kernel-ark/arch/powerpc/boot/pq2.c
Scott Wood bbc6fac387 [POWERPC] bootwrapper: Add fsl_get_immr() and 8xx/pq2 clock functions.
fsl_get_immr() uses /soc/ranges to determine the immr.

mpc885_get_clock() transforms a crystal frequency into a system frequency
according to the PLL register settings.

pq2_get_clocks() does the same as the above for the PowerQUICC II,
except that it produces several different clocks.

The mpc8xx/pq2 set_clocks() functions modify common properties in
the device tree based on the given clock data.

The mpc885/pq2 fixup_clocks() functions call get_clocks(), and
pass the results to set_clocks().

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-10-03 20:36:35 -05:00

103 lines
2.4 KiB
C

/*
* PowerQUICC II 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 "pq2.h"
#include "stdio.h"
#include "io.h"
#define PQ2_SCCR (0x10c80/4) /* System Clock Configuration Register */
#define PQ2_SCMR (0x10c88/4) /* System Clock Mode Register */
static int pq2_corecnf_map[] = {
3, 2, 2, 2, 4, 4, 5, 9, 6, 11, 8, 10, 3, 12, 7, -1,
6, 5, 13, 2, 14, 4, 15, 9, 0, 11, 8, 10, 16, 12, 7, -1
};
/* Get various clocks from crystal frequency.
* Returns zero on failure and non-zero on success.
*/
int pq2_get_clocks(u32 crystal, u32 *sysfreq, u32 *corefreq,
u32 *timebase, u32 *brgfreq)
{
u32 *immr;
u32 sccr, scmr, mainclk, busclk;
int corecnf, busdf, plldf, pllmf, dfbrg;
immr = fsl_get_immr();
if (!immr) {
printf("pq2_get_clocks: Couldn't get IMMR base.\r\n");
return 0;
}
sccr = in_be32(&immr[PQ2_SCCR]);
scmr = in_be32(&immr[PQ2_SCMR]);
dfbrg = sccr & 3;
corecnf = (scmr >> 24) & 0x1f;
busdf = (scmr >> 20) & 0xf;
plldf = (scmr >> 12) & 1;
pllmf = scmr & 0xfff;
mainclk = crystal * (pllmf + 1) / (plldf + 1);
busclk = mainclk / (busdf + 1);
if (sysfreq)
*sysfreq = mainclk / 2;
if (timebase)
*timebase = busclk / 4;
if (brgfreq)
*brgfreq = mainclk / (1 << ((dfbrg + 1) * 2));
if (corefreq) {
int coremult = pq2_corecnf_map[corecnf];
if (coremult < 0)
*corefreq = mainclk / 2;
else if (coremult == 0)
return 0;
else
*corefreq = busclk * coremult / 2;
}
return 1;
}
/* Set common device tree fields based on the given clock frequencies. */
void pq2_set_clocks(u32 sysfreq, u32 corefreq, u32 timebase, u32 brgfreq)
{
void *node;
dt_fixup_cpu_clocks(corefreq, timebase, sysfreq);
node = finddevice("/soc/cpm");
if (node)
setprop(node, "clock-frequency", &sysfreq, 4);
node = finddevice("/soc/cpm/brg");
if (node)
setprop(node, "clock-frequency", &brgfreq, 4);
}
int pq2_fixup_clocks(u32 crystal)
{
u32 sysfreq, corefreq, timebase, brgfreq;
if (!pq2_get_clocks(crystal, &sysfreq, &corefreq, &timebase, &brgfreq))
return 0;
pq2_set_clocks(sysfreq, corefreq, timebase, brgfreq);
return 1;
}