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

#include "vimc-common.h"

/* Pad identifier */
enum vimc_scaler_pad {
        VIMC_SCALER_SINK = 0,
        VIMC_SCALER_SRC = 1,
};

#define VIMC_SCALER_FMT_WIDTH_DEFAULT  640
#define VIMC_SCALER_FMT_HEIGHT_DEFAULT 480

struct vimc_scaler_device {
        struct vimc_ent_device ved;
        struct v4l2_subdev sd;
        struct media_pad pads[2];

        u8 *src_frame;

        /*
         * Virtual "hardware" configuration, filled when the stream starts or
         * when controls are set.
         */
        struct {
                struct v4l2_mbus_framefmt sink_fmt;
                struct v4l2_mbus_framefmt src_fmt;
                struct v4l2_rect sink_crop;
                unsigned int bpp;
        } hw;
};

static const struct v4l2_mbus_framefmt fmt_default = {
        .width = VIMC_SCALER_FMT_WIDTH_DEFAULT,
        .height = VIMC_SCALER_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_SCALER_FMT_WIDTH_DEFAULT,
        .height = VIMC_SCALER_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_scaler_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 int vimc_scaler_init_state(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state)
{
        struct v4l2_mbus_framefmt *mf;
        struct v4l2_rect *r;
        unsigned int i;

        for (i = 0; i < sd->entity.num_pads; i++) {
                mf = v4l2_subdev_state_get_format(sd_state, i);
                *mf = fmt_default;
        }

        r = v4l2_subdev_state_get_crop(sd_state, VIMC_SCALER_SINK);
        *r = crop_rect_default;

        return 0;
}

static int vimc_scaler_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_scaler_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;

        fse->max_width = VIMC_FRAME_MAX_WIDTH;
        fse->max_height = VIMC_FRAME_MAX_HEIGHT;

        return 0;
}

static int vimc_scaler_set_fmt(struct v4l2_subdev *sd,
                            struct v4l2_subdev_state *sd_state,
                            struct v4l2_subdev_format *format)
{
        struct vimc_scaler_device *vscaler = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *fmt;

        /* Do not change the active format while stream is on */
        if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE && vscaler->src_frame)
                return -EBUSY;

        fmt = v4l2_subdev_state_get_format(sd_state, format->pad);

        /*
         * The media bus code and colorspace can only be changed on the sink
         * pad, the source pad only follows.
         */
        if (format->pad == VIMC_SCALER_SINK) {
                const struct vimc_pix_map *vpix;

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

                /* Clamp the colorspace to valid values. */
                fmt->colorspace = format->format.colorspace;
                fmt->ycbcr_enc = format->format.ycbcr_enc;
                fmt->quantization = format->format.quantization;
                fmt->xfer_func = format->format.xfer_func;
                vimc_colorimetry_clamp(fmt);
        }

        /* Clamp and align the width and height */
        fmt->width = clamp_t(u32, format->format.width, VIMC_FRAME_MIN_WIDTH,
                             VIMC_FRAME_MAX_WIDTH) & ~1;
        fmt->height = clamp_t(u32, format->format.height, VIMC_FRAME_MIN_HEIGHT,
                              VIMC_FRAME_MAX_HEIGHT) & ~1;

        /*
         * Propagate the sink pad format to the crop rectangle and the source
         * pad.
         */
        if (format->pad == VIMC_SCALER_SINK) {
                struct v4l2_mbus_framefmt *src_fmt;
                struct v4l2_rect *crop;

                crop = v4l2_subdev_state_get_crop(sd_state, VIMC_SCALER_SINK);
                crop->width = fmt->width;
                crop->height = fmt->height;
                crop->top = 0;
                crop->left = 0;

                src_fmt = v4l2_subdev_state_get_format(sd_state, VIMC_SCALER_SRC);
                *src_fmt = *fmt;
        }

        format->format = *fmt;

        return 0;
}

static int vimc_scaler_get_selection(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_selection *sel)
{
        struct v4l2_mbus_framefmt *sink_fmt;

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

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP:
                sel->r = *v4l2_subdev_state_get_crop(sd_state, VIMC_SCALER_SINK);
                break;
        case V4L2_SEL_TGT_CROP_BOUNDS:
                sink_fmt = v4l2_subdev_state_get_format(sd_state, VIMC_SCALER_SINK);
                sel->r = vimc_scaler_get_crop_bound_sink(sink_fmt);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static void vimc_scaler_adjust_sink_crop(struct v4l2_rect *r,
                                      const struct v4l2_mbus_framefmt *sink_fmt)
{
        const struct v4l2_rect sink_rect =
                vimc_scaler_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_scaler_set_selection(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_selection *sel)
{
        struct vimc_scaler_device *vscaler = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *sink_fmt;
        struct v4l2_rect *crop_rect;

