xref: /linux/drivers/media/platform/raspberrypi/rp1-cfe/cfe.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)

// SPDX-License-Identifier: GPL-2.0-only
/*
 * RP1 Camera Front End Driver
 *
 * Copyright (c) 2021-2024 Raspberry Pi Ltd.
 * Copyright (c) 2023-2024 Ideas on Board Oy
 */

#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/fwnode.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/lcm.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/videodev2.h>

#include <media/v4l2-async.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mc.h>
#include <media/videobuf2-dma-contig.h>

#include <linux/media/raspberrypi/pisp_fe_config.h>
#include <linux/media/raspberrypi/pisp_fe_statistics.h>

#include "cfe-fmts.h"
#include "cfe.h"
#include "csi2.h"
#include "pisp-fe.h"

#define CREATE_TRACE_POINTS
#include "cfe-trace.h"

#define CFE_MODULE_NAME	"rp1-cfe"
#define CFE_VERSION	"1.0"

#define cfe_dbg(cfe, fmt, arg...) dev_dbg(&(cfe)->pdev->dev, fmt, ##arg)
#define cfe_info(cfe, fmt, arg...) dev_info(&(cfe)->pdev->dev, fmt, ##arg)
#define cfe_err(cfe, fmt, arg...) dev_err(&(cfe)->pdev->dev, fmt, ##arg)

/* MIPICFG registers */
#define MIPICFG_CFG		0x004
#define MIPICFG_INTR		0x028
#define MIPICFG_INTE		0x02c
#define MIPICFG_INTF		0x030
#define MIPICFG_INTS		0x034

#define MIPICFG_CFG_SEL_CSI	BIT(0)

#define MIPICFG_INT_CSI_DMA	BIT(0)
#define MIPICFG_INT_CSI_HOST	BIT(2)
#define MIPICFG_INT_PISP_FE	BIT(4)

#define BPL_ALIGNMENT 16
#define MAX_BYTESPERLINE 0xffffff00
#define MAX_BUFFER_SIZE  0xffffff00
/*
 * Max width is therefore determined by the max stride divided by the number of
 * bits per pixel.
 *
 * However, to avoid overflow issues let's use a 16k maximum. This lets us
 * calculate 16k * 16k * 4 with 32bits. If we need higher maximums, a careful
 * review and adjustment of the code is needed so that it will deal with
 * overflows correctly.
 */
#define MAX_WIDTH 16384
#define MAX_HEIGHT MAX_WIDTH
/* Define a nominal minimum image size */
#define MIN_WIDTH 16
#define MIN_HEIGHT 16

#define MIN_META_WIDTH 4
#define MIN_META_HEIGHT 1

const struct v4l2_mbus_framefmt cfe_default_format = {
	.width = 640,
	.height = 480,
	.code = MEDIA_BUS_FMT_SRGGB10_1X10,
	.field = V4L2_FIELD_NONE,
	.colorspace = V4L2_COLORSPACE_RAW,
	.ycbcr_enc = V4L2_YCBCR_ENC_601,
	.quantization = V4L2_QUANTIZATION_FULL_RANGE,
	.xfer_func = V4L2_XFER_FUNC_NONE,
};

enum node_ids {
	/* CSI2 HW output nodes first. */
	CSI2_CH0,
	CSI2_CH1,
	CSI2_CH2,
	CSI2_CH3,
	/* FE only nodes from here on. */
	FE_OUT0,
	FE_OUT1,
	FE_STATS,
	FE_CONFIG,
	NUM_NODES
};

struct node_description {
	enum node_ids id;
	const char *name;
	unsigned int caps;
	unsigned int pad_flags;
	unsigned int link_pad;
};

/* Must match the ordering of enum ids */
static const struct node_description node_desc[NUM_NODES] = {
	[CSI2_CH0] = {
		.name = "csi2-ch0",
		.caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_META_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = CSI2_PAD_FIRST_SOURCE + 0
	},
	/*
	 * At the moment the main userspace component (libcamera) doesn't
	 * support metadata with video nodes that support both video and
	 * metadata. So for the time being this node is set to only support
	 * V4L2_CAP_META_CAPTURE.
	 */
	[CSI2_CH1] = {
		.name = "csi2-ch1",
		.caps = V4L2_CAP_META_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = CSI2_PAD_FIRST_SOURCE + 1
	},
	[CSI2_CH2] = {
		.name = "csi2-ch2",
		.caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_META_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = CSI2_PAD_FIRST_SOURCE + 2
	},
	[CSI2_CH3] = {
		.name = "csi2-ch3",
		.caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_META_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = CSI2_PAD_FIRST_SOURCE + 3
	},
	[FE_OUT0] = {
		.name = "fe-image0",
		.caps = V4L2_CAP_VIDEO_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = FE_OUTPUT0_PAD
	},
	[FE_OUT1] = {
		.name = "fe-image1",
		.caps = V4L2_CAP_VIDEO_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = FE_OUTPUT1_PAD
	},
	[FE_STATS] = {
		.name = "fe-stats",
		.caps = V4L2_CAP_META_CAPTURE,
		.pad_flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = FE_STATS_PAD
	},
	[FE_CONFIG] = {
		.name = "fe-config",
		.caps = V4L2_CAP_META_OUTPUT,
		.pad_flags = MEDIA_PAD_FL_SOURCE | MEDIA_PAD_FL_MUST_CONNECT,
		.link_pad = FE_CONFIG_PAD
	},
};

#define is_fe_node(node) (((node)->id) >= FE_OUT0)
#define is_csi2_node(node) (!is_fe_node(node))

#define node_supports_image_output(node) \
	(node_desc[(node)->id].caps & V4L2_CAP_VIDEO_CAPTURE)
#define node_supports_meta_output(node) \
	(node_desc[(node)->id].caps & V4L2_CAP_META_CAPTURE)
#define node_supports_image_input(node) \
	(node_desc[(node)->id].caps & V4L2_CAP_VIDEO_OUTPUT)
#define node_supports_meta_input(node) \
	(node_desc[(node)->id].caps & V4L2_CAP_META_OUTPUT)
#define node_supports_image(node) \
	(node_supports_image_output(node) || node_supports_image_input(node))
#define node_supports_meta(node) \
	(node_supports_meta_output(node) || node_supports_meta_input(node))

#define is_image_output_node(node) \
	((node)->buffer_queue.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
#define is_image_input_node(node) \
	((node)->buffer_queue.type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
#define is_image_node(node) \
	(is_image_output_node(node) || is_image_input_node(node))
#define is_meta_output_node(node) \
	((node)->buffer_queue.type == V4L2_BUF_TYPE_META_CAPTURE)
#define is_meta_input_node(node) \
	((node)->buffer_queue.type == V4L2_BUF_TYPE_META_OUTPUT)
#define is_meta_node(node) \
	(is_meta_output_node(node) || is_meta_input_node(node))

/* To track state across all nodes. */
#define NODE_REGISTERED		BIT(0)
#define NODE_ENABLED		BIT(1)
#define NODE_STREAMING		BIT(2)
#define FS_INT			BIT(3)
#define FE_INT			BIT(4)
#define NUM_STATES		5

struct cfe_buffer {
	struct vb2_v4l2_buffer vb;
	struct list_head list;
};

struct cfe_config_buffer {
	struct cfe_buffer buf;
	struct pisp_fe_config config;
};

static inline struct cfe_buffer *to_cfe_buffer(struct vb2_buffer *vb)
{
	return container_of(vb, struct cfe_buffer, vb.vb2_buf);
}

static inline
struct cfe_config_buffer *to_cfe_config_buffer(struct cfe_buffer *buf)
{
	return container_of(buf, struct cfe_config_buffer, buf);
}

struct cfe_node {
	/* Node id */
	enum node_ids id;
	/* Pointer pointing to current v4l2_buffer */
	struct cfe_buffer *cur_frm;
	/* Pointer pointing to next v4l2_buffer */
	struct cfe_buffer *next_frm;
	/* Used to store current pixel format */
	struct v4l2_format vid_fmt;
	/* Used to store current meta format */
	struct v4l2_format meta_fmt;
	/* Buffer queue used in video-buf */
	struct vb2_queue buffer_queue;
	/* Queue of filled frames */
	struct list_head dma_queue;
	/* lock used to access this structure */
	struct mutex lock;
	/* Identifies video device for this channel */
	struct video_device video_dev;
	/* Pointer to the parent handle */
	struct cfe_device *cfe;
	/* Media pad for this node */
	struct media_pad pad;
	/* Frame-start counter */
	unsigned int fs_count;
	/* Timestamp of the current buffer */
	u64 ts;
};

struct cfe_device {
	struct dentry *debugfs;
	struct kref kref;

	/* peripheral base address */
	void __iomem *mipi_cfg_base;

	struct clk *clk;

	/* V4l2 device */
	struct v4l2_device v4l2_dev;
	struct media_device mdev;
	struct media_pipeline pipe;

	/* IRQ lock for node state and DMA queues */
	spinlock_t state_lock;
	bool job_ready;
	bool job_queued;

	/* parent device */
	struct platform_device *pdev;
	/* subdevice async Notifier */
	struct v4l2_async_notifier notifier;

	/* Source sub device */
	struct v4l2_subdev *source_sd;
	/* Source subdev's pad */
	u32 source_pad;

	struct cfe_node node[NUM_NODES];
	DECLARE_BITMAP(node_flags, NUM_STATES * NUM_NODES);

	struct csi2_device csi2;
	struct pisp_fe_device fe;

	int fe_csi2_channel;

