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

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * PowerQUICC II support functions
   4 *
   5 * Author: Scott Wood <scottwood@freescale.com>
   6 *
   7 * Copyright (c) 2007 Freescale Semiconductor, Inc.
   8 */
   9
  10#include "ops.h"
  11#include "types.h"
  12#include "fsl-soc.h"
  13#include "pq2.h"
  14#include "stdio.h"
  15#include "io.h"
  16
  17#define PQ2_SCCR (0x10c80/4) /* System Clock Configuration Register */
  18#define PQ2_SCMR (0x10c88/4) /* System Clock Mode Register */
  19
  20static int pq2_corecnf_map[] = {
  21        3, 2, 2, 2, 4, 4, 5, 9, 6, 11, 8, 10, 3, 12, 7, -1,
  22        6, 5, 13, 2, 14, 4, 15, 9, 0, 11, 8, 10, 16, 12, 7, -1
  23};
  24
  25/* Get various clocks from crystal frequency.
  26 * Returns zero on failure and non-zero on success.
  27 */
  28int pq2_get_clocks(u32 crystal, u32 *sysfreq, u32 *corefreq,
  29                   u32 *timebase, u32 *brgfreq)
  30{
  31        u32 *immr;
  32        u32 sccr, scmr, mainclk, busclk;
  33        int corecnf, busdf, plldf, pllmf, dfbrg;
  34
  35        immr = fsl_get_immr();
  36        if (!immr) {
  37                printf("pq2_get_clocks: Couldn't get IMMR base.\r\n");
  38                return 0;
  39        }
  40
  41        sccr = in_be32(&immr[PQ2_SCCR]);
  42        scmr = in_be32(&immr[PQ2_SCMR]);
  43
  44        dfbrg = sccr & 3;
  45        corecnf = (scmr >> 24) & 0x1f;
  46        busdf = (scmr >> 20) & 0xf;
  47        plldf = (scmr >> 12) & 1;
  48        pllmf = scmr & 0xfff;
  49
  50        mainclk = crystal * (pllmf + 1) / (plldf + 1);
  51        busclk = mainclk / (busdf + 1);
  52
  53        if (sysfreq)
  54                *sysfreq = mainclk / 2;
  55        if (timebase)
  56                *timebase = busclk / 4;
  57        if (brgfreq)
  58                *brgfreq = mainclk / (1 << ((dfbrg + 1) * 2));
  59
  60        if (corefreq) {
  61                int coremult = pq2_corecnf_map[corecnf];
  62
  63                if (coremult < 0)
  64                        *corefreq = mainclk / 2;
  65                else if (coremult == 0)
  66                        return 0;
  67                else
  68                        *corefreq = busclk * coremult / 2;
  69        }
  70
  71        return 1;
  72}
  73
  74/* Set common device tree fields based on the given clock frequencies. */
  75void pq2_set_clocks(u32 sysfreq, u32 corefreq, u32 timebase, u32 brgfreq)
  76{
  77        void *node;
  78
  79        dt_fixup_cpu_clocks(corefreq, timebase, sysfreq);
  80
  81        node = finddevice("/soc/cpm");
  82        if (node)
  83                setprop(node, "clock-frequency", &sysfreq, 4);
  84
  85        node = finddevice("/soc/cpm/brg");
  86        if (node)
  87                setprop(node, "clock-frequency", &brgfreq, 4);
  88}
  89
  90int pq2_fixup_clocks(u32 crystal)
  91{
  92        u32 sysfreq, corefreq, timebase, brgfreq;
  93
  94        if (!pq2_get_clocks(crystal, &sysfreq, &corefreq, &timebase, &brgfreq))
  95                return 0;
  96
  97        pq2_set_clocks(sysfreq, corefreq, timebase, brgfreq);
  98        return 1;
  99}
 100