[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/slab.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/kthread.h>
#include <linux/jiffies.h>
#include <linux/reboot.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/freezer.h>

#include <asm/prom.h>

#include "windfarm.h"

#define VERSION "0.2"

#undef DEBUG

#ifdef DEBUG
#define DBG(args...)	printk(args)
#else
#define DBG(args...)	do { } while(0)
#endif

static LIST_HEAD(wf_controls);
static LIST_HEAD(wf_sensors);
static DEFINE_MUTEX(wf_lock);
static BLOCKING_NOTIFIER_HEAD(wf_client_list);
static int wf_client_count;
static unsigned int wf_overtemp;
static unsigned int wf_overtemp_counter;
struct task_struct *wf_thread;

static struct platform_device wf_platform_device = {
	.name	= "windfarm",
};

/*
 * Utilities & tick thread
 */

static inline void wf_notify(int event, void *param)
{
	blocking_notifier_call_chain(&wf_client_list, event, param);
}

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);
	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);

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");

	platform_device_register(&wf_platform_device);
	return 0;
}

static void __exit windfarm_core_exit(void)
{
	BUG_ON(wf_client_count != 0);

	DBG("wf: core unloaded\n");

	platform_device_unregister(&wf_platform_device);
}


module_init(windfarm_core_init);
module_exit(windfarm_core_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("Core component of PowerMac thermal control");
MODULE_LICENSE("GPL");
Commit	Line	Data
75722d39 BH	1	/*
	2	* Windfarm PowerMac thermal control. Core
	3	*
	4	* (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
	5	* <benh@kernel.crashing.org>
	6	*
	7	* Released under the term of the GNU GPL v2.
	8	*
	9	* This core code tracks the list of sensors & controls, register
	10	* clients, and holds the kernel thread used for control.
	11	*
	12	* TODO:
	13	*
	14	* Add some information about sensor/control type and data format to
	15	* sensors/controls, and have the sysfs attribute stuff be moved
	16	* generically here instead of hard coded in the platform specific
	17	* driver as it us currently
	18	*
	19	* This however requires solving some annoying lifetime issues with
	20	* sysfs which doesn't seem to have lifetime rules for struct attribute,
	21	* I may have to create full features kobjects for every sensor/control
	22	* instead which is a bit of an overkill imho
	23	*/
	24
	25	#include <linux/types.h>
	26	#include <linux/errno.h>
	27	#include <linux/kernel.h>
5a0e3ad6	28	#include <linux/slab.h>
75722d39 BH	29	#include <linux/init.h>
75722d39 BH	30	#include <linux/spinlock.h>
75722d39 BH	31	#include <linux/kthread.h>
	32	#include <linux/jiffies.h>
	33	#include <linux/reboot.h>
	34	#include <linux/device.h>
	35	#include <linux/platform_device.h>
837e9594	36	#include <linux/mutex.h>
7dfb7103	37	#include <linux/freezer.h>
75722d39	38
b55fafc5 BH	39	#include <asm/prom.h>
b55fafc5 BH	40
75722d39 BH	41	#include "windfarm.h"
	42
	43	#define VERSION "0.2"
	44
	45	#undef DEBUG
	46
	47	#ifdef DEBUG
	48	#define DBG(args...) printk(args)
	49	#else
	50	#define DBG(args...) do { } while(0)
	51	#endif
	52
	53	static LIST_HEAD(wf_controls);
	54	static LIST_HEAD(wf_sensors);
837e9594	55	static DEFINE_MUTEX(wf_lock);
e041c683	56	static BLOCKING_NOTIFIER_HEAD(wf_client_list);
75722d39 BH	57	static int wf_client_count;
	58	static unsigned int wf_overtemp;
	59	static unsigned int wf_overtemp_counter;
	60	struct task_struct *wf_thread;
	61
ac171c46 BH	62	static struct platform_device wf_platform_device = {
	63	.name = "windfarm",
	64	};
	65
75722d39 BH	66	/*
	67	* Utilities & tick thread
	68	*/
	69
	70	static inline void wf_notify(int event, void *param)
	71	{
e041c683	72	blocking_notifier_call_chain(&wf_client_list, event, param);
75722d39 BH	73	}
	74
	75	int wf_critical_overtemp(void)
	76	{
	77	static char * critical_overtemp_path = "/sbin/critical_overtemp";
