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-rw-r--r--cpu/mpc8xx/speed.c416
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diff --git a/cpu/mpc8xx/speed.c b/cpu/mpc8xx/speed.c
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-/*
- * (C) Copyright 2000-2004
- * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
- *
- * 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 <mpc8xx.h>
-#include <asm/processor.h>
-
-DECLARE_GLOBAL_DATA_PTR;
-
-#if !defined(CONFIG_8xx_CPUCLK_DEFAULT) || defined(CONFIG_SYS_MEASURE_CPUCLK) || defined(DEBUG)
-
-#define PITC_SHIFT 16
-#define PITR_SHIFT 16
-/* pitc values to time for 58/8192 seconds (about 70.8 milliseconds) */
-#define SPEED_PIT_COUNTS 58
-#define SPEED_PITC ((SPEED_PIT_COUNTS - 1) << PITC_SHIFT)
-#define SPEED_PITC_INIT ((SPEED_PIT_COUNTS + 1) << PITC_SHIFT)
-
-/* Access functions for the Machine State Register */
-static __inline__ unsigned long get_msr(void)
-{
- unsigned long msr;
-
- asm volatile("mfmsr %0" : "=r" (msr) :);
- return msr;
-}
-
-static __inline__ void set_msr(unsigned long msr)
-{
- asm volatile("mtmsr %0" : : "r" (msr));
-}
-
-/* ------------------------------------------------------------------------- */
-
-/*
- * Measure CPU clock speed (core clock GCLK1, GCLK2),
- * also determine bus clock speed (checking bus divider factor)
- *
- * (Approx. GCLK frequency in Hz)
- *
- * Initializes timer 2 and PIT, but disables them before return.
- * [Use timer 2, because MPC823 CPUs mask 0.x do not have timers 3 and 4]
- *
- * When measuring the CPU clock against the PIT, we count cpu clocks
- * for 58/8192 seconds with a prescale divide by 177 for the cpu clock.
- * These strange values for the timing interval and prescaling are used
- * because the formula for the CPU clock is:
- *
- * CPU clock = count * (177 * (8192 / 58))
- *
- * = count * 24999.7241
- *
- * which is very close to
- *
- * = count * 25000
- *
- * Since the count gives the CPU clock divided by 25000, we can get
- * the CPU clock rounded to the nearest 0.1 MHz by
- *
- * CPU clock = ((count + 2) / 4) * 100000;
- *
- * The rounding is important since the measurement is sometimes going
- * to be high or low by 0.025 MHz, depending on exactly how the clocks
- * and counters interact. By rounding we get the exact answer for any
- * CPU clock that is an even multiple of 0.1 MHz.
- */
-
-unsigned long measure_gclk(void)
-{
- volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
- volatile cpmtimer8xx_t *timerp = &immr->im_cpmtimer;
- ulong timer2_val;
- ulong msr_val;
-
-#ifdef CONFIG_SYS_8XX_XIN
- /* dont use OSCM, only use EXTCLK/512 */
- immr->im_clkrst.car_sccr |= SCCR_RTSEL | SCCR_RTDIV;
-#else
- immr->im_clkrst.car_sccr &= ~(SCCR_RTSEL | SCCR_RTDIV);
-#endif
-
- /* Reset + Stop Timer 2, no cascading
- */
- timerp->cpmt_tgcr &= ~(TGCR_CAS2 | TGCR_RST2);
-
- /* Keep stopped, halt in debug mode
- */
- timerp->cpmt_tgcr |= (TGCR_FRZ2 | TGCR_STP2);
-
- /* Timer 2 setup:
- * Output ref. interrupt disable, int. clock
- * Prescale by 177. Note that prescaler divides by value + 1
- * so we must subtract 1 here.
