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