/*-*- linux-c -*-
 *  linux/drivers/video/i810_accel.c -- Hardware Acceleration
 *
 *      Copyright (C) 2001 Antonino Daplas<adaplas@pol.net>
 *      All Rights Reserved      
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/fb.h>

#include "i810_regs.h"
#include "i810.h"
#include "i810_main.h"

static u32 i810fb_rop[] = {
        COLOR_COPY_ROP, /* ROP_COPY */
        XOR_ROP         /* ROP_XOR  */
};

/* Macros */
#define PUT_RING(n) {                                        \
        i810_writel(par->cur_tail, par->iring.virtual, n);   \
        par->cur_tail += 4;                                  \
        par->cur_tail &= RING_SIZE_MASK;                     \
}                                                                      

extern void flush_cache(void);

/************************************************************/

/* BLT Engine Routines */
static inline void i810_report_error(u8 __iomem *mmio)
{
        printk("IIR     : 0x%04x\n"
               "EIR     : 0x%04x\n"
               "PGTBL_ER: 0x%04x\n"
               "IPEIR   : 0x%04x\n"
               "IPEHR   : 0x%04x\n",
               i810_readw(IIR, mmio),
               i810_readb(EIR, mmio),
               i810_readl(PGTBL_ER, mmio),
               i810_readl(IPEIR, mmio), 
               i810_readl(IPEHR, mmio));
}

/**
 * wait_for_space - check ring buffer free space
 * @space: amount of ringbuffer space needed in bytes
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * The function waits until a free space from the ringbuffer
 * is available 
 */     
static inline int wait_for_space(struct fb_info *info, u32 space)
{
        struct i810fb_par *par = info->par;
        u32 head, count = WAIT_COUNT, tail;
        u8 __iomem *mmio = par->mmio_start_virtual;

        tail = par->cur_tail;
        while (count--) {
                head = i810_readl(IRING + 4, mmio) & RBUFFER_HEAD_MASK; 
                if ((tail == head) || 
                    (tail > head && 
                     (par->iring.size - tail + head) >= space) || 
                    (tail < head && (head - tail) >= space)) {
                        return 0;       
                }
        }
        printk("ringbuffer lockup!!!\n");
        i810_report_error(mmio); 
        par->dev_flags |= LOCKUP;
        info->pixmap.scan_align = 1;
        return 1;
}

/** 
 * wait_for_engine_idle - waits for all hardware engines to finish
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * This waits for lring(0), iring(1), and batch(3), etc to finish and
 * waits until ringbuffer is empty.
 */
static inline int wait_for_engine_idle(struct fb_info *info)
{
        struct i810fb_par *par = info->par;
        u8 __iomem *mmio = par->mmio_start_virtual;
        int count = WAIT_COUNT;

        if (wait_for_space(info, par->iring.size)) /* flush */
                return 1;

        while((i810_readw(INSTDONE, mmio) & 0x7B) != 0x7B && --count); 
        if (count) return 0;

        printk("accel engine lockup!!!\n");
        printk("INSTDONE: 0x%04x\n", i810_readl(INSTDONE, mmio));
        i810_report_error(mmio); 
        par->dev_flags |= LOCKUP;
        info->pixmap.scan_align = 1;
        return 1;
}

/* begin_iring - prepares the ringbuffer 
 * @space: length of sequence in dwords
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * Checks/waits for sufficent space in ringbuffer of size
 * space.  Returns the tail of the buffer
 */ 
static inline u32 begin_iring(struct fb_info *info, u32 space)
{
        struct i810fb_par *par = info->par;

        if (par->dev_flags & ALWAYS_SYNC) 
                wait_for_engine_idle(info);
        return wait_for_space(info, space);
}

/**
 * end_iring - advances the buffer
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * This advances the tail of the ringbuffer, effectively
 * beginning the execution of the graphics instruction sequence.
 */
static inline void end_iring(struct i810fb_par *par)
{
        u8 __iomem *mmio = par->mmio_start_virtual;

        i810_writel(IRING, mmio, par->cur_tail);
}

/**
 * source_copy_blit - BLIT transfer operation
 * @dwidth: width of rectangular graphics data
 * @dheight: height of rectangular graphics data
 * @dpitch: bytes per line of destination buffer
 * @xdir: direction of copy (left to right or right to left)
 * @src: address of first pixel to read from
 * @dest: address of first pixel to write to
 * @from: source address
 * @where: destination address
 * @rop: raster operation
 * @blit_bpp: pixel format which can be different from the 
 *            framebuffer's pixelformat
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * This is a BLIT operation typically used when doing
 * a 'Copy and Paste'
 */
static inline void source_copy_blit(int dwidth, int dheight, int dpitch, 
                                    int xdir, int src, int dest, int rop, 
                                    int blit_bpp, struct fb_info *info)
{
        struct i810fb_par *par = info->par;

        if (begin_iring(info, 24 + IRING_PAD)) return;

