83 lines
1.7 KiB
C
83 lines
1.7 KiB
C
|
/*
|
||
|
|
* 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;
|
||
|
|
}
|