1 /* $NetBSD: nouveau_nvkm_subdev_therm_fan.c,v 1.4 2021/12/19 11:34:46 riastradh Exp $ */
2
3 /*
4 * Copyright 2012 Red Hat Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: Ben Skeggs
25 * Martin Peres
26 */
27 #include <sys/cdefs.h>
28 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_therm_fan.c,v 1.4 2021/12/19 11:34:46 riastradh Exp $");
29
30 #include "priv.h"
31
32 #include <subdev/bios/fan.h>
33 #include <subdev/gpio.h>
34 #include <subdev/timer.h>
35
36 static int
nvkm_fan_update(struct nvkm_fan * fan,bool immediate,int target)37 nvkm_fan_update(struct nvkm_fan *fan, bool immediate, int target)
38 {
39 struct nvkm_therm *therm = fan->parent;
40 struct nvkm_subdev *subdev = &therm->subdev;
41 struct nvkm_timer *tmr = subdev->device->timer;
42 unsigned long flags;
43 int ret = 0;
44 int duty;
45
46 /* update target fan speed, restricting to allowed range */
47 spin_lock_irqsave(&fan->lock, flags);
48 if (target < 0)
49 target = fan->percent;
50 target = max_t(u8, target, fan->bios.min_duty);
51 target = min_t(u8, target, fan->bios.max_duty);
52 if (fan->percent != target) {
53 #if 0 /* XXXMRG one log per second is a little excessive */
54 nvkm_debug(subdev, "FAN target: %d\n", target);
55 #endif
56 fan->percent = target;
57 }
58
59 /* check that we're not already at the target duty cycle */
60 duty = fan->get(therm);
61 if (duty == target) {
62 spin_unlock_irqrestore(&fan->lock, flags);
63 return 0;
64 }
65
66 /* smooth out the fanspeed increase/decrease */
67 if (!immediate && duty >= 0) {
68 /* the constant "3" is a rough approximation taken from
69 * nvidia's behaviour.
70 * it is meant to bump the fan speed more incrementally
71 */
72 if (duty < target)
73 duty = min(duty + 3, target);
74 else if (duty > target)
75 duty = max(duty - 3, target);
76 } else {
77 duty = target;
78 }
79
80 #if 0 /* XXXMRG one log per second is a little excessive */
81 nvkm_debug(subdev, "FAN update: %d\n", duty);
82 #endif
83 ret = fan->set(therm, duty);
84 if (ret) {
85 spin_unlock_irqrestore(&fan->lock, flags);
86 return ret;
87 }
88
89 /* fan speed updated, drop the fan lock before grabbing the
90 * alarm-scheduling lock and risking a deadlock
91 */
92 spin_unlock_irqrestore(&fan->lock, flags);
93
94 /* schedule next fan update, if not at target speed already */
95 if (target != duty) {
96 u16 bump_period = fan->bios.bump_period;
97 u16 slow_down_period = fan->bios.slow_down_period;
98 u64 delay;
99
100 if (duty > target)
101 delay = slow_down_period;
102 else if (duty == target)
103 delay = min(bump_period, slow_down_period) ;
104 else
105 delay = bump_period;
106
107 nvkm_timer_alarm(tmr, delay * 1000 * 1000, &fan->alarm);
108 }
109
110 return ret;
111 }
112
113 static void
nvkm_fan_alarm(struct nvkm_alarm * alarm)114 nvkm_fan_alarm(struct nvkm_alarm *alarm)
115 {
116 struct nvkm_fan *fan = container_of(alarm, struct nvkm_fan, alarm);
117 nvkm_fan_update(fan, false, -1);
118 }
119
120 int
nvkm_therm_fan_get(struct nvkm_therm * therm)121 nvkm_therm_fan_get(struct nvkm_therm *therm)
122 {
123 return therm->fan->get(therm);
124 }
125
126 int
nvkm_therm_fan_set(struct nvkm_therm * therm,bool immediate,int percent)127 nvkm_therm_fan_set(struct nvkm_therm *therm, bool immediate, int percent)
128 {
129 return nvkm_fan_update(therm->fan, immediate, percent);
130 }
131
132 int
nvkm_therm_fan_sense(struct nvkm_therm * therm)133 nvkm_therm_fan_sense(struct nvkm_therm *therm)
134 {
135 struct nvkm_device *device = therm->subdev.device;
136 struct nvkm_timer *tmr = device->timer;
137 struct nvkm_gpio *gpio = device->gpio;
138 u32 cycles, cur, prev;
139 u64 start, end, tach;
140
141 if (therm->func->fan_sense)
142 return therm->func->fan_sense(therm);
143
144 if (therm->fan->tach.func == DCB_GPIO_UNUSED)
145 return -ENODEV;
146
147 /* Time a complete rotation and extrapolate to RPM:
148 * When the fan spins, it changes the value of GPIO FAN_SENSE.
149 * We get 4 changes (0 -> 1 -> 0 -> 1) per complete rotation.
