[mirror_ubuntu-bionic-kernel.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/slab.h>
#include <linux/init.h>
#include <linux/spinlock.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);
}

static int wf_critical_overtemp(void)
{
	static char const critical_overtemp_path[] = "/sbin/critical_overtemp";
	char *argv[] = { (char *)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, UMH_WAIT_EXEC);
}

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

	next = jiffies;

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

	set_freezable();
	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);
	}

	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);
	const char *typestr;
	s32 val = 0;
	int err;

	err = ctrl->ops->get_value(ctrl, &val);
	if (err < 0) {
		if (err == -EFAULT)
			return sprintf(buf, "<HW FAULT>\n");
		return err;
	}
	switch(ctrl->type) {
	case WF_CONTROL_RPM_FAN:
		typestr = " RPM";
		break;
	case WF_CONTROL_PWM_FAN:
		typestr = " %";
		break;
	default:
		typestr = "";
	}
	return sprintf(buf, "%d%s\n", val, typestr);
}

/* 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);

	sysfs_attr_init(&new_ct->attr.attr);
	new_ct->attr.attr.name = new_ct->name;
	new_ct->attr.attr.mode = 0644;
	new_ct->attr.show = wf_show_control;
	new_ct->attr.store = wf_store_control;
	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
		printk(KERN_WARNING "windfarm: device_create_file failed"
			" for %s\n", new_ct->name);
		/* the subsystem still does useful work without the file */

	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);

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);

	sysfs_attr_init(&new_sr->attr.attr);
	new_sr->attr.attr.name = new_sr->name;
	new_sr->attr.attr.mode = 0444;
	new_sr->attr.show = wf_show_sensor;
	new_sr->attr.store = NULL;
	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
		printk(KERN_WARNING "windfarm: device_create_file failed"
			" for %s\n", new_sr->name);
		/* the subsystem still does useful work without the file */

	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);

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);

