[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / macintosh / windfarm_core.c

/*
 * Windfarm PowerMac thermal control. Core
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <benh@kernel.crashing.org>
 *
 * Released under the term of the GNU GPL v2.
 *
 * This core code tracks the list of sensors & controls, register
 * clients, and holds the kernel thread used for control.
 *
 * TODO:
 *
 * Add some information about sensor/control type and data format to
 * sensors/controls, and have the sysfs attribute stuff be moved
 * generically here instead of hard coded in the platform specific
 * driver as it us currently
 *
 * This however requires solving some annoying lifetime issues with
 * sysfs which doesn't seem to have lifetime rules for struct attribute,
 * I may have to create full features kobjects for every sensor/control
 * instead which is a bit of an overkill imho
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/kthread.h>
#include <linux/jiffies.h>
#include <linux/reboot.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/freezer.h>

#include <asm/prom.h>

#include "windfarm.h"

#define VERSION "0.2"

#undef DEBUG

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

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

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

/*
 * Utilities & tick thread
 */

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

int wf_critical_overtemp(void)
{
	static char * critical_overtemp_path = "/sbin/critical_overtemp";
	char *argv[] = { critical_overtemp_path, NULL };
	static char *envp[] = { "HOME=/",
				"TERM=linux",
				"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
				NULL };

	return call_usermodehelper(critical_overtemp_path, argv, envp, 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");

