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

#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/vmalloc.h>
#include <linux/v4l2-mediabus.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/v4l2-subdev.h>

#include "vimc-common.h"

/* TODO: Add support for more output formats, we only support RGB888 for now. */
#define VIMC_DEBAYER_SOURCE_MBUS_FMT    MEDIA_BUS_FMT_RGB888_1X24

enum vimc_debayer_rgb_colors {
        VIMC_DEBAYER_RED = 0,
        VIMC_DEBAYER_GREEN = 1,
        VIMC_DEBAYER_BLUE = 2,
};

struct vimc_debayer_pix_map {
        u32 code;
        enum vimc_debayer_rgb_colors order[2][2];
};

struct vimc_debayer_device {
        struct vimc_ent_device ved;
        struct v4l2_subdev sd;
        struct v4l2_ctrl_handler hdl;
        struct media_pad pads[2];

        u8 *src_frame;

        void (*set_rgb_src)(struct vimc_debayer_device *vdebayer,
                            unsigned int lin, unsigned int col,
                            unsigned int rgb[3]);

        /*
         * Virtual "hardware" configuration, filled when the stream starts or
         * when controls are set.
         */
        struct {
                const struct vimc_debayer_pix_map *sink_pix_map;
                unsigned int sink_bpp;
                struct v4l2_area size;
                unsigned int mean_win_size;
                u32 src_code;
        } hw;
};

static const struct v4l2_mbus_framefmt sink_fmt_default = {
        .width = 640,
        .height = 480,
        .code = MEDIA_BUS_FMT_SRGGB8_1X8,
        .field = V4L2_FIELD_NONE,
        .colorspace = V4L2_COLORSPACE_SRGB,
};

static const u32 vimc_debayer_src_mbus_codes[] = {
        MEDIA_BUS_FMT_GBR888_1X24,
        MEDIA_BUS_FMT_BGR888_1X24,
        MEDIA_BUS_FMT_BGR888_3X8,
        MEDIA_BUS_FMT_RGB888_1X24,
        MEDIA_BUS_FMT_RGB888_2X12_BE,
        MEDIA_BUS_FMT_RGB888_2X12_LE,
        MEDIA_BUS_FMT_RGB888_3X8,
        MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
        MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,
        MEDIA_BUS_FMT_RGB888_1X32_PADHI,
};

static const struct vimc_debayer_pix_map vimc_debayer_pix_map_list[] = {
        {
                .code = MEDIA_BUS_FMT_SBGGR8_1X8,
                .order = { { VIMC_DEBAYER_BLUE, VIMC_DEBAYER_GREEN },
                           { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_RED } }
        },
        {
                .code = MEDIA_BUS_FMT_SGBRG8_1X8,
                .order = { { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_BLUE },
                           { VIMC_DEBAYER_RED, VIMC_DEBAYER_GREEN } }
        },
        {
                .code = MEDIA_BUS_FMT_SGRBG8_1X8,
                .order = { { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_RED },
                           { VIMC_DEBAYER_BLUE, VIMC_DEBAYER_GREEN } }
        },
        {
                .code = MEDIA_BUS_FMT_SRGGB8_1X8,
                .order = { { VIMC_DEBAYER_RED, VIMC_DEBAYER_GREEN },
                           { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_BLUE } }
        },
        {
                .code = MEDIA_BUS_FMT_SBGGR10_1X10,
                .order = { { VIMC_DEBAYER_BLUE, VIMC_DEBAYER_GREEN },
                           { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_RED } }
        },
        {
                .code = MEDIA_BUS_FMT_SGBRG10_1X10,
                .order = { { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_BLUE },
                           { VIMC_DEBAYER_RED, VIMC_DEBAYER_GREEN } }
        },
        {
                .code = MEDIA_BUS_FMT_SGRBG10_1X10,
                .order = { { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_RED },
                           { VIMC_DEBAYER_BLUE, VIMC_DEBAYER_GREEN } }
        },
        {
                .code = MEDIA_BUS_FMT_SRGGB10_1X10,
                .order = { { VIMC_DEBAYER_RED, VIMC_DEBAYER_GREEN },
                           { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_BLUE } }
        },
        {
                .code = MEDIA_BUS_FMT_SBGGR12_1X12,
                .order = { { VIMC_DEBAYER_BLUE, VIMC_DEBAYER_GREEN },
                           { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_RED } }
        },
        {
                .code = MEDIA_BUS_FMT_SGBRG12_1X12,
                .order = { { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_BLUE },
                           { VIMC_DEBAYER_RED, VIMC_DEBAYER_GREEN } }
        },
        {
                .code = MEDIA_BUS_FMT_SGRBG12_1X12,
                .order = { { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_RED },
                           { VIMC_DEBAYER_BLUE, VIMC_DEBAYER_GREEN } }
        },
        {
                .code = MEDIA_BUS_FMT_SRGGB12_1X12,
                .order = { { VIMC_DEBAYER_RED, VIMC_DEBAYER_GREEN },
                           { VIMC_DEBAYER_GREEN, VIMC_DEBAYER_BLUE } }
        },
};

