u-boot/arch/m68k/cpu/mcf5227x/speed.c

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/*
*
* Copyright (C) 2004-2007, 2012 Freescale Semiconductor, Inc.
* TsiChung Liew (Tsi-Chung.Liew@freescale.com)
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/processor.h>
#include <asm/immap.h>
#include <asm/io.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)
{
ccm_t *ccm = (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 */
clrsetbits_be16(&ccm->cdr, 0x0f00, CCM_CDR_LPDIV(i));
/* Enable Limp Mode */
setbits_be16(&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)
{
ccm_t *ccm = (ccm_t *)MMAP_CCM;
pll_t *pll = (pll_t *)MMAP_PLL;
/* Exit Limp mode */
clrbits_be16(&ccm->misccr, CCM_MISCCR_LIMP);
/* Wait for the PLL to lock */
while (!(in_be32(&pll->psr) & PLL_PSR_LOCK))
;
}
/*
* get_clocks() fills in gd->cpu_clock and gd->bus_clk
*/
int get_clocks(void)
{
ccm_t *ccm = (ccm_t *)MMAP_CCM;
pll_t *pll = (pll_t *)MMAP_PLL;
int vco, temp, pcrvalue, pfdr;
u8 bootmode;
pcrvalue = in_be32(&pll->pcr) & 0xFF0F0FFF;
pfdr = pcrvalue >> 24;
if (pfdr == 0x1E)
bootmode = 0; /* Normal Mode */
#ifdef CONFIG_CF_SBF
bootmode = 3; /* Serial Mode */
#endif
if (bootmode == 0) {
/* Normal mode */
vco = ((in_be32(&pll->pcr) & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
if ((vco < CLOCK_PLL_FVCO_MIN) || (vco > CLOCK_PLL_FVCO_MAX)) {
/* Default value */
pcrvalue = (in_be32(&pll->pcr) & 0x00FFFFFF);
pcrvalue |= 0x1E << 24;
out_be32(&pll->pcr, pcrvalue);
vco =
((in_be32(&pll->pcr) & 0xFF000000) >> 24) *
CONFIG_SYS_INPUT_CLKSRC;
}
gd->arch.vco_clk = vco; /* Vco clock */
} else if (bootmode == 3) {
/* serial mode */
vco = ((in_be32(&pll->pcr) & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
gd->arch.vco_clk = vco; /* Vco clock */
}
if ((in_be16(&ccm->ccr) & CCM_MISCCR_LIMP) == CCM_MISCCR_LIMP) {
/* Limp mode */
} else {
gd->arch.inp_clk = CONFIG_SYS_INPUT_CLKSRC; /* Input clock */
temp = (in_be32(&pll->pcr) & PLL_PCR_OUTDIV1_MASK) + 1;
gd->cpu_clk = vco / temp; /* cpu clock */
temp = ((in_be32(&pll->pcr) & PLL_PCR_OUTDIV2_MASK) >> 4) + 1;
gd->arch.flb_clk = vco / temp; /* flexbus clock */
gd->bus_clk = gd->arch.flb_clk;
}
#ifdef CONFIG_SYS_I2C_FSL
gd->arch.i2c1_clk = gd->bus_clk;
#endif
return (0);
}