summaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/windfarm_core.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/macintosh/windfarm_core.c')
-rw-r--r--drivers/macintosh/windfarm_core.c461
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");
+