	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
	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
83144186	95	set_freezable();
75722d39	96	while(!kthread_should_stop()) {
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);
	118
1ed2ddf3 JB	119	/* there should be no non-suspend signal, but oh well */
1ed2ddf3 JB	120	if (signal_pending(current) && !try_to_freeze()) {
75722d39 BH	121	printk(KERN_WARNING "windfarm: thread got sigl !\n");
	122	break;
	123	}
	124	}
	125
	126	DBG("wf: thread stopped\n");
	127
	128	return 0;
	129	}
	130
	131	static void wf_start_thread(void)
	132	{
	133	wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
	134	if (IS_ERR(wf_thread)) {
	135	printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
	136	PTR_ERR(wf_thread));
	137	wf_thread = NULL;
	138	}
	139	}
	140
	141
	142	static void wf_stop_thread(void)
	143	{
	144	if (wf_thread)
	145	kthread_stop(wf_thread);
	146	wf_thread = NULL;
	147	}
	148
	149	/*
	150	* Controls
	151	*/
	152
	153	static void wf_control_release(struct kref *kref)
	154	{
	155	struct wf_control *ct = container_of(kref, struct wf_control, ref);
	156
	157	DBG("wf: Deleting control %s\n", ct->name);
	158
	159	if (ct->ops && ct->ops->release)
	160	ct->ops->release(ct);
	161	else
	162	kfree(ct);
	163	}
	164
ac171c46 BH	165	static ssize_t wf_show_control(struct device *dev,
	166	struct device_attribute attr, char buf)
	167	{
	168	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	169	s32 val = 0;
	170	int err;
	171
	172	err = ctrl->ops->get_value(ctrl, &val);
	173	if (err < 0)
	174	return err;
	175	return sprintf(buf, "%d\n", val);
	176	}
	177
	178	/* This is really only for debugging... */
	179	static ssize_t wf_store_control(struct device *dev,
	180	struct device_attribute *attr,
	181	const char *buf, size_t count)
	182	{
	183	struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
	184	int val;
	185	int err;
	186	char *endp;
	187
	188	val = simple_strtoul(buf, &endp, 0);
	189	while (endp < buf + count && (endp == ' ' \|\| endp == '\n'))
	190	++endp;
	191	if (endp - buf < count)
	192	return -EINVAL;
	193	err = ctrl->ops->set_value(ctrl, val);
	194	if (err < 0)
	195	return err;
	196	return count;
	197	}
	198
75722d39 BH	199	int wf_register_control(struct wf_control *new_ct)
	200	{
	201	struct wf_control *ct;
	202
837e9594	203	mutex_lock(&wf_lock);
75722d39 BH	204	list_for_each_entry(ct, &wf_controls, link) {
	205	if (!strcmp(ct->name, new_ct->name)) {
	206	printk(KERN_WARNING "windfarm: trying to register"
	207	" duplicate control %s\n", ct->name);
837e9594	208	mutex_unlock(&wf_lock);
75722d39 BH	209	return -EEXIST;
	210	}
	211	}
	212	kref_init(&new_ct->ref);
	213	list_add(&new_ct->link, &wf_controls);
	214
ac171c46	215	new_ct->attr.attr.name = new_ct->name;
ac171c46 BH	216	new_ct->attr.attr.mode = 0644;
	217	new_ct->attr.show = wf_show_control;
	218	new_ct->attr.store = wf_store_control;
ccd308f0 SR	219	if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
	220	printk(KERN_WARNING "windfarm: device_create_file failed"
	221	" for %s\n", new_ct->name);
	222	/* the subsystem still does useful work without the file */
ac171c46	223
75722d39 BH	224	DBG("wf: Registered control %s\n", new_ct->name);
	225
	226	wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
837e9594	227	mutex_unlock(&wf_lock);
75722d39 BH	228
	229	return 0;
	230	}
	231	EXPORT_SYMBOL_GPL(wf_register_control);
	232
	233	void wf_unregister_control(struct wf_control *ct)
	234	{
837e9594	235	mutex_lock(&wf_lock);
75722d39	236	list_del(&ct->link);
837e9594	237	mutex_unlock(&wf_lock);
75722d39 BH	238
	239	DBG("wf: Unregistered control %s\n", ct->name);
	240
	241	kref_put(&ct->ref, wf_control_release);
	242	}
	243	EXPORT_SYMBOL_GPL(wf_unregister_control);
	244
	245	struct wf_control * wf_find_control(const char *name)
	246	{
	247	struct wf_control *ct;
	248
837e9594	249	mutex_lock(&wf_lock);
75722d39 BH	250	list_for_each_entry(ct, &wf_controls, link) {
	251	if (!strcmp(ct->name, name)) {
	252	if (wf_get_control(ct))
	253	ct = NULL;
837e9594	254	mutex_unlock(&wf_lock);
75722d39 BH	255	return ct;
	256	}
	257	}
837e9594	258	mutex_unlock(&wf_lock);
75722d39 BH	259	return NULL;
	260	}
	261	EXPORT_SYMBOL_GPL(wf_find_control);
	262
	263	int wf_get_control(struct wf_control *ct)
	264	{
	265	if (!try_module_get(ct->ops->owner))
	266	return -ENODEV;
	267	kref_get(&ct->ref);
	268	return 0;
	269	}
	270	EXPORT_SYMBOL_GPL(wf_get_control);
	271
	272	void wf_put_control(struct wf_control *ct)
	273	{
	274	struct module *mod = ct->ops->owner;
	275	kref_put(&ct->ref, wf_control_release);
	276	module_put(mod);
	277	}
	278	EXPORT_SYMBOL_GPL(wf_put_control);
	279
	280
	281	/*
	282	* Sensors
	283	*/
	284
	285
	286	static void wf_sensor_release(struct kref *kref)
	287	{
	288	struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
	289
	290	DBG("wf: Deleting sensor %s\n", sr->name);
	291
	292	if (sr->ops && sr->ops->release)
	293	sr->ops->release(sr);
	294	else
	295	kfree(sr);
	296	}
	297
ac171c46 BH	298	static ssize_t wf_show_sensor(struct device *dev,
	299	struct device_attribute attr, char buf)
	300	{
	301	struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
	302	s32 val = 0;
	303	int err;
	304
	305	err = sens->ops->get_value(sens, &val);
	306	if (err < 0)
	307	return err;
	308	return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
	309	}
	310
