/* $Id: bbc_envctrl.c,v 1.4 2001/04/06 16:48:08 davem Exp $
* bbc_envctrl.c: UltraSPARC-III environment control driver.
*
* Copyright (C) 2001 David S. Miller (davem@redhat.com)
*/
#define __KERNEL_SYSCALLS__
static int errno;
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <asm/oplib.h>
#include <asm/ebus.h>
#include "bbc_i2c.h"
#include "max1617.h"
#undef ENVCTRL_TRACE
/* WARNING: Making changes to this driver is very dangerous.
* If you misprogram the sensor chips they can
* cut the power on you instantly.
*/
/* Two temperature sensors exist in the SunBLADE-1000 enclosure.
* Both are implemented using max1617 i2c devices. Each max1617
* monitors 2 temperatures, one for one of the cpu dies and the other
* for the ambient temperature.
*
* The max1617 is capable of being programmed with power-off
* temperature values, one low limit and one high limit. These
* can be controlled independently for the cpu or ambient temperature.
* If a limit is violated, the power is simply shut off. The frequency
* with which the max1617 does temperature sampling can be controlled
* as well.
*
* Three fans exist inside the machine, all three are controlled with
* an i2c digital to analog converter. There is a fan directed at the
* two processor slots, another for the rest of the enclosure, and the
* third is for the power supply. The first two fans may be speed
* controlled by changing the voltage fed to them. The third fan may
* only be completely off or on. The third fan is meant to only be
* disabled/enabled when entering/exiting the lowest power-saving
* mode of the machine.
*
* An environmental control kernel thread periodically monitors all
* temperature sensors. Based upon the samples it will adjust the
* fan speeds to try and keep the system within a certain temperature
* range (the goal being to make the fans as quiet as possible without
* allowing the system to get too hot).
*
* If the temperature begins to rise/fall outside of the acceptable
* operating range, a periodic warning will be sent to the kernel log.
* The fans will be put on full blast to attempt to deal with this
* situation. After exceeding the acceptable operating range by a
* certain threshold, the kernel thread will shut down the system.
* Here, the thread is attempting to shut the machine down cleanly
* before the hardware based power-off event is triggered.
*/
/* These settings are in Celsius. We use these defaults only
* if we cannot interrogate the cpu-fru SEEPROM.
*/
struct temp_limits {
s8 high_pwroff, high_shutdown, high_warn;
s8 low_warn, low_shutdown, low_pwroff;
};
static struct temp_limits cpu_temp_limits[2] = {
{ 100, 85, 80, 5, -5, -10 },
{ 100, 85, 80, 5, -5, -10 },
};
static struct temp_limits amb_temp_limits[2] = {
{ 65, 55, 40, 5, -5, -10 },
{ 65, 55, 40, 5, -5, -10 },
};
enum fan_action { FAN_SLOWER, FAN_SAME, FAN_FASTER, FAN_FULLBLAST, FAN_STATE_MAX };
struct bbc_cpu_temperature {
struct bbc_cpu_temperature *next;
struct bbc_i2c_client *client;
int index;
/* Current readings, and history. */
s8 curr_cpu_temp;
s8 curr_amb_temp;
s8 prev_cpu_temp;
s8 prev_amb_temp;
s8 avg_cpu_temp;
s8 avg_amb_temp;
int sample_tick;
enum fan_action fan_todo[2];
#define FAN_AMBIENT 0
#define FAN_CPU 1
};
struct bbc_cpu_temperature *all_bbc_temps;
struct bbc_fan_control {
struct bbc_fan_control *next;
struct bbc_i2c_client *client;
int index;
int psupply_fan_on;
int cpu_fan_speed;
int system_fan_speed;
};
struct bbc_fan_control *all_bbc_fans;
#define CPU_FAN_REG 0xf0
#define SYS_FAN_REG 0xf2
#define PSUPPLY_FAN_REG 0xf4
#define FAN_SPEED_MIN 0x0c
#define FAN_SPEED_MAX 0x3f
#define PSUPPLY_FAN_ON 0x1f
#define PSUPPLY_FAN_OFF 0x00
static void set_fan_speeds(struct bbc_fan_control *fp)
{
/* Put temperatures into range so we don't mis-program
* the hardware.
