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_priv *therm = (void *)fan->parent;
35 	struct nvkm_timer *tmr = nvkm_timer(therm);
36 	unsigned long flags;
37 	int ret = 0;
38 	int duty;
39 
40 	/* update target fan speed, restricting to allowed range */
41 	spin_lock_irqsave(&fan->lock, flags);
42 	if (target < 0)
43 		target = fan->percent;
44 	target = max_t(u8, target, fan->bios.min_duty);
45 	target = min_t(u8, target, fan->bios.max_duty);
46 	if (fan->percent != target) {
47 		nv_debug(therm, "FAN target: %d\n", target);
48 		fan->percent = target;
49 	}
50 
51 	/* check that we're not already at the target duty cycle */
52 	duty = fan->get(&therm->base);
53 	if (duty == target) {
54 		spin_unlock_irqrestore(&fan->lock, flags);
55 		return 0;
56 	}
57 
58 	/* smooth out the fanspeed increase/decrease */
59 	if (!immediate && duty >= 0) {
60 		/* the constant "3" is a rough approximation taken from
61 		 * nvidia's behaviour.
62 		 * it is meant to bump the fan speed more incrementally
63 		 */
64 		if (duty < target)
65 			duty = min(duty + 3, target);
66 		else if (duty > target)
67 			duty = max(duty - 3, target);
68 	} else {
69 		duty = target;
70 	}
71 
72 	nv_debug(therm, "FAN update: %d\n", duty);
73 	ret = fan->set(&therm->base, duty);
74 	if (ret) {
75 		spin_unlock_irqrestore(&fan->lock, flags);
76 		return ret;
77 	}
78 
79 	/* fan speed updated, drop the fan lock before grabbing the
80 	 * alarm-scheduling lock and risking a deadlock
81 	 */
82 	spin_unlock_irqrestore(&fan->lock, flags);
83 
84 	/* schedule next fan update, if not at target speed already */
85 	if (list_empty(&fan->alarm.head) && target != duty) {
86 		u16 bump_period = fan->bios.bump_period;
87 		u16 slow_down_period = fan->bios.slow_down_period;
88 		u64 delay;
89 
90 		if (duty > target)
91 			delay = slow_down_period;
92 		else if (duty == target)
93 			delay = min(bump_period, slow_down_period) ;
94 		else
95 			delay = bump_period;
96 
97 		tmr->alarm(tmr, delay * 1000 * 1000, &fan->alarm);
98 	}
99 
100 	return ret;
101 }
102 
103 static void
104 nvkm_fan_alarm(struct nvkm_alarm *alarm)
105 {
106 	struct nvkm_fan *fan = container_of(alarm, struct nvkm_fan, alarm);
107 	nvkm_fan_update(fan, false, -1);
108 }
109 
110 int
111 nvkm_therm_fan_get(struct nvkm_therm *obj)
112 {
113 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
114 	return therm->fan->get(&therm->base);
115 }
116 
117 int
118 nvkm_therm_fan_set(struct nvkm_therm *obj, bool immediate, int percent)
119 {
120 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
121 	return nvkm_fan_update(therm->fan, immediate, percent);
122 }
123 
124 int
125 nvkm_therm_fan_sense(struct nvkm_therm *obj)
126 {
127 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
128 	struct nvkm_timer *tmr = nvkm_timer(therm);
129 	struct nvkm_gpio *gpio = nvkm_gpio(therm);
130 	u32 cycles, cur, prev;
131 	u64 start, end, tach;
132 
133 	if (therm->fan->tach.func == DCB_GPIO_UNUSED)
134 		return -ENODEV;
135 
136 	/* Time a complete rotation and extrapolate to RPM:
137 	 * When the fan spins, it changes the value of GPIO FAN_SENSE.
138 	 * We get 4 changes (0 -> 1 -> 0 -> 1) per complete rotation.
