[linux-2.6-block.git] / drivers / sbus / char / bbc_envctrl.c

/* 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/of_device.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;
	if (orderly_poweroff(true) < 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.
	 */
	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 of_device *op,
			    int temp_idx)
{
	struct bbc_cpu_temperature *tp;

	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
	if (!tp)
		return;

	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 of_device *op,
			   int fan_idx)
{
	struct bbc_fan_control *fp;

	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
	if (!fp)
		return;

	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);
}

int bbc_envctrl_init(struct bbc_i2c_bus *bp)
{
	struct of_device *op;
	int temp_index = 0;
	int fan_index = 0;
	int devidx = 0;

	while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) {
		if (!strcmp(op->node->name, "temperature"))
			attach_one_temp(bp, op, temp_index++);
		if (!strcmp(op->node->name, "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;
			return err;
		}
	}

	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(struct bbc_i2c_bus *bp)
{
	struct bbc_cpu_temperature *tp, *tpos;
	struct bbc_fan_control *fp, *fpos;

	if (kenvctrld_task)
		kthread_stop(kenvctrld_task);

	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);
	}

	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);
	}
}
Commit	Line	Data
e21e245b	1	/* bbc_envctrl.c: UltraSPARC-III environment control driver.
1da177e4	2	*
e21e245b	3	* Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
1da177e4 LT	4	*/
1da177e4 LT	5
bc240668	6	#include <linux/kthread.h>
1da177e4	7	#include <linux/delay.h>
872ec648	8	#include <linux/kmod.h>
10a0a8d4	9	#include <linux/reboot.h>
e21e245b DM	10	#include <linux/of.h>
e21e245b DM	11	#include <linux/of_device.h>
1da177e4	12	#include <asm/oplib.h>
1da177e4 LT	13
	14	#include "bbc_i2c.h"
	15	#include "max1617.h"
	16
	17	#undef ENVCTRL_TRACE
	18
	19	/* WARNING: Making changes to this driver is very dangerous.
	20	* If you misprogram the sensor chips they can
	21	* cut the power on you instantly.
	22	*/
	23
	24	/* Two temperature sensors exist in the SunBLADE-1000 enclosure.
	25	* Both are implemented using max1617 i2c devices. Each max1617
	26	* monitors 2 temperatures, one for one of the cpu dies and the other
	27	* for the ambient temperature.
	28	*
	29	* The max1617 is capable of being programmed with power-off
	30	* temperature values, one low limit and one high limit. These
	31	* can be controlled independently for the cpu or ambient temperature.
	32	* If a limit is violated, the power is simply shut off. The frequency
	33	* with which the max1617 does temperature sampling can be controlled
	34	* as well.
	35	*
	36	* Three fans exist inside the machine, all three are controlled with
	37	* an i2c digital to analog converter. There is a fan directed at the
	38	* two processor slots, another for the rest of the enclosure, and the
	39	* third is for the power supply. The first two fans may be speed
	40	* controlled by changing the voltage fed to them. The third fan may
	41	* only be completely off or on. The third fan is meant to only be
	42	* disabled/enabled when entering/exiting the lowest power-saving
