[deliverable/linux.git] / drivers / macintosh / windfarm_core.c

/*
 * Windfarm PowerMac thermal control. Core
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <benh@kernel.crashing.org>
 *
 * Released under the term of the GNU GPL v2.
 *
 * This core code tracks the list of sensors & controls, register
 * clients, and holds the kernel thread used for control.
 *
 * TODO:
 *
 * Add some information about sensor/control type and data format to
 * sensors/controls, and have the sysfs attribute stuff be moved
 * generically here instead of hard coded in the platform specific
 * driver as it us currently
 *
 * This however requires solving some annoying lifetime issues with
 * sysfs which doesn't seem to have lifetime rules for struct attribute,
 * I may have to create full features kobjects for every sensor/control
 * instead which is a bit of an overkill imho
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
#include <linux/kthread.h>
#include <linux/jiffies.h>
#include <linux/reboot.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/freezer.h>

#include <asm/prom.h>

#include "windfarm.h"

#define VERSION "0.2"

#undef DEBUG

#ifdef DEBUG
#define DBG(args...)	printk(args)
#else
#define DBG(args...)	do { } while(0)
#endif

static LIST_HEAD(wf_controls);
static LIST_HEAD(wf_sensors);
static DEFINE_MUTEX(wf_lock);
static BLOCKING_NOTIFIER_HEAD(wf_client_list);
static int wf_client_count;
static unsigned int wf_overtemp;
static unsigned int wf_overtemp_counter;
struct task_struct *wf_thread;

static struct platform_device wf_platform_device = {
	.name	= "windfarm",
};

/*
 * Utilities & tick thread
 */

static inline void wf_notify(int event, void *param)
{
	blocking_notifier_call_chain(&wf_client_list, event, param);
}

int wf_critical_overtemp(void)
{
	static char * critical_overtemp_path = "/sbin/critical_overtemp";
	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);
}
EXPORT_SYMBOL_GPL(wf_critical_overtemp);

static int wf_thread_func(void *data)
{
	unsigned long next, delay;

	next = jiffies;

	DBG("wf: thread started\n");

	while(!kthread_should_stop()) {
		try_to_freeze();

		if (time_after_eq(jiffies, next)) {
			wf_notify(WF_EVENT_TICK, NULL);
			if (wf_overtemp) {
				wf_overtemp_counter++;
				/* 10 seconds overtemp, notify userland */
				if (wf_overtemp_counter > 10)
					wf_critical_overtemp();
				/* 30 seconds, shutdown */
				if (wf_overtemp_counter > 30) {
					printk(KERN_ERR "windfarm: Overtemp "
					       "for more than 30"
					       " seconds, shutting down\n");
					machine_power_off();
				}
			}
			next += HZ;
		}

		delay = next - jiffies;
		if (delay <= HZ)
			schedule_timeout_interruptible(delay);

		/* there should be no signal, but oh well */
		if (signal_pending(current)) {
			printk(KERN_WARNING "windfarm: thread got sigl !\n");
			break;
		}
	}

	DBG("wf: thread stopped\n");

	return 0;
}

static void wf_start_thread(void)
{
	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	if (IS_ERR(wf_thread)) {
		printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
		       PTR_ERR(wf_thread));
		wf_thread = NULL;
	}
}


static void wf_stop_thread(void)
{
	if (wf_thread)
		kthread_stop(wf_thread);
	wf_thread = NULL;
}

/*
 * Controls
 */

static void wf_control_release(struct kref *kref)
{
	struct wf_control *ct = container_of(kref, struct wf_control, ref);

	DBG("wf: Deleting control %s\n", ct->name);

	if (ct->ops && ct->ops->release)
		ct->ops->release(ct);
	else
		kfree(ct);
}

static ssize_t wf_show_control(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	s32 val = 0;
	int err;

	err = ctrl->ops->get_value(ctrl, &val);
	if (err < 0)
		return err;
	return sprintf(buf, "%d\n", val);
}

