subdev/therm/fan.c

0001 /*
0002  * Copyright 2012 Red Hat Inc.
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice shall be included in
0012  * all copies or substantial portions of the Software.
0013  *
0014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0017  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
0018  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
0019  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
0020  * OTHER DEALINGS IN THE SOFTWARE.
0021  *
0022  * Authors: Ben Skeggs
0023  *      Martin Peres
0024  */
0025 #include "priv.h"
0026
0027 #include <subdev/bios/fan.h>
0028 #include <subdev/gpio.h>
0029 #include <subdev/timer.h>
0030
0031 static int
0032 nvkm_fan_update(struct nvkm_fan *fan, bool immediate, int target)
0033 {
0034     struct nvkm_therm *therm = fan->parent;
0035     struct nvkm_subdev *subdev = &therm->subdev;
0036     struct nvkm_timer *tmr = subdev->device->timer;
0037     unsigned long flags;
0038     int ret = 0;
0039     int duty;
0040
0041     /* update target fan speed, restricting to allowed range */
0042     spin_lock_irqsave(&fan->lock, flags);
0043     if (target < 0)
0044         target = fan->percent;
0045     target = max_t(u8, target, fan->bios.min_duty);
0046     target = min_t(u8, target, fan->bios.max_duty);
0047     if (fan->percent != target) {
0048         nvkm_debug(subdev, "FAN target: %d\n", target);
0049         fan->percent = target;
0050     }
0051
0052     /* check that we're not already at the target duty cycle */
0053     duty = fan->get(therm);
0054     if (duty == target) {
0055         spin_unlock_irqrestore(&fan->lock, flags);
0056         return 0;
0057     }
0058
0059     /* smooth out the fanspeed increase/decrease */
0060     if (!immediate && duty >= 0) {
0061         /* the constant "3" is a rough approximation taken from
0062          * nvidia's behaviour.
0063          * it is meant to bump the fan speed more incrementally
0064          */
0065         if (duty < target)
0066             duty = min(duty + 3, target);
0067         else if (duty > target)
0068             duty = max(duty - 3, target);
0069     } else {
0070         duty = target;
0071     }
0072
0073     nvkm_debug(subdev, "FAN update: %d\n", duty);
0074     ret = fan->set(therm, duty);
0075     if (ret) {
0076         spin_unlock_irqrestore(&fan->lock, flags);
0077         return ret;
0078     }
0079
0080     /* fan speed updated, drop the fan lock before grabbing the
0081      * alarm-scheduling lock and risking a deadlock
0082      */
0083     spin_unlock_irqrestore(&fan->lock, flags);
0084
0085     /* schedule next fan update, if not at target speed already */
0086     if (target != duty) {
0087         u16 bump_period = fan->bios.bump_period;
0088         u16 slow_down_period = fan->bios.slow_down_period;
0089         u64 delay;
0090
0091         if (duty > target)
0092             delay = slow_down_period;
0093         else if (duty == target)
0094             delay = min(bump_period, slow_down_period) ;
0095         else
0096             delay = bump_period;
0097
0098         nvkm_timer_alarm(tmr, delay * 1000 * 1000, &fan->alarm);
0099     }
0100
0101     return ret;
0102 }
0103
0104 static void
0105 nvkm_fan_alarm(struct nvkm_alarm *alarm)
0106 {
0107     struct nvkm_fan *fan = container_of(alarm, struct nvkm_fan, alarm);
0108     nvkm_fan_update(fan, false, -1);
0109 }
0110
0111 int
0112 nvkm_therm_fan_get(struct nvkm_therm *therm)
0113 {
0114     return therm->fan->get(therm);
0115 }
0116
0117 int
0118 nvkm_therm_fan_set(struct nvkm_therm *therm, bool immediate, int percent)
0119 {
0120     return nvkm_fan_update(therm->fan, immediate, percent);
0121 }
0122
0123 int
0124 nvkm_therm_fan_sense(struct nvkm_therm *therm)
0125 {
0126     struct nvkm_device *device = therm->subdev.device;
0127     struct nvkm_timer *tmr = device->timer;
0128     struct nvkm_gpio *gpio = device->gpio;
0129     u32 cycles, cur, prev;
0130     u64 start, end, tach;
0131
0132     if (therm->func->fan_sense)
0133         return therm->func->fan_sense(therm);
0134
0135     if (therm->fan->tach.func == DCB_GPIO_UNUSED)
0136         return -ENODEV;
0137
0138     /* Time a complete rotation and extrapolate to RPM:
0139      * When the fan spins, it changes the value of GPIO FAN_SENSE.
0140      * We get 4 changes (0 -> 1 -> 0 -> 1) per complete rotation.