static const struct vimc_debayer_pix_map *vimc_debayer_pix_map_by_code(u32 code)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(vimc_debayer_pix_map_list); i++)
                if (vimc_debayer_pix_map_list[i].code == code)
                        return &vimc_debayer_pix_map_list[i];

        return NULL;
}

static bool vimc_debayer_src_code_is_valid(u32 code)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(vimc_debayer_src_mbus_codes); i++)
                if (vimc_debayer_src_mbus_codes[i] == code)
                        return true;

        return false;
}

static int vimc_debayer_init_state(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_state *sd_state)
{
        struct v4l2_mbus_framefmt *mf;

        mf = v4l2_subdev_state_get_format(sd_state, 0);
        *mf = sink_fmt_default;

        mf = v4l2_subdev_state_get_format(sd_state, 1);
        *mf = sink_fmt_default;
        mf->code = VIMC_DEBAYER_SOURCE_MBUS_FMT;

        return 0;
}

static int vimc_debayer_enum_mbus_code(struct v4l2_subdev *sd,
                                       struct v4l2_subdev_state *sd_state,
                                       struct v4l2_subdev_mbus_code_enum *code)
{
        if (VIMC_IS_SRC(code->pad)) {
                if (code->index >= ARRAY_SIZE(vimc_debayer_src_mbus_codes))
                        return -EINVAL;

                code->code = vimc_debayer_src_mbus_codes[code->index];
        } else {
                if (code->index >= ARRAY_SIZE(vimc_debayer_pix_map_list))
                        return -EINVAL;

                code->code = vimc_debayer_pix_map_list[code->index].code;
        }

        return 0;
}

static int vimc_debayer_enum_frame_size(struct v4l2_subdev *sd,
                                        struct v4l2_subdev_state *sd_state,
                                        struct v4l2_subdev_frame_size_enum *fse)
{
        if (fse->index)
                return -EINVAL;

        if (VIMC_IS_SINK(fse->pad)) {
                const struct vimc_debayer_pix_map *vpix =
                        vimc_debayer_pix_map_by_code(fse->code);

                if (!vpix)
                        return -EINVAL;
        } else if (!vimc_debayer_src_code_is_valid(fse->code)) {
                return -EINVAL;
        }

        fse->min_width = VIMC_FRAME_MIN_WIDTH;
        fse->max_width = VIMC_FRAME_MAX_WIDTH;
        fse->min_height = VIMC_FRAME_MIN_HEIGHT;
        fse->max_height = VIMC_FRAME_MAX_HEIGHT;

        return 0;
}

static void vimc_debayer_adjust_sink_fmt(struct v4l2_mbus_framefmt *fmt)
{
        const struct vimc_debayer_pix_map *vpix;

        /* Don't accept a code that is not on the debayer table */
        vpix = vimc_debayer_pix_map_by_code(fmt->code);
        if (!vpix)
                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_debayer_set_fmt(struct v4l2_subdev *sd,
                                struct v4l2_subdev_state *sd_state,
                                struct v4l2_subdev_format *fmt)
{
        struct vimc_debayer_device *vdebayer = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *format;

