1 /* 2 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines. 3 * 4 * Copyright (C) 2010 LaCie 5 * 6 * Author: Simon Guinot <sguinot@lacie.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/slab.h> 26 #include <linux/interrupt.h> 27 #include <linux/irq.h> 28 #include <linux/platform_device.h> 29 #include <linux/err.h> 30 #include <linux/mutex.h> 31 #include <linux/hwmon.h> 32 #include <linux/gpio.h> 33 #include <linux/gpio-fan.h> 34 #include <linux/of.h> 35 #include <linux/of_platform.h> 36 #include <linux/of_gpio.h> 37 #include <linux/thermal.h> 38 39 struct gpio_fan_data { 40 struct platform_device *pdev; 41 struct device *hwmon_dev; 42 /* Cooling device if any */ 43 struct thermal_cooling_device *cdev; 44 struct mutex lock; /* lock GPIOs operations. */ 45 int num_ctrl; 46 unsigned *ctrl; 47 int num_speed; 48 struct gpio_fan_speed *speed; 49 int speed_index; 50 #ifdef CONFIG_PM_SLEEP 51 int resume_speed; 52 #endif 53 bool pwm_enable; 54 struct gpio_fan_alarm *alarm; 55 struct work_struct alarm_work; 56 }; 57 58 /* 59 * Alarm GPIO. 60 */ 61 62 static void fan_alarm_notify(struct work_struct *ws) 63 { 64 struct gpio_fan_data *fan_data = 65 container_of(ws, struct gpio_fan_data, alarm_work); 66 67 sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm"); 68 kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE); 69 } 70 71 static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id) 72 { 73 struct gpio_fan_data *fan_data = dev_id; 74 75 schedule_work(&fan_data->alarm_work); 76 77 return IRQ_NONE; 78 } 79 80 static ssize_t fan1_alarm_show(struct device *dev, 81 struct device_attribute *attr, char *buf) 82 { 83 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 84 struct gpio_fan_alarm *alarm = fan_data->alarm; 85 int value = gpio_get_value_cansleep(alarm->gpio); 86 87 if (alarm->active_low) 88 value = !value; 89 90 return sprintf(buf, "%d\n", value); 91 } 92 93 static DEVICE_ATTR_RO(fan1_alarm); 94 95 static int fan_alarm_init(struct gpio_fan_data *fan_data, 96 struct gpio_fan_alarm *alarm) 97 { 98 int err; 99 int alarm_irq; 100 struct platform_device *pdev = fan_data->pdev; 101 102 fan_data->alarm = alarm; 103 104 err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm"); 105 if (err) 106 return err; 107 108 err = gpio_direction_input(alarm->gpio); 109 if (err) 110 return err; 111 112 /* 113 * If the alarm GPIO don't support interrupts, just leave 114 * without initializing the fail notification support. 115 */ 116 alarm_irq = gpio_to_irq(alarm->gpio); 117 if (alarm_irq < 0) 118 return 0; 119 120 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify); 121 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH); 122 err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler, 123 IRQF_SHARED, "GPIO fan alarm", fan_data); 124 return err; 125 } 126 127 /* 128 * Control GPIOs. 129 */ 130 131 /* Must be called with fan_data->lock held, except during initialization. */ 132 static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val) 133 { 134 int i; 135 136 for (i = 0; i < fan_data->num_ctrl; i++) 137 gpio_set_value_cansleep(fan_data->ctrl[i], (ctrl_val >> i) & 1); 138 } 139 140 static int __get_fan_ctrl(struct gpio_fan_data *fan_data) 141 { 142 int i; 143 int ctrl_val = 0; 144 145 for (i = 0; i < fan_data->num_ctrl; i++) { 146 int value; 147 148 value = gpio_get_value_cansleep(fan_data->ctrl[i]); 149 ctrl_val |= (value << i); 150 } 151 return ctrl_val; 152 } 153 154 /* Must be called with fan_data->lock held, except during initialization. */ 155 static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index) 156 { 157 if (fan_data->speed_index == speed_index) 158 return; 159 160 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val); 161 fan_data->speed_index = speed_index; 162 } 163 164 static int get_fan_speed_index(struct gpio_fan_data *fan_data) 165 { 166 int ctrl_val = __get_fan_ctrl(fan_data); 167 int i; 168 169 for (i = 0; i < fan_data->num_speed; i++) 170 if (fan_data->speed[i].ctrl_val == ctrl_val) 171 return i; 172 173 dev_warn(&fan_data->pdev->dev, 174 "missing speed array entry for GPIO value 0x%x\n", ctrl_val); 175 176 return -ENODEV; 177 } 178 179 static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm) 180 { 181 struct gpio_fan_speed *speed = fan_data->speed; 182 int i; 183 184 for (i = 0; i < fan_data->num_speed; i++) 185 if (speed[i].rpm >= rpm) 186 return i; 187 188 return fan_data->num_speed - 1; 189 } 190 191 static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr, 192 char *buf) 193 { 194 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 195 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1); 196 197 return sprintf(buf, "%d\n", pwm); 198 } 199 200 static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr, 201 const char *buf, size_t count) 202 { 203 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 204 unsigned long pwm; 205 int speed_index; 206 int ret = count; 207 208 if (kstrtoul(buf, 10, &pwm) || pwm > 255) 209 return -EINVAL; 210 211 mutex_lock(&fan_data->lock); 212 213 if (!fan_data->pwm_enable) { 214 ret = -EPERM; 215 goto exit_unlock; 216 } 217 218 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255); 219 set_fan_speed(fan_data, speed_index); 220 221 exit_unlock: 222 mutex_unlock(&fan_data->lock); 223 224 return ret; 225 } 226 227 static ssize_t pwm1_enable_show(struct device *dev, 228 struct device_attribute *attr, char *buf) 229 { 230 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 231 232 return sprintf(buf, "%d\n", fan_data->pwm_enable); 233 } 234 235 static ssize_t pwm1_enable_store(struct device *dev, 236 struct device_attribute *attr, 237 const char *buf, size_t count) 238 { 239 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 240 unsigned long val; 241 242 if (kstrtoul(buf, 10, &val) || val > 1) 243 return -EINVAL; 244 245 if (fan_data->pwm_enable == val) 246 return count; 247 248 mutex_lock(&fan_data->lock); 249 250 fan_data->pwm_enable = val; 251 252 /* Disable manual control mode: set fan at full speed. */ 253 if (val == 0) 254 set_fan_speed(fan_data, fan_data->num_speed - 1); 255 256 mutex_unlock(&fan_data->lock); 257 258 return count; 259 } 260 261 static ssize_t pwm1_mode_show(struct device *dev, 262 struct device_attribute *attr, char *buf) 263 { 264 return sprintf(buf, "0\n"); 265 } 266 267 static ssize_t fan1_min_show(struct device *dev, 268 struct device_attribute *attr, char *buf) 269 { 270 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 271 272 return sprintf(buf, "%d\n", fan_data->speed[0].rpm); 273 } 274 275 static ssize_t fan1_max_show(struct device *dev, 276 struct device_attribute *attr, char *buf) 277 { 278 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 279 280 return sprintf(buf, "%d\n", 281 fan_data->speed[fan_data->num_speed - 1].rpm); 