uboot/arch/m68k/cpu/mcf5227x/speed.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 *
   4 * Copyright (C) 2004-2007, 2012 Freescale Semiconductor, Inc.
   5 * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
   6 */
   7
   8#include <common.h>
   9#include <asm/processor.h>
  10
  11#include <asm/immap.h>
  12#include <asm/io.h>
  13
  14DECLARE_GLOBAL_DATA_PTR;
  15
  16/*
  17 * Low Power Divider specifications
  18 */
  19#define CLOCK_LPD_MIN           (1 << 0)        /* Divider (decoded) */
  20#define CLOCK_LPD_MAX           (1 << 15)       /* Divider (decoded) */
  21
  22#define CLOCK_PLL_FVCO_MAX      540000000
  23#define CLOCK_PLL_FVCO_MIN      300000000
  24
  25#define CLOCK_PLL_FSYS_MAX      266666666
  26#define CLOCK_PLL_FSYS_MIN      100000000
  27#define MHZ                     1000000
  28
  29void clock_enter_limp(int lpdiv)
  30{
  31        ccm_t *ccm = (ccm_t *)MMAP_CCM;
  32        int i, j;
  33
  34        /* Check bounds of divider */
  35        if (lpdiv < CLOCK_LPD_MIN)
  36                lpdiv = CLOCK_LPD_MIN;
  37        if (lpdiv > CLOCK_LPD_MAX)
  38                lpdiv = CLOCK_LPD_MAX;
  39
  40        /* Round divider down to nearest power of two */
  41        for (i = 0, j = lpdiv; j != 1; j >>= 1, i++) ;
  42
  43        /* Apply the divider to the system clock */
  44        clrsetbits_be16(&ccm->cdr, 0x0f00, CCM_CDR_LPDIV(i));
  45
  46        /* Enable Limp Mode */
  47        setbits_be16(&ccm->misccr, CCM_MISCCR_LIMP);
  48}
  49
  50/*
  51 * brief   Exit Limp mode
  52 * warning The PLL should be set and locked prior to exiting Limp mode
  53 */
  54void clock_exit_limp(void)
  55{
  56        ccm_t *ccm = (ccm_t *)MMAP_CCM;
  57        pll_t *pll = (pll_t *)MMAP_PLL;
  58
  59        /* Exit Limp mode */
  60        clrbits_be16(&ccm->misccr, CCM_MISCCR_LIMP);
  61
  62        /* Wait for the PLL to lock */
  63        while (!(in_be32(&pll->psr) & PLL_PSR_LOCK))
  64                ;
  65}
  66
  67/*
  68 * get_clocks() fills in gd->cpu_clock and gd->bus_clk
  69 */
  70int get_clocks(void)
  71{
  72
  73        ccm_t *ccm = (ccm_t *)MMAP_CCM;
  74        pll_t *pll = (pll_t *)MMAP_PLL;
  75        int vco, temp, pcrvalue, pfdr;
  76        u8 bootmode;
  77
  78        pcrvalue = in_be32(&pll->pcr) & 0xFF0F0FFF;
  79        pfdr = pcrvalue >> 24;
  80
  81        if (pfdr == 0x1E)
  82                bootmode = 0;   /* Normal Mode */
  83
  84#ifdef CONFIG_CF_SBF
  85        bootmode = 3;           /* Serial Mode */
  86#endif
  87
  88        if (bootmode == 0) {
  89                /* Normal mode */
  90                vco = ((in_be32(&pll->pcr) & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
  91                if ((vco < CLOCK_PLL_FVCO_MIN) || (vco > CLOCK_PLL_FVCO_MAX)) {
  92                        /* Default value */
  93                        pcrvalue = (in_be32(&pll->pcr) & 0x00FFFFFF);
  94                        pcrvalue |= 0x1E << 24;
  95                        out_be32(&pll->pcr, pcrvalue);
  96                        vco =
  97                            ((in_be32(&pll->pcr) & 0xFF000000) >> 24) *
  98                            CONFIG_SYS_INPUT_CLKSRC;
  99                }
 100                gd->arch.vco_clk = vco; /* Vco clock */
 101        } else if (bootmode == 3) {
 102                /* serial mode */
 103                vco = ((in_be32(&pll->pcr) & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
 104                gd->arch.vco_clk = vco; /* Vco clock */
 105        }
 106
 107        if ((in_be16(&ccm->ccr) & CCM_MISCCR_LIMP) == CCM_MISCCR_LIMP) {
 108                /* Limp mode */
 109        } else {
 110                gd->arch.inp_clk = CONFIG_SYS_INPUT_CLKSRC; /* Input clock */
 111
 112                temp = (in_be32(&pll->pcr) & PLL_PCR_OUTDIV1_MASK) + 1;
 113                gd->cpu_clk = vco / temp;       /* cpu clock */
 114
 115                temp = ((in_be32(&pll->pcr) & PLL_PCR_OUTDIV2_MASK) >> 4) + 1;
 116                gd->arch.flb_clk = vco / temp;  /* flexbus clock */
 117                gd->bus_clk = gd->arch.flb_clk;
 118        }
 119
 120#ifdef CONFIG_SYS_I2C_FSL
 121        gd->arch.i2c1_clk = gd->bus_clk;
 122#endif
 123
 124        return (0);
 125}
 126