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/err.h> 16 #include <linux/gpio/consumer.h> 17 #include <linux/gpio/driver.h> 18 #include <linux/gpio/machine.h> 19 #include <linux/idr.h> 20 #include <linux/interrupt.h> 21 #include <linux/irq.h> 22 #include <linux/irq_sim.h> 23 #include <linux/list.h> 24 #include <linux/minmax.h> 25 #include <linux/mod_devicetable.h> 26 #include <linux/module.h> 27 #include <linux/mutex.h> 28 #include <linux/notifier.h> 29 #include <linux/platform_device.h> 30 #include <linux/property.h> 31 #include <linux/slab.h> 32 #include <linux/string.h> 33 #include <linux/string_helpers.h> 34 #include <linux/sysfs.h> 35 #include <linux/types.h> 36 37 #define GPIO_SIM_NGPIO_MAX 1024 38 #define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */ 39 #define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */ 40 41 static DEFINE_IDA(gpio_sim_ida); 42 43 struct gpio_sim_chip { 44 struct gpio_chip gc; 45 struct device *dev; 46 unsigned long *request_map; 47 unsigned long *direction_map; 48 unsigned long *value_map; 49 unsigned long *pull_map; 50 struct irq_domain *irq_sim; 51 struct mutex lock; 52 const struct attribute_group **attr_groups; 53 }; 54 55 struct gpio_sim_attribute { 56 struct device_attribute dev_attr; 57 unsigned int offset; 58 }; 59 60 static struct gpio_sim_attribute * 61 to_gpio_sim_attr(struct device_attribute *dev_attr) 62 { 63 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 64 } 65 66 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 67 unsigned int offset, int value) 68 { 69 int irq, irq_type, ret; 70 71 guard(mutex)(&chip->lock); 72 73 if (test_bit(offset, chip->request_map) && 74 test_bit(offset, chip->direction_map)) { 75 if (value == !!test_bit(offset, chip->value_map)) 76 goto set_pull; 77 78 /* 79 * This is fine - it just means, nobody is listening 80 * for interrupts on this line, otherwise 81 * irq_create_mapping() would have been called from 82 * the to_irq() callback. 83 */ 84 irq = irq_find_mapping(chip->irq_sim, offset); 85 if (!irq) 86 goto set_value; 87 88 irq_type = irq_get_trigger_type(irq); 89 90 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) || 91 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) { 92 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 93 true); 94 if (ret) 95 goto set_pull; 96 } 97 } 98 99 set_value: 100 /* Change the value unless we're actively driving the line. */ 101 if (!test_bit(offset, chip->request_map) || 102 test_bit(offset, chip->direction_map)) 103 __assign_bit(offset, chip->value_map, value); 104 105 set_pull: 106 __assign_bit(offset, chip->pull_map, value); 107 return 0; 108 } 109 110 static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset) 111 { 112 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 113 114 guard(mutex)(&chip->lock); 115 116 return !!test_bit(offset, chip->value_map); 117 } 118 119 static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value) 120 { 121 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 122 123 scoped_guard(mutex, &chip->lock) 124 __assign_bit(offset, chip->value_map, value); 125 } 126 127 static int gpio_sim_get_multiple(struct gpio_chip *gc, 128 unsigned long *mask, unsigned long *bits) 129 { 130 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 131 132 scoped_guard(mutex, &chip->lock) 133 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 134 135 return 0; 136 } 137 138 static void gpio_sim_set_multiple(struct gpio_chip *gc, 139 unsigned long *mask, unsigned long *bits) 140 { 141 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 142 143 scoped_guard(mutex, &chip->lock) 144 bitmap_replace(chip->value_map, chip->value_map, bits, mask, 145 gc->ngpio); 146 } 147 148 static int gpio_sim_direction_output(struct gpio_chip *gc, 149 unsigned int offset, int value) 150 { 151 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 152 153 scoped_guard(mutex, &chip->lock) { 154 __clear_bit(offset, chip->direction_map); 155 __assign_bit(offset, chip->value_map, value); 156 } 157 158 return 0; 159 } 160 161 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 162 { 163 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 164 165 scoped_guard(mutex, &chip->lock) 166 __set_bit(offset, chip->direction_map); 167 168 return 0; 169 } 170 171 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 172 { 173 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 174 int direction; 175 176 scoped_guard(mutex, &chip->lock) 177 direction = !!test_bit(offset, chip->direction_map); 178 179 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; 180 } 181 182 static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset, 183 unsigned long config) 184 { 185 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 186 187 switch (pinconf_to_config_param(config)) { 188 case PIN_CONFIG_BIAS_PULL_UP: 189 return gpio_sim_apply_pull(chip, offset, 1); 190 case PIN_CONFIG_BIAS_PULL_DOWN: 191 return gpio_sim_apply_pull(chip, offset, 0); 192 default: 193 break; 194 } 195 196 return -ENOTSUPP; 197 } 198 199 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 200 { 201 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 202 203 return irq_create_mapping(chip->irq_sim, offset); 204 } 205 206 static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset) 207 { 208 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 209 210 scoped_guard(mutex, &chip->lock) 211 __set_bit(offset, chip->request_map); 212 213 return 0; 214 } 215 216 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 217 { 218 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 219 220 scoped_guard(mutex, &chip->lock) { 221 __assign_bit(offset, chip->value_map, 222 !!test_bit(offset, chip->pull_map)); 223 __clear_bit(offset, chip->request_map); 224 } 225 } 226 227 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 228 struct device_attribute *attr, char *buf) 229 { 230 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 231 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 232 int val; 233 234 scoped_guard(mutex, &chip->lock) 235 val = !!test_bit(line_attr->offset, chip->value_map); 236 237 return sysfs_emit(buf, "%d\n", val); 238 } 239 240 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 241 struct device_attribute *attr, 242 const char *buf, size_t count) 243 { 244 /* 245 * Not assigning this function will result in write() returning -EIO 246 * which is confusing. Return -EPERM explicitly. 247 */ 248 return -EPERM; 249 } 250 251 static const char *const gpio_sim_sysfs_pull_strings[] = { 252 [0] = "pull-down", 253 [1] = "pull-up", 254 }; 255 256 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 257 struct device_attribute *attr, 258 char *buf) 259 { 260 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 261 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 262 int pull; 263 264 scoped_guard(mutex, &chip->lock) 265 pull = !!test_bit(line_attr->offset, chip->pull_map); 266 267 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 268 } 269 270 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 271 struct device_attribute *attr, 272 const char *buf, size_t len) 273 { 274 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 275 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 276 int ret, pull; 277 278 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 279 if (pull < 0) 280 return pull; 281 282 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 283 if (ret) 284 return ret; 285 286 return len; 287 } 288 289 static void gpio_sim_mutex_destroy(void *data) 290 { 291 struct mutex *lock = data; 292 293 mutex_destroy(lock); 294 } 295 296 static void gpio_sim_put_device(void *data) 297 { 298 struct device *dev = data; 299 300 put_device(dev); 301 } 302 303 static void gpio_sim_dispose_mappings(void *data) 304 { 305 struct gpio_sim_chip *chip = data; 306 unsigned int i; 307 308 for (i = 0; i < chip->gc.ngpio; i++) 309 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 310 } 311 312 static void gpio_sim_sysfs_remove(void *data) 313 { 314 struct gpio_sim_chip *chip = data; 315 316 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups); 317 } 318 319 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 320 { 321 struct device_attribute *val_dev_attr, *pull_dev_attr; 322 struct gpio_sim_attribute *val_attr, *pull_attr; 323 unsigned int num_lines = chip->gc.ngpio; 324 struct device *dev = chip->gc.parent; 325 struct attribute_group *attr_group; 326 struct attribute **attrs; 327 int i, ret; 328 329 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 330 num_lines + 1, GFP_KERNEL); 331 if (!chip->attr_groups) 332 return -ENOMEM; 333 334 for (i = 0; i < num_lines; i++) { 335 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 336 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 337 GFP_KERNEL); 338 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 339 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 340 if (!attr_group || !attrs || !val_attr || !pull_attr) 341 return -ENOMEM; 342 343 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 344 "sim_gpio%u", i); 345 if (!attr_group->name) 346 return -ENOMEM; 347 348 val_attr->offset = pull_attr->offset = i; 349 350 val_dev_attr = &val_attr->dev_attr; 351 pull_dev_attr = &pull_attr->dev_attr; 352 353 sysfs_attr_init(&val_dev_attr->attr); 354 sysfs_attr_init(&pull_dev_attr->attr); 355 356 val_dev_attr->attr.name = "value"; 357 pull_dev_attr->attr.name = "pull"; 358 359 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 360 361 val_dev_attr->show = gpio_sim_sysfs_val_show; 362 val_dev_attr->store = gpio_sim_sysfs_val_store; 363 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 364 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 365 366 attrs[0] = &val_dev_attr->attr; 367 attrs[1] = &pull_dev_attr->attr; 368 369 attr_group->attrs = attrs; 370 chip->attr_groups[i] = attr_group; 371 } 372 373 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups); 374 if (ret) 375 return ret; 376 377 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 378 } 379 380 static int gpio_sim_dev_match_fwnode(struct device *dev, void *data) 381 { 382 return device_match_fwnode(dev, data); 383 } 384 385 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 386 { 387 struct gpio_sim_chip *chip; 388 struct gpio_chip *gc; 389 const char *label; 390 u32 num_lines; 391 int ret; 392 393 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 394 if (ret) 395 return ret; 396 397 if (num_lines > GPIO_SIM_NGPIO_MAX) 398 return -ERANGE; 399 400 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 401 if (ret) { 402 label = devm_kasprintf(dev, GFP_KERNEL, "%s-%pfwP", 403 dev_name(dev), swnode); 404 if (!label) 405 return -ENOMEM; 406 } 407 408 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 409 if (!chip) 410 return -ENOMEM; 411 412 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 413 if (!chip->request_map) 414 return -ENOMEM; 415 416 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 417 if (!chip->direction_map) 418 return -ENOMEM; 419 420 /* Default to input mode. */ 421 bitmap_fill(chip->direction_map, num_lines); 422 423 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 424 if (!chip->value_map) 425 return -ENOMEM; 426 427 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 428 if (!chip->pull_map) 429 return -ENOMEM; 430 431 chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines); 432 if (IS_ERR(chip->irq_sim)) 433 return PTR_ERR(chip->irq_sim); 434 435 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 436 if (ret) 437 return ret; 438 439 mutex_init(&chip->lock); 440 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy, 441 &chip->lock); 442 if (ret) 443 return ret; 444 445 gc = &chip->gc; 446 gc->base = -1; 447 gc->ngpio = num_lines; 448 gc->label = label; 449 gc->owner = THIS_MODULE; 450 gc->parent = dev; 451 gc->fwnode = swnode; 452 gc->get = gpio_sim_get; 453 gc->set = gpio_sim_set; 454 gc->get_multiple = gpio_sim_get_multiple; 455 gc->set_multiple = gpio_sim_set_multiple; 456 gc->direction_output = gpio_sim_direction_output; 457 gc->direction_input = gpio_sim_direction_input; 458 gc->get_direction = gpio_sim_get_direction; 459 gc->set_config = gpio_sim_set_config; 460 gc->to_irq = gpio_sim_to_irq; 461 gc->request = gpio_sim_request; 462 gc->free = gpio_sim_free; 463 gc->can_sleep = true; 464 465 ret = devm_gpiochip_add_data(dev, gc, chip); 466 if (ret) 467 return ret; 468 469 chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode); 470 if (!chip->dev) 471 return -ENODEV; 472 473 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev); 474 if (ret) 475 return ret; 476 477 /* Used