linux/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fan.c
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   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 (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
 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_cancel(tmr, &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}
 280