	78	char *argv[] = { critical_overtemp_path, NULL };
	79	static char *envp[] = { "HOME=/",
	80	"TERM=linux",
	81	"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
	82	NULL };
	83
86313c48 JF	84	return call_usermodehelper(critical_overtemp_path,
86313c48 JF	85	argv, envp, UMH_WAIT_EXEC);
75722d39 BH	86	}
	87	EXPORT_SYMBOL_GPL(wf_critical_overtemp);
	88
	89	static int wf_thread_func(void *data)
	90	{
	91	unsigned long next, delay;
	92
	93	next = jiffies;
	94
	95	DBG("wf: thread started\n");
	96
83144186	97	set_freezable();
67b60518 JB	98	while (!kthread_should_stop()) {
	99	try_to_freeze();
	100
75722d39 BH	101	if (time_after_eq(jiffies, next)) {
	102	wf_notify(WF_EVENT_TICK, NULL);
	103	if (wf_overtemp) {
	104	wf_overtemp_counter++;
	105	/* 10 seconds overtemp, notify userland */
	106	if (wf_overtemp_counter > 10)
	107	wf_critical_overtemp();
	108	/* 30 seconds, shutdown */
	109	if (wf_overtemp_counter > 30) {
	110	printk(KERN_ERR "windfarm: Overtemp "
	111	"for more than 30"
	112	" seconds, shutting down\n");
	113	machine_power_off();
	114	}
	115	}
	116	next += HZ;
	117	}
	118
	119	delay = next - jiffies;
	120	if (delay <= HZ)
	121	schedule_timeout_interruptible(delay);
75722d39 BH	122	}
	123
	124	DBG("wf: thread stopped\n");
	125
	126	return 0;
	127	}
	128
	129	static void wf_start_thread(void)
	130	{
	131	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	132	if (IS_ERR(wf_thread)) {
	133	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
	134	PTR_ERR(wf_thread));
	135	wf_thread = NULL;
	136	}
	137	}
	138
	139
	140	static void wf_stop_thread(void)
	141	{
	142	if (wf_thread)
	143	kthread_stop(wf_thread);
	144	wf_thread = NULL;
	145	}
	146
	147	/*
	148	* Controls
	149	*/
	150
	151	static void wf_control_release(struct kref *kref)
	152	{
	153	struct wf_control *ct = container_of(kref, struct wf_control, ref);
	154
	155	DBG("wf: Deleting control %s\n", ct->name);
	156
	157	if (ct->ops && ct->ops->release)
	158	ct->ops->release(ct);
	159	else
	160	kfree(ct);
	161	}
	162
ac171c46 BH	163	static ssize_t wf_show_control(struct device *dev,
	164	struct device_attribute attr, char buf)
	165	{
	166	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
ea5c64b0	167	const char *typestr;
ac171c46 BH	168	s32 val = 0;
	169	int err;
	170
	171	err = ctrl->ops->get_value(ctrl, &val);
6cd32099 BH	172	if (err < 0) {
	173	if (err == -EFAULT)
	174	return sprintf(buf, "<HW FAULT>\n");
ac171c46	175	return err;
6cd32099	176	}
ea5c64b0 BH	177	switch(ctrl->type) {
	178	case WF_CONTROL_RPM_FAN:
	179	typestr = " RPM";
	180	break;
	181	case WF_CONTROL_PWM_FAN:
	182	typestr = " %";
	183	break;
	184	default:
	185	typestr = "";
	186	}
	187	return sprintf(buf, "%d%s\n", val, typestr);
ac171c46 BH	188	}
	189
	190	/* This is really only for debugging... */
	191	static ssize_t wf_store_control(struct device *dev,
	192	struct device_attribute *attr,
	193	const char *buf, size_t count)
	194	{
	195	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	196	int val;
	197	int err;
	198	char *endp;
	199
	200	val = simple_strtoul(buf, &endp, 0);
	201	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	202	++endp;
	203	if (endp - buf < count)
	204	return -EINVAL;
	205	err = ctrl->ops->set_value(ctrl, val);
	206	if (err < 0)
	207	return err;
	208	return count;
	209	}
	210
75722d39 BH	211	int wf_register_control(struct wf_control *new_ct)
	212	{
	213	struct wf_control *ct;
	214
837e9594	215	mutex_lock(&wf_lock);
75722d39 BH	216	list_for_each_entry(ct, &wf_controls, link) {
	217	if (!strcmp(ct->name, new_ct->name)) {
	218	printk(KERN_WARNING "windfarm: trying to register"
	219	" duplicate control %s\n", ct->name);
837e9594	220	mutex_unlock(&wf_lock);
75722d39 BH	221	return -EEXIST;
	222	}
	223	}
	224	kref_init(&new_ct->ref);
	225	list_add(&new_ct->link, &wf_controls);
	226
12765517	227	sysfs_attr_init(&new_ct->attr.attr);