        /* Only support setting the crop of the sink pad */
        if (VIMC_IS_SRC(sel->pad) || sel->target != V4L2_SEL_TGT_CROP)
                return -EINVAL;

        if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE && vscaler->src_frame)
                return -EBUSY;

        crop_rect = v4l2_subdev_state_get_crop(sd_state, VIMC_SCALER_SINK);
        sink_fmt = v4l2_subdev_state_get_format(sd_state, VIMC_SCALER_SINK);
        vimc_scaler_adjust_sink_crop(&sel->r, sink_fmt);
        *crop_rect = sel->r;

        return 0;
}

static const struct v4l2_subdev_pad_ops vimc_scaler_pad_ops = {
        .enum_mbus_code         = vimc_scaler_enum_mbus_code,
        .enum_frame_size        = vimc_scaler_enum_frame_size,
        .get_fmt                = v4l2_subdev_get_fmt,
        .set_fmt                = vimc_scaler_set_fmt,
        .get_selection          = vimc_scaler_get_selection,
        .set_selection          = vimc_scaler_set_selection,
};

static int vimc_scaler_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct vimc_scaler_device *vscaler = v4l2_get_subdevdata(sd);

        if (enable) {
                struct v4l2_subdev_state *state;
                const struct v4l2_mbus_framefmt *format;
                const struct v4l2_rect *rect;
                unsigned int frame_size;

                if (vscaler->src_frame)
                        return 0;

                state = v4l2_subdev_lock_and_get_active_state(sd);

                /* Save the bytes per pixel of the sink. */
                format = v4l2_subdev_state_get_format(state, VIMC_SCALER_SINK);
                vscaler->hw.sink_fmt = *format;
                vscaler->hw.bpp = vimc_pix_map_by_code(format->code)->bpp;

                /* Calculate the frame size of the source pad. */
                format = v4l2_subdev_state_get_format(state, VIMC_SCALER_SRC);
                vscaler->hw.src_fmt = *format;
                frame_size = format->width * format->height * vscaler->hw.bpp;

                rect = v4l2_subdev_state_get_crop(state, VIMC_SCALER_SINK);
                vscaler->hw.sink_crop = *rect;

                v4l2_subdev_unlock_state(state);

                /*
                 * Allocate the frame buffer. Use vmalloc to be able to allocate
                 * a large amount of memory.
                 */
                vscaler->src_frame = vmalloc(frame_size);
                if (!vscaler->src_frame)
                        return -ENOMEM;
        } else {
                if (!vscaler->src_frame)
                        return 0;

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

        return 0;
}

static const struct v4l2_subdev_video_ops vimc_scaler_video_ops = {
        .s_stream = vimc_scaler_s_stream,
};

static const struct v4l2_subdev_ops vimc_scaler_ops = {
        .pad = &vimc_scaler_pad_ops,
        .video = &vimc_scaler_video_ops,
};

static const struct v4l2_subdev_internal_ops vimc_scaler_internal_ops = {
        .init_state = vimc_scaler_init_state,
};

static void vimc_scaler_fill_src_frame(const struct vimc_scaler_device *const vscaler,
                                    const u8 *const sink_frame)
{
        const struct v4l2_mbus_framefmt *sink_fmt = &vscaler->hw.sink_fmt;
        const struct v4l2_mbus_framefmt *src_fmt = &vscaler->hw.src_fmt;
        const struct v4l2_rect *r = &vscaler->hw.sink_crop;
        unsigned int src_x, src_y;
        u8 *walker = vscaler->src_frame;

        /* Set each pixel at the src_frame to its sink_frame equivalent */
        for (src_y = 0; src_y < src_fmt->height; src_y++) {
                unsigned int snk_y, y_offset;

                snk_y = (src_y * r->height) / src_fmt->height + r->top;
                y_offset = snk_y * sink_fmt->width * vscaler->hw.bpp;

                for (src_x = 0; src_x < src_fmt->width; src_x++) {
                        unsigned int snk_x, x_offset, index;

                        snk_x = (src_x * r->width) / src_fmt->width + r->left;
                        x_offset = snk_x * vscaler->hw.bpp;
                        index = y_offset + x_offset;
                        memcpy(walker, &sink_frame[index], vscaler->hw.bpp);
                        walker += vscaler->hw.bpp;
                }
        }
}

static void *vimc_scaler_process_frame(struct vimc_ent_device *ved,
                                    const void *sink_frame)
{
        struct vimc_scaler_device *vscaler = container_of(ved, struct vimc_scaler_device,
                                                    ved);

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

        vimc_scaler_fill_src_frame(vscaler, sink_frame);

        return vscaler->src_frame;
};

static void vimc_scaler_release(struct vimc_ent_device *ved)
{
        struct vimc_scaler_device *vscaler =
                container_of(ved, struct vimc_scaler_device, ved);

        v4l2_subdev_cleanup(&vscaler->sd);
        media_entity_cleanup(vscaler->ved.ent);
        kfree(vscaler);
}

static struct vimc_ent_device *vimc_scaler_add(struct vimc_device *vimc,
                                            const char *vcfg_name)
{
        struct v4l2_device *v4l2_dev = &vimc->v4l2_dev;
        struct vimc_scaler_device *vscaler;
        int ret;

        /* Allocate the vscaler struct */
        vscaler = kzalloc_obj(*vscaler);
        if (!vscaler)
                return ERR_PTR(-ENOMEM);

        /* Initialize ved and sd */
        vscaler->pads[VIMC_SCALER_SINK].flags = MEDIA_PAD_FL_SINK;
        vscaler->pads[VIMC_SCALER_SRC].flags = MEDIA_PAD_FL_SOURCE;

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

        vscaler->ved.process_frame = vimc_scaler_process_frame;
        vscaler->ved.dev = vimc->mdev.dev;

        return &vscaler->ved;
}

const struct vimc_ent_type vimc_scaler_type = {
        .add = vimc_scaler_add,
        .release = vimc_scaler_release
};