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/*
*
* (C) Copyright 2000-2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* Copyright (C) 2004-2008 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;
/* PLL min/max specifications */
#define MAX_FVCO 500000 /* KHz */
#define MAX_FSYS 80000 /* KHz */
#define MIN_FSYS 58333 /* KHz */
#ifdef CONFIG_MCF5301x
#define FREF 20000 /* KHz */
#define MAX_MFD 63 /* Multiplier */
#define MIN_MFD 0 /* Multiplier */
#define USBDIV 8
/* Low Power Divider specifications */
#define MIN_LPD (0) /* Divider (not encoded) */
#define MAX_LPD (15) /* Divider (not encoded) */
#define DEFAULT_LPD (0) /* Divider (not encoded) */
#endif
#ifdef CONFIG_MCF532x
#define FREF 16000 /* KHz */
#define MAX_MFD 135 /* Multiplier */
#define MIN_MFD 88 /* Multiplier */
/* Low Power Divider specifications */
#define MIN_LPD (1 << 0) /* Divider (not encoded) */
#define MAX_LPD (1 << 15) /* Divider (not encoded) */
#define DEFAULT_LPD (1 << 1) /* Divider (not encoded) */
#endif
#define BUSDIV 6 /* Divider */
/* Get the value of the current system clock */
int get_sys_clock(void)
{
volatile ccm_t *ccm = (volatile ccm_t *)(MMAP_CCM);
volatile pll_t *pll = (volatile pll_t *)(MMAP_PLL);
int divider;
/* Test to see if device is in LIMP mode */
if (ccm->misccr & CCM_MISCCR_LIMP) {
divider = ccm->cdr & CCM_CDR_LPDIV(0xF);
#ifdef CONFIG_MCF5301x
return (FREF / (3 * (1 << divider)));
#endif
#ifdef CONFIG_MCF532x
return (FREF / (2 << divider));
#endif
} else {
#ifdef CONFIG_MCF5301x
u32 pfdr = (pll->pcr & 0x3F) + 1;
u32 refdiv = (1 << ((pll->pcr & PLL_PCR_REFDIV(7)) >> 8));
u32 busdiv = ((pll->pdr & 0x00F0) >> 4) + 1;
return (((FREF * pfdr) / refdiv) / busdiv);
#endif
#ifdef CONFIG_MCF532x
return ((FREF * pll->pfdr) / (BUSDIV * 4));
#endif
}
}
/*
* Initialize the Low Power Divider circuit
*
* Parameters:
* div Desired system frequency divider
*
* Return Value:
* The resulting output system frequency
*/
int clock_limp(int div)
{
volatile ccm_t *ccm = (volatile ccm_t *)(MMAP_CCM);
u32 temp;
/* Check bounds of divider */
if (div < MIN_LPD)
div = MIN_LPD;
if (div > MAX_LPD)
div = MAX_LPD;
/* Save of the current value of the SSIDIV so we don't overwrite the value */
temp = (ccm->cdr & CCM_CDR_SSIDIV(0xFF));
/* Apply the divider to the system clock */
ccm->cdr = (CCM_CDR_LPDIV(div) | CCM_CDR_SSIDIV(temp));
ccm->misccr |= CCM_MISCCR_LIMP;
return (FREF / (3 * (1 << div)));
}
/* Exit low power LIMP mode */
int clock_exit_limp(void)
{
volatile ccm_t *ccm = (volatile ccm_t *)(MMAP_CCM);
int fout;
/* Exit LIMP mode */
ccm->misccr &= (~CCM_MISCCR_LIMP);
/* Wait for PLL to lock */
while (!(ccm->misccr & CCM_MISCCR_PLL_LOCK)) ;
fout = get_sys_clock();
return fout;
}
/* Initialize the PLL
*
* Parameters:
* fref PLL reference clock frequency in KHz
* fsys Desired PLL output frequency in KHz
* flags Operating parameters
*
* Return Value:
* The resulting output system frequency
*/
int clock_pll(int fsys, int flags)
{
#ifdef CONFIG_MCF532x
volatile u32 *sdram_workaround = (volatile u32 *)(MMAP_SDRAM + 0x80);
#endif
volatile sdram_t *sdram = (volatile sdram_t *)(MMAP_SDRAM);
volatile pll_t *pll = (volatile pll_t *)(MMAP_PLL);
int fref, temp, fout, mfd;
u32 i;
fref = FREF;
if (fsys == 0) {
/* Return current PLL output */
#ifdef CONFIG_MCF5301x
u32 busdiv = ((pll->pdr >> 4) & 0x0F) + 1;
mfd = (pll->pcr & 0x3F) + 1;
return (fref * mfd) / busdiv;
#endif
#ifdef CONFIG_MCF532x
mfd = pll->pfdr;
return (fref * mfd / (BUSDIV * 4));
#endif
}
/* Check bounds of requested system clock */
if (fsys > MAX_FSYS)
fsys = MAX_FSYS;
if (fsys < MIN_FSYS)
fsys = MIN_FSYS;
/*
* Multiplying by 100 when calculating the temp value,
* and then dividing by 100 to calculate the mfd allows
* for exact values without needing to include floating
* point libraries.
