/*
 * sh-mobile VEU mem2mem driver
 *
 * Copyright (C) 2012 Renesas Electronics Corporation
 * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
 * Copyright (C) 2008 Magnus Damm
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License as
 * published by the Free Software Foundation
 */

#include <linux/err.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/videodev2.h>

#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-image-sizes.h>
#include <media/videobuf2-dma-contig.h>

#define VEU_STR 0x00 /* start register */
#define VEU_SWR 0x10 /* src: line length */
#define VEU_SSR 0x14 /* src: image size */
#define VEU_SAYR 0x18 /* src: y/rgb plane address */
#define VEU_SACR 0x1c /* src: c plane address */
#define VEU_BSSR 0x20 /* bundle mode register */
#define VEU_EDWR 0x30 /* dst: line length */
#define VEU_DAYR 0x34 /* dst: y/rgb plane address */
#define VEU_DACR 0x38 /* dst: c plane address */
#define VEU_TRCR 0x50 /* transform control */
#define VEU_RFCR 0x54 /* resize scale */
#define VEU_RFSR 0x58 /* resize clip */
#define VEU_ENHR 0x5c /* enhance */
#define VEU_FMCR 0x70 /* filter mode */
#define VEU_VTCR 0x74 /* lowpass vertical */
#define VEU_HTCR 0x78 /* lowpass horizontal */
#define VEU_APCR 0x80 /* color match */
#define VEU_ECCR 0x84 /* color replace */
#define VEU_AFXR 0x90 /* fixed mode */
#define VEU_SWPR 0x94 /* swap */
#define VEU_EIER 0xa0 /* interrupt mask */
#define VEU_EVTR 0xa4 /* interrupt event */
#define VEU_STAR 0xb0 /* status */
#define VEU_BSRR 0xb4 /* reset */

#define VEU_MCR00 0x200 /* color conversion matrix coefficient 00 */
#define VEU_MCR01 0x204 /* color conversion matrix coefficient 01 */
#define VEU_MCR02 0x208 /* color conversion matrix coefficient 02 */
#define VEU_MCR10 0x20c /* color conversion matrix coefficient 10 */
#define VEU_MCR11 0x210 /* color conversion matrix coefficient 11 */
#define VEU_MCR12 0x214 /* color conversion matrix coefficient 12 */
#define VEU_MCR20 0x218 /* color conversion matrix coefficient 20 */
#define VEU_MCR21 0x21c /* color conversion matrix coefficient 21 */
#define VEU_MCR22 0x220 /* color conversion matrix coefficient 22 */
#define VEU_COFFR 0x224 /* color conversion offset */
#define VEU_CBR   0x228 /* color conversion clip */

/*
 * 4092x4092 max size is the normal case. In some cases it can be reduced to
 * 2048x2048, in other cases it can be 4092x8188 or even 8188x8188.
 */
#define MAX_W 4092
#define MAX_H 4092
#define MIN_W 8
#define MIN_H 8
#define ALIGN_W 4

/* 3 buffers of 2048 x 1536 - 3 megapixels @ 16bpp */
#define VIDEO_MEM_LIMIT ALIGN(2048 * 1536 * 2 * 3, 1024 * 1024)

#define MEM2MEM_DEF_TRANSLEN 1

struct sh_veu_dev;

struct sh_veu_file {
        struct sh_veu_dev *veu_dev;
        bool cfg_needed;
};

struct sh_veu_format {
        char *name;
        u32 fourcc;
        unsigned int depth;
        unsigned int ydepth;
};

/* video data format */
struct sh_veu_vfmt {
        /* Replace with v4l2_rect */
        struct v4l2_rect                frame;
        unsigned int                    bytesperline;
        unsigned int                    offset_y;
        unsigned int                    offset_c;
        const struct sh_veu_format      *fmt;
};

struct sh_veu_dev {
        struct v4l2_device v4l2_dev;
        struct video_device vdev;
        struct v4l2_m2m_dev *m2m_dev;
        struct device *dev;
        struct v4l2_m2m_ctx *m2m_ctx;
        struct sh_veu_vfmt vfmt_out;
        struct sh_veu_vfmt vfmt_in;
        /* Only single user per direction so far */
        struct sh_veu_file *capture;
        struct sh_veu_file *output;
        struct mutex fop_lock;
        void __iomem *base;
        struct vb2_alloc_ctx *alloc_ctx;
        spinlock_t lock;
        bool is_2h;
        unsigned int xaction;
        bool aborting;
};

enum sh_veu_fmt_idx {
        SH_VEU_FMT_NV12,
        SH_VEU_FMT_NV16,
        SH_VEU_FMT_NV24,
        SH_VEU_FMT_RGB332,
        SH_VEU_FMT_RGB444,
        SH_VEU_FMT_RGB565,
        SH_VEU_FMT_RGB666,
        SH_VEU_FMT_RGB24,
};

#define DEFAULT_IN_WIDTH        VGA_WIDTH
#define DEFAULT_IN_HEIGHT       VGA_HEIGHT
#define DEFAULT_IN_FMTIDX       SH_VEU_FMT_NV12
#define DEFAULT_OUT_WIDTH       VGA_WIDTH
#define DEFAULT_OUT_HEIGHT      VGA_HEIGHT
#define DEFAULT_OUT_FMTIDX      SH_VEU_FMT_RGB565

