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/*
* Copyright (C) 2005-2008 Atmel Corporation
*
* 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/io.h>
#include <asm/arch/clk.h>
#include <asm/arch/memory-map.h>
#include <asm/arch/portmux.h>
#include "sm.h"
void clk_init(void)
{
uint32_t cksel;
/* in case of soft resets, disable watchdog */
sm_writel(WDT_CTRL, SM_BF(KEY, 0x55));
sm_writel(WDT_CTRL, SM_BF(KEY, 0xaa));
#ifdef CONFIG_PLL
/* Initialize the PLL */
sm_writel(PM_PLL0, (SM_BF(PLLCOUNT, CFG_PLL0_SUPPRESS_CYCLES)
| SM_BF(PLLMUL, CFG_PLL0_MUL - 1)
| SM_BF(PLLDIV, CFG_PLL0_DIV - 1)
| SM_BF(PLLOPT, CFG_PLL0_OPT)
| SM_BF(PLLOSC, 0)
| SM_BIT(PLLEN)));
/* Wait for lock */
while (!(sm_readl(PM_ISR) & SM_BIT(LOCK0))) ;
#endif
/* Set up clocks for the CPU and all peripheral buses */
cksel = 0;
if (CFG_CLKDIV_CPU)
cksel |= SM_BIT(CPUDIV) | SM_BF(CPUSEL, CFG_CLKDIV_CPU - 1);
if (CFG_CLKDIV_HSB)
cksel |= SM_BIT(HSBDIV) | SM_BF(HSBSEL, CFG_CLKDIV_HSB - 1);
if (CFG_CLKDIV_PBA)
cksel |= SM_BIT(PBADIV) | SM_BF(PBASEL, CFG_CLKDIV_PBA - 1);
if (CFG_CLKDIV_PBB)
cksel |= SM_BIT(PBBDIV) | SM_BF(PBBSEL, CFG_CLKDIV_PBB - 1);
sm_writel(PM_CKSEL, cksel);
#ifdef CONFIG_PLL
/* Use PLL0 as main clock */
sm_writel(PM_MCCTRL, SM_BIT(PLLSEL));
#endif
}
unsigned long __gclk_set_rate(unsigned int id, enum gclk_parent parent,
unsigned long rate, unsigned long parent_rate)
{
unsigned long divider;
if (rate == 0 || parent_rate == 0) {
sm_writel(PM_GCCTRL(id), 0);
return 0;
}
divider = (parent_rate + rate / 2) / rate;
if (divider <= 1) {
sm_writel(PM_GCCTRL(id), parent | SM_BIT(CEN));
rate = parent_rate;
} else {
divider = min(255, divider / 2 - 1);
sm_writel(PM_GCCTRL(id), parent | SM_BIT(CEN) | SM_BIT(DIVEN)
| SM_BF(DIV, divider));
rate = parent_rate / (2 * (divider + 1));
}
return rate;
}
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