282 } 283 284 static ssize_t fan1_input_show(struct device *dev, 285 struct device_attribute *attr, char *buf) 286 { 287 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 288 289 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm); 290 } 291 292 static ssize_t set_rpm(struct device *dev, struct device_attribute *attr, 293 const char *buf, size_t count) 294 { 295 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 296 unsigned long rpm; 297 int ret = count; 298 299 if (kstrtoul(buf, 10, &rpm)) 300 return -EINVAL; 301 302 mutex_lock(&fan_data->lock); 303 304 if (!fan_data->pwm_enable) { 305 ret = -EPERM; 306 goto exit_unlock; 307 } 308 309 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm)); 310 311 exit_unlock: 312 mutex_unlock(&fan_data->lock); 313 314 return ret; 315 } 316 317 static DEVICE_ATTR_RW(pwm1); 318 static DEVICE_ATTR_RW(pwm1_enable); 319 static DEVICE_ATTR_RO(pwm1_mode); 320 static DEVICE_ATTR_RO(fan1_min); 321 static DEVICE_ATTR_RO(fan1_max); 322 static DEVICE_ATTR_RO(fan1_input); 323 static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, fan1_input_show, set_rpm); 324 325 static umode_t gpio_fan_is_visible(struct kobject *kobj, 326 struct attribute *attr, int index) 327 { 328 struct device *dev = container_of(kobj, struct device, kobj); 329 struct gpio_fan_data *data = dev_get_drvdata(dev); 330 331 if (index == 0 && !data->alarm) 332 return 0; 333 if (index > 0 && !data->ctrl) 334 return 0; 335 336 return attr->mode; 337 } 338 339 static struct attribute *gpio_fan_attributes[] = { 340 &dev_attr_fan1_alarm.attr, /* 0 */ 341 &dev_attr_pwm1.attr, /* 1 */ 342 &dev_attr_pwm1_enable.attr, 343 &dev_attr_pwm1_mode.attr, 344 &dev_attr_fan1_input.attr, 345 &dev_attr_fan1_target.attr, 346 &dev_attr_fan1_min.attr, 347 &dev_attr_fan1_max.attr, 348 NULL 349 }; 350 351 static const struct attribute_group gpio_fan_group = { 352 .attrs = gpio_fan_attributes, 353 .is_visible = gpio_fan_is_visible, 354 }; 355 356 static const struct attribute_group *gpio_fan_groups[] = { 357 &gpio_fan_group, 358 NULL 359 }; 360 361 static int fan_ctrl_init(struct gpio_fan_data *fan_data, 362 struct gpio_fan_platform_data *pdata) 363 { 364 struct platform_device *pdev = fan_data->pdev; 365 int num_ctrl = pdata->num_ctrl; 366 unsigned *ctrl = pdata->ctrl; 367 int i, err; 368 369 for (i = 0; i < num_ctrl; i++) { 370 err = devm_gpio_request(&pdev->dev, ctrl[i], 371 "GPIO fan control"); 372 if (err) 373 return err; 374 375 err = gpio_direction_output(ctrl[i], 376 gpio_get_value_cansleep(ctrl[i])); 377 if (err) 378 return err; 379 } 380 381 fan_data->num_ctrl = num_ctrl; 382 fan_data->ctrl = ctrl; 383 fan_data->num_speed = pdata->num_speed; 384 fan_data->speed = pdata->speed; 385 fan_data->pwm_enable = true; /* Enable manual fan speed control. */ 386 fan_data->speed_index = get_fan_speed_index(fan_data); 387 if (fan_data->speed_index < 0) 388 return fan_data->speed_index; 389 390 return 0; 391 } 392 393 static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev, 394 unsigned long *state) 395 { 396 struct gpio_fan_data *fan_data = cdev->devdata; 397 398 if (!fan_data) 399 return -EINVAL; 400 401 *state = fan_data->num_speed - 1; 402 return 0; 403 } 404 405 static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev, 406 unsigned long *state) 407 { 408 struct gpio_fan_data *fan_data = cdev->devdata; 409 410 if (!fan_data) 411 return -EINVAL; 