/*
 * Alignment: Y-plane should be 4-byte aligned for NV12 and NV16, and 8-byte
 * aligned for NV24.
 */
static const struct sh_veu_format sh_veu_fmt[] = {
        [SH_VEU_FMT_NV12]   = { .ydepth = 8, .depth = 12, .name = "NV12", .fourcc = V4L2_PIX_FMT_NV12 },
        [SH_VEU_FMT_NV16]   = { .ydepth = 8, .depth = 16, .name = "NV16", .fourcc = V4L2_PIX_FMT_NV16 },
        [SH_VEU_FMT_NV24]   = { .ydepth = 8, .depth = 24, .name = "NV24", .fourcc = V4L2_PIX_FMT_NV24 },
        [SH_VEU_FMT_RGB332] = { .ydepth = 8, .depth = 8, .name = "RGB332", .fourcc = V4L2_PIX_FMT_RGB332 },
        [SH_VEU_FMT_RGB444] = { .ydepth = 16, .depth = 16, .name = "RGB444", .fourcc = V4L2_PIX_FMT_RGB444 },
        [SH_VEU_FMT_RGB565] = { .ydepth = 16, .depth = 16, .name = "RGB565", .fourcc = V4L2_PIX_FMT_RGB565 },
        [SH_VEU_FMT_RGB666] = { .ydepth = 32, .depth = 32, .name = "BGR666", .fourcc = V4L2_PIX_FMT_BGR666 },
        [SH_VEU_FMT_RGB24]  = { .ydepth = 24, .depth = 24, .name = "RGB24", .fourcc = V4L2_PIX_FMT_RGB24 },
};

#define DEFAULT_IN_VFMT (struct sh_veu_vfmt){                                           \
        .frame = {                                                                      \
                .width = VGA_WIDTH,                                                     \
                .height = VGA_HEIGHT,                                                   \
        },                                                                              \
        .bytesperline = (VGA_WIDTH * sh_veu_fmt[DEFAULT_IN_FMTIDX].ydepth) >> 3,        \
        .fmt = &sh_veu_fmt[DEFAULT_IN_FMTIDX],                                          \
}

#define DEFAULT_OUT_VFMT (struct sh_veu_vfmt){                                          \
        .frame = {                                                                      \
                .width = VGA_WIDTH,                                                     \
                .height = VGA_HEIGHT,                                                   \
        },                                                                              \
        .bytesperline = (VGA_WIDTH * sh_veu_fmt[DEFAULT_OUT_FMTIDX].ydepth) >> 3,       \
        .fmt = &sh_veu_fmt[DEFAULT_OUT_FMTIDX],                                         \
}

/*
 * TODO: add support for further output formats:
 *      SH_VEU_FMT_NV12,
 *      SH_VEU_FMT_NV16,
 *      SH_VEU_FMT_NV24,
 *      SH_VEU_FMT_RGB332,
 *      SH_VEU_FMT_RGB444,
 *      SH_VEU_FMT_RGB666,
 *      SH_VEU_FMT_RGB24,
 */

static const int sh_veu_fmt_out[] = {
        SH_VEU_FMT_RGB565,
};

/*
 * TODO: add support for further input formats:
 *      SH_VEU_FMT_NV16,
 *      SH_VEU_FMT_NV24,
 *      SH_VEU_FMT_RGB565,
 *      SH_VEU_FMT_RGB666,
 *      SH_VEU_FMT_RGB24,
 */
static const int sh_veu_fmt_in[] = {
        SH_VEU_FMT_NV12,
};

static enum v4l2_colorspace sh_veu_4cc2cspace(u32 fourcc)
{
        switch (fourcc) {
        default:
                BUG();
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV24:
                return V4L2_COLORSPACE_JPEG;
        case V4L2_PIX_FMT_RGB332:
        case V4L2_PIX_FMT_RGB444:
        case V4L2_PIX_FMT_RGB565:
        case V4L2_PIX_FMT_BGR666:
        case V4L2_PIX_FMT_RGB24:
                return V4L2_COLORSPACE_SRGB;
        }
}

static u32 sh_veu_reg_read(struct sh_veu_dev *veu, unsigned int reg)
{
        return ioread32(veu->base + reg);
}

static void sh_veu_reg_write(struct sh_veu_dev *veu, unsigned int reg,
                             u32 value)
{
        iowrite32(value, veu->base + reg);
}

                /* ========== mem2mem callbacks ========== */

static void sh_veu_job_abort(void *priv)
{
        struct sh_veu_dev *veu = priv;

        /* Will cancel the transaction in the next interrupt handler */
        veu->aborting = true;
}

static void sh_veu_process(struct sh_veu_dev *veu,
                           struct vb2_buffer *src_buf,
                           struct vb2_buffer *dst_buf)
{
        dma_addr_t addr = vb2_dma_contig_plane_dma_addr(dst_buf, 0);

        sh_veu_reg_write(veu, VEU_DAYR, addr + veu->vfmt_out.offset_y);
        sh_veu_reg_write(veu, VEU_DACR, veu->vfmt_out.offset_c ?
                         addr + veu->vfmt_out.offset_c : 0);
        dev_dbg(veu->dev, "%s(): dst base %lx, y: %x, c: %x\n", __func__,
                (unsigned long)addr,
                veu->vfmt_out.offset_y, veu->vfmt_out.offset_c);

        addr = vb2_dma_contig_plane_dma_addr(src_buf, 0);
        sh_veu_reg_write(veu, VEU_SAYR, addr + veu->vfmt_in.offset_y);
        sh_veu_reg_write(veu, VEU_SACR, veu->vfmt_in.offset_c ?
                         addr + veu->vfmt_in.offset_c : 0);
        dev_dbg(veu->dev, "%s(): src base %lx, y: %x, c: %x\n", __func__,
                (unsigned long)addr,
                veu->vfmt_in.offset_y, veu->vfmt_in.offset_c);

