[GitHub/mt8127/android_kernel_alcatel_ttab.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/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, UMH_WAIT_EXEC);
}
EXPORT_SYMBOL_GPL(wf_critical_overtemp);

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);
	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.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);

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);

	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);

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 (of_machine_is_compatible("PowerMac7,2") ||
	    of_machine_is_compatible("PowerMac7,3") ||
	    of_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>
75722d39 BH	30	#include <linux/kthread.h>
	31	#include <linux/jiffies.h>
	32	#include <linux/reboot.h>
	33	#include <linux/device.h>
	34	#include <linux/platform_device.h>
837e9594	35	#include <linux/mutex.h>
7dfb7103	36	#include <linux/freezer.h>
75722d39	37
b55fafc5 BH	38	#include <asm/prom.h>
b55fafc5 BH	39
75722d39 BH	40	#include "windfarm.h"
	41
	42	#define VERSION "0.2"
	43
	44	#undef DEBUG
	45
	46	#ifdef DEBUG
	47	#define DBG(args...) printk(args)
	48	#else
	49	#define DBG(args...) do { } while(0)
	50	#endif
	51
	52	static LIST_HEAD(wf_controls);
	53	static LIST_HEAD(wf_sensors);
837e9594	54	static DEFINE_MUTEX(wf_lock);
e041c683	55	static BLOCKING_NOTIFIER_HEAD(wf_client_list);
75722d39 BH	56	static int wf_client_count;
	57	static unsigned int wf_overtemp;
	58	static unsigned int wf_overtemp_counter;
	59	struct task_struct *wf_thread;
	60
ac171c46 BH	61	static struct platform_device wf_platform_device = {
	62	.name = "windfarm",
	63	};
	64
75722d39 BH	65	/*
	66	* Utilities & tick thread
	67	*/
	68
	69	static inline void wf_notify(int event, void *param)
	70	{
e041c683	71	blocking_notifier_call_chain(&wf_client_list, event, param);
75722d39 BH	72	}
	73
	74	int wf_critical_overtemp(void)
	75	{
	76	static char * critical_overtemp_path = "/sbin/critical_overtemp";
	77	char *argv[] = { critical_overtemp_path, NULL };
	78	static char *envp[] = { "HOME=/",
	79	"TERM=linux",
	80	"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
	81	NULL };
	82
86313c48 JF	83	return call_usermodehelper(critical_overtemp_path,
86313c48 JF	84	argv, envp, UMH_WAIT_EXEC);
75722d39 BH	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
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);
	166	s32 val = 0;
	167	int err;
	168
	169	err = ctrl->ops->get_value(ctrl, &val);
	170	if (err < 0)
	171	return err;
	172	return sprintf(buf, "%d\n", val);
	173	}
	174
	175	/* This is really only for debugging... */
	176	static ssize_t wf_store_control(struct device *dev,
	177	struct device_attribute *attr,
	178	const char *buf, size_t count)
	179	{
	180	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	181	int val;
	182	int err;
	183	char *endp;
	184
	185	val = simple_strtoul(buf, &endp, 0);
	186	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	187	++endp;
	188	if (endp - buf < count)
	189	return -EINVAL;
	190	err = ctrl->ops->set_value(ctrl, val);
	191	if (err < 0)
	192	return err;
	193	return count;
	194	}
	195
75722d39 BH	196	int wf_register_control(struct wf_control *new_ct)
	197	{
	198	struct wf_control *ct;
	199
837e9594	200	mutex_lock(&wf_lock);
75722d39 BH	201	list_for_each_entry(ct, &wf_controls, link) {
	202	if (!strcmp(ct->name, new_ct->name)) {
	203	printk(KERN_WARNING "windfarm: trying to register"
	204	" duplicate control %s\n", ct->name);
837e9594	205	mutex_unlock(&wf_lock);
75722d39 BH	206	return -EEXIST;
	207	}
	208	}
	209	kref_init(&new_ct->ref);
	210	list_add(&new_ct->link, &wf_controls);
	211
ac171c46	212	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	213	new_ct->attr.attr.mode = 0644;
	214	new_ct->attr.show = wf_show_control;
