// SPDX-License-Identifier: GPL-2.0

/*
 *  ATI Mach64 Hardware Acceleration
 */

#include <linux/delay.h>
#include <linux/unaligned.h>
#include <linux/fb.h>
#include <video/mach64.h>
#include "atyfb.h"

    /*
     *  Generic Mach64 routines
     */

/* this is for DMA GUI engine! work in progress */
typedef struct {
        u32 frame_buf_offset;
        u32 system_mem_addr;
        u32 command;
        u32 reserved;
} BM_DESCRIPTOR_ENTRY;

#define LAST_DESCRIPTOR (1 << 31)
#define SYSTEM_TO_FRAME_BUFFER 0

static u32 rotation24bpp(u32 dx, u32 direction)
{
        u32 rotation;
        if (direction & DST_X_LEFT_TO_RIGHT) {
                rotation = (dx / 4) % 6;
        } else {
                rotation = ((dx + 2) / 4) % 6;
        }

        return ((rotation << 8) | DST_24_ROTATION_ENABLE);
}

void aty_reset_engine(struct atyfb_par *par)
{
        /* reset engine */
        aty_st_le32(GEN_TEST_CNTL,
                aty_ld_le32(GEN_TEST_CNTL, par) &
                ~(GUI_ENGINE_ENABLE | HWCURSOR_ENABLE), par);
        /* enable engine */
        aty_st_le32(GEN_TEST_CNTL,
                aty_ld_le32(GEN_TEST_CNTL, par) | GUI_ENGINE_ENABLE, par);
        /* ensure engine is not locked up by clearing any FIFO or */
        /* HOST errors */
        aty_st_le32(BUS_CNTL,
                aty_ld_le32(BUS_CNTL, par) | BUS_HOST_ERR_ACK | BUS_FIFO_ERR_ACK, par);

        par->fifo_space = 0;
}

static void reset_GTC_3D_engine(const struct atyfb_par *par)
{
        aty_st_le32(SCALE_3D_CNTL, 0xc0, par);
        mdelay(GTC_3D_RESET_DELAY);
        aty_st_le32(SETUP_CNTL, 0x00, par);
        mdelay(GTC_3D_RESET_DELAY);
        aty_st_le32(SCALE_3D_CNTL, 0x00, par);
        mdelay(GTC_3D_RESET_DELAY);
}

void aty_init_engine(struct atyfb_par *par, struct fb_info *info)
{
        u32 pitch_value;
        u32 vxres;

        /* determine modal information from global mode structure */
        pitch_value = info->fix.line_length / (info->var.bits_per_pixel / 8);
        vxres = info->var.xres_virtual;

        if (info->var.bits_per_pixel == 24) {
                /* In 24 bpp, the engine is in 8 bpp - this requires that all */
                /* horizontal coordinates and widths must be adjusted */
                pitch_value *= 3;
                vxres *= 3;
        }

        /* On GTC (RagePro), we need to reset the 3D engine before */
        if (M64_HAS(RESET_3D))
                reset_GTC_3D_engine(par);

        /* Reset engine, enable, and clear any engine errors */
        aty_reset_engine(par);
        /* Ensure that vga page pointers are set to zero - the upper */
        /* page pointers are set to 1 to handle overflows in the */
        /* lower page */
        aty_st_le32(MEM_VGA_WP_SEL, 0x00010000, par);
        aty_st_le32(MEM_VGA_RP_SEL, 0x00010000, par);

        /* ---- Setup standard engine context ---- */

        /* All GUI registers here are FIFOed - therefore, wait for */
        /* the appropriate number of empty FIFO entries */
        wait_for_fifo(14, par);

        /* enable all registers to be loaded for context loads */
        aty_st_le32(CONTEXT_MASK, 0xFFFFFFFF, par);

        /* set destination pitch to modal pitch, set offset to zero */
        aty_st_le32(DST_OFF_PITCH, (pitch_value / 8) << 22, par);

        /* zero these registers (set them to a known state) */
        aty_st_le32(DST_Y_X, 0, par);
        aty_st_le32(DST_HEIGHT, 0, par);
        aty_st_le32(DST_BRES_ERR, 0, par);
        aty_st_le32(DST_BRES_INC, 0, par);
        aty_st_le32(DST_BRES_DEC, 0, par);