	43	* mode of the machine.
	44	*
	45	* An environmental control kernel thread periodically monitors all
	46	* temperature sensors. Based upon the samples it will adjust the
	47	* fan speeds to try and keep the system within a certain temperature
	48	* range (the goal being to make the fans as quiet as possible without
	49	* allowing the system to get too hot).
	50	*
	51	* If the temperature begins to rise/fall outside of the acceptable
	52	* operating range, a periodic warning will be sent to the kernel log.
	53	* The fans will be put on full blast to attempt to deal with this
	54	* situation. After exceeding the acceptable operating range by a
	55	* certain threshold, the kernel thread will shut down the system.
	56	* Here, the thread is attempting to shut the machine down cleanly
	57	* before the hardware based power-off event is triggered.
	58	*/
	59
	60	/* These settings are in Celsius. We use these defaults only
	61	* if we cannot interrogate the cpu-fru SEEPROM.
	62	*/
	63	struct temp_limits {
	64	s8 high_pwroff, high_shutdown, high_warn;
	65	s8 low_warn, low_shutdown, low_pwroff;
	66	};
	67
	68	static struct temp_limits cpu_temp_limits[2] = {
	69	{ 100, 85, 80, 5, -5, -10 },
	70	{ 100, 85, 80, 5, -5, -10 },
	71	};
	72
	73	static struct temp_limits amb_temp_limits[2] = {
	74	{ 65, 55, 40, 5, -5, -10 },
	75	{ 65, 55, 40, 5, -5, -10 },
	76	};
77
e21e245b DM	78	static LIST_HEAD(all_temps);
e21e245b DM	79	static LIST_HEAD(all_fans);
1da177e4 LT	80
	81	#define CPU_FAN_REG 0xf0
	82	#define SYS_FAN_REG 0xf2
	83	#define PSUPPLY_FAN_REG 0xf4
	84
	85	#define FAN_SPEED_MIN 0x0c
	86	#define FAN_SPEED_MAX 0x3f
	87
	88	#define PSUPPLY_FAN_ON 0x1f
	89	#define PSUPPLY_FAN_OFF 0x00
	90
	91	static void set_fan_speeds(struct bbc_fan_control *fp)
	92	{
	93	/* Put temperatures into range so we don't mis-program
	94	* the hardware.
	95	*/
	96	if (fp->cpu_fan_speed < FAN_SPEED_MIN)
	97	fp->cpu_fan_speed = FAN_SPEED_MIN;
	98	if (fp->cpu_fan_speed > FAN_SPEED_MAX)
	99	fp->cpu_fan_speed = FAN_SPEED_MAX;
	100	if (fp->system_fan_speed < FAN_SPEED_MIN)
	101	fp->system_fan_speed = FAN_SPEED_MIN;
	102	if (fp->system_fan_speed > FAN_SPEED_MAX)
	103	fp->system_fan_speed = FAN_SPEED_MAX;
	104	#ifdef ENVCTRL_TRACE
	105	printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
	106	fp->index,
	107	fp->cpu_fan_speed, fp->system_fan_speed);
	108	#endif
	109
	110	bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG);
	111	bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG);
	112	bbc_i2c_writeb(fp->client,
	113	(fp->psupply_fan_on ?
	114	PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF),
	115	PSUPPLY_FAN_REG);
	116	}
	117
	118	static void get_current_temps(struct bbc_cpu_temperature *tp)
	119	{
	120	tp->prev_amb_temp = tp->curr_amb_temp;
	121	bbc_i2c_readb(tp->client,
	122	(unsigned char *) &tp->curr_amb_temp,
	123	MAX1617_AMB_TEMP);
	124	tp->prev_cpu_temp = tp->curr_cpu_temp;
	125	bbc_i2c_readb(tp->client,
	126	(unsigned char *) &tp->curr_cpu_temp,
	127	MAX1617_CPU_TEMP);
	128	#ifdef ENVCTRL_TRACE
	129	printk("temp%d: cpu(%d C) amb(%d C)\n",
	130	tp->index,
	131	(int) tp->curr_cpu_temp, (int) tp->curr_amb_temp);
	132	#endif
	133	}
	134
	135
	136	static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
	137	{
	138	static int shutting_down = 0;
1da177e4 LT	139	char *type = "???";
