[linux-2.6-block.git] / drivers / macintosh / windfarm_core.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Windfarm PowerMac thermal control. Core
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <benh@kernel.crashing.org>
 *
 * 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 "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;
static 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
2c162f9b	1	// SPDX-License-Identifier: GPL-2.0-only
75722d39 BH	2	/*
	3	* Windfarm PowerMac thermal control. Core
	4	*
	5	* (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
	6	* <benh@kernel.crashing.org>
	7	*
75722d39 BH	8	* This core code tracks the list of sensors & controls, register
	9	* clients, and holds the kernel thread used for control.
	10	*
	11	* TODO:
	12	*
	13	* Add some information about sensor/control type and data format to
	14	* sensors/controls, and have the sysfs attribute stuff be moved
	15	* generically here instead of hard coded in the platform specific
	16	* driver as it us currently
	17	*
	18	* This however requires solving some annoying lifetime issues with
	19	* sysfs which doesn't seem to have lifetime rules for struct attribute,
	20	* I may have to create full features kobjects for every sensor/control
	21	* instead which is a bit of an overkill imho
	22	*/
	23
	24	#include <linux/types.h>
	25	#include <linux/errno.h>
	26	#include <linux/kernel.h>
5a0e3ad6	27	#include <linux/slab.h>
75722d39 BH	28	#include <linux/init.h>
75722d39 BH	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 BH	37
	38	#include "windfarm.h"
	39
	40	#define VERSION "0.2"
	41
	42	#undef DEBUG
	43
	44	#ifdef DEBUG
	45	#define DBG(args...) printk(args)
	46	#else
	47	#define DBG(args...) do { } while(0)
	48	#endif
	49
	50	static LIST_HEAD(wf_controls);
	51	static LIST_HEAD(wf_sensors);
837e9594	52	static DEFINE_MUTEX(wf_lock);
e041c683	53	static BLOCKING_NOTIFIER_HEAD(wf_client_list);
75722d39 BH	54	static int wf_client_count;
	55	static unsigned int wf_overtemp;
	56	static unsigned int wf_overtemp_counter;
4204ecd5	57	static struct task_struct *wf_thread;
75722d39	58
ac171c46 BH	59	static struct platform_device wf_platform_device = {
	60	.name = "windfarm",
	61	};
	62
75722d39 BH	63	/*
	64	* Utilities & tick thread
	65	*/
	66
	67	static inline void wf_notify(int event, void *param)
	68	{
e041c683	69	blocking_notifier_call_chain(&wf_client_list, event, param);
75722d39 BH	70	}
75722d39 BH	71
ca94bbab	72	static int wf_critical_overtemp(void)
75722d39	73	{
377e7a27 GKH	74	static char const critical_overtemp_path[] = "/sbin/critical_overtemp";
377e7a27 GKH	75	char argv[] = { (char )critical_overtemp_path, NULL };
75722d39 BH	76	static char *envp[] = { "HOME=/",
	77	"TERM=linux",
	78	"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
	79	NULL };
	80
86313c48 JF	81	return call_usermodehelper(critical_overtemp_path,
86313c48 JF	82	argv, envp, UMH_WAIT_EXEC);
75722d39	83	}
75722d39 BH	84
	85	static int wf_thread_func(void *data)
	86	{
	87	unsigned long next, delay;
	88
	89	next = jiffies;
	90
	91	DBG("wf: thread started\n");
	92
83144186	93	set_freezable();
67b60518 JB	94	while (!kthread_should_stop()) {
	95	try_to_freeze();
	96
75722d39 BH	97	if (time_after_eq(jiffies, next)) {
	98	wf_notify(WF_EVENT_TICK, NULL);
	99	if (wf_overtemp) {