        sh_veu_reg_write(veu, VEU_STR, 1);

        sh_veu_reg_write(veu, VEU_EIER, 1); /* enable interrupt in VEU */
}

/**
 * sh_veu_device_run() - prepares and starts the device
 *
 * This will be called by the framework when it decides to schedule a particular
 * instance.
 */
static void sh_veu_device_run(void *priv)
{
        struct sh_veu_dev *veu = priv;
        struct vb2_buffer *src_buf, *dst_buf;

        src_buf = v4l2_m2m_next_src_buf(veu->m2m_ctx);
        dst_buf = v4l2_m2m_next_dst_buf(veu->m2m_ctx);

        if (src_buf && dst_buf)
                sh_veu_process(veu, src_buf, dst_buf);
}

                /* ========== video ioctls ========== */

static bool sh_veu_is_streamer(struct sh_veu_dev *veu, struct sh_veu_file *veu_file,
                               enum v4l2_buf_type type)
{
        return (type == V4L2_BUF_TYPE_VIDEO_CAPTURE &&
                veu_file == veu->capture) ||
                (type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
                 veu_file == veu->output);
}

static int sh_veu_queue_init(void *priv, struct vb2_queue *src_vq,
                             struct vb2_queue *dst_vq);

/*
 * It is not unusual to have video nodes open()ed multiple times. While some
 * V4L2 operations are non-intrusive, like querying formats and various
 * parameters, others, like setting formats, starting and stopping streaming,
 * queuing and dequeuing buffers, directly affect hardware configuration and /
 * or execution. This function verifies availability of the requested interface
 * and, if available, reserves it for the requesting user.
 */
static int sh_veu_stream_init(struct sh_veu_dev *veu, struct sh_veu_file *veu_file,
                              enum v4l2_buf_type type)
{
        struct sh_veu_file **stream;

        switch (type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
                stream = &veu->capture;
                break;
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
                stream = &veu->output;
                break;
        default:
                return -EINVAL;
        }

        if (*stream == veu_file)
                return 0;

        if (*stream)
                return -EBUSY;

        *stream = veu_file;

        return 0;
}

static int sh_veu_context_init(struct sh_veu_dev *veu)
{
        if (veu->m2m_ctx)
                return 0;

        veu->m2m_ctx = v4l2_m2m_ctx_init(veu->m2m_dev, veu,
                                         sh_veu_queue_init);

        return PTR_ERR_OR_ZERO(veu->m2m_ctx);
}

static int sh_veu_querycap(struct file *file, void *priv,
                           struct v4l2_capability *cap)
{
        strlcpy(cap->driver, "sh-veu", sizeof(cap->driver));
        strlcpy(cap->card, "sh-mobile VEU", sizeof(cap->card));
        strlcpy(cap->bus_info, "platform:sh-veu", sizeof(cap->bus_info));
        cap->device_caps = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
        cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

        return 0;
}

static int sh_veu_enum_fmt(struct v4l2_fmtdesc *f, const int *fmt, int fmt_num)
{
        if (f->index >= fmt_num)
                return -EINVAL;

        strlcpy(f->description, sh_veu_fmt[fmt[f->index]].name, sizeof(f->description));
        f->pixelformat = sh_veu_fmt[fmt[f->index]].fourcc;
        return 0;
}

static int sh_veu_enum_fmt_vid_cap(struct file *file, void *priv,
                                   struct v4l2_fmtdesc *f)
{
        return sh_veu_enum_fmt(f, sh_veu_fmt_out, ARRAY_SIZE(sh_veu_fmt_out));
}

static int sh_veu_enum_fmt_vid_out(struct file *file, void *priv,
                                   struct v4l2_fmtdesc *f)
{
        return sh_veu_enum_fmt(f, sh_veu_fmt_in, ARRAY_SIZE(sh_veu_fmt_in));
}

static struct sh_veu_vfmt *sh_veu_get_vfmt(struct sh_veu_dev *veu,
                                           enum v4l2_buf_type type)
{
        switch (type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
                return &veu->vfmt_out;
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
                return &veu->vfmt_in;
        default:
                return NULL;
        }
}

static int sh_veu_g_fmt(struct sh_veu_file *veu_file, struct v4l2_format *f)
{
        struct v4l2_pix_format *pix = &f->fmt.pix;
        struct sh_veu_dev *veu = veu_file->veu_dev;
        struct sh_veu_vfmt *vfmt;

        vfmt = sh_veu_get_vfmt(veu, f->type);

        pix->width              = vfmt->frame.width;
        pix->height             = vfmt->frame.height;
        pix->field              = V4L2_FIELD_NONE;
        pix->pixelformat        = vfmt->fmt->fourcc;
        pix->colorspace         = sh_veu_4cc2cspace(pix->pixelformat);
        pix->bytesperline       = vfmt->bytesperline;
        pix->sizeimage          = vfmt->bytesperline * pix->height *
                vfmt->fmt->depth / vfmt->fmt->ydepth;
        dev_dbg(veu->dev, "%s(): type: %d, size %u @ %ux%u, fmt %x\n", __func__,
                f->type, pix->sizeimage, pix->width, pix->height, pix->pixelformat);

        return 0;
}

static int sh_veu_g_fmt_vid_out(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        return sh_veu_g_fmt(priv, f);
}

static int sh_veu_g_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        return sh_veu_g_fmt(priv, f);
}

static int sh_veu_try_fmt(struct v4l2_format *f, const struct sh_veu_format *fmt)
{
        struct v4l2_pix_format *pix = &f->fmt.pix;
        unsigned int y_bytes_used;