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

        /*
         * Do not change the format of the source pad, it is propagated from
         * the sink.
         */
        if (VIMC_IS_SRC(fmt->pad))
                return v4l2_subdev_get_fmt(sd, sd_state, fmt);

        /* Set the new format in the sink pad. */
        vimc_debayer_adjust_sink_fmt(&fmt->format);

        format = v4l2_subdev_state_get_format(sd_state, 0);

        dev_dbg(vdebayer->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", vdebayer->sd.name,
                /* old */
                format->width, format->height, format->code,
                format->colorspace, format->quantization,
                format->xfer_func, format->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);

        *format = fmt->format;

        /* Propagate the format to the source pad. */
        format = v4l2_subdev_state_get_format(sd_state, 1);
        *format = fmt->format;
        format->code = VIMC_DEBAYER_SOURCE_MBUS_FMT;

        return 0;
}

static const struct v4l2_subdev_pad_ops vimc_debayer_pad_ops = {
        .enum_mbus_code         = vimc_debayer_enum_mbus_code,
        .enum_frame_size        = vimc_debayer_enum_frame_size,
        .get_fmt                = v4l2_subdev_get_fmt,
        .set_fmt                = vimc_debayer_set_fmt,
};

static void vimc_debayer_process_rgb_frame(struct vimc_debayer_device *vdebayer,
                                           unsigned int lin,
                                           unsigned int col,
                                           unsigned int rgb[3])
{
        const struct vimc_pix_map *vpix;
        unsigned int i, index;

        vpix = vimc_pix_map_by_code(vdebayer->hw.src_code);
        index = VIMC_FRAME_INDEX(lin, col, vdebayer->hw.size.width, 3);
        for (i = 0; i < 3; i++) {
                switch (vpix->pixelformat) {
                case V4L2_PIX_FMT_RGB24:
                        vdebayer->src_frame[index + i] = rgb[i];
                        break;
                case V4L2_PIX_FMT_BGR24:
                        vdebayer->src_frame[index + i] = rgb[2 - i];
                        break;
                }
        }
}

static int vimc_debayer_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct vimc_debayer_device *vdebayer = v4l2_get_subdevdata(sd);

        if (enable) {
                const struct v4l2_mbus_framefmt *sink_fmt;
                const struct v4l2_mbus_framefmt *src_fmt;
                struct v4l2_subdev_state *state;
                const struct vimc_pix_map *vpix;
                unsigned int frame_size;

                if (vdebayer->src_frame)
                        return 0;

                state = v4l2_subdev_lock_and_get_active_state(sd);
                sink_fmt = v4l2_subdev_state_get_format(state, 0);
                src_fmt = v4l2_subdev_state_get_format(state, 1);

                /* Calculate the frame size of the source pad */
                vpix = vimc_pix_map_by_code(src_fmt->code);
                frame_size = src_fmt->width * src_fmt->height * vpix->bpp;

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

                /* Get the corresponding pixel map from the table */
                vdebayer->hw.sink_pix_map =
                        vimc_debayer_pix_map_by_code(sink_fmt->code);

                vdebayer->hw.size.width = sink_fmt->width;
                vdebayer->hw.size.height = sink_fmt->height;

                vdebayer->hw.src_code = src_fmt->code;

                v4l2_subdev_unlock_state(state);