*/
if (fp->cpu_fan_speed < FAN_SPEED_MIN)
fp->cpu_fan_speed = FAN_SPEED_MIN;
if (fp->cpu_fan_speed > FAN_SPEED_MAX)
fp->cpu_fan_speed = FAN_SPEED_MAX;
if (fp->system_fan_speed < FAN_SPEED_MIN)
fp->system_fan_speed = FAN_SPEED_MIN;
if (fp->system_fan_speed > FAN_SPEED_MAX)
fp->system_fan_speed = FAN_SPEED_MAX;
#ifdef ENVCTRL_TRACE
printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
fp->index,
fp->cpu_fan_speed, fp->system_fan_speed);
#endif
bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG);
bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG);
bbc_i2c_writeb(fp->client,
(fp->psupply_fan_on ?
PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF),
PSUPPLY_FAN_REG);
}
static void get_current_temps(struct bbc_cpu_temperature *tp)
{
tp->prev_amb_temp = tp->curr_amb_temp;
bbc_i2c_readb(tp->client,
(unsigned char *) &tp->curr_amb_temp,
MAX1617_AMB_TEMP);
tp->prev_cpu_temp = tp->curr_cpu_temp;
bbc_i2c_readb(tp->client,
(unsigned char *) &tp->curr_cpu_temp,
MAX1617_CPU_TEMP);
#ifdef ENVCTRL_TRACE
printk("temp%d: cpu(%d C) amb(%d C)\n",
tp->index,
(int) tp->curr_cpu_temp, (int) tp->curr_amb_temp);
#endif
}
static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
{
static int shutting_down = 0;
static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
char *type = "???";
s8 val = -1;
if (shutting_down != 0)
return;
if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
type = "ambient";
val = tp->curr_amb_temp;
} else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
type = "CPU";
val = tp->curr_cpu_temp;
}
printk(KERN_CRIT "temp%d: Outside of safe %s "
"operating temperature, %d C.\n",
tp->index, type, val);
printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
shutting_down = 1;
if (execve("/sbin/shutdown", argv, envp) < 0)
printk(KERN_CRIT "envctrl: shutdown execution failed\n");
}
#define WARN_INTERVAL (30 * HZ)
static void analyze_ambient_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
{
int ret = 0;
if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
if (tp->curr_amb_temp >=
amb_temp_limits[tp->index].high_warn) {
printk(KERN_WARNING "temp%d: "
"Above safe ambient operating temperature, %d C.\n",
tp->index, (int) tp->curr_amb_temp);
ret = 1;
} else if (tp->curr_amb_temp <
amb_temp_limits[tp->index].low_warn) {
printk(KERN_WARNING "temp%d: "
"Below safe ambient operating temperature, %d C.\n",
tp->index, (int) tp->curr_amb_temp);
ret = 1;
}
if (ret)
*last_warn = jiffies;
} else if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_warn ||
tp->curr_amb_temp < amb_temp_limits[tp->index].low_warn)
ret = 1;
/* Now check the shutdown limits. */
if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
do_envctrl_shutdown(tp);
ret = 1;
}
if (ret) {
tp->fan_todo[FAN_AMBIENT] = FAN_FULLBLAST;
} else if ((tick & (8 - 1)) == 0) {
s8 amb_goal_hi = amb_temp_limits[tp->index].high_warn - 10;
s8 amb_goal_lo;
amb_goal_lo = amb_goal_hi - 3;
/* We do not try to avoid 'too cold' events. Basically we
* only try to deal with over-heating and fan noise reduction.
*/
if (tp->avg_amb_temp < amb_goal_hi) {
if (tp->avg_amb_temp >= amb_goal_lo)
tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
else
tp->fan_todo[FAN_AMBIENT] = FAN_SLOWER;
} else {
tp->fan_todo[FAN_AMBIENT] = FAN_FASTER;
}
} else {
tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
}
}
static void analyze_cpu_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
{
int ret = 0;
if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
if (tp->curr_cpu_temp >=
cpu_temp_limits[tp->index].high_warn) {
printk(KERN_WARNING "temp%d: "
"Above safe CPU operating temperature, %d C.\n",
tp->index, (int) tp->curr_cpu_temp);
ret = 1;
} else if (tp->curr_cpu_temp <
cpu_temp_limits[tp->index].low_warn) {
printk(KERN_WARNING "temp%d: "
"Below safe CPU operating temperature, %d C.\n",
tp->index, (int) tp->curr_cpu_temp);
ret = 1;
}
if (ret)
*last_warn = jiffies;
} else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_warn ||
tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_warn)
ret = 1;
/* Now check the shutdown limits. */
if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
do_envctrl_shutdown(tp);
ret = 1;
}
if (ret) {
tp->fan_todo[FAN_CPU] = FAN_FULLBLAST;
} else if ((tick & (8 - 1)) == 0) {
s8 cpu_goal_hi = cpu_temp_limits[tp->index].high_warn - 10;
s8 cpu_goal_lo;
cpu_goal_lo = cpu_goal_hi - 3;
/* We do not try to avoid 'too cold' events. Basically we
* only try to deal with over-heating and fan noise reduction.