*/
temp = (100 * fsys) / fref;
#ifdef CONFIG_MCF5301x
mfd = (BUSDIV * temp) / 100;
/* Determine the output frequency for selected values */
fout = ((fref * mfd) / BUSDIV);
#endif
#ifdef CONFIG_MCF532x
mfd = (4 * BUSDIV * temp) / 100;
/* Determine the output frequency for selected values */
fout = ((fref * mfd) / (BUSDIV * 4));
#endif
/* must not tamper with SDRAMC if running from SDRAM */
#if !defined(CONFIG_MONITOR_IS_IN_RAM)
/*
* Check to see if the SDRAM has already been initialized.
* If it has then the SDRAM needs to be put into self refresh
* mode before reprogramming the PLL.
*/
if (sdram->ctrl & SDRAMC_SDCR_REF)
sdram->ctrl &= ~SDRAMC_SDCR_CKE;
/*
* Initialize the PLL to generate the new system clock frequency.
* The device must be put into LIMP mode to reprogram the PLL.
*/
/* Enter LIMP mode */
clock_limp(DEFAULT_LPD);
#ifdef CONFIG_MCF5301x
pll->pdr =
PLL_PDR_OUTDIV1((BUSDIV / 3) - 1) |
PLL_PDR_OUTDIV2(BUSDIV - 1) |
PLL_PDR_OUTDIV3((BUSDIV / 2) - 1) |
PLL_PDR_OUTDIV4(USBDIV - 1);
pll->pcr &= PLL_PCR_FBDIV_UNMASK;
pll->pcr |= PLL_PCR_FBDIV(mfd - 1);
#endif
#ifdef CONFIG_MCF532x
/* Reprogram PLL for desired fsys */
pll->podr = (PLL_PODR_CPUDIV(BUSDIV / 3) | PLL_PODR_BUSDIV(BUSDIV));
pll->pfdr = mfd;
#endif
/* Exit LIMP mode */
clock_exit_limp();
/* Return the SDRAM to normal operation if it is in use. */
if (sdram->ctrl & SDRAMC_SDCR_REF)
sdram->ctrl |= SDRAMC_SDCR_CKE;
#ifdef CONFIG_MCF532x
/*
* software workaround for SDRAM opeartion after exiting LIMP
* mode errata
*/
*sdram_workaround = CONFIG_SYS_SDRAM_BASE;
#endif
/* wait for DQS logic to relock */
for (i = 0; i < 0x200; i++) ;
#endif /* !defined(CONFIG_MONITOR_IS_IN_RAM) */
return fout;
}
/* get_clocks() fills in gd->cpu_clock and gd->bus_clk */
int get_clocks(void)
{
gd->bus_clk = clock_pll(CONFIG_SYS_CLK / 1000, 0) * 1000;
gd->cpu_clk = (gd->bus_clk * 3);
#ifdef CONFIG_FSL_I2C
gd->i2c1_clk = gd->bus_clk;
#endif
return (0);
}
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