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/*
*
* Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
* TsiChung Liew (Tsi-Chung.Liew@freescale.com)
*
* 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;
/*
* Low Power Divider specifications
*/
#define CLOCK_LPD_MIN (1 << 0) /* Divider (decoded) */
#define CLOCK_LPD_MAX (1 << 15) /* Divider (decoded) */
#define CLOCK_PLL_FVCO_MAX 540000000
#define CLOCK_PLL_FVCO_MIN 300000000
#define CLOCK_PLL_FSYS_MAX 266666666
#define CLOCK_PLL_FSYS_MIN 100000000
#define MHZ 1000000
void clock_enter_limp(int lpdiv)
{
volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
int i, j;
/* Check bounds of divider */
if (lpdiv < CLOCK_LPD_MIN)
lpdiv = CLOCK_LPD_MIN;
if (lpdiv > CLOCK_LPD_MAX)
lpdiv = CLOCK_LPD_MAX;
/* Round divider down to nearest power of two */
for (i = 0, j = lpdiv; j != 1; j >>= 1, i++) ;
/* Apply the divider to the system clock */
ccm->cdr = (ccm->cdr & 0xF0FF) | CCM_CDR_LPDIV(i);
/* Enable Limp Mode */
ccm->misccr |= CCM_MISCCR_LIMP;
}
/*
* brief Exit Limp mode
* warning The PLL should be set and locked prior to exiting Limp mode
*/
void clock_exit_limp(void)
{
volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
volatile pll_t *pll = (volatile pll_t *)MMAP_PLL;
/* Exit Limp mode */
ccm->misccr &= ~CCM_MISCCR_LIMP;
/* Wait for the PLL to lock */
while (!(pll->psr & PLL_PSR_LOCK)) ;
}
/*
* get_clocks() fills in gd->cpu_clock and gd->bus_clk
*/
int get_clocks(void)
{
volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
volatile pll_t *pll = (volatile pll_t *)MMAP_PLL;
int vco, temp, pcrvalue, pfdr;
u8 bootmode;
bootmode = (ccm->ccr & 0x000C) >> 2;
pcrvalue = pll->pcr & 0xFF0F0FFF;
pfdr = pcrvalue >> 24;
if (pfdr != 0x1E) {
/* serial mode */
} else {
/* Normal Mode */
vco = pfdr * CFG_INPUT_CLKSRC;
gd->vco_clk = vco;
}
if ((ccm->ccr & CCM_MISCCR_LIMP) == CCM_MISCCR_LIMP) {
/* Limp mode */
} else {
gd->inp_clk = CFG_INPUT_CLKSRC; /* Input clock */
temp = (pll->pcr & PLL_PCR_OUTDIV1_MASK) + 1;
gd->cpu_clk = vco / temp; /* cpu clock */
temp = ((pll->pcr & PLL_PCR_OUTDIV2_MASK) >> 4) + 1;
gd->flb_clk = vco / temp; /* flexbus clock */
gd->bus_clk = gd->flb_clk;
}
return (0);
}
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