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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Windfarm PowerMac thermal control. FCU fan control4 *5 * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.6 */7#undef DEBUG8 9#include <linux/types.h>10#include <linux/errno.h>11#include <linux/kernel.h>12#include <linux/delay.h>13#include <linux/slab.h>14#include <linux/init.h>15#include <linux/wait.h>16#include <linux/i2c.h>17 18#include <asm/machdep.h>19#include <asm/io.h>20#include <asm/sections.h>21 22#include "windfarm.h"23#include "windfarm_mpu.h"24 25#define VERSION "1.0"26 27#ifdef DEBUG28#define DBG(args...) printk(args)29#else30#define DBG(args...) do { } while(0)31#endif32 33/*34 * This option is "weird" :) Basically, if you define this to 135 * the control loop for the RPMs fans (not PWMs) will apply the36 * correction factor obtained from the PID to the actual RPM37 * speed read from the FCU.38 *39 * If you define the below constant to 0, then it will be40 * applied to the setpoint RPM speed, that is basically the41 * speed we proviously "asked" for.42 *43 * I'm using 0 for now which is what therm_pm72 used to do and44 * what Darwin -apparently- does based on observed behaviour.45 */46#define RPM_PID_USE_ACTUAL_SPEED 047 48/* Default min/max for pumps */49#define CPU_PUMP_OUTPUT_MAX 320050#define CPU_PUMP_OUTPUT_MIN 125051 52#define FCU_FAN_RPM 053#define FCU_FAN_PWM 154 55struct wf_fcu_priv {56 struct kref ref;57 struct i2c_client *i2c;58 struct mutex lock;59 struct list_head fan_list;60 int rpm_shift;61};62 63struct wf_fcu_fan {64 struct list_head link;65 int id;66 s32 min, max, target;67 struct wf_fcu_priv *fcu_priv;68 struct wf_control ctrl;69};70 71static void wf_fcu_release(struct kref *ref)72{73 struct wf_fcu_priv *pv = container_of(ref, struct wf_fcu_priv, ref);74 75 kfree(pv);76}77 78static void wf_fcu_fan_release(struct wf_control *ct)79{80 struct wf_fcu_fan *fan = ct->priv;81 82 kref_put(&fan->fcu_priv->ref, wf_fcu_release);83 kfree(fan);84}85 86static int wf_fcu_read_reg(struct wf_fcu_priv *pv, int reg,87 unsigned char *buf, int nb)88{89 int tries, nr, nw;90 91 mutex_lock(&pv->lock);92 93 buf[0] = reg;94 tries = 0;95 for (;;) {96 nw = i2c_master_send(pv->i2c, buf, 1);97 if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)98 break;99 msleep(10);100 ++tries;101 }102 if (nw <= 0) {103 pr_err("Failure writing address to FCU: %d", nw);104 nr = nw;105 goto bail;106 }107 tries = 0;108 for (;;) {109 nr = i2c_master_recv(pv->i2c, buf, nb);110 if (nr > 0 || (nr < 0 && nr != -ENODEV) || tries >= 100)111 break;112 msleep(10);113 ++tries;114 }115 if (nr <= 0)116 pr_err("wf_fcu: Failure reading data from FCU: %d", nw);117 bail:118 mutex_unlock(&pv->lock);119 return nr;120}121 122static int wf_fcu_write_reg(struct wf_fcu_priv *pv, int reg,123 const unsigned char *ptr, int nb)124{125 int tries, nw;126 unsigned char buf[16];127 128 buf[0] = reg;129 memcpy(buf+1, ptr, nb);130 ++nb;131 tries = 0;132 for (;;) {133 nw = i2c_master_send(pv->i2c, buf, nb);134 if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)135 