	/* Mask of enabled streams */
	u64 streams_mask;
};

static inline bool is_fe_enabled(struct cfe_device *cfe)
{
	return cfe->fe_csi2_channel != -1;
}

static inline struct cfe_device *to_cfe_device(struct v4l2_device *v4l2_dev)
{
	return container_of(v4l2_dev, struct cfe_device, v4l2_dev);
}

static inline u32 cfg_reg_read(struct cfe_device *cfe, u32 offset)
{
	return readl(cfe->mipi_cfg_base + offset);
}

static inline void cfg_reg_write(struct cfe_device *cfe, u32 offset, u32 val)
{
	writel(val, cfe->mipi_cfg_base + offset);
}

static bool check_state(struct cfe_device *cfe, unsigned long state,
			unsigned int node_id)
{
	unsigned long bit;

	for_each_set_bit(bit, &state, sizeof(state)) {
		if (!test_bit(bit + (node_id * NUM_STATES), cfe->node_flags))
			return false;
	}

	return true;
}

static void set_state(struct cfe_device *cfe, unsigned long state,
		      unsigned int node_id)
{
	unsigned long bit;

	for_each_set_bit(bit, &state, sizeof(state))
		set_bit(bit + (node_id * NUM_STATES), cfe->node_flags);
}

static void clear_state(struct cfe_device *cfe, unsigned long state,
			unsigned int node_id)
{
	unsigned long bit;

	for_each_set_bit(bit, &state, sizeof(state))
		clear_bit(bit + (node_id * NUM_STATES), cfe->node_flags);
}

static bool test_any_node(struct cfe_device *cfe, unsigned long cond)
{
	for (unsigned int i = 0; i < NUM_NODES; i++) {
		if (check_state(cfe, cond, i))
			return true;
	}

	return false;
}

static bool test_all_nodes(struct cfe_device *cfe, unsigned long precond,
			   unsigned long cond)
{
	for (unsigned int i = 0; i < NUM_NODES; i++) {
		if (check_state(cfe, precond, i)) {
			if (!check_state(cfe, cond, i))
				return false;
		}
	}

	return true;
}

static int mipi_cfg_regs_show(struct seq_file *s, void *data)
{
	struct cfe_device *cfe = s->private;
	int ret;

	ret = pm_runtime_resume_and_get(&cfe->pdev->dev);
	if (ret)
		return ret;

#define DUMP(reg) seq_printf(s, #reg " \t0x%08x\n", cfg_reg_read(cfe, reg))
	DUMP(MIPICFG_CFG);
	DUMP(MIPICFG_INTR);
	DUMP(MIPICFG_INTE);
	DUMP(MIPICFG_INTF);
	DUMP(MIPICFG_INTS);
#undef DUMP

	pm_runtime_put(&cfe->pdev->dev);

	return 0;
}

DEFINE_SHOW_ATTRIBUTE(mipi_cfg_regs);

/* Format setup functions */
const struct cfe_fmt *find_format_by_code(u32 code)
{
	for (unsigned int i = 0; i < ARRAY_SIZE(formats); i++) {
		if (formats[i].code == code)
			return &formats[i];
	}

	return NULL;
}

const struct cfe_fmt *find_format_by_pix(u32 pixelformat)
{
	for (unsigned int i = 0; i < ARRAY_SIZE(formats); i++) {
		if (formats[i].fourcc == pixelformat)
			return &formats[i];
	}

	return NULL;
}

static const struct cfe_fmt *find_format_by_code_and_fourcc(u32 code,
							    u32 fourcc)
{
	for (unsigned int i = 0; i < ARRAY_SIZE(formats); i++) {
		if (formats[i].code == code && formats[i].fourcc == fourcc)
			return &formats[i];
	}

	return NULL;
}

/*
 * Given the mbus code, find the 16 bit remapped code. Returns 0 if no remap
 * possible.
 */
u32 cfe_find_16bit_code(u32 code)
{
	const struct cfe_fmt *cfe_fmt;

	cfe_fmt = find_format_by_code(code);

	if (!cfe_fmt || !cfe_fmt->remap[CFE_REMAP_16BIT])
		return 0;

	cfe_fmt = find_format_by_pix(cfe_fmt->remap[CFE_REMAP_16BIT]);
	if (!cfe_fmt)
		return 0;

	return cfe_fmt->code;
}

/*
 * Given the mbus code, find the 8 bit compressed code. Returns 0 if no remap
 * possible.
 */
u32 cfe_find_compressed_code(u32 code)
{
	const struct cfe_fmt *cfe_fmt;

	cfe_fmt = find_format_by_code(code);

	if (!cfe_fmt || !cfe_fmt->remap[CFE_REMAP_COMPRESSED])
		return 0;

	cfe_fmt = find_format_by_pix(cfe_fmt->remap[CFE_REMAP_COMPRESSED]);
	if (!cfe_fmt)
		return 0;

	return cfe_fmt->code;
}

static void cfe_calc_vid_format_size_bpl(struct cfe_device *cfe,
					 const struct cfe_fmt *fmt,
					 struct v4l2_format *f)
{
	unsigned int min_bytesperline;

	v4l_bound_align_image(&f->fmt.pix.width, MIN_WIDTH, MAX_WIDTH, 2,
			      &f->fmt.pix.height, MIN_HEIGHT, MAX_HEIGHT, 0, 0);

	min_bytesperline =
		ALIGN((f->fmt.pix.width * fmt->depth) >> 3, BPL_ALIGNMENT);

	if (f->fmt.pix.bytesperline > min_bytesperline &&
	    f->fmt.pix.bytesperline <= MAX_BYTESPERLINE)
		f->fmt.pix.bytesperline =
			ALIGN(f->fmt.pix.bytesperline, BPL_ALIGNMENT);
	else
		f->fmt.pix.bytesperline = min_bytesperline;

	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;

	cfe_dbg(cfe, "%s: %p4cc size: %ux%u bpl:%u img_size:%u\n", __func__,
		&f->fmt.pix.pixelformat, f->fmt.pix.width, f->fmt.pix.height,
		f->fmt.pix.bytesperline, f->fmt.pix.sizeimage);
}

static void cfe_calc_meta_format_size_bpl(struct cfe_device *cfe,
					  const struct cfe_fmt *fmt,
					  struct v4l2_format *f)
{
	v4l_bound_align_image(&f->fmt.meta.width, MIN_META_WIDTH, MAX_WIDTH, 2,
			      &f->fmt.meta.height, MIN_META_HEIGHT, MAX_HEIGHT,
			      0, 0);

	f->fmt.meta.bytesperline = (f->fmt.meta.width * fmt->depth) >> 3;
	f->fmt.meta.buffersize = f->fmt.meta.height * f->fmt.pix.bytesperline;

	cfe_dbg(cfe, "%s: %p4cc size: %ux%u bpl:%u buf_size:%u\n", __func__,
		&f->fmt.meta.dataformat, f->fmt.meta.width, f->fmt.meta.height,
		f->fmt.meta.bytesperline, f->fmt.meta.buffersize);
}

static void cfe_schedule_next_csi2_job(struct cfe_device *cfe)
{
	struct cfe_buffer *buf;
	dma_addr_t addr;

	for (unsigned int i = 0; i < CSI2_NUM_CHANNELS; i++) {
		struct cfe_node *node = &cfe->node[i];
		unsigned int stride, size;

		if (!check_state(cfe, NODE_STREAMING, i))
			continue;

		buf = list_first_entry(&node->dma_queue, struct cfe_buffer,
				       list);
		node->next_frm = buf;
		list_del(&buf->list);

		trace_cfe_csi2_schedule(node->id, &buf->vb.vb2_buf);

		if (is_meta_node(node)) {
			size = node->meta_fmt.fmt.meta.buffersize;
			/* We use CSI2_CH_CTRL_PACK_BYTES, so stride == 0 */
			stride = 0;
		} else {
			size = node->vid_fmt.fmt.pix.sizeimage;
			stride = node->vid_fmt.fmt.pix.bytesperline;
		}

		addr = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
		csi2_set_buffer(&cfe->csi2, node->id, addr, stride, size);
	}
}

static void cfe_schedule_next_pisp_job(struct cfe_device *cfe)
{
	struct vb2_buffer *vb2_bufs[FE_NUM_PADS] = { 0 };
	struct cfe_config_buffer *config_buf;
	struct cfe_buffer *buf;

	for (unsigned int i = CSI2_NUM_CHANNELS; i < NUM_NODES; i++) {
		struct cfe_node *node = &cfe->node[i];

		if (!check_state(cfe, NODE_STREAMING, i))
			continue;

		buf = list_first_entry(&node->dma_queue, struct cfe_buffer,
				       list);

		trace_cfe_fe_schedule(node->id, &buf->vb.vb2_buf);

		node->next_frm = buf;
		vb2_bufs[node_desc[i].link_pad] = &buf->vb.vb2_buf;
		list_del(&buf->list);
	}

	config_buf = to_cfe_config_buffer(cfe->node[FE_CONFIG].next_frm);
	pisp_fe_submit_job(&cfe->fe, vb2_bufs, &config_buf->config);
}

static bool cfe_check_job_ready(struct cfe_device *cfe)
{
	for (unsigned int i = 0; i < NUM_NODES; i++) {
		struct cfe_node *node = &cfe->node[i];

		if (!check_state(cfe, NODE_ENABLED, i))
			continue;

		if (list_empty(&node->dma_queue))
			return false;
	}

	return true;
}

static void cfe_prepare_next_job(struct cfe_device *cfe)
{
	trace_cfe_prepare_next_job(is_fe_enabled(cfe));

	cfe->job_queued = true;
	cfe_schedule_next_csi2_job(cfe);
	if (is_fe_enabled(cfe))
		cfe_schedule_next_pisp_job(cfe);

	/* Flag if another job is ready after this. */
	cfe->job_ready = cfe_check_job_ready(cfe);
}

static void cfe_process_buffer_complete(struct cfe_node *node,
					enum vb2_buffer_state state)
{
	trace_cfe_buffer_complete(node->id, &node->cur_frm->vb);

	node->cur_frm->vb.sequence = node->fs_count - 1;
	vb2_buffer_done(&node->cur_frm->vb.vb2_buf, state);
}

static void cfe_queue_event_sof(struct cfe_node *node)
{
	struct v4l2_event event = {
		.type = V4L2_EVENT_FRAME_SYNC,
		.u.frame_sync.frame_sequence = node->fs_count - 1,
	};

	v4l2_event_queue(&node->video_dev, &event);
}

static void cfe_sof_isr(struct cfe_node *node)
{
	struct cfe_device *cfe = node->cfe;
	bool matching_fs = true;

	trace_cfe_frame_start(node->id, node->fs_count);

