1 files changed, 461 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_core.c b/drivers/macintosh/windfarm_core.c
new file mode 100644
index 000000000..5307b1e34
--- /dev/null
+++ b/drivers/macintosh/windfarm_core.c
@@ -0,0 +1,461 @@
+// 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");
+