/* This is really only for debugging... */
static ssize_t wf_store_control(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	int val;
	int err;
	char *endp;

	val = simple_strtoul(buf, &endp, 0);
	while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
		++endp;
	if (endp - buf < count)
		return -EINVAL;
	err = ctrl->ops->set_value(ctrl, val);
	if (err < 0)
		return err;
	return count;
}

int wf_register_control(struct wf_control *new_ct)
{
	struct wf_control *ct;

	mutex_lock(&wf_lock);
	list_for_each_entry(ct, &wf_controls, link) {
		if (!strcmp(ct->name, new_ct->name)) {
			printk(KERN_WARNING "windfarm: trying to register"
			       " duplicate control %s\n", ct->name);
			mutex_unlock(&wf_lock);
			return -EEXIST;
		}
	}
	kref_init(&new_ct->ref);
	list_add(&new_ct->link, &wf_controls);

	new_ct->attr.attr.name = new_ct->name;
	new_ct->attr.attr.owner = THIS_MODULE;
	new_ct->attr.attr.mode = 0644;
	new_ct->attr.show = wf_show_control;
	new_ct->attr.store = wf_store_control;
	device_create_file(&wf_platform_device.dev, &new_ct->attr);

	DBG("wf: Registered control %s\n", new_ct->name);

	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
	mutex_unlock(&wf_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(wf_register_control);

void wf_unregister_control(struct wf_control *ct)
{
	mutex_lock(&wf_lock);
	list_del(&ct->link);
	mutex_unlock(&wf_lock);

	DBG("wf: Unregistered control %s\n", ct->name);

	kref_put(&ct->ref, wf_control_release);
}
EXPORT_SYMBOL_GPL(wf_unregister_control);

struct wf_control * wf_find_control(const char *name)
{
	struct wf_control *ct;

	mutex_lock(&wf_lock);
	list_for_each_entry(ct, &wf_controls, link) {
		if (!strcmp(ct->name, name)) {
			if (wf_get_control(ct))
				ct = NULL;
			mutex_unlock(&wf_lock);
			return ct;
		}
	}
	mutex_unlock(&wf_lock);
	return NULL;
}
EXPORT_SYMBOL_GPL(wf_find_control);

int wf_get_control(struct wf_control *ct)
{
	if (!try_module_get(ct->ops->owner))
		return -ENODEV;
	kref_get(&ct->ref);
	return 0;
}
EXPORT_SYMBOL_GPL(wf_get_control);

void wf_put_control(struct wf_control *ct)
{
	struct module *mod = ct->ops->owner;
	kref_put(&ct->ref, wf_control_release);
	module_put(mod);
}
EXPORT_SYMBOL_GPL(wf_put_control);


/*
 * Sensors
 */


static void wf_sensor_release(struct kref *kref)
{
	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);

	DBG("wf: Deleting sensor %s\n", sr->name);

	if (sr->ops && sr->ops->release)
		sr->ops->release(sr);
	else
		kfree(sr);
}

static ssize_t wf_show_sensor(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	s32 val = 0;
	int err;

	err = sens->ops->get_value(sens, &val);
	if (err < 0)
		return err;
	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
}

int wf_register_sensor(struct wf_sensor *new_sr)
{
	struct wf_sensor *sr;

	mutex_lock(&wf_lock);
	list_for_each_entry(sr, &wf_sensors, link) {
		if (!strcmp(sr->name, new_sr->name)) {
			printk(KERN_WARNING "windfarm: trying to register"
			       " duplicate sensor %s\n", sr->name);
			mutex_unlock(&wf_lock);
			return -EEXIST;
		}
	}
	kref_init(&new_sr->ref);
	list_add(&new_sr->link, &wf_sensors);

	new_sr->attr.attr.name = new_sr->name;
	new_sr->attr.attr.owner = THIS_MODULE;
	new_sr->attr.attr.mode = 0444;
	new_sr->attr.show = wf_show_sensor;
	new_sr->attr.store = NULL;
	device_create_file(&wf_platform_device.dev, &new_sr->attr);

	DBG("wf: Registered sensor %s\n", new_sr->name);

	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
	mutex_unlock(&wf_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(wf_register_sensor);

void wf_unregister_sensor(struct wf_sensor *sr)
{
	mutex_lock(&wf_lock);
	list_del(&sr->link);
	mutex_unlock(&wf_lock);

