/* $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) */ #include <linux/kthread.h> #include <linux/delay.h> #include <linux/kmod.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 (call_usermodehelper("/sbin/shutdown", argv, envp, 0) < 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; }