- */
- timerp->cpmt_tmr2 = ((177 - 1) << TMR_PS_SHIFT) | TMR_ICLK_IN_GEN;
-
- timerp->cpmt_tcn2 = 0; /* reset state */
- timerp->cpmt_tgcr |= TGCR_RST2; /* enable timer 2 */
-
- /*
- * PIT setup:
- *
- * We want to time for SPEED_PITC_COUNTS counts (of 8192 Hz),
- * so the count value would be SPEED_PITC_COUNTS - 1.
- * But there would be an uncertainty in the start time of 1/4
- * count since when we enable the PIT the count is not
- * synchronized to the 32768 Hz oscillator. The trick here is
- * to start the count higher and wait until the PIT count
- * changes to the required value before starting timer 2.
- *
- * One count high should be enough, but occasionally the start
- * is off by 1 or 2 counts of 32768 Hz. With the start value
- * set two counts high it seems very reliable.
- */
-
- immr->im_sitk.sitk_pitck = KAPWR_KEY; /* PIT initialization */
- immr->im_sit.sit_pitc = SPEED_PITC_INIT;
-
- immr->im_sitk.sitk_piscrk = KAPWR_KEY;
- immr->im_sit.sit_piscr = CONFIG_SYS_PISCR;
-
- /*
- * Start measurement - disable interrupts, just in case
- */
- msr_val = get_msr ();
- set_msr (msr_val & ~MSR_EE);
-
- immr->im_sit.sit_piscr |= PISCR_PTE;
-
- /* spin until get exact count when we want to start */
- while (immr->im_sit.sit_pitr > SPEED_PITC);
-
- timerp->cpmt_tgcr &= ~TGCR_STP2; /* Start Timer 2 */
- while ((immr->im_sit.sit_piscr & PISCR_PS) == 0);
- timerp->cpmt_tgcr |= TGCR_STP2; /* Stop Timer 2 */
-
- /* re-enable external interrupts if they were on */
- set_msr (msr_val);
-
- /* Disable timer and PIT
- */
- timer2_val = timerp->cpmt_tcn2; /* save before reset timer */
-
- timerp->cpmt_tgcr &= ~(TGCR_RST2 | TGCR_FRZ2 | TGCR_STP2);
- immr->im_sit.sit_piscr &= ~PISCR_PTE;
-
-#if defined(CONFIG_SYS_8XX_XIN)
- /* not using OSCM, using XIN, so scale appropriately */
- return (((timer2_val + 2) / 4) * (CONFIG_SYS_8XX_XIN/512))/8192 * 100000L;
-#else
- return ((timer2_val + 2) / 4) * 100000L; /* convert to Hz */
-#endif
-}
-
-#endif
-
-void get_brgclk(uint sccr)
-{
- uint divider = 0;
-
- switch((sccr&SCCR_DFBRG11)>>11){
- case 0:
- divider = 1;
- break;
- case 1:
- divider = 4;
- break;
- case 2:
- divider = 16;
- break;
- case 3:
- divider = 64;
- break;
- }
- gd->brg_clk = gd->cpu_clk/divider;
-}
-
-#if !defined(CONFIG_8xx_CPUCLK_DEFAULT)
-
-/*
- * get_clocks() fills in gd->cpu_clock depending on CONFIG_8xx_GCLK_FREQ
- * or (if it is not defined) measure_gclk() (which uses the ref clock)
- * from above.
- */
-int get_clocks (void)
-{
- uint immr = get_immr (0); /* Return full IMMR contents */
- volatile immap_t *immap = (immap_t *) (immr & 0xFFFF0000);
- uint sccr = immap->im_clkrst.car_sccr;
- /*
- * If for some reason measuring the gclk frequency won't
- * work, we return the hardwired value.
