121 lines
3.0 KiB
C
121 lines
3.0 KiB
C
/*
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*
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* Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
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* TsiChung Liew (Tsi-Chung.Liew@freescale.com)
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <asm/processor.h>
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#include <asm/immap.h>
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DECLARE_GLOBAL_DATA_PTR;
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/*
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* Low Power Divider specifications
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*/
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#define CLOCK_LPD_MIN (1 << 0) /* Divider (decoded) */
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#define CLOCK_LPD_MAX (1 << 15) /* Divider (decoded) */
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#define CLOCK_PLL_FVCO_MAX 540000000
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#define CLOCK_PLL_FVCO_MIN 300000000
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#define CLOCK_PLL_FSYS_MAX 266666666
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#define CLOCK_PLL_FSYS_MIN 100000000
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#define MHZ 1000000
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void clock_enter_limp(int lpdiv)
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{
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volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
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int i, j;
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/* Check bounds of divider */
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if (lpdiv < CLOCK_LPD_MIN)
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lpdiv = CLOCK_LPD_MIN;
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if (lpdiv > CLOCK_LPD_MAX)
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lpdiv = CLOCK_LPD_MAX;
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/* Round divider down to nearest power of two */
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for (i = 0, j = lpdiv; j != 1; j >>= 1, i++) ;
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/* Apply the divider to the system clock */
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ccm->cdr = (ccm->cdr & 0xF0FF) | CCM_CDR_LPDIV(i);
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/* Enable Limp Mode */
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ccm->misccr |= CCM_MISCCR_LIMP;
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}
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/*
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* brief Exit Limp mode
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* warning The PLL should be set and locked prior to exiting Limp mode
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*/
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void clock_exit_limp(void)
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{
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volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
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volatile pll_t *pll = (volatile pll_t *)MMAP_PLL;
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/* Exit Limp mode */
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ccm->misccr &= ~CCM_MISCCR_LIMP;
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/* Wait for the PLL to lock */
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while (!(pll->psr & PLL_PSR_LOCK)) ;
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}
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/*
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* get_clocks() fills in gd->cpu_clock and gd->bus_clk
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*/
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int get_clocks(void)
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{
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volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
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volatile pll_t *pll = (volatile pll_t *)MMAP_PLL;
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int vco, temp, pcrvalue, pfdr;
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u8 bootmode;
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bootmode = (ccm->ccr & 0x000C) >> 2;
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pcrvalue = pll->pcr & 0xFF0F0FFF;
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pfdr = pcrvalue >> 24;
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if (pfdr != 0x1E) {
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/* serial mode */
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} else {
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/* Normal Mode */
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vco = pfdr * CFG_INPUT_CLKSRC;
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gd->vco_clk = vco;
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}
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if ((ccm->ccr & CCM_MISCCR_LIMP) == CCM_MISCCR_LIMP) {
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/* Limp mode */
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} else {
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gd->inp_clk = CFG_INPUT_CLKSRC; /* Input clock */
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temp = (pll->pcr & PLL_PCR_OUTDIV1_MASK) + 1;
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gd->cpu_clk = vco / temp; /* cpu clock */
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temp = ((pll->pcr & PLL_PCR_OUTDIV2_MASK) >> 4) + 1;
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gd->flb_clk = vco / temp; /* flexbus clock */
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gd->bus_clk = gd->flb_clk;
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}
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return (0);
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}
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