// SPDX-License-Identifier: GPL-2.0
/*
 * V4L2 Driver for Renesas Capture Engine Unit (CEU) interface
 * Copyright (C) 2017-2018 Jacopo Mondi <jacopo+renesas@jmondi.org>
 *
 * Based on soc-camera driver "soc_camera/sh_mobile_ceu_camera.c"
 * Copyright (C) 2008 Magnus Damm
 *
 * Based on V4L2 Driver for PXA camera host - "pxa_camera.c",
 * Copyright (C) 2006, Sascha Hauer, Pengutronix
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/time.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-image-sizes.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mediabus.h>
#include <media/videobuf2-dma-contig.h>

#include <media/drv-intf/renesas-ceu.h>

#define DRIVER_NAME     "renesas-ceu"

/* CEU registers offsets and masks. */
#define CEU_CAPSR       0x00 /* Capture start register                  */
#define CEU_CAPCR       0x04 /* Capture control register                */
#define CEU_CAMCR       0x08 /* Capture interface control register      */
#define CEU_CAMOR       0x10 /* Capture interface offset register       */
#define CEU_CAPWR       0x14 /* Capture interface width register        */
#define CEU_CAIFR       0x18 /* Capture interface input format register */
#define CEU_CRCNTR      0x28 /* CEU register control register           */
#define CEU_CRCMPR      0x2c /* CEU register forcible control register  */
#define CEU_CFLCR       0x30 /* Capture filter control register         */
#define CEU_CFSZR       0x34 /* Capture filter size clip register       */
#define CEU_CDWDR       0x38 /* Capture destination width register      */
#define CEU_CDAYR       0x3c /* Capture data address Y register         */
#define CEU_CDACR       0x40 /* Capture data address C register         */
#define CEU_CFWCR       0x5c /* Firewall operation control register     */
#define CEU_CDOCR       0x64 /* Capture data output control register    */
#define CEU_CEIER       0x70 /* Capture event interrupt enable register */
#define CEU_CETCR       0x74 /* Capture event flag clear register       */
#define CEU_CSTSR       0x7c /* Capture status register                 */
#define CEU_CSRTR       0x80 /* Capture software reset register         */

/* Data synchronous fetch mode. */
#define CEU_CAMCR_JPEG                  BIT(4)

/* Input components ordering: CEU_CAMCR.DTARY field. */
#define CEU_CAMCR_DTARY_8_UYVY          (0x00 << 8)
#define CEU_CAMCR_DTARY_8_VYUY          (0x01 << 8)
#define CEU_CAMCR_DTARY_8_YUYV          (0x02 << 8)
#define CEU_CAMCR_DTARY_8_YVYU          (0x03 << 8)
/* TODO: input components ordering for 16 bits input. */

/* Bus transfer MTU. */
#define CEU_CAPCR_BUS_WIDTH256          (0x3 << 20)

/* Bus width configuration. */
#define CEU_CAMCR_DTIF_16BITS           BIT(12)

/* No downsampling to planar YUV420 in image fetch mode. */
#define CEU_CDOCR_NO_DOWSAMPLE          BIT(4)

/* Swap all input data in 8-bit, 16-bits and 32-bits units (Figure 46.45). */
#define CEU_CDOCR_SWAP_ENDIANNESS       (7)

/* Capture reset and enable bits. */
#define CEU_CAPSR_CPKIL                 BIT(16)
#define CEU_CAPSR_CE                    BIT(0)

/* CEU operating flag bit. */
#define CEU_CAPCR_CTNCP                 BIT(16)
#define CEU_CSTRST_CPTON                BIT(0)

/* Platform specific IRQ source flags. */
#define CEU_CETCR_ALL_IRQS_RZ           0x397f313
#define CEU_CETCR_ALL_IRQS_SH4          0x3d7f313

/* Prohibited register access interrupt bit. */
#define CEU_CETCR_IGRW                  BIT(4)
/* One-frame capture end interrupt. */
#define CEU_CEIER_CPE                   BIT(0)
/* VBP error. */
#define CEU_CEIER_VBP                   BIT(20)
#define CEU_CEIER_MASK                  (CEU_CEIER_CPE | CEU_CEIER_VBP)

#define CEU_MAX_WIDTH   2560
#define CEU_MAX_HEIGHT  1920
#define CEU_MAX_BPL     8188
#define CEU_W_MAX(w)    ((w) < CEU_MAX_WIDTH ? (w) : CEU_MAX_WIDTH)
#define CEU_H_MAX(h)    ((h) < CEU_MAX_HEIGHT ? (h) : CEU_MAX_HEIGHT)

/*
 * ceu_bus_fmt - describe a 8-bits yuyv format the sensor can produce
 *
 * @mbus_code: bus format code
 * @fmt_order: CEU_CAMCR.DTARY ordering of input components (Y, Cb, Cr)
 * @fmt_order_swap: swapped CEU_CAMCR.DTARY ordering of input components
 *                  (Y, Cr, Cb)
 * @swapped: does Cr appear before Cb?
 * @bps: number of bits sent over bus for each sample
 * @bpp: number of bits per pixels unit
 */
struct ceu_mbus_fmt {
        u32     mbus_code;
        u32     fmt_order;
        u32     fmt_order_swap;
        bool    swapped;
        u8      bps;
        u8      bpp;
};

/*
 * ceu_buffer - Link vb2 buffer to the list of available buffers.
 */
struct ceu_buffer {
        struct vb2_v4l2_buffer vb;
        struct list_head queue;
};

static inline struct ceu_buffer *vb2_to_ceu(struct vb2_v4l2_buffer *vbuf)
{
        return container_of(vbuf, struct ceu_buffer, vb);
}

/*
 * ceu_subdev - Wraps v4l2 sub-device and provides async subdevice.
 */
struct ceu_subdev {
        struct v4l2_async_subdev asd;
        struct v4l2_subdev *v4l2_sd;

        /* per-subdevice mbus configuration options */
        unsigned int mbus_flags;
        struct ceu_mbus_fmt mbus_fmt;
};

static struct ceu_subdev *to_ceu_subdev(struct v4l2_async_subdev *asd)
{
        return container_of(asd, struct ceu_subdev, asd);
}

/*
 * ceu_device - CEU device instance
 */
struct ceu_device {
        struct device           *dev;
        struct video_device     vdev;
        struct v4l2_device      v4l2_dev;

        /* subdevices descriptors */
        struct ceu_subdev       **subdevs;
        /* the subdevice currently in use */
        struct ceu_subdev       *sd;
        unsigned int            sd_index;
        unsigned int            num_sd;

        /* platform specific mask with all IRQ sources flagged */
        u32                     irq_mask;

        /* currently configured field and pixel format */
        enum v4l2_field field;
        struct v4l2_pix_format_mplane v4l2_pix;

        /* async subdev notification helpers */
        struct v4l2_async_notifier notifier;

        /* vb2 queue, capture buffer list and active buffer pointer */
        struct vb2_queue        vb2_vq;
        struct list_head        capture;
        struct vb2_v4l2_buffer  *active;
        unsigned int            sequence;

        /* mlock - lock access to interface reset and vb2 queue */
        struct mutex    mlock;

        /* lock - lock access to capture buffer queue and active buffer */
        spinlock_t      lock;

