kernel/drivers/gpu/drm/nouveau/nvkm/subdev/therm/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
  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 }