520 lines
15 KiB
C
520 lines
15 KiB
C
/*
|
|
* Cyrix MediaGX and NatSemi Geode Suspend Modulation
|
|
* (C) 2002 Zwane Mwaikambo <zwane@commfireservices.com>
|
|
* (C) 2002 Hiroshi Miura <miura@da-cha.org>
|
|
* All Rights Reserved
|
|
*
|
|
* 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
|
|
*
|
|
* The author(s) of this software shall not be held liable for damages
|
|
* of any nature resulting due to the use of this software. This
|
|
* software is provided AS-IS with no warranties.
|
|
*
|
|
* Theoretical note:
|
|
*
|
|
* (see Geode(tm) CS5530 manual (rev.4.1) page.56)
|
|
*
|
|
* CPU frequency control on NatSemi Geode GX1/GXLV processor and CS55x0
|
|
* are based on Suspend Modulation.
|
|
*
|
|
* Suspend Modulation works by asserting and de-asserting the SUSP# pin
|
|
* to CPU(GX1/GXLV) for configurable durations. When asserting SUSP#
|
|
* the CPU enters an idle state. GX1 stops its core clock when SUSP# is
|
|
* asserted then power consumption is reduced.
|
|
*
|
|
* Suspend Modulation's OFF/ON duration are configurable
|
|
* with 'Suspend Modulation OFF Count Register'
|
|
* and 'Suspend Modulation ON Count Register'.
|
|
* These registers are 8bit counters that represent the number of
|
|
* 32us intervals which the SUSP# pin is asserted(ON)/de-asserted(OFF)
|
|
* to the processor.
|
|
*
|
|
* These counters define a ratio which is the effective frequency
|
|
* of operation of the system.
|
|
*
|
|
* OFF Count
|
|
* F_eff = Fgx * ----------------------
|
|
* OFF Count + ON Count
|
|
*
|
|
* 0 <= On Count, Off Count <= 255
|
|
*
|
|
* From these limits, we can get register values
|
|
*
|
|
* off_duration + on_duration <= MAX_DURATION
|
|
* on_duration = off_duration * (stock_freq - freq) / freq
|
|
*
|
|
* off_duration = (freq * DURATION) / stock_freq
|
|
* on_duration = DURATION - off_duration
|
|
*
|
|
*
|
|
*---------------------------------------------------------------------------
|
|
*
|
|
* ChangeLog:
|
|
* Dec. 12, 2003 Hiroshi Miura <miura@da-cha.org>
|
|
* - fix on/off register mistake
|
|
* - fix cpu_khz calc when it stops cpu modulation.
|
|
*
|
|
* Dec. 11, 2002 Hiroshi Miura <miura@da-cha.org>
|
|
* - rewrite for Cyrix MediaGX Cx5510/5520 and
|
|
* NatSemi Geode Cs5530(A).
|
|
*
|
|
* Jul. ??, 2002 Zwane Mwaikambo <zwane@commfireservices.com>
|
|
* - cs5530_mod patch for 2.4.19-rc1.