        /* base - CEU memory base address */
        void __iomem    *base;
};

static inline struct ceu_device *v4l2_to_ceu(struct v4l2_device *v4l2_dev)
{
        return container_of(v4l2_dev, struct ceu_device, v4l2_dev);
}

/* --- CEU memory output formats --- */

/*
 * ceu_fmt - describe a memory output format supported by CEU interface.
 *
 * @fourcc: memory layout fourcc format code
 * @bpp: number of bits for each pixel stored in memory
 */
struct ceu_fmt {
        u32     fourcc;
        u32     bpp;
};

/*
 * ceu_format_list - List of supported memory output formats
 *
 * If sensor provides any YUYV bus format, all the following planar memory
 * formats are available thanks to CEU re-ordering and sub-sampling
 * capabilities.
 */
static const struct ceu_fmt ceu_fmt_list[] = {
        {
                .fourcc = V4L2_PIX_FMT_NV16,
                .bpp    = 16,
        },
        {
                .fourcc = V4L2_PIX_FMT_NV61,
                .bpp    = 16,
        },
        {
                .fourcc = V4L2_PIX_FMT_NV12,
                .bpp    = 12,
        },
        {
                .fourcc = V4L2_PIX_FMT_NV21,
                .bpp    = 12,
        },
        {
                .fourcc = V4L2_PIX_FMT_YUYV,
                .bpp    = 16,
        },
        {
                .fourcc = V4L2_PIX_FMT_UYVY,
                .bpp    = 16,
        },
        {
                .fourcc = V4L2_PIX_FMT_YVYU,
                .bpp    = 16,
        },
        {
                .fourcc = V4L2_PIX_FMT_VYUY,
                .bpp    = 16,
        },
};

static const struct ceu_fmt *get_ceu_fmt_from_fourcc(unsigned int fourcc)
{
        const struct ceu_fmt *fmt = &ceu_fmt_list[0];
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(ceu_fmt_list); i++, fmt++)
                if (fmt->fourcc == fourcc)
                        return fmt;

        return NULL;
}

static bool ceu_fmt_mplane(struct v4l2_pix_format_mplane *pix)
{
        switch (pix->pixelformat) {
        case V4L2_PIX_FMT_YUYV:
        case V4L2_PIX_FMT_UYVY:
        case V4L2_PIX_FMT_YVYU:
        case V4L2_PIX_FMT_VYUY:
                return false;
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
                return true;
        default:
                return false;
        }
}

/* --- CEU HW operations --- */

static void ceu_write(struct ceu_device *priv, unsigned int reg_offs, u32 data)
{
        iowrite32(data, priv->base + reg_offs);
}

static u32 ceu_read(struct ceu_device *priv, unsigned int reg_offs)
{
        return ioread32(priv->base + reg_offs);
}

/*
 * ceu_soft_reset() - Software reset the CEU interface.
 * @ceu_device: CEU device.
 *
 * Returns 0 for success, -EIO for error.
 */
static int ceu_soft_reset(struct ceu_device *ceudev)
{
        unsigned int i;

        ceu_write(ceudev, CEU_CAPSR, CEU_CAPSR_CPKIL);

        for (i = 0; i < 100; i++) {
                if (!(ceu_read(ceudev, CEU_CSTSR) & CEU_CSTRST_CPTON))
                        break;
                udelay(1);
        }

        if (i == 100) {
                dev_err(ceudev->dev, "soft reset time out\n");
                return -EIO;
        }

        for (i = 0; i < 100; i++) {
                if (!(ceu_read(ceudev, CEU_CAPSR) & CEU_CAPSR_CPKIL))
                        return 0;
                udelay(1);
        }

        /* If we get here, CEU has not reset properly. */
        return -EIO;
}

/* --- CEU Capture Operations --- */

/*
 * ceu_hw_config() - Configure CEU interface registers.
 */
static int ceu_hw_config(struct ceu_device *ceudev)
{
        u32 camcr, cdocr, cfzsr, cdwdr, capwr;
        struct v4l2_pix_format_mplane *pix = &ceudev->v4l2_pix;
        struct ceu_subdev *ceu_sd = ceudev->sd;
        struct ceu_mbus_fmt *mbus_fmt = &ceu_sd->mbus_fmt;
        unsigned int mbus_flags = ceu_sd->mbus_flags;

        /* Start configuring CEU registers */
        ceu_write(ceudev, CEU_CAIFR, 0);
        ceu_write(ceudev, CEU_CFWCR, 0);
        ceu_write(ceudev, CEU_CRCNTR, 0);
        ceu_write(ceudev, CEU_CRCMPR, 0);

        /* Set the frame capture period for both image capture and data sync. */
        capwr = (pix->height << 16) | pix->width * mbus_fmt->bpp / 8;

        /*
         * Swap input data endianness by default.
         * In data fetch mode bytes are received in chunks of 8 bytes.
         * D0, D1, D2, D3, D4, D5, D6, D7 (D0 received first)
         * The data is however by default written to memory in reverse order:
         * D7, D6, D5, D4, D3, D2, D1, D0 (D7 written to lowest byte)
         *
         * Use CEU_CDOCR[2:0] to swap data ordering.
         */
        cdocr = CEU_CDOCR_SWAP_ENDIANNESS;

        /*
         * Configure CAMCR and CDOCR:
         * match input components ordering with memory output format and
         * handle downsampling to YUV420.
         *
         * If the memory output planar format is 'swapped' (Cr before Cb) and
         * input format is not, use the swapped version of CAMCR.DTARY.
         *
         * If the memory output planar format is not 'swapped' (Cb before Cr)
         * and input format is, use the swapped version of CAMCR.DTARY.
         *
         * CEU by default downsample to planar YUV420 (CDCOR[4] = 0).
         * If output is planar YUV422 set CDOCR[4] = 1
         *
         * No downsample for data fetch sync mode.
         */
        switch (pix->pixelformat) {
        /* Data fetch sync mode */
        case V4L2_PIX_FMT_YUYV:
        case V4L2_PIX_FMT_YVYU:
        case V4L2_PIX_FMT_UYVY:
        case V4L2_PIX_FMT_VYUY:
                camcr   = CEU_CAMCR_JPEG;
                cdocr   |= CEU_CDOCR_NO_DOWSAMPLE;
                cfzsr   = (pix->height << 16) | pix->width;
                cdwdr   = pix->plane_fmt[0].bytesperline;
                break;

        /* Non-swapped planar image capture mode. */
        case V4L2_PIX_FMT_NV16:
                cdocr   |= CEU_CDOCR_NO_DOWSAMPLE;
                fallthrough;
        case V4L2_PIX_FMT_NV12:
                if (mbus_fmt->swapped)
                        camcr = mbus_fmt->fmt_order_swap;
                else
                        camcr = mbus_fmt->fmt_order;

                cfzsr   = (pix->height << 16) | pix->width;
                cdwdr   = pix->width;
                break;

        /* Swapped planar image capture mode. */
        case V4L2_PIX_FMT_NV61:
                cdocr   |= CEU_CDOCR_NO_DOWSAMPLE;
                fallthrough;
        case V4L2_PIX_FMT_NV21:
                if (mbus_fmt->swapped)
                        camcr = mbus_fmt->fmt_order;
                else
                        camcr = mbus_fmt->fmt_order_swap;

                cfzsr   = (pix->height << 16) | pix->width;
                cdwdr   = pix->width;
                break;

        default:
                return -EINVAL;
        }

        camcr |= mbus_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW ? 1 << 1 : 0;
        camcr |= mbus_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW ? 1 << 0 : 0;

