm_runtime_put(formatter->dev);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops formatter_subdev_pad_ops = {
+	.enum_mbus_code		= formatter_subdev_enum_mbus_code,
+	.get_fmt		= v4l2_subdev_get_fmt,
+	.set_fmt		= formatter_subdev_set_fmt,
+	.get_frame_desc		= formatter_subdev_get_frame_desc,
+	.set_routing		= formatter_subdev_set_routing,
+	.enable_streams		= formatter_subdev_enable_streams,
+	.disable_streams	= formatter_subdev_disable_streams,
+};
+
+static const struct v4l2_subdev_ops formatter_subdev_ops = {
+	.pad = &formatter_subdev_pad_ops,
+};
+
+static const struct v4l2_subdev_internal_ops formatter_internal_ops = {
+	.init_state = formatter_subdev_init_state,
+};
+
+/* -----------------------------------------------------------------------------
+ * Media entity operations
+ */
+
+static const struct media_entity_operations formatter_entity_ops = {
+	.link_validate	= v4l2_subdev_link_validate,
+	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
+};
+
+static int csi_formatter_subdev_init(struct csi_formatter *formatter)
+{
+	struct v4l2_subdev *sd = &formatter->sd;
+	int ret;
+
+	v4l2_subdev_init(sd, &formatter_subdev_ops);
+
+	snprintf(sd->name, sizeof(sd->name), "%s", dev_name(formatter->dev));
+	sd->internal_ops = &formatter_internal_ops;
+
+	sd->owner = THIS_MODULE;
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
+		     V4L2_SUBDEV_FL_HAS_EVENTS |
+		     V4L2_SUBDEV_FL_STREAMS;
+	sd->entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
+	sd->entity.ops = &formatter_entity_ops;
+	sd->dev = formatter->dev;
+
+	formatter->pads[CSI_FORMATTER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+	formatter->pads[CSI_FORMATTER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&sd->entity, CSI_FORMATTER_PAD_NUM,
+				     formatter->pads);
+	if (ret) {
+		dev_err(formatter->dev, "Failed to init pads\n");
+		return ret;
+	}
+
+	ret = v4l2_subdev_init_finalize(sd);
+	if (ret)
+		media_entity_cleanup(&sd->entity);
+
+	return ret;
+}
+
+static inline struct csi_formatter *
+notifier_to_formatter(struct v4l2_async_notifier *n)
+{
+	return container_of(n, struct csi_formatter, notifier);
+}
+
+static int csi_formatter_notify_bound(struct v4l2_async_notifier *notifier,
+				      struct v4l2_subdev *sd,
+				      struct v4l2_async_connection *asc)
+{
+	const unsigned int link_flags = MEDIA_LNK_FL_IMMUTABLE
+				      | MEDIA_LNK_FL_ENABLED;
+	struct csi_formatter *formatter = notifier_to_formatter(notifier);
+	struct v4l2_subdev *sdev = &formatter->sd;
+	struct media_pad *sink = &sdev->entity.pads[CSI_FORMATTER_PAD_SINK];
+	struct media_pad *remote_pad;
+	int ret;
+
+	formatter->csi_sd = sd;
+
+	dev_dbg(formatter->dev, "Bound subdev: %s pad\n", sd->name);
+
+	ret = v4l2_create_fwnode_links_to_pad(sd, sink, link_flags);
+	if (ret < 0)
+		return ret;
+
+	remote_pad = media_pad_remote_pad_first(sink);
+	if (!remote_pad) {
+		dev_err(formatter->dev, "Pipe not setup correctly\n");
+		return -EPIPE;
+	}
+	formatter->remote_pad = remote_pad->index;
+
+	return 0;
+}
+
+static const struct v4l2_async_notifier_operations formatter_notify_ops = {
+	.bound = csi_formatter_notify_bound,
+};
+
+static int csi_formatter_async_register(struct csi_formatter *formatter)
+{
+	struct device *dev = formatter->dev;
+	struct v4l2_async_connection *asc;
+	struct fwnode_handle *ep __free(fwnode_handle) = NULL;
+	int ret;
+
+	v4l2_async_subdev_nf_init(&formatter->notifier, &formatter->sd);
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0,
+					     FWNODE_GRAPH_ENDPOINT_NEXT);
+	if (!ep)
+		return -ENOTCONN;
+
+	asc = v4l2_async_nf_add_fwnode_remote(&formatter->notifier, ep,
+					      struct v4l2_async_connection);
+	if (IS_ERR(asc))
+		return PTR_ERR(asc);
+
