* Make sure to use a bus clock divider of 2 only when running TQM8xxM

[karo-tx-uboot.git] / cpu / mpc8xx / speed.c

diff --git a/cpu/mpc8xx/speed.c b/cpu/mpc8xx/speed.c
index 8583eef63c75500a9aab64bd25108e79d0b45c6d..aebfbcb1d77995cb1387297b5b5c752688749afa 100644 (file)
--- a/cpu/mpc8xx/speed.c
+++ b/cpu/mpc8xx/speed.c
@@ -25,7 +25,7 @@
 #include <mpc8xx.h>
 #include <asm/processor.h>
 
-#ifndef CONFIG_TQM866M
+#if !defined(CONFIG_TQM866M) || defined(CFG_MEASURE_CPUCLK)
 
 #define PITC_SHIFT 16
 #define PITR_SHIFT 16
@@ -64,18 +64,18 @@ static __inline__ void set_msr(unsigned long msr)
  * 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))
+ *    CPU clock = count * (177 * (8192 / 58))
  *
- *             = count * 24999.7241
+ *             = count * 24999.7241
  *
- *   which is very close to
+ *    which is very close to
  *
- *             = count * 25000
+ *             = 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;
+ *    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
@@ -112,8 +112,8 @@ unsigned long measure_gclk(void)
         */
        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   */
+       timerp->cpmt_tcn2 = 0;          /* reset state          */
+       timerp->cpmt_tgcr |= TGCR_RST2; /* enable timer 2       */
 
        /*
         * PIT setup:
@@ -148,9 +148,9 @@ unsigned long measure_gclk(void)
        /* 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    */
+       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    */
+       timerp->cpmt_tgcr |= TGCR_STP2;         /* Stop  Timer 2        */
 
        /* re-enable external interrupts if they were on */
        set_msr (msr_val);
@@ -166,10 +166,14 @@ unsigned long measure_gclk(void)
        /* not using OSCM, using XIN, so scale appropriately */
        return (((timer2_val + 2) / 4) * (CFG_8XX_XIN/512))/8192 * 100000L;
 #else
-       return ((timer2_val + 2) / 4) * 100000L;        /* convert to Hz    */
+       return ((timer2_val + 2) / 4) * 100000L;        /* convert to Hz        */
 #endif
 }
 
+#endif
+
+#if !defined(CONFIG_TQM866M)
+
 /*
  * 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)
@@ -220,8 +224,9 @@ int get_clocks_866 (void)
        DECLARE_GLOBAL_DATA_PTR;
 
        volatile immap_t *immr = (immap_t *) CFG_IMMR;
-       char              tmp[64];
-       long              cpuclk = 0;
+       char              tmp[64];
+       long              cpuclk = 0;
+       long              sccr_reg;
 
        if (getenv_r ("cpuclk", tmp, sizeof (tmp)) > 0)
                cpuclk = simple_strtoul (tmp, NULL, 10) * 1000000;
@@ -230,11 +235,23 @@ int get_clocks_866 (void)
                cpuclk = CFG_866_CPUCLK_DEFAULT;
 
        gd->cpu_clk = init_pll_866 (cpuclk);
+#if defined(CFG_MEASURE_CPUCLK)
+       gd->cpu_clk = measure_gclk ();
+#endif
 
-       if ((immr->im_clkrst.car_sccr & SCCR_EBDF11) == 0)
+       /* 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
+       } 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);
 }
@@ -246,7 +263,7 @@ int sdram_adjust_866 (void)
        DECLARE_GLOBAL_DATA_PTR;
 
        volatile immap_t *immr = (immap_t *) CFG_IMMR;
-       long              mamr;
+       long              mamr;
 
        mamr = immr->im_memctl.memc_mamr;
        mamr &= ~MAMR_PTA_MSK;
@@ -265,12 +282,23 @@ static long init_pll_866 (long clk)
        extern void plprcr_write_866 (long);
 
        volatile immap_t *immr = (immap_t *) CFG_IMMR;
-       long              n, plprcr;
-       char              mfi, mfn, mfd, s, pdf;
-       long              step_mfi, step_mfn;
+       long              n, plprcr;
+       char              mfi, mfn, mfd, s, pdf;
+       long              step_mfi, step_mfn;
 
-       pdf = 0;
-       if (clk < 80000000) {
+       if (clk < 20000000) {
+               clk *= 2;
+               pdf = 1;
+       } else {
+               pdf = 0;
+       }
+
+       if (clk < 40000000) {
+               s = 2;
+               step_mfi = CFG_866_OSCCLK / 4;
+               mfd = 7;
+               step_mfn = CFG_866_OSCCLK / 30;
+       } else if (clk < 80000000) {
                s = 1;
                step_mfi = CFG_866_OSCCLK / 2;
                mfd = 14;
@@ -294,13 +322,14 @@ static long init_pll_866 (long clk)
 
        /* Calculate effective clk
         */
-       n = (mfi * step_mfi) + (mfn * step_mfn);
+       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_MFI_MSK | PLPRCR_DBRMO
+                       | PLPRCR_PDF_MSK))
                        | (mfn << PLPRCR_MFN_SHIFT)
                        | (mfd << PLPRCR_MFD_SHIFT)
                        | (s << PLPRCR_S_SHIFT)