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