break;136 msleep(10);137 ++tries;138 }139 if (nw < 0)140 pr_err("wf_fcu: Failure writing to FCU: %d", nw);141 return nw;142}143 144static int wf_fcu_fan_set_rpm(struct wf_control *ct, s32 value)145{146 struct wf_fcu_fan *fan = ct->priv;147 struct wf_fcu_priv *pv = fan->fcu_priv;148 int rc, shift = pv->rpm_shift;149 unsigned char buf[2];150 151 if (value < fan->min)152 value = fan->min;153 if (value > fan->max)154 value = fan->max;155 156 fan->target = value;157 158 buf[0] = value >> (8 - shift);159 buf[1] = value << shift;160 rc = wf_fcu_write_reg(pv, 0x10 + (fan->id * 2), buf, 2);161 if (rc < 0)162 return -EIO;163 return 0;164}165 166static int wf_fcu_fan_get_rpm(struct wf_control *ct, s32 *value)167{168 struct wf_fcu_fan *fan = ct->priv;169 struct wf_fcu_priv *pv = fan->fcu_priv;170 int rc, reg_base, shift = pv->rpm_shift;171 unsigned char failure;172 unsigned char active;173 unsigned char buf[2];174 175 rc = wf_fcu_read_reg(pv, 0xb, &failure, 1);176 if (rc != 1)177 return -EIO;178 if ((failure & (1 << fan->id)) != 0)179 return -EFAULT;180 rc = wf_fcu_read_reg(pv, 0xd, &active, 1);181 if (rc != 1)182 return -EIO;183 if ((active & (1 << fan->id)) == 0)184 return -ENXIO;185 186 /* Programmed value or real current speed */187#if RPM_PID_USE_ACTUAL_SPEED188 reg_base = 0x11;189#else190 reg_base = 0x10;191#endif192 rc = wf_fcu_read_reg(pv, reg_base + (fan->id * 2), buf, 2);193 if (rc != 2)194 return -EIO;195 196 *value = (buf[0] << (8 - shift)) | buf[1] >> shift;197 198 return 0;199}200 201static int wf_fcu_fan_set_pwm(struct wf_control *ct, s32 value)202{203 struct wf_fcu_fan *fan = ct->priv;204 struct wf_fcu_priv *pv = fan->fcu_priv;205 unsigned char buf[2];206 int rc;207 208 if (value < fan->min)209 value = fan->min;210 if (value > fan->max)211 value = fan->max;212 213 fan->target = value;214 215 value = (value * 2559) / 1000;216 buf[0] = value;217 rc = wf_fcu_write_reg(pv, 0x30 + (fan->id * 2), buf, 1);218 if (rc < 0)219 return -EIO;220 return 0;221}222 223static int wf_fcu_fan_get_pwm(struct wf_control *ct, s32 *value)224{225 struct wf_fcu_fan *fan = ct->priv;226 struct wf_fcu_priv *pv = fan->fcu_priv;227 unsigned char failure;228 unsigned char active;229 unsigned char buf[2];230 int rc;231 232 rc = wf_fcu_read_reg(pv, 0x2b, &failure, 1);233 if (rc != 1)234 return -EIO;235 if ((failure & (1 << fan->id)) != 0)236 return -EFAULT;237 rc = wf_fcu_read_reg(pv, 0x2d, &active, 1);238 if (rc != 1)239 return -EIO;240 if ((active & (1 << fan->id)) == 0)241 return -ENXIO;242 243 rc = wf_fcu_read_reg(pv, 0x30 + (fan->id * 2), buf, 1);244 if (rc != 1)245 return -EIO;246 247 *value = (((s32)buf[0]) * 1000) / 2559;248 249 return 0;250}251 252static s32 wf_fcu_fan_min(struct wf_control *ct)253{254 struct wf_fcu_fan *fan = ct->priv;255 256 return fan->min;257}258 259static s32 wf_fcu_fan_max(struct wf_control *ct)260{261 struct wf_fcu_fan *fan = ct->priv;262 263 return fan->max;264}265 266static const struct wf_control_ops wf_fcu_fan_rpm_ops = {267 .set_value = wf_fcu_fan_set_rpm,268 .get_value = wf_fcu_fan_get_rpm,269 .get_min = wf_fcu_fan_min,270 .get_max = wf_fcu_fan_max,271 .release = wf_fcu_fan_release,272 .owner = THIS_MODULE,273};274 275static const struct wf_control_ops wf_fcu_fan_pwm_ops = {276 .set_value = wf_fcu_fan_set_pwm,277 .get_value = wf_fcu_fan_get_pwm,278 .get_min = wf_fcu_fan_min,279 .get_max = wf_fcu_fan_max,280 .release = wf_fcu_fan_release,281 .owner = THIS_MODULE,282};283 284static void wf_fcu_get_pump_minmax(struct wf_fcu_fan *fan)285{286 const struct mpu_data *mpu = wf_get_mpu(0);287 u16 pump_min = 0, pump_max = 0xffff;288 u16 tmp[4];289 290 /* Try to fetch pumps min/max infos from eeprom */291 if (mpu) {292 memcpy(&tmp, mpu->processor_part_num, 8);293 if (tmp[0] != 0xffff && tmp[1] != 0xffff) {294 pump_min = max(pump_min, tmp[0]);295 pump_max = min(pump_max, tmp[1]);296 }297 if (tmp[2] != 0xffff && tmp[3] != 0xffff) {298 pump_min = max(pump_min, tmp[2]);299 pump_max = min(pump_max, tmp[3]);300 }301 }302 303 /* Double check the values, this _IS_ needed as the EEPROM on304 * some dual 2.5Ghz G5s seem, at least, to have both min & max305 * same to the same value ... (grrrr)306 */307 if (pump_min == pump_max || pump_min == 0 || pump_max == 0xffff) {308 pump_min = CPU_PUMP_OUTPUT_MIN;309 pump_max = CPU_PUMP_OUTPUT_MAX;310 }311 312 fan->min = pump_min;313 fan->max = pump_max;314 315 DBG("wf_fcu: pump min/max for %s set to: [%d..%d] RPM\n",316 fan->ctrl.name, pump_min, pump_max);317}318 319static void wf_fcu_get_rpmfan_minmax(struct wf_fcu_fan *fan)320{321 struct wf_fcu_priv *pv = fan->fcu_priv;322 const struct mpu_data *mpu0 = wf_get_mpu(0);323 const struct mpu_data *mpu1 = wf_get_mpu(1);324 325 /* Default */326 fan->min = 2400 >> pv->rpm_shift;327 fan->max = 56000 >> pv->rpm_shift;328 329 /* CPU fans have min/max in MPU */330 if (mpu0 && !strcmp(fan->ctrl.name, "cpu-front-fan-0")) {331 fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);332 fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);333 goto bail;334 }335 if (mpu1 && !strcmp(fan->ctrl.name, "cpu-front-fan-1")) {336 fan->min = max(fan->min, (s32)mpu1->rminn_intake_fan);337 fan->max = min(fan->max, (s32)mpu1->rmaxn_intake_fan);338 goto bail;339 }340 if (mpu0 && !strcmp(fan->ctrl.name, "cpu-rear-fan-0")) {341 fan->min = max(fan->min, (s32)mpu0->rminn_exhaust_fan);342 fan->max = min(fan->max, (s32)mpu0->rmaxn_exhaust_fan);343 goto bail;344 }345 if (mpu1 && !strcmp(fan->ctrl.name, "cpu-rear-fan-1")) {346 fan->min = max(fan->min, (s32)mpu1->rminn_exhaust_fan);347 fan->max = min(fan->max, (s32)mpu1->rmaxn_exhaust_fan);348 goto bail;349 }350 /* Rackmac variants, we just use mpu0 intake */351 if (!strncmp(fan->ctrl.name, "cpu-fan", 7)) {352 fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);353 fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);354 goto bail;355 }356 bail:357 DBG("wf_fcu: fan min/max for %s set to: [%d..