mx2_emmaprp.c

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/*
 * Support eMMa-PrP through mem2mem framework.
 *
 * eMMa-PrP is a piece of HW that allows fetching buffers
 * from one memory location and do several operations on
 * them such as scaling or format conversion giving, as a result
 * a new processed buffer in another memory location.
 *
 * Based on mem2mem_testdev.c by Pawel Osciak.
 *
 * Copyright (c) 2011 Vista Silicon S.L.
 * Javier Martin <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version
 */
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/io.h>

#include <linux/platform_device.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-dma-contig.h>
#include <asm/sizes.h>

#define EMMAPRP_MODULE_NAME "mem2mem-emmaprp"

MODULE_DESCRIPTION("Mem-to-mem device which supports eMMa-PrP present in mx2 SoCs");
MODULE_AUTHOR("Javier Martin <[email protected]");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.0.1");

static bool debug;
module_param(debug, bool, 0644);

#define MIN_W 32
#define MIN_H 32
#define MAX_W 2040
#define MAX_H 2046

#define S_ALIGN     1 /* multiple of 2 */
#define W_ALIGN_YUV420  3 /* multiple of 8 */
#define W_ALIGN_OTHERS  2 /* multiple of 4 */
#define H_ALIGN     1 /* multiple of 2 */

/* Flags that indicate a format can be used for capture/output */
#define MEM2MEM_CAPTURE (1 << 0)
#define MEM2MEM_OUTPUT  (1 << 1)

#define MEM2MEM_NAME        "m2m-emmaprp"

/* In bytes, per queue */
#define MEM2MEM_VID_MEM_LIMIT   SZ_16M

#define dprintk(dev, fmt, arg...) \
    v4l2_dbg(1, debug, &dev->v4l2_dev, "%s: " fmt, __func__, ## arg)

/* EMMA PrP */
#define PRP_CNTL                        0x00
#define PRP_INTR_CNTL                   0x04
#define PRP_INTRSTATUS                  0x08
#define PRP_SOURCE_Y_PTR                0x0c
#define PRP_SOURCE_CB_PTR               0x10
#define PRP_SOURCE_CR_PTR               0x14
#define PRP_DEST_RGB1_PTR               0x18
#define PRP_DEST_RGB2_PTR               0x1c
#define PRP_DEST_Y_PTR                  0x20
#define PRP_DEST_CB_PTR                 0x24
#define PRP_DEST_CR_PTR                 0x28
#define PRP_SRC_FRAME_SIZE              0x2c
#define PRP_DEST_CH1_LINE_STRIDE        0x30
#define PRP_SRC_PIXEL_FORMAT_CNTL       0x34
#define PRP_CH1_PIXEL_FORMAT_CNTL       0x38
#define PRP_CH1_OUT_IMAGE_SIZE          0x3c
#define PRP_CH2_OUT_IMAGE_SIZE          0x40
#define PRP_SRC_LINE_STRIDE             0x44
#define PRP_CSC_COEF_012                0x48
#define PRP_CSC_COEF_345                0x4c
#define PRP_CSC_COEF_678                0x50
#define PRP_CH1_RZ_HORI_COEF1           0x54
#define PRP_CH1_RZ_HORI_COEF2           0x58
#define PRP_CH1_RZ_HORI_VALID           0x5c
#define PRP_CH1_RZ_VERT_COEF1           0x60
#define PRP_CH1_RZ_VERT_COEF2           0x64
#define PRP_CH1_RZ_VERT_VALID           0x68
#define PRP_CH2_RZ_HORI_COEF1           0x6c
#define PRP_CH2_RZ_HORI_COEF2           0x70
#define PRP_CH2_RZ_HORI_VALID           0x74
#define PRP_CH2_RZ_VERT_COEF1           0x78
#define PRP_CH2_RZ_VERT_COEF2           0x7c
#define PRP_CH2_RZ_VERT_VALID           0x80