        PUT_RING(BLIT | SOURCE_COPY_BLIT | 4);
        PUT_RING(xdir | rop << 16 | dpitch | DYN_COLOR_EN | blit_bpp);
        PUT_RING(dheight << 16 | dwidth);
        PUT_RING(dest);
        PUT_RING(dpitch);
        PUT_RING(src);

        end_iring(par);
}       

/**
 * color_blit - solid color BLIT operation
 * @width: width of destination
 * @height: height of destination
 * @pitch: pixels per line of the buffer
 * @dest: address of first pixel to write to
 * @where: destination
 * @rop: raster operation
 * @what: color to transfer
 * @blit_bpp: pixel format which can be different from the 
 *            framebuffer's pixelformat
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * A BLIT operation which can be used for  color fill/rectangular fill
 */
static inline void color_blit(int width, int height, int pitch,  int dest, 
                              int rop, int what, int blit_bpp, 
                              struct fb_info *info)
{
        struct i810fb_par *par = info->par;

        if (begin_iring(info, 24 + IRING_PAD)) return;

        PUT_RING(BLIT | COLOR_BLT | 3);
        PUT_RING(rop << 16 | pitch | SOLIDPATTERN | DYN_COLOR_EN | blit_bpp);
        PUT_RING(height << 16 | width);
        PUT_RING(dest);
        PUT_RING(what);
        PUT_RING(NOP);

        end_iring(par);
}
 
/**
 * mono_src_copy_imm_blit - color expand from system memory to framebuffer
 * @dwidth: width of destination
 * @dheight: height of destination
 * @dpitch: pixels per line of the buffer
 * @dsize: size of bitmap in double words
 * @dest: address of first byte of pixel;
 * @rop: raster operation
 * @blit_bpp: pixelformat to use which can be different from the 
 *            framebuffer's pixelformat
 * @src: address of image data
 * @bg: backgound color
 * @fg: forground color
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * A color expand operation where the  source data is placed in the 
 * ringbuffer itself. Useful for drawing text. 
 *
 * REQUIREMENT:
 * The end of a scanline must be padded to the next word.
 */
static inline void mono_src_copy_imm_blit(int dwidth, int dheight, int dpitch,
                                          int dsize, int blit_bpp, int rop,
                                          int dest, const u32 *src, int bg,
                                          int fg, struct fb_info *info)
{
        struct i810fb_par *par = info->par;

        if (begin_iring(info, 24 + (dsize << 2) + IRING_PAD)) return;

        PUT_RING(BLIT | MONO_SOURCE_COPY_IMMEDIATE | (4 + dsize));
        PUT_RING(DYN_COLOR_EN | blit_bpp | rop << 16 | dpitch);
        PUT_RING(dheight << 16 | dwidth);
        PUT_RING(dest);
        PUT_RING(bg);
        PUT_RING(fg);
        while (dsize--) 
                PUT_RING(*src++);

        end_iring(par);
}

static inline void load_front(int offset, struct fb_info *info)
{
        struct i810fb_par *par = info->par;

        if (begin_iring(info, 8 + IRING_PAD)) return;

        PUT_RING(PARSER | FLUSH);
        PUT_RING(NOP);

        end_iring(par);

        if (begin_iring(info, 8 + IRING_PAD)) return;

        PUT_RING(PARSER | FRONT_BUFFER | ((par->pitch >> 3) << 8));
        PUT_RING((par->fb.offset << 12) + offset);

        end_iring(par);
}

/**
 * i810fb_iring_enable - enables/disables the ringbuffer
 * @mode: enable or disable
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * Enables or disables the ringbuffer, effectively enabling or
 * disabling the instruction/acceleration engine.
 */
static inline void i810fb_iring_enable(struct i810fb_par *par, u32 mode)
{
        u32 tmp;
        u8 __iomem *mmio = par->mmio_start_virtual;

        tmp = i810_readl(IRING + 12, mmio);
        if (mode == OFF) 
                tmp &= ~1;
        else 
                tmp |= 1;
        flush_cache();
        i810_writel(IRING + 12, mmio, tmp);
}       

void i810fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
        struct i810fb_par *par = info->par;
        u32 dx, dy, width, height, dest, rop = 0, color = 0;

        if (!info->var.accel_flags || par->dev_flags & LOCKUP ||
            par->depth == 4) {
                cfb_fillrect(info, rect);
                return;
        }

        if (par->depth == 1) 
                color = rect->color;
        else 
                color = ((u32 *) (info->pseudo_palette))[rect->color];

        rop = i810fb_rop[rect->rop];