%d] RPM\n",358 fan->ctrl.name, fan->min, fan->max);359}360 361static void wf_fcu_add_fan(struct wf_fcu_priv *pv, const char *name,362 int type, int id)363{364 struct wf_fcu_fan *fan;365 366 fan = kzalloc(sizeof(*fan), GFP_KERNEL);367 if (!fan)368 return;369 fan->fcu_priv = pv;370 fan->id = id;371 fan->ctrl.name = name;372 fan->ctrl.priv = fan;373 374 /* min/max is oddball but the code comes from375 * therm_pm72 which seems to work so ...376 */377 if (type == FCU_FAN_RPM) {378 if (!strncmp(name, "cpu-pump", strlen("cpu-pump")))379 wf_fcu_get_pump_minmax(fan);380 else381 wf_fcu_get_rpmfan_minmax(fan);382 fan->ctrl.type = WF_CONTROL_RPM_FAN;383 fan->ctrl.ops = &wf_fcu_fan_rpm_ops;384 } else {385 fan->min = 10;386 fan->max = 100;387 fan->ctrl.type = WF_CONTROL_PWM_FAN;388 fan->ctrl.ops = &wf_fcu_fan_pwm_ops;389 }390 391 if (wf_register_control(&fan->ctrl)) {392 pr_err("wf_fcu: Failed to register fan %s\n", name);393 kfree(fan);394 return;395 }396 list_add(&fan->link, &pv->fan_list);397 kref_get(&pv->ref);398}399 400static void wf_fcu_lookup_fans(struct wf_fcu_priv *pv)401{402 /* Translation of device-tree location properties to403 * windfarm fan names404 */405 static const struct {406 const char *dt_name; /* Device-tree name */407 const char *ct_name; /* Control name */408 } loc_trans[] = {409 { "BACKSIDE", "backside-fan", },410 { "SYS CTRLR FAN", "backside-fan", },411 { "DRIVE BAY", "drive-bay-fan", },412 { "SLOT", "slots-fan", },413 { "PCI FAN", "slots-fan", },414 { "CPU A INTAKE", "cpu-front-fan-0", },415 { "CPU A EXHAUST", "cpu-rear-fan-0", },416 { "CPU B INTAKE", "cpu-front-fan-1", },417 { "CPU B EXHAUST", "cpu-rear-fan-1", },418 { "CPU A PUMP", "cpu-pump-0", },419 { "CPU B PUMP", "cpu-pump-1", },420 { "CPU A 1", "cpu-fan-a-0", },421 { "CPU A 2", "cpu-fan-b-0", },422 { "CPU A 3", "cpu-fan-c-0", },423 { "CPU B 1", "cpu-fan-a-1", },424 { "CPU B 2", "cpu-fan-b-1", },425 { "CPU B 3", "cpu-fan-c-1", },426 };427 struct device_node *np, *fcu = pv->i2c->dev.of_node;428 int i;429 430 DBG("Looking up FCU controls in device-tree...\n");431 432 for_each_child_of_node(fcu, np) {433 int id, type = -1;434 const char *loc;435 const char *name;436 const u32 *reg;437 438 DBG(" control: %pOFn, type: %s\n", np, of_node_get_device_type(np));439 440 /* Detect control type */441 if (of_node_is_type(np, "fan-rpm-control") ||442 of_node_is_type(np, "fan-rpm"))443 type = FCU_FAN_RPM;444 if (of_node_is_type(np, "fan-pwm-control") ||445 of_node_is_type(np, "fan-pwm"))446 type = FCU_FAN_PWM;447 /* Only care about fans for now */448 if (type == -1)449 continue;450 451 /* Lookup for a matching location */452 loc = of_get_property(np, "location", NULL);453 reg = of_get_property(np, "reg", NULL);454 if (loc == NULL || reg == NULL)455 continue;456 DBG(" matching location: %s, reg: 0x%08x\n", loc, *reg);457 458 for (i = 0; i < ARRAY_SIZE(loc_trans); i++) {459 if (strncmp(loc, loc_trans[i].dt_name,460 strlen(loc_trans[i].dt_name)))461 continue;462 name = loc_trans[i].ct_name;463 464 DBG(" location match, name: %s\n", name);465 466 if (type == FCU_FAN_RPM)467 id = ((*reg) - 0x10) / 2;468 else469 id = ((*reg) - 0x30) / 2;470 if (id > 7) {471 pr_warn("wf_fcu: Can't parse fan ID in device-tree for %pOF\n", np);472 break;473 }474 wf_fcu_add_fan(pv, name, type, id);475 break;476 }477 }478}479 480static void