/* * MPC8xx support functions * * Author: Scott Wood <scottwood@freescale.com> * * Copyright (c) 2007 Freescale Semiconductor, Inc. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. */ #include "ops.h" #include "types.h" #include "fsl-soc.h" #include "mpc8xx.h" #include "stdio.h" #include "io.h" #define MPC8XX_PLPRCR (0x284/4) /* PLL and Reset Control Register */ /* Return system clock from crystal frequency */ u32 mpc885_get_clock(u32 crystal) { u32 *immr; u32 plprcr; int mfi, mfn, mfd, pdf, div; u32 ret; immr = fsl_get_immr(); if (!immr) { printf("mpc885_get_clock: Couldn't get IMMR base.\r\n"); return 0; } plprcr = in_be32(&immr[MPC8XX_PLPRCR]); mfi = (plprcr >> 16) & 15; if (mfi < 5) { printf("Warning: PLPRCR[MFI] value of %d out-of-bounds\r\n", mfi); mfi = 5; } pdf = (plprcr >> 1) & 0xf; div = (plprcr >> 20) & 3; mfd = (plprcr >> 22) & 0x1f; mfn = (plprcr >> 27) & 0x1f; ret = crystal * mfi; if (mfn != 0) ret += crystal * mfn / (mfd + 1); return ret / (pdf + 1); } /* Set common device tree fields based on the given clock frequencies. */ void mpc8xx_set_clocks(u32 sysclk) { void *node; dt_fixup_cpu_clocks(sysclk, sysclk / 16, sysclk); node = finddevice("/soc/cpm"); if (node) setprop(node, "clock-frequency", &sysclk, 4); node = finddevice("/soc/cpm/brg"); if (node) setprop(node, "clock-frequency", &sysclk, 4); } int mpc885_fixup_clocks(u32 crystal) { u32 sysclk = mpc885_get_clock(crystal); if (!sysclk) return 0; mpc8xx_set_clocks(sysclk); return 1; }