#define PRP_CNTL_CH1EN          (1 << 0)
#define PRP_CNTL_CH2EN          (1 << 1)
#define PRP_CNTL_CSIEN          (1 << 2)
#define PRP_CNTL_DATA_IN_YUV420 (0 << 3)
#define PRP_CNTL_DATA_IN_YUV422 (1 << 3)
#define PRP_CNTL_DATA_IN_RGB16  (2 << 3)
#define PRP_CNTL_DATA_IN_RGB32  (3 << 3)
#define PRP_CNTL_CH1_OUT_RGB8   (0 << 5)
#define PRP_CNTL_CH1_OUT_RGB16  (1 << 5)
#define PRP_CNTL_CH1_OUT_RGB32  (2 << 5)
#define PRP_CNTL_CH1_OUT_YUV422 (3 << 5)
#define PRP_CNTL_CH2_OUT_YUV420 (0 << 7)
#define PRP_CNTL_CH2_OUT_YUV422 (1 << 7)
#define PRP_CNTL_CH2_OUT_YUV444 (2 << 7)
#define PRP_CNTL_CH1_LEN        (1 << 9)
#define PRP_CNTL_CH2_LEN        (1 << 10)
#define PRP_CNTL_SKIP_FRAME     (1 << 11)
#define PRP_CNTL_SWRST          (1 << 12)
#define PRP_CNTL_CLKEN          (1 << 13)
#define PRP_CNTL_WEN            (1 << 14)
#define PRP_CNTL_CH1BYP         (1 << 15)
#define PRP_CNTL_IN_TSKIP(x)    ((x) << 16)
#define PRP_CNTL_CH1_TSKIP(x)   ((x) << 19)
#define PRP_CNTL_CH2_TSKIP(x)   ((x) << 22)
#define PRP_CNTL_INPUT_FIFO_LEVEL(x)    ((x) << 25)
#define PRP_CNTL_RZ_FIFO_LEVEL(x)       ((x) << 27)
#define PRP_CNTL_CH2B1EN        (1 << 29)
#define PRP_CNTL_CH2B2EN        (1 << 30)
#define PRP_CNTL_CH2FEN         (1 << 31)

#define PRP_SIZE_HEIGHT(x)  (x)
#define PRP_SIZE_WIDTH(x)   ((x) << 16)

/* IRQ Enable and status register */
#define PRP_INTR_RDERR          (1 << 0)
#define PRP_INTR_CH1WERR        (1 << 1)
#define PRP_INTR_CH2WERR        (1 << 2)
#define PRP_INTR_CH1FC          (1 << 3)
#define PRP_INTR_CH2FC          (1 << 5)
#define PRP_INTR_LBOVF          (1 << 7)
#define PRP_INTR_CH2OVF         (1 << 8)

#define PRP_INTR_ST_RDERR   (1 << 0)
#define PRP_INTR_ST_CH1WERR (1 << 1)
#define PRP_INTR_ST_CH2WERR (1 << 2)
#define PRP_INTR_ST_CH2B2CI (1 << 3)
#define PRP_INTR_ST_CH2B1CI (1 << 4)
#define PRP_INTR_ST_CH1B2CI (1 << 5)
#define PRP_INTR_ST_CH1B1CI (1 << 6)
#define PRP_INTR_ST_LBOVF   (1 << 7)
#define PRP_INTR_ST_CH2OVF  (1 << 8)

struct emmaprp_fmt {
    char    *name;
    u32 fourcc;
    /* Types the format can be used for */
    u32 types;
};

static struct emmaprp_fmt formats[] = {
    {
        .name   = "YUV 4:2:0 Planar",
        .fourcc = V4L2_PIX_FMT_YUV420,
        .types  = MEM2MEM_CAPTURE,
    },
    {
        .name   = "4:2:2, packed, YUYV",
        .fourcc = V4L2_PIX_FMT_YUYV,
        .types  = MEM2MEM_OUTPUT,
    },
};

/* Per-queue, driver-specific private data */
struct emmaprp_q_data {
    unsigned int        width;
    unsigned int        height;
    unsigned int        sizeimage;
    struct emmaprp_fmt  *fmt;
};

enum {
    V4L2_M2M_SRC = 0,
    V4L2_M2M_DST = 1,
};