        /* TODO: handle 16 bit bus width with DTIF bit in CAMCR */
        ceu_write(ceudev, CEU_CAMCR, camcr);
        ceu_write(ceudev, CEU_CDOCR, cdocr);
        ceu_write(ceudev, CEU_CAPCR, CEU_CAPCR_BUS_WIDTH256);

        /*
         * TODO: make CAMOR offsets configurable.
         * CAMOR wants to know the number of blanks between a VS/HS signal
         * and valid data. This value should actually come from the sensor...
         */
        ceu_write(ceudev, CEU_CAMOR, 0);

        /* TODO: 16 bit bus width require re-calculation of cdwdr and cfzsr */
        ceu_write(ceudev, CEU_CAPWR, capwr);
        ceu_write(ceudev, CEU_CFSZR, cfzsr);
        ceu_write(ceudev, CEU_CDWDR, cdwdr);

        return 0;
}

/*
 * ceu_capture() - Trigger start of a capture sequence.
 *
 * Program the CEU DMA registers with addresses where to transfer image data.
 */
static int ceu_capture(struct ceu_device *ceudev)
{
        struct v4l2_pix_format_mplane *pix = &ceudev->v4l2_pix;
        dma_addr_t phys_addr_top;

        phys_addr_top =
                vb2_dma_contig_plane_dma_addr(&ceudev->active->vb2_buf, 0);
        ceu_write(ceudev, CEU_CDAYR, phys_addr_top);

        /* Ignore CbCr plane for non multi-planar image formats. */
        if (ceu_fmt_mplane(pix)) {
                phys_addr_top =
                        vb2_dma_contig_plane_dma_addr(&ceudev->active->vb2_buf,
                                                      1);
                ceu_write(ceudev, CEU_CDACR, phys_addr_top);
        }

        /*
         * Trigger new capture start: once for each frame, as we work in
         * one-frame capture mode.
         */
        ceu_write(ceudev, CEU_CAPSR, CEU_CAPSR_CE);

        return 0;
}

static irqreturn_t ceu_irq(int irq, void *data)
{
        struct ceu_device *ceudev = data;
        struct vb2_v4l2_buffer *vbuf;
        struct ceu_buffer *buf;
        u32 status;

        /* Clean interrupt status. */
        status = ceu_read(ceudev, CEU_CETCR);
        ceu_write(ceudev, CEU_CETCR, ~ceudev->irq_mask);

        /* Unexpected interrupt. */
        if (!(status & CEU_CEIER_MASK))
                return IRQ_NONE;

        spin_lock(&ceudev->lock);

        /* Stale interrupt from a released buffer, ignore it. */
        vbuf = ceudev->active;
        if (!vbuf) {
                spin_unlock(&ceudev->lock);
                return IRQ_HANDLED;
        }

        /*
         * When a VBP interrupt occurs, no capture end interrupt will occur
         * and the image of that frame is not captured correctly.
         */
        if (status & CEU_CEIER_VBP) {
                dev_err(ceudev->dev, "VBP interrupt: abort capture\n");
                goto error_irq_out;
        }

        /* Prepare to return the 'previous' buffer. */
        vbuf->vb2_buf.timestamp = ktime_get_ns();
        vbuf->sequence = ceudev->sequence++;
        vbuf->field = ceudev->field;

        /* Prepare a new 'active' buffer and trigger a new capture. */
        if (!list_empty(&ceudev->capture)) {
                buf = list_first_entry(&ceudev->capture, struct ceu_buffer,
                                       queue);
                list_del(&buf->queue);
                ceudev->active = &buf->vb;

                ceu_capture(ceudev);
        }

        /* Return the 'previous' buffer. */
        vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);

        spin_unlock(&ceudev->lock);

        return IRQ_HANDLED;

error_irq_out:
        /* Return the 'previous' buffer and all queued ones. */
        vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_ERROR);

        list_for_each_entry(buf, &ceudev->capture, queue)
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);

        spin_unlock(&ceudev->lock);

        return IRQ_HANDLED;
}

/* --- CEU Videobuf2 operations --- */

static void ceu_update_plane_sizes(struct v4l2_plane_pix_format *plane,
                                   unsigned int bpl, unsigned int szimage)
{
        memset(plane, 0, sizeof(*plane));

        plane->sizeimage = szimage;
        if (plane->bytesperline < bpl || plane->bytesperline > CEU_MAX_BPL)
                plane->bytesperline = bpl;
}

/*
 * ceu_calc_plane_sizes() - Fill per-plane 'struct v4l2_plane_pix_format'
 *                          information according to the currently configured
 *                          pixel format.
 * @ceu_device: CEU device.
 * @ceu_fmt: Active image format.
 * @pix: Pixel format information (store line width and image sizes)
 */
static void ceu_calc_plane_sizes(struct ceu_device *ceudev,
                                 const struct ceu_fmt *ceu_fmt,
                                 struct v4l2_pix_format_mplane *pix)
{
        unsigned int bpl, szimage;

        switch (pix->pixelformat) {
        case V4L2_PIX_FMT_YUYV:
        case V4L2_PIX_FMT_UYVY:
        case V4L2_PIX_FMT_YVYU:
        case V4L2_PIX_FMT_VYUY:
                pix->num_planes = 1;
                bpl             = pix->width * ceu_fmt->bpp / 8;
                szimage         = pix->height * bpl;
                ceu_update_plane_sizes(&pix->plane_fmt[0], bpl, szimage);
                break;

        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
                pix->num_planes = 2;
                bpl             = pix->width;
                szimage         = pix->height * pix->width;
                ceu_update_plane_sizes(&pix->plane_fmt[0], bpl, szimage);
                ceu_update_plane_sizes(&pix->plane_fmt[1], bpl, szimage / 2);
                break;

        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
        default:
                pix->num_planes = 2;
                bpl             = pix->width;
                szimage         = pix->height * pix->width;
                ceu_update_plane_sizes(&pix->plane_fmt[0], bpl, szimage);
                ceu_update_plane_sizes(&pix->plane_fmt[1], bpl, szimage);
                break;
        }
}

/*
 * ceu_vb2_setup() - is called to check whether the driver can accept the
 *                   requested number of buffers and to fill in plane sizes
 *                   for the current frame format, if required.
 */
static int ceu_vb2_setup(struct vb2_queue *vq, unsigned int *count,
                         unsigned int *num_planes, unsigned int sizes[],
                         struct device *alloc_devs[])
{
        struct ceu_device *ceudev = vb2_get_drv_priv(vq);
        struct v4l2_pix_format_mplane *pix = &ceudev->v4l2_pix;
        unsigned int i;