139 	 */
140 	start = tmr->read(tmr);
141 	prev = gpio->get(gpio, 0, therm->fan->tach.func, therm->fan->tach.line);
142 	cycles = 0;
143 	do {
144 		usleep_range(500, 1000); /* supports 0 < rpm < 7500 */
145 
146 		cur = gpio->get(gpio, 0, therm->fan->tach.func, therm->fan->tach.line);
147 		if (prev != cur) {
148 			if (!start)
149 				start = tmr->read(tmr);
150 			cycles++;
151 			prev = cur;
152 		}
153 	} while (cycles < 5 && tmr->read(tmr) - start < 250000000);
154 	end = tmr->read(tmr);
155 
156 	if (cycles == 5) {
157 		tach = (u64)60000000000ULL;
158 		do_div(tach, (end - start));
159 		return tach;
160 	} else
161 		return 0;
162 }
163 
164 int
165 nvkm_therm_fan_user_get(struct nvkm_therm *obj)
166 {
167 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
168 	return nvkm_therm_fan_get(&therm->base);
169 }
170 
171 int
172 nvkm_therm_fan_user_set(struct nvkm_therm *obj, int percent)
173 {
174 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
175 
176 	if (therm->mode != NVKM_THERM_CTRL_MANUAL)
177 		return -EINVAL;
178 
179 	return nvkm_therm_fan_set(&therm->base, true, percent);
180 }
181 
182 static void
183 nvkm_therm_fan_set_defaults(struct nvkm_therm *obj)
184 {
185 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
186 
187 	therm->fan->bios.pwm_freq = 0;
188 	therm->fan->bios.min_duty = 0;
189 	therm->fan->bios.max_duty = 100;
190 	therm->fan->bios.bump_period = 500;
191 	therm->fan->bios.slow_down_period = 2000;
192 	therm->fan->bios.linear_min_temp = 40;
193 	therm->fan->bios.linear_max_temp = 85;
194 }
195 
196 static void
197 nvkm_therm_fan_safety_checks(struct nvkm_therm *obj)
198 {
199 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
200 
201 	if (therm->fan->bios.min_duty > 100)
202 		therm->fan->bios.min_duty = 100;
203 	if (therm->fan->bios.max_duty > 100)
204 		therm->fan->bios.max_duty = 100;
205 
206 	if (therm->fan->bios.min_duty > therm->fan->bios.max_duty)
207 		therm->fan->bios.min_duty = therm->fan->bios.max_duty;
208 }
209 
210 int
211 nvkm_therm_fan_init(struct nvkm_therm *obj)
212 {
213 	return 0;
214 }
215 
216 int
217 nvkm_therm_fan_fini(struct nvkm_therm *obj, bool suspend)
218 {
219 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
220 	struct nvkm_timer *tmr = nvkm_timer(therm);
221 
222 	if (suspend)
223 		tmr->alarm_cancel(tmr, &therm->fan->alarm);
224 	return 0;
225 }
226 
227 int
228 nvkm_therm_fan_ctor(struct nvkm_therm *obj)
229 {
230 	struct nvkm_therm_priv *therm = container_of(obj, typeof(*therm), base);
231 	struct nvkm_gpio *gpio = nvkm_gpio(therm);
232 	struct nvkm_bios *bios = nvkm_bios(therm);
233 	struct dcb_gpio_func func;
234 	int ret;
235 
236 	/* attempt to locate a drivable fan, and determine control method */
237 	ret = gpio->find(gpio, 0, DCB_GPIO_FAN, 0xff, &func);
238 	if (ret == 0) {
239 		/* FIXME: is this really the place to perform such checks ? */
240 		if (func.line != 16 && func.log[0] & DCB_GPIO_LOG_DIR_IN) {
241 			nv_debug(therm, "GPIO_FAN is in input mode\n");
242 			ret = -EINVAL;
243 		} else {
244 			ret = nvkm_fanpwm_create(&therm->base, &func);
245 			if (ret != 0)
246 				ret = nvkm_fantog_create(&therm->base, &func);
247 		}
248 	}
249 
250 	/* no controllable fan found, create a dummy fan module */
251 	if (ret != 0) {
252 		ret = nvkm_fannil_create(&therm->base);
253 		if (ret)
254 			return ret;
255 	}
256 
257 	nv_info(therm, "FAN control: %s\n", therm->fan->type);
258 
259 	/* read the current speed, it is useful when resuming */
260 	therm->fan->percent = nvkm_therm_fan_get(&therm->base);
261 
262 	/* attempt to detect a tachometer connection */
263 	ret = gpio->find(gpio, 0, DCB_GPIO_FAN_SENSE, 0xff, &therm->fan->tach);
264 	if (ret)
265 		therm->fan->tach.func = DCB_GPIO_UNUSED;
266 
267 	/* initialise fan bump/slow update handling */
268 	therm->fan->parent = &therm->base;
269 	nvkm_alarm_init(&therm->fan->alarm, nvkm_fan_alarm);
270 	spin_lock_init(&therm->fan->lock);
271 
272 	/* other random init... */
273 	nvkm_therm_fan_set_defaults(&therm->base);
274 	nvbios_perf_fan_parse(bios, &therm->fan->perf);
275 	if (!nvbios_fan_parse(bios, &therm->fan->bios)) {
276 		nv_debug(therm, "parsing the fan table failed\n");
277 		if (nvbios_therm_fan_parse(bios, &therm->fan->bios))
278 			nv_error(therm, "parsing both fan tables failed\n");
279 	}
280 	nvkm_therm_fan_safety_checks(&therm->base);
281 	return 0;
282 }
283