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

	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>
5a0e3ad6	28	#include <linux/slab.h>
75722d39 BH	29	#include <linux/init.h>
75722d39 BH	30	#include <linux/spinlock.h>
75722d39 BH	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	}
75722d39 BH	74
ca94bbab	75	static int wf_critical_overtemp(void)
75722d39	76	{
377e7a27 GKH	77	static char const critical_overtemp_path[] = "/sbin/critical_overtemp";
377e7a27 GKH	78	char argv[] = { (char )critical_overtemp_path, NULL };
75722d39 BH	79	static char *envp[] = { "HOME=/",
	80	"TERM=linux",
	81	"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
	82	NULL };
	83
86313c48 JF	84	return call_usermodehelper(critical_overtemp_path,
86313c48 JF	85	argv, envp, UMH_WAIT_EXEC);
75722d39	86	}
75722d39 BH	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
83144186	96	set_freezable();
67b60518 JB	97	while (!kthread_should_stop()) {
	98	try_to_freeze();
	99
75722d39 BH	100	if (time_after_eq(jiffies, next)) {
	101	wf_notify(WF_EVENT_TICK, NULL);
	102	if (wf_overtemp) {
	103	wf_overtemp_counter++;
	104	/* 10 seconds overtemp, notify userland */
	105	if (wf_overtemp_counter > 10)
	106	wf_critical_overtemp();
	107	/* 30 seconds, shutdown */
	108	if (wf_overtemp_counter > 30) {
	109	printk(KERN_ERR "windfarm: Overtemp "
	110	"for more than 30"
	111	" seconds, shutting down\n");
	112	machine_power_off();
	113	}
	114	}
	115	next += HZ;
	116	}
	117
	118	delay = next - jiffies;
	119	if (delay <= HZ)
	120	schedule_timeout_interruptible(delay);
75722d39 BH	121	}
	122
	123	DBG("wf: thread stopped\n");
	124
	125	return 0;
	126	}
	127
	128	static void wf_start_thread(void)
	129	{
	130	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	131	if (IS_ERR(wf_thread)) {
	132	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
	133	PTR_ERR(wf_thread));
	134	wf_thread = NULL;
	135	}
	136	}
	137
	138
	139	static void wf_stop_thread(void)
	140	{
	141	if (wf_thread)
	142	kthread_stop(wf_thread);
	143	wf_thread = NULL;
	144	}
	145
	146	/*
	147	* Controls
	148	*/
	149
	150	static void wf_control_release(struct kref *kref)
	151	{
	152	struct wf_control *ct = container_of(kref, struct wf_control, ref);
	153
	154	DBG("wf: Deleting control %s\n", ct->name);
	155
	156	if (ct->ops && ct->ops->release)
	157	ct->ops->release(ct);
	158	else
	159	kfree(ct);
	160	}
	161
ac171c46 BH	162	static ssize_t wf_show_control(struct device *dev,
	163	struct device_attribute attr, char buf)
	164	{
	165	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
ea5c64b0	166	const char *typestr;
ac171c46 BH	167	s32 val = 0;
	168	int err;
	169
	170	err = ctrl->ops->get_value(ctrl, &val);
6cd32099 BH	171	if (err < 0) {
	172	if (err == -EFAULT)
	173	return sprintf(buf, "<HW FAULT>\n");
ac171c46	174	return err;
6cd32099	175	}
ea5c64b0 BH	176	switch(ctrl->type) {
	177	case WF_CONTROL_RPM_FAN:
	178	typestr = " RPM";
	179	break;
	180	case WF_CONTROL_PWM_FAN:
	181	typestr = " %";
	182	break;
	183	default:
	184	typestr = "";
	185	}
	186	return sprintf(buf, "%d%s\n", val, typestr);
ac171c46 BH	187	}
	188
	189	/* This is really only for debugging... */
	190	static ssize_t wf_store_control(struct device *dev,
	191	struct device_attribute *attr,
	192	const char *buf, size_t count)
	193	{
	194	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	195	int val;
	196	int err;
	197	char *endp;
	198
	199	val = simple_strtoul(buf, &endp, 0);
	200	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	201	++endp;
	202	if (endp - buf < count)
	203	return -EINVAL;
	204	err = ctrl->ops->set_value(ctrl, val);
	205	if (err < 0)
	206	return err;
	207	return count;
	208	}
	209
75722d39 BH	210	int wf_register_control(struct wf_control *new_ct)
	211	{
	212	struct wf_control *ct;
	213
837e9594	214	mutex_lock(&wf_lock);
75722d39 BH	215	list_for_each_entry(ct, &wf_controls, link) {
	216	if (!strcmp(ct->name, new_ct->name)) {
	217	printk(KERN_WARNING "windfarm: trying to register"
	218	" duplicate control %s\n", ct->name);
837e9594	219	mutex_unlock(&wf_lock);
75722d39 BH	220	return -EEXIST;
	221	}
	222	}
	223	kref_init(&new_ct->ref);
	224	list_add(&new_ct->link, &wf_controls);
	225
12765517	226	sysfs_attr_init(&new_ct->attr.attr);
ac171c46	227	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	228	new_ct->attr.attr.mode = 0644;
	229	new_ct->attr.show = wf_show_control;
	230	new_ct->attr.store = wf_store_control;
ccd308f0 SR	231	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	232	printk(KERN_WARNING "windfarm: device_create_file failed"
	233	" for %s\n", new_ct->name);
	234	/* the subsystem still does useful work without the file */
ac171c46	235
75722d39 BH	236	DBG("wf: Registered control %s\n", new_ct->name);
	237
	238	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	239	mutex_unlock(&wf_lock);
75722d39 BH	240
	241	return 0;
	242	}
	243	EXPORT_SYMBOL_GPL(wf_register_control);
	244
	245	void wf_unregister_control(struct wf_control *ct)
	246	{
837e9594	247	mutex_lock(&wf_lock);
75722d39	248	list_del(&ct->link);
837e9594	249	mutex_unlock(&wf_lock);
75722d39 BH	250
	251	DBG("wf: Unregistered control %s\n", ct->name);
	252
	253	kref_put(&ct->ref, wf_control_release);
	254	}
	255	EXPORT_SYMBOL_GPL(wf_unregister_control);
	256
75722d39 BH	257	int wf_get_control(struct wf_control *ct)
	258	{
	259	if (!try_module_get(ct->ops->owner))
	260	return -ENODEV;
	261	kref_get(&ct->ref);
	262	return 0;
	263	}
	264	EXPORT_SYMBOL_GPL(wf_get_control);
	265
	266	void wf_put_control(struct wf_control *ct)
