/*
 *  ATI Mach64 CT/VT/GT/LT Support
 */

#include <linux/fb.h>

#include <asm/io.h>

#include <video/fbcon.h>

#include "mach64.h"
#include "atyfb.h"


/* FIXME: remove the FAIL definition */
#define FAIL(x) do { printk(x "\n"); return -EINVAL; } while (0)

static void aty_st_pll(int offset, u8 val, const struct fb_info_aty *info);

static int aty_valid_pll_ct(const struct fb_info_aty *info, u32 vclk_per,
			    struct pll_ct *pll);
static int aty_dsp_gt(const struct fb_info_aty *info, u8 bpp,
		      struct pll_ct *pll);
static int aty_var_to_pll_ct(const struct fb_info_aty *info, u32 vclk_per,
			     u8 bpp, union aty_pll *pll);
static u32 aty_pll_ct_to_var(const struct fb_info_aty *info,
			     const union aty_pll *pll);



static void aty_st_pll(int offset, u8 val, const struct fb_info_aty *info)
{
    /* write addr byte */
    aty_st_8(CLOCK_CNTL + 1, (offset << 2) | PLL_WR_EN, info);
    /* write the register value */
    aty_st_8(CLOCK_CNTL + 2, val, info);
    aty_st_8(CLOCK_CNTL + 1, (offset << 2) & ~PLL_WR_EN, info);
}


/* ------------------------------------------------------------------------- */

    /*
     *  PLL programming (Mach64 CT family)
     */

static int aty_dsp_gt(const struct fb_info_aty *info, u8 bpp,
		      struct pll_ct *pll)
{
    u32 dsp_xclks_per_row, dsp_loop_latency, dsp_precision, dsp_off, dsp_on;
    u32 xclks_per_row, fifo_off, fifo_on, y, fifo_size, page_size;

    /* xclocks_per_row<<11 */
    xclks_per_row = (pll->mclk_fb_div*pll->vclk_post_div_real*64<<11)/
		    (pll->vclk_fb_div*pll->mclk_post_div_real*bpp);
    if (xclks_per_row < (1<<11))
	FAIL("Dotclock to high");
    if (M64_HAS(FIFO_24)) {
	fifo_size = 24;
	dsp_loop_latency = 0;
    } else {
	fifo_size = 32;
	dsp_loop_latency = 2;
    }
    dsp_precision = 0;
    y = (xclks_per_row*fifo_size)>>11;
    while (y) {
	y >>= 1;
	dsp_precision++;
    }
    dsp_precision -= 5;
    /* fifo_off<<6 */
    fifo_off = ((xclks_per_row*(fifo_size-1))>>5)+(3<<6);

    if (info->total_vram > 1*1024*1024) {
	if (info->ram_type >= SDRAM) {
	    /* >1 MB SDRAM */
	    dsp_loop_latency += 8;
	    page_size = 8;
	} else {
	    /* >1 MB DRAM */
	    dsp_loop_latency += 6;
	    page_size = 9;
	}
    } else {
	if (info->ram_type >= SDRAM) {
	    /* <2 MB SDRAM */
	    dsp_loop_latency += 9;
	    page_size = 10;
	} else {
	    /* <2 MB DRAM */
	    dsp_loop_latency += 8;
	    page_size = 10;
	}
    }
    /* fifo_on<<6 */
    if (xclks_per_row >= (page_size<<11))
	fifo_on = ((2*page_size+1)<<6)+(xclks_per_row>>5);
    else
	fifo_on = (3*page_size+2)<<6;

    dsp_xclks_per_row = xclks_per_row>>dsp_precision;
    dsp_on = fifo_on>>dsp_precision;
    dsp_off = fifo_off>>dsp_precision;

    pll->dsp_config = (dsp_xclks_per_row & 0x3fff) |
		      ((dsp_loop_latency & 0xf)<<16) |
		      ((dsp_precision & 7)<<20);
    pll->dsp_on_off = (dsp_on & 0x7ff) | ((dsp_off & 0x7ff)<<16);
    return 0;
}

static int aty_valid_pll_ct(const struct fb_info_aty *info, u32 vclk_per,
			    struct pll_ct *pll)
{
    u32 q, x;			/* x is a workaround for sparc64-linux-gcc */
    x = x;			/* x is a workaround for sparc64-linux-gcc */

    pll->pll_ref_div = info->pll_per*2*255/info->ref_clk_per;

    /* FIXME: use the VTB/GTB /3 post divider if it's better suited */
    q = info->ref_clk_per*pll->pll_ref_div*4/info->mclk_per;	/* actually 8*q */
    if (q < 16*8 || q > 255*8)
	FAIL("mclk out of range");
    else if (q < 32*8)
	pll->mclk_post_div_real = 8;
    else if (q < 64*8)
	pll->mclk_post_div_real = 4;
    else if (q < 128*8)
	pll->mclk_post_div_real = 2;
    else
	pll->mclk_post_div_real = 1;
    pll->mclk_fb_div = q*pll->mclk_post_div_real/8;