	100	wf_overtemp_counter++;
	101	/* 10 seconds overtemp, notify userland */
	102	if (wf_overtemp_counter > 10)
	103	wf_critical_overtemp();
	104	/* 30 seconds, shutdown */
	105	if (wf_overtemp_counter > 30) {
	106	printk(KERN_ERR "windfarm: Overtemp "
	107	"for more than 30"
	108	" seconds, shutting down\n");
	109	machine_power_off();
	110	}
	111	}
	112	next += HZ;
	113	}
	114
	115	delay = next - jiffies;
	116	if (delay <= HZ)
	117	schedule_timeout_interruptible(delay);
75722d39 BH	118	}
	119
	120	DBG("wf: thread stopped\n");
	121
	122	return 0;
	123	}
	124
	125	static void wf_start_thread(void)
	126	{
	127	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	128	if (IS_ERR(wf_thread)) {
	129	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
	130	PTR_ERR(wf_thread));
	131	wf_thread = NULL;
	132	}
	133	}
	134
	135
	136	static void wf_stop_thread(void)
	137	{
	138	if (wf_thread)
	139	kthread_stop(wf_thread);
	140	wf_thread = NULL;
	141	}
	142
	143	/*
	144	* Controls
	145	*/
	146
	147	static void wf_control_release(struct kref *kref)
	148	{
	149	struct wf_control *ct = container_of(kref, struct wf_control, ref);
	150
	151	DBG("wf: Deleting control %s\n", ct->name);
	152
	153	if (ct->ops && ct->ops->release)
	154	ct->ops->release(ct);
	155	else
	156	kfree(ct);
	157	}
	158
ac171c46 BH	159	static ssize_t wf_show_control(struct device *dev,
	160	struct device_attribute attr, char buf)
	161	{
	162	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
ea5c64b0	163	const char *typestr;
ac171c46 BH	164	s32 val = 0;
	165	int err;
	166
	167	err = ctrl->ops->get_value(ctrl, &val);
6cd32099 BH	168	if (err < 0) {
	169	if (err == -EFAULT)
	170	return sprintf(buf, "<HW FAULT>\n");
ac171c46	171	return err;
6cd32099	172	}
ea5c64b0 BH	173	switch(ctrl->type) {
	174	case WF_CONTROL_RPM_FAN:
	175	typestr = " RPM";
	176	break;
	177	case WF_CONTROL_PWM_FAN:
	178	typestr = " %";
	179	break;
	180	default:
	181	typestr = "";
	182	}
	183	return sprintf(buf, "%d%s\n", val, typestr);
ac171c46 BH	184	}
	185
	186	/* This is really only for debugging... */
	187	static ssize_t wf_store_control(struct device *dev,
	188	struct device_attribute *attr,
	189	const char *buf, size_t count)
	190	{
	191	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	192	int val;
	193	int err;
	194	char *endp;
	195
	196	val = simple_strtoul(buf, &endp, 0);
	197	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	198	++endp;
	199	if (endp - buf < count)
	200	return -EINVAL;
	201	err = ctrl->ops->set_value(ctrl, val);
	202	if (err < 0)
	203	return err;
	204	return count;
	205	}
	206
75722d39 BH	207	int wf_register_control(struct wf_control *new_ct)
	208	{
	209	struct wf_control *ct;
	210
837e9594	211	mutex_lock(&wf_lock);
75722d39 BH	212	list_for_each_entry(ct, &wf_controls, link) {
	213	if (!strcmp(ct->name, new_ct->name)) {
	214	printk(KERN_WARNING "windfarm: trying to register"
	215	" duplicate control %s\n", ct->name);
837e9594	216	mutex_unlock(&wf_lock);
75722d39 BH	217	return -EEXIST;
	218	}
	219	}
	220	kref_init(&new_ct->ref);
	221	list_add(&new_ct->link, &wf_controls);
	222
12765517	223	sysfs_attr_init(&new_ct->attr.attr);
ac171c46	224	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	225	new_ct->attr.attr.mode = 0644;
	226	new_ct->attr.show = wf_show_control;
	227	new_ct->attr.store = wf_store_control;