|
|
*
|
|
*---------------------------------------------------------------------------
|
|
*
|
|
* Todo
|
|
* Test on machines with 5510, 5530, 5530A
|
|
*/
|
|
|
|
/************************************************************************
|
|
* Suspend Modulation - Definitions *
|
|
************************************************************************/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/cpufreq.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/errno.h>
|
|
|
|
#include <asm/processor-cyrix.h>
|
|
|
|
/* PCI config registers, all at F0 */
|
|
#define PCI_PMER1 0x80 /* power management enable register 1 */
|
|
#define PCI_PMER2 0x81 /* power management enable register 2 */
|
|
#define PCI_PMER3 0x82 /* power management enable register 3 */
|
|
#define PCI_IRQTC 0x8c /* irq speedup timer counter register:typical 2 to 4ms */
|
|
#define PCI_VIDTC 0x8d /* video speedup timer counter register: typical 50 to 100ms */
|
|
#define PCI_MODOFF 0x94 /* suspend modulation OFF counter register, 1 = 32us */
|
|
#define PCI_MODON 0x95 /* suspend modulation ON counter register */
|
|
#define PCI_SUSCFG 0x96 /* suspend configuration register */
|
|
|
|
/* PMER1 bits */
|
|
#define GPM (1<<0) /* global power management */
|
|
#define GIT (1<<1) /* globally enable PM device idle timers */
|
|
#define GTR (1<<2) /* globally enable IO traps */
|
|
#define IRQ_SPDUP (1<<3) /* disable clock throttle during interrupt handling */
|
|
#define VID_SPDUP (1<<4) /* disable clock throttle during vga video handling */
|
|
|
|
/* SUSCFG bits */
|
|
#define SUSMOD (1<<0) /* enable/disable suspend modulation */
|
|
/* the below is supported only with cs5530 (after rev.1.2)/cs5530A */
|
|
#define SMISPDUP (1<<1) /* select how SMI re-enable suspend modulation: */
|
|
/* IRQTC timer or read SMI speedup disable reg.(F1BAR[08-09h]) */
|
|
#define SUSCFG (1<<2) /* enable powering down a GXLV processor. "Special 3Volt Suspend" mode */
|
|
/* the below is supported only with cs5530A */
|
|
#define PWRSVE_ISA (1<<3) /* stop ISA clock */
|
|
#define PWRSVE (1<<4) /* active idle */
|
|
|
|
struct gxfreq_params {
|
|
u8 on_duration;
|
|
u8 off_duration;
|
|
u8 pci_suscfg;
|
|
u8 pci_pmer1;
|
|
u8 pci_pmer2;
|
|
struct pci_dev *cs55x0;
|
|
};
|
|
|
|
static struct gxfreq_params *gx_params;
|
|
static int stock_freq;
|
|
|
|
/* PCI bus clock - defaults to 30.000 if cpu_khz is not available */
|
|
static int pci_busclk;
|
|
module_param(pci_busclk, int, 0444);
|
|
|
|
/* maximum duration for which the cpu may be suspended
|
|
* (32us * MAX_DURATION). If no parameter is given, this defaults
|
|
* to 255.
|
|
* Note that this leads to a maximum of 8 ms(!) where the CPU clock
|
|
* is suspended -- processing power is just 0.39% of what it used to be,
|
|
* though. 781.25 kHz(!) for a 200 MHz processor -- wow. */
|
|
static int max_duration = 255;
|
|
module_param(max_duration, int, 0444);
|
|
|
|
/* For the default policy, we want at least some processing power
|
|
* - let's say 5%. (min = maxfreq / POLICY_MIN_DIV)
|
|
*/
|
|
#define POLICY_MIN_DIV 20
|
|
|
|
|
|
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
|
|
"gx-suspmod", msg)
|
|
|
|
/**
|
|
* we can detect a core multipiler from dir0_lsb
|
|
* from GX1 datasheet p.56,
|
|
* MULT[3:0]:
|
|
* 0000 = SYSCLK multiplied by 4 (test only)
|
|
* 0001 = SYSCLK multiplied by 10
|
|
* 0010 = SYSCLK multiplied by 4
|
|
* 0011 = SYSCLK multiplied by 6
|
|
* 0100 = SYSCLK multiplied by 9
|
|
* 0101 = SYSCLK multiplied by 5
|
|
* 0110 = SYSCLK multiplied by 7
|
|
* 0111 = SYSCLK multiplied by 8
|
|
* of 33.3MHz
|
|
**/
|
|
static int gx_freq_mult[16] = {
|
|
4, 10, 4, 6, 9, 5, 7, 8,
|
|
0, 0, 0, 0, 0, 0, 0, 0
|
|
};
|
|
|
|
|
|
/****************************************************************
|
|
* Low Level chipset interface *
|
|
****************************************************************/
|
|
static struct pci_device_id gx_chipset_tbl[] __initdata = {
|
|
{ PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY,
|
|
PCI_ANY_ID, PCI_ANY_ID },
|
|
{ PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5520,
|
|
PCI_ANY_ID, PCI_ANY_ID },
|
|
{ PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5510,
|
|
PCI_ANY_ID, PCI_ANY_ID },
|
|
{ 0, },
|
|
};
|
|
|
|
static void gx_write_byte(int reg, int value)
|
|
{
|
|
pci_write_config_byte(gx_params->cs55x0, reg, value);
|
|
}
|
|
|
|
/**
|
|
* gx_detect_chipset:
|
|
*
|
|
**/
|
|
static __init struct pci_dev *gx_detect_chipset(void)
|
|
{
|
|
struct pci_dev *gx_pci = NULL;
|
|
|
|
/* check if CPU is a MediaGX or a Geode. */
|
|
if ((boot_cpu_data.x86_vendor != X86_VENDOR_NSC) &&
|
|
(boot_cpu_data.x86_vendor != X86_VENDOR_CYRIX)) {
|
|
dprintk("error: no MediaGX/Geode processor found!\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* detect which companion chip is used */
|
|
while ((gx_pci = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, gx_pci)) != NULL) {
|
|
if ((pci_match_id(gx_chipset_tbl, gx_pci)) != NULL)
|
|
return gx_pci;
|
|
}
|
|
|
|
dprintk("error: no supported chipset found!\n");
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* gx_get_cpuspeed:
|
|
*
|
|
* Finds out at which efficient frequency the Cyrix MediaGX/NatSemi
|
|
* Geode CPU runs.