- * (For example, the cogent CMA286-60 CPU module has no
- * separate oscillator for PITRTCLK)
- */
-#if defined(CONFIG_8xx_GCLK_FREQ)
- gd->cpu_clk = CONFIG_8xx_GCLK_FREQ;
-#elif defined(CONFIG_8xx_OSCLK)
-#define PLPRCR_val(a) ((pll & PLPRCR_ ## a ## _MSK) >> PLPRCR_ ## a ## _SHIFT)
- uint pll = immap->im_clkrst.car_plprcr;
- uint clk;
-
- if ((immr & 0x0FFF) >= MPC8xx_NEW_CLK) { /* MPC866/87x/88x series */
- clk = ((CONFIG_8xx_OSCLK / (PLPRCR_val(PDF)+1)) *
- (PLPRCR_val(MFI) + PLPRCR_val(MFN) / (PLPRCR_val(MFD)+1))) /
- (1<<PLPRCR_val(S));
- } else {
- clk = CONFIG_8xx_OSCLK * (PLPRCR_val(MF)+1);
- }
- if (pll & PLPRCR_CSRC) { /* Low frequency division factor is used */
- gd->cpu_clk = clk / (2 << ((sccr >> 8) & 7));
- } else { /* High frequency division factor is used */
- gd->cpu_clk = clk / (1 << ((sccr >> 5) & 7));
- }
-#else
- gd->cpu_clk = measure_gclk();
-#endif /* CONFIG_8xx_GCLK_FREQ */
-
- if ((sccr & SCCR_EBDF11) == 0) {
- /* No Bus Divider active */
- gd->bus_clk = gd->cpu_clk;
- } else {
- /* The MPC8xx has only one BDF: half clock speed */
- gd->bus_clk = gd->cpu_clk / 2;
- }
-
- get_brgclk(sccr);
-
- return (0);
-}
-
-#else /* CONFIG_8xx_CPUCLK_DEFAULT defined, use dynamic clock setting */
-
-static long init_pll_866 (long clk);
-
-/* This function sets up PLL (init_pll_866() is called) and
- * fills gd->cpu_clk and gd->bus_clk according to the environment
- * variable 'cpuclk' or to CONFIG_8xx_CPUCLK_DEFAULT (if 'cpuclk'
- * contains invalid value).
- * This functions requires an MPC866 or newer series CPU.
- */
-int get_clocks_866 (void)
-{
- volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
- char tmp[64];
- long cpuclk = 0;
- long sccr_reg;
-
- if (getenv_r ("cpuclk", tmp, sizeof (tmp)) > 0)
- cpuclk = simple_strtoul (tmp, NULL, 10) * 1000000;
-
- if ((CONFIG_SYS_8xx_CPUCLK_MIN > cpuclk) || (CONFIG_SYS_8xx_CPUCLK_MAX < cpuclk))
- cpuclk = CONFIG_8xx_CPUCLK_DEFAULT;
-
- gd->cpu_clk = init_pll_866 (cpuclk);
-#if defined(CONFIG_SYS_MEASURE_CPUCLK)
- gd->cpu_clk = measure_gclk ();
-#endif
-
- get_brgclk(immr->im_clkrst.car_sccr);
-
- /* if cpu clock <= 66 MHz then set bus division factor to 1,
- * otherwise set it to 2
- */
- sccr_reg = immr->im_clkrst.car_sccr;
- sccr_reg &= ~SCCR_EBDF11;
-
- if (gd->cpu_clk <= 66000000) {
- sccr_reg |= SCCR_EBDF00; /* bus division factor = 1 */
- gd->bus_clk = gd->cpu_clk;
- } else {
- sccr_reg |= SCCR_EBDF01; /* bus division factor = 2 */
- gd->bus_clk = gd->cpu_clk / 2;
- }
- immr->im_clkrst.car_sccr = sccr_reg;
-
- return (0);
-}
-
-/* Adjust sdram refresh rate to actual CPU clock.
