[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/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()) {
		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 non-suspend signal, but oh well */
		if (signal_pending(current) && !try_to_freeze()) {
			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.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);

	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 (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>
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();
75722d39	97	while(!kthread_should_stop()) {
75722d39 BH	98	if (time_after_eq(jiffies, next)) {
	99	wf_notify(WF_EVENT_TICK, NULL);
	100	if (wf_overtemp) {
	101	wf_overtemp_counter++;
	102	/* 10 seconds overtemp, notify userland */
	103	if (wf_overtemp_counter > 10)
	104	wf_critical_overtemp();
	105	/* 30 seconds, shutdown */
	106	if (wf_overtemp_counter > 30) {
	107	printk(KERN_ERR "windfarm: Overtemp "
	108	"for more than 30"
	109	" seconds, shutting down\n");
	110	machine_power_off();
	111	}
	112	}
	113	next += HZ;
	114	}
	115
	116	delay = next - jiffies;
	117	if (delay <= HZ)
	118	schedule_timeout_interruptible(delay);
	119
1ed2ddf3 JB	120	/* there should be no non-suspend signal, but oh well */
1ed2ddf3 JB	121	if (signal_pending(current) && !try_to_freeze()) {
75722d39 BH	122	printk(KERN_WARNING "windfarm: thread got sigl !\n");
	123	break;
	124	}
	125	}
	126
	127	DBG("wf: thread stopped\n");
	128
	129	return 0;
	130	}
	131
	132	static void wf_start_thread(void)
	133	{
	134	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	135	if (IS_ERR(wf_thread)) {
	136	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
	137	PTR_ERR(wf_thread));
	138	wf_thread = NULL;
	139	}
	140	}
	141
	142
	143	static void wf_stop_thread(void)
	144	{
	145	if (wf_thread)
	146	kthread_stop(wf_thread);
	147	wf_thread = NULL;
	148	}
	149
	150	/*
	151	* Controls
	152	*/
	153
	154	static void wf_control_release(struct kref *kref)
	155	{
	156	struct wf_control *ct = container_of(kref, struct wf_control, ref);
	157
	158	DBG("wf: Deleting control %s\n", ct->name);
	159
	160	if (ct->ops && ct->ops->release)
	161	ct->ops->release(ct);
	162	else
	163	kfree(ct);
	164	}
	165
ac171c46 BH	166	static ssize_t wf_show_control(struct device *dev,
	167	struct device_attribute attr, char buf)
	168	{
	169	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	170	s32 val = 0;
	171	int err;
	172
	173	err = ctrl->ops->get_value(ctrl, &val);
	174	if (err < 0)
	175	return err;
	176	return sprintf(buf, "%d\n", val);
	177	}
	178
	179	/* This is really only for debugging... */
	180	static ssize_t wf_store_control(struct device *dev,
	181	struct device_attribute *attr,
	182	const char *buf, size_t count)
	183	{
	184	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	185	int val;
	186	int err;
	187	char *endp;
	188
	189	val = simple_strtoul(buf, &endp, 0);
	190	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	191	++endp;
	192	if (endp - buf < count)
	193	return -EINVAL;
	194	err = ctrl->ops->set_value(ctrl, val);
	195	if (err < 0)
	196	return err;
	197	return count;
	198	}
	199
75722d39 BH	200	int wf_register_control(struct wf_control *new_ct)
	201	{
	202	struct wf_control *ct;
	203
837e9594	204	mutex_lock(&wf_lock);
75722d39 BH	205	list_for_each_entry(ct, &wf_controls, link) {
	206	if (!strcmp(ct->name, new_ct->name)) {
	207	printk(KERN_WARNING "windfarm: trying to register"
	208	" duplicate control %s\n", ct->name);
837e9594	209	mutex_unlock(&wf_lock);
75722d39 BH	210	return -EEXIST;
	211	}
	212	}
	213	kref_init(&new_ct->ref);
	214	list_add(&new_ct->link, &wf_controls);
	215
ac171c46	216	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	217	new_ct->attr.attr.mode = 0644;
	218	new_ct->attr.show = wf_show_control;
	219	new_ct->attr.store = wf_store_control;