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

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

        return 0;
}

static const struct v4l2_subdev_core_ops vimc_debayer_core_ops = {
        .log_status = v4l2_ctrl_subdev_log_status,
        .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
        .unsubscribe_event = v4l2_event_subdev_unsubscribe,
};

static const struct v4l2_subdev_video_ops vimc_debayer_video_ops = {
        .s_stream = vimc_debayer_s_stream,
};

static const struct v4l2_subdev_ops vimc_debayer_ops = {
        .core = &vimc_debayer_core_ops,
        .pad = &vimc_debayer_pad_ops,
        .video = &vimc_debayer_video_ops,
};

static const struct v4l2_subdev_internal_ops vimc_debayer_internal_ops = {
        .init_state = vimc_debayer_init_state,
};

static unsigned int vimc_debayer_get_val(const u8 *bytes,
                                         const unsigned int n_bytes)
{
        unsigned int i;
        unsigned int acc = 0;

        for (i = 0; i < n_bytes; i++)
                acc = acc + (bytes[i] << (8 * i));

        return acc;
}

static void vimc_debayer_calc_rgb_sink(struct vimc_debayer_device *vdebayer,
                                       const u8 *frame,
                                       const unsigned int lin,
                                       const unsigned int col,
                                       unsigned int rgb[3])
{
        unsigned int i, seek, wlin, wcol;
        unsigned int n_rgb[3] = {0, 0, 0};

        for (i = 0; i < 3; i++)
                rgb[i] = 0;

        /*
         * Calculate how many we need to subtract to get to the pixel in
         * the top left corner of the mean window (considering the current
         * pixel as the center)
         */
        seek = vdebayer->hw.mean_win_size / 2;

        /* Sum the values of the colors in the mean window */

        dev_dbg(vdebayer->ved.dev,
                "deb: %s: --- Calc pixel %dx%d, window mean %d, seek %d ---\n",
                vdebayer->sd.name, lin, col, vdebayer->hw.size.height, seek);

        /*
         * Iterate through all the lines in the mean window, start
         * with zero if the pixel is outside the frame and don't pass
         * the height when the pixel is in the bottom border of the
         * frame
         */
        for (wlin = seek > lin ? 0 : lin - seek;
             wlin < lin + seek + 1 && wlin < vdebayer->hw.size.height;
             wlin++) {

                /*
                 * Iterate through all the columns in the mean window, start
                 * with zero if the pixel is outside the frame and don't pass
                 * the width when the pixel is in the right border of the
                 * frame
                 */
                for (wcol = seek > col ? 0 : col - seek;
                     wcol < col + seek + 1 && wcol < vdebayer->hw.size.width;
                     wcol++) {
                        enum vimc_debayer_rgb_colors color;
                        unsigned int index;

                        /* Check which color this pixel is */
                        color = vdebayer->hw.sink_pix_map->order[wlin % 2][wcol % 2];

                        index = VIMC_FRAME_INDEX(wlin, wcol,
                                                 vdebayer->hw.size.width,
                                                 vdebayer->hw.sink_bpp);

                        dev_dbg(vdebayer->ved.dev,
                                "deb: %s: RGB CALC: frame index %d, win pos %dx%d, color %d\n",
                                vdebayer->sd.name, index, wlin, wcol, color);

                        /* Get its value */
                        rgb[color] = rgb[color] +
                                vimc_debayer_get_val(&frame[index],
                                                     vdebayer->hw.sink_bpp);

                        /* Save how many values we already added */
                        n_rgb[color]++;

                        dev_dbg(vdebayer->ved.dev, "deb: %s: RGB CALC: val %d, n %d\n",
                                vdebayer->sd.name, rgb[color], n_rgb[color]);
                }
        }

        /* Calculate the mean */
        for (i = 0; i < 3; i++) {
                dev_dbg(vdebayer->ved.dev,
                        "deb: %s: PRE CALC: %dx%d Color %d, val %d, n %d\n",
                        vdebayer->sd.name, lin, col, i, rgb[i], n_rgb[i]);

                if (n_rgb[i])
                        rgb[i] = rgb[i] / n_rgb[i];

                dev_dbg(vdebayer->ved.dev,
                        "deb: %s: FINAL CALC: %dx%d Color %d, val %d\n",
                        vdebayer->sd.name, lin, col, i, rgb[i]);
        }
}

static void *vimc_debayer_process_frame(struct vimc_ent_device *ved,
                                        const void *sink_frame)
{
        struct vimc_debayer_device *vdebayer =
                container_of(ved, struct vimc_debayer_device, ved);

        unsigned int rgb[3];
        unsigned int i, j;