- */
-int sdram_adjust_866 (void)
-{
- volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
- long mamr;
-
- mamr = immr->im_memctl.memc_mamr;
- mamr &= ~MAMR_PTA_MSK;
- mamr |= ((gd->cpu_clk / CONFIG_SYS_PTA_PER_CLK) << MAMR_PTA_SHIFT);
- immr->im_memctl.memc_mamr = mamr;
-
- return (0);
-}
-
-/* Configure PLL for MPC866/859/885 CPU series
- * PLL multiplication factor is set to the value nearest to the desired clk,
- * assuming a oscclk of 10 MHz.
- */
-static long init_pll_866 (long clk)
-{
- extern void plprcr_write_866 (long);
-
- volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
- long n, plprcr;
- char mfi, mfn, mfd, s, pdf;
- long step_mfi, step_mfn;
-
- if (clk < 20000000) {
- clk *= 2;
- pdf = 1;
- } else {
- pdf = 0;
- }
-
- if (clk < 40000000) {
- s = 2;
- step_mfi = CONFIG_8xx_OSCLK / 4;
- mfd = 7;
- step_mfn = CONFIG_8xx_OSCLK / 30;
- } else if (clk < 80000000) {
- s = 1;
- step_mfi = CONFIG_8xx_OSCLK / 2;
- mfd = 14;
- step_mfn = CONFIG_8xx_OSCLK / 30;
- } else {
- s = 0;
- step_mfi = CONFIG_8xx_OSCLK;
- mfd = 29;
- step_mfn = CONFIG_8xx_OSCLK / 30;
- }
-
- /* Calculate integer part of multiplication factor
- */
- n = clk / step_mfi;
- mfi = (char)n;
-
- /* Calculate numerator of fractional part of multiplication factor
- */
- n = clk - (n * step_mfi);
- mfn = (char)(n / step_mfn);
-
- /* Calculate effective clk
- */
- n = ((mfi * step_mfi) + (mfn * step_mfn)) / (pdf + 1);
-
- immr->im_clkrstk.cark_plprcrk = KAPWR_KEY;
-
- plprcr = (immr->im_clkrst.car_plprcr & ~(PLPRCR_MFN_MSK
- | PLPRCR_MFD_MSK | PLPRCR_S_MSK
- | PLPRCR_MFI_MSK | PLPRCR_DBRMO
- | PLPRCR_PDF_MSK))
- | (mfn << PLPRCR_MFN_SHIFT)
- | (mfd << PLPRCR_MFD_SHIFT)
- | (s << PLPRCR_S_SHIFT)
- | (mfi << PLPRCR_MFI_SHIFT)
- | (pdf << PLPRCR_PDF_SHIFT);
-
- if( (mfn > 0) && ((mfd / mfn) > 10) )
- plprcr |= PLPRCR_DBRMO;
-
- plprcr_write_866 (plprcr); /* set value using SIU4/9 workaround */
- immr->im_clkrstk.cark_plprcrk = 0x00000000;
-
- return (n);
-}
-
-#endif /* CONFIG_8xx_CPUCLK_DEFAULT */
-
-#if defined(CONFIG_TQM8xxL) && !defined(CONFIG_TQM866M) \
- && !defined(CONFIG_TQM885D)
-/*
- * Adjust sdram refresh rate to actual CPU clock
- * and set timebase source according to actual CPU clock
- */
-int adjust_sdram_tbs_8xx (void)
-{
- volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
- long mamr;
- long sccr;
-
- mamr = immr->im_memctl.memc_mamr;
- mamr &= ~MAMR_PTA_MSK;
- mamr |= ((gd->cpu_clk / CONFIG_SYS_PTA_PER_CLK) << MAMR_PTA_SHIFT);
- immr->im_memctl.memc_mamr = mamr;
-
- if (gd->cpu_clk < 67000000) {
- sccr = immr->im_clkrst.car_sccr;
- sccr |= SCCR_TBS;
- immr->im_clkrst.car_sccr = sccr;
- }
-
- return (0);
-}
-#endif /* CONFIG_TQM8xxL/M, !TQM866M, !TQM885D */
-
-/* ------------------------------------------------------------------------- */