|
|
*/
|
|
static unsigned int gx_get_cpuspeed(unsigned int cpu)
|
|
{
|
|
if ((gx_params->pci_suscfg & SUSMOD) == 0)
|
|
return stock_freq;
|
|
|
|
return (stock_freq * gx_params->off_duration)
|
|
/ (gx_params->on_duration + gx_params->off_duration);
|
|
}
|
|
|
|
/**
|
|
* gx_validate_speed:
|
|
* determine current cpu speed
|
|
*
|
|
**/
|
|
|
|
static unsigned int gx_validate_speed(unsigned int khz, u8 *on_duration,
|
|
u8 *off_duration)
|
|
{
|
|
unsigned int i;
|
|
u8 tmp_on, tmp_off;
|
|
int old_tmp_freq = stock_freq;
|
|
int tmp_freq;
|
|
|
|
*off_duration = 1;
|
|
*on_duration = 0;
|
|
|
|
for (i = max_duration; i > 0; i--) {
|
|
tmp_off = ((khz * i) / stock_freq) & 0xff;
|
|
tmp_on = i - tmp_off;
|
|
tmp_freq = (stock_freq * tmp_off) / i;
|
|
/* if this relation is closer to khz, use this. If it's equal,
|
|
* prefer it, too - lower latency */
|
|
if (abs(tmp_freq - khz) <= abs(old_tmp_freq - khz)) {
|
|
*on_duration = tmp_on;
|
|
*off_duration = tmp_off;
|
|
old_tmp_freq = tmp_freq;
|
|
}
|
|
}
|
|
|
|
return old_tmp_freq;
|
|
}
|
|
|
|
|
|
/**
|
|
* gx_set_cpuspeed:
|
|
* set cpu speed in khz.
|
|
**/
|
|
|
|
static void gx_set_cpuspeed(unsigned int khz)
|
|
{
|
|
u8 suscfg, pmer1;
|
|
unsigned int new_khz;
|
|
unsigned long flags;
|
|
struct cpufreq_freqs freqs;
|
|
|
|
freqs.cpu = 0;
|
|
freqs.old = gx_get_cpuspeed(0);
|
|
|
|
new_khz = gx_validate_speed(khz, &gx_params->on_duration,
|
|
&gx_params->off_duration);
|
|
|
|
freqs.new = new_khz;
|
|
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
|
|
local_irq_save(flags);
|
|
|
|
|
|
|
|
if (new_khz != stock_freq) {
|
|
/* if new khz == 100% of CPU speed, it is special case */
|
|
switch (gx_params->cs55x0->device) {
|
|
case PCI_DEVICE_ID_CYRIX_5530_LEGACY:
|
|
pmer1 = gx_params->pci_pmer1 | IRQ_SPDUP | VID_SPDUP;
|
|
/* FIXME: need to test other values -- Zwane,Miura */
|
|
/* typical 2 to 4ms */
|
|
gx_write_byte(PCI_IRQTC, 4);
|
|
/* typical 50 to 100ms */
|
|
gx_write_byte(PCI_VIDTC, 100);
|
|
gx_write_byte(PCI_PMER1, pmer1);
|
|
|
|
if (gx_params->cs55x0->revision < 0x10) {
|
|
/* CS5530(rev 1.2, 1.3) */
|
|
suscfg = gx_params->pci_suscfg|SUSMOD;
|
|
} else {
|
|
/* CS5530A,B.. */
|
|
suscfg = gx_params->pci_suscfg|SUSMOD|PWRSVE;
|
|
}
|
|
break;
|
|
case PCI_DEVICE_ID_CYRIX_5520:
|
|
case PCI_DEVICE_ID_CYRIX_5510:
|
|
suscfg = gx_params->pci_suscfg | SUSMOD;
|
|
break;
|
|
default:
|
|
local_irq_restore(flags);
|
|
dprintk("fatal: try to set unknown chipset.\n");
|
|
return;
|
|
}
|
|
} else {
|
|
suscfg = gx_params->pci_suscfg & ~(SUSMOD);
|
|
gx_params->off_duration = 0;
|
|
gx_params->on_duration = 0;
|
|
dprintk("suspend modulation disabled: cpu runs 100%% speed.\n");
|
|
}
|
|
|
|
gx_write_byte(PCI_MODOFF, gx_params->off_duration);
|
|
