diff options
Diffstat (limited to 'cpu/mpc8xx/speed.c')
| -rw-r--r-- | cpu/mpc8xx/speed.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/cpu/mpc8xx/speed.c b/cpu/mpc8xx/speed.c index 3815537..8583eef 100644 --- a/cpu/mpc8xx/speed.c +++ b/cpu/mpc8xx/speed.c @@ -25,6 +25,8 @@ #include <mpc8xx.h> #include <asm/processor.h> +#ifndef CONFIG_TQM866M + #define PITC_SHIFT 16 #define PITR_SHIFT 16 /* pitc values to time for 58/8192 seconds (about 70.8 milliseconds) */ @@ -203,4 +205,117 @@ int get_clocks (void) return (0); } +#else /* CONFIG_MPC866_et_al */ + +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 CFG_866_CPUCLK_DEFAULT (if 'cpuclk' + * contains invalid value). + * This functions requires an MPC866 series CPU. + */ +int get_clocks_866 (void) +{ + DECLARE_GLOBAL_DATA_PTR; + + volatile immap_t *immr = (immap_t *) CFG_IMMR; + char tmp[64]; + long cpuclk = 0; + + if (getenv_r ("cpuclk", tmp, sizeof (tmp)) > 0) + cpuclk = simple_strtoul (tmp, NULL, 10) * 1000000; + + if ((CFG_866_CPUCLK_MIN > cpuclk) || (CFG_866_CPUCLK_MAX < cpuclk)) + cpuclk = CFG_866_CPUCLK_DEFAULT; + + gd->cpu_clk = init_pll_866 (cpuclk); + + if ((immr->im_clkrst.car_sccr & SCCR_EBDF11) == 0) + gd->bus_clk = gd->cpu_clk; + else + gd->bus_clk = gd->cpu_clk / 2; + + return (0); +} + +/* Adjust sdram refresh rate to actual CPU clock. + */ +int sdram_adjust_866 (void) +{ + DECLARE_GLOBAL_DATA_PTR; + + volatile immap_t *immr = (immap_t *) CFG_IMMR; + long mamr; + + mamr = immr->im_memctl.memc_mamr; + mamr &= ~MAMR_PTA_MSK; + mamr |= ((gd->cpu_clk / CFG_866_PTA_PER_CLK) << MAMR_PTA_SHIFT); + immr->im_memctl.memc_mamr = mamr; + + return (0); +} + +/* Configure PLL for MPC866/859 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 *) CFG_IMMR; + long n, plprcr; + char mfi, mfn, mfd, s, pdf; + long step_mfi, step_mfn; + + pdf = 0; + if (clk < 80000000) { + s = 1; + step_mfi = CFG_866_OSCCLK / 2; + mfd = 14; + step_mfn = CFG_866_OSCCLK / 30; + } else { + s = 0; + step_mfi = CFG_866_OSCCLK; + mfd = 29; + step_mfn = CFG_866_OSCCLK / 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); + + 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)) + | (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_MPC866_et_al */ + /* ------------------------------------------------------------------------- */ |