1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * GPIO testing driver based on configfs. 4 * 5 * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl> 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/bitmap.h> 11 #include <linux/cleanup.h> 12 #include <linux/completion.h> 13 #include <linux/configfs.h> 14 #include <linux/device.h> 15 #include <linux/gpio/driver.h> 16 #include <linux/gpio/machine.h> 17 #include <linux/idr.h> 18 #include <linux/interrupt.h> 19 #include <linux/irq.h> 20 #include <linux/irq_sim.h> 21 #include <linux/list.h> 22 #include <linux/minmax.h> 23 #include <linux/mod_devicetable.h> 24 #include <linux/module.h> 25 #include <linux/mutex.h> 26 #include <linux/notifier.h> 27 #include <linux/platform_device.h> 28 #include <linux/property.h> 29 #include <linux/slab.h> 30 #include <linux/string.h> 31 #include <linux/string_helpers.h> 32 #include <linux/sysfs.h> 33 34 #include "gpiolib.h" 35 36 #define GPIO_SIM_NGPIO_MAX 1024 37 #define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */ 38 #define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */ 39 40 static DEFINE_IDA(gpio_sim_ida); 41 42 struct gpio_sim_chip { 43 struct gpio_chip gc; 44 unsigned long *direction_map; 45 unsigned long *value_map; 46 unsigned long *pull_map; 47 struct irq_domain *irq_sim; 48 struct mutex lock; 49 const struct attribute_group **attr_groups; 50 }; 51 52 struct gpio_sim_attribute { 53 struct device_attribute dev_attr; 54 unsigned int offset; 55 }; 56 57 static struct gpio_sim_attribute * 58 to_gpio_sim_attr(struct device_attribute *dev_attr) 59 { 60 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 61 } 62 63 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 64 unsigned int offset, int value) 65 { 66 int irq, irq_type, ret; 67 struct gpio_desc *desc; 68 struct gpio_chip *gc; 69 70 gc = &chip->gc; 71 desc = &gc->gpiodev->descs[offset]; 72 73 guard(mutex)(&chip->lock); 74 75 if (test_bit(FLAG_REQUESTED, &desc->flags) && 76 !test_bit(FLAG_IS_OUT, &desc->flags)) { 77 if (value == !!test_bit(offset, chip->value_map)) 78 goto set_pull; 79 80 /* 81 * This is fine - it just means, nobody is listening 82 * for interrupts on this line, otherwise 83 * irq_create_mapping() would have been called from 84 * the to_irq() callback. 85 */ 86 irq = irq_find_mapping(chip->irq_sim, offset); 87 if (!irq) 88 goto set_value; 89 90 irq_type = irq_get_trigger_type(irq); 91 92 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) || 93 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) { 94 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 95 true); 96 if (ret) 97 goto set_pull; 98 } 99 } 100 101 set_value: 102 /* Change the value unless we're actively driving the line. */ 103 if (!test_bit(FLAG_REQUESTED, &desc->flags) || 104 !test_bit(FLAG_IS_OUT, &desc->flags)) 105 __assign_bit(offset, chip->value_map, value); 106 107 set_pull: 108 __assign_bit(offset, chip->pull_map, value); 109 return 0; 110 } 111 112 static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset) 113 { 114 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 115 116 guard(mutex)(&chip->lock); 117 118 return !!test_bit(offset, chip->value_map); 119 } 120 121 static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value) 122 { 123 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 124 125 scoped_guard(mutex, &chip->lock) 126 __assign_bit(offset, chip->value_map, value); 127 } 128 129 static int gpio_sim_get_multiple(struct gpio_chip *gc, 130 unsigned long *mask, unsigned long *bits) 131 { 132 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 133 134 scoped_guard(mutex, &chip->lock) 135 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 136 137 return 0; 138 } 139 140 static void gpio_sim_set_multiple(struct gpio_chip *gc, 141 unsigned long *mask, unsigned long *bits) 142 { 143 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 144 145 scoped_guard(mutex, &chip->lock) 146 bitmap_replace(chip->value_map, chip->value_map, bits, mask, 147 gc->ngpio); 148 } 149 150 static int gpio_sim_direction_output(struct gpio_chip *gc, 151 unsigned int offset, int value) 152 { 153 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 154 155 scoped_guard(mutex, &chip->lock) { 156 __clear_bit(offset, chip->direction_map); 157 __assign_bit(offset, chip->value_map, value); 158 } 159 160 return 0; 161 } 162 163 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 164 { 165 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 166 167 scoped_guard(mutex, &chip->lock) 168 __set_bit(offset, chip->direction_map); 169 170 return 0; 171 } 172 173 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 174 { 175 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 176 int direction; 177 178 scoped_guard(mutex, &chip->lock) 179 direction = !!test_bit(offset, chip->direction_map); 180 181 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; 182 } 183 184 static int gpio_sim_set_config(struct gpio_chip *gc, 185 unsigned int offset, unsigned long config) 186 { 187 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 188 189 