by sysfs callbacks. */ 478 dev_set_drvdata(chip->dev, chip); 479 480 return gpio_sim_setup_sysfs(chip); 481 } 482 483 static int gpio_sim_probe(struct platform_device *pdev) 484 { 485 struct device *dev = &pdev->dev; 486 struct fwnode_handle *swnode; 487 int ret; 488 489 device_for_each_child_node(dev, swnode) { 490 ret = gpio_sim_add_bank(swnode, dev); 491 if (ret) { 492 fwnode_handle_put(swnode); 493 return ret; 494 } 495 } 496 497 return 0; 498 } 499 500 static const struct of_device_id gpio_sim_of_match[] = { 501 { .compatible = "gpio-simulator" }, 502 { } 503 }; 504 MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 505 506 static struct platform_driver gpio_sim_driver = { 507 .driver = { 508 .name = "gpio-sim", 509 .of_match_table = gpio_sim_of_match, 510 }, 511 .probe = gpio_sim_probe, 512 }; 513 514 struct gpio_sim_device { 515 struct config_group group; 516 517 /* 518 * If pdev is NULL, the device is 'pending' (waiting for configuration). 519 * Once the pointer is assigned, the device has been created and the 520 * item is 'live'. 521 */ 522 struct platform_device *pdev; 523 int id; 524 525 /* 526 * Each configfs filesystem operation is protected with the subsystem 527 * mutex. Each separate attribute is protected with the buffer mutex. 528 * This structure however can be modified by callbacks of different 529 * attributes so we need another lock. 530 * 531 * We use this lock for protecting all data structures owned by this 532 * object too. 533 */ 534 struct mutex lock; 535 536 /* 537 * This is used to synchronously wait for the driver's probe to complete 538 * and notify the user-space about any errors. 539 */ 540 struct notifier_block bus_notifier; 541 struct completion probe_completion; 542 bool driver_bound; 543 544 struct gpiod_hog *hogs; 545 546 struct list_head bank_list; 547 }; 548 549 /* This is called with dev->lock already taken. */ 550 static int gpio_sim_bus_notifier_call(struct notifier_block *nb, 551 unsigned long action, void *data) 552 { 553 struct gpio_sim_device *simdev = container_of(nb, 554 struct gpio_sim_device, 555 bus_notifier); 556 struct device *dev = data; 557 char devname[32]; 558 559 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id); 560 561 if (strcmp(dev_name(dev), devname) == 0) { 562 if (action == BUS_NOTIFY_BOUND_DRIVER) 563 simdev->driver_bound = true; 564 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND) 565 simdev->driver_bound = false; 566 else 567 return NOTIFY_DONE; 568 569 complete(&simdev->probe_completion); 570 return NOTIFY_OK; 571 } 572 573 return NOTIFY_DONE; 574 } 575 576 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 577 { 578 struct config_group *group = to_config_group(item); 579 580 return container_of(group, struct gpio_sim_device, group); 581 } 582 583 struct gpio_sim_bank { 584 struct config_group group; 585 586 /* 587 * We could have used the ci_parent field of the config_item but 588 * configfs is stupid and calls the item's release callback after 589 * already having cleared the parent pointer even though the parent 590 * is guaranteed to survive the child... 591 * 592 * So we need to store the pointer to the parent struct here. We can 593 * dereference it anywhere we need with no checks and no locking as 594 * it's guaranteed to survive the children and protected by configfs 595 * locks. 596 * 597 * Same for other structures. 598 */ 599 struct gpio_sim_device *parent; 600 struct list_head siblings; 601 602 char *label; 603 unsigned int num_lines; 604 605 struct list_head line_list; 606 607 struct fwnode_handle *swnode; 608 }; 609 610 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 611 { 612 struct config_group *group = to_config_group(item); 613 614 return container_of(group, struct gpio_sim_bank, group); 615 } 616 617 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 618 { 619 return bank->label && *bank->label; 620 } 621 622 static struct gpio_sim_device * 623 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 624 { 625 return bank->parent; 626 } 627 628 struct gpio_sim_hog; 629 630 struct gpio_sim_line { 631 struct config_group group; 632 633 struct gpio_sim_bank *parent; 634 struct list_head siblings; 635 636 unsigned int