1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2009-2011 Nathan Whitehorn
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/kernel.h>
34#include <sys/lock.h>
35#include <sys/mutex.h>
36#include <sys/systm.h>
37
38#include <sys/types.h>
39#include <sys/kthread.h>
40#include <sys/malloc.h>
41#include <sys/reboot.h>
42#include <sys/sysctl.h>
43#include <sys/queue.h>
44
45#include "powermac_thermal.h"
46
47/* A 10 second timer for spinning down fans. */
48#define FAN_HYSTERESIS_TIMER	10
49
50static void fan_management_proc(void);
51static void pmac_therm_manage_fans(void);
52
53static struct proc *pmac_them_proc;
54static int enable_pmac_thermal = 1;
55
56static struct kproc_desc pmac_therm_kp = {
57	"pmac_thermal",
58	fan_management_proc,
59	&pmac_them_proc
60};
61
62SYSINIT(pmac_therm_setup, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, kproc_start,
63    &pmac_therm_kp);
64SYSCTL_INT(_machdep, OID_AUTO, manage_fans, CTLFLAG_RW | CTLFLAG_TUN,
65    &enable_pmac_thermal, 1, "Enable automatic fan management");
66static MALLOC_DEFINE(M_PMACTHERM, "pmactherm", "Powermac Thermal Management");
67
68struct pmac_fan_le {
69	struct pmac_fan			*fan;
70	int				last_val;
71	int				timer;
72	SLIST_ENTRY(pmac_fan_le)	entries;
73};
74struct pmac_sens_le {
75	struct pmac_therm		*sensor;
76	int				last_val;
77#define MAX_CRITICAL_COUNT 6
78	int				critical_count;
79	SLIST_ENTRY(pmac_sens_le)	entries;
80};
81static SLIST_HEAD(pmac_fans, pmac_fan_le) fans = SLIST_HEAD_INITIALIZER(fans);
82static SLIST_HEAD(pmac_sensors, pmac_sens_le) sensors =
83    SLIST_HEAD_INITIALIZER(sensors);
84
85static void
86fan_management_proc(void)
87{
88	/* Nothing to manage? */
89	if (SLIST_EMPTY(&fans))
90		kproc_exit(0);
91
92	while (1) {
93		pmac_therm_manage_fans();
94		pause("pmac_therm", hz);
95	}
96}
97
98static void
99pmac_therm_manage_fans(void)
100{
101	struct pmac_sens_le *sensor;
102	struct pmac_fan_le *fan;
103	int average_excess, max_excess_zone, frac_excess;
104	int fan_speed;
105	int nsens, nsens_zone;
106	int temp;
107
108	if (!enable_pmac_thermal)
109		return;
110
111	/* Read all the sensors */
112	SLIST_FOREACH(sensor, &sensors, entries) {
113		temp = sensor->sensor->read(sensor->sensor);
114		if (temp > 0) /* Use the previous temp in case of error */
115			sensor->last_val = temp;
116
117		if (sensor->last_val > sensor->sensor->max_temp) {
118			sensor->critical_count++;
119			printf("WARNING: Current temperature (%s: %d.%d C) "
120			    "exceeds critical temperature (%d.%d C); "
121			    "count=%d\n",
122			    sensor->sensor->name,
123			    (sensor->last_val - ZERO_C_TO_K) / 10,
124			    (sensor->last_val - ZERO_C_TO_K) % 10,
125			    (sensor->sensor->max_temp - ZERO_C_TO_K) / 10,
126			    (sensor->sensor->max_temp - ZERO_C_TO_K) % 10,
127			    sensor->critical_count);
128			if (sensor->critical_count >= MAX_CRITICAL_COUNT) {
129				printf("WARNING: %s temperature exceeded "
130				    "critical temperature %d times in a row; "
131				    "shutting down!\n",
132				    sensor->sensor->name,
133				    sensor->critical_count);
134				shutdown_nice(RB_POWEROFF);
135			}
136		} else {
137			if (sensor->critical_count > 0)
138				sensor->critical_count--;
139		}
140	}
141
142	/* Set all the fans */
143	SLIST_FOREACH(fan, &fans, entries) {
144		nsens = nsens_zone = 0;
145		average_excess = max_excess_zone = 0;
146		SLIST_FOREACH(sensor, &sensors, entries) {
147			temp = imin(sensor->last_val,
148			    sensor->sensor->max_temp);
149			frac_excess = (temp -
150			    sensor->sensor->target_temp)*100 /
151			    (sensor->sensor->max_temp - temp + 1);
152			if (frac_excess < 0)
153				frac_excess = 0;
154			if (sensor->sensor->zone == fan->fan->zone) {
155				max_excess_zone = imax(max_excess_zone,
156				    frac_excess);
157				nsens_zone++;
158			}
159			average_excess += frac_excess;
160			nsens++;
161		}
162		average_excess /= nsens;
163
164		/* If there are no sensors in this zone, use the average */
165		if (nsens_zone == 0)
166			max_excess_zone = average_excess;
167		/* No sensors at all? Use default */
168		if (nsens == 0) {
169			fan->fan->set(fan->fan, fan->fan->default_rpm);
170			continue;
171		}
172
173		/*
174		 * Scale the fan linearly in the max temperature in its
175		 * thermal zone.
176		 */
177		max_excess_zone = imin(max_excess_zone, 100);
178		fan_speed = max_excess_zone *
179		    (fan->fan->max_rpm - fan->fan->min_rpm)/100 +
180		    fan->fan->min_rpm;
181		if (fan_speed >= fan->last_val) {
182		    fan->timer = FAN_HYSTERESIS_TIMER;
183		    fan->last_val = fan_speed;
184		} else {
185		    fan->timer--;
186		    if (fan->timer == 0) {
187		    	fan->last_val = fan_speed;
188		    	fan->timer = FAN_HYSTERESIS_TIMER;
189		    }
190		}
191		fan->fan->set(fan->fan, fan->last_val);
192	}
193}
194
195void
196pmac_thermal_fan_register(struct pmac_fan *fan)
197{
198	struct pmac_fan_le *list_entry;
199
200	list_entry = malloc(sizeof(struct pmac_fan_le), M_PMACTHERM,
201	    M_ZERO | M_WAITOK);
202	list_entry->fan = fan;
203
204	SLIST_INSERT_HEAD(&fans, list_entry, entries);
205}
206
207void
208pmac_thermal_sensor_register(struct pmac_therm *sensor)
209{
210	struct pmac_sens_le *list_entry;
211
212	list_entry = malloc(sizeof(struct pmac_sens_le), M_PMACTHERM,
213	    M_ZERO | M_WAITOK);
214	list_entry->sensor = sensor;
215	list_entry->last_val = 0;
216	list_entry->critical_count = 0;
217
218	SLIST_INSERT_HEAD(&sensors, list_entry, entries);
219}
220
221