static struct s3c2410fb_display tq2440_lcd_cfg __initdata = {

    .lcdcon5    = S3C2410_LCDCON5_FRM565 |

              S3C2410_LCDCON5_INVVLINE |

              S3C2410_LCDCON5_INVVFRAME |

              S3C2410_LCDCON5_PWREN |

              S3C2410_LCDCON5_HWSWP,

    .type        = S3C2410_LCDCON1_TFT,

    .width        = 480,

    .height        = 272,

    .pixclock    = 100000,

    .xres        = 480,

    .yres        = 272,

    .bpp        = 16,

    .left_margin    = 2,   /* For HBPD+1， 这里我们取的都是典型值  */

    .right_margin    = 2,  /* For HFPD+1  */

    .hsync_len    = 41,    /* For HSPW+1  */

    .upper_margin    = 2,  /* For VBPD+1  */

    .lower_margin    = 2,  /* For VFPD+1  */

    .vsync_len    = 10,    /* For VSPW+1  */

};

#define S3C2410_GPCCON_MASK(x)    (3 << ((x) * 2))

#define S3C2410_GPDCON_MASK(x)    (3 << ((x) * 2))

static struct s3c2410fb_mach_info tq2440_fb_info __initdata = {

    .displays    = &tq2440_lcd_cfg,

    .num_displays    = 1,

    .default_display = 0,

    /* Enable VD[2..7], VD[10..15], VD[18..23] and VCLK, syncs, VDEN

     * and disable the pull down resistors on pins we are using for LCD

     * data. */

    .gpcup        = (0xf << 1) | (0x3f << 10),

    .gpccon        = (S3C2410_GPC1_VCLK   | S3C2410_GPC2_VLINE |

               S3C2410_GPC3_VFRAME | S3C2410_GPC4_VM |

               S3C2410_GPC8_VD0   | S3C2410_GPC9_VD1 |

               S3C2410_GPC10_VD2   | S3C2410_GPC11_VD3 |

               S3C2410_GPC12_VD4   | S3C2410_GPC13_VD5 |

               S3C2410_GPC14_VD6   | S3C2410_GPC15_VD7),

    .gpccon_mask    = (S3C2410_GPCCON_MASK(1)  | S3C2410_GPCCON_MASK(2)  |

               S3C2410_GPCCON_MASK(3)  | S3C2410_GPCCON_MASK(4)  |

               S3C2410_GPCCON_MASK(8) | S3C2410_GPCCON_MASK(9) |

               S3C2410_GPCCON_MASK(10) | S3C2410_GPCCON_MASK(11) |

               S3C2410_GPCCON_MASK(12) | S3C2410_GPCCON_MASK(13) |

               S3C2410_GPCCON_MASK(14) | S3C2410_GPCCON_MASK(15)),

    .gpdup        = (0x3f << 2) | (0x3f << 10),

    .gpdcon        = (S3C2410_GPD2_VD10  | S3C2410_GPD3_VD11 |

               S3C2410_GPD4_VD12  | S3C2410_GPD5_VD13 |

               S3C2410_GPD6_VD14  | S3C2410_GPD7_VD15 |

               S3C2410_GPD10_VD18 | S3C2410_GPD11_VD19 |

               S3C2410_GPD12_VD20 | S3C2410_GPD13_VD21 |

               S3C2410_GPD14_VD22 | S3C2410_GPD15_VD23),

    .gpdcon_mask    = (S3C2410_GPDCON_MASK(2)  | S3C2410_GPDCON_MASK(3) |

               S3C2410_GPDCON_MASK(4)  | S3C2410_GPDCON_MASK(5) |

               S3C2410_GPDCON_MASK(6)  | S3C2410_GPDCON_MASK(7) |

               S3C2410_GPDCON_MASK(10) | S3C2410_GPDCON_MASK(11)|

               S3C2410_GPDCON_MASK(12) | S3C2410_GPDCON_MASK(13)|

               S3C2410_GPDCON_MASK(14) | S3C2410_GPDCON_MASK(15)),

//    .lpcsel        = ((0xCE6) & ~7) | 1<<4,  // 禁用lpsel，因为如果不是使用三星LPC3600/LCC3600 LCD，必须禁止LPC3600/LCC3600模式(写入0到TCONSEL)。

};

static void s3c2410fb_activate_var(struct fb_info *info)

{

    struct s3c2410fb_info *fbi = info->par;

    void __iomem *regs = fbi->io;

    int type = fbi->regs.lcdcon1 & S3C2410_LCDCON1_TFT;

    struct fb_var_screeninfo *var = &info->var;

    int clkdiv;

    clkdiv = DIV_ROUND_UP(s3c2410fb_calc_pixclk(fbi, var->pixclock), 2);

    dprintk("%s: var->xres  = %d\n", __func__, var->xres);

    dprintk("%s: var->yres  = %d\n", __func__, var->yres);

    dprintk("%s: var->bpp   = %d\n", __func__, var->bits_per_pixel);

    if (type == S3C2410_LCDCON1_TFT) {

        s3c2410fb_calculate_tft_lcd_regs(info, &fbi->regs);

        --clkdiv;

        if (clkdiv < 0)

            clkdiv = 0;

    } else {

        s3c2410fb_calculate_stn_lcd_regs(info, &fbi->regs);

        if (clkdiv < 2)

            clkdiv = 2;

    }

    fbi->regs.lcdcon1 |=  S3C2410_LCDCON1_CLKVAL(clkdiv);

     ......

}

static unsigned int s3c2410fb_calc_pixclk(struct s3c2410fb_info *fbi,

                      unsigned long pixclk)

{

    unsigned long clk = fbi->clk_rate;

    unsigned long long div;

    /* pixclk is in picoseconds, our clock is in Hz

     *

     * Hz -> picoseconds is / 10^-12

     */

    div = (unsigned long long)clk * pixclk;

    div >>= 12;            /* div / 2^12 */

    do_div(div, 625 * 625UL * 625); /* div / 5^12 */

    dprintk("pixclk %ld, divisor is %ld\n", pixclk, (long)div);

    return div;

}