switch (pinconf_to_config_param(config)) { 190 case PIN_CONFIG_BIAS_PULL_UP: 191 return gpio_sim_apply_pull(chip, offset, 1); 192 case PIN_CONFIG_BIAS_PULL_DOWN: 193 return gpio_sim_apply_pull(chip, offset, 0); 194 default: 195 break; 196 } 197 198 return -ENOTSUPP; 199 } 200 201 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 202 { 203 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 204 205 return irq_create_mapping(chip->irq_sim, offset); 206 } 207 208 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 209 { 210 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 211 212 scoped_guard(mutex, &chip->lock) 213 __assign_bit(offset, chip->value_map, 214 !!test_bit(offset, chip->pull_map)); 215 } 216 217 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 218 struct device_attribute *attr, char *buf) 219 { 220 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 221 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 222 int val; 223 224 scoped_guard(mutex, &chip->lock) 225 val = !!test_bit(line_attr->offset, chip->value_map); 226 227 return sysfs_emit(buf, "%d\n", val); 228 } 229 230 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 231 struct device_attribute *attr, 232 const char *buf, size_t count) 233 { 234 /* 235 * Not assigning this function will result in write() returning -EIO 236 * which is confusing. Return -EPERM explicitly. 237 */ 238 return -EPERM; 239 } 240 241 static const char *const gpio_sim_sysfs_pull_strings[] = { 242 [0] = "pull-down", 243 [1] = "pull-up", 244 }; 245 246 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 247 struct device_attribute *attr, 248 char *buf) 249 { 250 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 251 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 252 int pull; 253 254 scoped_guard(mutex, &chip->lock) 255 pull = !!test_bit(line_attr->offset, chip->pull_map); 256 257 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 258 } 259 260 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 261 struct device_attribute *attr, 262 const char *buf, size_t len) 263 { 264 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 265 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 266 int ret, pull; 267 268 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 269 if (pull < 0) 270 return pull; 271 272 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 273 if (ret) 274 return ret; 275 276 return len; 277 } 278 279 static void gpio_sim_mutex_destroy(void *data) 280 { 281 struct mutex *lock = data; 282 283 mutex_destroy(lock); 284 } 285 286 static void gpio_sim_dispose_mappings(void *data) 287 { 288 struct gpio_sim_chip *chip = data; 289 unsigned int i; 290 291 for (i = 0; i < chip->gc.ngpio; i++) 292 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 293 } 294 295 static void gpio_sim_sysfs_remove(void *data) 296 { 297 struct gpio_sim_chip *chip = data; 298 299 sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups); 300 } 301 302 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 303 { 304 struct device_attribute *val_dev_attr, *pull_dev_attr; 305 struct gpio_sim_attribute *val_attr, *pull_attr; 306 unsigned int num_lines = chip->gc.ngpio; 307 struct device *dev = chip->gc.parent; 308 struct attribute_group *attr_group; 309 struct attribute **attrs; 310 int i, ret; 311 312 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 313 num_lines + 1, GFP_KERNEL); 314 if (!chip->attr_groups) 315 return -ENOMEM; 316 317 for (i = 0; i < num_lines; i++) { 318 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 319 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 320 GFP_KERNEL); 321 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 322 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 323 if (!attr_group || !attrs || !val_attr || !pull_attr) 324 return -ENOMEM; 325 326 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 327 "sim_gpio%u", i); 328 if (!attr_group->name) 329 return -ENOMEM; 330 331 val_attr->offset = pull_attr->offset = i; 332 333 val_dev_attr = &val_attr->dev_attr; 334 pull_dev_attr = &pull_attr->dev_attr; 335 336 sysfs_attr_init(&val_dev_attr->attr); 337 sysfs_attr_init(&pull_dev_attr->attr); 338 339 val_dev_attr->attr.name = "value"; 340 pull_dev_attr->attr.name = "pull"; 341 342 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 343 344 val_dev_attr->show = gpio_sim_sysfs_val_show; 345 val_dev_attr->store = gpio_sim_sysfs_val_store; 346 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 347 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 348 349 attrs[0] = &val_dev_attr->attr; 350 attrs[1] = &pull_dev_attr->attr; 351 352 attr_group->attrs = attrs; 353 chip->attr_groups[i] = attr_group; 354 } 355 356 ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj, 357 chip->attr_groups); 358 if (ret) 359 return ret; 360 361 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 362 } 363 364 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 365 { 366 struct gpio_sim_chip *chip; 367 struct gpio_chip *gc; 368 const char *label; 369 u32 num_lines; 370 int ret; 371 372 