        /* num_planes is set: just check plane sizes. */
        if (*num_planes) {
                for (i = 0; i < pix->num_planes; i++)
                        if (sizes[i] < pix->plane_fmt[i].sizeimage)
                                return -EINVAL;

                return 0;
        }

        /* num_planes not set: called from REQBUFS, just set plane sizes. */
        *num_planes = pix->num_planes;
        for (i = 0; i < pix->num_planes; i++)
                sizes[i] = pix->plane_fmt[i].sizeimage;

        return 0;
}

static void ceu_vb2_queue(struct vb2_buffer *vb)
{
        struct ceu_device *ceudev = vb2_get_drv_priv(vb->vb2_queue);
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct ceu_buffer *buf = vb2_to_ceu(vbuf);
        unsigned long irqflags;

        spin_lock_irqsave(&ceudev->lock, irqflags);
        list_add_tail(&buf->queue, &ceudev->capture);
        spin_unlock_irqrestore(&ceudev->lock, irqflags);
}

static int ceu_vb2_prepare(struct vb2_buffer *vb)
{
        struct ceu_device *ceudev = vb2_get_drv_priv(vb->vb2_queue);
        struct v4l2_pix_format_mplane *pix = &ceudev->v4l2_pix;
        unsigned int i;

        for (i = 0; i < pix->num_planes; i++) {
                if (vb2_plane_size(vb, i) < pix->plane_fmt[i].sizeimage) {
                        dev_err(ceudev->dev,
                                "Plane size too small (%lu < %u)\n",
                                vb2_plane_size(vb, i),
                                pix->plane_fmt[i].sizeimage);
                        return -EINVAL;
                }

                vb2_set_plane_payload(vb, i, pix->plane_fmt[i].sizeimage);
        }

        return 0;
}

static int ceu_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct ceu_device *ceudev = vb2_get_drv_priv(vq);
        struct v4l2_subdev *v4l2_sd = ceudev->sd->v4l2_sd;
        struct ceu_buffer *buf;
        unsigned long irqflags;
        int ret;

        /* Program the CEU interface according to the CEU image format. */
        ret = ceu_hw_config(ceudev);
        if (ret)
                goto error_return_bufs;

        ret = v4l2_subdev_call(v4l2_sd, video, s_stream, 1);
        if (ret && ret != -ENOIOCTLCMD) {
                dev_dbg(ceudev->dev,
                        "Subdevice failed to start streaming: %d\n", ret);
                goto error_return_bufs;
        }

        spin_lock_irqsave(&ceudev->lock, irqflags);
        ceudev->sequence = 0;

        /* Grab the first available buffer and trigger the first capture. */
        buf = list_first_entry(&ceudev->capture, struct ceu_buffer,
                               queue);
        if (!buf) {
                spin_unlock_irqrestore(&ceudev->lock, irqflags);
                dev_dbg(ceudev->dev,
                        "No buffer available for capture.\n");
                goto error_stop_sensor;
        }

        list_del(&buf->queue);
        ceudev->active = &buf->vb;

        /* Clean and program interrupts for first capture. */
        ceu_write(ceudev, CEU_CETCR, ~ceudev->irq_mask);
        ceu_write(ceudev, CEU_CEIER, CEU_CEIER_MASK);

        ceu_capture(ceudev);

        spin_unlock_irqrestore(&ceudev->lock, irqflags);

        return 0;

error_stop_sensor:
        v4l2_subdev_call(v4l2_sd, video, s_stream, 0);

error_return_bufs:
        spin_lock_irqsave(&ceudev->lock, irqflags);
        list_for_each_entry(buf, &ceudev->capture, queue)
                vb2_buffer_done(&ceudev->active->vb2_buf,
                                VB2_BUF_STATE_QUEUED);
        ceudev->active = NULL;
        spin_unlock_irqrestore(&ceudev->lock, irqflags);

        return ret;
}

static void ceu_stop_streaming(struct vb2_queue *vq)
{
        struct ceu_device *ceudev = vb2_get_drv_priv(vq);
        struct v4l2_subdev *v4l2_sd = ceudev->sd->v4l2_sd;
        struct ceu_buffer *buf;
        unsigned long irqflags;

        /* Clean and disable interrupt sources. */
        ceu_write(ceudev, CEU_CETCR,
                  ceu_read(ceudev, CEU_CETCR) & ceudev->irq_mask);
        ceu_write(ceudev, CEU_CEIER, CEU_CEIER_MASK);

        v4l2_subdev_call(v4l2_sd, video, s_stream, 0);

        spin_lock_irqsave(&ceudev->lock, irqflags);
        if (ceudev->active) {
                vb2_buffer_done(&ceudev->active->vb2_buf,
                                VB2_BUF_STATE_ERROR);
                ceudev->active = NULL;
        }

        /* Release all queued buffers. */
        list_for_each_entry(buf, &ceudev->capture, queue)
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
        INIT_LIST_HEAD(&ceudev->capture);

        spin_unlock_irqrestore(&ceudev->lock, irqflags);

        ceu_soft_reset(ceudev);
}

static const struct vb2_ops ceu_vb2_ops = {
        .queue_setup            = ceu_vb2_setup,
        .buf_queue              = ceu_vb2_queue,
        .buf_prepare            = ceu_vb2_prepare,
        .wait_prepare           = vb2_ops_wait_prepare,
        .wait_finish            = vb2_ops_wait_finish,
        .start_streaming        = ceu_start_streaming,
        .stop_streaming         = ceu_stop_streaming,
};

/* --- CEU image formats handling --- */

/*
 * __ceu_try_fmt() - test format on CEU and sensor
 * @ceudev: The CEU device.
 * @v4l2_fmt: format to test.
 * @sd_mbus_code: the media bus code accepted by the subdevice; output param.
 *
 * Returns 0 for success, < 0 for errors.
 */
static int __ceu_try_fmt(struct ceu_device *ceudev, struct v4l2_format *v4l2_fmt,
                         u32 *sd_mbus_code)
{
        struct ceu_subdev *ceu_sd = ceudev->sd;
        struct v4l2_pix_format_mplane *pix = &v4l2_fmt->fmt.pix_mp;
        struct v4l2_subdev *v4l2_sd = ceu_sd->v4l2_sd;
        struct v4l2_subdev_pad_config pad_cfg;
        const struct ceu_fmt *ceu_fmt;
        u32 mbus_code_old;
        u32 mbus_code;
        int ret;

        /*
         * Set format on sensor sub device: bus format used to produce memory
         * format is selected depending on YUV component ordering or
         * at initialization time.
         */
        struct v4l2_subdev_format sd_format = {
                .which  = V4L2_SUBDEV_FORMAT_TRY,
        };

        mbus_code_old = ceu_sd->mbus_fmt.mbus_code;

        switch (pix->pixelformat) {
        case V4L2_PIX_FMT_YUYV:
                mbus_code = MEDIA_BUS_FMT_YUYV8_2X8;
                break;
        case V4L2_PIX_FMT_UYVY:
                mbus_code = MEDIA_BUS_FMT_UYVY8_2X8;
                break;
        case V4L2_PIX_FMT_YVYU:
                mbus_code = MEDIA_BUS_FMT_YVYU8_2X8;
                break;
        case V4L2_PIX_FMT_VYUY:
                mbus_code = MEDIA_BUS_FMT_VYUY8_2X8;
                break;
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
                mbus_code = ceu_sd->mbus_fmt.mbus_code;
                break;

        default:
                pix->pixelformat = V4L2_PIX_FMT_NV16;
                mbus_code = ceu_sd->mbus_fmt.mbus_code;
                break;
        }

        ceu_fmt = get_ceu_fmt_from_fourcc(pix->pixelformat);

