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/*-
* Copyright (c) 2009 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include "cpufreq_if.h"
struct dfs_softc {
device_t dev;
int dfs4;
};
static void dfs_identify(driver_t *driver, device_t parent);
static int dfs_probe(device_t dev);
static int dfs_attach(device_t dev);
static int dfs_settings(device_t dev, struct cf_setting *sets, int *count);
static int dfs_set(device_t dev, const struct cf_setting *set);
static int dfs_get(device_t dev, struct cf_setting *set);
static int dfs_type(device_t dev, int *type);
static device_method_t dfs_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, dfs_identify),
DEVMETHOD(device_probe, dfs_probe),
DEVMETHOD(device_attach, dfs_attach),
/* cpufreq interface */
DEVMETHOD(cpufreq_drv_set, dfs_set),
DEVMETHOD(cpufreq_drv_get, dfs_get),
DEVMETHOD(cpufreq_drv_type, dfs_type),
DEVMETHOD(cpufreq_drv_settings, dfs_settings),
{0, 0}
};
static driver_t dfs_driver = {
"dfs",
dfs_methods,
sizeof(struct dfs_softc)
};
static devclass_t dfs_devclass;
DRIVER_MODULE(dfs, cpu, dfs_driver, dfs_devclass, 0, 0);
/*
* Bits of the HID1 register to enable DFS. See page 2-24 of "MPC7450
* RISC Microprocessor Family Reference Manual", rev. 5.
*/
#define HID1_DFS2 (1UL << 22)
#define HID1_DFS4 (1UL << 23)
static void
dfs_identify(driver_t *driver, device_t parent)
{
uint16_t vers;
vers = mfpvr() >> 16;
/* Check for an MPC 7447A or 7448 CPU */
switch (vers) {
case MPC7447A:
case MPC7448:
break;
default:
return;
}
/* Make sure we're not being doubly invoked. */
if (device_find_child(parent, "dfs", -1) != NULL)
return;
/*
* We attach a child for every CPU since settings need to
* be performed on every CPU in the SMP case.
*/
if (BUS_ADD_CHILD(parent, 10, "dfs", -1) == NULL)
device_printf(parent, "add dfs child failed\n");
}
static int
dfs_probe(device_t dev)
{
if (resource_disabled("dfs", 0))
return (ENXIO);
device_set_desc(dev, "Dynamic Frequency Switching");
return (0);
}
static int
dfs_attach(device_t dev)
{
struct dfs_softc *sc;
uint16_t vers;
sc = device_get_softc(dev);
sc->dev = dev;
sc->dfs4 = 0;
vers = mfpvr() >> 16;
/* The 7448 supports divide-by-four as well */
if (vers == MPC7448)
sc->dfs4 = 1;
cpufreq_register(dev);
return (0);
}
static int
dfs_settings(device_t dev, struct cf_setting *sets, int *count)
{
struct dfs_softc *sc;
int states;
sc = device_get_softc(dev);
states = sc->dfs4 ? 3 : 2;
if (sets == NULL || count == NULL)
return (EINVAL);
if (*count < states)
return (E2BIG);
/* Return a list of valid settings for this driver. */
memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * states);
sets[0].freq = 10000; sets[0].dev = dev;
sets[1].freq = 5000; sets[1].dev = dev;
if (sc->dfs4)
sets[2].freq = 2500; sets[2].dev = dev;
*count = states;
return (0);
}
static int
dfs_set(device_t dev, const struct cf_setting *set)
{
register_t hid1;
if (set == NULL)
return (EINVAL);
hid1 = mfspr(SPR_HID1);
hid1 &= ~(HID1_DFS2 | HID1_DFS4);
if (set->freq == 5000)
hid1 |= HID1_DFS2;
else if (set->freq == 2500)
hid1 |= HID1_DFS4;
/*
* Now set the HID1 register with new values. Calling sequence
* taken from page 2-26 of the MPC7450 family CPU manual.
*/
powerpc_sync();
mtspr(SPR_HID1, hid1);
powerpc_sync(); isync();
return (0);
}
static int
dfs_get(device_t dev, struct cf_setting *set)
{
struct dfs_softc *sc;
register_t hid1;
if (set == NULL)
return (EINVAL);
sc = device_get_softc(dev);
memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
hid1 = mfspr(SPR_HID1);
set->freq = 10000;
if (hid1 & HID1_DFS2)
set->freq = 5000;
else if (sc->dfs4 && (hid1 & HID1_DFS4))
set->freq = 2500;
set->dev = dev;
return (0);
}
static int
dfs_type(device_t dev, int *type)
{
if (type == NULL)
return (EINVAL);
*type = CPUFREQ_TYPE_RELATIVE;
return (0);
}
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