	/*
	 * If the sensor is producing unexpected frame event ordering over a
	 * sustained period of time, guard against the possibility of coming
	 * here and orphaning the cur_frm if it's not been dequeued already.
	 * Unfortunately, there is not enough hardware state to tell if this
	 * may have occurred.
	 */
	if (WARN(node->cur_frm, "%s: [%s] Orphaned frame at seq %u\n",
		 __func__, node_desc[node->id].name, node->fs_count))
		cfe_process_buffer_complete(node, VB2_BUF_STATE_ERROR);

	node->cur_frm = node->next_frm;
	node->next_frm = NULL;
	node->fs_count++;

	node->ts = ktime_get_ns();
	for (unsigned int i = 0; i < NUM_NODES; i++) {
		if (!check_state(cfe, NODE_STREAMING, i) || i == node->id)
			continue;
		/*
		 * This checks if any other node has seen a FS. If yes, use the
		 * same timestamp, eventually across all node buffers.
		 */
		if (cfe->node[i].fs_count >= node->fs_count)
			node->ts = cfe->node[i].ts;
		/*
		 * This checks if all other node have seen a matching FS. If
		 * yes, we can flag another job to be queued.
		 */
		if (matching_fs && cfe->node[i].fs_count != node->fs_count)
			matching_fs = false;
	}

	if (matching_fs)
		cfe->job_queued = false;

	if (node->cur_frm)
		node->cur_frm->vb.vb2_buf.timestamp = node->ts;

	set_state(cfe, FS_INT, node->id);
	clear_state(cfe, FE_INT, node->id);

	if (is_image_output_node(node))
		cfe_queue_event_sof(node);
}

static void cfe_eof_isr(struct cfe_node *node)
{
	struct cfe_device *cfe = node->cfe;

	trace_cfe_frame_end(node->id, node->fs_count - 1);

	if (node->cur_frm)
		cfe_process_buffer_complete(node, VB2_BUF_STATE_DONE);

	node->cur_frm = NULL;
	set_state(cfe, FE_INT, node->id);
	clear_state(cfe, FS_INT, node->id);
}

static irqreturn_t cfe_isr(int irq, void *dev)
{
	struct cfe_device *cfe = dev;
	bool sof[NUM_NODES] = { 0 }, eof[NUM_NODES] = { 0 };
	u32 sts;

	sts = cfg_reg_read(cfe, MIPICFG_INTS);

	if (sts & MIPICFG_INT_CSI_DMA)
		csi2_isr(&cfe->csi2, sof, eof);

	if (sts & MIPICFG_INT_PISP_FE)
		pisp_fe_isr(&cfe->fe, sof + CSI2_NUM_CHANNELS,
			    eof + CSI2_NUM_CHANNELS);

	spin_lock(&cfe->state_lock);

	for (unsigned int i = 0; i < NUM_NODES; i++) {
		struct cfe_node *node = &cfe->node[i];

		/*
		 * The check_state(NODE_STREAMING) is to ensure we do not loop
		 * over the CSI2_CHx nodes when the FE is active since they
		 * generate interrupts even though the node is not streaming.
		 */
		if (!check_state(cfe, NODE_STREAMING, i) || !(sof[i] || eof[i]))
			continue;

		/*
		 * There are 3 cases where we could get FS + FE_ACK at
		 * the same time:
		 * 1) FE of the current frame, and FS of the next frame.
		 * 2) FS + FE of the same frame.
		 * 3) FE of the current frame, and FS + FE of the next
		 *    frame. To handle this, see the sof handler below.
		 *
		 * (1) is handled implicitly by the ordering of the FE and FS
		 * handlers below.
		 */
		if (eof[i]) {
			/*
			 * The condition below tests for (2). Run the FS handler
			 * first before the FE handler, both for the current
			 * frame.
			 */
			if (sof[i] && !check_state(cfe, FS_INT, i)) {
				cfe_sof_isr(node);
				sof[i] = false;
			}

			cfe_eof_isr(node);
		}

		if (sof[i]) {
			/*
			 * The condition below tests for (3). In such cases, we
			 * come in here with FS flag set in the node state from
			 * the previous frame since it only gets cleared in
			 * cfe_eof_isr(). Handle the FE for the previous
			 * frame first before the FS handler for the current
			 * frame.
			 */
			if (check_state(cfe, FS_INT, node->id) &&
			    !check_state(cfe, FE_INT, node->id)) {
				cfe_dbg(cfe, "%s: [%s] Handling missing previous FE interrupt\n",
					__func__, node_desc[node->id].name);
				cfe_eof_isr(node);
			}

			cfe_sof_isr(node);
		}

		if (!cfe->job_queued && cfe->job_ready)
			cfe_prepare_next_job(cfe);
	}

	spin_unlock(&cfe->state_lock);

	return IRQ_HANDLED;
}

/*
 * Stream helpers
 */

static int cfe_get_vc_dt_fallback(struct cfe_device *cfe, u8 *vc, u8 *dt)
{
	struct v4l2_subdev_state *state;
	struct v4l2_mbus_framefmt *fmt;
	const struct cfe_fmt *cfe_fmt;

	state = v4l2_subdev_get_locked_active_state(&cfe->csi2.sd);

	fmt = v4l2_subdev_state_get_format(state, CSI2_PAD_SINK, 0);
	if (!fmt)
		return -EINVAL;

	cfe_fmt = find_format_by_code(fmt->code);
	if (!cfe_fmt)
		return -EINVAL;

	*vc = 0;
	*dt = cfe_fmt->csi_dt;

	return 0;
}

static int cfe_get_vc_dt(struct cfe_device *cfe, unsigned int channel, u8 *vc,
			 u8 *dt)
{
	struct v4l2_mbus_frame_desc remote_desc;
	struct v4l2_subdev_state *state;
	u32 sink_stream;
	unsigned int i;
	int ret;

	state = v4l2_subdev_get_locked_active_state(&cfe->csi2.sd);

	ret = v4l2_subdev_routing_find_opposite_end(&state->routing,
		CSI2_PAD_FIRST_SOURCE + channel, 0, NULL, &sink_stream);
	if (ret)
		return ret;

	ret = v4l2_subdev_call(cfe->source_sd, pad, get_frame_desc,
			       cfe->source_pad, &remote_desc);
	if (ret == -ENOIOCTLCMD) {
		cfe_dbg(cfe, "source does not support get_frame_desc, use fallback\n");
		return cfe_get_vc_dt_fallback(cfe, vc, dt);
	} else if (ret) {
		cfe_err(cfe, "Failed to get frame descriptor\n");
		return ret;
	}

	if (remote_desc.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
		cfe_err(cfe, "Frame descriptor does not describe CSI-2 link");
		return -EINVAL;
	}

	for (i = 0; i < remote_desc.num_entries; i++) {
		if (remote_desc.entry[i].stream == sink_stream)
			break;
	}

	if (i == remote_desc.num_entries) {
		cfe_err(cfe, "Stream %u not found in remote frame desc\n",
			sink_stream);
		return -EINVAL;
	}

	*vc = remote_desc.entry[i].bus.csi2.vc;
	*dt = remote_desc.entry[i].bus.csi2.dt;

	return 0;
}

static int cfe_start_channel(struct cfe_node *node)
{
	struct cfe_device *cfe = node->cfe;
	struct v4l2_subdev_state *state;
	struct v4l2_mbus_framefmt *source_fmt;
	const struct cfe_fmt *fmt;
	unsigned long flags;
	bool start_fe;
	int ret;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	start_fe = is_fe_enabled(cfe) &&
		   test_all_nodes(cfe, NODE_ENABLED, NODE_STREAMING);

	state = v4l2_subdev_get_locked_active_state(&cfe->csi2.sd);

	if (start_fe) {
		unsigned int width, height;
		u8 vc, dt;

		cfe_dbg(cfe, "%s: %s using csi2 channel %d\n", __func__,
			node_desc[FE_OUT0].name, cfe->fe_csi2_channel);

		ret = cfe_get_vc_dt(cfe, cfe->fe_csi2_channel, &vc, &dt);
		if (ret)
			return ret;

		source_fmt = v4l2_subdev_state_get_format(state,
			node_desc[cfe->fe_csi2_channel].link_pad);
		fmt = find_format_by_code(source_fmt->code);

		width = source_fmt->width;
		height = source_fmt->height;

		/* Must have a valid CSI2 datatype. */
		WARN_ON(!fmt->csi_dt);

		/*
		 * Start the associated CSI2 Channel as well.
		 *
		 * Must write to the ADDR register to latch the ctrl values
		 * even if we are connected to the front end. Once running,
		 * this is handled by the CSI2 AUTO_ARM mode.
		 */
		csi2_start_channel(&cfe->csi2, cfe->fe_csi2_channel,
				   CSI2_MODE_FE_STREAMING,
				   true, false, width, height, vc, dt);
		csi2_set_buffer(&cfe->csi2, cfe->fe_csi2_channel, 0, 0, -1);
		pisp_fe_start(&cfe->fe);
	}

	if (is_csi2_node(node)) {
		unsigned int width = 0, height = 0;
		u8 vc, dt;

		ret = cfe_get_vc_dt(cfe, node->id, &vc, &dt);
		if (ret) {
			if (start_fe) {
				csi2_stop_channel(&cfe->csi2,
						  cfe->fe_csi2_channel);
				pisp_fe_stop(&cfe->fe);
			}

			return ret;
		}

		u32 mode = CSI2_MODE_NORMAL;

		source_fmt = v4l2_subdev_state_get_format(state,
			node_desc[node->id].link_pad);
		fmt = find_format_by_code(source_fmt->code);

