+++ /dev/null
-/*
- * 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.
- *
- * Theoritical 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 Moduration.
- *
- * 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 <asm/processor-cyrix.h>
-#include <asm/errno.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 belows support 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 belows support 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 = 0;
-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, },
-};
-
-/**
- * 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 ((current_cpu_data.x86_vendor != X86_VENDOR_NSC) &&
- (current_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 */
- pci_write_config_byte(gx_params->cs55x0, PCI_IRQTC, 4); /* typical 2 to 4ms */
- pci_write_config_byte(gx_params->cs55x0, PCI_VIDTC, 100);/* typical 50 to 100ms */
- pci_write_config_byte(gx_params->cs55x0, 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 percent speed.\n");
- }
-
- pci_write_config_byte(gx_params->cs55x0, PCI_MODOFF, gx_params->off_duration);
- pci_write_config_byte(gx_params->cs55x0, PCI_MODON, gx_params->on_duration);
-
- pci_write_config_byte(gx_params->cs55x0, 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->governor = CPUFREQ_DEFAULT_GOVERNOR;
- 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 */
- if ((gx_pci = gx_detect_chipset()) == 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));
-
- if ((ret = cpufreq_register_driver(&gx_suspmod_driver))) {
- 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);
-
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