75722d39 BH	311	int wf_register_sensor(struct wf_sensor *new_sr)
	312	{
	313	struct wf_sensor *sr;
	314
837e9594	315	mutex_lock(&wf_lock);
75722d39 BH	316	list_for_each_entry(sr, &wf_sensors, link) {
	317	if (!strcmp(sr->name, new_sr->name)) {
	318	printk(KERN_WARNING "windfarm: trying to register"
	319	" duplicate sensor %s\n", sr->name);
837e9594	320	mutex_unlock(&wf_lock);
75722d39 BH	321	return -EEXIST;
	322	}
	323	}
	324	kref_init(&new_sr->ref);
	325	list_add(&new_sr->link, &wf_sensors);
	326
ac171c46	327	new_sr->attr.attr.name = new_sr->name;
ac171c46 BH	328	new_sr->attr.attr.mode = 0444;
	329	new_sr->attr.show = wf_show_sensor;
	330	new_sr->attr.store = NULL;
ccd308f0 SR	331	if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
	332	printk(KERN_WARNING "windfarm: device_create_file failed"
	333	" for %s\n", new_sr->name);
	334	/* the subsystem still does useful work without the file */
ac171c46	335
75722d39 BH	336	DBG("wf: Registered sensor %s\n", new_sr->name);
	337
	338	wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
837e9594	339	mutex_unlock(&wf_lock);
75722d39 BH	340
	341	return 0;
	342	}
	343	EXPORT_SYMBOL_GPL(wf_register_sensor);
	344
	345	void wf_unregister_sensor(struct wf_sensor *sr)
	346	{
837e9594	347	mutex_lock(&wf_lock);
75722d39	348	list_del(&sr->link);
837e9594	349	mutex_unlock(&wf_lock);
75722d39 BH	350
	351	DBG("wf: Unregistered sensor %s\n", sr->name);
	352
	353	wf_put_sensor(sr);
	354	}
	355	EXPORT_SYMBOL_GPL(wf_unregister_sensor);
	356
	357	struct wf_sensor * wf_find_sensor(const char *name)
	358	{
	359	struct wf_sensor *sr;
	360
837e9594	361	mutex_lock(&wf_lock);
75722d39 BH	362	list_for_each_entry(sr, &wf_sensors, link) {
	363	if (!strcmp(sr->name, name)) {
	364	if (wf_get_sensor(sr))
	365	sr = NULL;
837e9594	366	mutex_unlock(&wf_lock);
75722d39 BH	367	return sr;
	368	}
	369	}
837e9594	370	mutex_unlock(&wf_lock);
75722d39 BH	371	return NULL;
	372	}
	373	EXPORT_SYMBOL_GPL(wf_find_sensor);
	374
	375	int wf_get_sensor(struct wf_sensor *sr)
	376	{
	377	if (!try_module_get(sr->ops->owner))
	378	return -ENODEV;
	379	kref_get(&sr->ref);
	380	return 0;
	381	}
	382	EXPORT_SYMBOL_GPL(wf_get_sensor);
	383
	384	void wf_put_sensor(struct wf_sensor *sr)
	385	{
	386	struct module *mod = sr->ops->owner;
	387	kref_put(&sr->ref, wf_sensor_release);
	388	module_put(mod);
	389	}
	390	EXPORT_SYMBOL_GPL(wf_put_sensor);
	391
	392
	393	/*
	394	* Client & notification
	395	*/
	396
	397	int wf_register_client(struct notifier_block *nb)
	398	{
	399	int rc;
	400	struct wf_control *ct;
	401	struct wf_sensor *sr;
	402
837e9594	403	mutex_lock(&wf_lock);
e041c683	404	rc = blocking_notifier_chain_register(&wf_client_list, nb);
75722d39 BH	405	if (rc != 0)
	406	goto bail;
	407	wf_client_count++;
	408	list_for_each_entry(ct, &wf_controls, link)
	409	wf_notify(WF_EVENT_NEW_CONTROL, ct);
	410	list_for_each_entry(sr, &wf_sensors, link)
	411	wf_notify(WF_EVENT_NEW_SENSOR, sr);
	412	if (wf_client_count == 1)
	413	wf_start_thread();
	414	bail:
837e9594	415	mutex_unlock(&wf_lock);
75722d39 BH	416	return rc;
	417	}
	418	EXPORT_SYMBOL_GPL(wf_register_client);
	419
	420	int wf_unregister_client(struct notifier_block *nb)
	421	{
837e9594	422	mutex_lock(&wf_lock);
e041c683	423	blocking_notifier_chain_unregister(&wf_client_list, nb);
75722d39 BH	424	wf_client_count++;
	425	if (wf_client_count == 0)
	426	wf_stop_thread();
837e9594	427	mutex_unlock(&wf_lock);
75722d39 BH	428
	429	return 0;
	430	}
	431	EXPORT_SYMBOL_GPL(wf_unregister_client);
	432
	433	void wf_set_overtemp(void)
	434	{
837e9594	435	mutex_lock(&wf_lock);
75722d39 BH	436	wf_overtemp++;
	437	if (wf_overtemp == 1) {
	438	printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
	439	wf_overtemp_counter = 0;
	440	wf_notify(WF_EVENT_OVERTEMP, NULL);
	441	}
837e9594	442	mutex_unlock(&wf_lock);
75722d39 BH	443	}
	444	EXPORT_SYMBOL_GPL(wf_set_overtemp);
	445
	446	void wf_clear_overtemp(void)
	447	{
837e9594	448	mutex_lock(&wf_lock);
75722d39 BH	449	WARN_ON(wf_overtemp == 0);
75722d39 BH	450	if (wf_overtemp == 0) {
837e9594	451	mutex_unlock(&wf_lock);
75722d39 BH	452	return;
	453	}
	454	wf_overtemp--;
	455	if (wf_overtemp == 0) {
	456	printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
	457	wf_notify(WF_EVENT_NORMALTEMP, NULL);
	458	}
837e9594	459	mutex_unlock(&wf_lock);
75722d39 BH	460	}
	461	EXPORT_SYMBOL_GPL(wf_clear_overtemp);
	462
	463	int wf_is_overtemp(void)
	464	{
	465	return (wf_overtemp != 0);
	466	}
	467	EXPORT_SYMBOL_GPL(wf_is_overtemp);
	468
75722d39 BH	469	static int __init windfarm_core_init(void)
	470	{
	471	DBG("wf: core loaded\n");
	472
b55fafc5 BH	473	/* Don't register on old machines that use therm_pm72 for now */
	474	if (machine_is_compatible("PowerMac7,2") \|\|
	475	machine_is_compatible("PowerMac7,3") \|\|
	476	machine_is_compatible("RackMac3,1"))
	477	return -ENODEV;
75722d39 BH	478	platform_device_register(&wf_platform_device);
	479	return 0;
	480	}
	481
	482	static void __exit windfarm_core_exit(void)
	483	{
	484	BUG_ON(wf_client_count != 0);
	485
	486	DBG("wf: core unloaded\n");
	487
	488	platform_device_unregister(&wf_platform_device);
	489	}
	490
	491
	492	module_init(windfarm_core_init);
	493	module_exit(windfarm_core_exit);
	494
	495	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	496	MODULE_DESCRIPTION("Core component of PowerMac thermal control");
	497	MODULE_LICENSE("GPL");
	498