[mirror_ubuntu-jammy-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/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, 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()) {
		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
	83	return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
	84	}
	85	EXPORT_SYMBOL_GPL(wf_critical_overtemp);
	86
	87	static int wf_thread_func(void *data)
	88	{
	89	unsigned long next, delay;
	90
	91	next = jiffies;
	92
	93	DBG("wf: thread started\n");
	94
	95	while(!kthread_should_stop()) {
75722d39 BH	96	if (time_after_eq(jiffies, next)) {
	97	wf_notify(WF_EVENT_TICK, NULL);
	98	if (wf_overtemp) {
	99	wf_overtemp_counter++;
	100	/* 10 seconds overtemp, notify userland */
	101	if (wf_overtemp_counter > 10)
	102	wf_critical_overtemp();
	103	/* 30 seconds, shutdown */
	104	if (wf_overtemp_counter > 30) {
	105	printk(KERN_ERR "windfarm: Overtemp "
	106	"for more than 30"
	107	" seconds, shutting down\n");
	108	machine_power_off();
	109	}
	110	}
	111	next += HZ;
	112	}
	113
	114	delay = next - jiffies;
	115	if (delay <= HZ)
	116	schedule_timeout_interruptible(delay);
	117
1ed2ddf3 JB	118	/* there should be no non-suspend signal, but oh well */
1ed2ddf3 JB	119	if (signal_pending(current) && !try_to_freeze()) {
75722d39 BH	120	printk(KERN_WARNING "windfarm: thread got sigl !\n");
	121	break;
	122	}
	123	}
	124
	125	DBG("wf: thread stopped\n");
	126
	127	return 0;
	128	}
	129
	130	static void wf_start_thread(void)
	131	{
	132	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	133	if (IS_ERR(wf_thread)) {
	134	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
	135	PTR_ERR(wf_thread));
	136	wf_thread = NULL;
	137	}
	138	}
	139
	140
	141	static void wf_stop_thread(void)
	142	{
	143	if (wf_thread)
	144	kthread_stop(wf_thread);
	145	wf_thread = NULL;
	146	}
	147
	148	/*
	149	* Controls
	150	*/
	151
	152	static void wf_control_release(struct kref *kref)
	153	{
	154	struct wf_control *ct = container_of(kref, struct wf_control, ref);
	155
	156	DBG("wf: Deleting control %s\n", ct->name);
	157
	158	if (ct->ops && ct->ops->release)
	159	ct->ops->release(ct);
	160	else
	161	kfree(ct);
	162	}
	163
ac171c46 BH	164	static ssize_t wf_show_control(struct device *dev,
	165	struct device_attribute attr, char buf)
	166	{
	167	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	168	s32 val = 0;
	169	int err;
	170
	171	err = ctrl->ops->get_value(ctrl, &val);
	172	if (err < 0)
	173	return err;
	174	return sprintf(buf, "%d\n", val);
	175	}
	176
	177	/* This is really only for debugging... */
	178	static ssize_t wf_store_control(struct device *dev,
	179	struct device_attribute *attr,
	180	const char *buf, size_t count)
	181	{
	182	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	183	int val;
	184	int err;
	185	char *endp;
	186
	187	val = simple_strtoul(buf, &endp, 0);
	188	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	189	++endp;
	190	if (endp - buf < count)
	191	return -EINVAL;
	192	err = ctrl->ops->set_value(ctrl, val);
	193	if (err < 0)
	194	return err;
	195	return count;
	196	}
	197
75722d39 BH	198	int wf_register_control(struct wf_control *new_ct)
	199	{
	200	struct wf_control *ct;
	201
837e9594	202	mutex_lock(&wf_lock);
75722d39 BH	203	list_for_each_entry(ct, &wf_controls, link) {
	204	if (!strcmp(ct->name, new_ct->name)) {
	205	printk(KERN_WARNING "windfarm: trying to register"
	206	" duplicate control %s\n", ct->name);
837e9594	207	mutex_unlock(&wf_lock);
75722d39 BH	208	return -EEXIST;
	209	}
	210	}
	211	kref_init(&new_ct->ref);
	212	list_add(&new_ct->link, &wf_controls);
	213
ac171c46	214	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	215	new_ct->attr.attr.mode = 0644;
	216	new_ct->attr.show = wf_show_control;
	217	new_ct->attr.store = wf_store_control;
ccd308f0 SR	218	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	219	printk(KERN_WARNING "windfarm: device_create_file failed"
