1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2000-2004 4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 5 */ 6 7 #include <common.h> 8 #include <mpc8xx.h> 9 #include <asm/processor.h> 10 #include <asm/io.h> 11 12 DECLARE_GLOBAL_DATA_PTR; 13 14 /* 15 * get_clocks() fills in gd->cpu_clock depending on CONFIG_8xx_GCLK_FREQ 16 */ 17 int get_clocks(void) 18 { 19 immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR; 20 uint sccr = in_be32(&immap->im_clkrst.car_sccr); 21 uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2); 22 23 /* 24 * If for some reason measuring the gclk frequency won't 25 * work, we return the hardwired value. 26 * (For example, the cogent CMA286-60 CPU module has no 27 * separate oscillator for PITRTCLK) 28 */ 29 gd->cpu_clk = CONFIG_8xx_GCLK_FREQ; 30 31 if ((sccr & SCCR_EBDF11) == 0) { 32 /* No Bus Divider active */ 33 gd->bus_clk = gd->cpu_clk; 34 } else { 35 /* The MPC8xx has only one BDF: half clock speed */ 36 gd->bus_clk = gd->cpu_clk / 2; 37 } 38 39 gd->arch.brg_clk = gd->cpu_clk / divider; 40 41 return 0; 42 } 43