		/* Must have a valid CSI2 datatype. */
		WARN_ON(!fmt->csi_dt);

		if (is_image_output_node(node)) {
			u32  pixfmt;

			width = source_fmt->width;
			height = source_fmt->height;

			pixfmt = node->vid_fmt.fmt.pix.pixelformat;

			if (pixfmt == fmt->remap[CFE_REMAP_16BIT]) {
				mode = CSI2_MODE_REMAP;
			} else if (pixfmt == fmt->remap[CFE_REMAP_COMPRESSED]) {
				mode = CSI2_MODE_COMPRESSED;
				csi2_set_compression(&cfe->csi2, node->id,
						     CSI2_COMPRESSION_DELTA, 0,
						     0);
			}
		}
		/* Unconditionally start this CSI2 channel. */
		csi2_start_channel(&cfe->csi2, node->id,
				   mode,
				   /* Auto arm */
				   false,
				   /* Pack bytes */
				   is_meta_node(node) ? true : false,
				   width, height, vc, dt);
	}

	spin_lock_irqsave(&cfe->state_lock, flags);
	if (cfe->job_ready && test_all_nodes(cfe, NODE_ENABLED, NODE_STREAMING))
		cfe_prepare_next_job(cfe);
	spin_unlock_irqrestore(&cfe->state_lock, flags);

	return 0;
}

static void cfe_stop_channel(struct cfe_node *node, bool fe_stop)
{
	struct cfe_device *cfe = node->cfe;

	cfe_dbg(cfe, "%s: [%s] fe_stop %u\n", __func__,
		node_desc[node->id].name, fe_stop);

	if (fe_stop) {
		csi2_stop_channel(&cfe->csi2, cfe->fe_csi2_channel);
		pisp_fe_stop(&cfe->fe);
	}

	if (is_csi2_node(node))
		csi2_stop_channel(&cfe->csi2, node->id);
}

static void cfe_return_buffers(struct cfe_node *node,
			       enum vb2_buffer_state state)
{
	struct cfe_device *cfe = node->cfe;
	struct cfe_buffer *buf, *tmp;
	unsigned long flags;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	spin_lock_irqsave(&cfe->state_lock, flags);
	list_for_each_entry_safe(buf, tmp, &node->dma_queue, list) {
		list_del(&buf->list);
		trace_cfe_return_buffer(node->id, buf->vb.vb2_buf.index, 2);
		vb2_buffer_done(&buf->vb.vb2_buf, state);
	}

	if (node->cur_frm) {
		trace_cfe_return_buffer(node->id,
					node->cur_frm->vb.vb2_buf.index, 0);
		vb2_buffer_done(&node->cur_frm->vb.vb2_buf, state);
	}
	if (node->next_frm && node->cur_frm != node->next_frm) {
		trace_cfe_return_buffer(node->id,
					node->next_frm->vb.vb2_buf.index, 1);
		vb2_buffer_done(&node->next_frm->vb.vb2_buf, state);
	}

	node->cur_frm = NULL;
	node->next_frm = NULL;
	spin_unlock_irqrestore(&cfe->state_lock, flags);
}

/*
 * vb2 ops
 */

static int cfe_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
			   unsigned int *nplanes, unsigned int sizes[],
			   struct device *alloc_devs[])
{
	struct cfe_node *node = vb2_get_drv_priv(vq);
	struct cfe_device *cfe = node->cfe;
	unsigned int size = is_image_node(node) ?
				    node->vid_fmt.fmt.pix.sizeimage :
				    node->meta_fmt.fmt.meta.buffersize;

	cfe_dbg(cfe, "%s: [%s] type:%u\n", __func__, node_desc[node->id].name,
		node->buffer_queue.type);

	if (vq->max_num_buffers + *nbuffers < 3)
		*nbuffers = 3 - vq->max_num_buffers;

	if (*nplanes) {
		if (sizes[0] < size) {
			cfe_err(cfe, "sizes[0] %i < size %u\n", sizes[0], size);
			return -EINVAL;
		}
		size = sizes[0];
	}

	*nplanes = 1;
	sizes[0] = size;

	return 0;
}

static int cfe_buffer_prepare(struct vb2_buffer *vb)
{
	struct cfe_node *node = vb2_get_drv_priv(vb->vb2_queue);
	struct cfe_device *cfe = node->cfe;
	struct cfe_buffer *buf = to_cfe_buffer(vb);
	unsigned long size;

	trace_cfe_buffer_prepare(node->id, vb);

	size = is_image_node(node) ? node->vid_fmt.fmt.pix.sizeimage :
				     node->meta_fmt.fmt.meta.buffersize;
	if (vb2_plane_size(vb, 0) < size) {
		cfe_err(cfe, "data will not fit into plane (%lu < %lu)\n",
			vb2_plane_size(vb, 0), size);
		return -EINVAL;
	}

	vb2_set_plane_payload(&buf->vb.vb2_buf, 0, size);

	if (node->id == FE_CONFIG) {
		struct cfe_config_buffer *b = to_cfe_config_buffer(buf);
		void *addr = vb2_plane_vaddr(vb, 0);

		memcpy(&b->config, addr, sizeof(struct pisp_fe_config));
		return pisp_fe_validate_config(&cfe->fe, &b->config,
					       &cfe->node[FE_OUT0].vid_fmt,
					       &cfe->node[FE_OUT1].vid_fmt);
	}

	return 0;
}

static void cfe_buffer_queue(struct vb2_buffer *vb)
{
	struct cfe_node *node = vb2_get_drv_priv(vb->vb2_queue);
	struct cfe_device *cfe = node->cfe;
	struct cfe_buffer *buf = to_cfe_buffer(vb);
	unsigned long flags;
	bool schedule_now;

	spin_lock_irqsave(&cfe->state_lock, flags);

	list_add_tail(&buf->list, &node->dma_queue);

	if (!cfe->job_ready)
		cfe->job_ready = cfe_check_job_ready(cfe);

	schedule_now = !cfe->job_queued && cfe->job_ready &&
		       test_all_nodes(cfe, NODE_ENABLED, NODE_STREAMING);

	trace_cfe_buffer_queue(node->id, vb, schedule_now);

	if (schedule_now)
		cfe_prepare_next_job(cfe);

	spin_unlock_irqrestore(&cfe->state_lock, flags);
}

static s64 cfe_get_source_link_freq(struct cfe_device *cfe)
{
	struct v4l2_subdev_state *state;
	s64 link_freq;
	u32 bpp;

	state = v4l2_subdev_get_locked_active_state(&cfe->csi2.sd);

	/*
	 * v4l2_get_link_freq() uses V4L2_CID_LINK_FREQ first, and falls back
	 * to V4L2_CID_PIXEL_RATE if V4L2_CID_LINK_FREQ is not available.
	 *
	 * With multistream input there is no single pixel rate, and thus we
	 * cannot use V4L2_CID_PIXEL_RATE, so we pass 0 as the bpp which
	 * causes v4l2_get_link_freq() to return an error if it falls back to
	 * V4L2_CID_PIXEL_RATE.
	 */

	if (state->routing.num_routes == 1) {
		struct v4l2_subdev_route *route = &state->routing.routes[0];
		struct v4l2_mbus_framefmt *source_fmt;
		const struct cfe_fmt *fmt;

		source_fmt = v4l2_subdev_state_get_format(state,
							  route->sink_pad,
							  route->sink_stream);

		fmt = find_format_by_code(source_fmt->code);
		if (!fmt)
			return -EINVAL;

		bpp = fmt->depth;
	} else {
		bpp = 0;
	}

	link_freq = v4l2_get_link_freq(cfe->source_sd->ctrl_handler, bpp,
				       2 * cfe->csi2.dphy.active_lanes);
	if (link_freq < 0)
		cfe_err(cfe, "failed to get link freq for subdev '%s'\n",
			cfe->source_sd->name);

	return link_freq;
}

static int cfe_start_streaming(struct vb2_queue *vq, unsigned int count)
{
	struct v4l2_mbus_config mbus_config = { 0 };
	struct cfe_node *node = vb2_get_drv_priv(vq);
	struct cfe_device *cfe = node->cfe;
	struct v4l2_subdev_state *state;
	struct v4l2_subdev_route *route;
	s64 link_freq;
	int ret;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	if (!check_state(cfe, NODE_ENABLED, node->id)) {
		cfe_err(cfe, "%s node link is not enabled.\n",
			node_desc[node->id].name);
		ret = -EINVAL;
		goto err_streaming;
	}

	ret = pm_runtime_resume_and_get(&cfe->pdev->dev);
	if (ret < 0) {
		cfe_err(cfe, "pm_runtime_resume_and_get failed\n");
		goto err_streaming;
	}

	/* When using the Frontend, we must enable the FE_CONFIG node. */
	if (is_fe_enabled(cfe) &&
	    !check_state(cfe, NODE_ENABLED, cfe->node[FE_CONFIG].id)) {
		cfe_err(cfe, "FE enabled, but FE_CONFIG node is not\n");
		ret = -EINVAL;
		goto err_pm_put;
	}

	ret = media_pipeline_start(&node->pad, &cfe->pipe);
	if (ret < 0) {
		cfe_err(cfe, "Failed to start media pipeline: %d\n", ret);
		goto err_pm_put;
	}

	state = v4l2_subdev_lock_and_get_active_state(&cfe->csi2.sd);

	clear_state(cfe, FS_INT | FE_INT, node->id);
	set_state(cfe, NODE_STREAMING, node->id);
	node->fs_count = 0;

	ret = cfe_start_channel(node);
	if (ret)
		goto err_unlock_state;

	if (!test_all_nodes(cfe, NODE_ENABLED, NODE_STREAMING)) {
		cfe_dbg(cfe, "Streaming on hold, as all nodes are not set to streaming yet\n");
		v4l2_subdev_unlock_state(state);
		return 0;
	}

	cfg_reg_write(cfe, MIPICFG_CFG, MIPICFG_CFG_SEL_CSI);
	cfg_reg_write(cfe, MIPICFG_INTE,
		      MIPICFG_INT_CSI_DMA | MIPICFG_INT_PISP_FE);

	ret = v4l2_subdev_call(cfe->source_sd, pad, get_mbus_config, 0,
			       &mbus_config);
	if (ret < 0 && ret != -ENOIOCTLCMD) {
		cfe_err(cfe, "g_mbus_config failed\n");
		goto err_clear_inte;
	}

	cfe->csi2.dphy.active_lanes = mbus_config.bus.mipi_csi2.num_data_lanes;
	if (!cfe->csi2.dphy.active_lanes)
		cfe->csi2.dphy.active_lanes = cfe->csi2.dphy.max_lanes;
	if (cfe->csi2.dphy.active_lanes > cfe->csi2.dphy.max_lanes) {
		cfe_err(cfe, "Device has requested %u data lanes, which is >%u configured in DT\n",
			cfe->csi2.dphy.active_lanes, cfe->csi2.dphy.max_lanes);
		ret = -EINVAL;
		goto err_clear_inte;
	}

	link_freq = cfe_get_source_link_freq(cfe);
	if (link_freq < 0)
		goto err_clear_inte;

	cfe->csi2.dphy.dphy_rate = div_s64(link_freq * 2, 1000000);
	csi2_open_rx(&cfe->csi2);

	cfe->streams_mask = 0;

	for_each_active_route(&state->routing, route)
		cfe->streams_mask |= BIT_ULL(route->sink_stream);