	220	" for %s\n", new_ct->name);
	221	/* the subsystem still does useful work without the file */
ac171c46	222
75722d39 BH	223	DBG("wf: Registered control %s\n", new_ct->name);
	224
	225	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	226	mutex_unlock(&wf_lock);
75722d39 BH	227
	228	return 0;
	229	}
	230	EXPORT_SYMBOL_GPL(wf_register_control);
	231
	232	void wf_unregister_control(struct wf_control *ct)
	233	{
837e9594	234	mutex_lock(&wf_lock);
75722d39	235	list_del(&ct->link);
837e9594	236	mutex_unlock(&wf_lock);
75722d39 BH	237
	238	DBG("wf: Unregistered control %s\n", ct->name);
	239
	240	kref_put(&ct->ref, wf_control_release);
	241	}
	242	EXPORT_SYMBOL_GPL(wf_unregister_control);
	243
	244	struct wf_control * wf_find_control(const char *name)
	245	{
	246	struct wf_control *ct;
	247
837e9594	248	mutex_lock(&wf_lock);
75722d39 BH	249	list_for_each_entry(ct, &wf_controls, link) {
	250	if (!strcmp(ct->name, name)) {
	251	if (wf_get_control(ct))
	252	ct = NULL;
837e9594	253	mutex_unlock(&wf_lock);
75722d39 BH	254	return ct;
	255	}
	256	}
837e9594	257	mutex_unlock(&wf_lock);
75722d39 BH	258	return NULL;
	259	}
	260	EXPORT_SYMBOL_GPL(wf_find_control);
	261
	262	int wf_get_control(struct wf_control *ct)
	263	{
	264	if (!try_module_get(ct->ops->owner))
	265	return -ENODEV;
	266	kref_get(&ct->ref);
	267	return 0;
	268	}
	269	EXPORT_SYMBOL_GPL(wf_get_control);
	270
	271	void wf_put_control(struct wf_control *ct)
	272	{
	273	struct module *mod = ct->ops->owner;
	274	kref_put(&ct->ref, wf_control_release);
	275	module_put(mod);
	276	}
	277	EXPORT_SYMBOL_GPL(wf_put_control);
	278
	279
	280	/*
	281	* Sensors
	282	*/
	283
	284
	285	static void wf_sensor_release(struct kref *kref)
	286	{
	287	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	288
	289	DBG("wf: Deleting sensor %s\n", sr->name);
	290
	291	if (sr->ops && sr->ops->release)
	292	sr->ops->release(sr);
	293	else
	294	kfree(sr);
	295	}
	296
ac171c46 BH	297	static ssize_t wf_show_sensor(struct device *dev,
	298	struct device_attribute attr, char buf)
	299	{
	300	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	301	s32 val = 0;
	302	int err;
	303
	304	err = sens->ops->get_value(sens, &val);
	305	if (err < 0)
	306	return err;
	307	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	308	}
	309
75722d39 BH	310	int wf_register_sensor(struct wf_sensor *new_sr)
	311	{
	312	struct wf_sensor *sr;
	313
837e9594	314	mutex_lock(&wf_lock);
75722d39 BH	315	list_for_each_entry(sr, &wf_sensors, link) {
	316	if (!strcmp(sr->name, new_sr->name)) {
	317	printk(KERN_WARNING "windfarm: trying to register"
	318	" duplicate sensor %s\n", sr->name);
837e9594	319	mutex_unlock(&wf_lock);
75722d39 BH	320	return -EEXIST;
	321	}
	322	}
	323	kref_init(&new_sr->ref);
	324	list_add(&new_sr->link, &wf_sensors);
	325
ac171c46	326	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	327	new_sr->attr.attr.mode = 0444;
	328	new_sr->attr.show = wf_show_sensor;
	329	new_sr->attr.store = NULL;
ccd308f0 SR	330	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	331	printk(KERN_WARNING "windfarm: device_create_file failed"
	332	" for %s\n", new_sr->name);
	333	/* the subsystem still does useful work without the file */
ac171c46	334
75722d39 BH	335	DBG("wf: Registered sensor %s\n", new_sr->name);
	336
	337	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	338	mutex_unlock(&wf_lock);
75722d39 BH	339
	340	return 0;
	341	}
	342	EXPORT_SYMBOL_GPL(wf_register_sensor);
	343
	344	void wf_unregister_sensor(struct wf_sensor *sr)
	345	{
837e9594	346	mutex_lock(&wf_lock);
75722d39	347	list_del(&sr->link);
837e9594	348	mutex_unlock(&wf_lock);
75722d39 BH	349
	350	DBG("wf: Unregistered sensor %s\n", sr->name);
	351
	352	wf_put_sensor(sr);
	353	}
	354	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	355
	356	struct wf_sensor * wf_find_sensor(const char *name)
