// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * vimc-scaler.c Virtual Media Controller Driver
 *
 * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
 */

#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/v4l2-mediabus.h>
#include <media/v4l2-rect.h>
#include <media/v4l2-subdev.h>

#include "vimc-common.h"

static unsigned int sca_mult = 3;
module_param(sca_mult, uint, 0000);
MODULE_PARM_DESC(sca_mult, " the image size multiplier");

#define MAX_ZOOM        8

#define VIMC_SCA_FMT_WIDTH_DEFAULT  640
#define VIMC_SCA_FMT_HEIGHT_DEFAULT 480

struct vimc_sca_device {
        struct vimc_ent_device ved;
        struct v4l2_subdev sd;
        /* NOTE: the source fmt is the same as the sink
         * with the width and hight multiplied by mult
         */
        struct v4l2_mbus_framefmt sink_fmt;
        struct v4l2_rect crop_rect;
        /* Values calculated when the stream starts */
        u8 *src_frame;
        unsigned int src_line_size;
        unsigned int bpp;
        struct media_pad pads[2];
};

static const struct v4l2_mbus_framefmt sink_fmt_default = {
        .width = VIMC_SCA_FMT_WIDTH_DEFAULT,
        .height = VIMC_SCA_FMT_HEIGHT_DEFAULT,
        .code = MEDIA_BUS_FMT_RGB888_1X24,
        .field = V4L2_FIELD_NONE,
        .colorspace = V4L2_COLORSPACE_SRGB,
};

static const struct v4l2_rect crop_rect_default = {
        .width = VIMC_SCA_FMT_WIDTH_DEFAULT,
        .height = VIMC_SCA_FMT_HEIGHT_DEFAULT,
        .top = 0,
        .left = 0,
};

static const struct v4l2_rect crop_rect_min = {
        .width = VIMC_FRAME_MIN_WIDTH,
        .height = VIMC_FRAME_MIN_HEIGHT,
        .top = 0,
        .left = 0,
};

static struct v4l2_rect
vimc_sca_get_crop_bound_sink(const struct v4l2_mbus_framefmt *sink_fmt)
{
        /* Get the crop bounds to clamp the crop rectangle correctly */
        struct v4l2_rect r = {
                .left = 0,
                .top = 0,
                .width = sink_fmt->width,
                .height = sink_fmt->height,
        };
        return r;
}

static void vimc_sca_adjust_sink_crop(struct v4l2_rect *r,
                                      const struct v4l2_mbus_framefmt *sink_fmt)
{
        const struct v4l2_rect sink_rect =
                vimc_sca_get_crop_bound_sink(sink_fmt);

        /* Disallow rectangles smaller than the minimal one. */
        v4l2_rect_set_min_size(r, &crop_rect_min);
        v4l2_rect_map_inside(r, &sink_rect);
}

static int vimc_sca_init_cfg(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *sd_state)
{
        struct v4l2_mbus_framefmt *mf;
        struct v4l2_rect *r;
        unsigned int i;

        mf = v4l2_subdev_get_try_format(sd, sd_state, 0);
        *mf = sink_fmt_default;

        r = v4l2_subdev_get_try_crop(sd, sd_state, 0);
        *r = crop_rect_default;

        for (i = 1; i < sd->entity.num_pads; i++) {
                mf = v4l2_subdev_get_try_format(sd, sd_state, i);
                *mf = sink_fmt_default;
                mf->width = mf->width * sca_mult;
                mf->height = mf->height * sca_mult;
        }

        return 0;
}

static int vimc_sca_enum_mbus_code(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_state *sd_state,
                                   struct v4l2_subdev_mbus_code_enum *code)
{
        u32 mbus_code = vimc_mbus_code_by_index(code->index);
        const struct vimc_pix_map *vpix;

        if (!mbus_code)
                return -EINVAL;

        vpix = vimc_pix_map_by_code(mbus_code);

        /* We don't support bayer format */
        if (!vpix || vpix->bayer)
                return -EINVAL;

        code->code = mbus_code;

        return 0;
}

static int vimc_sca_enum_frame_size(struct v4l2_subdev *sd,
                                    struct v4l2_subdev_state *sd_state,
                                    struct v4l2_subdev_frame_size_enum *fse)
{
        const struct vimc_pix_map *vpix;

        if (fse->index)
                return -EINVAL;