ccd308f0 SR	220	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	221	printk(KERN_WARNING "windfarm: device_create_file failed"
	222	" for %s\n", new_ct->name);
	223	/* the subsystem still does useful work without the file */
ac171c46	224
75722d39 BH	225	DBG("wf: Registered control %s\n", new_ct->name);
	226
	227	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	228	mutex_unlock(&wf_lock);
75722d39 BH	229
	230	return 0;
	231	}
	232	EXPORT_SYMBOL_GPL(wf_register_control);
	233
	234	void wf_unregister_control(struct wf_control *ct)
	235	{
837e9594	236	mutex_lock(&wf_lock);
75722d39	237	list_del(&ct->link);
837e9594	238	mutex_unlock(&wf_lock);
75722d39 BH	239
	240	DBG("wf: Unregistered control %s\n", ct->name);
	241
	242	kref_put(&ct->ref, wf_control_release);
	243	}
	244	EXPORT_SYMBOL_GPL(wf_unregister_control);
	245
	246	struct wf_control * wf_find_control(const char *name)
	247	{
	248	struct wf_control *ct;
	249
837e9594	250	mutex_lock(&wf_lock);
75722d39 BH	251	list_for_each_entry(ct, &wf_controls, link) {
	252	if (!strcmp(ct->name, name)) {
	253	if (wf_get_control(ct))
	254	ct = NULL;
837e9594	255	mutex_unlock(&wf_lock);
75722d39 BH	256	return ct;
	257	}
	258	}
837e9594	259	mutex_unlock(&wf_lock);
75722d39 BH	260	return NULL;
	261	}
	262	EXPORT_SYMBOL_GPL(wf_find_control);
	263
	264	int wf_get_control(struct wf_control *ct)
	265	{
	266	if (!try_module_get(ct->ops->owner))
	267	return -ENODEV;
	268	kref_get(&ct->ref);
	269	return 0;
	270	}
	271	EXPORT_SYMBOL_GPL(wf_get_control);
	272
	273	void wf_put_control(struct wf_control *ct)
	274	{
	275	struct module *mod = ct->ops->owner;
	276	kref_put(&ct->ref, wf_control_release);
	277	module_put(mod);
	278	}
	279	EXPORT_SYMBOL_GPL(wf_put_control);
	280
	281
	282	/*
	283	* Sensors
	284	*/
	285
	286
	287	static void wf_sensor_release(struct kref *kref)
	288	{
	289	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	290
	291	DBG("wf: Deleting sensor %s\n", sr->name);
	292
	293	if (sr->ops && sr->ops->release)
	294	sr->ops->release(sr);
	295	else
	296	kfree(sr);
	297	}
	298
ac171c46 BH	299	static ssize_t wf_show_sensor(struct device *dev,
	300	struct device_attribute attr, char buf)
	301	{
	302	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	303	s32 val = 0;
	304	int err;
	305
	306	err = sens->ops->get_value(sens, &val);
	307	if (err < 0)
	308	return err;
	309	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	310	}
	311
75722d39 BH	312	int wf_register_sensor(struct wf_sensor *new_sr)
	313	{
	314	struct wf_sensor *sr;
	315
837e9594	316	mutex_lock(&wf_lock);
75722d39 BH	317	list_for_each_entry(sr, &wf_sensors, link) {
	318	if (!strcmp(sr->name, new_sr->name)) {
	319	printk(KERN_WARNING "windfarm: trying to register"
	320	" duplicate sensor %s\n", sr->name);
837e9594	321	mutex_unlock(&wf_lock);
75722d39 BH	322	return -EEXIST;
	323	}
	324	}
	325	kref_init(&new_sr->ref);
	326	list_add(&new_sr->link, &wf_sensors);
	327
ac171c46	328	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	329	new_sr->attr.attr.mode = 0444;
	330	new_sr->attr.show = wf_show_sensor;
	331	new_sr->attr.store = NULL;
ccd308f0 SR	332	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	333	printk(KERN_WARNING "windfarm: device_create_file failed"
	334	" for %s\n", new_sr->name);
	335	/* the subsystem still does useful work without the file */
ac171c46	336
75722d39 BH	337	DBG("wf: Registered sensor %s\n", new_sr->name);
	338
	339	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	340	mutex_unlock(&wf_lock);
75722d39 BH	341
	342	return 0;
	343	}
	344	EXPORT_SYMBOL_GPL(wf_register_sensor);
	345
	346	void wf_unregister_sensor(struct wf_sensor *sr)
	347	{
837e9594	348	mutex_lock(&wf_lock);
75722d39	349	list_del(&sr->link);
837e9594	350	mutex_unlock(&wf_lock);
75722d39 BH	351
	352	DBG("wf: Unregistered sensor %s\n", sr->name);
	353
	354	wf_put_sensor(sr);
	355	}
	356	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	357