wf_fcu_default_fans(struct wf_fcu_priv *pv)481{482 /* We only support the default fans for PowerMac7,2 */483 if (!of_machine_is_compatible("PowerMac7,2"))484 return;485 486 wf_fcu_add_fan(pv, "backside-fan", FCU_FAN_PWM, 1);487 wf_fcu_add_fan(pv, "drive-bay-fan", FCU_FAN_RPM, 2);488 wf_fcu_add_fan(pv, "slots-fan", FCU_FAN_PWM, 2);489 wf_fcu_add_fan(pv, "cpu-front-fan-0", FCU_FAN_RPM, 3);490 wf_fcu_add_fan(pv, "cpu-rear-fan-0", FCU_FAN_RPM, 4);491 wf_fcu_add_fan(pv, "cpu-front-fan-1", FCU_FAN_RPM, 5);492 wf_fcu_add_fan(pv, "cpu-rear-fan-1", FCU_FAN_RPM, 6);493}494 495static int wf_fcu_init_chip(struct wf_fcu_priv *pv)496{497 unsigned char buf = 0xff;498 int rc;499 500 rc = wf_fcu_write_reg(pv, 0xe, &buf, 1);501 if (rc < 0)502 return -EIO;503 rc = wf_fcu_write_reg(pv, 0x2e, &buf, 1);504 if (rc < 0)505 return -EIO;506 rc = wf_fcu_read_reg(pv, 0, &buf, 1);507 if (rc < 0)508 return -EIO;509 pv->rpm_shift = (buf == 1) ? 2 : 3;510 511 pr_debug("wf_fcu: FCU Initialized, RPM fan shift is %d\n",512 pv->rpm_shift);513 514 return 0;515}516 517static int wf_fcu_probe(struct i2c_client *client)518{519 struct wf_fcu_priv *pv;520 521 pv = kzalloc(sizeof(*pv), GFP_KERNEL);522 if (!pv)523 return -ENOMEM;524 525 kref_init(&pv->ref);526 mutex_init(&pv->lock);527 INIT_LIST_HEAD(&pv->fan_list);528 pv->i2c = client;529 530 /*531 * First we must start the FCU which will query the532 * shift value to apply to RPMs533 */534 if (wf_fcu_init_chip(pv)) {535 pr_err("wf_fcu: Initialization failed !\n");536 kfree(pv);537 return -ENXIO;538 }539 540 /* First lookup fans in the device-tree */541 wf_fcu_lookup_fans(pv);542 543 /*544 * Older machines don't have the device-tree entries545 * we are looking for, just hard code the list546 */547 if (list_empty(&pv->fan_list))548 wf_fcu_default_fans(pv);549 550 /* Still no fans ? FAIL */551 if (list_empty(&pv->fan_list)) {552 pr_err("wf_fcu: Failed to find fans for your machine\n");553 kfree(pv);554 return -ENODEV;555 }556 557 dev_set_drvdata(&client->dev, pv);558 559 return 0;560}561 562static void wf_fcu_remove(struct i2c_client *client)563{564 struct wf_fcu_priv *pv = dev_get_drvdata(&client->dev);565 struct wf_fcu_fan *fan;566 567 while (!list_empty(&pv->fan_list)) {568 fan = list_first_entry(&pv->fan_list, struct wf_fcu_fan, link);569 list_del(&fan->link);570 wf_unregister_control(&fan->ctrl);571 }572 kref_put(&pv->ref, wf_fcu_release);573}574 575static const struct i2c_device_id wf_fcu_id[] = {576 { "MAC,fcu" },577 { }578};579MODULE_DEVICE_TABLE(i2c, wf_fcu_id);580 581static const struct of_device_id wf_fcu_of_id[] = {582 { .compatible = "fcu", },583 { }584};585MODULE_DEVICE_TABLE(of, wf_fcu_of_id);586 587static struct i2c_driver wf_fcu_driver = {588 .driver = {589 .name = "wf_fcu",590 .of_match_table = wf_fcu_of_id,591 },592 .probe = wf_fcu_probe,593 .remove = wf_fcu_remove,594 .id_table = wf_fcu_id,595};596 597module_i2c_driver(wf_fcu_driver);598 599MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");600MODULE_DESCRIPTION("FCU control objects for PowerMacs thermal control");601MODULE_LICENSE("GPL");602 603