#define NUM_FORMATS ARRAY_SIZE(formats)

static struct emmaprp_fmt *find_format(struct v4l2_format *f)
{
    struct emmaprp_fmt *fmt;
    unsigned int k;

    for (k = 0; k < NUM_FORMATS; k++) {
        fmt = &formats[k];
        if (fmt->fourcc == f->fmt.pix.pixelformat)
            break;
    }

    if (k == NUM_FORMATS)
        return NULL;

    return &formats[k];
}

struct emmaprp_dev {
    struct v4l2_device  v4l2_dev;
    struct video_device *vfd;

    struct mutex        dev_mutex;
    spinlock_t      irqlock;

    int         irq_emma;
    void __iomem        *base_emma;
    struct clk      *clk_emma_ahb, *clk_emma_ipg;
    struct resource     *res_emma;

    struct v4l2_m2m_dev *m2m_dev;
    struct vb2_alloc_ctx    *alloc_ctx;
};

struct emmaprp_ctx {
    struct emmaprp_dev  *dev;
    /* Abort requested by m2m */
    int         aborting;
    struct emmaprp_q_data   q_data[2];
    struct v4l2_m2m_ctx *m2m_ctx;
};

static struct emmaprp_q_data *get_q_data(struct emmaprp_ctx *ctx,
                     enum v4l2_buf_type type)
{
    switch (type) {
    case V4L2_BUF_TYPE_VIDEO_OUTPUT:
        return &(ctx->q_data[V4L2_M2M_SRC]);
    case V4L2_BUF_TYPE_VIDEO_CAPTURE:
        return &(ctx->q_data[V4L2_M2M_DST]);
    default:
        BUG();
    }
    return NULL;
}

/*
 * mem2mem callbacks
 */
static void emmaprp_job_abort(void *priv)
{
    struct emmaprp_ctx *ctx = priv;
    struct emmaprp_dev *pcdev = ctx->dev;

    ctx->aborting = 1;

    dprintk(pcdev, "Aborting task\n");

    v4l2_m2m_job_finish(pcdev->m2m_dev, ctx->m2m_ctx);
}

static void emmaprp_lock(void *priv)
{
    struct emmaprp_ctx *ctx = priv;
    struct emmaprp_dev *pcdev = ctx->dev;
    mutex_lock(&pcdev->dev_mutex);
}

static void emmaprp_unlock(void *priv)
{
    struct emmaprp_ctx *ctx = priv;
    struct emmaprp_dev *pcdev = ctx->dev;
    mutex_unlock(&pcdev->dev_mutex);
}

static inline void emmaprp_dump_regs(struct emmaprp_dev *pcdev)
{
    dprintk(pcdev,
        "eMMa-PrP Registers:\n"
        "  SOURCE_Y_PTR = 0x%08X\n"
        "  SRC_FRAME_SIZE = 0x%08X\n"
        "  DEST_Y_PTR = 0x%08X\n"
        "  DEST_CR_PTR = 0x%08X\n"
        "  DEST_CB_PTR = 0x%08X\n"
        "  CH2_OUT_IMAGE_SIZE = 0x%08X\n"
        "  CNTL = 0x%08X\n",
        readl(pcdev->base_emma + PRP_SOURCE_Y_PTR),
        readl(pcdev->base_emma + PRP_SRC_FRAME_SIZE),
        readl(pcdev->base_emma + PRP_DEST_Y_PTR),
        readl(pcdev->base_emma + PRP_DEST_CR_PTR),
        readl(pcdev->base_emma + PRP_DEST_CB_PTR),
        readl(pcdev->base_emma + PRP_CH2_OUT_IMAGE_SIZE),
        readl(pcdev->base_emma + PRP_CNTL));
}

static void emmaprp_device_run(void *priv)
{
    struct emmaprp_ctx *ctx = priv;
    struct emmaprp_q_data *s_q_data, *d_q_data;
    struct vb2_buffer *src_buf, *dst_buf;
    struct emmaprp_dev *pcdev = ctx->dev;
    unsigned int s_width, s_height;
    unsigned int d_width, d_height;
    unsigned int d_size;
    dma_addr_t p_in, p_out;
    u32 tmp;

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

    s_q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
    s_width = s_q_data->width;
    s_height = s_q_data->height;

    d_q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
    d_width = d_q_data->width;
    d_height = d_q_data->height;
    d_size = d_width * d_height;

    p_in = vb2_dma_contig_plane_dma_addr(src_buf, 0);
    p_out = vb2_dma_contig_plane_dma_addr(dst_buf, 0);
    if (!p_in || !p_out) {
        v4l2_err(&pcdev->v4l2_dev,
             "Acquiring kernel pointers to buffers failed\n");
        return;
    }

