--- /dev/null
+/*
+ * (C) Copyright 2000-2004
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#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->arch.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_f("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 */
+
+/* ------------------------------------------------------------------------- */
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