	DBG("wf: Unregistered sensor %s\n", sr->name);

	wf_put_sensor(sr);
}
EXPORT_SYMBOL_GPL(wf_unregister_sensor);

struct wf_sensor * wf_find_sensor(const char *name)
{
	struct wf_sensor *sr;

	mutex_lock(&wf_lock);
	list_for_each_entry(sr, &wf_sensors, link) {
		if (!strcmp(sr->name, name)) {
			if (wf_get_sensor(sr))
				sr = NULL;
			mutex_unlock(&wf_lock);
			return sr;
		}
	}
	mutex_unlock(&wf_lock);
	return NULL;
}
EXPORT_SYMBOL_GPL(wf_find_sensor);

int wf_get_sensor(struct wf_sensor *sr)
{
	if (!try_module_get(sr->ops->owner))
		return -ENODEV;
	kref_get(&sr->ref);
	return 0;
}
EXPORT_SYMBOL_GPL(wf_get_sensor);

void wf_put_sensor(struct wf_sensor *sr)
{
	struct module *mod = sr->ops->owner;
	kref_put(&sr->ref, wf_sensor_release);
	module_put(mod);
}
EXPORT_SYMBOL_GPL(wf_put_sensor);


/*
 * Client & notification
 */

int wf_register_client(struct notifier_block *nb)
{
	int rc;
	struct wf_control *ct;
	struct wf_sensor *sr;

	mutex_lock(&wf_lock);
	rc = blocking_notifier_chain_register(&wf_client_list, nb);
	if (rc != 0)
		goto bail;
	wf_client_count++;
	list_for_each_entry(ct, &wf_controls, link)
		wf_notify(WF_EVENT_NEW_CONTROL, ct);
	list_for_each_entry(sr, &wf_sensors, link)
		wf_notify(WF_EVENT_NEW_SENSOR, sr);
	if (wf_client_count == 1)
		wf_start_thread();
 bail:
	mutex_unlock(&wf_lock);
	return rc;
}
EXPORT_SYMBOL_GPL(wf_register_client);

int wf_unregister_client(struct notifier_block *nb)
{
	mutex_lock(&wf_lock);
	blocking_notifier_chain_unregister(&wf_client_list, nb);
	wf_client_count++;
	if (wf_client_count == 0)
		wf_stop_thread();
	mutex_unlock(&wf_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(wf_unregister_client);

void wf_set_overtemp(void)
{
	mutex_lock(&wf_lock);
	wf_overtemp++;
	if (wf_overtemp == 1) {
		printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
		wf_overtemp_counter = 0;
		wf_notify(WF_EVENT_OVERTEMP, NULL);
	}
	mutex_unlock(&wf_lock);
}
EXPORT_SYMBOL_GPL(wf_set_overtemp);

void wf_clear_overtemp(void)
{
	mutex_lock(&wf_lock);
	WARN_ON(wf_overtemp == 0);
	if (wf_overtemp == 0) {
		mutex_unlock(&wf_lock);
		return;
	}
	wf_overtemp--;
	if (wf_overtemp == 0) {
		printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
		wf_notify(WF_EVENT_NORMALTEMP, NULL);
	}
	mutex_unlock(&wf_lock);
}
EXPORT_SYMBOL_GPL(wf_clear_overtemp);

int wf_is_overtemp(void)
{
	return (wf_overtemp != 0);
}
EXPORT_SYMBOL_GPL(wf_is_overtemp);

static int __init windfarm_core_init(void)
{
	DBG("wf: core loaded\n");

	/* Don't register on old machines that use therm_pm72 for now */
	if (machine_is_compatible("PowerMac7,2") ||
	    machine_is_compatible("PowerMac7,3") ||
	    machine_is_compatible("RackMac3,1"))
		return -ENODEV;
	platform_device_register(&wf_platform_device);
	return 0;
}

static void __exit windfarm_core_exit(void)
{
	BUG_ON(wf_client_count != 0);