+	formatter->notifier.ops = &formatter_notify_ops;
+
+	ret = v4l2_async_nf_register(&formatter->notifier);
+	if (ret)
+		return ret;
+
+	return v4l2_async_register_subdev(&formatter->sd);
+}
+
+/* -----------------------------------------------------------------------------
+ * Suspend/resume
+ */
+
+static int csi_formatter_system_suspend(struct device *dev)
+{
+	return pm_runtime_force_suspend(dev);
+}
+
+static int csi_formatter_system_resume(struct device *dev)
+{
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret < 0) {
+		dev_err(dev, "force resume %s failed!\n", dev_name(dev));
+		return ret;
+	}
+
+	return 0;
+}
+
+static int csi_formatter_runtime_suspend(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+
+	clk_disable_unprepare(formatter->clk);
+
+	return 0;
+}
+
+static int csi_formatter_runtime_resume(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+
+	return clk_prepare_enable(formatter->clk);
+}
+
+static const struct dev_pm_ops csi_formatter_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(csi_formatter_system_suspend,
+			    csi_formatter_system_resume)
+	RUNTIME_PM_OPS(csi_formatter_runtime_suspend,
+		       csi_formatter_runtime_resume, NULL)
+};
+
+static int csi_formatter_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct csi_formatter *formatter;
+	u32 val;
+	int ret;
+
+	formatter = devm_kzalloc(dev, sizeof(*formatter), GFP_KERNEL);
+	if (!formatter)
+		return -ENOMEM;
+
+	formatter->dev = dev;
+
+	formatter->regs = syscon_node_to_regmap(dev->parent->of_node);
+	if (IS_ERR(formatter->regs))
+		return dev_err_probe(dev, PTR_ERR(formatter->regs),
+				     "Failed to get csi formatter regmap\n");
+
+	ret = of_property_read_u32(dev->of_node, "reg", &val);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to get csi formatter reg property\n");
+
+	formatter->reg_offset = val;
+
+	formatter->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(formatter->clk))
+		return dev_err_probe(dev, PTR_ERR(formatter->clk),
+				     "Failed to get pixel clock\n");
+
+	ret = csi_formatter_subdev_init(formatter);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "formatter subdev init fail\n");
+
+	/* Initialize formatter pixel format */
+	formatter->fmt = find_csi_format(formatter_default_fmt.code);
+
+	ret = csi_formatter_async_register(formatter);
+	if (ret < 0) {
+		v4l2_subdev_cleanup(&formatter->sd);
+		return dev_err_probe(dev, ret, "Async register failed\n");
+	}
+
+	platform_set_drvdata(pdev, &formatter->sd);
+
+	/* Enable runtime PM. */
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static void csi_formatter_remove(struct platform_device *pdev)
+{
+	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
+	struct csi_formatter *formatter = sd_to_formatter(sd);
+
+	v4l2_async_nf_unregister(&formatter->notifier);
+	v4l2_async_nf_cleanup(&formatter->notifier);
+	v4l2_async_unregister_subdev(&formatter->sd);
+
+	pm_runtime_disable(&pdev->dev);
+	media_entity_cleanup(&formatter->sd.entity);
+	pm_runtime_set_suspended(&pdev->dev);
+}
+
+static const struct of_device_id csi_formatter_of_match[] = {
+	{ .compatible = "fsl,imx9-csi-formatter" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, csi_formatter_of_match);
+
+static struct platform_driver csi_formatter_device_driver = {
+	.driver = {
+		.owner          = THIS_MODULE,
+		.name           = CSI_FORMATTER_DRV_NAME,
+		.of_match_table = csi_formatter_of_match,
+		.pm             = pm_ptr(&csi_formatter_pm_ops),
+	},
+	.probe  = csi_formatter_probe,
+	.remove = csi_formatter_remove,
+};
+
+module_platform_driver(csi_formatter_device_driver);
+
+MODULE_AUTHOR("NXP Semiconductor, Inc.");
+MODULE_DESCRIPTION("NXP i.MX9 CSI Pixel Formatter driver");
+MODULE_LICENSE("GPL");