*/
if (tp->avg_cpu_temp < cpu_goal_hi) {
if (tp->avg_cpu_temp >= cpu_goal_lo)
tp->fan_todo[FAN_CPU] = FAN_SAME;
else
tp->fan_todo[FAN_CPU] = FAN_SLOWER;
} else {
tp->fan_todo[FAN_CPU] = FAN_FASTER;
}
} else {
tp->fan_todo[FAN_CPU] = FAN_SAME;
}
}
static void analyze_temps(struct bbc_cpu_temperature *tp, unsigned long *last_warn)
{
tp->avg_amb_temp = (s8)((int)((int)tp->avg_amb_temp + (int)tp->curr_amb_temp) / 2);
tp->avg_cpu_temp = (s8)((int)((int)tp->avg_cpu_temp + (int)tp->curr_cpu_temp) / 2);
analyze_ambient_temp(tp, last_warn, tp->sample_tick);
analyze_cpu_temp(tp, last_warn, tp->sample_tick);
tp->sample_tick++;
}
static enum fan_action prioritize_fan_action(int which_fan)
{
struct bbc_cpu_temperature *tp;
enum fan_action decision = FAN_STATE_MAX;
/* Basically, prioritize what the temperature sensors
* recommend we do, and perform that action on all the
* fans.
*/
for (tp = all_bbc_temps; tp; tp = tp->next) {
if (tp->fan_todo[which_fan] == FAN_FULLBLAST) {
decision = FAN_FULLBLAST;
break;
}
if (tp->fan_todo[which_fan] == FAN_SAME &&
decision != FAN_FASTER)
decision = FAN_SAME;
else if (tp->fan_todo[which_fan] == FAN_FASTER)
decision = FAN_FASTER;
else if (decision != FAN_FASTER &&
decision != FAN_SAME &&
tp->fan_todo[which_fan] == FAN_SLOWER)
decision = FAN_SLOWER;
}
if (decision == FAN_STATE_MAX)
decision = FAN_SAME;
return decision;
}
static int maybe_new_ambient_fan_speed(struct bbc_fan_control *fp)
{
enum fan_action decision = prioritize_fan_action(FAN_AMBIENT);
int ret;
if (decision == FAN_SAME)
return 0;
ret = 1;
if (decision == FAN_FULLBLAST) {
if (fp->system_fan_speed >= FAN_SPEED_MAX)
ret = 0;
else
fp->system_fan_speed = FAN_SPEED_MAX;
} else {
if (decision == FAN_FASTER) {
if (fp->system_fan_speed >= FAN_SPEED_MAX)
ret = 0;
else
fp->system_fan_speed += 2;
} else {
int orig_speed = fp->system_fan_speed;
if (orig_speed <= FAN_SPEED_MIN ||
orig_speed <= (fp->cpu_fan_speed - 3))
ret = 0;
else
fp->system_fan_speed -= 1;
}
}
return ret;
}
static int maybe_new_cpu_fan_speed(struct bbc_fan_control *fp)
{
enum fan_action decision = prioritize_fan_action(FAN_CPU);
int ret;
if (decision == FAN_SAME)
return 0;
ret = 1;
if (decision == FAN_FULLBLAST) {
if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
ret = 0;
else
fp->cpu_fan_speed = FAN_SPEED_MAX;
} else {
if (decision == FAN_FASTER) {
if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
ret = 0;
else {
fp->cpu_fan_speed += 2;
if (fp->system_fan_speed <
(fp->cpu_fan_speed - 3))
fp->system_fan_speed =
fp->cpu_fan_speed - 3;
}
} else {
if (fp->cpu_fan_speed <= FAN_SPEED_MIN)
ret = 0;
else
fp->cpu_fan_speed -= 1;
}
}
return ret;
}
static void maybe_new_fan_speeds(struct bbc_fan_control *fp)
{
int new;
new = maybe_new_ambient_fan_speed(fp);
new |= maybe_new_cpu_fan_speed(fp);
if (new)
set_fan_speeds(fp);
}
static void fans_full_blast(void)
{
struct bbc_fan_control *fp;
/* Since we will not be monitoring things anymore, put
* the fans on full blast.
