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_therm_priv *priv = (void *)therm;
  36         struct nvkm_timer *ptimer = nvkm_timer(priv);
  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                 nv_debug(therm, "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         nv_debug(therm, "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                 ptimer->alarm(ptimer, 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         struct nvkm_therm_priv *priv = (void *)therm;
 115         return priv->fan->get(therm);
 116 }
 117
 118 int
 119 nvkm_therm_fan_set(struct nvkm_therm *therm, bool immediate, int percent)
 120 {
 121         struct nvkm_therm_priv *priv = (void *)therm;
 122         return nvkm_fan_update(priv->fan, immediate, percent);
 123 }
 124
 125 int
 126 nvkm_therm_fan_sense(struct nvkm_therm *therm)
 127 {
 128         struct nvkm_therm_priv *priv = (void *)therm;
 129         struct nvkm_timer *ptimer = nvkm_timer(therm);
 130         struct nvkm_gpio *gpio = nvkm_gpio(therm);
 131         u32 cycles, cur, prev;
 132         u64 start, end, tach;
 133
 134         if (priv->fan->tach.func == DCB_GPIO_UNUSED)
 135                 return -ENODEV;
 136
 137         /* Time a complete rotation and extrapolate to RPM:
 138          * When the fan spins, it changes the value of GPIO FAN_SENSE.
 139          * We get 4 changes (0 -> 1 -> 0 -> 1) per complete rotation.
 140          */
 141         start = ptimer->read(ptimer);
 142         prev = gpio->get(gpio, 0, priv->fan->tach.func, priv->fan->tach.line);
 143         cycles = 0;
 144         do {
 145                 usleep_range(500, 1000); /* supports 0 < rpm < 7500 */
 146
 147                 cur = gpio->get(gpio, 0, priv->fan->tach.func, priv->fan->tach.line);
 148                 if (prev != cur) {
 149                         if (!start)
 150                                 start = ptimer->read(ptimer);
 151                         cycles++;
 152                         prev = cur;
 153                 }
 154         } while (cycles < 5 && ptimer->read(ptimer) - start < 250000000);
 155         end = ptimer->read(ptimer);
 156
 157         if (cycles == 5) {
 158                 tach = (u64)60000000000ULL;
 159                 do_div(tach, (end - start));
 160                 return tach;
 161         } else
 162                 return 0;
 163 }
 164
 165 int
 166 nvkm_therm_fan_user_get(struct nvkm_therm *therm)
 167 {
 168         return nvkm_therm_fan_get(therm);
 169 }
 170
 171 int
 172 nvkm_therm_fan_user_set(struct nvkm_therm *therm, int percent)
 173 {
 174         struct nvkm_therm_priv *priv = (void *)therm;
 175
 176         if (priv->mode != NVKM_THERM_CTRL_MANUAL)
 177                 return -EINVAL;
 178
 179         return nvkm_therm_fan_set(therm, true, percent);
 180 }
 181
 182 static void
 183 nvkm_therm_fan_set_defaults(struct nvkm_therm *therm)
 184 {
 185         struct nvkm_therm_priv *priv = (void *)therm;
 186
 187         priv->fan->bios.pwm_freq = 0;
 188         priv->fan->bios.min_duty = 0;
 189         priv->fan->bios.max_duty = 100;
 190         priv->fan->bios.bump_period = 500;
 191         priv->fan->bios.slow_down_period = 2000;
 192         priv->fan->bios.linear_min_temp = 40;
 193         priv->fan->bios.linear_max_temp = 85;
 194 }
 195
 196 static void
 197 nvkm_therm_fan_safety_checks(struct nvkm_therm *therm)
 198 {
 199         struct nvkm_therm_priv *priv = (void *)therm;
 200
 201         if (priv->fan->bios.min_duty > 100)
 202                 priv->fan->bios.min_duty = 100;
 203         if (priv->fan->bios.max_duty > 100)
 204                 priv->fan->bios.max_duty = 100;
 205
 206         if (priv->fan->bios.min_duty > priv->fan->bios.max_duty)
 207                 priv->fan->bios.min_duty = priv->fan->bios.max_duty;
 208 }
 209
 210 int
 211 nvkm_therm_fan_init(struct nvkm_therm *therm)
 212 {
 213         return 0;
 214 }
 215
 216 int
 217 nvkm_therm_fan_fini(struct nvkm_therm *therm, bool suspend)
 218 {
 219         struct nvkm_therm_priv *priv = (void *)therm;
 220         struct nvkm_timer *ptimer = nvkm_timer(therm);
 221
 222         if (suspend)
 223                 ptimer->alarm_cancel(ptimer, &priv->fan->alarm);
 224         return 0;
 225 }
 226
 227 int
 228 nvkm_therm_fan_ctor(struct nvkm_therm *therm)
 229 {
 230         struct nvkm_therm_priv *priv = (void *)therm;
 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, &func);
 245                         if (ret != 0)
 246                                 ret = nvkm_fantog_create(therm, &func);
 247                 }
 248         }
 249
 250         /* no controllable fan found, create a dummy fan module */
 251         if (ret != 0) {
 252                 ret = nvkm_fannil_create(therm);
 253                 if (ret)
 254                         return ret;
 255         }
 256
 257         nv_info(therm, "FAN control: %s\n", priv->fan->type);
 258
 259         /* read the current speed, it is useful when resuming */
 260         priv->fan->percent = nvkm_therm_fan_get(therm);
 261
 262         /* attempt to detect a tachometer connection */
 263         ret = gpio->find(gpio, 0, DCB_GPIO_FAN_SENSE, 0xff, &priv->fan->tach);
 264         if (ret)
 265                 priv->fan->tach.func = DCB_GPIO_UNUSED;
 266
 267         /* initialise fan bump/slow update handling */
 268         priv->fan->parent = therm;
 269         nvkm_alarm_init(&priv->fan->alarm, nvkm_fan_alarm);
 270         spin_lock_init(&priv->fan->lock);
 271
 272         /* other random init... */
 273         nvkm_therm_fan_set_defaults(therm);
 274         nvbios_perf_fan_parse(bios, &priv->fan->perf);
 275         if (!nvbios_fan_parse(bios, &priv->fan->bios)) {
 276                 nv_debug(therm, "parsing the fan table failed\n");
 277                 if (nvbios_therm_fan_parse(bios, &priv->fan->bios))
 278                         nv_error(therm, "parsing both fan tables failed\n");
 279         }
 280         nvkm_therm_fan_safety_checks(therm);
 281         return 0;
 282 }