        /*
         * V4L2 specification suggests, that the driver should correct the
         * format struct if any of the dimensions is unsupported
         */
        switch (pix->field) {
        default:
        case V4L2_FIELD_ANY:
                pix->field = V4L2_FIELD_NONE;
                /* fall through: continue handling V4L2_FIELD_NONE */
        case V4L2_FIELD_NONE:
                break;
        }

        v4l_bound_align_image(&pix->width, MIN_W, MAX_W, ALIGN_W,
                              &pix->height, MIN_H, MAX_H, 0, 0);

        y_bytes_used = (pix->width * fmt->ydepth) >> 3;

        if (pix->bytesperline < y_bytes_used)
                pix->bytesperline = y_bytes_used;
        pix->sizeimage = pix->height * pix->bytesperline * fmt->depth / fmt->ydepth;

        pix->pixelformat        = fmt->fourcc;
        pix->colorspace         = sh_veu_4cc2cspace(pix->pixelformat);

        pr_debug("%s(): type: %d, size %u\n", __func__, f->type, pix->sizeimage);

        return 0;
}

static const struct sh_veu_format *sh_veu_find_fmt(const struct v4l2_format *f)
{
        const int *fmt;
        int i, n, dflt;

        pr_debug("%s(%d;%d)\n", __func__, f->type, f->fmt.pix.field);

        switch (f->type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
                fmt = sh_veu_fmt_out;
                n = ARRAY_SIZE(sh_veu_fmt_out);
                dflt = DEFAULT_OUT_FMTIDX;
                break;
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
        default:
                fmt = sh_veu_fmt_in;
                n = ARRAY_SIZE(sh_veu_fmt_in);
                dflt = DEFAULT_IN_FMTIDX;
                break;
        }

        for (i = 0; i < n; i++)
                if (sh_veu_fmt[fmt[i]].fourcc == f->fmt.pix.pixelformat)
                        return &sh_veu_fmt[fmt[i]];

        return &sh_veu_fmt[dflt];
}

static int sh_veu_try_fmt_vid_cap(struct file *file, void *priv,
                                  struct v4l2_format *f)
{
        const struct sh_veu_format *fmt;

        fmt = sh_veu_find_fmt(f);
        if (!fmt)
                /* wrong buffer type */
                return -EINVAL;

        return sh_veu_try_fmt(f, fmt);
}

static int sh_veu_try_fmt_vid_out(struct file *file, void *priv,
                                  struct v4l2_format *f)
{
        const struct sh_veu_format *fmt;

        fmt = sh_veu_find_fmt(f);
        if (!fmt)
                /* wrong buffer type */
                return -EINVAL;

        return sh_veu_try_fmt(f, fmt);
}

static void sh_veu_colour_offset(struct sh_veu_dev *veu, struct sh_veu_vfmt *vfmt)
{
        /* dst_left and dst_top validity will be verified in CROP / COMPOSE */
        unsigned int left = vfmt->frame.left & ~0x03;
        unsigned int top = vfmt->frame.top;
        dma_addr_t offset = ((left * veu->vfmt_out.fmt->depth) >> 3) +
                top * veu->vfmt_out.bytesperline;
        unsigned int y_line;

        vfmt->offset_y = offset;

        switch (vfmt->fmt->fourcc) {
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV24:
                y_line = ALIGN(vfmt->frame.width, 16);
                vfmt->offset_c = offset + y_line * vfmt->frame.height;
                break;
        case V4L2_PIX_FMT_RGB332:
        case V4L2_PIX_FMT_RGB444:
        case V4L2_PIX_FMT_RGB565:
        case V4L2_PIX_FMT_BGR666:
        case V4L2_PIX_FMT_RGB24:
                vfmt->offset_c = 0;
                break;
        default:
                BUG();
        }
}

static int sh_veu_s_fmt(struct sh_veu_file *veu_file, struct v4l2_format *f)
{
        struct v4l2_pix_format *pix = &f->fmt.pix;
        struct sh_veu_dev *veu = veu_file->veu_dev;
        struct sh_veu_vfmt *vfmt;
        struct vb2_queue *vq;
        int ret = sh_veu_context_init(veu);
        if (ret < 0)
                return ret;

        vq = v4l2_m2m_get_vq(veu->m2m_ctx, f->type);
        if (!vq)
                return -EINVAL;

        if (vb2_is_busy(vq)) {
                v4l2_err(&veu_file->veu_dev->v4l2_dev, "%s queue busy\n", __func__);
                return -EBUSY;
        }

        vfmt = sh_veu_get_vfmt(veu, f->type);
        /* called after try_fmt(), hence vfmt != NULL. Implicit BUG_ON() below */

        vfmt->fmt               = sh_veu_find_fmt(f);
        /* vfmt->fmt != NULL following the same argument as above */
        vfmt->frame.width       = pix->width;
        vfmt->frame.height      = pix->height;
        vfmt->bytesperline      = pix->bytesperline;

        sh_veu_colour_offset(veu, vfmt);