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

        for (i = 0; i < vdebayer->hw.size.height; i++)
                for (j = 0; j < vdebayer->hw.size.width; j++) {
                        vimc_debayer_calc_rgb_sink(vdebayer, sink_frame, i, j, rgb);
                        vdebayer->set_rgb_src(vdebayer, i, j, rgb);
                }

        return vdebayer->src_frame;
}

static int vimc_debayer_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct vimc_debayer_device *vdebayer =
                container_of(ctrl->handler, struct vimc_debayer_device, hdl);

        switch (ctrl->id) {
        case VIMC_CID_MEAN_WIN_SIZE:
                vdebayer->hw.mean_win_size = ctrl->val;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static const struct v4l2_ctrl_ops vimc_debayer_ctrl_ops = {
        .s_ctrl = vimc_debayer_s_ctrl,
};

static void vimc_debayer_release(struct vimc_ent_device *ved)
{
        struct vimc_debayer_device *vdebayer =
                container_of(ved, struct vimc_debayer_device, ved);

        v4l2_ctrl_handler_free(&vdebayer->hdl);
        v4l2_subdev_cleanup(&vdebayer->sd);
        media_entity_cleanup(vdebayer->ved.ent);
        kfree(vdebayer);
}

static const struct v4l2_ctrl_config vimc_debayer_ctrl_class = {
        .flags = V4L2_CTRL_FLAG_READ_ONLY | V4L2_CTRL_FLAG_WRITE_ONLY,
        .id = VIMC_CID_VIMC_CLASS,
        .name = "VIMC Controls",
        .type = V4L2_CTRL_TYPE_CTRL_CLASS,
};

static const struct v4l2_ctrl_config vimc_debayer_ctrl_mean_win_size = {
        .ops = &vimc_debayer_ctrl_ops,
        .id = VIMC_CID_MEAN_WIN_SIZE,
        .name = "Debayer Mean Window Size",
        .type = V4L2_CTRL_TYPE_INTEGER,
        .min = 1,
        .max = 25,
        .step = 2,
        .def = 3,
};

static struct vimc_ent_device *vimc_debayer_add(struct vimc_device *vimc,
                                                const char *vcfg_name)
{
        struct v4l2_device *v4l2_dev = &vimc->v4l2_dev;
        struct vimc_debayer_device *vdebayer;
        int ret;

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

        /* Create controls: */
        v4l2_ctrl_handler_init(&vdebayer->hdl, 2);
        v4l2_ctrl_new_custom(&vdebayer->hdl, &vimc_debayer_ctrl_class, NULL);
        v4l2_ctrl_new_custom(&vdebayer->hdl, &vimc_debayer_ctrl_mean_win_size, NULL);
        vdebayer->sd.ctrl_handler = &vdebayer->hdl;
        if (vdebayer->hdl.error) {
                ret = vdebayer->hdl.error;
                goto err_free_vdebayer;
        }

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

        ret = vimc_ent_sd_register(&vdebayer->ved, &vdebayer->sd, v4l2_dev,
                                   vcfg_name,
                                   MEDIA_ENT_F_PROC_VIDEO_PIXEL_ENC_CONV, 2,
                                   vdebayer->pads, &vimc_debayer_internal_ops,
                                   &vimc_debayer_ops);
        if (ret)
                goto err_free_hdl;

        vdebayer->ved.process_frame = vimc_debayer_process_frame;
        vdebayer->ved.dev = vimc->mdev.dev;
        vdebayer->hw.mean_win_size = vimc_debayer_ctrl_mean_win_size.def;

        vdebayer->set_rgb_src = vimc_debayer_process_rgb_frame;

        return &vdebayer->ved;

err_free_hdl:
        v4l2_ctrl_handler_free(&vdebayer->hdl);
err_free_vdebayer:
        kfree(vdebayer);

        return ERR_PTR(ret);
}

const struct vimc_ent_type vimc_debayer_type = {
        .add = vimc_debayer_add,
        .release = vimc_debayer_release
};