	ret = v4l2_subdev_enable_streams(cfe->source_sd, cfe->source_pad,
					 cfe->streams_mask);
	if (ret) {
		cfe_err(cfe, "stream on failed in subdev\n");
		goto err_disable_cfe;
	}

	cfe_dbg(cfe, "Streaming enabled\n");

	v4l2_subdev_unlock_state(state);

	return 0;

err_disable_cfe:
	csi2_close_rx(&cfe->csi2);
err_clear_inte:
	cfg_reg_write(cfe, MIPICFG_INTE, 0);

	cfe_stop_channel(node,
			 is_fe_enabled(cfe) && test_all_nodes(cfe, NODE_ENABLED,
							      NODE_STREAMING));
err_unlock_state:
	v4l2_subdev_unlock_state(state);
	media_pipeline_stop(&node->pad);
err_pm_put:
	pm_runtime_put(&cfe->pdev->dev);
err_streaming:
	cfe_return_buffers(node, VB2_BUF_STATE_QUEUED);
	clear_state(cfe, NODE_STREAMING, node->id);

	return ret;
}

static void cfe_stop_streaming(struct vb2_queue *vq)
{
	struct cfe_node *node = vb2_get_drv_priv(vq);
	struct cfe_device *cfe = node->cfe;
	unsigned long flags;
	bool fe_stop;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	spin_lock_irqsave(&cfe->state_lock, flags);
	fe_stop = is_fe_enabled(cfe) &&
		  test_all_nodes(cfe, NODE_ENABLED, NODE_STREAMING);

	cfe->job_ready = false;
	clear_state(cfe, NODE_STREAMING, node->id);
	spin_unlock_irqrestore(&cfe->state_lock, flags);

	cfe_stop_channel(node, fe_stop);

	if (!test_any_node(cfe, NODE_STREAMING)) {
		struct v4l2_subdev_state *state;
		int ret;

		state = v4l2_subdev_lock_and_get_active_state(&cfe->csi2.sd);

		ret = v4l2_subdev_disable_streams(cfe->source_sd,
						  cfe->source_pad,
						  cfe->streams_mask);
		if (ret)
			cfe_err(cfe, "stream disable failed in subdev\n");

		v4l2_subdev_unlock_state(state);

		csi2_close_rx(&cfe->csi2);

		cfg_reg_write(cfe, MIPICFG_INTE, 0);

		cfe_dbg(cfe, "%s: Streaming disabled\n", __func__);
	}

	media_pipeline_stop(&node->pad);

	/* Clear all queued buffers for the node */
	cfe_return_buffers(node, VB2_BUF_STATE_ERROR);

	pm_runtime_put(&cfe->pdev->dev);
}

static const struct vb2_ops cfe_video_qops = {
	.wait_prepare = vb2_ops_wait_prepare,
	.wait_finish = vb2_ops_wait_finish,
	.queue_setup = cfe_queue_setup,
	.buf_prepare = cfe_buffer_prepare,
	.buf_queue = cfe_buffer_queue,
	.start_streaming = cfe_start_streaming,
	.stop_streaming = cfe_stop_streaming,
};

/*
 * v4l2 ioctl ops
 */

static int cfe_querycap(struct file *file, void *priv,
			struct v4l2_capability *cap)
{
	strscpy(cap->driver, CFE_MODULE_NAME, sizeof(cap->driver));
	strscpy(cap->card, CFE_MODULE_NAME, sizeof(cap->card));

	cap->capabilities |= V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_META_CAPTURE |
			     V4L2_CAP_META_OUTPUT;

	return 0;
}

static int cfe_enum_fmt_vid_cap(struct file *file, void *priv,
				struct v4l2_fmtdesc *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;
	unsigned int i, j;

	if (!node_supports_image_output(node))
		return -EINVAL;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	for (i = 0, j = 0; i < ARRAY_SIZE(formats); i++) {
		if (f->mbus_code && formats[i].code != f->mbus_code)
			continue;

		if (formats[i].flags & CFE_FORMAT_FLAG_META_OUT ||
		    formats[i].flags & CFE_FORMAT_FLAG_META_CAP)
			continue;

		if (is_fe_node(node) &&
		    !(formats[i].flags & CFE_FORMAT_FLAG_FE_OUT))
			continue;

		if (j == f->index) {
			f->pixelformat = formats[i].fourcc;
			f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
			return 0;
		}
		j++;
	}

	return -EINVAL;
}

static int cfe_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
{
	struct cfe_node *node = video_drvdata(file);

	if (!node_supports_image(node))
		return -EINVAL;

	*f = node->vid_fmt;

	return 0;
}

static int cfe_validate_fmt_vid_cap(struct cfe_node *node,
				    struct v4l2_format *f)
{
	struct cfe_device *cfe = node->cfe;
	const struct cfe_fmt *fmt;

	cfe_dbg(cfe, "%s: [%s] %ux%u, V4L2 pix %p4cc\n", __func__,
		node_desc[node->id].name, f->fmt.pix.width, f->fmt.pix.height,
		&f->fmt.pix.pixelformat);

	if (!node_supports_image_output(node))
		return -EINVAL;

	/*
	 * Default to a format that works for both CSI2 and FE.
	 */
	fmt = find_format_by_pix(f->fmt.pix.pixelformat);
	if (!fmt)
		fmt = find_format_by_code(MEDIA_BUS_FMT_SBGGR10_1X10);

	f->fmt.pix.pixelformat = fmt->fourcc;

	if (is_fe_node(node) && fmt->remap[CFE_REMAP_16BIT]) {
		f->fmt.pix.pixelformat = fmt->remap[CFE_REMAP_16BIT];
		fmt = find_format_by_pix(f->fmt.pix.pixelformat);
	}

	f->fmt.pix.field = V4L2_FIELD_NONE;

	cfe_calc_vid_format_size_bpl(cfe, fmt, f);

	return 0;
}

static int cfe_s_fmt_vid_cap(struct file *file, void *priv,
			     struct v4l2_format *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;
	struct vb2_queue *q = &node->buffer_queue;
	int ret;

	if (vb2_is_busy(q))
		return -EBUSY;

	ret = cfe_validate_fmt_vid_cap(node, f);
	if (ret)
		return ret;

	node->vid_fmt = *f;

	cfe_dbg(cfe, "%s: Set %ux%u, V4L2 pix %p4cc\n", __func__,
		node->vid_fmt.fmt.pix.width, node->vid_fmt.fmt.pix.height,
		&node->vid_fmt.fmt.pix.pixelformat);

	return 0;
}

static int cfe_try_fmt_vid_cap(struct file *file, void *priv,
			       struct v4l2_format *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	return cfe_validate_fmt_vid_cap(node, f);
}

static int cfe_enum_fmt_meta(struct file *file, void *priv,
			     struct v4l2_fmtdesc *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	if (!node_supports_meta(node))
		return -EINVAL;

	switch (node->id) {
	case CSI2_CH0...CSI2_CH3:
		f->flags = V4L2_FMT_FLAG_META_LINE_BASED;

		switch (f->index) {
		case 0:
			f->pixelformat = V4L2_META_FMT_GENERIC_8;
			return 0;
		case 1:
			f->pixelformat = V4L2_META_FMT_GENERIC_CSI2_10;
			return 0;
		case 2:
			f->pixelformat = V4L2_META_FMT_GENERIC_CSI2_12;
			return 0;
		default:
			return -EINVAL;
		}
	default:
		break;
	}

	if (f->index != 0)
		return -EINVAL;

	switch (node->id) {
	case FE_STATS:
		f->pixelformat = V4L2_META_FMT_RPI_FE_STATS;
		return 0;
	case FE_CONFIG:
		f->pixelformat = V4L2_META_FMT_RPI_FE_CFG;
		return 0;
	default:
		return -EINVAL;
	}
}

static int cfe_validate_fmt_meta(struct cfe_node *node, struct v4l2_format *f)
{
	struct cfe_device *cfe = node->cfe;
	const struct cfe_fmt *fmt;

	switch (node->id) {
	case CSI2_CH0...CSI2_CH3:
		cfe_dbg(cfe, "%s: [%s] %ux%u, V4L2 meta %p4cc\n", __func__,
			node_desc[node->id].name, f->fmt.meta.width,
			f->fmt.meta.height, &f->fmt.meta.dataformat);
		break;
	case FE_STATS:
	case FE_CONFIG:
		cfe_dbg(cfe, "%s: [%s] %u bytes, V4L2 meta %p4cc\n", __func__,
			node_desc[node->id].name, f->fmt.meta.buffersize,
			&f->fmt.meta.dataformat);
		break;
	default:
		return -EINVAL;
	}

	if (!node_supports_meta(node))
		return -EINVAL;

	switch (node->id) {
	case CSI2_CH0...CSI2_CH3:
		fmt = find_format_by_pix(f->fmt.meta.dataformat);
		if (!fmt || !(fmt->flags & CFE_FORMAT_FLAG_META_CAP))
			fmt = find_format_by_pix(V4L2_META_FMT_GENERIC_CSI2_10);

		f->fmt.meta.dataformat = fmt->fourcc;

		cfe_calc_meta_format_size_bpl(cfe, fmt, f);

		return 0;
	case FE_STATS:
		f->fmt.meta.dataformat = V4L2_META_FMT_RPI_FE_STATS;
		f->fmt.meta.buffersize = sizeof(struct pisp_statistics);
		return 0;
	case FE_CONFIG:
		f->fmt.meta.dataformat = V4L2_META_FMT_RPI_FE_CFG;
		f->fmt.meta.buffersize = sizeof(struct pisp_fe_config);
		return 0;
	default:
		return -EINVAL;
	}
}

static int cfe_g_fmt_meta(struct file *file, void *priv, struct v4l2_format *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	if (!node_supports_meta(node))
		return -EINVAL;

