Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * MPC8xx support functions

 *

 * Author: Scott Wood <scottwood@freescale.com>

 *

 * Copyright (c) 2007 Freescale Semiconductor, Inc.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published

 * by the Free Software Foundation.

 */

#include "ops.h"

#include "types.h"

#include "fsl-soc.h"

#include "mpc8xx.h"

#include "stdio.h"

#include "io.h"

#define MPC8XX_PLPRCR (0x284/4) /* PLL and Reset Control Register */

/* Return system clock from crystal frequency */

u32 mpc885_get_clock(u32 crystal)

{

        u32 *immr;

        u32 plprcr;

        int mfi, mfn, mfd, pdf, div;

        u32 ret;

        immr = fsl_get_immr();

        if (!immr) {

                printf("mpc885_get_clock: Couldn't get IMMR base.\r\n");

                return 0;

        }

        plprcr = in_be32(&immr[MPC8XX_PLPRCR]);

        mfi = (plprcr >> 16) & 15;

        if (mfi < 5) {

                printf("Warning: PLPRCR[MFI] value of %d out-of-bounds\r\n",

                       mfi);

                mfi = 5;

        }

        pdf = (plprcr >> 1) & 0xf;

        div = (plprcr >> 20) & 3;

        mfd = (plprcr >> 22) & 0x1f;

        mfn = (plprcr >> 27) & 0x1f;

        ret = crystal * mfi;

        if (mfn != 0)

                ret += crystal * mfn / (mfd + 1);

        return ret / (pdf + 1);

}

/* Set common device tree fields based on the given clock frequencies. */

void mpc8xx_set_clocks(u32 sysclk)

{

        void *node;

        dt_fixup_cpu_clocks(sysclk, sysclk / 16, sysclk);

        node = finddevice("/soc/cpm");

        if (node)

                setprop(node, "clock-frequency", &sysclk, 4);

        node = finddevice("/soc/cpm/brg");

        if (node)

                setprop(node, "clock-frequency", &sysclk, 4);

}

int mpc885_fixup_clocks(u32 crystal)

{

        u32 sysclk = mpc885_get_clock(crystal);

        if (!sysclk)

                return 0;

        mpc8xx_set_clocks(sysclk);

        return 1;

}