	215	new_ct->attr.store = wf_store_control;
ccd308f0 SR	216	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	217	printk(KERN_WARNING "windfarm: device_create_file failed"
	218	" for %s\n", new_ct->name);
	219	/* the subsystem still does useful work without the file */
ac171c46	220
75722d39 BH	221	DBG("wf: Registered control %s\n", new_ct->name);
	222
	223	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	224	mutex_unlock(&wf_lock);
75722d39 BH	225
	226	return 0;
	227	}
	228	EXPORT_SYMBOL_GPL(wf_register_control);
	229
	230	void wf_unregister_control(struct wf_control *ct)
	231	{
837e9594	232	mutex_lock(&wf_lock);
75722d39	233	list_del(&ct->link);
837e9594	234	mutex_unlock(&wf_lock);
75722d39 BH	235
	236	DBG("wf: Unregistered control %s\n", ct->name);
	237
	238	kref_put(&ct->ref, wf_control_release);
	239	}
	240	EXPORT_SYMBOL_GPL(wf_unregister_control);
	241
	242	struct wf_control * wf_find_control(const char *name)
	243	{
	244	struct wf_control *ct;
	245
837e9594	246	mutex_lock(&wf_lock);
75722d39 BH	247	list_for_each_entry(ct, &wf_controls, link) {
	248	if (!strcmp(ct->name, name)) {
	249	if (wf_get_control(ct))
	250	ct = NULL;
837e9594	251	mutex_unlock(&wf_lock);
75722d39 BH	252	return ct;
	253	}
	254	}
837e9594	255	mutex_unlock(&wf_lock);
75722d39 BH	256	return NULL;
	257	}
	258	EXPORT_SYMBOL_GPL(wf_find_control);
	259
	260	int wf_get_control(struct wf_control *ct)
	261	{
	262	if (!try_module_get(ct->ops->owner))
	263	return -ENODEV;
	264	kref_get(&ct->ref);
	265	return 0;
	266	}
	267	EXPORT_SYMBOL_GPL(wf_get_control);
	268
	269	void wf_put_control(struct wf_control *ct)
	270	{
	271	struct module *mod = ct->ops->owner;
	272	kref_put(&ct->ref, wf_control_release);
	273	module_put(mod);
	274	}
	275	EXPORT_SYMBOL_GPL(wf_put_control);
	276
	277
	278	/*
	279	* Sensors
	280	*/
	281
	282
	283	static void wf_sensor_release(struct kref *kref)
	284	{
	285	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	286
	287	DBG("wf: Deleting sensor %s\n", sr->name);
	288
	289	if (sr->ops && sr->ops->release)
	290	sr->ops->release(sr);
	291	else
	292	kfree(sr);
	293	}
	294
ac171c46 BH	295	static ssize_t wf_show_sensor(struct device *dev,
	296	struct device_attribute attr, char buf)
	297	{
	298	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	299	s32 val = 0;
	300	int err;
	301
	302	err = sens->ops->get_value(sens, &val);
	303	if (err < 0)
	304	return err;
	305	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	306	}
	307
75722d39 BH	308	int wf_register_sensor(struct wf_sensor *new_sr)
	309	{
	310	struct wf_sensor *sr;
	311
837e9594	312	mutex_lock(&wf_lock);
75722d39 BH	313	list_for_each_entry(sr, &wf_sensors, link) {
	314	if (!strcmp(sr->name, new_sr->name)) {
	315	printk(KERN_WARNING "windfarm: trying to register"
	316	" duplicate sensor %s\n", sr->name);
837e9594	317	mutex_unlock(&wf_lock);
75722d39 BH	318	return -EEXIST;
	319	}
	320	}
	321	kref_init(&new_sr->ref);
	322	list_add(&new_sr->link, &wf_sensors);
	323
b35c74da	324	sysfs_attr_init(&new_sr->attr.attr);
ac171c46	325	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	326	new_sr->attr.attr.mode = 0444;
	327	new_sr->attr.show = wf_show_sensor;
	328	new_sr->attr.store = NULL;
ccd308f0 SR	329	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	330	printk(KERN_WARNING "windfarm: device_create_file failed"
	331	" for %s\n", new_sr->name);
	332	/* the subsystem still does useful work without the file */
ac171c46	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	471	/* Don't register on old machines that use therm_pm72 for now */
71a157e8 GL	472	if (of_machine_is_compatible("PowerMac7,2") \|\|
	473	of_machine_is_compatible("PowerMac7,3") \|\|
	474	of_machine_is_compatible("RackMac3,1"))
b55fafc5	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