	DBG("wf: core unloaded\n");

	platform_device_unregister(&wf_platform_device);
}


module_init(windfarm_core_init);
module_exit(windfarm_core_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("Core component of PowerMac thermal control");
MODULE_LICENSE("GPL");
Commit	Line	Data
75722d39 BH	1	/*
	2	* Windfarm PowerMac thermal control. Core
	3	*
	4	* (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
	5	* <benh@kernel.crashing.org>
	6	*
	7	* Released under the term of the GNU GPL v2.
	8	*
	9	* This core code tracks the list of sensors & controls, register
	10	* clients, and holds the kernel thread used for control.
	11	*
	12	* TODO:
	13	*
	14	* Add some information about sensor/control type and data format to
	15	* sensors/controls, and have the sysfs attribute stuff be moved
	16	* generically here instead of hard coded in the platform specific
	17	* driver as it us currently
	18	*
	19	* This however requires solving some annoying lifetime issues with
	20	* sysfs which doesn't seem to have lifetime rules for struct attribute,
	21	* I may have to create full features kobjects for every sensor/control
	22	* instead which is a bit of an overkill imho
	23	*/
	24
	25	#include <linux/types.h>
	26	#include <linux/errno.h>
	27	#include <linux/kernel.h>
	28	#include <linux/init.h>
	29	#include <linux/spinlock.h>
	30	#include <linux/smp_lock.h>
	31	#include <linux/kthread.h>
	32	#include <linux/jiffies.h>
	33	#include <linux/reboot.h>
	34	#include <linux/device.h>
	35	#include <linux/platform_device.h>
837e9594	36	#include <linux/mutex.h>
7dfb7103	37	#include <linux/freezer.h>
75722d39	38
b55fafc5 BH	39	#include <asm/prom.h>
b55fafc5 BH	40
75722d39 BH	41	#include "windfarm.h"
	42
	43	#define VERSION "0.2"
	44
	45	#undef DEBUG
	46
	47	#ifdef DEBUG
	48	#define DBG(args...) printk(args)
	49	#else
	50	#define DBG(args...) do { } while(0)
	51	#endif
	52
	53	static LIST_HEAD(wf_controls);
	54	static LIST_HEAD(wf_sensors);
837e9594	55	static DEFINE_MUTEX(wf_lock);
e041c683	56	static BLOCKING_NOTIFIER_HEAD(wf_client_list);
75722d39 BH	57	static int wf_client_count;
	58	static unsigned int wf_overtemp;
	59	static unsigned int wf_overtemp_counter;
	60	struct task_struct *wf_thread;
	61
ac171c46 BH	62	static struct platform_device wf_platform_device = {
	63	.name = "windfarm",
	64	};
	65
75722d39 BH	66	/*
	67	* Utilities & tick thread
	68	*/
	69
	70	static inline void wf_notify(int event, void *param)
	71	{
e041c683	72	blocking_notifier_call_chain(&wf_client_list, event, param);
75722d39 BH	73	}
	74
	75	int wf_critical_overtemp(void)
	76	{
	77	static char * critical_overtemp_path = "/sbin/critical_overtemp";
	78	char *argv[] = { critical_overtemp_path, NULL };
	79	static char *envp[] = { "HOME=/",
	80	"TERM=linux",
	81	"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
	82	NULL };
	83
	84	return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
	85	}
	86	EXPORT_SYMBOL_GPL(wf_critical_overtemp);
	87
	88	static int wf_thread_func(void *data)
	89	{
	90	unsigned long next, delay;
	91
	92	next = jiffies;
	93
	94	DBG("wf: thread started\n");
	95
	96	while(!kthread_should_stop()) {
	97	try_to_freeze();
	98
	99	if (time_after_eq(jiffies, next)) {
	100	wf_notify(WF_EVENT_TICK, NULL);
	101	if (wf_overtemp) {
	102	wf_overtemp_counter++;
	103	/* 10 seconds overtemp, notify userland */
	104	if (wf_overtemp_counter > 10)
	105	wf_critical_overtemp();
	106	/* 30 seconds, shutdown */
	107	if (wf_overtemp_counter > 30) {
