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
  20 static 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  */
  28 int 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. */
  75 void 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
  90 int 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 }