    /* FIXME: use the VTB/GTB /{3,6,12} post dividers if they're better suited */
    q = info->ref_clk_per*pll->pll_ref_div*4/vclk_per;	/* actually 8*q */
    if (q < 16*8 || q > 255*8)
	FAIL("vclk out of range");
    else if (q < 32*8)
	pll->vclk_post_div_real = 8;
    else if (q < 64*8)
	pll->vclk_post_div_real = 4;
    else if (q < 128*8)
	pll->vclk_post_div_real = 2;
    else
	pll->vclk_post_div_real = 1;
    pll->vclk_fb_div = q*pll->vclk_post_div_real/8;
    return 0;
}

void aty_calc_pll_ct(const struct fb_info_aty *info, struct pll_ct *pll)
{
    u8 mpostdiv = 0;
    u8 vpostdiv = 0;

    if (M64_HAS(SDRAM_MAGIC_PLL) && (info->ram_type >= SDRAM))
	pll->pll_gen_cntl = 0x04;
    else
	pll->pll_gen_cntl = 0x84;

    switch (pll->mclk_post_div_real) {
	case 1:
	    mpostdiv = 0;
	    break;
	case 2:
	    mpostdiv = 1;
	    break;
	case 3:
	    mpostdiv = 4;
	    break;
	case 4:
	    mpostdiv = 2;
	    break;
	case 8:
	    mpostdiv = 3;
	    break;
    }
    pll->pll_gen_cntl |= mpostdiv<<4;	/* mclk */

    if (M64_HAS(MAGIC_POSTDIV))
	pll->pll_ext_cntl = 0;
    else
    	pll->pll_ext_cntl = mpostdiv;	/* xclk == mclk */

    switch (pll->vclk_post_div_real) {
	case 2:
	    vpostdiv = 1;
	    break;
	case 3:
	    pll->pll_ext_cntl |= 0x10;
	case 1:
	    vpostdiv = 0;
	    break;
	case 6:
	    pll->pll_ext_cntl |= 0x10;
	case 4:
	    vpostdiv = 2;
	    break;
	case 12:
	    pll->pll_ext_cntl |= 0x10;
	case 8:
	    vpostdiv = 3;
	    break;
    }

    pll->pll_vclk_cntl = 0x03;	/* VCLK = PLL_VCLK/VCLKx_POST */
    pll->vclk_post_div = vpostdiv;
}

static int aty_var_to_pll_ct(const struct fb_info_aty *info, u32 vclk_per,
			     u8 bpp, union aty_pll *pll)
{
    int err;

    if ((err = aty_valid_pll_ct(info, vclk_per, &pll->ct)))
	return err;
    if (M64_HAS(GTB_DSP) && (err = aty_dsp_gt(info, bpp, &pll->ct)))
	return err;
    aty_calc_pll_ct(info, &pll->ct);
    return 0;
}

static u32 aty_pll_ct_to_var(const struct fb_info_aty *info,
			     const union aty_pll *pll)
{
    u32 ref_clk_per = info->ref_clk_per;
    u8 pll_ref_div = pll->ct.pll_ref_div;
    u8 vclk_fb_div = pll->ct.vclk_fb_div;
    u8 vclk_post_div = pll->ct.vclk_post_div_real;

    return ref_clk_per*pll_ref_div*vclk_post_div/vclk_fb_div/2;
}

void aty_set_pll_ct(const struct fb_info_aty *info, const union aty_pll *pll)
{
    aty_st_pll(PLL_REF_DIV, pll->ct.pll_ref_div, info);
    aty_st_pll(PLL_GEN_CNTL, pll->ct.pll_gen_cntl, info);
    aty_st_pll(MCLK_FB_DIV, pll->ct.mclk_fb_div, info);
    aty_st_pll(PLL_VCLK_CNTL, pll->ct.pll_vclk_cntl, info);
    aty_st_pll(VCLK_POST_DIV, pll->ct.vclk_post_div, info);
    aty_st_pll(VCLK0_FB_DIV, pll->ct.vclk_fb_div, info);
    aty_st_pll(PLL_EXT_CNTL, pll->ct.pll_ext_cntl, info);

    if (M64_HAS(GTB_DSP)) {
	if (M64_HAS(XL_DLL))
	    aty_st_pll(DLL_CNTL, 0x80, info);
	else if (info->ram_type >= SDRAM)
	    aty_st_pll(DLL_CNTL, 0xa6, info);
	else
	    aty_st_pll(DLL_CNTL, 0xa0, info);
	aty_st_pll(VFC_CNTL, 0x1b, info);
	aty_st_le32(DSP_CONFIG, pll->ct.dsp_config, info);
	aty_st_le32(DSP_ON_OFF, pll->ct.dsp_on_off, info);
    }
}

static int dummy(void)
{
    return 0;
}

const struct aty_dac_ops aty_dac_ct = {
    set_dac:	(void *)dummy,
};

const struct aty_pll_ops aty_pll_ct = {
    var_to_pll:	aty_var_to_pll_ct,
    pll_to_var:	aty_pll_ct_to_var,
    set_pll:	aty_set_pll_ct,
};