    /* Input frame parameters */
    writel(p_in, pcdev->base_emma + PRP_SOURCE_Y_PTR);
    writel(PRP_SIZE_WIDTH(s_width) | PRP_SIZE_HEIGHT(s_height),
           pcdev->base_emma + PRP_SRC_FRAME_SIZE);

    /* Output frame parameters */
    writel(p_out, pcdev->base_emma + PRP_DEST_Y_PTR);
    writel(p_out + d_size, pcdev->base_emma + PRP_DEST_CB_PTR);
    writel(p_out + d_size + (d_size >> 2),
           pcdev->base_emma + PRP_DEST_CR_PTR);
    writel(PRP_SIZE_WIDTH(d_width) | PRP_SIZE_HEIGHT(d_height),
           pcdev->base_emma + PRP_CH2_OUT_IMAGE_SIZE);

    /* IRQ configuration */
    tmp = readl(pcdev->base_emma + PRP_INTR_CNTL);
    writel(tmp | PRP_INTR_RDERR |
        PRP_INTR_CH2WERR |
        PRP_INTR_CH2FC,
        pcdev->base_emma + PRP_INTR_CNTL);

    emmaprp_dump_regs(pcdev);

    /* Enable transfer */
    tmp = readl(pcdev->base_emma + PRP_CNTL);
    writel(tmp | PRP_CNTL_CH2_OUT_YUV420 |
        PRP_CNTL_DATA_IN_YUV422 |
        PRP_CNTL_CH2EN,
        pcdev->base_emma + PRP_CNTL);
}

static irqreturn_t emmaprp_irq(int irq_emma, void *data)
{
    struct emmaprp_dev *pcdev = data;
    struct emmaprp_ctx *curr_ctx;
    struct vb2_buffer *src_vb, *dst_vb;
    unsigned long flags;
    u32 irqst;

    /* Check irq flags and clear irq */
    irqst = readl(pcdev->base_emma + PRP_INTRSTATUS);
    writel(irqst, pcdev->base_emma + PRP_INTRSTATUS);
    dprintk(pcdev, "irqst = 0x%08x\n", irqst);

    curr_ctx = v4l2_m2m_get_curr_priv(pcdev->m2m_dev);
    if (curr_ctx == NULL) {
        pr_err("Instance released before the end of transaction\n");
        return IRQ_HANDLED;
    }

    if (!curr_ctx->aborting) {
        if ((irqst & PRP_INTR_ST_RDERR) ||
        (irqst & PRP_INTR_ST_CH2WERR)) {
            pr_err("PrP bus error ocurred, this transfer is probably corrupted\n");
            writel(PRP_CNTL_SWRST, pcdev->base_emma + PRP_CNTL);
        } else if (irqst & PRP_INTR_ST_CH2B1CI) { /* buffer ready */
            src_vb = v4l2_m2m_src_buf_remove(curr_ctx->m2m_ctx);
            dst_vb = v4l2_m2m_dst_buf_remove(curr_ctx->m2m_ctx);

            spin_lock_irqsave(&pcdev->irqlock, flags);
            v4l2_m2m_buf_done(src_vb, VB2_BUF_STATE_DONE);
            v4l2_m2m_buf_done(dst_vb, VB2_BUF_STATE_DONE);
            spin_unlock_irqrestore(&pcdev->irqlock, flags);
        }
    }

    v4l2_m2m_job_finish(pcdev->m2m_dev, curr_ctx->m2m_ctx);
    return IRQ_HANDLED;
}

/*
 * video ioctls
 */
static int vidioc_querycap(struct file *file, void *priv,
               struct v4l2_capability *cap)
{
    strncpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver) - 1);
    strncpy(cap->card, MEM2MEM_NAME, sizeof(cap->card) - 1);
    /*
     * This is only a mem-to-mem video device. The capture and output
     * device capability flags are left only for backward compatibility
     * and are scheduled for removal.
     */
    cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT |
                V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
    return 0;
}

static int enum_fmt(struct v4l2_fmtdesc *f, u32 type)
{
    int i, num;
    struct emmaprp_fmt *fmt;

    num = 0;

    for (i = 0; i < NUM_FORMATS; ++i) {
        if (formats[i].types & type) {
            /* index-th format of type type found ? */
            if (num == f->index)
                break;
            /* Correct type but haven't reached our index yet,
             * just increment per-type index */
            ++num;
        }
    }

    if (i < NUM_FORMATS) {
        /* Format found */
        fmt = &formats[i];
        strlcpy(f->description, fmt->name, sizeof(f->description) - 1);
        f->pixelformat = fmt->fourcc;
        return 0;
    }