        /* set destination drawing attributes */
        aty_st_le32(DST_CNTL, DST_LAST_PEL | DST_Y_TOP_TO_BOTTOM |
                    DST_X_LEFT_TO_RIGHT, par);

        /* set source pitch to modal pitch, set offset to zero */
        aty_st_le32(SRC_OFF_PITCH, (pitch_value / 8) << 22, par);

        /* set these registers to a known state */
        aty_st_le32(SRC_Y_X, 0, par);
        aty_st_le32(SRC_HEIGHT1_WIDTH1, 1, par);
        aty_st_le32(SRC_Y_X_START, 0, par);
        aty_st_le32(SRC_HEIGHT2_WIDTH2, 1, par);

        /* set source pixel retrieving attributes */
        aty_st_le32(SRC_CNTL, SRC_LINE_X_LEFT_TO_RIGHT, par);

        /* set host attributes */
        wait_for_fifo(13, par);
        aty_st_le32(HOST_CNTL, HOST_BYTE_ALIGN, par);

        /* set pattern attributes */
        aty_st_le32(PAT_REG0, 0, par);
        aty_st_le32(PAT_REG1, 0, par);
        aty_st_le32(PAT_CNTL, 0, par);

        /* set scissors to modal size */
        aty_st_le32(SC_LEFT, 0, par);
        aty_st_le32(SC_TOP, 0, par);
        aty_st_le32(SC_BOTTOM, par->crtc.vyres - 1, par);
        aty_st_le32(SC_RIGHT, vxres - 1, par);

        /* set background color to minimum value (usually BLACK) */
        aty_st_le32(DP_BKGD_CLR, 0, par);

        /* set foreground color to maximum value (usually WHITE) */
        aty_st_le32(DP_FRGD_CLR, 0xFFFFFFFF, par);

        /* set write mask to effect all pixel bits */
        aty_st_le32(DP_WRITE_MASK, 0xFFFFFFFF, par);

        /* set foreground mix to overpaint and background mix to */
        /* no-effect */
        aty_st_le32(DP_MIX, FRGD_MIX_S | BKGD_MIX_D, par);

        /* set primary source pixel channel to foreground color */
        /* register */
        aty_st_le32(DP_SRC, FRGD_SRC_FRGD_CLR, par);

        /* set compare functionality to false (no-effect on */
        /* destination) */
        wait_for_fifo(3, par);
        aty_st_le32(CLR_CMP_CLR, 0, par);
        aty_st_le32(CLR_CMP_MASK, 0xFFFFFFFF, par);
        aty_st_le32(CLR_CMP_CNTL, 0, par);

        /* set pixel depth */
        wait_for_fifo(2, par);
        aty_st_le32(DP_PIX_WIDTH, par->crtc.dp_pix_width, par);
        aty_st_le32(DP_CHAIN_MASK, par->crtc.dp_chain_mask, par);

        wait_for_fifo(5, par);
        aty_st_le32(SCALE_3D_CNTL, 0, par);
        aty_st_le32(Z_CNTL, 0, par);
        aty_st_le32(CRTC_INT_CNTL, aty_ld_le32(CRTC_INT_CNTL, par) & ~0x20,
                    par);
        aty_st_le32(GUI_TRAJ_CNTL, 0x100023, par);

        /* insure engine is idle before leaving */
        wait_for_idle(par);
}

    /*
     *  Accelerated functions
     */

static inline void draw_rect(s16 x, s16 y, u16 width, u16 height,
                             struct atyfb_par *par)
{
        /* perform rectangle fill */
        wait_for_fifo(2, par);
        aty_st_le32(DST_Y_X, (x << 16) | y, par);
        aty_st_le32(DST_HEIGHT_WIDTH, (width << 16) | height, par);
        par->blitter_may_be_busy = 1;
}

void atyfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
        struct atyfb_par *par = (struct atyfb_par *) info->par;
        u32 dy = area->dy, sy = area->sy, direction = DST_LAST_PEL;
        u32 sx = area->sx, dx = area->dx, width = area->width, rotation = 0;

        if (par->asleep)
                return;
        if (!area->width || !area->height)
                return;
        if (!par->accel_flags) {
                cfb_copyarea(info, area);
                return;
        }