412 413 *state = fan_data->speed_index; 414 return 0; 415 } 416 417 static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev, 418 unsigned long state) 419 { 420 struct gpio_fan_data *fan_data = cdev->devdata; 421 422 if (!fan_data) 423 return -EINVAL; 424 425 set_fan_speed(fan_data, state); 426 return 0; 427 } 428 429 static const struct thermal_cooling_device_ops gpio_fan_cool_ops = { 430 .get_max_state = gpio_fan_get_max_state, 431 .get_cur_state = gpio_fan_get_cur_state, 432 .set_cur_state = gpio_fan_set_cur_state, 433 }; 434 435 #ifdef CONFIG_OF_GPIO 436 /* 437 * Translate OpenFirmware node properties into platform_data 438 */ 439 static int gpio_fan_get_of_pdata(struct device *dev, 440 struct gpio_fan_platform_data *pdata) 441 { 442 struct device_node *node; 443 struct gpio_fan_speed *speed; 444 unsigned *ctrl; 445 unsigned i; 446 u32 u; 447 struct property *prop; 448 const __be32 *p; 449 450 node = dev->of_node; 451 452 /* Alarm GPIO if one exists */ 453 if (of_gpio_named_count(node, "alarm-gpios") > 0) { 454 struct gpio_fan_alarm *alarm; 455 int val; 456 enum of_gpio_flags flags; 457 458 alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm), 459 GFP_KERNEL); 460 if (!alarm) 461 return -ENOMEM; 462 463 val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags); 464 if (val < 0) 465 return val; 466 alarm->gpio = val; 467 alarm->active_low = flags & OF_GPIO_ACTIVE_LOW; 468 469 pdata->alarm = alarm; 470 } 471 472 /* Fill GPIO pin array */ 473 pdata->num_ctrl = of_gpio_count(node); 474 if (pdata->num_ctrl <= 0) { 475 if (pdata->alarm) 476 return 0; 477 dev_err(dev, "DT properties empty / missing"); 478 return -ENODEV; 479 } 480 ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned), 481 GFP_KERNEL); 482 if (!ctrl) 483 return -ENOMEM; 484 for (i = 0; i < pdata->num_ctrl; i++) { 485 int val; 486 487 val = of_get_gpio(node, i); 488 if (val < 0) 489 return val; 490 ctrl[i] = val; 491 } 492 pdata->ctrl = ctrl; 493 494 /* Get number of RPM/ctrl_val pairs in speed map */ 495 prop = of_find_property(node, "gpio-fan,speed-map", &i); 496 if (!prop) { 497 dev_err(dev, "gpio-fan,speed-map DT property missing"); 498 return -ENODEV; 499 } 500 i = i / sizeof(u32); 501 if (i == 0 || i & 1) { 502 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries"); 503 return -ENODEV; 504 } 505 pdata->num_speed = i / 2; 506 507 /* 508 * Populate speed map 509 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...> 510 * this needs splitting into pairs to create gpio_fan_speed structs 511 */ 512 speed = devm_kzalloc(dev, 513 pdata->num_speed * sizeof(struct gpio_fan_speed), 514 GFP_KERNEL); 515 if (!speed) 516 return -ENOMEM; 517 p = NULL; 518 for (i = 0; i < pdata->num_speed; i++) { 519 p = of_prop_next_u32(prop, p, &u); 520 if (!p) 521 return -ENODEV; 522 speed[i].rpm = u; 523 p = of_prop_next_u32(prop, p, &u); 524 if (!p) 525 return -ENODEV; 526 speed[i].ctrl_val = u; 527 } 528 pdata->speed = speed; 529 530 return 0; 531 } 532 533 static const struct of_device_id of_gpio_fan_match[] = { 534 { .compatible = "gpio-fan", }, 535 {}, 536 }; 537 MODULE_DEVICE_TABLE(of, of_gpio_fan_match); 538 #endif /* CONFIG_OF_GPIO */ 539 540 static int gpio_fan_probe(struct platform_device *pdev) 541 { 542 int err; 543 struct gpio_fan_data *fan_data; 544 struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev); 545 546 fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data), 