        /*
         * We could also verify and require configuration only if any parameters
         * actually have changed, but it is unlikely, that the user requests the
         * same configuration several times without closing the device.
         */
        veu_file->cfg_needed = true;

        dev_dbg(veu->dev,
                "Setting format for type %d, wxh: %dx%d, fmt: %x\n",
                f->type, pix->width, pix->height, vfmt->fmt->fourcc);

        return 0;
}

static int sh_veu_s_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        int ret = sh_veu_try_fmt_vid_cap(file, priv, f);
        if (ret)
                return ret;

        return sh_veu_s_fmt(priv, f);
}

static int sh_veu_s_fmt_vid_out(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        int ret = sh_veu_try_fmt_vid_out(file, priv, f);
        if (ret)
                return ret;

        return sh_veu_s_fmt(priv, f);
}

static int sh_veu_reqbufs(struct file *file, void *priv,
                          struct v4l2_requestbuffers *reqbufs)
{
        struct sh_veu_file *veu_file = priv;
        struct sh_veu_dev *veu = veu_file->veu_dev;
        int ret = sh_veu_context_init(veu);
        if (ret < 0)
                return ret;

        ret = sh_veu_stream_init(veu, veu_file, reqbufs->type);
        if (ret < 0)
                return ret;

        return v4l2_m2m_reqbufs(file, veu->m2m_ctx, reqbufs);
}

static int sh_veu_querybuf(struct file *file, void *priv,
                           struct v4l2_buffer *buf)
{
        struct sh_veu_file *veu_file = priv;

        if (!sh_veu_is_streamer(veu_file->veu_dev, veu_file, buf->type))
                return -EBUSY;

        return v4l2_m2m_querybuf(file, veu_file->veu_dev->m2m_ctx, buf);
}

static int sh_veu_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
        struct sh_veu_file *veu_file = priv;

        dev_dbg(veu_file->veu_dev->dev, "%s(%d)\n", __func__, buf->type);
        if (!sh_veu_is_streamer(veu_file->veu_dev, veu_file, buf->type))
                return -EBUSY;

        return v4l2_m2m_qbuf(file, veu_file->veu_dev->m2m_ctx, buf);
}

static int sh_veu_dqbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
        struct sh_veu_file *veu_file = priv;

        dev_dbg(veu_file->veu_dev->dev, "%s(%d)\n", __func__, buf->type);
        if (!sh_veu_is_streamer(veu_file->veu_dev, veu_file, buf->type))
                return -EBUSY;

        return v4l2_m2m_dqbuf(file, veu_file->veu_dev->m2m_ctx, buf);
}

static void sh_veu_calc_scale(struct sh_veu_dev *veu,
                              int size_in, int size_out, int crop_out,
                              u32 *mant, u32 *frac, u32 *rep)
{
        u32 fixpoint;

        /* calculate FRAC and MANT */
        *rep = *mant = *frac = 0;

        if (size_in == size_out) {
                if (crop_out != size_out)
                        *mant = 1; /* needed for cropping */
                return;
        }

        /* VEU2H special upscale */
        if (veu->is_2h && size_out > size_in) {
                u32 fixpoint = (4096 * size_in) / size_out;
                *mant = fixpoint / 4096;
                *frac = (fixpoint - (*mant * 4096)) & ~0x07;

                switch (*frac) {
                case 0x800:
                        *rep = 1;
                        break;
                case 0x400:
                        *rep = 3;
                        break;
                case 0x200:
                        *rep = 7;
                        break;
                }
                if (*rep)
                        return;
        }

        fixpoint = (4096 * (size_in - 1)) / (size_out + 1);
        *mant = fixpoint / 4096;
        *frac = fixpoint - (*mant * 4096);

        if (*frac & 0x07) {
                /*
                 * FIXME: do we really have to round down twice in the
                 * up-scaling case?
                 */
                *frac &= ~0x07;
                if (size_out > size_in)
                        *frac -= 8; /* round down if scaling up */
                else
                        *frac += 8; /* round up if scaling down */
        }
}

static unsigned long sh_veu_scale_v(struct sh_veu_dev *veu,
                                    int size_in, int size_out, int crop_out)
{
        u32 mant, frac, value, rep;

        sh_veu_calc_scale(veu, size_in, size_out, crop_out, &mant, &frac, &rep);

        /* set scale */
        value = (sh_veu_reg_read(veu, VEU_RFCR) & ~0xffff0000) |
                (((mant << 12) | frac) << 16);

        sh_veu_reg_write(veu, VEU_RFCR, value);

        /* set clip */
        value = (sh_veu_reg_read(veu, VEU_RFSR) & ~0xffff0000) |
                (((rep << 12) | crop_out) << 16);

        sh_veu_reg_write(veu, VEU_RFSR, value);

        return ALIGN((size_in * crop_out) / size_out, 4);
}

static unsigned long sh_veu_scale_h(struct sh_veu_dev *veu,
                                    int size_in, int size_out, int crop_out)
{
        u32 mant, frac, value, rep;

        sh_veu_calc_scale(veu, size_in, size_out, crop_out, &mant, &frac, &rep);

        /* set scale */
        value = (sh_veu_reg_read(veu, VEU_RFCR) & ~0xffff) |
                (mant << 12) | frac;

        sh_veu_reg_write(veu, VEU_RFCR, value);

        /* set clip */
        value = (sh_veu_reg_read(veu, VEU_RFSR) & ~0xffff) |
                (rep << 12) | crop_out;

        sh_veu_reg_write(veu, VEU_RFSR, value);

        return ALIGN((size_in * crop_out) / size_out, 4);
}

static void sh_veu_configure(struct sh_veu_dev *veu)
{
        u32 src_width, src_stride, src_height;
        u32 dst_width, dst_stride, dst_height;
        u32 real_w, real_h;

