LXR linux/arch/powerpc/boot/pq2.c

   1/*
   2 * PowerQUICC II support functions
   3 *
   4 * Author: Scott Wood <scottwood@freescale.com>
   5 *
   6 * Copyright (c) 2007 Freescale Semiconductor, Inc.
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License version 2 as published
  10 * by the Free Software Foundation.
  11 */
  12
  13#include "ops.h"
  14#include "types.h"
  15#include "fsl-soc.h"
  16#include "pq2.h"
  17#include "stdio.h"
  18#include "io.h"
  19
  20#define PQ2_SCCR (0x10c80/4) /* System Clock Configuration Register */
  21#define PQ2_SCMR (0x10c88/4) /* System Clock Mode Register */
  22
  23static int pq2_corecnf_map[] = {
  24        3, 2, 2, 2, 4, 4, 5, 9, 6, 11, 8, 10, 3, 12, 7, -1,
  25        6, 5, 13, 2, 14, 4, 15, 9, 0, 11, 8, 10, 16, 12, 7, -1
  26};
  27
  28/* Get various clocks from crystal frequency.
  29 * Returns zero on failure and non-zero on success.
  30 */
  31int pq2_get_clocks(u32 crystal, u32 *sysfreq, u32 *corefreq,
  32                   u32 *timebase, u32 *brgfreq)
  33{
  34        u32 *immr;
  35        u32 sccr, scmr, mainclk, busclk;
  36        int corecnf, busdf, plldf, pllmf, dfbrg;
  37
  38        immr = fsl_get_immr();
  39        if (!immr) {
  40                printf("pq2_get_clocks: Couldn't get IMMR base.\r\n");
  41                return 0;
  42        }
  43
  44        sccr = in_be32(&immr[PQ2_SCCR]);
  45        scmr = in_be32(&immr[PQ2_SCMR]);
  46
  47        dfbrg = sccr & 3;
  48        corecnf = (scmr >> 24) & 0x1f;
  49        busdf = (scmr >> 20) & 0xf;
  50        plldf = (scmr >> 12) & 1;
  51        pllmf = scmr & 0xfff;
  52
  53        mainclk = crystal * (pllmf + 1) / (plldf + 1);
  54        busclk = mainclk / (busdf + 1);
  55
  56        if (sysfreq)
  57                *sysfreq = mainclk / 2;
  58        if (timebase)
  59                *timebase = busclk / 4;
  60        if (brgfreq)
  61                *brgfreq = mainclk / (1 << ((dfbrg + 1) * 2));
  62
  63        if (corefreq) {
  64                int coremult = pq2_corecnf_map[corecnf];
  65
  66                if (coremult < 0)
  67                        *corefreq = mainclk / 2;
  68                else if (coremult == 0)
  69                        return 0;
  70                else
  71                        *corefreq = busclk * coremult / 2;
  72        }
  73
  74        return 1;
  75}
  76
  77/* Set common device tree fields based on the given clock frequencies. */
  78void pq2_set_clocks(u32 sysfreq, u32 corefreq, u32 timebase, u32 brgfreq)
  79{
  80        void *node;
  81
  82        dt_fixup_cpu_clocks(corefreq, timebase, sysfreq);
  83
  84        node = finddevice("/soc/cpm");
  85        if (node)
  86                setprop(node, "clock-frequency", &sysfreq, 4);
  87
  88        node = finddevice("/soc/cpm/brg");
  89        if (node)
  90                setprop(node, "clock-frequency", &brgfreq, 4);
  91}
  92
  93int pq2_fixup_clocks(u32 crystal)
  94{
  95        u32 sysfreq, corefreq, timebase, brgfreq;
  96
  97        if (!pq2_get_clocks(crystal, &sysfreq, &corefreq, &timebase, &brgfreq))
  98                return 0;
  99
 100        pq2_set_clocks(sysfreq, corefreq, timebase, brgfreq);
 101        return 1;
 102}
 103