1 /* 2 * (C) Copyright 2000-2004 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <mpc8xx.h> 10 #include <asm/processor.h> 11 #include <asm/io.h> 12 13 DECLARE_GLOBAL_DATA_PTR; 14 15 /* 16 * get_clocks() fills in gd->cpu_clock depending on CONFIG_8xx_GCLK_FREQ 17 */ 18 int get_clocks(void) 19 { 20 immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR; 21 uint sccr = in_be32(&immap->im_clkrst.car_sccr); 22 uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2); 23 24 /* 25 * If for some reason measuring the gclk frequency won't 26 * work, we return the hardwired value. 27 * (For example, the cogent CMA286-60 CPU module has no 28 * separate oscillator for PITRTCLK) 29 */ 30 gd->cpu_clk = CONFIG_8xx_GCLK_FREQ; 31 32 if ((sccr & SCCR_EBDF11) == 0) { 33 /* No Bus Divider active */ 34 gd->bus_clk = gd->cpu_clk; 35 } else { 36 /* The MPC8xx has only one BDF: half clock speed */ 37 gd->bus_clk = gd->cpu_clk / 2; 38 } 39 40 gd->arch.brg_clk = gd->cpu_clk / divider; 41 42 return 0; 43 } 44