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 373 if (ret) 374 return ret; 375 376 if (num_lines > GPIO_SIM_NGPIO_MAX) 377 return -ERANGE; 378 379 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 380 if (ret) { 381 label = devm_kasprintf(dev, GFP_KERNEL, "%s-%pfwP", 382 dev_name(dev), swnode); 383 if (!label) 384 return -ENOMEM; 385 } 386 387 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 388 if (!chip) 389 return -ENOMEM; 390 391 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 392 if (!chip->direction_map) 393 return -ENOMEM; 394 395 /* Default to input mode. */ 396 bitmap_fill(chip->direction_map, num_lines); 397 398 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 399 if (!chip->value_map) 400 return -ENOMEM; 401 402 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 403 if (!chip->pull_map) 404 return -ENOMEM; 405 406 chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines); 407 if (IS_ERR(chip->irq_sim)) 408 return PTR_ERR(chip->irq_sim); 409 410 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 411 if (ret) 412 return ret; 413 414 mutex_init(&chip->lock); 415 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy, 416 &chip->lock); 417 if (ret) 418 return ret; 419 420 gc = &chip->gc; 421 gc->base = -1; 422 gc->ngpio = num_lines; 423 gc->label = label; 424 gc->owner = THIS_MODULE; 425 gc->parent = dev; 426 gc->fwnode = swnode; 427 gc->get = gpio_sim_get; 428 gc->set = gpio_sim_set; 429 gc->get_multiple = gpio_sim_get_multiple; 430 gc->set_multiple = gpio_sim_set_multiple; 431 gc->direction_output = gpio_sim_direction_output; 432 gc->direction_input = gpio_sim_direction_input; 433 gc->get_direction = gpio_sim_get_direction; 434 gc->set_config = gpio_sim_set_config; 435 gc->to_irq = gpio_sim_to_irq; 436 gc->free = gpio_sim_free; 437 gc->can_sleep = true; 438 439 ret = devm_gpiochip_add_data(dev, gc, chip); 440 if (ret) 441 return ret; 442 443 /* Used by sysfs and configfs callbacks. */ 444 dev_set_drvdata(&gc->gpiodev->dev, chip); 445 446 return gpio_sim_setup_sysfs(chip); 447 } 448 449 static int gpio_sim_probe(struct platform_device *pdev) 450 { 451 struct device *dev = &pdev->dev; 452 struct fwnode_handle *swnode; 453 int ret; 454 455 device_for_each_child_node(dev, swnode) { 456 ret = gpio_sim_add_bank(swnode, dev); 457 if (ret) { 458 fwnode_handle_put(swnode); 459 return ret; 460 } 461 } 462 463 return 0; 464 } 465 466 static const struct of_device_id gpio_sim_of_match[] = { 467 { .compatible = "gpio-simulator" }, 468 { } 469 }; 470 MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 471 472 static struct platform_driver gpio_sim_driver = { 473 .driver = { 474 .name = "gpio-sim", 475 .of_match_table = gpio_sim_of_match, 476 }, 477 .probe = gpio_sim_probe, 478 }; 479 480 struct gpio_sim_device { 481 struct config_group group; 482 483 /* 484 * If pdev is NULL, the device is 'pending' (waiting for configuration). 485 * Once the pointer is assigned, the device has been created and the 486 * item is 'live'. 487 */ 488 struct platform_device *pdev; 489 int id; 490 491 /* 492 * Each configfs filesystem operation is protected with the subsystem 493 * mutex. Each separate attribute is protected with the buffer mutex. 494 * This structure however can be modified by callbacks of different 495 * attributes so we need another lock. 496 * 497 * We use this lock for protecting all data structures owned by this 498 * object too. 499 */ 500 struct mutex lock; 501 502 /* 503 * This is used to synchronously wait for the driver's probe to complete 504 * and notify the user-space about any errors. 505 */ 506 struct notifier_block bus_notifier; 507 struct completion probe_completion; 508 bool driver_bound; 509 510 struct gpiod_hog *hogs; 511 512 struct list_head bank_list; 513 }; 514 515 /* This is called with dev->lock already taken. */ 516 static int gpio_sim_bus_notifier_call(struct notifier_block *nb, 517 unsigned long action, void *data) 518 { 519 struct gpio_sim_device *simdev = container_of(nb, 520 struct gpio_sim_device, 521 bus_notifier); 522 struct device *dev = data; 523 char devname[32]; 524 525 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id); 526 527 if (strcmp(dev_name(dev), devname) == 0) { 528 if (action == BUS_NOTIFY_BOUND_DRIVER) 529 simdev->driver_bound = true; 530 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND) 531 simdev->driver_bound = false; 532 else 533 return NOTIFY_DONE; 534 535 complete(&simdev->probe_completion); 536 return NOTIFY_OK; 537 } 538 539 return NOTIFY_DONE; 540 } 541 542 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 543 { 544 struct config_group *group = to_config_group(item); 545 546 return container_of(group, struct gpio_sim_device, group); 547 } 548 549 struct gpio_sim_bank { 550 struct config_group group; 551 552 /* 553 * We could have used the ci_parent field of the config_item but 554 * configfs is stupid and calls the item's release callback after 555 * already having cleared the parent pointer even though the parent 556 * is guaranteed to survive the child... 