ac171c46	228	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	229	new_ct->attr.attr.mode = 0644;
	230	new_ct->attr.show = wf_show_control;
	231	new_ct->attr.store = wf_store_control;
ccd308f0 SR	232	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	233	printk(KERN_WARNING "windfarm: device_create_file failed"
	234	" for %s\n", new_ct->name);
	235	/* the subsystem still does useful work without the file */
ac171c46	236
75722d39 BH	237	DBG("wf: Registered control %s\n", new_ct->name);
	238
	239	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	240	mutex_unlock(&wf_lock);
75722d39 BH	241
	242	return 0;
	243	}
	244	EXPORT_SYMBOL_GPL(wf_register_control);
	245
	246	void wf_unregister_control(struct wf_control *ct)
	247	{
837e9594	248	mutex_lock(&wf_lock);
75722d39	249	list_del(&ct->link);
837e9594	250	mutex_unlock(&wf_lock);
75722d39 BH	251
	252	DBG("wf: Unregistered control %s\n", ct->name);
	253
	254	kref_put(&ct->ref, wf_control_release);
	255	}
	256	EXPORT_SYMBOL_GPL(wf_unregister_control);
	257
	258	struct wf_control * wf_find_control(const char *name)
	259	{
	260	struct wf_control *ct;
	261
837e9594	262	mutex_lock(&wf_lock);
75722d39 BH	263	list_for_each_entry(ct, &wf_controls, link) {
	264	if (!strcmp(ct->name, name)) {
	265	if (wf_get_control(ct))
	266	ct = NULL;
837e9594	267	mutex_unlock(&wf_lock);
75722d39 BH	268	return ct;
	269	}
	270	}
837e9594	271	mutex_unlock(&wf_lock);
75722d39 BH	272	return NULL;
	273	}
	274	EXPORT_SYMBOL_GPL(wf_find_control);
	275
	276	int wf_get_control(struct wf_control *ct)
	277	{
	278	if (!try_module_get(ct->ops->owner))
	279	return -ENODEV;
	280	kref_get(&ct->ref);
	281	return 0;
	282	}
	283	EXPORT_SYMBOL_GPL(wf_get_control);
	284
	285	void wf_put_control(struct wf_control *ct)
	286	{
	287	struct module *mod = ct->ops->owner;
	288	kref_put(&ct->ref, wf_control_release);
	289	module_put(mod);
	290	}
	291	EXPORT_SYMBOL_GPL(wf_put_control);
	292
	293
	294	/*
	295	* Sensors
	296	*/
	297
	298
	299	static void wf_sensor_release(struct kref *kref)
	300	{
	301	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	302
	303	DBG("wf: Deleting sensor %s\n", sr->name);
	304
	305	if (sr->ops && sr->ops->release)
	306	sr->ops->release(sr);
	307	else
	308	kfree(sr);
	309	}
	310
ac171c46 BH	311	static ssize_t wf_show_sensor(struct device *dev,
	312	struct device_attribute attr, char buf)
	313	{
	314	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	315	s32 val = 0;
	316	int err;
	317
	318	err = sens->ops->get_value(sens, &val);
	319	if (err < 0)
	320	return err;
	321	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	322	}
	323
75722d39 BH	324	int wf_register_sensor(struct wf_sensor *new_sr)
	325	{
	326	struct wf_sensor *sr;
	327
837e9594	328	mutex_lock(&wf_lock);
75722d39 BH	329	list_for_each_entry(sr, &wf_sensors, link) {
	330	if (!strcmp(sr->name, new_sr->name)) {
	331	printk(KERN_WARNING "windfarm: trying to register"
	332	" duplicate sensor %s\n", sr->name);
837e9594	333	mutex_unlock(&wf_lock);
75722d39 BH	334	return -EEXIST;
	335	}
	336	}
	337	kref_init(&new_sr->ref);
	338	list_add(&new_sr->link, &wf_sensors);
	339
b35c74da	340	sysfs_attr_init(&new_sr->attr.attr);
ac171c46	341	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	342	new_sr->attr.attr.mode = 0444;
	343	new_sr->attr.show = wf_show_sensor;
	344	new_sr->attr.store = NULL;
ccd308f0 SR	345	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	346	printk(KERN_WARNING "windfarm: device_create_file failed"
	347	" for %s\n", new_sr->name);
	348	/* the subsystem still does useful work without the file */
ac171c46	349
75722d39 BH	350	DBG("wf: Registered sensor %s\n", new_sr->name);
	351
	352	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	353	mutex_unlock(&wf_lock);
75722d39 BH	354
	355	return 0;
	356	}
	357	EXPORT_SYMBOL_GPL(wf_register_sensor);
	358
	359	void wf_unregister_sensor(struct wf_sensor *sr)
	360	{
837e9594	361	mutex_lock(&wf_lock);