	*f = node->meta_fmt;

	return 0;
}

static int cfe_s_fmt_meta(struct file *file, void *priv, struct v4l2_format *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;
	struct vb2_queue *q = &node->buffer_queue;
	int ret;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);

	if (vb2_is_busy(q))
		return -EBUSY;

	if (!node_supports_meta(node))
		return -EINVAL;

	ret = cfe_validate_fmt_meta(node, f);
	if (ret)
		return ret;

	node->meta_fmt = *f;

	cfe_dbg(cfe, "%s: Set %p4cc\n", __func__,
		&node->meta_fmt.fmt.meta.dataformat);

	return 0;
}

static int cfe_try_fmt_meta(struct file *file, void *priv,
			    struct v4l2_format *f)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;

	cfe_dbg(cfe, "%s: [%s]\n", __func__, node_desc[node->id].name);
	return cfe_validate_fmt_meta(node, f);
}

static int cfe_enum_framesizes(struct file *file, void *priv,
			       struct v4l2_frmsizeenum *fsize)
{
	struct cfe_node *node = video_drvdata(file);
	struct cfe_device *cfe = node->cfe;
	const struct cfe_fmt *fmt;

	cfe_dbg(cfe, "%s [%s]\n", __func__, node_desc[node->id].name);

	if (fsize->index > 0)
		return -EINVAL;

	/* check for valid format */
	fmt = find_format_by_pix(fsize->pixel_format);
	if (!fmt) {
		cfe_dbg(cfe, "Invalid pixel code: %x\n", fsize->pixel_format);
		return -EINVAL;
	}

	/* TODO: Do we have limits on the step_width? */

	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
	fsize->stepwise.min_width = MIN_WIDTH;
	fsize->stepwise.max_width = MAX_WIDTH;
	fsize->stepwise.step_width = 2;
	fsize->stepwise.min_height = MIN_HEIGHT;
	fsize->stepwise.max_height = MAX_HEIGHT;
	fsize->stepwise.step_height = 1;

	return 0;
}

static int cfe_vb2_ioctl_reqbufs(struct file *file, void *priv,
				 struct v4l2_requestbuffers *p)
{
	struct video_device *vdev = video_devdata(file);
	struct cfe_node *node = video_get_drvdata(vdev);
	struct cfe_device *cfe = node->cfe;
	int ret;

	cfe_dbg(cfe, "%s: [%s] type:%u\n", __func__, node_desc[node->id].name,
		p->type);

	if (p->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
	    p->type != V4L2_BUF_TYPE_META_CAPTURE &&
	    p->type != V4L2_BUF_TYPE_META_OUTPUT)
		return -EINVAL;

	ret = vb2_queue_change_type(vdev->queue, p->type);
	if (ret)
		return ret;

	return vb2_ioctl_reqbufs(file, priv, p);
}

static int cfe_vb2_ioctl_create_bufs(struct file *file, void *priv,
				     struct v4l2_create_buffers *p)
{
	struct video_device *vdev = video_devdata(file);
	struct cfe_node *node = video_get_drvdata(vdev);
	struct cfe_device *cfe = node->cfe;
	int ret;

	cfe_dbg(cfe, "%s: [%s] type:%u\n", __func__, node_desc[node->id].name,
		p->format.type);

	if (p->format.type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
	    p->format.type != V4L2_BUF_TYPE_META_CAPTURE &&
	    p->format.type != V4L2_BUF_TYPE_META_OUTPUT)
		return -EINVAL;

	ret = vb2_queue_change_type(vdev->queue, p->format.type);
	if (ret)
		return ret;

	return vb2_ioctl_create_bufs(file, priv, p);
}

static int cfe_subscribe_event(struct v4l2_fh *fh,
			       const struct v4l2_event_subscription *sub)
{
	struct cfe_node *node = video_get_drvdata(fh->vdev);

	switch (sub->type) {
	case V4L2_EVENT_FRAME_SYNC:
		if (!node_supports_image_output(node))
			break;

		return v4l2_event_subscribe(fh, sub, 2, NULL);
	case V4L2_EVENT_SOURCE_CHANGE:
		if (!node_supports_image_output(node) &&
		    !node_supports_meta_output(node))
			break;

		return v4l2_event_subscribe(fh, sub, 4, NULL);
	}

	return v4l2_ctrl_subscribe_event(fh, sub);
}

static const struct v4l2_ioctl_ops cfe_ioctl_ops = {
	.vidioc_querycap = cfe_querycap,
	.vidioc_enum_fmt_vid_cap = cfe_enum_fmt_vid_cap,
	.vidioc_g_fmt_vid_cap = cfe_g_fmt,
	.vidioc_s_fmt_vid_cap = cfe_s_fmt_vid_cap,
	.vidioc_try_fmt_vid_cap = cfe_try_fmt_vid_cap,

	.vidioc_enum_fmt_meta_cap = cfe_enum_fmt_meta,
	.vidioc_g_fmt_meta_cap = cfe_g_fmt_meta,
	.vidioc_s_fmt_meta_cap = cfe_s_fmt_meta,
	.vidioc_try_fmt_meta_cap = cfe_try_fmt_meta,

	.vidioc_enum_fmt_meta_out = cfe_enum_fmt_meta,
	.vidioc_g_fmt_meta_out = cfe_g_fmt_meta,
	.vidioc_s_fmt_meta_out = cfe_s_fmt_meta,
	.vidioc_try_fmt_meta_out = cfe_try_fmt_meta,

	.vidioc_enum_framesizes = cfe_enum_framesizes,

	.vidioc_reqbufs = cfe_vb2_ioctl_reqbufs,
	.vidioc_create_bufs = cfe_vb2_ioctl_create_bufs,
	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
	.vidioc_querybuf = vb2_ioctl_querybuf,
	.vidioc_qbuf = vb2_ioctl_qbuf,
	.vidioc_dqbuf = vb2_ioctl_dqbuf,
	.vidioc_expbuf = vb2_ioctl_expbuf,
	.vidioc_streamon = vb2_ioctl_streamon,
	.vidioc_streamoff = vb2_ioctl_streamoff,

	.vidioc_subscribe_event = cfe_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static void cfe_notify(struct v4l2_subdev *sd, unsigned int notification,
		       void *arg)
{
	struct cfe_device *cfe = to_cfe_device(sd->v4l2_dev);

	switch (notification) {
	case V4L2_DEVICE_NOTIFY_EVENT:
		for (unsigned int i = 0; i < NUM_NODES; i++) {
			struct cfe_node *node = &cfe->node[i];

			if (check_state(cfe, NODE_REGISTERED, i))
				continue;

			v4l2_event_queue(&node->video_dev, arg);
		}
		break;
	default:
		break;
	}
}

/* cfe capture driver file operations */
static const struct v4l2_file_operations cfe_fops = {
	.owner = THIS_MODULE,
	.open = v4l2_fh_open,
	.release = vb2_fop_release,
	.poll = vb2_fop_poll,
	.unlocked_ioctl = video_ioctl2,
	.mmap = vb2_fop_mmap,
};

static int cfe_video_link_validate(struct media_link *link)
{
	struct video_device *vd = container_of(link->sink->entity,
					       struct video_device, entity);
	struct cfe_node *node = container_of(vd, struct cfe_node, video_dev);
	struct cfe_device *cfe = node->cfe;
	struct v4l2_mbus_framefmt *source_fmt;
	struct v4l2_subdev_state *state;
	struct v4l2_subdev *source_sd;
	int ret = 0;

	cfe_dbg(cfe, "%s: [%s] link \"%s\":%u -> \"%s\":%u\n", __func__,
		node_desc[node->id].name,
		link->source->entity->name, link->source->index,
		link->sink->entity->name, link->sink->index);

	if (!media_entity_remote_source_pad_unique(link->sink->entity)) {
		cfe_err(cfe, "video node %s pad not connected\n", vd->name);
		return -ENOTCONN;
	}

	source_sd = media_entity_to_v4l2_subdev(link->source->entity);

	state = v4l2_subdev_lock_and_get_active_state(source_sd);

	source_fmt = v4l2_subdev_state_get_format(state, link->source->index);
	if (!source_fmt) {
		ret = -EINVAL;
		goto out;
	}

	if (is_image_output_node(node)) {
		struct v4l2_pix_format *pix_fmt = &node->vid_fmt.fmt.pix;
		const struct cfe_fmt *fmt;

		if (source_fmt->width != pix_fmt->width ||
		    source_fmt->height != pix_fmt->height) {
			cfe_err(cfe, "Wrong width or height %ux%u (remote pad set to %ux%u)\n",
				pix_fmt->width, pix_fmt->height,
				source_fmt->width, source_fmt->height);
			ret = -EINVAL;
			goto out;
		}

		fmt = find_format_by_code_and_fourcc(source_fmt->code,
						     pix_fmt->pixelformat);
		if (!fmt) {
			cfe_err(cfe, "Format mismatch!\n");
			ret = -EINVAL;
			goto out;
		}
	} else if (is_csi2_node(node) && is_meta_output_node(node)) {
		struct v4l2_meta_format *meta_fmt = &node->meta_fmt.fmt.meta;
		const struct cfe_fmt *fmt;

		if (source_fmt->width != meta_fmt->width ||
		    source_fmt->height != meta_fmt->height) {
			cfe_err(cfe, "Wrong width or height %ux%u (remote pad set to %ux%u)\n",
				meta_fmt->width, meta_fmt->height,
				source_fmt->width, source_fmt->height);
			ret = -EINVAL;
			goto out;
		}

		fmt = find_format_by_code_and_fourcc(source_fmt->code,
						     meta_fmt->dataformat);
		if (!fmt) {
			cfe_err(cfe, "Format mismatch!\n");
			ret = -EINVAL;
			goto out;
		}
	}

out:
	v4l2_subdev_unlock_state(state);

	return ret;
}

static const struct media_entity_operations cfe_media_entity_ops = {
	.link_validate = cfe_video_link_validate,
};

static int cfe_video_link_notify(struct media_link *link, u32 flags,
				 unsigned int notification)
{
	struct media_device *mdev = link->graph_obj.mdev;
	struct cfe_device *cfe = container_of(mdev, struct cfe_device, mdev);
	struct media_entity *fe = &cfe->fe.sd.entity;
	struct media_entity *csi2 = &cfe->csi2.sd.entity;
	unsigned long lock_flags;

	if (notification != MEDIA_DEV_NOTIFY_POST_LINK_CH)
		return 0;

	cfe_dbg(cfe, "%s: %s[%u] -> %s[%u] 0x%x", __func__,
		link->source->entity->name, link->source->index,
		link->sink->entity->name, link->sink->index, flags);

	spin_lock_irqsave(&cfe->state_lock, lock_flags);

	for (unsigned int i = 0; i < NUM_NODES; i++) {
		if (link->sink->entity != &cfe->node[i].video_dev.entity &&
		    link->source->entity != &cfe->node[i].video_dev.entity)
			continue;