        /* reset VEU */
        sh_veu_reg_write(veu, VEU_BSRR, 0x100);

        src_width = veu->vfmt_in.frame.width;
        src_height = veu->vfmt_in.frame.height;
        src_stride = ALIGN(veu->vfmt_in.frame.width, 16);

        dst_width = real_w = veu->vfmt_out.frame.width;
        dst_height = real_h = veu->vfmt_out.frame.height;
        /* Datasheet is unclear - whether it's always number of bytes or not */
        dst_stride = veu->vfmt_out.bytesperline;

        /*
         * So far real_w == dst_width && real_h == dst_height, but it wasn't
         * necessarily the case in the original vidix driver, so, it may change
         * here in the future too.
         */
        src_width = sh_veu_scale_h(veu, src_width, real_w, dst_width);
        src_height = sh_veu_scale_v(veu, src_height, real_h, dst_height);

        sh_veu_reg_write(veu, VEU_SWR, src_stride);
        sh_veu_reg_write(veu, VEU_SSR, src_width | (src_height << 16));
        sh_veu_reg_write(veu, VEU_BSSR, 0); /* not using bundle mode */

        sh_veu_reg_write(veu, VEU_EDWR, dst_stride);
        sh_veu_reg_write(veu, VEU_DACR, 0); /* unused for RGB */

        sh_veu_reg_write(veu, VEU_SWPR, 0x67);
        sh_veu_reg_write(veu, VEU_TRCR, (6 << 16) | (0 << 14) | 2 | 4);

        if (veu->is_2h) {
                sh_veu_reg_write(veu, VEU_MCR00, 0x0cc5);
                sh_veu_reg_write(veu, VEU_MCR01, 0x0950);
                sh_veu_reg_write(veu, VEU_MCR02, 0x0000);

                sh_veu_reg_write(veu, VEU_MCR10, 0x397f);
                sh_veu_reg_write(veu, VEU_MCR11, 0x0950);
                sh_veu_reg_write(veu, VEU_MCR12, 0x3ccd);

                sh_veu_reg_write(veu, VEU_MCR20, 0x0000);
                sh_veu_reg_write(veu, VEU_MCR21, 0x0950);
                sh_veu_reg_write(veu, VEU_MCR22, 0x1023);

                sh_veu_reg_write(veu, VEU_COFFR, 0x00800010);
        }
}

static int sh_veu_streamon(struct file *file, void *priv,
                           enum v4l2_buf_type type)
{
        struct sh_veu_file *veu_file = priv;

        if (!sh_veu_is_streamer(veu_file->veu_dev, veu_file, type))
                return -EBUSY;

        if (veu_file->cfg_needed) {
                struct sh_veu_dev *veu = veu_file->veu_dev;
                veu_file->cfg_needed = false;
                sh_veu_configure(veu_file->veu_dev);
                veu->xaction = 0;
                veu->aborting = false;
        }

        return v4l2_m2m_streamon(file, veu_file->veu_dev->m2m_ctx, type);
}

static int sh_veu_streamoff(struct file *file, void *priv,
                            enum v4l2_buf_type type)
{
        struct sh_veu_file *veu_file = priv;

        if (!sh_veu_is_streamer(veu_file->veu_dev, veu_file, type))
                return -EBUSY;

        return v4l2_m2m_streamoff(file, veu_file->veu_dev->m2m_ctx, type);
}

static const struct v4l2_ioctl_ops sh_veu_ioctl_ops = {
        .vidioc_querycap        = sh_veu_querycap,

        .vidioc_enum_fmt_vid_cap = sh_veu_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap   = sh_veu_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap = sh_veu_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap   = sh_veu_s_fmt_vid_cap,

        .vidioc_enum_fmt_vid_out = sh_veu_enum_fmt_vid_out,
        .vidioc_g_fmt_vid_out   = sh_veu_g_fmt_vid_out,
        .vidioc_try_fmt_vid_out = sh_veu_try_fmt_vid_out,
        .vidioc_s_fmt_vid_out   = sh_veu_s_fmt_vid_out,

        .vidioc_reqbufs         = sh_veu_reqbufs,
        .vidioc_querybuf        = sh_veu_querybuf,

        .vidioc_qbuf            = sh_veu_qbuf,
        .vidioc_dqbuf           = sh_veu_dqbuf,

        .vidioc_streamon        = sh_veu_streamon,
        .vidioc_streamoff       = sh_veu_streamoff,
};

                /* ========== Queue operations ========== */

static int sh_veu_queue_setup(struct vb2_queue *vq,
                              const struct v4l2_format *f,
                              unsigned int *nbuffers, unsigned int *nplanes,
                              unsigned int sizes[], void *alloc_ctxs[])
{
        struct sh_veu_dev *veu = vb2_get_drv_priv(vq);
        struct sh_veu_vfmt *vfmt;
        unsigned int size, count = *nbuffers;

        if (f) {
                const struct v4l2_pix_format *pix = &f->fmt.pix;
                const struct sh_veu_format *fmt = sh_veu_find_fmt(f);
                struct v4l2_format ftmp = *f;

                if (fmt->fourcc != pix->pixelformat)
                        return -EINVAL;
                sh_veu_try_fmt(&ftmp, fmt);
                if (ftmp.fmt.pix.width != pix->width ||
                    ftmp.fmt.pix.height != pix->height)
                        return -EINVAL;
                size = pix->bytesperline ? pix->bytesperline * pix->height * fmt->depth / fmt->ydepth :
                        pix->width * pix->height * fmt->depth / fmt->ydepth;
        } else {
                vfmt = sh_veu_get_vfmt(veu, vq->type);
                size = vfmt->bytesperline * vfmt->frame.height * vfmt->fmt->depth / vfmt->fmt->ydepth;
        }

        if (count < 2)
                *nbuffers = count = 2;

        if (size * count > VIDEO_MEM_LIMIT) {
                count = VIDEO_MEM_LIMIT / size;
                *nbuffers = count;
        }