    /* Format not found */
    return -EINVAL;
}

static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
                   struct v4l2_fmtdesc *f)
{
    return enum_fmt(f, MEM2MEM_CAPTURE);
}

static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
                   struct v4l2_fmtdesc *f)
{
    return enum_fmt(f, MEM2MEM_OUTPUT);
}

static int vidioc_g_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
{
    struct vb2_queue *vq;
    struct emmaprp_q_data *q_data;

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

    q_data = get_q_data(ctx, f->type);

    f->fmt.pix.width    = q_data->width;
    f->fmt.pix.height   = q_data->height;
    f->fmt.pix.field    = V4L2_FIELD_NONE;
    f->fmt.pix.pixelformat  = q_data->fmt->fourcc;
    if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_YUV420)
        f->fmt.pix.bytesperline = q_data->width * 3 / 2;
    else /* YUYV */
        f->fmt.pix.bytesperline = q_data->width * 2;
    f->fmt.pix.sizeimage    = q_data->sizeimage;

    return 0;
}

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

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

static int vidioc_try_fmt(struct v4l2_format *f)
{
    enum v4l2_field field;


    if (!find_format(f))
        return -EINVAL;

    field = f->fmt.pix.field;
    if (field == V4L2_FIELD_ANY)
        field = V4L2_FIELD_NONE;
    else if (V4L2_FIELD_NONE != field)
        return -EINVAL;

    /* V4L2 specification suggests the driver corrects the format struct
     * if any of the dimensions is unsupported */
    f->fmt.pix.field = field;

    if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_YUV420) {
        v4l_bound_align_image(&f->fmt.pix.width, MIN_W, MAX_W,
                      W_ALIGN_YUV420, &f->fmt.pix.height,
                      MIN_H, MAX_H, H_ALIGN, S_ALIGN);
        f->fmt.pix.bytesperline = f->fmt.pix.width * 3 / 2;
    } else {
        v4l_bound_align_image(&f->fmt.pix.width, MIN_W, MAX_W,
                      W_ALIGN_OTHERS, &f->fmt.pix.height,
                      MIN_H, MAX_H, H_ALIGN, S_ALIGN);
        f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
    }
    f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;

    return 0;
}

static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
                  struct v4l2_format *f)
{
    struct emmaprp_fmt *fmt;
    struct emmaprp_ctx *ctx = priv;

    fmt = find_format(f);
    if (!fmt || !(fmt->types & MEM2MEM_CAPTURE)) {
        v4l2_err(&ctx->dev->v4l2_dev,
             "Fourcc format (0x%08x) invalid.\n",
             f->fmt.pix.pixelformat);
        return -EINVAL;
    }

    return vidioc_try_fmt(f);
}

static int vidioc_try_fmt_vid_out(struct file *file, void *priv,
                  struct v4l2_format *f)
{
    struct emmaprp_fmt *fmt;
    struct emmaprp_ctx *ctx = priv;

    fmt = find_format(f);
    if (!fmt || !(fmt->types & MEM2MEM_OUTPUT)) {
        v4l2_err(&ctx->dev->v4l2_dev,
             "Fourcc format (0x%08x) invalid.\n",
             f->fmt.pix.pixelformat);
        return -EINVAL;
    }

    return vidioc_try_fmt(f);
}

static int vidioc_s_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
{
    struct emmaprp_q_data *q_data;
    struct vb2_queue *vq;
    int ret;

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

    q_data = get_q_data(ctx, f->type);
    if (!q_data)
        return -EINVAL;