        /* Only accept code in the pix map table in non bayer format */
        vpix = vimc_pix_map_by_code(fse->code);
        if (!vpix || vpix->bayer)
                return -EINVAL;

        fse->min_width = VIMC_FRAME_MIN_WIDTH;
        fse->min_height = VIMC_FRAME_MIN_HEIGHT;

        if (VIMC_IS_SINK(fse->pad)) {
                fse->max_width = VIMC_FRAME_MAX_WIDTH;
                fse->max_height = VIMC_FRAME_MAX_HEIGHT;
        } else {
                fse->max_width = VIMC_FRAME_MAX_WIDTH * MAX_ZOOM;
                fse->max_height = VIMC_FRAME_MAX_HEIGHT * MAX_ZOOM;
        }

        return 0;
}

static int vimc_sca_get_fmt(struct v4l2_subdev *sd,
                            struct v4l2_subdev_state *sd_state,
                            struct v4l2_subdev_format *format)
{
        struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
        struct v4l2_rect *crop_rect;

        /* Get the current sink format */
        if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
                format->format = *v4l2_subdev_get_try_format(sd, sd_state, 0);
                crop_rect = v4l2_subdev_get_try_crop(sd, sd_state, 0);
        } else {
                format->format = vsca->sink_fmt;
                crop_rect = &vsca->crop_rect;
        }

        /* Scale the frame size for the source pad */
        if (VIMC_IS_SRC(format->pad)) {
                format->format.width = crop_rect->width * sca_mult;
                format->format.height = crop_rect->height * sca_mult;
        }

        return 0;
}

static void vimc_sca_adjust_sink_fmt(struct v4l2_mbus_framefmt *fmt)
{
        const struct vimc_pix_map *vpix;

        /* Only accept code in the pix map table in non bayer format */
        vpix = vimc_pix_map_by_code(fmt->code);
        if (!vpix || vpix->bayer)
                fmt->code = sink_fmt_default.code;

        fmt->width = clamp_t(u32, fmt->width, VIMC_FRAME_MIN_WIDTH,
                             VIMC_FRAME_MAX_WIDTH) & ~1;
        fmt->height = clamp_t(u32, fmt->height, VIMC_FRAME_MIN_HEIGHT,
                              VIMC_FRAME_MAX_HEIGHT) & ~1;

        if (fmt->field == V4L2_FIELD_ANY)
                fmt->field = sink_fmt_default.field;

        vimc_colorimetry_clamp(fmt);
}

static int vimc_sca_set_fmt(struct v4l2_subdev *sd,
                            struct v4l2_subdev_state *sd_state,
                            struct v4l2_subdev_format *fmt)
{
        struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *sink_fmt;
        struct v4l2_rect *crop_rect;

        if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                /* Do not change the format while stream is on */
                if (vsca->src_frame)
                        return -EBUSY;

                sink_fmt = &vsca->sink_fmt;
                crop_rect = &vsca->crop_rect;
        } else {
                sink_fmt = v4l2_subdev_get_try_format(sd, sd_state, 0);
                crop_rect = v4l2_subdev_get_try_crop(sd, sd_state, 0);
        }

        /*
         * Do not change the format of the source pad,
         * it is propagated from the sink
         */
        if (VIMC_IS_SRC(fmt->pad)) {
                fmt->format = *sink_fmt;
                fmt->format.width = crop_rect->width * sca_mult;
                fmt->format.height = crop_rect->height * sca_mult;
        } else {
                /* Set the new format in the sink pad */
                vimc_sca_adjust_sink_fmt(&fmt->format);

                dev_dbg(vsca->ved.dev, "%s: sink format update: "
                        "old:%dx%d (0x%x, %d, %d, %d, %d) "
                        "new:%dx%d (0x%x, %d, %d, %d, %d)\n", vsca->sd.name,
                        /* old */
                        sink_fmt->width, sink_fmt->height, sink_fmt->code,
                        sink_fmt->colorspace, sink_fmt->quantization,
                        sink_fmt->xfer_func, sink_fmt->ycbcr_enc,
                        /* new */
                        fmt->format.width, fmt->format.height, fmt->format.code,
                        fmt->format.colorspace, fmt->format.quantization,
                        fmt->format.xfer_func, fmt->format.ycbcr_enc);

