bbc_envctrl.c

MIZI Research, Inc.发布的嵌入式Linux内核源码

	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 * HZ)
static unsigned long last_warning_jiffies;
static struct task_struct *kenvctrld_task;

static int kenvctrld(void *__unused)
{
	daemonize();
	strcpy(current->comm, "kenvctrld");
	kenvctrld_task = current;

	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;

		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout(POLL_INTERVAL);
		current->state = TASK_RUNNING;
		if (signal_pending(current))
			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);
}

void 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_name, "temperature"))
			attach_one_temp(echild, temp_index++);
		if (!strcmp(echild->prom_name, "fan-control"))
			attach_one_fan(echild, fan_index++);
	}
	if (temp_index != 0 && fan_index != 0)
		kernel_thread(kenvctrld, NULL, CLONE_FS | CLONE_FILES);
}

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;

	if (kenvctrld_task != NULL) {
		force_sig(SIGKILL, kenvctrld_task);
		for (;;) {
			struct task_struct *p;
			int found = 0;

			read_lock(&tasklist_lock);
			for_each_task(p) {
				if (p == kenvctrld_task) {
					found = 1;
					break;
				}
			}
			read_unlock(&tasklist_lock);
			if (!found)
				break;
			current->state = TASK_INTERRUPTIBLE;
			schedule_timeout(HZ);
			current->state = TASK_RUNNING;
		}
		kenvctrld_task = NULL;
	}

	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;
}