        if (info->var.bits_per_pixel == 24) {
                /* In 24 bpp, the engine is in 8 bpp - this requires that all */
                /* horizontal coordinates and widths must be adjusted */
                sx *= 3;
                dx *= 3;
                width *= 3;
        }

        if (area->sy < area->dy) {
                dy += area->height - 1;
                sy += area->height - 1;
        } else
                direction |= DST_Y_TOP_TO_BOTTOM;

        if (sx < dx) {
                dx += width - 1;
                sx += width - 1;
        } else
                direction |= DST_X_LEFT_TO_RIGHT;

        if (info->var.bits_per_pixel == 24) {
                rotation = rotation24bpp(dx, direction);
        }

        wait_for_fifo(5, par);
        aty_st_le32(DP_PIX_WIDTH, par->crtc.dp_pix_width, par);
        aty_st_le32(DP_SRC, FRGD_SRC_BLIT, par);
        aty_st_le32(SRC_Y_X, (sx << 16) | sy, par);
        aty_st_le32(SRC_HEIGHT1_WIDTH1, (width << 16) | area->height, par);
        aty_st_le32(DST_CNTL, direction | rotation, par);
        draw_rect(dx, dy, width, area->height, par);
}

void atyfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
        struct atyfb_par *par = (struct atyfb_par *) info->par;
        u32 color, dx = rect->dx, width = rect->width, rotation = 0;

        if (par->asleep)
                return;
        if (!rect->width || !rect->height)
                return;
        if (!par->accel_flags) {
                cfb_fillrect(info, rect);
                return;
        }

        if (info->fix.visual == FB_VISUAL_TRUECOLOR ||
            info->fix.visual == FB_VISUAL_DIRECTCOLOR)
                color = ((u32 *)(info->pseudo_palette))[rect->color];
        else
                color = rect->color;

        if (info->var.bits_per_pixel == 24) {
                /* In 24 bpp, the engine is in 8 bpp - this requires that all */
                /* horizontal coordinates and widths must be adjusted */
                dx *= 3;
                width *= 3;
                rotation = rotation24bpp(dx, DST_X_LEFT_TO_RIGHT);
        }

        wait_for_fifo(4, par);
        aty_st_le32(DP_PIX_WIDTH, par->crtc.dp_pix_width, par);
        aty_st_le32(DP_FRGD_CLR, color, par);
        aty_st_le32(DP_SRC,
                    BKGD_SRC_BKGD_CLR | FRGD_SRC_FRGD_CLR | MONO_SRC_ONE,
                    par);
        aty_st_le32(DST_CNTL,
                    DST_LAST_PEL | DST_Y_TOP_TO_BOTTOM |
                    DST_X_LEFT_TO_RIGHT | rotation, par);
        draw_rect(dx, rect->dy, width, rect->height, par);
}

void atyfb_imageblit(struct fb_info *info, const struct fb_image *image)
{
        struct atyfb_par *par = (struct atyfb_par *) info->par;
        u32 src_bytes, dx = image->dx, dy = image->dy, width = image->width;
        u32 pix_width, rotation = 0, src, mix;

        if (par->asleep)
                return;
        if (!image->width || !image->height)
                return;
        if (!par->accel_flags ||
            (image->depth != 1 && info->var.bits_per_pixel != image->depth)) {
                cfb_imageblit(info, image);
                return;
        }

        pix_width = par->crtc.dp_pix_width;

        switch (image->depth) {
        case 1:
            pix_width &= ~(BYTE_ORDER_MASK | HOST_MASK);
            pix_width |= (BYTE_ORDER_MSB_TO_LSB | HOST_1BPP);
            break;
        case 4:
            pix_width &= ~(BYTE_ORDER_MASK | HOST_MASK);
            pix_width |= (BYTE_ORDER_MSB_TO_LSB | HOST_4BPP);
            break;
        case 8:
            pix_width &= ~HOST_MASK;
            pix_width |= HOST_8BPP;
            break;
        case 15:
            pix_width &= ~HOST_MASK;
            pix_width |= HOST_15BPP;
            break;
        case 16:
            pix_width &= ~HOST_MASK;
            pix_width |= HOST_16BPP;
            break;
        case 24:
            pix_width &= ~HOST_MASK;
            pix_width |= HOST_24BPP;
            break;
        case 32:
            pix_width &= ~HOST_MASK;
            pix_width |= HOST_32BPP;
            break;
        }

        if (info->var.bits_per_pixel == 24) {
                /* In 24 bpp, the engine is in 8 bpp - this requires that all */
                /* horizontal coordinates and widths must be adjusted */
                dx *= 3;
                width *= 3;

                rotation = rotation24bpp(dx, DST_X_LEFT_TO_RIGHT);

                pix_width &= ~DST_MASK;
                pix_width |= DST_8BPP;