ccd308f0 SR	228	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	229	printk(KERN_WARNING "windfarm: device_create_file failed"
	230	" for %s\n", new_ct->name);
	231	/* the subsystem still does useful work without the file */
ac171c46	232
75722d39 BH	233	DBG("wf: Registered control %s\n", new_ct->name);
	234
	235	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	236	mutex_unlock(&wf_lock);
75722d39 BH	237
	238	return 0;
	239	}
	240	EXPORT_SYMBOL_GPL(wf_register_control);
	241
	242	void wf_unregister_control(struct wf_control *ct)
	243	{
837e9594	244	mutex_lock(&wf_lock);
75722d39	245	list_del(&ct->link);
837e9594	246	mutex_unlock(&wf_lock);
75722d39 BH	247
	248	DBG("wf: Unregistered control %s\n", ct->name);
	249
	250	kref_put(&ct->ref, wf_control_release);
	251	}
	252	EXPORT_SYMBOL_GPL(wf_unregister_control);
	253
75722d39 BH	254	int wf_get_control(struct wf_control *ct)
	255	{
	256	if (!try_module_get(ct->ops->owner))
	257	return -ENODEV;
	258	kref_get(&ct->ref);
	259	return 0;
	260	}
	261	EXPORT_SYMBOL_GPL(wf_get_control);
	262
	263	void wf_put_control(struct wf_control *ct)
	264	{
	265	struct module *mod = ct->ops->owner;
	266	kref_put(&ct->ref, wf_control_release);
	267	module_put(mod);
	268	}
	269	EXPORT_SYMBOL_GPL(wf_put_control);
	270
	271
	272	/*
	273	* Sensors
	274	*/
	275
	276
	277	static void wf_sensor_release(struct kref *kref)
	278	{
	279	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	280
	281	DBG("wf: Deleting sensor %s\n", sr->name);
	282
	283	if (sr->ops && sr->ops->release)
	284	sr->ops->release(sr);
	285	else
	286	kfree(sr);
	287	}
	288
ac171c46 BH	289	static ssize_t wf_show_sensor(struct device *dev,
	290	struct device_attribute attr, char buf)
	291	{
	292	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	293	s32 val = 0;
	294	int err;
	295
	296	err = sens->ops->get_value(sens, &val);
	297	if (err < 0)
	298	return err;
	299	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	300	}
	301
75722d39 BH	302	int wf_register_sensor(struct wf_sensor *new_sr)
	303	{
	304	struct wf_sensor *sr;
	305
837e9594	306	mutex_lock(&wf_lock);
75722d39 BH	307	list_for_each_entry(sr, &wf_sensors, link) {
	308	if (!strcmp(sr->name, new_sr->name)) {
	309	printk(KERN_WARNING "windfarm: trying to register"
	310	" duplicate sensor %s\n", sr->name);
837e9594	311	mutex_unlock(&wf_lock);
75722d39 BH	312	return -EEXIST;
	313	}
	314	}
	315	kref_init(&new_sr->ref);
	316	list_add(&new_sr->link, &wf_sensors);
	317
b35c74da	318	sysfs_attr_init(&new_sr->attr.attr);
ac171c46	319	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	320	new_sr->attr.attr.mode = 0444;
	321	new_sr->attr.show = wf_show_sensor;
	322	new_sr->attr.store = NULL;
ccd308f0 SR	323	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	324	printk(KERN_WARNING "windfarm: device_create_file failed"
	325	" for %s\n", new_sr->name);
	326	/* the subsystem still does useful work without the file */
ac171c46	327
75722d39 BH	328	DBG("wf: Registered sensor %s\n", new_sr->name);
	329
	330	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	331	mutex_unlock(&wf_lock);
75722d39 BH	332
	333	return 0;
	334	}
	335	EXPORT_SYMBOL_GPL(wf_register_sensor);
	336
	337	void wf_unregister_sensor(struct wf_sensor *sr)
	338	{
837e9594	339	mutex_lock(&wf_lock);
75722d39	340	list_del(&sr->link);