		if (link->flags & MEDIA_LNK_FL_ENABLED)
			set_state(cfe, NODE_ENABLED, i);
		else
			clear_state(cfe, NODE_ENABLED, i);

		break;
	}

	spin_unlock_irqrestore(&cfe->state_lock, lock_flags);

	if (link->source->entity != csi2)
		return 0;
	if (link->sink->entity != fe)
		return 0;
	if (link->sink->index != 0)
		return 0;

	cfe->fe_csi2_channel = -1;
	if (link->flags & MEDIA_LNK_FL_ENABLED) {
		if (link->source->index == node_desc[CSI2_CH0].link_pad)
			cfe->fe_csi2_channel = CSI2_CH0;
		else if (link->source->index == node_desc[CSI2_CH1].link_pad)
			cfe->fe_csi2_channel = CSI2_CH1;
		else if (link->source->index == node_desc[CSI2_CH2].link_pad)
			cfe->fe_csi2_channel = CSI2_CH2;
		else if (link->source->index == node_desc[CSI2_CH3].link_pad)
			cfe->fe_csi2_channel = CSI2_CH3;
	}

	if (is_fe_enabled(cfe))
		cfe_dbg(cfe, "%s: Found CSI2:%d -> FE:0 link\n", __func__,
			cfe->fe_csi2_channel);
	else
		cfe_dbg(cfe, "%s: Unable to find CSI2:x -> FE:0 link\n",
			__func__);

	return 0;
}

static const struct media_device_ops cfe_media_device_ops = {
	.link_notify = cfe_video_link_notify,
};

static void cfe_release(struct kref *kref)
{
	struct cfe_device *cfe = container_of(kref, struct cfe_device, kref);

	media_device_cleanup(&cfe->mdev);

	kfree(cfe);
}

static void cfe_put(struct cfe_device *cfe)
{
	kref_put(&cfe->kref, cfe_release);
}

static void cfe_get(struct cfe_device *cfe)
{
	kref_get(&cfe->kref);
}

static void cfe_node_release(struct video_device *vdev)
{
	struct cfe_node *node = video_get_drvdata(vdev);

	cfe_put(node->cfe);
}

static int cfe_register_node(struct cfe_device *cfe, int id)
{
	struct video_device *vdev;
	const struct cfe_fmt *fmt;
	struct vb2_queue *q;
	struct cfe_node *node = &cfe->node[id];
	int ret;

	node->cfe = cfe;
	node->id = id;

	if (node_supports_image(node)) {
		if (node_supports_image_output(node))
			node->vid_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
		else
			node->vid_fmt.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;

		fmt = find_format_by_code(cfe_default_format.code);
		if (!fmt) {
			cfe_err(cfe, "Failed to find format code\n");
			return -EINVAL;
		}

		node->vid_fmt.fmt.pix.pixelformat = fmt->fourcc;
		v4l2_fill_pix_format(&node->vid_fmt.fmt.pix,
				     &cfe_default_format);

		ret = cfe_validate_fmt_vid_cap(node, &node->vid_fmt);
		if (ret)
			return ret;
	}

	if (node_supports_meta(node)) {
		if (node_supports_meta_output(node))
			node->meta_fmt.type = V4L2_BUF_TYPE_META_CAPTURE;
		else
			node->meta_fmt.type = V4L2_BUF_TYPE_META_OUTPUT;

		ret = cfe_validate_fmt_meta(node, &node->meta_fmt);
		if (ret)
			return ret;
	}

	mutex_init(&node->lock);

	q = &node->buffer_queue;
	q->type = node_supports_image(node) ? node->vid_fmt.type :
					      node->meta_fmt.type;
	q->io_modes = VB2_MMAP | VB2_DMABUF;
	q->drv_priv = node;
	q->ops = &cfe_video_qops;
	q->mem_ops = &vb2_dma_contig_memops;
	q->buf_struct_size = id == FE_CONFIG ? sizeof(struct cfe_config_buffer)
					     : sizeof(struct cfe_buffer);
	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
	q->lock = &node->lock;
	q->min_queued_buffers = 1;
	q->dev = &cfe->pdev->dev;

	ret = vb2_queue_init(q);
	if (ret) {
		cfe_err(cfe, "vb2_queue_init() failed\n");
		return ret;
	}

	INIT_LIST_HEAD(&node->dma_queue);

	vdev = &node->video_dev;
	vdev->release = cfe_node_release;
	vdev->fops = &cfe_fops;
	vdev->ioctl_ops = &cfe_ioctl_ops;
	vdev->entity.ops = &cfe_media_entity_ops;
	vdev->v4l2_dev = &cfe->v4l2_dev;
	vdev->vfl_dir = (node_supports_image_output(node) ||
			 node_supports_meta_output(node)) ?
				VFL_DIR_RX :
				VFL_DIR_TX;
	vdev->queue = q;
	vdev->lock = &node->lock;
	vdev->device_caps = node_desc[id].caps;
	vdev->device_caps |= V4L2_CAP_STREAMING | V4L2_CAP_IO_MC;

	/* Define the device names */
	snprintf(vdev->name, sizeof(vdev->name), "%s-%s", CFE_MODULE_NAME,
		 node_desc[id].name);

	video_set_drvdata(vdev, node);
	node->pad.flags = node_desc[id].pad_flags;
	media_entity_pads_init(&vdev->entity, 1, &node->pad);

	if (!node_supports_image(node)) {
		v4l2_disable_ioctl(&node->video_dev,
				   VIDIOC_ENUM_FRAMEINTERVALS);
		v4l2_disable_ioctl(&node->video_dev, VIDIOC_ENUM_FRAMESIZES);
	}

	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
	if (ret) {
		cfe_err(cfe, "Unable to register video device %s\n",
			vdev->name);
		return ret;
	}

	cfe_info(cfe, "Registered [%s] node id %d as /dev/video%u\n",
		 vdev->name, id, vdev->num);

	/*
	 * Acquire a reference to cfe, which will be released when the video
	 * device will be unregistered and userspace will have closed all open
	 * file handles.
	 */
	cfe_get(cfe);
	set_state(cfe, NODE_REGISTERED, id);

	return 0;
}

static void cfe_unregister_nodes(struct cfe_device *cfe)
{
	for (unsigned int i = 0; i < NUM_NODES; i++) {
		struct cfe_node *node = &cfe->node[i];

		if (check_state(cfe, NODE_REGISTERED, i)) {
			clear_state(cfe, NODE_REGISTERED, i);
			video_unregister_device(&node->video_dev);
		}
	}
}

static int cfe_link_node_pads(struct cfe_device *cfe)
{
	struct media_pad *remote_pad;
	int ret;

	/* Source -> CSI2 */

	ret = v4l2_create_fwnode_links_to_pad(cfe->source_sd,
					      &cfe->csi2.pad[CSI2_PAD_SINK],
					      MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);

	if (ret) {
		cfe_err(cfe, "Failed to create links to the source: %d\n", ret);
		return ret;
	}

	remote_pad = media_pad_remote_pad_unique(&cfe->csi2.pad[CSI2_PAD_SINK]);
	if (IS_ERR(remote_pad)) {
		ret = PTR_ERR(remote_pad);
		cfe_err(cfe, "Failed to get unique remote source pad: %d\n",
			ret);
		return ret;
	}

	cfe->source_pad = remote_pad->index;

	for (unsigned int i = 0; i < CSI2_NUM_CHANNELS; i++) {
		struct cfe_node *node = &cfe->node[i];

		if (!check_state(cfe, NODE_REGISTERED, i))
			continue;

		/* CSI2 channel # -> /dev/video# */
		ret = media_create_pad_link(&cfe->csi2.sd.entity,
					    node_desc[i].link_pad,
					    &node->video_dev.entity, 0, 0);
		if (ret)
			return ret;

		if (node_supports_image(node)) {
			/* CSI2 channel # -> FE Input */
			ret = media_create_pad_link(&cfe->csi2.sd.entity,
						    node_desc[i].link_pad,
						    &cfe->fe.sd.entity,
						    FE_STREAM_PAD, 0);
			if (ret)
				return ret;
		}
	}

	for (unsigned int i = CSI2_NUM_CHANNELS; i < NUM_NODES; i++) {
		struct cfe_node *node = &cfe->node[i];
		struct media_entity *src, *dst;
		unsigned int src_pad, dst_pad;

		if (node_desc[i].pad_flags & MEDIA_PAD_FL_SINK) {
			/* FE -> /dev/video# */
			src = &cfe->fe.sd.entity;
			src_pad = node_desc[i].link_pad;
			dst = &node->video_dev.entity;
			dst_pad = 0;
		} else {
			/* /dev/video# -> FE */
			dst = &cfe->fe.sd.entity;
			dst_pad = node_desc[i].link_pad;
			src = &node->video_dev.entity;
			src_pad = 0;
		}

		ret = media_create_pad_link(src, src_pad, dst, dst_pad, 0);
		if (ret)
			return ret;
	}

	return 0;
}

static int cfe_probe_complete(struct cfe_device *cfe)
{
	int ret;

	cfe->v4l2_dev.notify = cfe_notify;

	for (unsigned int i = 0; i < NUM_NODES; i++) {
		ret = cfe_register_node(cfe, i);
		if (ret) {
			cfe_err(cfe, "Unable to register video node %u.\n", i);
			goto unregister;
		}
	}

	ret = cfe_link_node_pads(cfe);
	if (ret) {
		cfe_err(cfe, "Unable to link node pads.\n");
		goto unregister;
	}

	ret = v4l2_device_register_subdev_nodes(&cfe->v4l2_dev);
	if (ret) {
		cfe_err(cfe, "Unable to register subdev nodes.\n");
		goto unregister;
	}

	return 0;

unregister:
	cfe_unregister_nodes(cfe);
	return ret;
}

static int cfe_async_bound(struct v4l2_async_notifier *notifier,
			   struct v4l2_subdev *subdev,
			   struct v4l2_async_connection *asd)
{
	struct cfe_device *cfe = to_cfe_device(notifier->v4l2_dev);

	if (cfe->source_sd) {
		cfe_err(cfe, "Rejecting subdev %s (Already set!!)",
			subdev->name);
		return 0;
	}

	cfe->source_sd = subdev;

	cfe_dbg(cfe, "Using source %s for capture\n", subdev->name);

	return 0;
}

static int cfe_async_complete(struct v4l2_async_notifier *notifier)
{
	struct cfe_device *cfe = to_cfe_device(notifier->v4l2_dev);

	return cfe_probe_complete(cfe);
}

static const struct v4l2_async_notifier_operations cfe_async_ops = {
	.bound = cfe_async_bound,
	.complete = cfe_async_complete,
};

static int cfe_register_async_nf(struct cfe_device *cfe)
{
	struct platform_device *pdev = cfe->pdev;
	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
	struct fwnode_handle *local_ep_fwnode;
	struct v4l2_async_connection *asd;
	int ret;

	local_ep_fwnode = fwnode_graph_get_endpoint_by_id(pdev->dev.fwnode, 0,
							  0, 0);
	if (!local_ep_fwnode) {
		cfe_err(cfe, "Failed to find local endpoint fwnode\n");
		return -ENODEV;
	}