                *sink_fmt = fmt->format;

                /* Do the crop, but respect the current bounds */
                vimc_sca_adjust_sink_crop(crop_rect, sink_fmt);
        }

        return 0;
}

static int vimc_sca_get_selection(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_selection *sel)
{
        struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *sink_fmt;
        struct v4l2_rect *crop_rect;

        if (VIMC_IS_SRC(sel->pad))
                return -EINVAL;

        if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                sink_fmt = &vsca->sink_fmt;
                crop_rect = &vsca->crop_rect;
        } else {
                sink_fmt = v4l2_subdev_get_try_format(sd, sd_state, 0);
                crop_rect = v4l2_subdev_get_try_crop(sd, sd_state, 0);
        }

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP:
                sel->r = *crop_rect;
                break;
        case V4L2_SEL_TGT_CROP_BOUNDS:
                sel->r = vimc_sca_get_crop_bound_sink(sink_fmt);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int vimc_sca_set_selection(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_selection *sel)
{
        struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *sink_fmt;
        struct v4l2_rect *crop_rect;

        if (VIMC_IS_SRC(sel->pad))
                return -EINVAL;

        if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                /* Do not change the format while stream is on */
                if (vsca->src_frame)
                        return -EBUSY;

                crop_rect = &vsca->crop_rect;
                sink_fmt = &vsca->sink_fmt;
        } else {
                crop_rect = v4l2_subdev_get_try_crop(sd, sd_state, 0);
                sink_fmt = v4l2_subdev_get_try_format(sd, sd_state, 0);
        }

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP:
                /* Do the crop, but respect the current bounds */
                vimc_sca_adjust_sink_crop(&sel->r, sink_fmt);
                *crop_rect = sel->r;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static const struct v4l2_subdev_pad_ops vimc_sca_pad_ops = {
        .init_cfg               = vimc_sca_init_cfg,
        .enum_mbus_code         = vimc_sca_enum_mbus_code,
        .enum_frame_size        = vimc_sca_enum_frame_size,
        .get_fmt                = vimc_sca_get_fmt,
        .set_fmt                = vimc_sca_set_fmt,
        .get_selection          = vimc_sca_get_selection,
        .set_selection          = vimc_sca_set_selection,
};

static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);

        if (enable) {
                const struct vimc_pix_map *vpix;
                unsigned int frame_size;

                if (vsca->src_frame)
                        return 0;

                /* Save the bytes per pixel of the sink */
                vpix = vimc_pix_map_by_code(vsca->sink_fmt.code);
                vsca->bpp = vpix->bpp;

                /* Calculate the width in bytes of the src frame */
                vsca->src_line_size = vsca->crop_rect.width *
                                      sca_mult * vsca->bpp;

                /* Calculate the frame size of the source pad */
                frame_size = vsca->src_line_size * vsca->crop_rect.height *
                             sca_mult;

                /* Allocate the frame buffer. Use vmalloc to be able to
                 * allocate a large amount of memory
                 */
                vsca->src_frame = vmalloc(frame_size);
                if (!vsca->src_frame)
                        return -ENOMEM;

        } else {
                if (!vsca->src_frame)
                        return 0;

                vfree(vsca->src_frame);
                vsca->src_frame = NULL;
        }

        return 0;
}

static const struct v4l2_subdev_video_ops vimc_sca_video_ops = {
        .s_stream = vimc_sca_s_stream,
};

static const struct v4l2_subdev_ops vimc_sca_ops = {
        .pad = &vimc_sca_pad_ops,
        .video = &vimc_sca_video_ops,
};

static void vimc_sca_fill_pix(u8 *const ptr,
                              const u8 *const pixel,
                              const unsigned int bpp)
{
        unsigned int i;

        /* copy the pixel to the pointer */
        for (i = 0; i < bpp; i++)
                ptr[i] = pixel[i];
}

static void vimc_sca_scale_pix(const struct vimc_sca_device *const vsca,
                               unsigned int lin, unsigned int col,
                               const u8 *const sink_frame)
{
        const struct v4l2_rect crop_rect = vsca->crop_rect;
        unsigned int i, j, index;
        const u8 *pixel;