gx_write_byte(PCI_MODON, gx_params->on_duration);
|
|
|
|
gx_write_byte(PCI_SUSCFG, suscfg);
|
|
pci_read_config_byte(gx_params->cs55x0, PCI_SUSCFG, &suscfg);
|
|
|
|
local_irq_restore(flags);
|
|
|
|
gx_params->pci_suscfg = suscfg;
|
|
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
|
|
|
|
dprintk("suspend modulation w/ duration of ON:%d us, OFF:%d us\n",
|
|
gx_params->on_duration * 32, gx_params->off_duration * 32);
|
|
dprintk("suspend modulation w/ clock speed: %d kHz.\n", freqs.new);
|
|
}
|
|
|
|
/****************************************************************
|
|
* High level functions *
|
|
****************************************************************/
|
|
|
|
/*
|
|
* cpufreq_gx_verify: test if frequency range is valid
|
|
*
|
|
* This function checks if a given frequency range in kHz is valid
|
|
* for the hardware supported by the driver.
|
|
*/
|
|
|
|
static int cpufreq_gx_verify(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int tmp_freq = 0;
|
|
u8 tmp1, tmp2;
|
|
|
|
if (!stock_freq || !policy)
|
|
return -EINVAL;
|
|
|
|
policy->cpu = 0;
|
|
cpufreq_verify_within_limits(policy, (stock_freq / max_duration),
|
|
stock_freq);
|
|
|
|
/* it needs to be assured that at least one supported frequency is
|
|
* within policy->min and policy->max. If it is not, policy->max
|
|
* needs to be increased until one freuqency is supported.
|
|
* policy->min may not be decreased, though. This way we guarantee a
|
|
* specific processing capacity.
|
|
*/
|
|
tmp_freq = gx_validate_speed(policy->min, &tmp1, &tmp2);
|
|
if (tmp_freq < policy->min)
|
|
tmp_freq += stock_freq / max_duration;
|
|
policy->min = tmp_freq;
|
|
if (policy->min > policy->max)
|
|
policy->max = tmp_freq;
|
|
tmp_freq = gx_validate_speed(policy->max, &tmp1, &tmp2);
|
|
if (tmp_freq > policy->max)
|
|
tmp_freq -= stock_freq / max_duration;
|
|
policy->max = tmp_freq;
|
|
if (policy->max < policy->min)
|
|
policy->max = policy->min;
|
|
cpufreq_verify_within_limits(policy, (stock_freq / max_duration),
|
|
stock_freq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* cpufreq_gx_target:
|
|
*
|
|
*/
|
|
static int cpufreq_gx_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
u8 tmp1, tmp2;
|
|
unsigned int tmp_freq;
|
|
|
|
if (!stock_freq || !policy)
|
|
return -EINVAL;
|
|
|
|
policy->cpu = 0;
|
|
|
|
tmp_freq = gx_validate_speed(target_freq, &tmp1, &tmp2);
|
|
while (tmp_freq < policy->min) {
|
|
tmp_freq += stock_freq / max_duration;
|
|
tmp_freq = gx_validate_speed(tmp_freq, &tmp1, &tmp2);
|
|
}
|
|
while (tmp_freq > policy->max) {
|
|
tmp_freq -= stock_freq / max_duration;
|
|
tmp_freq = gx_validate_speed(tmp_freq, &tmp1, &tmp2);
|
|
}
|
|
|
|
gx_set_cpuspeed(tmp_freq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int maxfreq, curfreq;
|
|
|
|