-- 
2.34.1

On 17/12/2025 07:11, Guoniu Zhou wrote:
> +
> +static const struct v4l2_async_notifier_operations formatter_notify_ops = {
> +	.bound = csi_formatter_notify_bound,
> +};
> +
> +static int csi_formatter_async_register(struct csi_formatter *formatter)
> +{
> +	struct device *dev = formatter->dev;
> +	struct v4l2_async_connection *asc;
> +	struct fwnode_handle *ep __free(fwnode_handle) = NULL;

This is an undesired syntax explicitly documented as one to avoid. You
need here proper assignment, not NULL. Please don't use cleanup.h if you
do not intend to follow it because it does not make the code simpler.

> +	int ret;
> +
> +	v4l2_async_subdev_nf_init(&formatter->notifier, &formatter->sd);
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0,
> +					     FWNODE_GRAPH_ENDPOINT_NEXT);
> +	if (!ep)
> +		return -ENOTCONN;
> +
> +	asc = v4l2_async_nf_add_fwnode_remote(&formatter->notifier, ep,
> +					      struct v4l2_async_connection);
> +	if (IS_ERR(asc))
> +		return PTR_ERR(asc);
> +
> +	formatter->notifier.ops = &formatter_notify_ops;
> +
> +	ret = v4l2_async_nf_register(&formatter->notifier);
> +	if (ret)
> +		return ret;
> +
> +	return v4l2_async_register_subdev(&formatter->sd);
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Suspend/resume
> + */
> +
> +static int csi_formatter_system_suspend(struct device *dev)
> +{
> +	return pm_runtime_force_suspend(dev);
> +}
> +
> +static int csi_formatter_system_resume(struct device *dev)
> +{
> +	int ret;
> +
> +	ret = pm_runtime_force_resume(dev);
> +	if (ret < 0) {
> +		dev_err(dev, "force resume %s failed!\n", dev_name(dev));
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int csi_formatter_runtime_suspend(struct device *dev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct csi_formatter *formatter = sd_to_formatter(sd);
> +
> +	clk_disable_unprepare(formatter->clk);
> +
> +	return 0;
> +}
> +
> +static int csi_formatter_runtime_resume(struct device *dev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct csi_formatter *formatter = sd_to_formatter(sd);
> +
> +	return clk_prepare_enable(formatter->clk);
> +}
> +
> +static const struct dev_pm_ops csi_formatter_pm_ops = {
> +	SYSTEM_SLEEP_PM_OPS(csi_formatter_system_suspend,
> +			    csi_formatter_system_resume)
> +	RUNTIME_PM_OPS(csi_formatter_runtime_suspend,
> +		       csi_formatter_runtime_resume, NULL)
> +};
> +
> +static int csi_formatter_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct csi_formatter *formatter;
> +	u32 val;
> +	int ret;
> +
> +	formatter = devm_kzalloc(dev, sizeof(*formatter), GFP_KERNEL);
> +	if (!formatter)
> +		return -ENOMEM;
> +
> +	formatter->dev = dev;
> +
> +	formatter->regs = syscon_node_to_regmap(dev->parent->of_node);
> +	if (IS_ERR(formatter->regs))
> +		return dev_err_probe(dev, PTR_ERR(formatter->regs),
> +				     "Failed to get csi formatter regmap\n");
> +
> +	ret = of_property_read_u32(dev->of_node, "reg", &val);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "Failed to get csi formatter reg property\n");
> +
> +	formatter->reg_offset = val;
> +
> +	formatter->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(formatter->clk))
> +		return dev_err_probe(dev, PTR_ERR(formatter->clk),
> +				     "Failed to get pixel clock\n");
> +
> +	ret = csi_formatter_subdev_init(formatter);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "formatter subdev init fail\n");
> +
> +	/* Initialize formatter pixel format */
> +	formatter->fmt = find_csi_format(formatter_default_fmt.code);
> +
> +	ret = csi_formatter_async_register(formatter);
> +	if (ret < 0) {
> +		v4l2_subdev_cleanup(&formatter->sd);
> +		return dev_err_probe(dev, ret, "Async register failed\n");
> +	}
> +
> +	platform_set_drvdata(pdev, &formatter->sd);
> +
> +	/* Enable runtime PM. */
> +	pm_runtime_enable(dev);
> +
> +	return 0;
> +}
> +
> +static void csi_formatter_remove(struct platform_device *pdev)
> +{
> +	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
> +	struct csi_formatter *formatter = sd_to_formatter(sd);
> +
> +	v4l2_async_nf_unregister(&formatter->notifier);
> +	v4l2_async_nf_cleanup(&formatter->notifier);
> +	v4l2_async_unregister_subdev(&formatter->sd);
> +
> +	pm_runtime_disable(&pdev->dev);
> +	media_entity_cleanup(&formatter->sd.entity);
> +	pm_runtime_set_suspended(&pdev->dev);
> +}
> +
> +static const struct of_device_id csi_formatter_of_match[] = {
> +	{ .compatible = "fsl,imx9-csi-formatter" },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, csi_formatter_of_match);
> +
> +static struct platform_driver csi_formatter_device_driver = {
> +	.driver = {
> +		.owner          = THIS_MODULE,

Why are you sending us 12 year old code without cleaning it up first?

> +		.name           = CSI_FORMATTER_DRV_NAME,
> +		.of_match_table = csi_formatter_of_match,
> +		.pm             = pm_ptr(&csi_formatter_pm_ops),
> +	},
> +	.probe  = csi_formatter_probe,
> +	.remove = csi_formatter_remove,
> +};
> +
Best regards,
Krzysztof