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

    ret = vidioc_try_fmt(f);
    if (ret)
        return ret;

    q_data->fmt     = find_format(f);
    q_data->width       = f->fmt.pix.width;
    q_data->height      = f->fmt.pix.height;
    if (q_data->fmt->fourcc == V4L2_PIX_FMT_YUV420)
        q_data->sizeimage = q_data->width * q_data->height * 3 / 2;
    else /* YUYV */
        q_data->sizeimage = q_data->width * q_data->height * 2;

    dprintk(ctx->dev,
        "Setting format for type %d, wxh: %dx%d, fmt: %d\n",
        f->type, q_data->width, q_data->height, q_data->fmt->fourcc);

    return 0;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
    int ret;

    ret = vidioc_try_fmt_vid_cap(file, priv, f);
    if (ret)
        return ret;

    return vidioc_s_fmt(priv, f);
}

static int vidioc_s_fmt_vid_out(struct file *file, void *priv,
                struct v4l2_format *f)
{
    int ret;

    ret = vidioc_try_fmt_vid_out(file, priv, f);
    if (ret)
        return ret;

    return vidioc_s_fmt(priv, f);
}

static int vidioc_reqbufs(struct file *file, void *priv,
              struct v4l2_requestbuffers *reqbufs)
{
    struct emmaprp_ctx *ctx = priv;

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

static int vidioc_querybuf(struct file *file, void *priv,
               struct v4l2_buffer *buf)
{
    struct emmaprp_ctx *ctx = priv;

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

static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
    struct emmaprp_ctx *ctx = priv;

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

static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
    struct emmaprp_ctx *ctx = priv;

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

static int vidioc_streamon(struct file *file, void *priv,
               enum v4l2_buf_type type)
{
    struct emmaprp_ctx *ctx = priv;

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

static int vidioc_streamoff(struct file *file, void *priv,
                enum v4l2_buf_type type)
{
    struct emmaprp_ctx *ctx = priv;

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

static const struct v4l2_ioctl_ops emmaprp_ioctl_ops = {
    .vidioc_querycap    = vidioc_querycap,

    .vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
    .vidioc_g_fmt_vid_cap   = vidioc_g_fmt_vid_cap,
    .vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,
    .vidioc_s_fmt_vid_cap   = vidioc_s_fmt_vid_cap,

    .vidioc_enum_fmt_vid_out = vidioc_enum_fmt_vid_out,
    .vidioc_g_fmt_vid_out   = vidioc_g_fmt_vid_out,
    .vidioc_try_fmt_vid_out = vidioc_try_fmt_vid_out,
    .vidioc_s_fmt_vid_out   = vidioc_s_fmt_vid_out,

    .vidioc_reqbufs     = vidioc_reqbufs,
    .vidioc_querybuf    = vidioc_querybuf,

    .vidioc_qbuf        = vidioc_qbuf,
    .vidioc_dqbuf       = vidioc_dqbuf,

    .vidioc_streamon    = vidioc_streamon,
    .vidioc_streamoff   = vidioc_streamoff,
};


/*
 * Queue operations
 */
static int emmaprp_queue_setup(struct vb2_queue *vq,
                const struct v4l2_format *fmt,
                unsigned int *nbuffers, unsigned int *nplanes,
                unsigned int sizes[], void *alloc_ctxs[])
{
    struct emmaprp_ctx *ctx = vb2_get_drv_priv(vq);
    struct emmaprp_q_data *q_data;
    unsigned int size, count = *nbuffers;

    q_data = get_q_data(ctx, vq->type);

    if (q_data->fmt->fourcc == V4L2_PIX_FMT_YUV420)
        size = q_data->width * q_data->height * 3 / 2;
    else
        size = q_data->width * q_data->height * 2;

    while (size * count > MEM2MEM_VID_MEM_LIMIT)
        (count)--;

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

    alloc_ctxs[0] = ctx->dev->alloc_ctx;

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

    return 0;
}

static int emmaprp_buf_prepare(struct vb2_buffer *vb)
{
    struct emmaprp_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
    struct emmaprp_q_data *q_data;

    dprintk(ctx->dev, "type: %d\n", vb->vb2_queue->type);

    q_data = get_q_data(ctx, vb->vb2_queue->type);