557 * 558 * So we need to store the pointer to the parent struct here. We can 559 * dereference it anywhere we need with no checks and no locking as 560 * it's guaranteed to survive the children and protected by configfs 561 * locks. 562 * 563 * Same for other structures. 564 */ 565 struct gpio_sim_device *parent; 566 struct list_head siblings; 567 568 char *label; 569 unsigned int num_lines; 570 571 struct list_head line_list; 572 573 struct fwnode_handle *swnode; 574 }; 575 576 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 577 { 578 struct config_group *group = to_config_group(item); 579 580 return container_of(group, struct gpio_sim_bank, group); 581 } 582 583 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 584 { 585 return bank->label && *bank->label; 586 } 587 588 static struct gpio_sim_device * 589 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 590 { 591 return bank->parent; 592 } 593 594 struct gpio_sim_hog; 595 596 struct gpio_sim_line { 597 struct config_group group; 598 599 struct gpio_sim_bank *parent; 600 struct list_head siblings; 601 602 unsigned int offset; 603 char *name; 604 605 /* There can only be one hog per line. */ 606 struct gpio_sim_hog *hog; 607 }; 608 609 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 610 { 611 struct config_group *group = to_config_group(item); 612 613 return container_of(group, struct gpio_sim_line, group); 614 } 615 616 static struct gpio_sim_device * 617 gpio_sim_line_get_device(struct gpio_sim_line *line) 618 { 619 struct gpio_sim_bank *bank = line->parent; 620 621 return gpio_sim_bank_get_device(bank); 622 } 623 624 struct gpio_sim_hog { 625 struct config_item item; 626 struct gpio_sim_line *parent; 627 628 char *name; 629 int dir; 630 }; 631 632 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 633 { 634 return container_of(item, struct gpio_sim_hog, item); 635 } 636 637 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 638 { 639 struct gpio_sim_line *line = hog->parent; 640 641 return gpio_sim_line_get_device(line); 642 } 643 644 static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev) 645 { 646 return !!dev->pdev; 647 } 648 649 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 650 { 651 char *trimmed; 652 653 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 654 if (!trimmed) 655 return NULL; 656 657 return strim(trimmed); 658 } 659 660 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 661 char *page) 662 { 663 struct gpio_sim_device *dev = to_gpio_sim_device(item); 664 struct platform_device *pdev; 665 666 guard(mutex)(&dev->lock); 667 668 pdev = dev->pdev; 669 if (pdev) 670 return sprintf(page, "%s\n", dev_name(&pdev->dev)); 671 672 return sprintf(page, "gpio-sim.%d\n", dev->id); 673 } 674 675 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 676 677 static ssize_t 678 gpio_sim_device_config_live_show(struct config_item *item, char *page) 679 { 680 struct gpio_sim_device *dev = to_gpio_sim_device(item); 681 bool live; 682 683 scoped_guard(mutex, &dev->lock) 684 live = gpio_sim_device_is_live_unlocked(dev); 685 686 return sprintf(page, "%c\n", live ? '1' : '0'); 687 } 688 689 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank) 690 { 691 struct gpio_sim_line *line; 692 unsigned int size = 0; 693 694 list_for_each_entry(line, &bank->line_list, siblings) { 695 if (!line->name || (line->offset >= bank->num_lines)) 696 continue; 697 698 size = max(size, line->offset + 1); 699 } 700 701 return size; 702 } 703 704 static void 705 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 706 { 707 struct gpio_sim_line *line; 708 709 list_for_each_entry(line, &bank->line_list, siblings) { 710 if (!line->name || (line->offset >= bank->num_lines)) 711 continue; 712 713 line_names[line->offset] = line->name; 714 } 715 } 716 717 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 718 { 719 struct gpiod_hog *hog; 720 721 if (!dev->hogs) 722 return; 723 724 gpiod_remove_hogs(dev->hogs); 725 726 for (hog = dev->hogs; hog->chip_label; hog++) { 727 kfree(hog->chip_label); 728 kfree(hog->line_name); 729 } 730 731 kfree(dev->hogs); 732 dev->hogs = NULL; 733 } 734 735 static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 736 { 737 unsigned int num_hogs = 0, idx = 0; 738 struct gpio_sim_bank *bank; 739 struct gpio_sim_line *line; 740 struct gpiod_hog *hog; 741 742 list_for_each_entry(bank, &dev->bank_list, siblings) { 743 list_for_each_entry(line, &bank->line_list, siblings) { 744 if (line->offset >= bank->num_lines) 745 continue; 746 747 if (line->hog) 748 num_hogs++; 749 } 750 } 751 752 if (!num_hogs) 753 return 0; 754 755 /* Allocate one more for the sentinel. */ 756 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 757 if (!dev->hogs) 758 return -ENOMEM; 759 760 list_for_each_entry(bank, &dev->bank_list, siblings) { 761 list_for_each_entry(line, &bank->line_list, siblings) { 762 if (line->offset >= bank->num_lines) 763 continue; 764 765 if (!line->hog) 766 continue; 767 768 hog = &dev->hogs[idx++]; 769 770 /* 771 * We need to make this string manually because at this 772 * point the device doesn't exist yet and so dev_name() 773 * is not available. 