	357	{
	358	struct wf_sensor *sr;
	359
837e9594	360	mutex_lock(&wf_lock);
75722d39 BH	361	list_for_each_entry(sr, &wf_sensors, link) {
	362	if (!strcmp(sr->name, name)) {
	363	if (wf_get_sensor(sr))
	364	sr = NULL;
837e9594	365	mutex_unlock(&wf_lock);
75722d39 BH	366	return sr;
	367	}
	368	}
837e9594	369	mutex_unlock(&wf_lock);
75722d39 BH	370	return NULL;
	371	}
	372	EXPORT_SYMBOL_GPL(wf_find_sensor);
	373
	374	int wf_get_sensor(struct wf_sensor *sr)
	375	{
	376	if (!try_module_get(sr->ops->owner))
	377	return -ENODEV;
	378	kref_get(&sr->ref);
	379	return 0;
	380	}
	381	EXPORT_SYMBOL_GPL(wf_get_sensor);
	382
	383	void wf_put_sensor(struct wf_sensor *sr)
	384	{
	385	struct module *mod = sr->ops->owner;
	386	kref_put(&sr->ref, wf_sensor_release);
	387	module_put(mod);
	388	}
	389	EXPORT_SYMBOL_GPL(wf_put_sensor);
	390
	391
	392	/*
	393	* Client & notification
	394	*/
	395
	396	int wf_register_client(struct notifier_block *nb)
	397	{
	398	int rc;
	399	struct wf_control *ct;
	400	struct wf_sensor *sr;
	401
837e9594	402	mutex_lock(&wf_lock);
e041c683	403	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	404	if (rc != 0)
	405	goto bail;
	406	wf_client_count++;
	407	list_for_each_entry(ct, &wf_controls, link)
	408	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	409	list_for_each_entry(sr, &wf_sensors, link)
	410	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	411	if (wf_client_count == 1)
	412	wf_start_thread();
	413	bail:
837e9594	414	mutex_unlock(&wf_lock);
75722d39 BH	415	return rc;
	416	}
	417	EXPORT_SYMBOL_GPL(wf_register_client);
	418
	419	int wf_unregister_client(struct notifier_block *nb)
	420	{
837e9594	421	mutex_lock(&wf_lock);
e041c683	422	blocking_notifier_chain_unregister(&wf_client_list, nb);
75722d39 BH	423	wf_client_count++;
	424	if (wf_client_count == 0)
	425	wf_stop_thread();
837e9594	426	mutex_unlock(&wf_lock);
75722d39 BH	427
	428	return 0;
	429	}
	430	EXPORT_SYMBOL_GPL(wf_unregister_client);
	431
	432	void wf_set_overtemp(void)
	433	{
837e9594	434	mutex_lock(&wf_lock);
75722d39 BH	435	wf_overtemp++;
	436	if (wf_overtemp == 1) {
	437	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	438	wf_overtemp_counter = 0;
	439	wf_notify(WF_EVENT_OVERTEMP, NULL);
	440	}
837e9594	441	mutex_unlock(&wf_lock);
75722d39 BH	442	}
	443	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	444
	445	void wf_clear_overtemp(void)
	446	{
837e9594	447	mutex_lock(&wf_lock);
75722d39 BH	448	WARN_ON(wf_overtemp == 0);
75722d39 BH	449	if (wf_overtemp == 0) {
837e9594	450	mutex_unlock(&wf_lock);
75722d39 BH	451	return;
	452	}
	453	wf_overtemp--;
	454	if (wf_overtemp == 0) {
	455	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	456	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	457	}
837e9594	458	mutex_unlock(&wf_lock);
75722d39 BH	459	}
	460	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	461
	462	int wf_is_overtemp(void)
	463	{
	464	return (wf_overtemp != 0);
	465	}
	466	EXPORT_SYMBOL_GPL(wf_is_overtemp);
	467
75722d39 BH	468	static int __init windfarm_core_init(void)
	469	{
	470	DBG("wf: core loaded\n");
	471
b55fafc5 BH	472	/* Don't register on old machines that use therm_pm72 for now */
	473	if (machine_is_compatible("PowerMac7,2") \|\|
	474	machine_is_compatible("PowerMac7,3") \|\|
	475	machine_is_compatible("RackMac3,1"))
	476	return -ENODEV;
75722d39 BH	477	platform_device_register(&wf_platform_device);
	478	return 0;
	479	}
	480
	481	static void __exit windfarm_core_exit(void)
	482	{
	483	BUG_ON(wf_client_count != 0);
	484
	485	DBG("wf: core unloaded\n");
	486
	487	platform_device_unregister(&wf_platform_device);
	488	}
	489
	490
	491	module_init(windfarm_core_init);
	492	module_exit(windfarm_core_exit);
	493
	494	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	495	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	496	MODULE_LICENSE("GPL");
	497