therm_pm72.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,340 行 · 第 1/3 页

		return;
	state->ticks = DRIVES_PID_INTERVAL;

	DBG("drives:\n");

	/* Check fan status */
	rc = get_rpm_fan(DRIVES_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
	if (rc < 0) {
		printk(KERN_WARNING "Error %d reading drives fan !\n", rc);
		/* XXX What do we do now ? */
	} else
		state->rpm = rc;
	DBG("  current rpm: %d\n", state->rpm);

	/* Get some sensor readings */
	temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor, DS1775_TEMP)) << 8;
	state->last_temp = temp;
	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
	    FIX32TOPRINT(DRIVES_PID_INPUT_TARGET));

	/* Store temperature and error in history array */
	state->cur_sample = (state->cur_sample + 1) % DRIVES_PID_HISTORY_SIZE;
	state->sample_history[state->cur_sample] = temp;
	state->error_history[state->cur_sample] = temp - DRIVES_PID_INPUT_TARGET;
	
	/* If first loop, fill the history table */
	if (state->first) {
		for (i = 0; i < (DRIVES_PID_HISTORY_SIZE - 1); i++) {
			state->cur_sample = (state->cur_sample + 1) %
				DRIVES_PID_HISTORY_SIZE;
			state->sample_history[state->cur_sample] = temp;
			state->error_history[state->cur_sample] =
				temp - DRIVES_PID_INPUT_TARGET;
		}
		state->first = 0;
	}

	/* Calculate the integral term */
	sum = 0;
	integral = 0;
	for (i = 0; i < DRIVES_PID_HISTORY_SIZE; i++)
		integral += state->error_history[i];
	integral *= DRIVES_PID_INTERVAL;
	DBG("  integral: %08x\n", integral);
	integ_p = ((s64)DRIVES_PID_G_r) * (s64)integral;
	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
	sum += integ_p;

	/* Calculate the derivative term */
	derivative = state->error_history[state->cur_sample] -
		state->error_history[(state->cur_sample + DRIVES_PID_HISTORY_SIZE - 1)
				    % DRIVES_PID_HISTORY_SIZE];
	derivative /= DRIVES_PID_INTERVAL;
	deriv_p = ((s64)DRIVES_PID_G_d) * (s64)derivative;
	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
	sum += deriv_p;

	/* Calculate the proportional term */
	prop_p = ((s64)DRIVES_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
	sum += prop_p;

	/* Scale sum */
	sum >>= 36;

	DBG("   sum: %d\n", (int)sum);
	state->rpm += (s32)sum;
	if (state->rpm < DRIVES_PID_OUTPUT_MIN)
		state->rpm = DRIVES_PID_OUTPUT_MIN;
	if (state->rpm > DRIVES_PID_OUTPUT_MAX)
		state->rpm = DRIVES_PID_OUTPUT_MAX;

	DBG("** DRIVES RPM: %d\n", (int)state->rpm);
	set_rpm_fan(DRIVES_FAN_RPM_ID, state->rpm);
}

/*
 * Initialize the state structure for the drives bay fan control loop
 */
static int init_drives_state(struct drives_pid_state *state)
{
	state->ticks = 1;
	state->first = 1;
	state->rpm = 1000;

	state->monitor = attach_i2c_chip(DRIVES_DALLAS_ID, "drives_temp");
	if (state->monitor == NULL)
		return -ENODEV;

	device_create_file(&of_dev->dev, &dev_attr_drives_temperature);
	device_create_file(&of_dev->dev, &dev_attr_drives_fan_rpm);

	return 0;
}

/*
 * Dispose of the state data for the drives control loop
 */
static void dispose_drives_state(struct drives_pid_state *state)
{
	if (state->monitor == NULL)
		return;

	device_remove_file(&of_dev->dev, &dev_attr_drives_temperature);
	device_remove_file(&of_dev->dev, &dev_attr_drives_fan_rpm);

	detach_i2c_chip(state->monitor);
	state->monitor = NULL;
}

static int call_critical_overtemp(void)
{
	char *argv[] = { critical_overtemp_path, NULL };
	static char *envp[] = { "HOME=/",
				"TERM=linux",
				"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
				NULL };

	return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
}


/*
 * Here's the kernel thread that calls the various control loops
 */
static int main_control_loop(void *x)
{
	daemonize("kfand");

