arch/powerpc/cpu/mpc5xx/speed.c

   1 /*
   2  * (C) Copyright 2003
   3  * Martin Winistoerfer, martinwinistoerfer@gmx.ch.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * File:                speed.c
  10  *
  11  * Discription:         Provides cpu speed calculation
  12  *
  13  */
  14
  15 #include <common.h>
  16 #include <mpc5xx.h>
  17 #include <asm/processor.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 /*
  22  * Get cpu and bus clock
  23  */
  24 int get_clocks (void)
  25 {
  26         volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
  27
  28 #ifndef CONFIG_5xx_GCLK_FREQ
  29         uint divf = (immr->im_clkrst.car_plprcr & PLPRCR_DIVF_MSK);
  30         uint mf = ((immr->im_clkrst.car_plprcr & PLPRCR_MF_MSK) >> PLPRCR_MF_SHIFT);
  31         ulong vcoout;
  32
  33         vcoout = (CONFIG_SYS_OSC_CLK / (divf + 1)) * (mf + 1) * 2;
  34         if(immr->im_clkrst.car_plprcr & PLPRCR_CSRC_MSK) {
  35                 gd->cpu_clk = vcoout / (2^(((immr->im_clkrst.car_sccr & SCCR_DFNL_MSK) >> SCCR_DFNL_SHIFT) + 1));
  36         } else {
  37                 gd->cpu_clk = vcoout / (2^(immr->im_clkrst.car_sccr & SCCR_DFNH_MSK));
  38         }
  39
  40 #else /* CONFIG_5xx_GCLK_FREQ */
  41         gd->bus_clk = CONFIG_5xx_GCLK_FREQ;
  42 #endif /* CONFIG_5xx_GCLK_FREQ */
  43
  44         if ((immr->im_clkrst.car_sccr & SCCR_EBDF11) == 0) {
  45                 /* No Bus Divider active */
  46                 gd->bus_clk = gd->cpu_clk;
  47         } else {
  48                 /* CLKOUT is GCLK / 2 */
  49                 gd->bus_clk = gd->cpu_clk / 2;
  50         }
  51         return (0);
  52 }