        /* CFSZR requires height and width to be 4-pixel aligned. */
        v4l_bound_align_image(&pix->width, 2, CEU_MAX_WIDTH, 4,
                              &pix->height, 4, CEU_MAX_HEIGHT, 4, 0);

        v4l2_fill_mbus_format_mplane(&sd_format.format, pix);

        /*
         * Try with the mbus_code matching YUYV components ordering first,
         * if that one fails, fallback to default selected at initialization
         * time.
         */
        sd_format.format.code = mbus_code;
        ret = v4l2_subdev_call(v4l2_sd, pad, set_fmt, &pad_cfg, &sd_format);
        if (ret) {
                if (ret == -EINVAL) {
                        /* fallback */
                        sd_format.format.code = mbus_code_old;
                        ret = v4l2_subdev_call(v4l2_sd, pad, set_fmt,
                                               &pad_cfg, &sd_format);
                }

                if (ret)
                        return ret;
        }

        /* Apply size returned by sensor as the CEU can't scale. */
        v4l2_fill_pix_format_mplane(pix, &sd_format.format);

        /* Calculate per-plane sizes based on image format. */
        ceu_calc_plane_sizes(ceudev, ceu_fmt, pix);

        /* Report to caller the configured mbus format. */
        *sd_mbus_code = sd_format.format.code;

        return 0;
}

/*
 * ceu_try_fmt() - Wrapper for __ceu_try_fmt; discard configured mbus_fmt
 */
static int ceu_try_fmt(struct ceu_device *ceudev, struct v4l2_format *v4l2_fmt)
{
        u32 mbus_code;

        return __ceu_try_fmt(ceudev, v4l2_fmt, &mbus_code);
}

/*
 * ceu_set_fmt() - Apply the supplied format to both sensor and CEU
 */
static int ceu_set_fmt(struct ceu_device *ceudev, struct v4l2_format *v4l2_fmt)
{
        struct ceu_subdev *ceu_sd = ceudev->sd;
        struct v4l2_subdev *v4l2_sd = ceu_sd->v4l2_sd;
        u32 mbus_code;
        int ret;

        /*
         * Set format on sensor sub device: bus format used to produce memory
         * format is selected at initialization time.
         */
        struct v4l2_subdev_format format = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };

        ret = __ceu_try_fmt(ceudev, v4l2_fmt, &mbus_code);
        if (ret)
                return ret;

        format.format.code = mbus_code;
        v4l2_fill_mbus_format_mplane(&format.format, &v4l2_fmt->fmt.pix_mp);
        ret = v4l2_subdev_call(v4l2_sd, pad, set_fmt, NULL, &format);
        if (ret)
                return ret;

        ceudev->v4l2_pix = v4l2_fmt->fmt.pix_mp;
        ceudev->field = V4L2_FIELD_NONE;

        return 0;
}

/*
 * ceu_set_default_fmt() - Apply default NV16 memory output format with VGA
 *                         sizes.
 */
static int ceu_set_default_fmt(struct ceu_device *ceudev)
{
        int ret;

        struct v4l2_format v4l2_fmt = {
                .type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE,
                .fmt.pix_mp = {
                        .width          = VGA_WIDTH,
                        .height         = VGA_HEIGHT,
                        .field          = V4L2_FIELD_NONE,
                        .pixelformat    = V4L2_PIX_FMT_NV16,
                        .num_planes     = 2,
                        .plane_fmt      = {
                                [0]     = {
                                        .sizeimage = VGA_WIDTH * VGA_HEIGHT * 2,
                                        .bytesperline = VGA_WIDTH * 2,
                                },
                                [1]     = {
                                        .sizeimage = VGA_WIDTH * VGA_HEIGHT * 2,
                                        .bytesperline = VGA_WIDTH * 2,
                                },
                        },
                },
        };

        ret = ceu_try_fmt(ceudev, &v4l2_fmt);
        if (ret)
                return ret;

        ceudev->v4l2_pix = v4l2_fmt.fmt.pix_mp;
        ceudev->field = V4L2_FIELD_NONE;

        return 0;
}

/*
 * ceu_init_mbus_fmt() - Query sensor for supported formats and initialize
 *                       CEU media bus format used to produce memory formats.
 *
 * Find out if sensor can produce a permutation of 8-bits YUYV bus format.
 * From a single 8-bits YUYV bus format the CEU can produce several memory
 * output formats:
 * - NV[12|21|16|61] through image fetch mode;
 * - YUYV422 if sensor provides YUYV422
 *
 * TODO: Other YUYV422 permutations through data fetch sync mode and DTARY
 * TODO: Binary data (eg. JPEG) and raw formats through data fetch sync mode
 */
static int ceu_init_mbus_fmt(struct ceu_device *ceudev)
{
        struct ceu_subdev *ceu_sd = ceudev->sd;
        struct ceu_mbus_fmt *mbus_fmt = &ceu_sd->mbus_fmt;
        struct v4l2_subdev *v4l2_sd = ceu_sd->v4l2_sd;
        bool yuyv_bus_fmt = false;

        struct v4l2_subdev_mbus_code_enum sd_mbus_fmt = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
                .index = 0,
        };

        /* Find out if sensor can produce any permutation of 8-bits YUYV422. */
        while (!yuyv_bus_fmt &&
               !v4l2_subdev_call(v4l2_sd, pad, enum_mbus_code,
                                 NULL, &sd_mbus_fmt)) {
                switch (sd_mbus_fmt.code) {
                case MEDIA_BUS_FMT_YUYV8_2X8:
                case MEDIA_BUS_FMT_YVYU8_2X8:
                case MEDIA_BUS_FMT_UYVY8_2X8:
                case MEDIA_BUS_FMT_VYUY8_2X8:
                        yuyv_bus_fmt = true;
                        break;
                default:
                        /*
                         * Only support 8-bits YUYV bus formats at the moment;
                         *

                         * TODO: add support for binary formats (data sync
                         * fetch mode).
                         */
                        break;
                }

                sd_mbus_fmt.index++;
        }

        if (!yuyv_bus_fmt)
                return -ENXIO;

        /*
         * Save the first encountered YUYV format as "mbus_fmt" and use it
         * to output all planar YUV422 and YUV420 (NV*) formats to memory as
         * well as for data synch fetch mode (YUYV - YVYU etc. ).
         */
        mbus_fmt->mbus_code     = sd_mbus_fmt.code;
        mbus_fmt->bps           = 8;