	DBG("main_control_loop started\n");

	down(&driver_lock);

	if (start_fcu() < 0) {
		printk(KERN_ERR "kfand: failed to start FCU\n");
		up(&driver_lock);
		goto out;
	}

	/* Set the PCI fan once for now */
	set_pwm_fan(SLOTS_FAN_PWM_ID, SLOTS_FAN_DEFAULT_PWM);

	/* Initialize ADCs */
	initialize_adc(&cpu_state[0]);
	if (cpu_state[1].monitor != NULL)
		initialize_adc(&cpu_state[1]);

	up(&driver_lock);

	while (state == state_attached) {
		unsigned long elapsed, start;

		start = jiffies;

		down(&driver_lock);
		do_monitor_cpu(&cpu_state[0]);
		if (cpu_state[1].monitor != NULL)
			do_monitor_cpu(&cpu_state[1]);
		do_monitor_backside(&backside_state);
		do_monitor_drives(&drives_state);
		up(&driver_lock);

		if (critical_state == 1) {
			printk(KERN_WARNING "Temperature control detected a critical condition\n");
			printk(KERN_WARNING "Attempting to shut down...\n");
			if (call_critical_overtemp()) {
				printk(KERN_WARNING "Can't call %s, power off now!\n",
				       critical_overtemp_path);
				machine_power_off();
			}
		}
		if (critical_state > 0)
			critical_state++;
		if (critical_state > MAX_CRITICAL_STATE) {
			printk(KERN_WARNING "Shutdown timed out, power off now !\n");
			machine_power_off();
		}

		// FIXME: Deal with signals
		set_current_state(TASK_INTERRUPTIBLE);
		elapsed = jiffies - start;
		if (elapsed < HZ)
			schedule_timeout(HZ - elapsed);
	}

 out:
	DBG("main_control_loop ended\n");

	ctrl_task = 0;
	complete_and_exit(&ctrl_complete, 0);
}

/*
 * Dispose the control loops when tearing down
 */
static void dispose_control_loops(void)
{
	dispose_cpu_state(&cpu_state[0]);
	dispose_cpu_state(&cpu_state[1]);

	dispose_backside_state(&backside_state);
	dispose_drives_state(&drives_state);
}

/*
 * Create the control loops. U3-0 i2c bus is up, so we can now
 * get to the various sensors
 */
static int create_control_loops(void)
{
	struct device_node *np;

	/* Count CPUs from the device-tree, we don't care how many are
	 * actually used by Linux
	 */
	cpu_count = 0;
	for (np = NULL; NULL != (np = of_find_node_by_type(np, "cpu"));)
		cpu_count++;

	DBG("counted %d CPUs in the device-tree\n", cpu_count);

	/* Create control loops for everything. If any fail, everything
	 * fails
	 */
	if (init_cpu_state(&cpu_state[0], 0))
		goto fail;
	if (cpu_count > 1 && init_cpu_state(&cpu_state[1], 1))
		goto fail;
	if (init_backside_state(&backside_state))
		goto fail;
	if (init_drives_state(&drives_state))
		goto fail;

	DBG("all control loops up !\n");

	return 0;
	
 fail:
	DBG("failure creating control loops, disposing\n");

	dispose_control_loops();

	return -ENODEV;
}

/*
 * Start the control loops after everything is up, that is create
 * the thread that will make them run
 */
static void start_control_loops(void)
{
	init_completion(&ctrl_complete);

	ctrl_task = kernel_thread(main_control_loop, NULL, SIGCHLD | CLONE_KERNEL);
}

/*
 * Stop the control loops when tearing down
 */
static void stop_control_loops(void)
{
	if (ctrl_task != 0)
		wait_for_completion(&ctrl_complete);
}

/*
 * Attach to the i2c FCU after detecting U3-1 bus
 */
static int attach_fcu(void)
{
	fcu = attach_i2c_chip(FAN_CTRLER_ID, "fcu");
	if (fcu == NULL)
		return -ENODEV;

	DBG("FCU attached\n");

	return 0;
}

/*
 * Detach from the i2c FCU when tearing down
 */
static void detach_fcu(void)
{
	if (fcu)
		detach_i2c_chip(fcu);
	fcu = NULL;
}