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

    vb2_set_plane_payload(vb, 0, q_data->sizeimage);

    return 0;
}

static void emmaprp_buf_queue(struct vb2_buffer *vb)
{
    struct emmaprp_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
    v4l2_m2m_buf_queue(ctx->m2m_ctx, vb);
}

static struct vb2_ops emmaprp_qops = {
    .queue_setup     = emmaprp_queue_setup,
    .buf_prepare     = emmaprp_buf_prepare,
    .buf_queue   = emmaprp_buf_queue,
};

static int queue_init(void *priv, struct vb2_queue *src_vq,
              struct vb2_queue *dst_vq)
{
    struct emmaprp_ctx *ctx = priv;
    int ret;

    src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
    src_vq->io_modes = VB2_MMAP | VB2_USERPTR;
    src_vq->drv_priv = ctx;
    src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
    src_vq->ops = &emmaprp_qops;
    src_vq->mem_ops = &vb2_dma_contig_memops;

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

    dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    dst_vq->io_modes = VB2_MMAP | VB2_USERPTR;
    dst_vq->drv_priv = ctx;
    dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
    dst_vq->ops = &emmaprp_qops;
    dst_vq->mem_ops = &vb2_dma_contig_memops;

    return vb2_queue_init(dst_vq);
}

/*
 * File operations
 */
static int emmaprp_open(struct file *file)
{
    struct emmaprp_dev *pcdev = video_drvdata(file);
    struct emmaprp_ctx *ctx;

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

    file->private_data = ctx;
    ctx->dev = pcdev;

    if (mutex_lock_interruptible(&pcdev->dev_mutex)) {
        kfree(ctx);
        return -ERESTARTSYS;
    }

    ctx->m2m_ctx = v4l2_m2m_ctx_init(pcdev->m2m_dev, ctx, &queue_init);

    if (IS_ERR(ctx->m2m_ctx)) {
        int ret = PTR_ERR(ctx->m2m_ctx);

        mutex_unlock(&pcdev->dev_mutex);
        kfree(ctx);
        return ret;
    }

    clk_prepare_enable(pcdev->clk_emma_ipg);
    clk_prepare_enable(pcdev->clk_emma_ahb);
    ctx->q_data[V4L2_M2M_SRC].fmt = &formats[1];
    ctx->q_data[V4L2_M2M_DST].fmt = &formats[0];
    mutex_unlock(&pcdev->dev_mutex);

    dprintk(pcdev, "Created instance %p, m2m_ctx: %p\n", ctx, ctx->m2m_ctx);

    return 0;
}

static int emmaprp_release(struct file *file)
{
    struct emmaprp_dev *pcdev = video_drvdata(file);
    struct emmaprp_ctx *ctx = file->private_data;

    dprintk(pcdev, "Releasing instance %p\n", ctx);

    mutex_lock(&pcdev->dev_mutex);
    clk_disable_unprepare(pcdev->clk_emma_ahb);
    clk_disable_unprepare(pcdev->clk_emma_ipg);
    v4l2_m2m_ctx_release(ctx->m2m_ctx);
    mutex_unlock(&pcdev->dev_mutex);
    kfree(ctx);

    return 0;
}

static unsigned int emmaprp_poll(struct file *file,
                 struct poll_table_struct *wait)
{
    struct emmaprp_dev *pcdev = video_drvdata(file);
    struct emmaprp_ctx *ctx = file->private_data;
    unsigned int res;

    mutex_lock(&pcdev->dev_mutex);
    res = v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
    mutex_unlock(&pcdev->dev_mutex);
    return res;
}

static int emmaprp_mmap(struct file *file, struct vm_area_struct *vma)
{
    struct emmaprp_dev *pcdev = video_drvdata(file);
    struct emmaprp_ctx *ctx = file->private_data;
    int ret;

    if (mutex_lock_interruptible(&pcdev->dev_mutex))
        return -ERESTARTSYS;
    ret = v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
    mutex_unlock(&pcdev->dev_mutex);
    return ret;
}

static const struct v4l2_file_operations emmaprp_fops = {
    .owner      = THIS_MODULE,
    .open       = emmaprp_open,
    .release    = emmaprp_release,
    .poll       = emmaprp_poll,
    .unlocked_ioctl = video_ioctl2,
    .mmap       = emmaprp_mmap,
};

static struct video_device emmaprp_videodev = {
    .name       = MEM2MEM_NAME,
    .fops       = &emmaprp_fops,
    .ioctl_ops  = &emmaprp_ioctl_ops,
    .minor      = -1,
    .release    = video_device_release,
    .vfl_dir    = VFL_DIR_M2M,
};

static struct v4l2_m2m_ops m2m_ops = {
    .device_run = emmaprp_device_run,
    .job_abort  = emmaprp_job_abort,
    .lock       = emmaprp_lock,
    .unlock     = emmaprp_unlock,
};

static int emmaprp_probe(struct platform_device *pdev)
{
    struct emmaprp_dev *pcdev;
    struct video_device *vfd;
    struct resource *res_emma;
    int irq_emma;
    int ret;