774 */ 775 if (gpio_sim_bank_has_label(bank)) 776 hog->chip_label = kstrdup(bank->label, 777 GFP_KERNEL); 778 else 779 hog->chip_label = kasprintf(GFP_KERNEL, 780 "gpio-sim.%u-%pfwP", 781 dev->id, 782 bank->swnode); 783 if (!hog->chip_label) { 784 gpio_sim_remove_hogs(dev); 785 return -ENOMEM; 786 } 787 788 /* 789 * We need to duplicate this because the hog config 790 * item can be removed at any time (and we can't block 791 * it) and gpiolib doesn't make a deep copy of the hog 792 * data. 793 */ 794 if (line->hog->name) { 795 hog->line_name = kstrdup(line->hog->name, 796 GFP_KERNEL); 797 if (!hog->line_name) { 798 gpio_sim_remove_hogs(dev); 799 return -ENOMEM; 800 } 801 } 802 803 hog->chip_hwnum = line->offset; 804 hog->dflags = line->hog->dir; 805 } 806 } 807 808 gpiod_add_hogs(dev->hogs); 809 810 return 0; 811 } 812 813 static struct fwnode_handle * 814 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 815 struct fwnode_handle *parent) 816 { 817 struct property_entry properties[GPIO_SIM_PROP_MAX]; 818 unsigned int prop_idx = 0, line_names_size; 819 char **line_names __free(kfree) = NULL; 820 821 memset(properties, 0, sizeof(properties)); 822 823 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 824 825 if (gpio_sim_bank_has_label(bank)) 826 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 827 bank->label); 828 829 line_names_size = gpio_sim_get_line_names_size(bank); 830 if (line_names_size) { 831 line_names = kcalloc(line_names_size, sizeof(*line_names), 832 GFP_KERNEL); 833 if (!line_names) 834 return ERR_PTR(-ENOMEM); 835 836 gpio_sim_set_line_names(bank, line_names); 837 838 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 839 "gpio-line-names", 840 line_names, line_names_size); 841 } 842 843 return fwnode_create_software_node(properties, parent); 844 } 845 846 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 847 { 848 struct fwnode_handle *child; 849 850 fwnode_for_each_child_node(swnode, child) 851 fwnode_remove_software_node(child); 852 853 fwnode_remove_software_node(swnode); 854 } 855 856 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 857 { 858 struct gpio_sim_bank *this, *pos; 859 860 list_for_each_entry(this, &dev->bank_list, siblings) { 861 list_for_each_entry(pos, &dev->bank_list, siblings) { 862 if (this == pos || (!this->label || !pos->label)) 863 continue; 864 865 if (strcmp(this->label, pos->label) == 0) 866 return true; 867 } 868 } 869 870 return false; 871 } 872 873 static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev) 874 { 875 struct platform_device_info pdevinfo; 876 struct fwnode_handle *swnode; 877 struct platform_device *pdev; 878 struct gpio_sim_bank *bank; 879 int ret; 880 881 if (list_empty(&dev->bank_list)) 882 return -ENODATA; 883 884 /* 885 * Non-unique GPIO device labels are a corner-case we don't support 886 * as it would interfere with machine hogging mechanism and has little 887 * use in real life. 888 */ 889 if (gpio_sim_bank_labels_non_unique(dev)) 890 return -EINVAL; 891 892 memset(&pdevinfo, 0, sizeof(pdevinfo)); 893 894 swnode = fwnode_create_software_node(NULL, NULL); 895 if (IS_ERR(swnode)) 896 return PTR_ERR(swnode); 897 898 list_for_each_entry(bank, &dev->bank_list, siblings) { 899 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 900 if (IS_ERR(bank->swnode)) { 901 ret = PTR_ERR(bank->swnode); 902 gpio_sim_remove_swnode_recursive(swnode); 903 return ret; 904 } 905 } 906 907 ret = gpio_sim_add_hogs(dev); 908 if (ret) { 909 gpio_sim_remove_swnode_recursive(swnode); 910 return ret; 911 } 912 913 pdevinfo.name = "gpio-sim"; 914 pdevinfo.fwnode = swnode; 915 pdevinfo.id = dev->id; 916 917 reinit_completion(&dev->probe_completion); 918 dev->driver_bound = false; 919 bus_register_notifier(&platform_bus_type, &dev->bus_notifier); 920 921 pdev = platform_device_register_full(&pdevinfo); 922 if (IS_ERR(pdev)) { 923 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 924 gpio_sim_remove_hogs(dev); 925 gpio_sim_remove_swnode_recursive(swnode); 926 return PTR_ERR(pdev); 927 } 928 929 wait_for_completion(&dev->probe_completion); 930 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 931 932 if (!dev->driver_bound) { 933 /* Probe failed, check kernel log. */ 934 platform_device_unregister(pdev); 935 gpio_sim_remove_hogs(dev); 936 gpio_sim_remove_swnode_recursive(swnode); 937 return -ENXIO; 938 } 939 940 dev->pdev = pdev; 941 942 return 0; 943 } 944 945 static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev) 946 { 947 struct fwnode_handle *swnode; 948 949 swnode = dev_fwnode(&dev->pdev->dev); 950 platform_device_unregister(dev->pdev); 951 gpio_sim_remove_hogs(dev); 952 gpio_sim_remove_swnode_recursive(swnode); 953 dev->pdev = NULL; 954 } 955 956 static ssize_t 957 gpio_sim_device_config_live_store(struct config_item *item, 958 const char *page, size_t count) 959 { 960 struct gpio_sim_device *dev = to_gpio_sim_device(item); 961 bool live; 962 int ret; 963 964 ret = kstrtobool(page, &live); 965 if (ret) 966 return ret; 967 968 guard(mutex)(&dev->lock); 969 970 if (live == gpio_sim_device_is_live_unlocked(dev)) 971 ret = -EPERM; 972 else if (live) 973 ret = gpio_sim_device_activate_unlocked(dev); 974 else 975 gpio_sim_device_deactivate_unlocked(dev); 976 977 return ret ?: count; 978 } 979 980 CONFIGFS_ATTR(gpio_sim_device_config_, live); 981 982 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 983 &gpio_sim_device_config_attr_dev_name, 984 &gpio_sim_device_config_attr_live, 985 NULL 986 }; 987 988 struct gpio_sim_chip_name_ctx { 989 struct fwnode_handle *swnode; 990 char *page; 991 }; 992 993 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 994 { 995 struct gpio_sim_chip_name_ctx *ctx = data; 996 997 /* This would be the sysfs device exported in /sys/class/gpio. */ 998 if (dev->class) 999 return 0; 1000 1001 if (device_match_fwnode(dev, ctx->swnode)) 1002 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1003 1004 return 0; 1005 } 1006 1007 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1008 char *page) 1009 { 1010 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1011 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1012 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1013 1014 guard(mutex)(&dev->lock); 1015 1016 if (gpio_sim_device_is_live_unlocked(dev)) 1017 return device_for_each_child(&dev->pdev->dev, &ctx, 1018 gpio_sim_emit_chip_name); 1019 1020 return sprintf(page, "none\n"); 1021 } 1022 1023 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1024 1025 static ssize_t 1026 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1027 { 1028 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1029 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1030 1031 guard(mutex)(&dev->lock); 1032 1033 return sprintf(page, "%s\n", bank->label ?: ""); 1034 } 1035 1036 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1037 const char *page, size_t count) 1038 { 1039 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1040 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1041 char *trimmed; 1042 1043 guard(mutex)(&dev->lock); 1044 1045 if (gpio_sim_device_is_live_unlocked(dev)) 1046 return -EBUSY; 1047 1048 trimmed = gpio_sim_strdup_trimmed(page, count); 1049 if (!trimmed) 1050 return -ENOMEM; 1051 1052 kfree(bank->label); 1053 bank->label = trimmed; 1054 1055 return count; 1056 } 1057 1058 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1059 1060 static ssize_t 1061 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1062 { 1063 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1064 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1065 1066 guard(mutex)(&dev->lock); 1067 1068 return sprintf(page, "%u\n", bank->num_lines); 1069 } 1070 1071 static ssize_t 1072 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1073 const char *page, size_t count) 1074 { 1075 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1076 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1077 unsigned int num_lines; 1078 int ret; 1079 1080 ret = kstrtouint(page, 0, &num_lines); 1081 if (ret) 1082 return ret; 1083 1084 if (num_lines == 0) 1085 return -EINVAL; 1086 1087 guard(mutex)(&dev->lock); 1088 1089 if (gpio_sim_device_is_live_unlocked(dev)) 1090 return -EBUSY; 1091 1092 bank->num_lines = num_lines; 1093 1094 return count; 1095 } 1096 1097 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1098 1099 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1100 &gpio_sim_bank_config_attr_chip_name, 1101 &gpio_sim_bank_config_attr_label, 1102 &gpio_sim_bank_config_attr_num_lines, 1103 NULL 1104 }; 1105 1106 static ssize_t 1107 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1108 { 1109 struct gpio_sim_line *line = to_gpio_sim_line(item); 1110 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1111 1112 guard(mutex)(&dev->lock); 1113 1114 return sprintf(page, "%s\n", line->name ?: ""); 1115 } 1116 1117 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1118 const char *page, size_t count) 1119 { 1120 struct gpio_sim_line *line = to_gpio_sim_line(item); 1121 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1122 char *trimmed; 1123 1124 guard(mutex)(&dev->lock); 1125 1126 if (gpio_sim_device_is_live_unlocked(dev)) 1127 return -EBUSY; 1128 1129 trimmed = gpio_sim_strdup_trimmed(page, count); 1130 if (!trimmed) 1131 return -ENOMEM; 1132 1133 kfree(line->name); 1134 line->name = trimmed; 1135 1136 return count; 1137 } 1138 1139 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1140 1141 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1142 &gpio_sim_line_config_attr_name, 1143 NULL 1144 }; 1145 1146 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1147 char *page) 1148 { 1149 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1150 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1151 1152 guard(mutex)(&dev->lock); 1153 1154 return sprintf(page, "%s\n", hog->name ?: ""); 1155 } 1156 1157 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1158 const char *page, size_t count) 1159 { 1160 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1161 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1162 char *trimmed; 1163 1164 guard(mutex)(&dev->lock); 1165 1166 if (gpio_sim_device_is_live_unlocked(dev)) 1167 return -EBUSY; 1168 1169 trimmed = gpio_sim_strdup_trimmed(page, count); 1170 if (!trimmed) 1171 return -ENOMEM; 1172 1173 kfree(hog->name); 1174 hog->name = trimmed; 1175 1176 return count; 1177 } 1178 1179 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1180 1181 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1182 char *page) 1183 { 1184 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1185 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1186 char *repr; 1187 int dir; 1188 1189 scoped_guard(mutex, &dev->lock) 1190 dir = hog->dir; 1191 1192 switch (dir) { 1193 case GPIOD_IN: 1194 repr = "input"; 1195 break; 1196 case GPIOD_OUT_HIGH: 1197 repr = "output-high"; 1198 break; 1199 case GPIOD_OUT_LOW: 1200 repr = "output-low"; 1201 break; 1202 default: 1203 /* This would be a programmer bug. */ 1204 WARN(1, "Unexpected hog direction value: %d", dir); 1205 return -EINVAL; 1206 } 1207 1208 return sprintf(page, "%s\n", repr); 1209 } 1210 1211 static ssize_t 1212 gpio_sim_hog_config_direction_store(struct config_item *item, 1213 const char *page, size_t count) 1214 { 1215 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1216 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1217 int dir; 1218 1219 guard(mutex)(&dev->lock); 1220 1221 if (gpio_sim_device_is_live_unlocked(dev)) 1222 return -EBUSY; 1223 1224 if (sysfs_streq(page, "input")) 1225 dir = GPIOD_IN; 1226 else if (sysfs_streq(page, "output-high")) 1227 dir = GPIOD_OUT_HIGH; 1228 else if (sysfs_streq(page, "output-low")) 1229 dir = GPIOD_OUT_LOW; 1230 else 1231 return -EINVAL; 1232 1233 hog->dir = dir; 1234 1235 return count; 1236 } 1237 1238 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1239 1240 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1241 &gpio_sim_hog_config_attr_name, 1242 &gpio_sim_hog_config_attr_direction, 1243 NULL 1244 }; 1245 1246 static void gpio_sim_hog_config_item_release(struct config_item *item) 1247 { 1248 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1249 struct gpio_sim_line *line = hog->parent; 1250 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1251 1252 scoped_guard(mutex, &dev->lock) 1253 line->hog = NULL; 1254 1255 kfree(hog->name); 1256 kfree(hog); 1257 } 1258 1259 static struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1260 .release = gpio_sim_hog_config_item_release, 1261 }; 1262 1263 static const struct config_item_type gpio_sim_hog_config_type = { 1264 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1265 .ct_attrs = gpio_sim_hog_config_attrs, 1266 .ct_owner = THIS_MODULE, 1267 }; 1268 1269 static struct config_item * 1270 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1271 { 1272 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1273 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1274 struct gpio_sim_hog *hog; 1275 1276 if (strcmp(name, "hog") != 0) 1277 return ERR_PTR(-EINVAL); 1278 1279 guard(mutex)(&dev->lock); 1280 1281 hog = kzalloc(sizeof(*hog), GFP_KERNEL); 1282 if (!hog) 1283 return ERR_PTR(-ENOMEM); 1284 1285 config_item_init_type_name(&hog->item, name, 1286 &gpio_sim_hog_config_type); 1287 1288 hog->dir = GPIOD_IN; 1289 hog->name = NULL; 1290 hog->parent = line; 1291 line->hog = hog; 1292 1293 return &hog->item; 1294 } 1295 1296 static void gpio_sim_line_config_group_release(struct config_item *item) 1297 { 1298 struct gpio_sim_line *line = to_gpio_sim_line(item); 1299 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1300 1301 scoped_guard(mutex, &dev->lock) 1302 list_del(&line->siblings); 1303 1304 kfree(line->name); 1305 kfree(line); 1306 } 1307 1308 static struct configfs_item_operations gpio_sim_line_config_item_ops = { 1309 .release = gpio_sim_line_config_group_release, 1310 }; 1311 1312 static struct configfs_group_operations gpio_sim_line_config_group_ops = { 1313 .make_item = gpio_sim_line_config_make_hog_item, 1314 }; 1315 1316 static const struct config_item_type gpio_sim_line_config_type = { 1317 .ct_item_ops = &gpio_sim_line_config_item_ops, 1318 .ct_group_ops = &gpio_sim_line_config_group_ops, 1319 .ct_attrs = gpio_sim_line_config_attrs, 1320 .ct_owner = THIS_MODULE, 1321 }; 1322 1323 static struct config_group * 1324 gpio_sim_bank_config_make_line_group(struct config_group *group, 1325 const char *name) 1326 { 1327 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1328 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1329 struct gpio_sim_line *line; 1330 unsigned int offset; 1331 int ret, nchar; 1332 1333 ret = sscanf(name, "line%u%n", &offset, &nchar); 1334 if (ret != 1 || nchar != strlen(name)) 1335 return ERR_PTR(-EINVAL); 1336 1337 guard(mutex)(&dev->lock); 1338 1339 if (gpio_sim_device_is_live_unlocked(dev)) 1340 return ERR_PTR(-EBUSY); 1341 1342 line = kzalloc(sizeof(*line), GFP_KERNEL); 1343 if (!line) 1344 return ERR_PTR(-ENOMEM); 1345 1346 config_group_init_type_name(&line->group, name, 1347 &gpio_sim_line_config_type); 1348 1349 line->parent = bank; 1350 line->offset = offset; 1351 