        /* Annotate the selected bus format components ordering. */
        switch (sd_mbus_fmt.code) {
        case MEDIA_BUS_FMT_YUYV8_2X8:
                mbus_fmt->fmt_order             = CEU_CAMCR_DTARY_8_YUYV;
                mbus_fmt->fmt_order_swap        = CEU_CAMCR_DTARY_8_YVYU;
                mbus_fmt->swapped               = false;
                mbus_fmt->bpp                   = 16;
                break;

        case MEDIA_BUS_FMT_YVYU8_2X8:
                mbus_fmt->fmt_order             = CEU_CAMCR_DTARY_8_YVYU;
                mbus_fmt->fmt_order_swap        = CEU_CAMCR_DTARY_8_YUYV;
                mbus_fmt->swapped               = true;
                mbus_fmt->bpp                   = 16;
                break;

        case MEDIA_BUS_FMT_UYVY8_2X8:
                mbus_fmt->fmt_order             = CEU_CAMCR_DTARY_8_UYVY;
                mbus_fmt->fmt_order_swap        = CEU_CAMCR_DTARY_8_VYUY;
                mbus_fmt->swapped               = false;
                mbus_fmt->bpp                   = 16;
                break;

        case MEDIA_BUS_FMT_VYUY8_2X8:
                mbus_fmt->fmt_order             = CEU_CAMCR_DTARY_8_VYUY;
                mbus_fmt->fmt_order_swap        = CEU_CAMCR_DTARY_8_UYVY;
                mbus_fmt->swapped               = true;
                mbus_fmt->bpp                   = 16;
                break;
        }

        return 0;
}

/* --- Runtime PM Handlers --- */

/*
 * ceu_runtime_resume() - soft-reset the interface and turn sensor power on.
 */
static int __maybe_unused ceu_runtime_resume(struct device *dev)
{
        struct ceu_device *ceudev = dev_get_drvdata(dev);
        struct v4l2_subdev *v4l2_sd = ceudev->sd->v4l2_sd;

        v4l2_subdev_call(v4l2_sd, core, s_power, 1);

        ceu_soft_reset(ceudev);

        return 0;
}

/*
 * ceu_runtime_suspend() - disable capture and interrupts and soft-reset.
 *                         Turn sensor power off.
 */
static int __maybe_unused ceu_runtime_suspend(struct device *dev)
{
        struct ceu_device *ceudev = dev_get_drvdata(dev);
        struct v4l2_subdev *v4l2_sd = ceudev->sd->v4l2_sd;

        v4l2_subdev_call(v4l2_sd, core, s_power, 0);

        ceu_write(ceudev, CEU_CEIER, 0);
        ceu_soft_reset(ceudev);

        return 0;
}

/* --- File Operations --- */

static int ceu_open(struct file *file)
{
        struct ceu_device *ceudev = video_drvdata(file);
        int ret;

        ret = v4l2_fh_open(file);
        if (ret)
                return ret;

        mutex_lock(&ceudev->mlock);
        /* Causes soft-reset and sensor power on on first open */
        pm_runtime_get_sync(ceudev->dev);
        mutex_unlock(&ceudev->mlock);

        return 0;
}

static int ceu_release(struct file *file)
{
        struct ceu_device *ceudev = video_drvdata(file);

        vb2_fop_release(file);

        mutex_lock(&ceudev->mlock);
        /* Causes soft-reset and sensor power down on last close */
        pm_runtime_put(ceudev->dev);
        mutex_unlock(&ceudev->mlock);

        return 0;
}

static const struct v4l2_file_operations ceu_fops = {
        .owner                  = THIS_MODULE,
        .open                   = ceu_open,
        .release                = ceu_release,
        .unlocked_ioctl         = video_ioctl2,
        .mmap                   = vb2_fop_mmap,
        .poll                   = vb2_fop_poll,
};

/* --- Video Device IOCTLs --- */

static int ceu_querycap(struct file *file, void *priv,
                        struct v4l2_capability *cap)
{
        struct ceu_device *ceudev = video_drvdata(file);

        strscpy(cap->card, "Renesas CEU", sizeof(cap->card));
        strscpy(cap->driver, DRIVER_NAME, sizeof(cap->driver));
        snprintf(cap->bus_info, sizeof(cap->bus_info),
                 "platform:renesas-ceu-%s", dev_name(ceudev->dev));

        return 0;
}

static int ceu_enum_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_fmtdesc *f)
{
        const struct ceu_fmt *fmt;

        if (f->index >= ARRAY_SIZE(ceu_fmt_list))
                return -EINVAL;

        fmt = &ceu_fmt_list[f->index];
        f->pixelformat = fmt->fourcc;

        return 0;
}

static int ceu_try_fmt_vid_cap(struct file *file, void *priv,
                               struct v4l2_format *f)
{
        struct ceu_device *ceudev = video_drvdata(file);

        return ceu_try_fmt(ceudev, f);
}

static int ceu_s_fmt_vid_cap(struct file *file, void *priv,
                             struct v4l2_format *f)
{
        struct ceu_device *ceudev = video_drvdata(file);

        if (vb2_is_streaming(&ceudev->vb2_vq))
                return -EBUSY;

        return ceu_set_fmt(ceudev, f);
}

static int ceu_g_fmt_vid_cap(struct file *file, void *priv,
                             struct v4l2_format *f)
{
        struct ceu_device *ceudev = video_drvdata(file);

        f->fmt.pix_mp = ceudev->v4l2_pix;

        return 0;
}

static int ceu_enum_input(struct file *file, void *priv,
                          struct v4l2_input *inp)
{
        struct ceu_device *ceudev = video_drvdata(file);
        struct ceu_subdev *ceusd;

        if (inp->index >= ceudev->num_sd)
                return -EINVAL;

        ceusd = ceudev->subdevs[inp->index];

        inp->type = V4L2_INPUT_TYPE_CAMERA;
        inp->std = 0;
        snprintf(inp->name, sizeof(inp->name), "Camera%u: %s",
                 inp->index, ceusd->v4l2_sd->name);

        return 0;
}

static int ceu_g_input(struct file *file, void *priv, unsigned int *i)
{
        struct ceu_device *ceudev = video_drvdata(file);

        *i = ceudev->sd_index;

        return 0;
}

static int ceu_s_input(struct file *file, void *priv, unsigned int i)
{
        struct ceu_device *ceudev = video_drvdata(file);
        struct ceu_subdev *ceu_sd_old;
        int ret;

        if (i >= ceudev->num_sd)
                return -EINVAL;

        if (vb2_is_streaming(&ceudev->vb2_vq))
                return -EBUSY;

        if (i == ceudev->sd_index)
                return 0;

        ceu_sd_old = ceudev->sd;
        ceudev->sd = ceudev->subdevs[i];

        /*
         * Make sure we can generate output image formats and apply
         * default one.
         */
        ret = ceu_init_mbus_fmt(ceudev);
        if (ret) {
                ceudev->sd = ceu_sd_old;
                return -EINVAL;
        }

        ret = ceu_set_default_fmt(ceudev);
        if (ret) {
                ceudev->sd = ceu_sd_old;
                return -EINVAL;
        }

        /* Now that we're sure we can use the sensor, power off the old one. */
        v4l2_subdev_call(ceu_sd_old->v4l2_sd, core, s_power, 0);
        v4l2_subdev_call(ceudev->sd->v4l2_sd, core, s_power, 1);

        ceudev->sd_index = i;

        return 0;
}

static int ceu_g_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
{
        struct ceu_device *ceudev = video_drvdata(file);

        return v4l2_g_parm_cap(video_devdata(file), ceudev->sd->v4l2_sd, a);
}

static int ceu_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
{
        struct ceu_device *ceudev = video_drvdata(file);

        return v4l2_s_parm_cap(video_devdata(file), ceudev->sd->v4l2_sd, a);
}

static int ceu_enum_framesizes(struct file *file, void *fh,
                               struct v4l2_frmsizeenum *fsize)
{
        struct ceu_device *ceudev = video_drvdata(file);
        struct ceu_subdev *ceu_sd = ceudev->sd;
        const struct ceu_fmt *ceu_fmt;
        struct v4l2_subdev *v4l2_sd = ceu_sd->v4l2_sd;
        int ret;

        struct v4l2_subdev_frame_size_enum fse = {
                .code   = ceu_sd->mbus_fmt.mbus_code,
                .index  = fsize->index,
                .which  = V4L2_SUBDEV_FORMAT_ACTIVE,
        };