        *nplanes = 1;
        sizes[0] = size;
        alloc_ctxs[0] = veu->alloc_ctx;

        dev_dbg(veu->dev, "get %d buffer(s) of size %d each.\n", count, size);

        return 0;
}

static int sh_veu_buf_prepare(struct vb2_buffer *vb)
{
        struct sh_veu_dev *veu = vb2_get_drv_priv(vb->vb2_queue);
        struct sh_veu_vfmt *vfmt;
        unsigned int sizeimage;

        vfmt = sh_veu_get_vfmt(veu, vb->vb2_queue->type);
        sizeimage = vfmt->bytesperline * vfmt->frame.height *
                vfmt->fmt->depth / vfmt->fmt->ydepth;

        if (vb2_plane_size(vb, 0) < sizeimage) {
                dev_dbg(veu->dev, "%s data will not fit into plane (%lu < %u)\n",
                        __func__, vb2_plane_size(vb, 0), sizeimage);
                return -EINVAL;
        }

        vb2_set_plane_payload(vb, 0, sizeimage);

        return 0;
}

static void sh_veu_buf_queue(struct vb2_buffer *vb)
{
        struct sh_veu_dev *veu = vb2_get_drv_priv(vb->vb2_queue);
        dev_dbg(veu->dev, "%s(%d)\n", __func__, vb->v4l2_buf.type);
        v4l2_m2m_buf_queue(veu->m2m_ctx, vb);
}

static const struct vb2_ops sh_veu_qops = {
        .queue_setup     = sh_veu_queue_setup,
        .buf_prepare     = sh_veu_buf_prepare,
        .buf_queue       = sh_veu_buf_queue,
        .wait_prepare    = vb2_ops_wait_prepare,
        .wait_finish     = vb2_ops_wait_finish,
};

static int sh_veu_queue_init(void *priv, struct vb2_queue *src_vq,
                             struct vb2_queue *dst_vq)
{
        struct sh_veu_dev *veu = priv;
        int ret;

        memset(src_vq, 0, sizeof(*src_vq));
        src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
        src_vq->io_modes = VB2_MMAP | VB2_USERPTR;
        src_vq->drv_priv = veu;
        src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
        src_vq->ops = &sh_veu_qops;
        src_vq->mem_ops = &vb2_dma_contig_memops;
        src_vq->lock = &veu->fop_lock;

        ret = vb2_queue_init(src_vq);
        if (ret < 0)
                return ret;

        memset(dst_vq, 0, sizeof(*dst_vq));
        dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        dst_vq->io_modes = VB2_MMAP | VB2_USERPTR;
        dst_vq->drv_priv = veu;
        dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
        dst_vq->ops = &sh_veu_qops;
        dst_vq->mem_ops = &vb2_dma_contig_memops;
        dst_vq->lock = &veu->fop_lock;

        return vb2_queue_init(dst_vq);
}

                /* ========== File operations ========== */

static int sh_veu_open(struct file *file)
{
        struct sh_veu_dev *veu = video_drvdata(file);
        struct sh_veu_file *veu_file;

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

        veu_file->veu_dev = veu;
        veu_file->cfg_needed = true;

        file->private_data = veu_file;

        pm_runtime_get_sync(veu->dev);

        dev_dbg(veu->dev, "Created instance %p\n", veu_file);

        return 0;
}

static int sh_veu_release(struct file *file)
{
        struct sh_veu_dev *veu = video_drvdata(file);
        struct sh_veu_file *veu_file = file->private_data;

        dev_dbg(veu->dev, "Releasing instance %p\n", veu_file);

        if (veu_file == veu->capture) {
                veu->capture = NULL;
                vb2_queue_release(v4l2_m2m_get_vq(veu->m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE));
        }

        if (veu_file == veu->output) {
                veu->output = NULL;
                vb2_queue_release(v4l2_m2m_get_vq(veu->m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT));
        }

        if (!veu->output && !veu->capture && veu->m2m_ctx) {
                v4l2_m2m_ctx_release(veu->m2m_ctx);
                veu->m2m_ctx = NULL;
        }

        pm_runtime_put(veu->dev);

        kfree(veu_file);

        return 0;
}

static unsigned int sh_veu_poll(struct file *file,
                                struct poll_table_struct *wait)
{
        struct sh_veu_file *veu_file = file->private_data;

        return v4l2_m2m_poll(file, veu_file->veu_dev->m2m_ctx, wait);
}

static int sh_veu_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct sh_veu_file *veu_file = file->private_data;

        return v4l2_m2m_mmap(file, veu_file->veu_dev->m2m_ctx, vma);
}

static const struct v4l2_file_operations sh_veu_fops = {
        .owner          = THIS_MODULE,
        .open           = sh_veu_open,
        .release        = sh_veu_release,
        .poll           = sh_veu_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = sh_veu_mmap,
};

static const struct video_device sh_veu_videodev = {
        .name           = "sh-veu",
        .fops           = &sh_veu_fops,
        .ioctl_ops      = &sh_veu_ioctl_ops,
        .minor          = -1,
        .release        = video_device_release_empty,
        .vfl_dir        = VFL_DIR_M2M,
};

static const struct v4l2_m2m_ops sh_veu_m2m_ops = {
        .device_run     = sh_veu_device_run,
        .job_abort      = sh_veu_job_abort,
};

static irqreturn_t sh_veu_bh(int irq, void *dev_id)
{
        struct sh_veu_dev *veu = dev_id;

        if (veu->xaction == MEM2MEM_DEF_TRANSLEN || veu->aborting) {
                v4l2_m2m_job_finish(veu->m2m_dev, veu->m2m_ctx);
                veu->xaction = 0;
        } else {
                sh_veu_device_run(veu);
        }

        return IRQ_HANDLED;
}

static irqreturn_t sh_veu_isr(int irq, void *dev_id)
{
        struct sh_veu_dev *veu = dev_id;
        struct vb2_buffer *dst;
        struct vb2_buffer *src;
        u32 status = sh_veu_reg_read(veu, VEU_EVTR);