/*
 * Attach to the i2c controller. We probe the various chips based
 * on the device-tree nodes and build everything for the driver to
 * run, we then kick the driver monitoring thread
 */
static int therm_pm72_attach(struct i2c_adapter *adapter)
{
	down(&driver_lock);

	/* Check state */
	if (state == state_detached)
		state = state_attaching;
	if (state != state_attaching) {
		up(&driver_lock);
		return 0;
	}

	/* Check if we are looking for one of these */
	if (u3_0 == NULL && !strcmp(adapter->name, "u3 0")) {
		u3_0 = adapter;
		DBG("found U3-0, creating control loops\n");
		if (create_control_loops())
			u3_0 = NULL;
	} else if (u3_1 == NULL && !strcmp(adapter->name, "u3 1")) {
		u3_1 = adapter;
		DBG("found U3-1, attaching FCU\n");
		if (attach_fcu())
			u3_1 = NULL;
	}
	/* We got all we need, start control loops */
	if (u3_0 != NULL && u3_1 != NULL) {
		DBG("everything up, starting control loops\n");
		state = state_attached;
		start_control_loops();
	}
	up(&driver_lock);

	return 0;
}

/*
 * Called on every adapter when the driver or the i2c controller
 * is going away.
 */
static int therm_pm72_detach(struct i2c_adapter *adapter)
{
	down(&driver_lock);

	if (state != state_detached)
		state = state_detaching;

	/* Stop control loops if any */
	DBG("stopping control loops\n");
	up(&driver_lock);
	stop_control_loops();
	down(&driver_lock);

	if (u3_0 != NULL && !strcmp(adapter->name, "u3 0")) {
		DBG("lost U3-0, disposing control loops\n");
		dispose_control_loops();
		u3_0 = NULL;
	}
	
	if (u3_1 != NULL && !strcmp(adapter->name, "u3 1")) {
		DBG("lost U3-1, detaching FCU\n");
		detach_fcu();
		u3_1 = NULL;
	}
	if (u3_0 == NULL && u3_1 == NULL)
		state = state_detached;

	up(&driver_lock);

	return 0;
}

static int fcu_of_probe(struct of_device* dev, const struct of_match *match)
{
	int rc;

	state = state_detached;

	rc = i2c_add_driver(&therm_pm72_driver);
	if (rc < 0)
		return rc;
	return 0;
}

static int fcu_of_remove(struct of_device* dev)
{
	i2c_del_driver(&therm_pm72_driver);

	return 0;
}

static struct of_match fcu_of_match[] = 
{
	{
	.name 		= OF_ANY_MATCH,
	.type		= "fcu",
	.compatible	= OF_ANY_MATCH
	},
	{},
};

static struct of_platform_driver fcu_of_platform_driver = 
{
	.name 		= "temperature",
	.match_table	= fcu_of_match,
	.probe		= fcu_of_probe,
	.remove		= fcu_of_remove
};

/*
 * Check machine type, attach to i2c controller
 */
static int __init therm_pm72_init(void)
{
	struct device_node *np;

	if (!machine_is_compatible("PowerMac7,2"))
	    	return -ENODEV;

	printk(KERN_INFO "PowerMac G5 Thermal control driver %s\n", VERSION);

	np = of_find_node_by_type(NULL, "fcu");
	if (np == NULL) {
		printk(KERN_ERR "Can't find FCU in device-tree !\n");
		return -ENODEV;
	}
	of_dev = of_platform_device_create(np, "temperature");
	if (of_dev == NULL) {
		printk(KERN_ERR "Can't register FCU platform device !\n");
		return -ENODEV;
	}

	of_register_driver(&fcu_of_platform_driver);
	
	return 0;
}

static void __exit therm_pm72_exit(void)
{
	of_unregister_driver(&fcu_of_platform_driver);

	if (of_dev)
		of_device_unregister(of_dev);
}

module_init(therm_pm72_init);
module_exit(therm_pm72_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <[e-mail]>");
MODULE_DESCRIPTION("Driver for Apple's PowerMac7,2 G5 thermal control");
MODULE_LICENSE("GPL");