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

    spin_lock_init(&pcdev->irqlock);

    pcdev->clk_emma_ipg = devm_clk_get(&pdev->dev, "ipg");
    if (IS_ERR(pcdev->clk_emma_ipg)) {
        return PTR_ERR(pcdev->clk_emma_ipg);
    }

    pcdev->clk_emma_ahb = devm_clk_get(&pdev->dev, "ahb");
    if (IS_ERR(pcdev->clk_emma_ahb))
        return PTR_ERR(pcdev->clk_emma_ahb);

    irq_emma = platform_get_irq(pdev, 0);
    res_emma = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (irq_emma < 0 || res_emma == NULL) {
        dev_err(&pdev->dev, "Missing platform resources data\n");
        return -ENODEV;
    }

    ret = v4l2_device_register(&pdev->dev, &pcdev->v4l2_dev);
    if (ret)
        return ret;

    mutex_init(&pcdev->dev_mutex);

    vfd = video_device_alloc();
    if (!vfd) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to allocate video device\n");
        ret = -ENOMEM;
        goto unreg_dev;
    }

    *vfd = emmaprp_videodev;
    vfd->lock = &pcdev->dev_mutex;

    video_set_drvdata(vfd, pcdev);
    snprintf(vfd->name, sizeof(vfd->name), "%s", emmaprp_videodev.name);
    pcdev->vfd = vfd;
    v4l2_info(&pcdev->v4l2_dev, EMMAPRP_MODULE_NAME
            " Device registered as /dev/video%d\n", vfd->num);

    platform_set_drvdata(pdev, pcdev);

    pcdev->base_emma = devm_request_and_ioremap(&pdev->dev, res_emma);
    if (!pcdev->base_emma) {
        ret = -ENXIO;
        goto rel_vdev;
    }

    pcdev->irq_emma = irq_emma;
    pcdev->res_emma = res_emma;

    if (devm_request_irq(&pdev->dev, pcdev->irq_emma, emmaprp_irq,
                 0, MEM2MEM_NAME, pcdev) < 0) {
        ret = -ENODEV;
        goto rel_vdev;
    }

    pcdev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
    if (IS_ERR(pcdev->alloc_ctx)) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to alloc vb2 context\n");
        ret = PTR_ERR(pcdev->alloc_ctx);
        goto rel_vdev;
    }

    pcdev->m2m_dev = v4l2_m2m_init(&m2m_ops);
    if (IS_ERR(pcdev->m2m_dev)) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to init mem2mem device\n");
        ret = PTR_ERR(pcdev->m2m_dev);
        goto rel_ctx;
    }

    ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
    if (ret) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to register video device\n");
        goto rel_m2m;
    }

    return 0;


rel_m2m:
    v4l2_m2m_release(pcdev->m2m_dev);
rel_ctx:
    vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
rel_vdev:
    video_device_release(vfd);
unreg_dev:
    v4l2_device_unregister(&pcdev->v4l2_dev);

    return ret;
}

static int emmaprp_remove(struct platform_device *pdev)
{
    struct emmaprp_dev *pcdev = platform_get_drvdata(pdev);

    v4l2_info(&pcdev->v4l2_dev, "Removing " EMMAPRP_MODULE_NAME);

    video_unregister_device(pcdev->vfd);
    v4l2_m2m_release(pcdev->m2m_dev);
    vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
    v4l2_device_unregister(&pcdev->v4l2_dev);

    return 0;
}

static struct platform_driver emmaprp_pdrv = {
    .probe      = emmaprp_probe,
    .remove     = emmaprp_remove,
    .driver     = {
        .name   = MEM2MEM_NAME,
        .owner  = THIS_MODULE,
    },
};

static void __exit emmaprp_exit(void)
{
    platform_driver_unregister(&emmaprp_pdrv);
}

static int __init emmaprp_init(void)
{
    return platform_driver_register(&emmaprp_pdrv);
}

module_init(emmaprp_init);
module_exit(emmaprp_exit);