150 */
151 start = nvkm_timer_read(tmr);
152 prev = nvkm_gpio_get(gpio, 0, therm->fan->tach.func,
153 therm->fan->tach.line);
154 cycles = 0;
155 do {
156 usleep_range(500, 1000); /* supports 0 < rpm < 7500 */
157
158 cur = nvkm_gpio_get(gpio, 0, therm->fan->tach.func,
159 therm->fan->tach.line);
160 if (prev != cur) {
161 if (!start)
162 start = nvkm_timer_read(tmr);
163 cycles++;
164 prev = cur;
165 }
166 } while (cycles < 5 && nvkm_timer_read(tmr) - start < 250000000);
167 end = nvkm_timer_read(tmr);
168
169 if (cycles == 5) {
170 tach = (u64)60000000000ULL;
171 do_div(tach, (end - start));
172 return tach;
173 } else
174 return 0;
175 }
176
177 int
nvkm_therm_fan_user_get(struct nvkm_therm * therm)178 nvkm_therm_fan_user_get(struct nvkm_therm *therm)
179 {
180 return nvkm_therm_fan_get(therm);
181 }
182
183 int
nvkm_therm_fan_user_set(struct nvkm_therm * therm,int percent)184 nvkm_therm_fan_user_set(struct nvkm_therm *therm, int percent)
185 {
186 if (therm->mode != NVKM_THERM_CTRL_MANUAL)
187 return -EINVAL;
188
189 return nvkm_therm_fan_set(therm, true, percent);
190 }
191
192 static void
nvkm_therm_fan_set_defaults(struct nvkm_therm * therm)193 nvkm_therm_fan_set_defaults(struct nvkm_therm *therm)
194 {
195 therm->fan->bios.pwm_freq = 0;
196 therm->fan->bios.min_duty = 0;
197 therm->fan->bios.max_duty = 100;
198 therm->fan->bios.bump_period = 500;
199 therm->fan->bios.slow_down_period = 2000;
200 therm->fan->bios.linear_min_temp = 40;
201 therm->fan->bios.linear_max_temp = 85;
202 }
203
204 static void
nvkm_therm_fan_safety_checks(struct nvkm_therm * therm)205 nvkm_therm_fan_safety_checks(struct nvkm_therm *therm)
206 {
207 if (therm->fan->bios.min_duty > 100)
208 therm->fan->bios.min_duty = 100;
209 if (therm->fan->bios.max_duty > 100)
210 therm->fan->bios.max_duty = 100;
211
212 if (therm->fan->bios.min_duty > therm->fan->bios.max_duty)
213 therm->fan->bios.min_duty = therm->fan->bios.max_duty;
214 }
215
216 int
nvkm_therm_fan_init(struct nvkm_therm * therm)217 nvkm_therm_fan_init(struct nvkm_therm *therm)
218 {
219 return 0;
220 }
221
222 int
nvkm_therm_fan_fini(struct nvkm_therm * therm,bool suspend)223 nvkm_therm_fan_fini(struct nvkm_therm *therm, bool suspend)
224 {
225 struct nvkm_timer *tmr = therm->subdev.device->timer;
226 if (suspend)
227 nvkm_timer_alarm(tmr, 0, &therm->fan->alarm);
228 return 0;
229 }
230
231 void
nvkm_therm_fan_dtor(struct nvkm_therm * therm)232 nvkm_therm_fan_dtor(struct nvkm_therm *therm)
233 {
234 if (therm->fan->dtor)
235 therm->fan->dtor(therm->fan);
236 spin_lock_destroy(&therm->fan->lock);
237 }
238
239 int
nvkm_therm_fan_ctor(struct nvkm_therm * therm)240 nvkm_therm_fan_ctor(struct nvkm_therm *therm)
241 {
242 struct nvkm_subdev *subdev = &therm->subdev;
243 struct nvkm_device *device = subdev->device;
244 struct nvkm_gpio *gpio = device->gpio;
245 struct nvkm_bios *bios = device->bios;
246 struct dcb_gpio_func func;
247 int ret;
248
249 /* attempt to locate a drivable fan, and determine control method */
250 ret = nvkm_gpio_find(gpio, 0, DCB_GPIO_FAN, 0xff, &func);
251 if (ret == 0) {
252 /* FIXME: is this really the place to perform such checks ? */
253 if (func.line != 16 && func.log[0] & DCB_GPIO_LOG_DIR_IN) {
254 nvkm_debug(subdev, "GPIO_FAN is in input mode\n");
255 ret = -EINVAL;
256 } else {
257 ret = nvkm_fanpwm_create(therm, &func);
258 if (ret != 0)
259 ret = nvkm_fantog_create(therm, &func);
260 }
261 }
262
263 /* no controllable fan found, create a dummy fan module */
264 if (ret != 0) {
265 ret = nvkm_fannil_create(therm);
266 if (ret)
267 return ret;
268 }
269
270 nvkm_debug(subdev, "FAN control: %s\n", therm->fan->type);
271
272 /* read the current speed, it is useful when resuming */
273 therm->fan->percent = nvkm_therm_fan_get(therm);
274
275 /* attempt to detect a tachometer connection */
276 ret = nvkm_gpio_find(gpio, 0, DCB_GPIO_FAN_SENSE, 0xff,
277 &therm->fan->tach);
278 if (ret)
279 therm->fan->tach.func = DCB_GPIO_UNUSED;
280
281 /* initialise fan bump/slow update handling */
282 therm->fan->parent = therm;
283 nvkm_alarm_init(&therm->fan->alarm, nvkm_fan_alarm);
284 spin_lock_init(&therm->fan->lock);
285
286 /* other random init... */
287 nvkm_therm_fan_set_defaults(therm);
288 nvbios_perf_fan_parse(bios, &therm->fan->perf);
289 if (!nvbios_fan_parse(bios, &therm->fan->bios)) {
290 nvkm_debug(subdev, "parsing the fan table failed\n");
291 if (nvbios_therm_fan_parse(bios, &therm->fan->bios))
292 nvkm_error(subdev, "parsing both fan tables failed\n");
293 }
294 nvkm_therm_fan_safety_checks(therm);
295 return 0;
296 }
297