        /* Point to the pixel value in position (lin, col) in the sink frame */
        index = VIMC_FRAME_INDEX(lin, col,
                                 vsca->sink_fmt.width,
                                 vsca->bpp);
        pixel = &sink_frame[index];

        dev_dbg(vsca->ved.dev,
                "sca: %s: --- scale_pix sink pos %dx%d, index %d ---\n",
                vsca->sd.name, lin, col, index);

        /* point to the place we are going to put the first pixel
         * in the scaled src frame
         */
        lin -= crop_rect.top;
        col -= crop_rect.left;
        index = VIMC_FRAME_INDEX(lin * sca_mult, col * sca_mult,
                                 crop_rect.width * sca_mult, vsca->bpp);

        dev_dbg(vsca->ved.dev, "sca: %s: scale_pix src pos %dx%d, index %d\n",
                vsca->sd.name, lin * sca_mult, col * sca_mult, index);

        /* Repeat this pixel mult times */
        for (i = 0; i < sca_mult; i++) {
                /* Iterate through each beginning of a
                 * pixel repetition in a line
                 */
                for (j = 0; j < sca_mult * vsca->bpp; j += vsca->bpp) {
                        dev_dbg(vsca->ved.dev,
                                "sca: %s: sca: scale_pix src pos %d\n",
                                vsca->sd.name, index + j);

                        /* copy the pixel to the position index + j */
                        vimc_sca_fill_pix(&vsca->src_frame[index + j],
                                          pixel, vsca->bpp);
                }

                /* move the index to the next line */
                index += vsca->src_line_size;
        }
}

static void vimc_sca_fill_src_frame(const struct vimc_sca_device *const vsca,
                                    const u8 *const sink_frame)
{
        const struct v4l2_rect r = vsca->crop_rect;
        unsigned int i, j;

        /* Scale each pixel from the original sink frame */
        /* TODO: implement scale down, only scale up is supported for now */
        for (i = r.top; i < r.top + r.height; i++)
                for (j = r.left; j < r.left + r.width; j++)
                        vimc_sca_scale_pix(vsca, i, j, sink_frame);
}

static void *vimc_sca_process_frame(struct vimc_ent_device *ved,
                                    const void *sink_frame)
{
        struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
                                                    ved);

        /* If the stream in this node is not active, just return */
        if (!vsca->src_frame)
                return ERR_PTR(-EINVAL);

        vimc_sca_fill_src_frame(vsca, sink_frame);

        return vsca->src_frame;
};

static void vimc_sca_release(struct vimc_ent_device *ved)
{
        struct vimc_sca_device *vsca =
                container_of(ved, struct vimc_sca_device, ved);

        media_entity_cleanup(vsca->ved.ent);
        kfree(vsca);
}

static struct vimc_ent_device *vimc_sca_add(struct vimc_device *vimc,
                                            const char *vcfg_name)
{
        struct v4l2_device *v4l2_dev = &vimc->v4l2_dev;
        struct vimc_sca_device *vsca;
        int ret;

        /* Allocate the vsca struct */
        vsca = kzalloc(sizeof(*vsca), GFP_KERNEL);
        if (!vsca)
                return ERR_PTR(-ENOMEM);

        /* Initialize ved and sd */
        vsca->pads[0].flags = MEDIA_PAD_FL_SINK;
        vsca->pads[1].flags = MEDIA_PAD_FL_SOURCE;

        ret = vimc_ent_sd_register(&vsca->ved, &vsca->sd, v4l2_dev,
                                   vcfg_name,
                                   MEDIA_ENT_F_PROC_VIDEO_SCALER, 2,
                                   vsca->pads, &vimc_sca_ops);
        if (ret) {
                kfree(vsca);
                return ERR_PTR(ret);
        }

        vsca->ved.process_frame = vimc_sca_process_frame;
        vsca->ved.dev = vimc->mdev.dev;

        /* Initialize the frame format */
        vsca->sink_fmt = sink_fmt_default;

        /* Initialize the crop selection */
        vsca->crop_rect = crop_rect_default;

        return &vsca->ved;
}

struct vimc_ent_type vimc_sca_type = {
        .add = vimc_sca_add,
        .release = vimc_sca_release
};