	/* Parse the local endpoint and validate its configuration. */
	ret = v4l2_fwnode_endpoint_parse(local_ep_fwnode, &ep);
	if (ret) {
		cfe_err(cfe, "Failed to find remote endpoint fwnode\n");
		goto err_put_local_fwnode;
	}

	for (unsigned int lane = 0; lane < ep.bus.mipi_csi2.num_data_lanes;
	     lane++) {
		if (ep.bus.mipi_csi2.data_lanes[lane] != lane + 1) {
			cfe_err(cfe, "Data lanes reordering not supported\n");
			ret = -EINVAL;
			goto err_put_local_fwnode;
		}
	}

	cfe->csi2.dphy.max_lanes = ep.bus.mipi_csi2.num_data_lanes;
	cfe->csi2.bus_flags = ep.bus.mipi_csi2.flags;

	/* Initialize and register the async notifier. */
	v4l2_async_nf_init(&cfe->notifier, &cfe->v4l2_dev);
	cfe->notifier.ops = &cfe_async_ops;

	asd = v4l2_async_nf_add_fwnode_remote(&cfe->notifier, local_ep_fwnode,
					      struct v4l2_async_connection);
	if (IS_ERR(asd)) {
		ret = PTR_ERR(asd);
		cfe_err(cfe, "Error adding subdevice: %d\n", ret);
		goto err_put_local_fwnode;
	}

	ret = v4l2_async_nf_register(&cfe->notifier);
	if (ret) {
		cfe_err(cfe, "Error registering async notifier: %d\n", ret);
		goto err_nf_cleanup;
	}

	fwnode_handle_put(local_ep_fwnode);

	return 0;

err_nf_cleanup:
	v4l2_async_nf_cleanup(&cfe->notifier);
err_put_local_fwnode:
	fwnode_handle_put(local_ep_fwnode);

	return ret;
}

static int cfe_probe(struct platform_device *pdev)
{
	struct cfe_device *cfe;
	char debugfs_name[32];
	int ret;

	cfe = kzalloc(sizeof(*cfe), GFP_KERNEL);
	if (!cfe)
		return -ENOMEM;

	platform_set_drvdata(pdev, cfe);

	kref_init(&cfe->kref);
	cfe->pdev = pdev;
	cfe->fe_csi2_channel = -1;
	spin_lock_init(&cfe->state_lock);

	cfe->csi2.base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(cfe->csi2.base)) {
		dev_err(&pdev->dev, "Failed to get dma io block\n");
		ret = PTR_ERR(cfe->csi2.base);
		goto err_cfe_put;
	}

	cfe->csi2.dphy.base = devm_platform_ioremap_resource(pdev, 1);
	if (IS_ERR(cfe->csi2.dphy.base)) {
		dev_err(&pdev->dev, "Failed to get host io block\n");
		ret = PTR_ERR(cfe->csi2.dphy.base);
		goto err_cfe_put;
	}

	cfe->mipi_cfg_base = devm_platform_ioremap_resource(pdev, 2);
	if (IS_ERR(cfe->mipi_cfg_base)) {
		dev_err(&pdev->dev, "Failed to get mipi cfg io block\n");
		ret = PTR_ERR(cfe->mipi_cfg_base);
		goto err_cfe_put;
	}

	cfe->fe.base = devm_platform_ioremap_resource(pdev, 3);
	if (IS_ERR(cfe->fe.base)) {
		dev_err(&pdev->dev, "Failed to get pisp fe io block\n");
		ret = PTR_ERR(cfe->fe.base);
		goto err_cfe_put;
	}

	ret = platform_get_irq(pdev, 0);
	if (ret <= 0) {
		ret = -EINVAL;
		goto err_cfe_put;
	}

	ret = devm_request_irq(&pdev->dev, ret, cfe_isr, 0, "rp1-cfe", cfe);
	if (ret) {
		dev_err(&pdev->dev, "Unable to request interrupt\n");
		ret = -EINVAL;
		goto err_cfe_put;
	}

	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (ret) {
		dev_err(&pdev->dev, "DMA enable failed\n");
		goto err_cfe_put;
	}

	ret = vb2_dma_contig_set_max_seg_size(&pdev->dev, UINT_MAX);
	if (ret)
		goto err_cfe_put;

	/* TODO: Enable clock only when running. */
	cfe->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(cfe->clk)) {
		ret = dev_err_probe(&pdev->dev, PTR_ERR(cfe->clk),
				    "clock not found\n");
		goto err_cfe_put;
	}

	cfe->mdev.dev = &pdev->dev;
	cfe->mdev.ops = &cfe_media_device_ops;
	strscpy(cfe->mdev.model, CFE_MODULE_NAME, sizeof(cfe->mdev.model));
	strscpy(cfe->mdev.serial, "", sizeof(cfe->mdev.serial));
	snprintf(cfe->mdev.bus_info, sizeof(cfe->mdev.bus_info), "platform:%s",
		 dev_name(&pdev->dev));

	media_device_init(&cfe->mdev);

	cfe->v4l2_dev.mdev = &cfe->mdev;

	ret = v4l2_device_register(&pdev->dev, &cfe->v4l2_dev);
	if (ret) {
		cfe_err(cfe, "Unable to register v4l2 device.\n");
		goto err_cfe_put;
	}

	snprintf(debugfs_name, sizeof(debugfs_name), "rp1-cfe:%s",
		 dev_name(&pdev->dev));
	cfe->debugfs = debugfs_create_dir(debugfs_name, NULL);
	debugfs_create_file("regs", 0440, cfe->debugfs, cfe,
			    &mipi_cfg_regs_fops);

	/* Enable the block power domain */
	pm_runtime_enable(&pdev->dev);

	ret = pm_runtime_resume_and_get(&cfe->pdev->dev);
	if (ret)
		goto err_runtime_disable;

	cfe->csi2.v4l2_dev = &cfe->v4l2_dev;
	ret = csi2_init(&cfe->csi2, cfe->debugfs);
	if (ret) {
		cfe_err(cfe, "Failed to init csi2 (%d)\n", ret);
		goto err_runtime_put;
	}

	cfe->fe.v4l2_dev = &cfe->v4l2_dev;
	ret = pisp_fe_init(&cfe->fe, cfe->debugfs);
	if (ret) {
		cfe_err(cfe, "Failed to init pisp fe (%d)\n", ret);
		goto err_csi2_uninit;
	}

	cfe->mdev.hw_revision = cfe->fe.hw_revision;
	ret = media_device_register(&cfe->mdev);
	if (ret < 0) {
		cfe_err(cfe, "Unable to register media-controller device.\n");
		goto err_pisp_fe_uninit;
	}

	ret = cfe_register_async_nf(cfe);
	if (ret) {
		cfe_err(cfe, "Failed to connect subdevs\n");
		goto err_media_unregister;
	}

	pm_runtime_put(&cfe->pdev->dev);

	return 0;

err_media_unregister:
	media_device_unregister(&cfe->mdev);
err_pisp_fe_uninit:
	pisp_fe_uninit(&cfe->fe);
err_csi2_uninit:
	csi2_uninit(&cfe->csi2);
err_runtime_put:
	pm_runtime_put(&cfe->pdev->dev);
err_runtime_disable:
	pm_runtime_disable(&pdev->dev);
	debugfs_remove(cfe->debugfs);
	v4l2_device_unregister(&cfe->v4l2_dev);
err_cfe_put:
	cfe_put(cfe);

	return ret;
}

static void cfe_remove(struct platform_device *pdev)
{
	struct cfe_device *cfe = platform_get_drvdata(pdev);

	debugfs_remove(cfe->debugfs);

	v4l2_async_nf_unregister(&cfe->notifier);
	v4l2_async_nf_cleanup(&cfe->notifier);

	media_device_unregister(&cfe->mdev);
	cfe_unregister_nodes(cfe);

	pisp_fe_uninit(&cfe->fe);
	csi2_uninit(&cfe->csi2);

	pm_runtime_disable(&pdev->dev);

	v4l2_device_unregister(&cfe->v4l2_dev);

	cfe_put(cfe);
}

static int cfe_runtime_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct cfe_device *cfe = platform_get_drvdata(pdev);

	clk_disable_unprepare(cfe->clk);

	return 0;
}

static int cfe_runtime_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct cfe_device *cfe = platform_get_drvdata(pdev);
	int ret;

	ret = clk_prepare_enable(cfe->clk);
	if (ret) {
		dev_err(dev, "Unable to enable clock\n");
		return ret;
	}

	return 0;
}

static const struct dev_pm_ops cfe_pm_ops = {
	SET_RUNTIME_PM_OPS(cfe_runtime_suspend, cfe_runtime_resume, NULL)
	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
				     pm_runtime_force_resume)
};

static const struct of_device_id cfe_of_match[] = {
	{ .compatible = "raspberrypi,rp1-cfe" },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, cfe_of_match);

static struct platform_driver cfe_driver = {
	.probe		= cfe_probe,
	.remove		= cfe_remove,
	.driver = {
		.name	= CFE_MODULE_NAME,
		.of_match_table = cfe_of_match,
		.pm = &cfe_pm_ops,
	},
};

module_platform_driver(cfe_driver);

MODULE_AUTHOR("Naushir Patuck <naush@raspberrypi.com>");
MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>");
MODULE_DESCRIPTION("Raspberry Pi RP1 Camera Front End driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(CFE_VERSION);