if (!policy || policy->cpu != 0)
|
|
return -ENODEV;
|
|
|
|
/* determine maximum frequency */
|
|
if (pci_busclk)
|
|
maxfreq = pci_busclk * gx_freq_mult[getCx86(CX86_DIR1) & 0x0f];
|
|
else if (cpu_khz)
|
|
maxfreq = cpu_khz;
|
|
else
|
|
maxfreq = 30000 * gx_freq_mult[getCx86(CX86_DIR1) & 0x0f];
|
|
|
|
stock_freq = maxfreq;
|
|
curfreq = gx_get_cpuspeed(0);
|
|
|
|
dprintk("cpu max frequency is %d.\n", maxfreq);
|
|
dprintk("cpu current frequency is %dkHz.\n", curfreq);
|
|
|
|
/* setup basic struct for cpufreq API */
|
|
policy->cpu = 0;
|
|
|
|
if (max_duration < POLICY_MIN_DIV)
|
|
policy->min = maxfreq / max_duration;
|
|
else
|
|
policy->min = maxfreq / POLICY_MIN_DIV;
|
|
policy->max = maxfreq;
|
|
policy->cur = curfreq;
|
|
policy->cpuinfo.min_freq = maxfreq / max_duration;
|
|
policy->cpuinfo.max_freq = maxfreq;
|
|
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* cpufreq_gx_init:
|
|
* MediaGX/Geode GX initialize cpufreq driver
|
|
*/
|
|
static struct cpufreq_driver gx_suspmod_driver = {
|
|
.get = gx_get_cpuspeed,
|
|
.verify = cpufreq_gx_verify,
|
|
.target = cpufreq_gx_target,
|
|
.init = cpufreq_gx_cpu_init,
|
|
.name = "gx-suspmod",
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init cpufreq_gx_init(void)
|
|
{
|
|
int ret;
|
|
struct gxfreq_params *params;
|
|
struct pci_dev *gx_pci;
|
|
|
|
/* Test if we have the right hardware */
|
|
gx_pci = gx_detect_chipset();
|
|
if (gx_pci == NULL)
|
|
return -ENODEV;
|
|
|
|
/* check whether module parameters are sane */
|
|
if (max_duration > 0xff)
|
|
max_duration = 0xff;
|
|
|
|
dprintk("geode suspend modulation available.\n");
|
|
|
|
params = kzalloc(sizeof(struct gxfreq_params), GFP_KERNEL);
|
|
if (params == NULL)
|
|
return -ENOMEM;
|
|
|
|
params->cs55x0 = gx_pci;
|
|
gx_params = params;
|
|
|
|
/* keep cs55x0 configurations */
|
|
pci_read_config_byte(params->cs55x0, PCI_SUSCFG, &(params->pci_suscfg));
|
|
pci_read_config_byte(params->cs55x0, PCI_PMER1, &(params->pci_pmer1));
|
|
pci_read_config_byte(params->cs55x0, PCI_PMER2, &(params->pci_pmer2));
|
|
pci_read_config_byte(params->cs55x0, PCI_MODON, &(params->on_duration));
|
|
pci_read_config_byte(params->cs55x0, PCI_MODOFF,
|
|
&(params->off_duration));
|
|
|
|
ret = cpufreq_register_driver(&gx_suspmod_driver);
|
|
if (ret) {
|
|
kfree(params);
|
|
return ret; /* register error! */
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit cpufreq_gx_exit(void)
|
|
{
|
|
cpufreq_unregister_driver(&gx_suspmod_driver);
|
|
pci_dev_put(gx_params->cs55x0);
|
|
kfree(gx_params);
|
|
}
|
|
|
|
MODULE_AUTHOR("Hiroshi Miura <miura@da-cha.org>");
|
|
MODULE_DESCRIPTION("Cpufreq driver for Cyrix MediaGX and NatSemi Geode");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(cpufreq_gx_init);
|
|
module_exit(cpufreq_gx_exit);
|
|
|