75722d39	362	list_del(&sr->link);
837e9594	363	mutex_unlock(&wf_lock);
75722d39 BH	364
	365	DBG("wf: Unregistered sensor %s\n", sr->name);
	366
	367	wf_put_sensor(sr);
	368	}
	369	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	370
	371	struct wf_sensor * wf_find_sensor(const char *name)
	372	{
	373	struct wf_sensor *sr;
	374
837e9594	375	mutex_lock(&wf_lock);
75722d39 BH	376	list_for_each_entry(sr, &wf_sensors, link) {
	377	if (!strcmp(sr->name, name)) {
	378	if (wf_get_sensor(sr))
	379	sr = NULL;
837e9594	380	mutex_unlock(&wf_lock);
75722d39 BH	381	return sr;
	382	}
	383	}
837e9594	384	mutex_unlock(&wf_lock);
75722d39 BH	385	return NULL;
	386	}
	387	EXPORT_SYMBOL_GPL(wf_find_sensor);
	388
	389	int wf_get_sensor(struct wf_sensor *sr)
	390	{
	391	if (!try_module_get(sr->ops->owner))
	392	return -ENODEV;
	393	kref_get(&sr->ref);
	394	return 0;
	395	}
	396	EXPORT_SYMBOL_GPL(wf_get_sensor);
	397
	398	void wf_put_sensor(struct wf_sensor *sr)
	399	{
	400	struct module *mod = sr->ops->owner;
	401	kref_put(&sr->ref, wf_sensor_release);
	402	module_put(mod);
	403	}
	404	EXPORT_SYMBOL_GPL(wf_put_sensor);
	405
	406
	407	/*
	408	* Client & notification
	409	*/
	410
	411	int wf_register_client(struct notifier_block *nb)
	412	{
	413	int rc;
	414	struct wf_control *ct;
	415	struct wf_sensor *sr;
	416
837e9594	417	mutex_lock(&wf_lock);
e041c683	418	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	419	if (rc != 0)
	420	goto bail;
	421	wf_client_count++;
	422	list_for_each_entry(ct, &wf_controls, link)
	423	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	424	list_for_each_entry(sr, &wf_sensors, link)
	425	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	426	if (wf_client_count == 1)
	427	wf_start_thread();
	428	bail:
837e9594	429	mutex_unlock(&wf_lock);
75722d39 BH	430	return rc;
	431	}
	432	EXPORT_SYMBOL_GPL(wf_register_client);
	433
	434	int wf_unregister_client(struct notifier_block *nb)
	435	{
837e9594	436	mutex_lock(&wf_lock);
e041c683	437	blocking_notifier_chain_unregister(&wf_client_list, nb);
75722d39 BH	438	wf_client_count++;
	439	if (wf_client_count == 0)
	440	wf_stop_thread();
837e9594	441	mutex_unlock(&wf_lock);
75722d39 BH	442
	443	return 0;
	444	}
	445	EXPORT_SYMBOL_GPL(wf_unregister_client);
	446
	447	void wf_set_overtemp(void)
	448	{
837e9594	449	mutex_lock(&wf_lock);
75722d39 BH	450	wf_overtemp++;
	451	if (wf_overtemp == 1) {
	452	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	453	wf_overtemp_counter = 0;
	454	wf_notify(WF_EVENT_OVERTEMP, NULL);
	455	}
837e9594	456	mutex_unlock(&wf_lock);
75722d39 BH	457	}
	458	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	459
	460	void wf_clear_overtemp(void)
	461	{
837e9594	462	mutex_lock(&wf_lock);
75722d39 BH	463	WARN_ON(wf_overtemp == 0);
75722d39 BH	464	if (wf_overtemp == 0) {
837e9594	465	mutex_unlock(&wf_lock);
75722d39 BH	466	return;
	467	}
	468	wf_overtemp--;
	469	if (wf_overtemp == 0) {
	470	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	471	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	472	}
837e9594	473	mutex_unlock(&wf_lock);
75722d39 BH	474	}
	475	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	476
	477	int wf_is_overtemp(void)
	478	{
	479	return (wf_overtemp != 0);
	480	}
	481	EXPORT_SYMBOL_GPL(wf_is_overtemp);
	482
75722d39 BH	483	static int __init windfarm_core_init(void)
	484	{
	485	DBG("wf: core loaded\n");
	486
	487	platform_device_register(&wf_platform_device);
	488	return 0;
	489	}
	490
	491	static void __exit windfarm_core_exit(void)
	492	{
	493	BUG_ON(wf_client_count != 0);
	494
	495	DBG("wf: core unloaded\n");
	496
	497	platform_device_unregister(&wf_platform_device);
	498	}
	499
	500
	501	module_init(windfarm_core_init);
	502	module_exit(windfarm_core_exit);
	503
	504	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	505	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	506	MODULE_LICENSE("GPL");
	507