	140	s8 val = -1;
	141
	142	if (shutting_down != 0)
	143	return;
	144
	145	if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown \|\|
	146	tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
	147	type = "ambient";
	148	val = tp->curr_amb_temp;
	149	} else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown \|\|
	150	tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
	151	type = "CPU";
	152	val = tp->curr_cpu_temp;
	153	}
	154
	155	printk(KERN_CRIT "temp%d: Outside of safe %s "
	156	"operating temperature, %d C.\n",
	157	tp->index, type, val);
	158
	159	printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
	160
	161	shutting_down = 1;
10a0a8d4	162	if (orderly_poweroff(true) < 0)
1da177e4 LT	163	printk(KERN_CRIT "envctrl: shutdown execution failed\n");
	164	}
	165
	166	#define WARN_INTERVAL (30 * HZ)
	167
	168	static void analyze_ambient_temp(struct bbc_cpu_temperature tp, unsigned long last_warn, int tick)
	169	{
	170	int ret = 0;
	171
	172	if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
	173	if (tp->curr_amb_temp >=
	174	amb_temp_limits[tp->index].high_warn) {
	175	printk(KERN_WARNING "temp%d: "
	176	"Above safe ambient operating temperature, %d C.\n",
	177	tp->index, (int) tp->curr_amb_temp);
	178	ret = 1;
	179	} else if (tp->curr_amb_temp <
	180	amb_temp_limits[tp->index].low_warn) {
	181	printk(KERN_WARNING "temp%d: "
	182	"Below safe ambient operating temperature, %d C.\n",
	183	tp->index, (int) tp->curr_amb_temp);
	184	ret = 1;
	185	}
	186	if (ret)
	187	*last_warn = jiffies;
	188	} else if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_warn \|\|
	189	tp->curr_amb_temp < amb_temp_limits[tp->index].low_warn)
	190	ret = 1;
	191
	192	/* Now check the shutdown limits. */
	193	if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown \|\|
	194	tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
	195	do_envctrl_shutdown(tp);
	196	ret = 1;
	197	}
	198
	199	if (ret) {
	200	tp->fan_todo[FAN_AMBIENT] = FAN_FULLBLAST;
	201	} else if ((tick & (8 - 1)) == 0) {
	202	s8 amb_goal_hi = amb_temp_limits[tp->index].high_warn - 10;
	203	s8 amb_goal_lo;
	204
	205	amb_goal_lo = amb_goal_hi - 3;
	206
	207	/* We do not try to avoid 'too cold' events. Basically we
	208	* only try to deal with over-heating and fan noise reduction.
	209	*/
	210	if (tp->avg_amb_temp < amb_goal_hi) {
	211	if (tp->avg_amb_temp >= amb_goal_lo)
	212	tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
	213	else
	214	tp->fan_todo[FAN_AMBIENT] = FAN_SLOWER;
	215	} else {
	216	tp->fan_todo[FAN_AMBIENT] = FAN_FASTER;
	217	}
	218	} else {
	219	tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
	220	}
	221	}
	222
	223	static void analyze_cpu_temp(struct bbc_cpu_temperature tp, unsigned long last_warn, int tick)
	224	{
	225	int ret = 0;
	226
227	if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
228	if (tp->curr_cpu_temp >=
229	cpu_temp_limits[tp->index].high_warn) {
230	printk(KERN_WARNING "temp%d: "
231	"Above safe CPU operating temperature, %d C.\n",
232	tp->index, (int) tp->curr_cpu_temp);
233	ret = 1;
234	} else if (tp->curr_cpu_temp <
235	cpu_temp_limits[tp->index].low_warn) {
236	printk(KERN_WARNING "temp%d: "
237	"Below safe CPU operating temperature, %d C.\n",
238	tp->index, (int) tp->curr_cpu_temp);
239	ret = 1;
240	}
241	if (ret)
242	*last_warn = jiffies;