	108	printk(KERN_ERR "windfarm: Overtemp "
	109	"for more than 30"
	110	" seconds, shutting down\n");
	111	machine_power_off();
	112	}
	113	}
	114	next += HZ;
	115	}
	116
	117	delay = next - jiffies;
	118	if (delay <= HZ)
	119	schedule_timeout_interruptible(delay);
	120
	121	/* there should be no signal, but oh well */
	122	if (signal_pending(current)) {
	123	printk(KERN_WARNING "windfarm: thread got sigl !\n");
	124	break;
	125	}
	126	}
	127
	128	DBG("wf: thread stopped\n");
	129
	130	return 0;
	131	}
	132
	133	static void wf_start_thread(void)
	134	{
	135	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	136	if (IS_ERR(wf_thread)) {
137	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
138	PTR_ERR(wf_thread));
139	wf_thread = NULL;
140	}
141	}
142
143
144	static void wf_stop_thread(void)
145	{
146	if (wf_thread)
147	kthread_stop(wf_thread);
148	wf_thread = NULL;
149	}
150
151	/*
152	* Controls
153	*/
154
155	static void wf_control_release(struct kref *kref)
156	{
157	struct wf_control *ct = container_of(kref, struct wf_control, ref);
158
159	DBG("wf: Deleting control %s\n", ct->name);
160
161	if (ct->ops && ct->ops->release)
162	ct->ops->release(ct);
163	else
164	kfree(ct);
165	}
166
ac171c46 BH	167	static ssize_t wf_show_control(struct device *dev,
	168	struct device_attribute attr, char buf)
	169	{
	170	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	171	s32 val = 0;
	172	int err;
	173
	174	err = ctrl->ops->get_value(ctrl, &val);
	175	if (err < 0)
	176	return err;
	177	return sprintf(buf, "%d\n", val);
	178	}
	179
	180	/* This is really only for debugging... */
	181	static ssize_t wf_store_control(struct device *dev,
	182	struct device_attribute *attr,
	183	const char *buf, size_t count)
	184	{
	185	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	186	int val;
	187	int err;
	188	char *endp;
	189
	190	val = simple_strtoul(buf, &endp, 0);
	191	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	192	++endp;
	193	if (endp - buf < count)
	194	return -EINVAL;
	195	err = ctrl->ops->set_value(ctrl, val);
	196	if (err < 0)
	197	return err;
	198	return count;
	199	}
	200
75722d39 BH	201	int wf_register_control(struct wf_control *new_ct)
	202	{
	203	struct wf_control *ct;
	204
837e9594	205	mutex_lock(&wf_lock);
75722d39 BH	206	list_for_each_entry(ct, &wf_controls, link) {
	207	if (!strcmp(ct->name, new_ct->name)) {
	208	printk(KERN_WARNING "windfarm: trying to register"
	209	" duplicate control %s\n", ct->name);
837e9594	210	mutex_unlock(&wf_lock);
75722d39 BH	211	return -EEXIST;
	212	}
	213	}
	214	kref_init(&new_ct->ref);
	215	list_add(&new_ct->link, &wf_controls);
	216
ac171c46 BH	217	new_ct->attr.attr.name = new_ct->name;
	218	new_ct->attr.attr.owner = THIS_MODULE;
	219	new_ct->attr.attr.mode = 0644;
	220	new_ct->attr.show = wf_show_control;
	221	new_ct->attr.store = wf_store_control;
	222	device_create_file(&wf_platform_device.dev, &new_ct->attr);
	223
75722d39 BH	224	DBG("wf: Registered control %s\n", new_ct->name);
	225
	226	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	227	mutex_unlock(&wf_lock);
75722d39 BH	228
	229	return 0;
	230	}
	231	EXPORT_SYMBOL_GPL(wf_register_control);
	232
	233	void wf_unregister_control(struct wf_control *ct)
	234	{
837e9594	235	mutex_lock(&wf_lock);
75722d39	236	list_del(&ct->link);
837e9594	237	mutex_unlock(&wf_lock);
75722d39 BH	238
	239	DBG("wf: Unregistered control %s\n", ct->name);
	240
	241	kref_put(&ct->ref, wf_control_release);
