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 show_fan_alarm(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(fan1_alarm, S_IRUGO, show_fan_alarm, NULL); 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 show_pwm(struct device *dev, 192 struct device_attribute *attr, 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 set_pwm(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 show_pwm_enable(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 set_pwm_enable(struct device *dev, struct device_attribute *attr, 236 const char *buf, size_t count) 237 { 238 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 239 unsigned long val; 240 241 if (kstrtoul(buf, 10, &val) || val > 1) 242 return -EINVAL; 243 244 if (fan_data->pwm_enable == val) 245 return count; 246 247 mutex_lock(&fan_data->lock); 248 249 fan_data->pwm_enable = val; 250 251 /* Disable manual control mode: set fan at full speed. */ 252 if (val == 0) 253 set_fan_speed(fan_data, fan_data->num_speed - 1); 254 255 mutex_unlock(&fan_data->lock); 256 257 return count; 258 } 259 260 static ssize_t show_pwm_mode(struct device *dev, 261 struct device_attribute *attr, char *buf) 262 { 263 return sprintf(buf, "0\n"); 264 } 265 266 static ssize_t show_rpm_min(struct device *dev, 267 struct device_attribute *attr, char *buf) 268 { 269 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 270 271 return sprintf(buf, "%d\n", fan_data->speed[0].rpm); 272 } 273 274 static ssize_t show_rpm_max(struct device *dev, 275 struct device_attribute *attr, char *buf) 276 { 277 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 278 279 return sprintf(buf, "%d\n", 280 fan_data->speed[fan_data->num_speed - 1].rpm); 281 } 282 283 static ssize_t show_rpm(struct device *dev, 284 struct device_attribute *attr, char *buf) 285 { 286 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 287 288 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm); 289 } 290 291 static ssize_t set_rpm(struct device *dev, struct device_attribute *attr, 292 const char *buf, size_t count) 293 { 294 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 295 unsigned long rpm; 296 int ret = count; 297 298 if (kstrtoul(buf, 10, &rpm)) 299 return -EINVAL; 300 301 mutex_lock(&fan_data->lock); 302 303 if (!fan_data->pwm_enable) { 304 ret = -EPERM; 305 goto exit_unlock; 306 } 307 308 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm)); 309 310 exit_unlock: 311 mutex_unlock(&fan_data->lock); 312 313 return ret; 314 } 315 316 static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm); 317 static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR, 318 show_pwm_enable, set_pwm_enable); 319 static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL); 320 static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL); 321 static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL); 322 static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL); 323 static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, 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 int r; 410 411 if (!fan_data) 412 return -EINVAL; 413 414 r = get_fan_speed_index(fan_data); 415 if (r < 0) 416 return r; 417 418 *state = r; 419 return 0; 420 } 421 422 static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev, 423 unsigned long state) 424 { 425 struct gpio_fan_data *fan_data = cdev->devdata; 426 427 if (!fan_data) 428 return -EINVAL; 429 430 set_fan_speed(fan_data, state); 431 return 0; 432 } 433 434 static const struct thermal_cooling_device_ops gpio_fan_cool_ops = { 435 .get_max_state = gpio_fan_get_max_state, 436 .get_cur_state = gpio_fan_get_cur_state, 437 .set_cur_state = gpio_fan_set_cur_state, 438 }; 439 440 #ifdef CONFIG_OF_GPIO 441 /* 442 * Translate OpenFirmware node properties into platform_data 443 */ 444 static int gpio_fan_get_of_pdata(struct device *dev, 445 struct gpio_fan_platform_data *pdata) 446 { 447 struct device_node *node; 448 struct gpio_fan_speed *speed; 449 unsigned *ctrl; 450 unsigned i; 451 u32 u; 452 struct property *prop; 453 const __be32 *p; 454 455 node = dev->of_node; 456 457 /* Alarm GPIO if one exists */ 458 if (of_gpio_named_count(node, "alarm-gpios") > 0) { 459 struct gpio_fan_alarm *alarm; 460 int val; 461 enum of_gpio_flags flags; 462 463 alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm), 464 GFP_KERNEL); 465 if (!alarm) 466 return -ENOMEM; 467 468 val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags); 469 if (val < 0) 470 return val; 471 alarm->gpio = val; 472 alarm->active_low = flags & OF_GPIO_ACTIVE_LOW; 473 474 pdata->alarm = alarm; 475 } 476 477 /* Fill GPIO pin array */ 478 pdata->num_ctrl = of_gpio_count(node); 479 if (pdata->num_ctrl <= 0) { 480 if (pdata->alarm) 481 return 0; 482 dev_err(dev, "DT properties empty / missing"); 483 return -ENODEV; 484 } 485 ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned), 486 GFP_KERNEL); 487 if (!ctrl) 488 return -ENOMEM; 489 for (i = 0; i < pdata->num_ctrl; i++) { 490 int val; 491 492 val = of_get_gpio(node, i); 493 if (val < 0) 494 return val; 495 ctrl[i] = val; 496 } 497 pdata->ctrl = ctrl; 498 499 /* Get number of RPM/ctrl_val pairs in speed map */ 500 prop = of_find_property(node, "gpio-fan,speed-map", &i); 501 if (!prop) { 502 dev_err(dev, "gpio-fan,speed-map DT property missing"); 503 return -ENODEV; 504 } 505 i = i / sizeof(u32); 506 if (i == 0 || i & 1) { 507 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries"); 508 return -ENODEV; 509 } 510 pdata->num_speed = i / 2; 511 512 /* 513 * Populate speed map 514 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...