	267	{
	268	struct module *mod = ct->ops->owner;
	269	kref_put(&ct->ref, wf_control_release);
	270	module_put(mod);
	271	}
	272	EXPORT_SYMBOL_GPL(wf_put_control);
	273
	274
	275	/*
	276	* Sensors
	277	*/
	278
	279
	280	static void wf_sensor_release(struct kref *kref)
	281	{
	282	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	283
	284	DBG("wf: Deleting sensor %s\n", sr->name);
	285
	286	if (sr->ops && sr->ops->release)
	287	sr->ops->release(sr);
	288	else
	289	kfree(sr);
	290	}
	291
ac171c46 BH	292	static ssize_t wf_show_sensor(struct device *dev,
	293	struct device_attribute attr, char buf)
	294	{
	295	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	296	s32 val = 0;
	297	int err;
	298
	299	err = sens->ops->get_value(sens, &val);
	300	if (err < 0)
	301	return err;
	302	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	303	}
	304
75722d39 BH	305	int wf_register_sensor(struct wf_sensor *new_sr)
	306	{
	307	struct wf_sensor *sr;
	308
837e9594	309	mutex_lock(&wf_lock);
75722d39 BH	310	list_for_each_entry(sr, &wf_sensors, link) {
	311	if (!strcmp(sr->name, new_sr->name)) {
	312	printk(KERN_WARNING "windfarm: trying to register"
	313	" duplicate sensor %s\n", sr->name);
837e9594	314	mutex_unlock(&wf_lock);
75722d39 BH	315	return -EEXIST;
	316	}
	317	}
	318	kref_init(&new_sr->ref);
	319	list_add(&new_sr->link, &wf_sensors);
	320
b35c74da	321	sysfs_attr_init(&new_sr->attr.attr);
ac171c46	322	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	323	new_sr->attr.attr.mode = 0444;
	324	new_sr->attr.show = wf_show_sensor;
	325	new_sr->attr.store = NULL;
ccd308f0 SR	326	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	327	printk(KERN_WARNING "windfarm: device_create_file failed"
	328	" for %s\n", new_sr->name);
	329	/* the subsystem still does useful work without the file */
ac171c46	330
75722d39 BH	331	DBG("wf: Registered sensor %s\n", new_sr->name);
	332
	333	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	334	mutex_unlock(&wf_lock);
75722d39 BH	335
	336	return 0;
	337	}
	338	EXPORT_SYMBOL_GPL(wf_register_sensor);
	339
	340	void wf_unregister_sensor(struct wf_sensor *sr)
	341	{
837e9594	342	mutex_lock(&wf_lock);
75722d39	343	list_del(&sr->link);
837e9594	344	mutex_unlock(&wf_lock);
75722d39 BH	345
	346	DBG("wf: Unregistered sensor %s\n", sr->name);
	347
	348	wf_put_sensor(sr);
	349	}
	350	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	351
75722d39 BH	352	int wf_get_sensor(struct wf_sensor *sr)
	353	{
	354	if (!try_module_get(sr->ops->owner))
	355	return -ENODEV;
	356	kref_get(&sr->ref);
	357	return 0;
	358	}
	359	EXPORT_SYMBOL_GPL(wf_get_sensor);
	360
	361	void wf_put_sensor(struct wf_sensor *sr)
	362	{
	363	struct module *mod = sr->ops->owner;
	364	kref_put(&sr->ref, wf_sensor_release);
	365	module_put(mod);
	366	}
	367	EXPORT_SYMBOL_GPL(wf_put_sensor);
	368
	369
	370	/*
	371	* Client & notification
	372	*/
	373
	374	int wf_register_client(struct notifier_block *nb)
	375	{
	376	int rc;
	377	struct wf_control *ct;
	378	struct wf_sensor *sr;
	379
837e9594	380	mutex_lock(&wf_lock);
e041c683	381	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	382	if (rc != 0)
	383	goto bail;
	384	wf_client_count++;
	385	list_for_each_entry(ct, &wf_controls, link)
	386	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	387	list_for_each_entry(sr, &wf_sensors, link)
	388	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	389	if (wf_client_count == 1)
	390	wf_start_thread();
	391	bail:
837e9594	392	mutex_unlock(&wf_lock);
75722d39 BH	393	return rc;
	394	}
	395	EXPORT_SYMBOL_GPL(wf_register_client);
	396
	397	int wf_unregister_client(struct notifier_block *nb)
	398	{
837e9594	399	mutex_lock(&wf_lock);
e041c683	400	blocking_notifier_chain_unregister(&wf_client_list, nb);
fe2b5921	401	wf_client_count--;
75722d39 BH	402	if (wf_client_count == 0)
75722d39 BH	403	wf_stop_thread();
837e9594	404	mutex_unlock(&wf_lock);
75722d39 BH	405
	406	return 0;
	407	}
	408	EXPORT_SYMBOL_GPL(wf_unregister_client);
	409
	410	void wf_set_overtemp(void)
	411	{
837e9594	412	mutex_lock(&wf_lock);
75722d39 BH	413	wf_overtemp++;
	414	if (wf_overtemp == 1) {
	415	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	416	wf_overtemp_counter = 0;
	417	wf_notify(WF_EVENT_OVERTEMP, NULL);
	418	}
837e9594	419	mutex_unlock(&wf_lock);
75722d39 BH	420	}
	421	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	422
	423	void wf_clear_overtemp(void)
	424	{
837e9594	425	mutex_lock(&wf_lock);
75722d39 BH	426	WARN_ON(wf_overtemp == 0);
75722d39 BH	427	if (wf_overtemp == 0) {
837e9594	428	mutex_unlock(&wf_lock);
75722d39 BH	429	return;
	430	}
	431	wf_overtemp--;
	432	if (wf_overtemp == 0) {
	433	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	434	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	435	}
837e9594	436	mutex_unlock(&wf_lock);
75722d39 BH	437	}
	438	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	439
75722d39 BH	440	static int __init windfarm_core_init(void)
	441	{
	442	DBG("wf: core loaded\n");
	443
	444	platform_device_register(&wf_platform_device);
	445	return 0;
	446	}
	447
	448	static void __exit windfarm_core_exit(void)
	449	{
	450	BUG_ON(wf_client_count != 0);
	451
	452	DBG("wf: core unloaded\n");
	453
	454	platform_device_unregister(&wf_platform_device);
	455	}
	456
	457
	458	module_init(windfarm_core_init);
	459	module_exit(windfarm_core_exit);
	460
	461	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	462	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	463	MODULE_LICENSE("GPL");
	464