// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) Collabora, Ltd.
 *
 * Based on GSPCA and CODA drivers:
 * Copyright (C) Jean-Francois Moine (http://moinejf.free.fr)
 * Copyright (C) 2014 Philipp Zabel, Pengutronix
 */

#include <linux/align.h>
#include <linux/build_bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <media/v4l2-jpeg.h>
#include "hantro_jpeg.h"
#include "hantro.h"

#define LUMA_QUANT_OFF          25
#define CHROMA_QUANT_OFF        90
#define HEIGHT_OFF              159
#define WIDTH_OFF               161

#define HUFF_LUMA_DC_OFF        178
#define HUFF_LUMA_AC_OFF        211
#define HUFF_CHROMA_DC_OFF      394
#define HUFF_CHROMA_AC_OFF      427

static const u32 hw_reorder[] = {
         0,  8, 16, 24,  1,  9, 17, 25,
        32, 40, 48, 56, 33, 41, 49, 57,
         2, 10, 18, 26,  3, 11, 19, 27,
        34, 42, 50, 58, 35, 43, 51, 59,
         4, 12, 20, 28,  5, 13, 21, 29,
        36, 44, 52, 60, 37, 45, 53, 61,
         6, 14, 22, 30,  7, 15, 23, 31,
        38, 46, 54, 62, 39, 47, 55, 63
};

/* For simplicity, we keep a pre-formatted JPEG header,
 * and we'll use fixed offsets to change the width, height
 * quantization tables, etc.
 */
static const unsigned char hantro_jpeg_header[] = {
        /* SOI */
        0xff, 0xd8,

        /* JFIF-APP0 */
        0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46,
        0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x00, 0x01,
        0x00, 0x00,

        /* DQT */
        0xff, 0xdb, 0x00, 0x84,

        0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

        0x01,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

        /* SOF */
        0xff, 0xc0, 0x00, 0x11, 0x08, 0x00, 0xf0, 0x01,
        0x40, 0x03, 0x01, 0x22, 0x00, 0x02, 0x11, 0x01,
        0x03, 0x11, 0x01,

        /* DHT */
        0xff, 0xc4, 0x00, 0x1f, 0x00,

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00,

        /* DHT */
        0xff, 0xc4, 0x00, 0xb5, 0x10,

        0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

        /* DHT */
        0xff, 0xc4, 0x00, 0x1f, 0x01,

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00,

        /* DHT */
        0xff, 0xc4, 0x00, 0xb5, 0x11,

        0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

        /* COM */
        0xff, 0xfe, 0x00, 0x03, 0x00,

        /* SOS */
        0xff, 0xda, 0x00, 0x0c, 0x03, 0x01, 0x00, 0x02,
        0x11, 0x03, 0x11, 0x00, 0x3f, 0x00,
};

/*
 * JPEG_HEADER_SIZE is used in other parts of the driver in lieu of
 * "sizeof(hantro_jpeg_header)". The two must be equal.
 */
static_assert(sizeof(hantro_jpeg_header) == JPEG_HEADER_SIZE);

/*
 * hantro_jpeg_header is padded with a COM segment, so that the payload
 * of the SOS segment (the entropy-encoded image scan), which should
 * trail the whole header, is 8-byte aligned for the hardware to write
 * to directly.
 */
static_assert(IS_ALIGNED(sizeof(hantro_jpeg_header), 8),
              "Hantro JPEG header size needs to be 8-byte aligned.");

static unsigned char jpeg_scale_qp(const unsigned char qp, int scale)
{
        unsigned int temp;

        temp = DIV_ROUND_CLOSEST((unsigned int)qp * scale, 100);
        if (temp <= 0)
                temp = 1;
        if (temp > 255)
                temp = 255;

        return (unsigned char)temp;
}

static void
jpeg_scale_quant_table(unsigned char *file_q_tab,
                       unsigned char *reordered_q_tab,
                       const unsigned char *tab, int scale)
{
        int i;

        BUILD_BUG_ON(ARRAY_SIZE(v4l2_jpeg_zigzag_scan_index) != JPEG_QUANT_SIZE);
        BUILD_BUG_ON(ARRAY_SIZE(hw_reorder) != JPEG_QUANT_SIZE);

        for (i = 0; i < JPEG_QUANT_SIZE; i++) {
                file_q_tab[i] = jpeg_scale_qp(tab[v4l2_jpeg_zigzag_scan_index[i]], scale);
                reordered_q_tab[i] = jpeg_scale_qp(tab[hw_reorder[i]], scale);
        }
}

static void jpeg_set_quality(struct hantro_jpeg_ctx *ctx)
{
        int scale;
        /*
         * Non-linear scaling factor:
         * [5,50] -> [1000..100], [51,100] -> [98..0]
         */
        if (ctx->quality < 50)
                scale = 5000 / ctx->quality;
        else
                scale = 200 - 2 * ctx->quality;

        BUILD_BUG_ON(ARRAY_SIZE(v4l2_jpeg_ref_table_luma_qt) != JPEG_QUANT_SIZE);
        BUILD_BUG_ON(ARRAY_SIZE(v4l2_jpeg_ref_table_chroma_qt) != JPEG_QUANT_SIZE);
        BUILD_BUG_ON(ARRAY_SIZE(ctx->hw_luma_qtable) != JPEG_QUANT_SIZE);
        BUILD_BUG_ON(ARRAY_SIZE(ctx->hw_chroma_qtable) != JPEG_QUANT_SIZE);

        jpeg_scale_quant_table(ctx->buffer + LUMA_QUANT_OFF,
                               ctx->hw_luma_qtable,
                               (const unsigned char *)v4l2_jpeg_ref_table_luma_qt, scale);
        jpeg_scale_quant_table(ctx->buffer + CHROMA_QUANT_OFF,
                               ctx->hw_chroma_qtable,
                               (const unsigned char *)v4l2_jpeg_ref_table_chroma_qt, scale);
}

void hantro_jpeg_header_assemble(struct hantro_jpeg_ctx *ctx)
{
        char *buf = ctx->buffer;

        memcpy(buf, hantro_jpeg_header,
               sizeof(hantro_jpeg_header));

        buf[HEIGHT_OFF + 0] = ctx->height >> 8;
        buf[HEIGHT_OFF + 1] = ctx->height;
        buf[WIDTH_OFF + 0] = ctx->width >> 8;
        buf[WIDTH_OFF + 1] = ctx->width;

        memcpy(buf + HUFF_LUMA_DC_OFF, v4l2_jpeg_ref_table_luma_dc_ht, V4L2_JPEG_REF_HT_DC_LEN);
        memcpy(buf + HUFF_LUMA_AC_OFF, v4l2_jpeg_ref_table_luma_ac_ht, V4L2_JPEG_REF_HT_AC_LEN);
        memcpy(buf + HUFF_CHROMA_DC_OFF, v4l2_jpeg_ref_table_chroma_dc_ht, V4L2_JPEG_REF_HT_DC_LEN);
        memcpy(buf + HUFF_CHROMA_AC_OFF, v4l2_jpeg_ref_table_chroma_ac_ht, V4L2_JPEG_REF_HT_AC_LEN);

        jpeg_set_quality(ctx);
}