        dx = rect->dx * par->depth;
        width = rect->width * par->depth;
        dy = rect->dy;
        height = rect->height;

        dest = info->fix.smem_start + (dy * info->fix.line_length) + dx;
        color_blit(width, height, info->fix.line_length, dest, rop, color, 
                   par->blit_bpp, info);
}
        
void i810fb_copyarea(struct fb_info *info, const struct fb_copyarea *region) 
{
        struct i810fb_par *par = info->par;
        u32 sx, sy, dx, dy, pitch, width, height, src, dest, xdir;

        if (!info->var.accel_flags || par->dev_flags & LOCKUP ||
            par->depth == 4) {
                cfb_copyarea(info, region);
                return;
        }

        dx = region->dx * par->depth;
        sx = region->sx * par->depth;
        width = region->width * par->depth;
        sy = region->sy;
        dy = region->dy;
        height = region->height;

        if (dx <= sx) {
                xdir = INCREMENT;
        }
        else {
                xdir = DECREMENT;
                sx += width - 1;
                dx += width - 1;
        }
        if (dy <= sy) {
                pitch = info->fix.line_length;
        }
        else {
                pitch = (-(info->fix.line_length)) & 0xFFFF;
                sy += height - 1;
                dy += height - 1;
        }
        src = info->fix.smem_start + (sy * info->fix.line_length) + sx;
        dest = info->fix.smem_start + (dy * info->fix.line_length) + dx;

        source_copy_blit(width, height, pitch, xdir, src, dest,
                         PAT_COPY_ROP, par->blit_bpp, info);
}

void i810fb_imageblit(struct fb_info *info, const struct fb_image *image)
{
        struct i810fb_par *par = info->par;
        u32 fg = 0, bg = 0, size, dst;
        
        if (!info->var.accel_flags || par->dev_flags & LOCKUP ||
            par->depth == 4 || image->depth != 1) {
                cfb_imageblit(info, image);
                return;
        }

        switch (info->var.bits_per_pixel) {
        case 8:
                fg = image->fg_color;
                bg = image->bg_color;
                break;
        case 16:
        case 24:
                fg = ((u32 *)(info->pseudo_palette))[image->fg_color];
                bg = ((u32 *)(info->pseudo_palette))[image->bg_color];
                break;
        }       
        
        dst = info->fix.smem_start + (image->dy * info->fix.line_length) + 
                (image->dx * par->depth);

        size = (image->width+7)/8 + 1;
        size &= ~1;
        size *= image->height;
        size += 7;
        size &= ~7;
        mono_src_copy_imm_blit(image->width * par->depth, 
                               image->height, info->fix.line_length, 
                               size/4, par->blit_bpp,
                               PAT_COPY_ROP, dst, (u32 *) image->data, 
                               bg, fg, info);
} 

int i810fb_sync(struct fb_info *info)
{
        struct i810fb_par *par = info->par;
        
        if (!info->var.accel_flags || par->dev_flags & LOCKUP)
                return 0;

        return wait_for_engine_idle(info);
}

void i810fb_load_front(u32 offset, struct fb_info *info)
{
        struct i810fb_par *par = info->par;
        u8 __iomem *mmio = par->mmio_start_virtual;

        if (!info->var.accel_flags || par->dev_flags & LOCKUP)
                i810_writel(DPLYBASE, mmio, par->fb.physical + offset);
        else 
                load_front(offset, info);
}

/**
 * i810fb_init_ringbuffer - initialize the ringbuffer
 * @par: pointer to i810fb_par structure
 *
 * DESCRIPTION:
 * Initializes the ringbuffer by telling the device the
 * size and location of the ringbuffer.  It also sets 
 * the head and tail pointers = 0
 */
void i810fb_init_ringbuffer(struct fb_info *info)
{
        struct i810fb_par *par = info->par;
        u32 tmp1, tmp2;
        u8 __iomem *mmio = par->mmio_start_virtual;
        
        wait_for_engine_idle(info);
        i810fb_iring_enable(par, OFF);
        i810_writel(IRING, mmio, 0);
        i810_writel(IRING + 4, mmio, 0);
        par->cur_tail = 0;

        tmp2 = i810_readl(IRING + 8, mmio) & ~RBUFFER_START_MASK; 
        tmp1 = par->iring.physical;
        i810_writel(IRING + 8, mmio, tmp2 | tmp1);

        tmp1 = i810_readl(IRING + 12, mmio);
        tmp1 &= ~RBUFFER_SIZE_MASK;
        tmp2 = (par->iring.size - I810_PAGESIZE) & RBUFFER_SIZE_MASK;
        i810_writel(IRING + 12, mmio, tmp1 | tmp2);
        i810fb_iring_enable(par, ON);
}