cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

mpc8xx.c (1511B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * MPC8xx support functions
      4 *
      5 * Author: Scott Wood <scottwood@freescale.com>
      6 *
      7 * Copyright (c) 2007 Freescale Semiconductor, Inc.
      8 */
      9
     10#include "ops.h"
     11#include "types.h"
     12#include "fsl-soc.h"
     13#include "mpc8xx.h"
     14#include "stdio.h"
     15#include "io.h"
     16
     17#define MPC8XX_PLPRCR (0x284/4) /* PLL and Reset Control Register */
     18
     19/* Return system clock from crystal frequency */
     20u32 mpc885_get_clock(u32 crystal)
     21{
     22	u32 *immr;
     23	u32 plprcr;
     24	int mfi, mfn, mfd, pdf;
     25	u32 ret;
     26
     27	immr = fsl_get_immr();
     28	if (!immr) {
     29		printf("mpc885_get_clock: Couldn't get IMMR base.\r\n");
     30		return 0;
     31	}
     32
     33	plprcr = in_be32(&immr[MPC8XX_PLPRCR]);
     34
     35	mfi = (plprcr >> 16) & 15;
     36	if (mfi < 5) {
     37		printf("Warning: PLPRCR[MFI] value of %d out-of-bounds\r\n",
     38		       mfi);
     39		mfi = 5;
     40	}
     41
     42	pdf = (plprcr >> 1) & 0xf;
     43	mfd = (plprcr >> 22) & 0x1f;
     44	mfn = (plprcr >> 27) & 0x1f;
     45
     46	ret = crystal * mfi;
     47
     48	if (mfn != 0)
     49		ret += crystal * mfn / (mfd + 1);
     50
     51	return ret / (pdf + 1);
     52}
     53
     54/* Set common device tree fields based on the given clock frequencies. */
     55void mpc8xx_set_clocks(u32 sysclk)
     56{
     57	void *node;
     58
     59	dt_fixup_cpu_clocks(sysclk, sysclk / 16, sysclk);
     60
     61	node = finddevice("/soc/cpm");
     62	if (node)
     63		setprop(node, "clock-frequency", &sysclk, 4);
     64
     65	node = finddevice("/soc/cpm/brg");
     66	if (node)
     67		setprop(node, "clock-frequency", &sysclk, 4);
     68}
     69
     70int mpc885_fixup_clocks(u32 crystal)
     71{
     72	u32 sysclk = mpc885_get_clock(crystal);
     73	if (!sysclk)
     74		return 0;
     75
     76	mpc8xx_set_clocks(sysclk);
     77	return 1;
     78}