0141      */
0142     start = nvkm_timer_read(tmr);
0143     prev = nvkm_gpio_get(gpio, 0, therm->fan->tach.func,
0144                       therm->fan->tach.line);
0145     cycles = 0;
0146     do {
0147         usleep_range(500, 1000); /* supports 0 < rpm < 7500 */
0148
0149         cur = nvkm_gpio_get(gpio, 0, therm->fan->tach.func,
0150                          therm->fan->tach.line);
0151         if (prev != cur) {
0152             if (!start)
0153                 start = nvkm_timer_read(tmr);
0154             cycles++;
0155             prev = cur;
0156         }
0157     } while (cycles < 5 && nvkm_timer_read(tmr) - start < 250000000);
0158     end = nvkm_timer_read(tmr);
0159
0160     if (cycles == 5) {
0161         tach = (u64)60000000000ULL;
0162         do_div(tach, (end - start));
0163         return tach;
0164     } else
0165         return 0;
0166 }
0167
0168 int
0169 nvkm_therm_fan_user_get(struct nvkm_therm *therm)
0170 {
0171     return nvkm_therm_fan_get(therm);
0172 }
0173
0174 int
0175 nvkm_therm_fan_user_set(struct nvkm_therm *therm, int percent)
0176 {
0177     if (therm->mode != NVKM_THERM_CTRL_MANUAL)
0178         return -EINVAL;
0179
0180     return nvkm_therm_fan_set(therm, true, percent);
0181 }
0182
0183 static void
0184 nvkm_therm_fan_set_defaults(struct nvkm_therm *therm)
0185 {
0186     therm->fan->bios.pwm_freq = 0;
0187     therm->fan->bios.min_duty = 0;
0188     therm->fan->bios.max_duty = 100;
0189     therm->fan->bios.bump_period = 500;
0190     therm->fan->bios.slow_down_period = 2000;
0191     therm->fan->bios.linear_min_temp = 40;
0192     therm->fan->bios.linear_max_temp = 85;
0193 }
0194
0195 static void
0196 nvkm_therm_fan_safety_checks(struct nvkm_therm *therm)
0197 {
0198     if (therm->fan->bios.min_duty > 100)
0199         therm->fan->bios.min_duty = 100;
0200     if (therm->fan->bios.max_duty > 100)
0201         therm->fan->bios.max_duty = 100;
0202
0203     if (therm->fan->bios.min_duty > therm->fan->bios.max_duty)
0204         therm->fan->bios.min_duty = therm->fan->bios.max_duty;
0205 }
0206
0207 int
0208 nvkm_therm_fan_init(struct nvkm_therm *therm)
0209 {
0210     return 0;
0211 }
0212
0213 int
0214 nvkm_therm_fan_fini(struct nvkm_therm *therm, bool suspend)
0215 {
0216     struct nvkm_timer *tmr = therm->subdev.device->timer;
0217     if (suspend)
0218         nvkm_timer_alarm(tmr, 0, &therm->fan->alarm);
0219     return 0;
0220 }
0221
0222 int
0223 nvkm_therm_fan_ctor(struct nvkm_therm *therm)
0224 {
0225     struct nvkm_subdev *subdev = &therm->subdev;
0226     struct nvkm_device *device = subdev->device;
0227     struct nvkm_gpio *gpio = device->gpio;
0228     struct nvkm_bios *bios = device->bios;
0229     struct dcb_gpio_func func;
0230     int ret;
0231
0232     /* attempt to locate a drivable fan, and determine control method */
0233     ret = nvkm_gpio_find(gpio, 0, DCB_GPIO_FAN, 0xff, &func);
0234     if (ret == 0) {
0235         /* FIXME: is this really the place to perform such checks ? */
0236         if (func.line != 16 && func.log[0] & DCB_GPIO_LOG_DIR_IN) {
0237             nvkm_debug(subdev, "GPIO_FAN is in input mode\n");
0238             ret = -EINVAL;
0239         } else {
0240             ret = nvkm_fanpwm_create(therm, &func);
0241             if (ret != 0)
0242                 ret = nvkm_fantog_create(therm, &func);
0243         }
0244     }
0245
0246     /* no controllable fan found, create a dummy fan module */
0247     if (ret != 0) {
0248         ret = nvkm_fannil_create(therm);
0249         if (ret)
0250             return ret;
0251     }
0252
0253     nvkm_debug(subdev, "FAN control: %s\n", therm->fan->type);
0254
0255     /* read the current speed, it is useful when resuming */
0256     therm->fan->percent = nvkm_therm_fan_get(therm);
0257
0258     /* attempt to detect a tachometer connection */
0259     ret = nvkm_gpio_find(gpio, 0, DCB_GPIO_FAN_SENSE, 0xff,
0260                  &therm->fan->tach);
0261     if (ret)
0262         therm->fan->tach.func = DCB_GPIO_UNUSED;
0263
0264     /* initialise fan bump/slow update handling */
0265     therm->fan->parent = therm;
0266     nvkm_alarm_init(&therm->fan->alarm, nvkm_fan_alarm);
0267     spin_lock_init(&therm->fan->lock);
0268
0269     /* other random init... */
0270     nvkm_therm_fan_set_defaults(therm);
0271     nvbios_perf_fan_parse(bios, &therm->fan->perf);
0272     if (!nvbios_fan_parse(bios, &therm->fan->bios)) {
0273         nvkm_debug(subdev, "parsing the fan table failed\n");
0274         if (nvbios_therm_fan_parse(bios, &therm->fan->bios))
0275             nvkm_error(subdev, "parsing both fan tables failed\n");
0276     }
0277     nvkm_therm_fan_safety_checks(therm);
0278     return 0;
0279 }