547 GFP_KERNEL); 548 if (!fan_data) 549 return -ENOMEM; 550 551 #ifdef CONFIG_OF_GPIO 552 if (!pdata) { 553 pdata = devm_kzalloc(&pdev->dev, 554 sizeof(struct gpio_fan_platform_data), 555 GFP_KERNEL); 556 if (!pdata) 557 return -ENOMEM; 558 559 err = gpio_fan_get_of_pdata(&pdev->dev, pdata); 560 if (err) 561 return err; 562 } 563 #else /* CONFIG_OF_GPIO */ 564 if (!pdata) 565 return -EINVAL; 566 #endif /* CONFIG_OF_GPIO */ 567 568 fan_data->pdev = pdev; 569 platform_set_drvdata(pdev, fan_data); 570 mutex_init(&fan_data->lock); 571 572 /* Configure alarm GPIO if available. */ 573 if (pdata->alarm) { 574 err = fan_alarm_init(fan_data, pdata->alarm); 575 if (err) 576 return err; 577 } 578 579 /* Configure control GPIOs if available. */ 580 if (pdata->ctrl && pdata->num_ctrl > 0) { 581 if (!pdata->speed || pdata->num_speed <= 1) 582 return -EINVAL; 583 err = fan_ctrl_init(fan_data, pdata); 584 if (err) 585 return err; 586 } 587 588 /* Make this driver part of hwmon class. */ 589 fan_data->hwmon_dev = 590 devm_hwmon_device_register_with_groups(&pdev->dev, 591 "gpio_fan", fan_data, 592 gpio_fan_groups); 593 if (IS_ERR(fan_data->hwmon_dev)) 594 return PTR_ERR(fan_data->hwmon_dev); 595 #ifdef CONFIG_OF_GPIO 596 /* Optional cooling device register for Device tree platforms */ 597 fan_data->cdev = thermal_of_cooling_device_register(pdev->dev.of_node, 598 "gpio-fan", 599 fan_data, 600 &gpio_fan_cool_ops); 601 #else /* CONFIG_OF_GPIO */ 602 /* Optional cooling device register for non Device tree platforms */ 603 fan_data->cdev = thermal_cooling_device_register("gpio-fan", fan_data, 604 &gpio_fan_cool_ops); 605 #endif /* CONFIG_OF_GPIO */ 606 607 dev_info(&pdev->dev, "GPIO fan initialized\n"); 608 609 return 0; 610 } 611 612 static int gpio_fan_remove(struct platform_device *pdev) 613 { 614 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev); 615 616 if (!IS_ERR(fan_data->cdev)) 617 thermal_cooling_device_unregister(fan_data->cdev); 618 619 if (fan_data->ctrl) 620 set_fan_speed(fan_data, 0); 621 622 return 0; 623 } 624 625 static void gpio_fan_shutdown(struct platform_device *pdev) 626 { 627 gpio_fan_remove(pdev); 628 } 629 630 #ifdef CONFIG_PM_SLEEP 631 static int gpio_fan_suspend(struct device *dev) 632 { 633 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 634 635 if (fan_data->ctrl) { 636 fan_data->resume_speed = fan_data->speed_index; 637 set_fan_speed(fan_data, 0); 638 } 639 640 return 0; 641 } 642 643 static int gpio_fan_resume(struct device *dev) 644 { 645 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 646 647 if (fan_data->ctrl) 648 set_fan_speed(fan_data, fan_data->resume_speed); 649 650 return 0; 651 } 652 653 static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume); 654 #define GPIO_FAN_PM (&gpio_fan_pm) 655 #else 656 #define GPIO_FAN_PM NULL 657 #endif 658 659 static struct platform_driver gpio_fan_driver = { 660 .probe = gpio_fan_probe, 661 .remove = gpio_fan_remove, 662 .shutdown = gpio_fan_shutdown, 663 .driver = { 664 .name = "gpio-fan", 665 .pm = GPIO_FAN_PM, 666 #ifdef CONFIG_OF_GPIO 667 .of_match_table = of_match_ptr(of_gpio_fan_match), 668 #endif 669 }, 670 }; 671 672 module_platform_driver(gpio_fan_driver); 673 674 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>"); 675 MODULE_DESCRIPTION("GPIO FAN driver"); 676 MODULE_LICENSE("GPL"); 677 MODULE_ALIAS("platform:gpio-fan"); 678