	242	}
	243	EXPORT_SYMBOL_GPL(wf_unregister_control);
	244
	245	struct wf_control * wf_find_control(const char *name)
	246	{
	247	struct wf_control *ct;
	248
837e9594	249	mutex_lock(&wf_lock);
75722d39 BH	250	list_for_each_entry(ct, &wf_controls, link) {
	251	if (!strcmp(ct->name, name)) {
	252	if (wf_get_control(ct))
	253	ct = NULL;
837e9594	254	mutex_unlock(&wf_lock);
75722d39 BH	255	return ct;
	256	}
	257	}
837e9594	258	mutex_unlock(&wf_lock);
75722d39 BH	259	return NULL;
	260	}
	261	EXPORT_SYMBOL_GPL(wf_find_control);
	262
	263	int wf_get_control(struct wf_control *ct)
	264	{
	265	if (!try_module_get(ct->ops->owner))
	266	return -ENODEV;
	267	kref_get(&ct->ref);
	268	return 0;
	269	}
	270	EXPORT_SYMBOL_GPL(wf_get_control);
	271
	272	void wf_put_control(struct wf_control *ct)
	273	{
	274	struct module *mod = ct->ops->owner;
	275	kref_put(&ct->ref, wf_control_release);
	276	module_put(mod);
	277	}
	278	EXPORT_SYMBOL_GPL(wf_put_control);
	279
	280
	281	/*
	282	* Sensors
	283	*/
	284
	285
	286	static void wf_sensor_release(struct kref *kref)
	287	{
	288	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	289
	290	DBG("wf: Deleting sensor %s\n", sr->name);
	291
	292	if (sr->ops && sr->ops->release)
	293	sr->ops->release(sr);
	294	else
	295	kfree(sr);
	296	}
	297
ac171c46 BH	298	static ssize_t wf_show_sensor(struct device *dev,
	299	struct device_attribute attr, char buf)
	300	{
	301	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	302	s32 val = 0;
	303	int err;
	304
	305	err = sens->ops->get_value(sens, &val);
	306	if (err < 0)
	307	return err;
	308	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	309	}
	310
75722d39 BH	311	int wf_register_sensor(struct wf_sensor *new_sr)
	312	{
	313	struct wf_sensor *sr;
	314
837e9594	315	mutex_lock(&wf_lock);
75722d39 BH	316	list_for_each_entry(sr, &wf_sensors, link) {
	317	if (!strcmp(sr->name, new_sr->name)) {
	318	printk(KERN_WARNING "windfarm: trying to register"
	319	" duplicate sensor %s\n", sr->name);
837e9594	320	mutex_unlock(&wf_lock);
75722d39 BH	321	return -EEXIST;
	322	}
	323	}
	324	kref_init(&new_sr->ref);
	325	list_add(&new_sr->link, &wf_sensors);
	326
ac171c46 BH	327	new_sr->attr.attr.name = new_sr->name;
	328	new_sr->attr.attr.owner = THIS_MODULE;
	329	new_sr->attr.attr.mode = 0444;
	330	new_sr->attr.show = wf_show_sensor;
	331	new_sr->attr.store = NULL;
	332	device_create_file(&wf_platform_device.dev, &new_sr->attr);
	333
75722d39 BH	334	DBG("wf: Registered sensor %s\n", new_sr->name);
	335
	336	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	337	mutex_unlock(&wf_lock);
75722d39 BH	338
	339	return 0;
	340	}
	341	EXPORT_SYMBOL_GPL(wf_register_sensor);
	342
	343	void wf_unregister_sensor(struct wf_sensor *sr)
	344	{
837e9594	345	mutex_lock(&wf_lock);
75722d39	346	list_del(&sr->link);
837e9594	347	mutex_unlock(&wf_lock);
75722d39 BH	348
	349	DBG("wf: Unregistered sensor %s\n", sr->name);
	350
	351	wf_put_sensor(sr);
	352	}
	353	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	354
	355	struct wf_sensor * wf_find_sensor(const char *name)
	356	{
	357	struct wf_sensor *sr;
	358
837e9594	359	mutex_lock(&wf_lock);
75722d39 BH	360	list_for_each_entry(sr, &wf_sensors, link) {
	361	if (!strcmp(sr->name, name)) {
	362	if (wf_get_sensor(sr))
	363	sr = NULL;
837e9594	364	mutex_unlock(&wf_lock);
75722d39 BH	365	return sr;
	366	}
	367	}
837e9594	368	mutex_unlock(&wf_lock);
75722d39 BH	369	return NULL;
	370	}
	371	EXPORT_SYMBOL_GPL(wf_find_sensor);