                /*
                 * since Rage 3D IIc we have DP_HOST_TRIPLE_EN bit
                 * this hwaccelerated triple has an issue with not aligned data
                 */
                if (image->depth == 1 && M64_HAS(HW_TRIPLE) && image->width % 8 == 0)
                        pix_width |= DP_HOST_TRIPLE_EN;
        }

        if (image->depth == 1) {
                u32 fg, bg;
                if (info->fix.visual == FB_VISUAL_TRUECOLOR ||
                    info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
                        fg = ((u32*)(info->pseudo_palette))[image->fg_color];
                        bg = ((u32*)(info->pseudo_palette))[image->bg_color];
                } else {
                        fg = image->fg_color;
                        bg = image->bg_color;
                }

                wait_for_fifo(2, par);
                aty_st_le32(DP_BKGD_CLR, bg, par);
                aty_st_le32(DP_FRGD_CLR, fg, par);
                src = MONO_SRC_HOST | FRGD_SRC_FRGD_CLR | BKGD_SRC_BKGD_CLR;
                mix = FRGD_MIX_S | BKGD_MIX_S;
        } else {
                src = MONO_SRC_ONE | FRGD_SRC_HOST;
                mix = FRGD_MIX_D_XOR_S | BKGD_MIX_D;
        }

        wait_for_fifo(5, par);
        aty_st_le32(DP_PIX_WIDTH, pix_width, par);
        aty_st_le32(DP_MIX, mix, par);
        aty_st_le32(DP_SRC, src, par);
        aty_st_le32(HOST_CNTL, HOST_BYTE_ALIGN, par);
        aty_st_le32(DST_CNTL, DST_Y_TOP_TO_BOTTOM | DST_X_LEFT_TO_RIGHT | rotation, par);

        draw_rect(dx, dy, width, image->height, par);
        src_bytes = (((image->width * image->depth) + 7) / 8) * image->height;

        /* manual triple each pixel */
        if (image->depth == 1 && info->var.bits_per_pixel == 24 && !(pix_width & DP_HOST_TRIPLE_EN)) {
                int inbit, outbit, mult24, byte_id_in_dword, width;
                u8 *pbitmapin = (u8*)image->data, *pbitmapout;
                u32 hostdword;

                for (width = image->width, inbit = 7, mult24 = 0; src_bytes; ) {
                        for (hostdword = 0, pbitmapout = (u8*)&hostdword, byte_id_in_dword = 0;
                                byte_id_in_dword < 4 && src_bytes;
                                byte_id_in_dword++, pbitmapout++) {
                                for (outbit = 7; outbit >= 0; outbit--) {
                                        *pbitmapout |= (((*pbitmapin >> inbit) & 1) << outbit);
                                        mult24++;
                                        /* next bit */
                                        if (mult24 == 3) {
                                                mult24 = 0;
                                                inbit--;
                                                width--;
                                        }

                                        /* next byte */
                                        if (inbit < 0 || width == 0) {
                                                src_bytes--;
                                                pbitmapin++;
                                                inbit = 7;

                                                if (width == 0) {
                                                    width = image->width;
                                                    outbit = 0;
                                                }
                                        }
                                }
                        }
                        wait_for_fifo(1, par);
                        aty_st_le32(HOST_DATA0, le32_to_cpu(hostdword), par);
                }
        } else {
                u32 *pbitmap, dwords = (src_bytes + 3) / 4;
                for (pbitmap = (u32*)(image->data); dwords; dwords--, pbitmap++) {
                        wait_for_fifo(1, par);
                        aty_st_le32(HOST_DATA0, get_unaligned_le32(pbitmap), par);
                }
        }
}