[PATCH] ppc64: Thermal control for SMU based machines

This adds a new thermal control framework for PowerMac, along with the
implementation for PowerMac8,1, PowerMac8,2 (iMac G5 rev 1 and 2), and
PowerMac9,1 (latest single CPU desktop). In the future, I expect to move
the older G5 thermal control to the new framework as well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

drivers/macintosh/windfarm.h

@@ -0,0 +1,131 @@
+/*
+ * Windfarm PowerMac thermal control.
+ *
+ * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ * Released under the term of the GNU GPL v2.
+ */
+
+#ifndef __WINDFARM_H__
+#define __WINDFARM_H__
+
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+
+/* Display a 16.16 fixed point value */
+#define FIX32TOPRINT(f)	((f) >> 16),((((f) & 0xffff) * 1000) >> 16)
+
+/*
+ * Control objects
+ */
+
+struct wf_control;
+
+struct wf_control_ops {
+	int			(*set_value)(struct wf_control *ct, s32 val);
+	int			(*get_value)(struct wf_control *ct, s32 *val);
+	s32			(*get_min)(struct wf_control *ct);
+	s32			(*get_max)(struct wf_control *ct);
+	void			(*release)(struct wf_control *ct);
+	struct module		*owner;
+};
+
+struct wf_control {
+	struct list_head	link;
+	struct wf_control_ops	*ops;
+	char			*name;
+	int			type;
+	struct kref		ref;
+};
+
+#define WF_CONTROL_TYPE_GENERIC		0
+#define WF_CONTROL_RPM_FAN		1
+#define WF_CONTROL_PWM_FAN		2
+
+
+/* Note about lifetime rules: wf_register_control() will initialize
+ * the kref and wf_unregister_control will decrement it, thus the
+ * object creating/disposing a given control shouldn't assume it
+ * still exists after wf_unregister_control has been called.
+ * wf_find_control will inc the refcount for you
+ */
+extern int wf_register_control(struct wf_control *ct);
+extern void wf_unregister_control(struct wf_control *ct);
+extern struct wf_control * wf_find_control(const char *name);
+extern int wf_get_control(struct wf_control *ct);
+extern void wf_put_control(struct wf_control *ct);
+
+static inline int wf_control_set_max(struct wf_control *ct)
+{
+	s32 vmax = ct->ops->get_max(ct);
+	return ct->ops->set_value(ct, vmax);
+}
+
+static inline int wf_control_set_min(struct wf_control *ct)
+{
+	s32 vmin = ct->ops->get_min(ct);
+	return ct->ops->set_value(ct, vmin);
+}
+
+/*
+ * Sensor objects
+ */
+
+struct wf_sensor;
+
+struct wf_sensor_ops {
+	int			(*get_value)(struct wf_sensor *sr, s32 *val);
+	void			(*release)(struct wf_sensor *sr);
+	struct module		*owner;
+};
+
+struct wf_sensor {
+	struct list_head	link;
+	struct wf_sensor_ops	*ops;
+	char			*name;
+	struct kref		ref;
+};
+
+/* Same lifetime rules as controls */
+extern int wf_register_sensor(struct wf_sensor *sr);
+extern void wf_unregister_sensor(struct wf_sensor *sr);
+extern struct wf_sensor * wf_find_sensor(const char *name);
+extern int wf_get_sensor(struct wf_sensor *sr);
+extern void wf_put_sensor(struct wf_sensor *sr);
+
+/* For use by clients. Note that we are a bit racy here since
+ * notifier_block doesn't have a module owner field. I may fix
+ * it one day ...
+ *
+ * LOCKING NOTE !
+ *
+ * All "events" except WF_EVENT_TICK are called with an internal mutex
+ * held which will deadlock if you call basically any core routine.
+ * So don't ! Just take note of the event and do your actual operations
+ * from the ticker.
+ *
+ */
+extern int wf_register_client(struct notifier_block *nb);
+extern int wf_unregister_client(struct notifier_block *nb);
+
+/* Overtemp conditions. Those are refcounted */
+extern void wf_set_overtemp(void);
+extern void wf_clear_overtemp(void);
+extern int wf_is_overtemp(void);
+
+#define WF_EVENT_NEW_CONTROL	0 /* param is wf_control * */
+#define WF_EVENT_NEW_SENSOR	1 /* param is wf_sensor * */
+#define WF_EVENT_OVERTEMP	2 /* no param */
+#define WF_EVENT_NORMALTEMP	3 /* overtemp condition cleared */
+#define WF_EVENT_TICK		4 /* 1 second tick */
+
+/* Note: If that driver gets more broad use, we could replace the
+ * simplistic overtemp bits with "environmental conditions". That
+ * could then be used to also notify of things like fan failure,
+ * case open, battery conditions, ...
+ */
+
+#endif /* __WINDFARM_H__ */