243	} else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_warn \|\|
244	tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_warn)
245	ret = 1;
246
247	/* Now check the shutdown limits. */
248	if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown \|\|
249	tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
250	do_envctrl_shutdown(tp);
251	ret = 1;
252	}
253
254	if (ret) {
255	tp->fan_todo[FAN_CPU] = FAN_FULLBLAST;
256	} else if ((tick & (8 - 1)) == 0) {
257	s8 cpu_goal_hi = cpu_temp_limits[tp->index].high_warn - 10;
258	s8 cpu_goal_lo;
259
260	cpu_goal_lo = cpu_goal_hi - 3;
261
262	/* We do not try to avoid 'too cold' events. Basically we
263	* only try to deal with over-heating and fan noise reduction.
264	*/
265	if (tp->avg_cpu_temp < cpu_goal_hi) {
266	if (tp->avg_cpu_temp >= cpu_goal_lo)
267	tp->fan_todo[FAN_CPU] = FAN_SAME;
268	else
269	tp->fan_todo[FAN_CPU] = FAN_SLOWER;
270	} else {
271	tp->fan_todo[FAN_CPU] = FAN_FASTER;
272	}
273	} else {
274	tp->fan_todo[FAN_CPU] = FAN_SAME;
275	}
276	}
277
278	static void analyze_temps(struct bbc_cpu_temperature tp, unsigned long last_warn)
279	{
280	tp->avg_amb_temp = (s8)((int)((int)tp->avg_amb_temp + (int)tp->curr_amb_temp) / 2);
281	tp->avg_cpu_temp = (s8)((int)((int)tp->avg_cpu_temp + (int)tp->curr_cpu_temp) / 2);
282
283	analyze_ambient_temp(tp, last_warn, tp->sample_tick);
284	analyze_cpu_temp(tp, last_warn, tp->sample_tick);
285
286	tp->sample_tick++;
287	}
288
289	static enum fan_action prioritize_fan_action(int which_fan)
290	{
291	struct bbc_cpu_temperature *tp;
292	enum fan_action decision = FAN_STATE_MAX;
293
294	/* Basically, prioritize what the temperature sensors
295	* recommend we do, and perform that action on all the
296	* fans.
297	*/
e21e245b	298	list_for_each_entry(tp, &all_temps, glob_list) {
1da177e4 LT	299	if (tp->fan_todo[which_fan] == FAN_FULLBLAST) {
	300	decision = FAN_FULLBLAST;
	301	break;
	302	}
	303	if (tp->fan_todo[which_fan] == FAN_SAME &&
	304	decision != FAN_FASTER)
	305	decision = FAN_SAME;
	306	else if (tp->fan_todo[which_fan] == FAN_FASTER)
	307	decision = FAN_FASTER;
	308	else if (decision != FAN_FASTER &&
	309	decision != FAN_SAME &&
	310	tp->fan_todo[which_fan] == FAN_SLOWER)
	311	decision = FAN_SLOWER;
	312	}
	313	if (decision == FAN_STATE_MAX)
	314	decision = FAN_SAME;
	315
	316	return decision;
	317	}
	318
	319	static int maybe_new_ambient_fan_speed(struct bbc_fan_control *fp)
	320	{
	321	enum fan_action decision = prioritize_fan_action(FAN_AMBIENT);
	322	int ret;
	323
	324	if (decision == FAN_SAME)
	325	return 0;
	326
	327	ret = 1;
	328	if (decision == FAN_FULLBLAST) {
	329	if (fp->system_fan_speed >= FAN_SPEED_MAX)
	330	ret = 0;
	331	else
	332	fp->system_fan_speed = FAN_SPEED_MAX;
	333	} else {
	334	if (decision == FAN_FASTER) {
	335	if (fp->system_fan_speed >= FAN_SPEED_MAX)
	336	ret = 0;
	337	else
	338	fp->system_fan_speed += 2;
	339	} else {
	340	int orig_speed = fp->system_fan_speed;
	341
	342	if (orig_speed <= FAN_SPEED_MIN \|\|
	343	orig_speed <= (fp->cpu_fan_speed - 3))
	344	ret = 0;
	345	else
	346	fp->system_fan_speed -= 1;
	347	}
	348	}
	349
	350	return ret;
	351	}
	352
	353	static int maybe_new_cpu_fan_speed(struct bbc_fan_control *fp)
	354	{
	355	enum fan_action decision = prioritize_fan_action(FAN_CPU);
	356	int ret;
	357
