speed.c

U-boot源码 ARM7启动代码

/*
 *
 * (C) Copyright 2000-2003
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
 * TsiChung Liew ([e-mail])
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <asm/processor.h>

#include <asm/immap.h>

DECLARE_GLOBAL_DATA_PTR;
/*
 * get_clocks() fills in gd->cpu_clock and gd->bus_clk
 */
int get_clocks(void)
{
	volatile pll_t *pll = (volatile pll_t *)(MMAP_PLL);

	pll->syncr = PLL_SYNCR_MFD(1);

	while (!(pll->synsr & PLL_SYNSR_LOCK));

	gd->bus_clk = CFG_CLK;
	gd->cpu_clk = (gd->bus_clk * 2);

	return (0);
}