pq2.c

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/*
 * PowerQUICC II support functions
 *
 * Author: Scott Wood <[email protected]>
 *
 * 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 "pq2.h"
#include "stdio.h"
#include "io.h"

#define PQ2_SCCR (0x10c80/4) /* System Clock Configuration Register */
#define PQ2_SCMR (0x10c88/4) /* System Clock Mode Register */

static int pq2_corecnf_map[] = {
    3, 2, 2, 2, 4, 4, 5, 9, 6, 11, 8, 10, 3, 12, 7, -1,
    6, 5, 13, 2, 14, 4, 15, 9, 0, 11, 8, 10, 16, 12, 7, -1
};

/* Get various clocks from crystal frequency.
 * Returns zero on failure and non-zero on success.
 */
int pq2_get_clocks(u32 crystal, u32 *sysfreq, u32 *corefreq,
                   u32 *timebase, u32 *brgfreq)
{
    u32 *immr;
    u32 sccr, scmr, mainclk, busclk;
    int corecnf, busdf, plldf, pllmf, dfbrg;

    immr = fsl_get_immr();
    if (!immr) {
        printf("pq2_get_clocks: Couldn't get IMMR base.\r\n");
        return 0;
    }

    sccr = in_be32(&immr[PQ2_SCCR]);
    scmr = in_be32(&immr[PQ2_SCMR]);

    dfbrg = sccr & 3;
    corecnf = (scmr >> 24) & 0x1f;
    busdf = (scmr >> 20) & 0xf;
    plldf = (scmr >> 12) & 1;
    pllmf = scmr & 0xfff;

    mainclk = crystal * (pllmf + 1) / (plldf + 1);
    busclk = mainclk / (busdf + 1);

    if (sysfreq)
        *sysfreq = mainclk / 2;
    if (timebase)
        *timebase = busclk / 4;
    if (brgfreq)
        *brgfreq = mainclk / (1 << ((dfbrg + 1) * 2));

    if (corefreq) {
        int coremult = pq2_corecnf_map[corecnf];

        if (coremult < 0)
            *corefreq = mainclk / 2;
        else if (coremult == 0)
            return 0;
        else
            *corefreq = busclk * coremult / 2;
    }

    return 1;
}

/* Set common device tree fields based on the given clock frequencies. */
void pq2_set_clocks(u32 sysfreq, u32 corefreq, u32 timebase, u32 brgfreq)
{
    void *node;

    dt_fixup_cpu_clocks(corefreq, timebase, sysfreq);

    node = finddevice("/soc/cpm");
    if (node)
        setprop(node, "clock-frequency", &sysfreq, 4);

    node = finddevice("/soc/cpm/brg");
    if (node)
        setprop(node, "clock-frequency", &brgfreq, 4);
}

int pq2_fixup_clocks(u32 crystal)
{
    u32 sysfreq, corefreq, timebase, brgfreq;

    if (!pq2_get_clocks(crystal, &sysfreq, &corefreq, &timebase, &brgfreq))
        return 0;

    pq2_set_clocks(sysfreq, corefreq, timebase, brgfreq);
    return 1;
}