diff options
Diffstat (limited to 'drivers/sbus/char/bbc_envctrl.c')
-rw-r--r-- | drivers/sbus/char/bbc_envctrl.c | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/drivers/sbus/char/bbc_envctrl.c b/drivers/sbus/char/bbc_envctrl.c new file mode 100644 index 0000000000..23af4edd29 --- /dev/null +++ b/drivers/sbus/char/bbc_envctrl.c @@ -0,0 +1,601 @@ +// SPDX-License-Identifier: GPL-2.0 +/* bbc_envctrl.c: UltraSPARC-III environment control driver. + * + * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net) + */ + +#include <linux/kthread.h> +#include <linux/delay.h> +#include <linux/kmod.h> +#include <linux/reboot.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <asm/oplib.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 }, +}; + +static LIST_HEAD(all_temps); +static LIST_HEAD(all_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; + 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; + orderly_poweroff(true); +} + +#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. + */ + list_for_each_entry(tp, &all_temps, glob_list) { + 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. + */ + list_for_each_entry(fp, &all_fans, glob_list) { + 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; + + list_for_each_entry(tp, &all_temps, glob_list) { + get_current_temps(tp); + analyze_temps(tp, &last_warning_jiffies); + } + list_for_each_entry(fp, &all_fans, glob_list) + maybe_new_fan_speeds(fp); + } + printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n"); + + fans_full_blast(); + + return 0; +} + +static void attach_one_temp(struct bbc_i2c_bus *bp, struct platform_device *op, + int temp_idx) +{ + struct bbc_cpu_temperature *tp; + + tp = kzalloc(sizeof(*tp), GFP_KERNEL); + if (!tp) + return; + + INIT_LIST_HEAD(&tp->bp_list); + INIT_LIST_HEAD(&tp->glob_list); + + tp->client = bbc_i2c_attach(bp, op); + if (!tp->client) { + kfree(tp); + return; + } + + + tp->index = temp_idx; + + list_add(&tp->glob_list, &all_temps); + list_add(&tp->bp_list, &bp->temps); + + /* 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 bbc_i2c_bus *bp, struct platform_device *op, + int fan_idx) +{ + struct bbc_fan_control *fp; + + fp = kzalloc(sizeof(*fp), GFP_KERNEL); + if (!fp) + return; + + INIT_LIST_HEAD(&fp->bp_list); + INIT_LIST_HEAD(&fp->glob_list); + + fp->client = bbc_i2c_attach(bp, op); + if (!fp->client) { + kfree(fp); + return; + } + + fp->index = fan_idx; + + list_add(&fp->glob_list, &all_fans); + list_add(&fp->bp_list, &bp->fans); + + /* 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); +} + +static void destroy_one_temp(struct bbc_cpu_temperature *tp) +{ + bbc_i2c_detach(tp->client); + kfree(tp); +} + +static void destroy_all_temps(struct bbc_i2c_bus *bp) +{ + struct bbc_cpu_temperature *tp, *tpos; + + list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) { + list_del(&tp->bp_list); + list_del(&tp->glob_list); + destroy_one_temp(tp); + } +} + +static void destroy_one_fan(struct bbc_fan_control *fp) +{ + bbc_i2c_detach(fp->client); + kfree(fp); +} + +static void destroy_all_fans(struct bbc_i2c_bus *bp) +{ + struct bbc_fan_control *fp, *fpos; + + list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) { + list_del(&fp->bp_list); + list_del(&fp->glob_list); + destroy_one_fan(fp); + } +} + +int bbc_envctrl_init(struct bbc_i2c_bus *bp) +{ + struct platform_device *op; + int temp_index = 0; + int fan_index = 0; + int devidx = 0; + + while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) { + if (of_node_name_eq(op->dev.of_node, "temperature")) + attach_one_temp(bp, op, temp_index++); + if (of_node_name_eq(op->dev.of_node, "fan-control")) + attach_one_fan(bp, op, fan_index++); + } + if (temp_index != 0 && fan_index != 0) { + kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld"); + if (IS_ERR(kenvctrld_task)) { + int err = PTR_ERR(kenvctrld_task); + + kenvctrld_task = NULL; + destroy_all_temps(bp); + destroy_all_fans(bp); + return err; + } + } + + return 0; +} + +void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp) +{ + if (kenvctrld_task) + kthread_stop(kenvctrld_task); + + destroy_all_temps(bp); + destroy_all_fans(bp); +} |