summaryrefslogtreecommitdiff
path: root/cpu/mpc8xx/speed.c
diff options
context:
space:
mode:
authorwdenk <wdenk>2004-01-24 20:25:54 +0000
committerwdenk <wdenk>2004-01-24 20:25:54 +0000
commitc178d3da6f1ac765cd880530a0672540b415a01c (patch)
tree67e3b8e9a791d2ec97798239b5abba15e0cb5aaf /cpu/mpc8xx/speed.c
parentef978730dcb3e7e398fe9b57633f3f67260c1bbc (diff)
downloadu-boot-imx-c178d3da6f1ac765cd880530a0672540b415a01c.zip
u-boot-imx-c178d3da6f1ac765cd880530a0672540b415a01c.tar.gz
u-boot-imx-c178d3da6f1ac765cd880530a0672540b415a01c.tar.bz2
* Add variable CPU clock for MPC859/866 systems (so far only TQM866M):
see doc/README.MPC866 for details; implement workaround for "SIU4" and "SIU9" silicon bugs on MPC866; calculate CPU clock frequency from PLL register values. * Add support for 128 MB RAM on TQM8xxL/M modules
Diffstat (limited to 'cpu/mpc8xx/speed.c')
-rw-r--r--cpu/mpc8xx/speed.c115
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 */
+
/* ------------------------------------------------------------------------- */