	358	if (decision == FAN_SAME)
	359	return 0;
	360
	361	ret = 1;
	362	if (decision == FAN_FULLBLAST) {
363	if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
364	ret = 0;
365	else
366	fp->cpu_fan_speed = FAN_SPEED_MAX;
367	} else {
368	if (decision == FAN_FASTER) {
369	if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
370	ret = 0;
371	else {
372	fp->cpu_fan_speed += 2;
373	if (fp->system_fan_speed <
374	(fp->cpu_fan_speed - 3))
375	fp->system_fan_speed =
376	fp->cpu_fan_speed - 3;
377	}
378	} else {
379	if (fp->cpu_fan_speed <= FAN_SPEED_MIN)
380	ret = 0;
381	else
382	fp->cpu_fan_speed -= 1;
383	}
384	}
385
386	return ret;
387	}
388
389	static void maybe_new_fan_speeds(struct bbc_fan_control *fp)
390	{
391	int new;
392
393	new = maybe_new_ambient_fan_speed(fp);
394	new \|= maybe_new_cpu_fan_speed(fp);
395
396	if (new)
397	set_fan_speeds(fp);
398	}
399
400	static void fans_full_blast(void)
401	{
402	struct bbc_fan_control *fp;
403
404	/* Since we will not be monitoring things anymore, put
405	* the fans on full blast.
406	*/
e21e245b	407	list_for_each_entry(fp, &all_fans, glob_list) {
1da177e4 LT	408	fp->cpu_fan_speed = FAN_SPEED_MAX;
	409	fp->system_fan_speed = FAN_SPEED_MAX;
	410	fp->psupply_fan_on = 1;
	411	set_fan_speeds(fp);
	412	}
	413	}
	414
	415	#define POLL_INTERVAL (5 * 1000)
	416	static unsigned long last_warning_jiffies;
	417	static struct task_struct *kenvctrld_task;
	418
	419	static int kenvctrld(void *__unused)
	420	{
1da177e4 LT	421	printk(KERN_INFO "bbc_envctrl: kenvctrld starting...\n");
	422	last_warning_jiffies = jiffies - WARN_INTERVAL;
	423	for (;;) {
	424	struct bbc_cpu_temperature *tp;
	425	struct bbc_fan_control *fp;
	426
	427	msleep_interruptible(POLL_INTERVAL);
bc240668	428	if (kthread_should_stop())
1da177e4 LT	429	break;
1da177e4 LT	430
e21e245b	431	list_for_each_entry(tp, &all_temps, glob_list) {
1da177e4 LT	432	get_current_temps(tp);
	433	analyze_temps(tp, &last_warning_jiffies);
	434	}
e21e245b	435	list_for_each_entry(fp, &all_fans, glob_list)
1da177e4 LT	436	maybe_new_fan_speeds(fp);
	437	}
	438	printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n");
	439
	440	fans_full_blast();
	441
	442	return 0;
	443	}
	444
e21e245b DM	445	static void attach_one_temp(struct bbc_i2c_bus bp, struct of_device op,
e21e245b DM	446	int temp_idx)
1da177e4	447	{
916e89fd	448	struct bbc_cpu_temperature *tp;
1da177e4	449
916e89fd	450	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
1da177e4 LT	451	if (!tp)
1da177e4 LT	452	return;
916e89fd	453
39890072	454	tp->client = bbc_i2c_attach(bp, op);
1da177e4 LT	455	if (!tp->client) {
	456	kfree(tp);
	457	return;
	458	}
	459
e21e245b	460
1da177e4	461	tp->index = temp_idx;
e21e245b DM	462
	463	list_add(&tp->glob_list, &all_temps);
	464	list_add(&tp->bp_list, &bp->temps);
1da177e4 LT	465
	466	/* Tell it to convert once every 5 seconds, clear all cfg
	467	* bits.
	468	*/
	469	bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE);
	470	bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE);
	471
	472	/* Program the hard temperature limits into the chip. */
	473	bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff,
	474	MAX1617_WR_AMB_HIGHLIM);
	475	bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff,
	476	MAX1617_WR_AMB_LOWLIM);
	477	bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff,