        /* Just check if user supplied pixel format is supported. */
        ceu_fmt = get_ceu_fmt_from_fourcc(fsize->pixel_format);
        if (!ceu_fmt)
                return -EINVAL;

        ret = v4l2_subdev_call(v4l2_sd, pad, enum_frame_size,
                               NULL, &fse);
        if (ret)
                return ret;

        fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
        fsize->discrete.width = CEU_W_MAX(fse.max_width);
        fsize->discrete.height = CEU_H_MAX(fse.max_height);

        return 0;
}

static int ceu_enum_frameintervals(struct file *file, void *fh,
                                   struct v4l2_frmivalenum *fival)
{
        struct ceu_device *ceudev = video_drvdata(file);
        struct ceu_subdev *ceu_sd = ceudev->sd;
        const struct ceu_fmt *ceu_fmt;
        struct v4l2_subdev *v4l2_sd = ceu_sd->v4l2_sd;
        int ret;

        struct v4l2_subdev_frame_interval_enum fie = {
                .code   = ceu_sd->mbus_fmt.mbus_code,
                .index = fival->index,
                .width = fival->width,
                .height = fival->height,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };

        /* Just check if user supplied pixel format is supported. */
        ceu_fmt = get_ceu_fmt_from_fourcc(fival->pixel_format);
        if (!ceu_fmt)
                return -EINVAL;

        ret = v4l2_subdev_call(v4l2_sd, pad, enum_frame_interval, NULL,
                               &fie);
        if (ret)
                return ret;

        fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
        fival->discrete = fie.interval;

        return 0;
}

static const struct v4l2_ioctl_ops ceu_ioctl_ops = {
        .vidioc_querycap                = ceu_querycap,

        .vidioc_enum_fmt_vid_cap        = ceu_enum_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap_mplane  = ceu_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap_mplane    = ceu_s_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap_mplane    = ceu_g_fmt_vid_cap,

        .vidioc_enum_input              = ceu_enum_input,
        .vidioc_g_input                 = ceu_g_input,
        .vidioc_s_input                 = ceu_s_input,

        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_expbuf                  = vb2_ioctl_expbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,

        .vidioc_g_parm                  = ceu_g_parm,
        .vidioc_s_parm                  = ceu_s_parm,
        .vidioc_enum_framesizes         = ceu_enum_framesizes,
        .vidioc_enum_frameintervals     = ceu_enum_frameintervals,

        .vidioc_log_status              = v4l2_ctrl_log_status,
        .vidioc_subscribe_event         = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
};

/*
 * ceu_vdev_release() - release CEU video device memory when last reference
 *                      to this driver is closed
 */
static void ceu_vdev_release(struct video_device *vdev)
{
        struct ceu_device *ceudev = video_get_drvdata(vdev);

        kfree(ceudev);
}

static int ceu_notify_bound(struct v4l2_async_notifier *notifier,
                            struct v4l2_subdev *v4l2_sd,
                            struct v4l2_async_subdev *asd)
{
        struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
        struct ceu_device *ceudev = v4l2_to_ceu(v4l2_dev);
        struct ceu_subdev *ceu_sd = to_ceu_subdev(asd);

        ceu_sd->v4l2_sd = v4l2_sd;
        ceudev->num_sd++;

        return 0;
}

static int ceu_notify_complete(struct v4l2_async_notifier *notifier)
{
        struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
        struct ceu_device *ceudev = v4l2_to_ceu(v4l2_dev);
        struct video_device *vdev = &ceudev->vdev;
        struct vb2_queue *q = &ceudev->vb2_vq;
        struct v4l2_subdev *v4l2_sd;
        int ret;

        /* Initialize vb2 queue. */
        q->type                 = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
        q->io_modes             = VB2_MMAP | VB2_DMABUF;
        q->drv_priv             = ceudev;
        q->ops                  = &ceu_vb2_ops;
        q->mem_ops              = &vb2_dma_contig_memops;
        q->buf_struct_size      = sizeof(struct ceu_buffer);
        q->timestamp_flags      = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        q->min_buffers_needed   = 2;
        q->lock                 = &ceudev->mlock;
        q->dev                  = ceudev->v4l2_dev.dev;

        ret = vb2_queue_init(q);
        if (ret)
                return ret;

        /*
         * Make sure at least one sensor is primary and use it to initialize
         * ceu formats.
         */
        if (!ceudev->sd) {
                ceudev->sd = ceudev->subdevs[0];
                ceudev->sd_index = 0;
        }

        v4l2_sd = ceudev->sd->v4l2_sd;

        ret = ceu_init_mbus_fmt(ceudev);
        if (ret)
                return ret;

        ret = ceu_set_default_fmt(ceudev);
        if (ret)
                return ret;

        /* Register the video device. */
        strscpy(vdev->name, DRIVER_NAME, sizeof(vdev->name));
        vdev->v4l2_dev          = v4l2_dev;
        vdev->lock              = &ceudev->mlock;
        vdev->queue             = &ceudev->vb2_vq;
        vdev->ctrl_handler      = v4l2_sd->ctrl_handler;
        vdev->fops              = &ceu_fops;
        vdev->ioctl_ops         = &ceu_ioctl_ops;
        vdev->release           = ceu_vdev_release;
        vdev->device_caps       = V4L2_CAP_VIDEO_CAPTURE_MPLANE |
                                  V4L2_CAP_STREAMING;
        video_set_drvdata(vdev, ceudev);

        ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
        if (ret < 0) {
                v4l2_err(vdev->v4l2_dev,
                         "video_register_device failed: %d\n", ret);
                return ret;
        }

        return 0;
}

static const struct v4l2_async_notifier_operations ceu_notify_ops = {
        .bound          = ceu_notify_bound,
        .complete       = ceu_notify_complete,
};

/*
 * ceu_init_async_subdevs() - Initialize CEU subdevices and async_subdevs in
 *                           ceu device. Both DT and platform data parsing use
 *                           this routine.
 *
 * Returns 0 for success, -ENOMEM for failure.
 */
static int ceu_init_async_subdevs(struct ceu_device *ceudev, unsigned int n_sd)
{
        /* Reserve memory for 'n_sd' ceu_subdev descriptors. */
        ceudev->subdevs = devm_kcalloc(ceudev->dev, n_sd,
                                       sizeof(*ceudev->subdevs), GFP_KERNEL);
        if (!ceudev->subdevs)
                return -ENOMEM;

        ceudev->sd = NULL;
        ceudev->sd_index = 0;
        ceudev->num_sd = 0;

        return 0;
}

/*
 * ceu_parse_platform_data() - Initialize async_subdevices using platform
 *                             device provided data.
 */
static int ceu_parse_platform_data(struct ceu_device *ceudev,
                                   const struct ceu_platform_data *pdata)
{
        const struct ceu_async_subdev *async_sd;
        struct ceu_subdev *ceu_sd;
        unsigned int i;
        int ret;

        if (pdata->num_subdevs == 0)
                return -ENODEV;

        ret = ceu_init_async_subdevs(ceudev, pdata->num_subdevs);
        if (ret)
                return ret;