        /* bundle read mode not used */
        if (!(status & 1))
                return IRQ_NONE;

        /* disable interrupt in VEU */
        sh_veu_reg_write(veu, VEU_EIER, 0);
        /* halt operation */
        sh_veu_reg_write(veu, VEU_STR, 0);
        /* ack int, write 0 to clear bits */
        sh_veu_reg_write(veu, VEU_EVTR, status & ~1);

        /* conversion completed */
        dst = v4l2_m2m_dst_buf_remove(veu->m2m_ctx);
        src = v4l2_m2m_src_buf_remove(veu->m2m_ctx);
        if (!src || !dst)
                return IRQ_NONE;

        spin_lock(&veu->lock);
        v4l2_m2m_buf_done(src, VB2_BUF_STATE_DONE);
        v4l2_m2m_buf_done(dst, VB2_BUF_STATE_DONE);
        spin_unlock(&veu->lock);

        veu->xaction++;

        return IRQ_WAKE_THREAD;
}

static int sh_veu_probe(struct platform_device *pdev)
{
        struct sh_veu_dev *veu;
        struct resource *reg_res;
        struct video_device *vdev;
        int irq, ret;

        reg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        irq = platform_get_irq(pdev, 0);

        if (!reg_res || irq <= 0) {
                dev_err(&pdev->dev, "Insufficient VEU platform information.\n");
                return -ENODEV;
        }

        veu = devm_kzalloc(&pdev->dev, sizeof(*veu), GFP_KERNEL);
        if (!veu)
                return -ENOMEM;

        veu->is_2h = resource_size(reg_res) == 0x22c;

        veu->base = devm_ioremap_resource(&pdev->dev, reg_res);
        if (IS_ERR(veu->base))
                return PTR_ERR(veu->base);

        ret = devm_request_threaded_irq(&pdev->dev, irq, sh_veu_isr, sh_veu_bh,
                                        0, "veu", veu);
        if (ret < 0)
                return ret;

        ret = v4l2_device_register(&pdev->dev, &veu->v4l2_dev);
        if (ret < 0) {
                dev_err(&pdev->dev, "Error registering v4l2 device\n");
                return ret;
        }

        vdev = &veu->vdev;

        veu->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
        if (IS_ERR(veu->alloc_ctx)) {
                ret = PTR_ERR(veu->alloc_ctx);
                goto einitctx;
        }

        *vdev = sh_veu_videodev;
        vdev->v4l2_dev = &veu->v4l2_dev;
        spin_lock_init(&veu->lock);
        mutex_init(&veu->fop_lock);
        vdev->lock = &veu->fop_lock;

        video_set_drvdata(vdev, veu);

        veu->dev        = &pdev->dev;
        veu->vfmt_out   = DEFAULT_OUT_VFMT;
        veu->vfmt_in    = DEFAULT_IN_VFMT;

        veu->m2m_dev = v4l2_m2m_init(&sh_veu_m2m_ops);
        if (IS_ERR(veu->m2m_dev)) {
                ret = PTR_ERR(veu->m2m_dev);
                v4l2_err(&veu->v4l2_dev, "Failed to init mem2mem device: %d\n", ret);
                goto em2minit;
        }

        pm_runtime_enable(&pdev->dev);
        pm_runtime_resume(&pdev->dev);

        ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
        pm_runtime_suspend(&pdev->dev);
        if (ret < 0)
                goto evidreg;

        return ret;

evidreg:
        pm_runtime_disable(&pdev->dev);
        v4l2_m2m_release(veu->m2m_dev);
em2minit:
        vb2_dma_contig_cleanup_ctx(veu->alloc_ctx);
einitctx:
        v4l2_device_unregister(&veu->v4l2_dev);
        return ret;
}

static int sh_veu_remove(struct platform_device *pdev)
{
        struct v4l2_device *v4l2_dev = platform_get_drvdata(pdev);
        struct sh_veu_dev *veu = container_of(v4l2_dev,
                                              struct sh_veu_dev, v4l2_dev);

        video_unregister_device(&veu->vdev);
        pm_runtime_disable(&pdev->dev);
        v4l2_m2m_release(veu->m2m_dev);
        vb2_dma_contig_cleanup_ctx(veu->alloc_ctx);
        v4l2_device_unregister(&veu->v4l2_dev);

        return 0;
}

static struct platform_driver __refdata sh_veu_pdrv = {
        .remove         = sh_veu_remove,
        .driver         = {
                .name   = "sh_veu",
        },
};

module_platform_driver_probe(sh_veu_pdrv, sh_veu_probe);

MODULE_DESCRIPTION("sh-mobile VEU mem2mem driver");
MODULE_AUTHOR("Guennadi Liakhovetski, <g.liakhovetski@gmx.de>");
MODULE_LICENSE("GPL v2");