*/
for (fp = all_bbc_fans; fp; fp = fp->next) {
fp->cpu_fan_speed = FAN_SPEED_MAX;
fp->system_fan_speed = FAN_SPEED_MAX;
fp->psupply_fan_on = 1;
set_fan_speeds(fp);
}
}
#define POLL_INTERVAL (5 * 1000)
static unsigned long last_warning_jiffies;
static struct task_struct *kenvctrld_task;
static int kenvctrld(void *__unused)
{
printk(KERN_INFO "bbc_envctrl: kenvctrld starting...\n");
last_warning_jiffies = jiffies - WARN_INTERVAL;
for (;;) {
struct bbc_cpu_temperature *tp;
struct bbc_fan_control *fp;
msleep_interruptible(POLL_INTERVAL);
if (kthread_should_stop())
break;
for (tp = all_bbc_temps; tp; tp = tp->next) {
get_current_temps(tp);
analyze_temps(tp, &last_warning_jiffies);
}
for (fp = all_bbc_fans; fp; fp = fp->next)
maybe_new_fan_speeds(fp);
}
printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n");
fans_full_blast();
return 0;
}
static void attach_one_temp(struct linux_ebus_child *echild, int temp_idx)
{
struct bbc_cpu_temperature *tp = kmalloc(sizeof(*tp), GFP_KERNEL);
if (!tp)
return;
memset(tp, 0, sizeof(*tp));
tp->client = bbc_i2c_attach(echild);
if (!tp->client) {
kfree(tp);
return;
}
tp->index = temp_idx;
{
struct bbc_cpu_temperature **tpp = &all_bbc_temps;
while (*tpp)
tpp = &((*tpp)->next);
tp->next = NULL;
*tpp = tp;
}
/* Tell it to convert once every 5 seconds, clear all cfg
* bits.
*/
bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE);
bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE);
/* Program the hard temperature limits into the chip. */
bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff,
MAX1617_WR_AMB_HIGHLIM);
bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff,
MAX1617_WR_AMB_LOWLIM);
bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff,
MAX1617_WR_CPU_HIGHLIM);
bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff,
MAX1617_WR_CPU_LOWLIM);
get_current_temps(tp);
tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp;
tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp;
tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
tp->fan_todo[FAN_CPU] = FAN_SAME;
}
static void attach_one_fan(struct linux_ebus_child *echild, int fan_idx)
{
struct bbc_fan_control *fp = kmalloc(sizeof(*fp), GFP_KERNEL);
if (!fp)
return;
memset(fp, 0, sizeof(*fp));
fp->client = bbc_i2c_attach(echild);
if (!fp->client) {
kfree(fp);
return;
}
fp->index = fan_idx;
{
struct bbc_fan_control **fpp = &all_bbc_fans;
while (*fpp)
fpp = &((*fpp)->next);
fp->next = NULL;
*fpp = fp;
}
/* The i2c device controlling the fans is write-only.
* So the only way to keep track of the current power
* level fed to the fans is via software. Choose half
* power for cpu/system and 'on' fo the powersupply fan
* and set it now.
*/
fp->psupply_fan_on = 1;
fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
fp->cpu_fan_speed += FAN_SPEED_MIN;
fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
fp->system_fan_speed += FAN_SPEED_MIN;
set_fan_speeds(fp);
}
int bbc_envctrl_init(void)
{
struct linux_ebus_child *echild;
int temp_index = 0;
int fan_index = 0;
int devidx = 0;
while ((echild = bbc_i2c_getdev(devidx++)) != NULL) {
if (!strcmp(echild->prom_node->name, "temperature"))
attach_one_temp(echild, temp_index++);
if (!strcmp(echild->prom_node->name, "fan-control"))
attach_one_fan(echild, fan_index++);
}
if (temp_index != 0 && fan_index != 0) {
kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
if (IS_ERR(kenvctrld_task))
return PTR_ERR(kenvctrld_task);
}
return 0;
}
static void destroy_one_temp(struct bbc_cpu_temperature *tp)
{
bbc_i2c_detach(tp->client);
kfree(tp);
}
static void destroy_one_fan(struct bbc_fan_control *fp)
{
bbc_i2c_detach(fp->client);
kfree(fp);
}
void bbc_envctrl_cleanup(void)
{
struct bbc_cpu_temperature *tp;
struct bbc_fan_control *fp;
kthread_stop(kenvctrld_task);
tp = all_bbc_temps;
while (tp != NULL) {
struct bbc_cpu_temperature *next = tp->next;
destroy_one_temp(tp);
tp = next;
}
all_bbc_temps = NULL;
fp = all_bbc_fans;
while (fp != NULL) {
struct bbc_fan_control *next = fp->next;
destroy_one_fan(fp);
fp = next;
}
all_bbc_fans = NULL;
}