        for (i = 0; i < pdata->num_subdevs; i++) {

                /* Setup the ceu subdevice and the async subdevice. */
                async_sd = &pdata->subdevs[i];
                ceu_sd = v4l2_async_notifier_add_i2c_subdev(&ceudev->notifier,
                                async_sd->i2c_adapter_id,
                                async_sd->i2c_address,
                                struct ceu_subdev);
                if (IS_ERR(ceu_sd)) {
                        v4l2_async_notifier_cleanup(&ceudev->notifier);
                        return PTR_ERR(ceu_sd);
                }
                ceu_sd->mbus_flags = async_sd->flags;
                ceudev->subdevs[i] = ceu_sd;
        }

        return pdata->num_subdevs;
}

/*
 * ceu_parse_dt() - Initialize async_subdevs parsing device tree graph.
 */
static int ceu_parse_dt(struct ceu_device *ceudev)
{
        struct device_node *of = ceudev->dev->of_node;
        struct device_node *ep;
        struct ceu_subdev *ceu_sd;
        unsigned int i;
        int num_ep;
        int ret;

        num_ep = of_graph_get_endpoint_count(of);
        if (!num_ep)
                return -ENODEV;

        ret = ceu_init_async_subdevs(ceudev, num_ep);
        if (ret)
                return ret;

        for (i = 0; i < num_ep; i++) {
                struct v4l2_fwnode_endpoint fw_ep = {
                        .bus_type = V4L2_MBUS_PARALLEL,
                        .bus = {
                                .parallel = {
                                        .flags = V4L2_MBUS_HSYNC_ACTIVE_HIGH |
                                                 V4L2_MBUS_VSYNC_ACTIVE_HIGH,
                                        .bus_width = 8,
                                },
                        },
                };

                ep = of_graph_get_endpoint_by_regs(of, 0, i);
                if (!ep) {
                        dev_err(ceudev->dev,
                                "No subdevice connected on endpoint %u.\n", i);
                        ret = -ENODEV;
                        goto error_cleanup;
                }

                ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &fw_ep);
                if (ret) {
                        dev_err(ceudev->dev,
                                "Unable to parse endpoint #%u: %d.\n", i, ret);
                        goto error_cleanup;
                }

                /* Setup the ceu subdevice and the async subdevice. */
                ceu_sd = v4l2_async_notifier_add_fwnode_remote_subdev(
                                &ceudev->notifier, of_fwnode_handle(ep),
                                struct ceu_subdev);
                if (IS_ERR(ceu_sd)) {
                        ret = PTR_ERR(ceu_sd);
                        goto error_cleanup;
                }
                ceu_sd->mbus_flags = fw_ep.bus.parallel.flags;
                ceudev->subdevs[i] = ceu_sd;

                of_node_put(ep);
        }

        return num_ep;

error_cleanup:
        v4l2_async_notifier_cleanup(&ceudev->notifier);
        of_node_put(ep);
        return ret;
}

/*
 * struct ceu_data - Platform specific CEU data
 * @irq_mask: CETCR mask with all interrupt sources enabled. The mask differs
 *            between SH4 and RZ platforms.
 */
struct ceu_data {
        u32 irq_mask;
};

static const struct ceu_data ceu_data_rz = {
        .irq_mask = CEU_CETCR_ALL_IRQS_RZ,
};

static const struct ceu_data ceu_data_sh4 = {
        .irq_mask = CEU_CETCR_ALL_IRQS_SH4,
};

#if IS_ENABLED(CONFIG_OF)
static const struct of_device_id ceu_of_match[] = {
        { .compatible = "renesas,r7s72100-ceu", .data = &ceu_data_rz },
        { .compatible = "renesas,r8a7740-ceu", .data = &ceu_data_rz },
        { }
};
MODULE_DEVICE_TABLE(of, ceu_of_match);
#endif

static int ceu_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        const struct ceu_data *ceu_data;
        struct ceu_device *ceudev;
        struct resource *res;
        unsigned int irq;
        int num_subdevs;
        int ret;

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

        platform_set_drvdata(pdev, ceudev);
        ceudev->dev = dev;

        INIT_LIST_HEAD(&ceudev->capture);
        spin_lock_init(&ceudev->lock);
        mutex_init(&ceudev->mlock);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        ceudev->base = devm_ioremap_resource(dev, res);
        if (IS_ERR(ceudev->base)) {
                ret = PTR_ERR(ceudev->base);
                goto error_free_ceudev;
        }

        ret = platform_get_irq(pdev, 0);
        if (ret < 0)
                goto error_free_ceudev;
        irq = ret;

        ret = devm_request_irq(dev, irq, ceu_irq,
                               0, dev_name(dev), ceudev);
        if (ret) {
                dev_err(&pdev->dev, "Unable to request CEU interrupt.\n");
                goto error_free_ceudev;
        }

        pm_runtime_enable(dev);

        ret = v4l2_device_register(dev, &ceudev->v4l2_dev);
        if (ret)
                goto error_pm_disable;

        v4l2_async_notifier_init(&ceudev->notifier);

        if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
                ceu_data = of_device_get_match_data(dev);
                num_subdevs = ceu_parse_dt(ceudev);
        } else if (dev->platform_data) {
                /* Assume SH4 if booting with platform data. */
                ceu_data = &ceu_data_sh4;
                num_subdevs = ceu_parse_platform_data(ceudev,
                                                      dev->platform_data);
        } else {
                num_subdevs = -EINVAL;
        }

        if (num_subdevs < 0) {
                ret = num_subdevs;
                goto error_v4l2_unregister;
        }
        ceudev->irq_mask = ceu_data->irq_mask;

        ceudev->notifier.v4l2_dev       = &ceudev->v4l2_dev;
        ceudev->notifier.ops            = &ceu_notify_ops;
        ret = v4l2_async_notifier_register(&ceudev->v4l2_dev,
                                           &ceudev->notifier);
        if (ret)
                goto error_cleanup;

        dev_info(dev, "Renesas Capture Engine Unit %s\n", dev_name(dev));

        return 0;

error_cleanup:
        v4l2_async_notifier_cleanup(&ceudev->notifier);
error_v4l2_unregister:
        v4l2_device_unregister(&ceudev->v4l2_dev);
error_pm_disable:
        pm_runtime_disable(dev);
error_free_ceudev:
        kfree(ceudev);

        return ret;
}

static int ceu_remove(struct platform_device *pdev)
{
        struct ceu_device *ceudev = platform_get_drvdata(pdev);

        pm_runtime_disable(ceudev->dev);

        v4l2_async_notifier_unregister(&ceudev->notifier);

        v4l2_async_notifier_cleanup(&ceudev->notifier);

        v4l2_device_unregister(&ceudev->v4l2_dev);

        video_unregister_device(&ceudev->vdev);

        return 0;
}

static const struct dev_pm_ops ceu_pm_ops = {
        SET_RUNTIME_PM_OPS(ceu_runtime_suspend,
                           ceu_runtime_resume,
                           NULL)
};

static struct platform_driver ceu_driver = {
        .driver         = {
                .name   = DRIVER_NAME,
                .pm     = &ceu_pm_ops,
                .of_match_table = of_match_ptr(ceu_of_match),
        },
        .probe          = ceu_probe,
        .remove         = ceu_remove,
};

module_platform_driver(ceu_driver);

MODULE_DESCRIPTION("Renesas CEU camera driver");
MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org>");
MODULE_LICENSE("GPL v2");