837e9594	341	mutex_unlock(&wf_lock);
75722d39 BH	342
	343	DBG("wf: Unregistered sensor %s\n", sr->name);
	344
	345	wf_put_sensor(sr);
	346	}
	347	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	348
75722d39 BH	349	int wf_get_sensor(struct wf_sensor *sr)
	350	{
	351	if (!try_module_get(sr->ops->owner))
	352	return -ENODEV;
	353	kref_get(&sr->ref);
	354	return 0;
	355	}
	356	EXPORT_SYMBOL_GPL(wf_get_sensor);
	357
	358	void wf_put_sensor(struct wf_sensor *sr)
	359	{
	360	struct module *mod = sr->ops->owner;
	361	kref_put(&sr->ref, wf_sensor_release);
	362	module_put(mod);
	363	}
	364	EXPORT_SYMBOL_GPL(wf_put_sensor);
	365
	366
	367	/*
	368	* Client & notification
	369	*/
	370
	371	int wf_register_client(struct notifier_block *nb)
	372	{
	373	int rc;
	374	struct wf_control *ct;
	375	struct wf_sensor *sr;
	376
837e9594	377	mutex_lock(&wf_lock);
e041c683	378	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	379	if (rc != 0)
	380	goto bail;
	381	wf_client_count++;
	382	list_for_each_entry(ct, &wf_controls, link)
	383	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	384	list_for_each_entry(sr, &wf_sensors, link)
	385	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	386	if (wf_client_count == 1)
	387	wf_start_thread();
	388	bail:
837e9594	389	mutex_unlock(&wf_lock);
75722d39 BH	390	return rc;
	391	}
	392	EXPORT_SYMBOL_GPL(wf_register_client);
	393
	394	int wf_unregister_client(struct notifier_block *nb)
	395	{
837e9594	396	mutex_lock(&wf_lock);
e041c683	397	blocking_notifier_chain_unregister(&wf_client_list, nb);
fe2b5921	398	wf_client_count--;
75722d39 BH	399	if (wf_client_count == 0)
75722d39 BH	400	wf_stop_thread();
837e9594	401	mutex_unlock(&wf_lock);
75722d39 BH	402
	403	return 0;
	404	}
	405	EXPORT_SYMBOL_GPL(wf_unregister_client);
	406
	407	void wf_set_overtemp(void)
	408	{
837e9594	409	mutex_lock(&wf_lock);
75722d39 BH	410	wf_overtemp++;
	411	if (wf_overtemp == 1) {
	412	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	413	wf_overtemp_counter = 0;
	414	wf_notify(WF_EVENT_OVERTEMP, NULL);
	415	}
837e9594	416	mutex_unlock(&wf_lock);
75722d39 BH	417	}
	418	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	419
	420	void wf_clear_overtemp(void)
	421	{
837e9594	422	mutex_lock(&wf_lock);
75722d39 BH	423	WARN_ON(wf_overtemp == 0);
75722d39 BH	424	if (wf_overtemp == 0) {
837e9594	425	mutex_unlock(&wf_lock);
75722d39 BH	426	return;
	427	}
	428	wf_overtemp--;
	429	if (wf_overtemp == 0) {
	430	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	431	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	432	}
837e9594	433	mutex_unlock(&wf_lock);
75722d39 BH	434	}
	435	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	436
75722d39 BH	437	static int __init windfarm_core_init(void)
	438	{
	439	DBG("wf: core loaded\n");
	440
	441	platform_device_register(&wf_platform_device);
	442	return 0;
	443	}
	444
	445	static void __exit windfarm_core_exit(void)
	446	{
	447	BUG_ON(wf_client_count != 0);
	448
	449	DBG("wf: core unloaded\n");
	450
	451	platform_device_unregister(&wf_platform_device);
	452	}
	453
	454
	455	module_init(windfarm_core_init);
	456	module_exit(windfarm_core_exit);
	457
	458	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	459	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	460	MODULE_LICENSE("GPL");
	461