list_add_tail(&line->siblings, &bank->line_list); 1352 1353 return &line->group; 1354 } 1355 1356 static void gpio_sim_bank_config_group_release(struct config_item *item) 1357 { 1358 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1359 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1360 1361 scoped_guard(mutex, &dev->lock) 1362 list_del(&bank->siblings); 1363 1364 kfree(bank->label); 1365 kfree(bank); 1366 } 1367 1368 static struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1369 .release = gpio_sim_bank_config_group_release, 1370 }; 1371 1372 static struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1373 .make_group = gpio_sim_bank_config_make_line_group, 1374 }; 1375 1376 static const struct config_item_type gpio_sim_bank_config_group_type = { 1377 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1378 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1379 .ct_attrs = gpio_sim_bank_config_attrs, 1380 .ct_owner = THIS_MODULE, 1381 }; 1382 1383 static struct config_group * 1384 gpio_sim_device_config_make_bank_group(struct config_group *group, 1385 const char *name) 1386 { 1387 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1388 struct gpio_sim_bank *bank; 1389 1390 guard(mutex)(&dev->lock); 1391 1392 if (gpio_sim_device_is_live_unlocked(dev)) 1393 return ERR_PTR(-EBUSY); 1394 1395 bank = kzalloc(sizeof(*bank), GFP_KERNEL); 1396 if (!bank) 1397 return ERR_PTR(-ENOMEM); 1398 1399 config_group_init_type_name(&bank->group, name, 1400 &gpio_sim_bank_config_group_type); 1401 bank->num_lines = 1; 1402 bank->parent = dev; 1403 INIT_LIST_HEAD(&bank->line_list); 1404 list_add_tail(&bank->siblings, &dev->bank_list); 1405 1406 return &bank->group; 1407 } 1408 1409 static void gpio_sim_device_config_group_release(struct config_item *item) 1410 { 1411 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1412 1413 scoped_guard(mutex, &dev->lock) { 1414 if (gpio_sim_device_is_live_unlocked(dev)) 1415 gpio_sim_device_deactivate_unlocked(dev); 1416 } 1417 1418 mutex_destroy(&dev->lock); 1419 ida_free(&gpio_sim_ida, dev->id); 1420 kfree(dev); 1421 } 1422 1423 static struct configfs_item_operations gpio_sim_device_config_item_ops = { 1424 .release = gpio_sim_device_config_group_release, 1425 }; 1426 1427 static struct configfs_group_operations gpio_sim_device_config_group_ops = { 1428 .make_group = gpio_sim_device_config_make_bank_group, 1429 }; 1430 1431 static const struct config_item_type gpio_sim_device_config_group_type = { 1432 .ct_item_ops = &gpio_sim_device_config_item_ops, 1433 .ct_group_ops = &gpio_sim_device_config_group_ops, 1434 .ct_attrs = gpio_sim_device_config_attrs, 1435 .ct_owner = THIS_MODULE, 1436 }; 1437 1438 static struct config_group * 1439 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1440 { 1441 struct gpio_sim_device *dev __free(kfree) = NULL; 1442 int id; 1443 1444 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1445 if (!dev) 1446 return ERR_PTR(-ENOMEM); 1447 1448 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1449 if (id < 0) 1450 return ERR_PTR(id); 1451 1452 config_group_init_type_name(&dev->group, name, 1453 &gpio_sim_device_config_group_type); 1454 dev->id = id; 1455 mutex_init(&dev->lock); 1456 INIT_LIST_HEAD(&dev->bank_list); 1457 1458 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call; 1459 init_completion(&dev->probe_completion); 1460 1461 return &no_free_ptr(dev)->group; 1462 } 1463 1464 static struct configfs_group_operations gpio_sim_config_group_ops = { 1465 .make_group = gpio_sim_config_make_device_group, 1466 }; 1467 1468 static const struct config_item_type gpio_sim_config_type = { 1469 .ct_group_ops = &gpio_sim_config_group_ops, 1470 .ct_owner = THIS_MODULE, 1471 }; 1472 1473 static struct configfs_subsystem gpio_sim_config_subsys = { 1474 .su_group = { 1475 .cg_item = { 1476 .ci_namebuf = "gpio-sim", 1477 .ci_type = &gpio_sim_config_type, 1478 }, 1479 }, 1480 }; 1481 1482 static int __init gpio_sim_init(void) 1483 { 1484 int ret; 1485 1486 ret = platform_driver_register(&gpio_sim_driver); 1487 if (ret) { 1488 pr_err("Error %d while registering the platform driver\n", ret); 1489 return ret; 1490 } 1491 1492 config_group_init(&gpio_sim_config_subsys.su_group); 1493 mutex_init(&gpio_sim_config_subsys.su_mutex); 1494 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1495 if (ret) { 1496 pr_err("Error %d while registering the configfs subsystem %s\n", 1497 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1498 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1499 platform_driver_unregister(&gpio_sim_driver); 1500 return ret; 1501 } 1502 1503 return 0; 1504 } 1505 module_init(gpio_sim_init); 1506 1507 static void __exit gpio_sim_exit(void) 1508 { 1509 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1510 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1511 platform_driver_unregister(&gpio_sim_driver); 1512 } 1513 module_exit(gpio_sim_exit); 1514 1515 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl"); 1516 MODULE_DESCRIPTION("GPIO Simulator Module"); 1517 MODULE_LICENSE("GPL"); 1518