> 515 * this needs splitting into pairs to create gpio_fan_speed structs 516 */ 517 speed = devm_kzalloc(dev, 518 pdata->num_speed * sizeof(struct gpio_fan_speed), 519 GFP_KERNEL); 520 if (!speed) 521 return -ENOMEM; 522 p = NULL; 523 for (i = 0; i < pdata->num_speed; i++) { 524 p = of_prop_next_u32(prop, p, &u); 525 if (!p) 526 return -ENODEV; 527 speed[i].rpm = u; 528 p = of_prop_next_u32(prop, p, &u); 529 if (!p) 530 return -ENODEV; 531 speed[i].ctrl_val = u; 532 } 533 pdata->speed = speed; 534 535 return 0; 536 } 537 538 static const struct of_device_id of_gpio_fan_match[] = { 539 { .compatible = "gpio-fan", }, 540 {}, 541 }; 542 MODULE_DEVICE_TABLE(of, of_gpio_fan_match); 543 #endif /* CONFIG_OF_GPIO */ 544 545 static int gpio_fan_probe(struct platform_device *pdev) 546 { 547 int err; 548 struct gpio_fan_data *fan_data; 549 struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev); 550 551 fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data), 552 GFP_KERNEL); 553 if (!fan_data) 554 return -ENOMEM; 555 556 #ifdef CONFIG_OF_GPIO 557 if (!pdata) { 558 pdata = devm_kzalloc(&pdev->dev, 559 sizeof(struct gpio_fan_platform_data), 560 GFP_KERNEL); 561 if (!pdata) 562 return -ENOMEM; 563 564 err = gpio_fan_get_of_pdata(&pdev->dev, pdata); 565 if (err) 566 return err; 567 } 568 #else /* CONFIG_OF_GPIO */ 569 if (!pdata) 570 return -EINVAL; 571 #endif /* CONFIG_OF_GPIO */ 572 573 fan_data->pdev = pdev; 574 platform_set_drvdata(pdev, fan_data); 575 mutex_init(&fan_data->lock); 576 577 /* Configure alarm GPIO if available. */ 578 if (pdata->alarm) { 579 err = fan_alarm_init(fan_data, pdata->alarm); 580 if (err) 581 return err; 582 } 583 584 /* Configure control GPIOs if available. */ 585 if (pdata->ctrl && pdata->num_ctrl > 0) { 586 if (!pdata->speed || pdata->num_speed <= 1) 587 return -EINVAL; 588 err = fan_ctrl_init(fan_data, pdata); 589 if (err) 590 return err; 591 } 592 593 /* Make this driver part of hwmon class. */ 594 fan_data->hwmon_dev = 595 devm_hwmon_device_register_with_groups(&pdev->dev, 596 "gpio_fan", fan_data, 597 gpio_fan_groups); 598 if (IS_ERR(fan_data->hwmon_dev)) 599 return PTR_ERR(fan_data->hwmon_dev); 600 #ifdef CONFIG_OF_GPIO 601 /* Optional cooling device register for Device tree platforms */ 602 fan_data->cdev = thermal_of_cooling_device_register(pdev->dev.of_node, 603 "gpio-fan", 604 fan_data, 605 &gpio_fan_cool_ops); 606 #else /* CONFIG_OF_GPIO */ 607 /* Optional cooling device register for non Device tree platforms */ 608 fan_data->cdev = thermal_cooling_device_register("gpio-fan", fan_data, 609 &gpio_fan_cool_ops); 610 #endif /* CONFIG_OF_GPIO */ 611 612 dev_info(&pdev->dev, "GPIO fan initialized\n"); 613 614 return 0; 615 } 616 617 static int gpio_fan_remove(struct platform_device *pdev) 618 { 619 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev); 620 621 if (!IS_ERR(fan_data->cdev)) 622 thermal_cooling_device_unregister(fan_data->cdev); 623 624 if (fan_data->ctrl) 625 set_fan_speed(fan_data, 0); 626 627 return 0; 628 } 629 630 static void gpio_fan_shutdown(struct platform_device *pdev) 631 { 632 gpio_fan_remove(pdev); 633 } 634 635 #ifdef CONFIG_PM_SLEEP 636 static int gpio_fan_suspend(struct device *dev) 637 { 638 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 639 640 if (fan_data->ctrl) { 641 fan_data->resume_speed = fan_data->speed_index; 642 set_fan_speed(fan_data, 0); 643 } 644 645 return 0; 646 } 647 648 static int gpio_fan_resume(struct device *dev) 649 { 650 struct gpio_fan_data *fan_data = dev_get_drvdata(dev); 651 652 if (fan_data->ctrl) 653 set_fan_speed(fan_data, fan_data->resume_speed); 654 655 return 0; 656 } 657 658 static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume); 659 #define GPIO_FAN_PM (&gpio_fan_pm) 660 #else 661 #define GPIO_FAN_PM NULL 662 #endif 663 664 static struct platform_driver gpio_fan_driver = { 665 .probe = gpio_fan_probe, 666 .remove = gpio_fan_remove, 667 .shutdown = gpio_fan_shutdown, 668 .driver = { 669 .name = "gpio-fan", 670 .pm = GPIO_FAN_PM, 671 #ifdef CONFIG_OF_GPIO 672 .of_match_table = of_match_ptr(of_gpio_fan_match), 673 #endif 674 }, 675 }; 676 677 module_platform_driver(gpio_fan_driver); 678 679 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>"); 680 MODULE_DESCRIPTION("GPIO FAN driver"); 681 MODULE_LICENSE("GPL"); 682 MODULE_ALIAS("platform:gpio-fan"); 683