	478	MAX1617_WR_CPU_HIGHLIM);
	479	bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff,
	480	MAX1617_WR_CPU_LOWLIM);
	481
	482	get_current_temps(tp);
	483	tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp;
	484	tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp;
	485
	486	tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
	487	tp->fan_todo[FAN_CPU] = FAN_SAME;
	488	}
	489
e21e245b DM	490	static void attach_one_fan(struct bbc_i2c_bus bp, struct of_device op,
e21e245b DM	491	int fan_idx)
1da177e4	492	{
916e89fd	493	struct bbc_fan_control *fp;
1da177e4	494
916e89fd	495	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
1da177e4 LT	496	if (!fp)
1da177e4 LT	497	return;
916e89fd	498
39890072	499	fp->client = bbc_i2c_attach(bp, op);
1da177e4 LT	500	if (!fp->client) {
	501	kfree(fp);
	502	return;
	503	}
	504
	505	fp->index = fan_idx;
	506
e21e245b DM	507	list_add(&fp->glob_list, &all_fans);
e21e245b DM	508	list_add(&fp->bp_list, &bp->fans);
1da177e4 LT	509
	510	/* The i2c device controlling the fans is write-only.
	511	* So the only way to keep track of the current power
	512	* level fed to the fans is via software. Choose half
	513	* power for cpu/system and 'on' fo the powersupply fan
	514	* and set it now.
	515	*/
	516	fp->psupply_fan_on = 1;
	517	fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
	518	fp->cpu_fan_speed += FAN_SPEED_MIN;
	519	fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
	520	fp->system_fan_speed += FAN_SPEED_MIN;
	521
	522	set_fan_speeds(fp);
	523	}
	524
e21e245b	525	int bbc_envctrl_init(struct bbc_i2c_bus *bp)
1da177e4	526	{
e21e245b	527	struct of_device *op;
1da177e4 LT	528	int temp_index = 0;
	529	int fan_index = 0;
	530	int devidx = 0;
1da177e4	531
39890072	532	while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) {
e21e245b DM	533	if (!strcmp(op->node->name, "temperature"))
	534	attach_one_temp(bp, op, temp_index++);
	535	if (!strcmp(op->node->name, "fan-control"))
	536	attach_one_fan(bp, op, fan_index++);
1da177e4	537	}
bc240668 CH	538	if (temp_index != 0 && fan_index != 0) {
bc240668 CH	539	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
14d87e6c DM	540	if (IS_ERR(kenvctrld_task)) {
	541	int err = PTR_ERR(kenvctrld_task);
	542
	543	kenvctrld_task = NULL;
	544	return err;
	545	}
bc240668 CH	546	}
	547
	548	return 0;
1da177e4 LT	549	}
	550
	551	static void destroy_one_temp(struct bbc_cpu_temperature *tp)
	552	{
	553	bbc_i2c_detach(tp->client);
	554	kfree(tp);
	555	}
	556
	557	static void destroy_one_fan(struct bbc_fan_control *fp)
	558	{
	559	bbc_i2c_detach(fp->client);
	560	kfree(fp);
	561	}
	562
e21e245b	563	void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp)
1da177e4	564	{
e21e245b DM	565	struct bbc_cpu_temperature tp, tpos;
e21e245b DM	566	struct bbc_fan_control fp, fpos;
1da177e4	567
14d87e6c DM	568	if (kenvctrld_task)
14d87e6c DM	569	kthread_stop(kenvctrld_task);
1da177e4	570
e21e245b DM	571	list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) {
	572	list_del(&tp->bp_list);
	573	list_del(&tp->glob_list);
1da177e4	574	destroy_one_temp(tp);
1da177e4	575	}
1da177e4	576
e21e245b DM	577	list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) {
	578	list_del(&fp->bp_list);
	579	list_del(&fp->glob_list);
1da177e4	580	destroy_one_fan(fp);
1da177e4	581	}
1da177e4	582	}