	358	struct wf_sensor * wf_find_sensor(const char *name)
	359	{
	360	struct wf_sensor *sr;
	361
837e9594	362	mutex_lock(&wf_lock);
75722d39 BH	363	list_for_each_entry(sr, &wf_sensors, link) {
	364	if (!strcmp(sr->name, name)) {
	365	if (wf_get_sensor(sr))
	366	sr = NULL;
837e9594	367	mutex_unlock(&wf_lock);
75722d39 BH	368	return sr;
	369	}
	370	}
837e9594	371	mutex_unlock(&wf_lock);
75722d39 BH	372	return NULL;
	373	}
	374	EXPORT_SYMBOL_GPL(wf_find_sensor);
	375
	376	int wf_get_sensor(struct wf_sensor *sr)
	377	{
	378	if (!try_module_get(sr->ops->owner))
	379	return -ENODEV;
	380	kref_get(&sr->ref);
	381	return 0;
	382	}
	383	EXPORT_SYMBOL_GPL(wf_get_sensor);
	384
	385	void wf_put_sensor(struct wf_sensor *sr)
	386	{
	387	struct module *mod = sr->ops->owner;
	388	kref_put(&sr->ref, wf_sensor_release);
	389	module_put(mod);
	390	}
	391	EXPORT_SYMBOL_GPL(wf_put_sensor);
	392
	393
	394	/*
	395	* Client & notification
	396	*/
	397
	398	int wf_register_client(struct notifier_block *nb)
	399	{
	400	int rc;
	401	struct wf_control *ct;
	402	struct wf_sensor *sr;
	403
837e9594	404	mutex_lock(&wf_lock);
e041c683	405	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	406	if (rc != 0)
	407	goto bail;
	408	wf_client_count++;
	409	list_for_each_entry(ct, &wf_controls, link)
	410	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	411	list_for_each_entry(sr, &wf_sensors, link)
	412	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	413	if (wf_client_count == 1)
	414	wf_start_thread();
	415	bail:
837e9594	416	mutex_unlock(&wf_lock);
75722d39 BH	417	return rc;
	418	}
	419	EXPORT_SYMBOL_GPL(wf_register_client);
	420
	421	int wf_unregister_client(struct notifier_block *nb)
	422	{
837e9594	423	mutex_lock(&wf_lock);
e041c683	424	blocking_notifier_chain_unregister(&wf_client_list, nb);
75722d39 BH	425	wf_client_count++;
	426	if (wf_client_count == 0)
	427	wf_stop_thread();
837e9594	428	mutex_unlock(&wf_lock);
75722d39 BH	429
	430	return 0;
	431	}
	432	EXPORT_SYMBOL_GPL(wf_unregister_client);
	433
	434	void wf_set_overtemp(void)
	435	{
837e9594	436	mutex_lock(&wf_lock);
75722d39 BH	437	wf_overtemp++;
	438	if (wf_overtemp == 1) {
	439	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	440	wf_overtemp_counter = 0;
	441	wf_notify(WF_EVENT_OVERTEMP, NULL);
	442	}
837e9594	443	mutex_unlock(&wf_lock);
75722d39 BH	444	}
	445	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	446
	447	void wf_clear_overtemp(void)
	448	{
837e9594	449	mutex_lock(&wf_lock);
75722d39 BH	450	WARN_ON(wf_overtemp == 0);
75722d39 BH	451	if (wf_overtemp == 0) {
837e9594	452	mutex_unlock(&wf_lock);
75722d39 BH	453	return;
	454	}
	455	wf_overtemp--;
	456	if (wf_overtemp == 0) {
	457	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	458	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	459	}
837e9594	460	mutex_unlock(&wf_lock);
75722d39 BH	461	}
	462	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	463
	464	int wf_is_overtemp(void)
	465	{
	466	return (wf_overtemp != 0);
	467	}
	468	EXPORT_SYMBOL_GPL(wf_is_overtemp);
	469
75722d39 BH	470	static int __init windfarm_core_init(void)
	471	{
	472	DBG("wf: core loaded\n");
	473
b55fafc5 BH	474	/* Don't register on old machines that use therm_pm72 for now */
	475	if (machine_is_compatible("PowerMac7,2") \|\|
	476	machine_is_compatible("PowerMac7,3") \|\|
	477	machine_is_compatible("RackMac3,1"))
	478	return -ENODEV;
75722d39 BH	479	platform_device_register(&wf_platform_device);
	480	return 0;
	481	}
	482
	483	static void __exit windfarm_core_exit(void)
	484	{
	485	BUG_ON(wf_client_count != 0);
	486
	487	DBG("wf: core unloaded\n");
	488
	489	platform_device_unregister(&wf_platform_device);
	490	}
	491
	492
	493	module_init(windfarm_core_init);
	494	module_exit(windfarm_core_exit);
	495
	496	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	497	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	498	MODULE_LICENSE("GPL");
	499