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 uint immr = get_immr(0); /* Return full IMMR contents */ 21 immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000); 22 uint sccr = in_be32(&immap->im_clkrst.car_sccr); 23 uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2); 24 25 /* 26 * If for some reason measuring the gclk frequency won't 27 * work, we return the hardwired value. 28 * (For example, the cogent CMA286-60 CPU module has no 29 * separate oscillator for PITRTCLK) 30 */ 31 gd->cpu_clk = CONFIG_8xx_GCLK_FREQ; 32 33 if ((sccr & SCCR_EBDF11) == 0) { 34 /* No Bus Divider active */ 35 gd->bus_clk = gd->cpu_clk; 36 } else { 37 /* The MPC8xx has only one BDF: half clock speed */ 38 gd->bus_clk = gd->cpu_clk / 2; 39 } 40 41 gd->arch.brg_clk = gd->cpu_clk / divider; 42 43 return 0; 44 } 45