fan.c

  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
 31static int
 32nvkm_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 (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
104static void
105nvkm_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
111int
112nvkm_therm_fan_get(struct nvkm_therm *therm)
113{
114	return therm->fan->get(therm);
115}
116
117int
118nvkm_therm_fan_set(struct nvkm_therm *therm, bool immediate, int percent)
119{
120	return nvkm_fan_update(therm->fan, immediate, percent);
121}
122
123int
124nvkm_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
168int
169nvkm_therm_fan_user_get(struct nvkm_therm *therm)
170{
171	return nvkm_therm_fan_get(therm);
172}
173
174int
175nvkm_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
183static void
184nvkm_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
195static void
196nvkm_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
207int
208nvkm_therm_fan_init(struct nvkm_therm *therm)
209{
210	return 0;
211}
212
213int
214nvkm_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(tmr, 0, &therm->fan->alarm);
219	return 0;
220}
221
222int
223nvkm_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}