	372
	373	int wf_get_sensor(struct wf_sensor *sr)
	374	{
	375	if (!try_module_get(sr->ops->owner))
	376	return -ENODEV;
	377	kref_get(&sr->ref);
	378	return 0;
	379	}
	380	EXPORT_SYMBOL_GPL(wf_get_sensor);
	381
	382	void wf_put_sensor(struct wf_sensor *sr)
	383	{
	384	struct module *mod = sr->ops->owner;
	385	kref_put(&sr->ref, wf_sensor_release);
	386	module_put(mod);
	387	}
	388	EXPORT_SYMBOL_GPL(wf_put_sensor);
	389
	390
	391	/*
	392	* Client & notification
	393	*/
	394
	395	int wf_register_client(struct notifier_block *nb)
	396	{
	397	int rc;
	398	struct wf_control *ct;
	399	struct wf_sensor *sr;
	400
837e9594	401	mutex_lock(&wf_lock);
e041c683	402	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	403	if (rc != 0)
	404	goto bail;
	405	wf_client_count++;
	406	list_for_each_entry(ct, &wf_controls, link)
	407	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	408	list_for_each_entry(sr, &wf_sensors, link)
	409	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	410	if (wf_client_count == 1)
	411	wf_start_thread();
	412	bail:
837e9594	413	mutex_unlock(&wf_lock);
75722d39 BH	414	return rc;
	415	}
	416	EXPORT_SYMBOL_GPL(wf_register_client);
	417
	418	int wf_unregister_client(struct notifier_block *nb)
	419	{
837e9594	420	mutex_lock(&wf_lock);
e041c683	421	blocking_notifier_chain_unregister(&wf_client_list, nb);
75722d39 BH	422	wf_client_count++;
	423	if (wf_client_count == 0)
	424	wf_stop_thread();
837e9594	425	mutex_unlock(&wf_lock);
75722d39 BH	426
	427	return 0;
	428	}
	429	EXPORT_SYMBOL_GPL(wf_unregister_client);
	430
	431	void wf_set_overtemp(void)
	432	{
837e9594	433	mutex_lock(&wf_lock);
75722d39 BH	434	wf_overtemp++;
	435	if (wf_overtemp == 1) {
	436	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	437	wf_overtemp_counter = 0;
	438	wf_notify(WF_EVENT_OVERTEMP, NULL);
	439	}
837e9594	440	mutex_unlock(&wf_lock);
75722d39 BH	441	}
	442	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	443
	444	void wf_clear_overtemp(void)
	445	{
837e9594	446	mutex_lock(&wf_lock);
75722d39 BH	447	WARN_ON(wf_overtemp == 0);
75722d39 BH	448	if (wf_overtemp == 0) {
837e9594	449	mutex_unlock(&wf_lock);
75722d39 BH	450	return;
	451	}
	452	wf_overtemp--;
	453	if (wf_overtemp == 0) {
	454	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	455	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	456	}
837e9594	457	mutex_unlock(&wf_lock);
75722d39 BH	458	}
	459	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	460
	461	int wf_is_overtemp(void)
	462	{
	463	return (wf_overtemp != 0);
	464	}
	465	EXPORT_SYMBOL_GPL(wf_is_overtemp);
	466
75722d39 BH	467	static int __init windfarm_core_init(void)
	468	{
	469	DBG("wf: core loaded\n");
	470
b55fafc5 BH	471	/* Don't register on old machines that use therm_pm72 for now */
	472	if (machine_is_compatible("PowerMac7,2") \|\|
	473	machine_is_compatible("PowerMac7,3") \|\|
	474	machine_is_compatible("RackMac3,1"))
	475	return -ENODEV;
75722d39 BH	476	platform_device_register(&wf_platform_device);
	477	return 0;
	478	}
	479
	480	static void __exit windfarm_core_exit(void)
	481	{
	482	BUG_ON(wf_client_count != 0);
	483
	484	DBG("wf: core unloaded\n");
	485
	486	platform_device_unregister(&wf_platform_device);
	487	}
	488
	489
	490	module_init(windfarm_core_init);
	491	module_exit(windfarm_core_exit);
	492
	493	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	494	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	495	MODULE_LICENSE("GPL");
	496