offset; 637 char *name; 638 639 /* There can only be one hog per line. */ 640 struct gpio_sim_hog *hog; 641 }; 642 643 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 644 { 645 struct config_group *group = to_config_group(item); 646 647 return container_of(group, struct gpio_sim_line, group); 648 } 649 650 static struct gpio_sim_device * 651 gpio_sim_line_get_device(struct gpio_sim_line *line) 652 { 653 struct gpio_sim_bank *bank = line->parent; 654 655 return gpio_sim_bank_get_device(bank); 656 } 657 658 struct gpio_sim_hog { 659 struct config_item item; 660 struct gpio_sim_line *parent; 661 662 char *name; 663 int dir; 664 }; 665 666 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 667 { 668 return container_of(item, struct gpio_sim_hog, item); 669 } 670 671 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 672 { 673 struct gpio_sim_line *line = hog->parent; 674 675 return gpio_sim_line_get_device(line); 676 } 677 678 static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev) 679 { 680 return !!dev->pdev; 681 } 682 683 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 684 { 685 char *trimmed; 686 687 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 688 if (!trimmed) 689 return NULL; 690 691 return strim(trimmed); 692 } 693 694 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 695 char *page) 696 { 697 struct gpio_sim_device *dev = to_gpio_sim_device(item); 698 struct platform_device *pdev; 699 700 guard(mutex)(&dev->lock); 701 702 pdev = dev->pdev; 703 if (pdev) 704 return sprintf(page, "%s\n", dev_name(&pdev->dev)); 705 706 return sprintf(page, "gpio-sim.%d\n", dev->id); 707 } 708 709 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 710 711 static ssize_t 712 gpio_sim_device_config_live_show(struct config_item *item, char *page) 713 { 714 struct gpio_sim_device *dev = to_gpio_sim_device(item); 715 bool live; 716 717 scoped_guard(mutex, &dev->lock) 718 live = gpio_sim_device_is_live_unlocked(dev); 719 720 return sprintf(page, "%c\n", live ? '1' : '0'); 721 } 722 723 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank) 724 { 725 struct gpio_sim_line *line; 726 unsigned int size = 0; 727 728 list_for_each_entry(line, &bank->line_list, siblings) { 729 if (!line->name || (line->offset >= bank->num_lines)) 730 continue; 731 732 size = max(size, line->offset + 1); 733 } 734 735 return size; 736 } 737 738 static void 739 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 740 { 741 struct gpio_sim_line *line; 742 743 list_for_each_entry(line, &bank->line_list, siblings) { 744 if (!line->name || (line->offset >= bank->num_lines)) 745 continue; 746 747 line_names[line->offset] = line->name; 748 } 749 } 750 751 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 752 { 753 struct gpiod_hog *hog; 754 755 if (!dev->hogs) 756 return; 757 758 gpiod_remove_hogs(dev->hogs); 759 760 for (hog = dev->hogs; hog->chip_label; hog++) { 761 kfree(hog->chip_label); 762 kfree(hog->line_name); 763 } 764 765 kfree(dev->hogs); 766 dev->hogs = NULL; 767 } 768 769 static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 770 { 771 unsigned int num_hogs = 0, idx = 0; 772 struct gpio_sim_bank *bank; 773 struct gpio_sim_line *line; 774 struct gpiod_hog *hog; 775 776 list_for_each_entry(bank, &dev->bank_list, siblings) { 777 list_for_each_entry(line, &bank->line_list, siblings) { 778 if (line->offset >= bank->num_lines) 779 continue; 780 781 if (line->hog) 782 num_hogs++; 783 } 784 } 785 786 if (!num_hogs) 787 return 0; 788 789 /* Allocate one more for the sentinel. */ 790 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 791 if (!dev->hogs) 792 return -ENOMEM; 793 794 list_for_each_entry(bank, &dev->bank_list, siblings) { 795 list_for_each_entry(line, &bank->line_list, siblings) { 796 if (line->offset >= bank->num_lines) 797 continue; 798 799 if (!line->hog) 800 continue; 801 802 hog = &dev->hogs[idx++]; 803 804 /* 805 * We need to make this string manually because at this 806 * point the device doesn't exist yet and so dev_name() 807 * is not available. 808 */ 809 if (gpio_sim_bank_has_label(bank)) 810 hog->chip_label = kstrdup(bank->label, 811 GFP_KERNEL); 812 else 813 hog->chip_label = kasprintf(GFP_KERNEL, 814 "gpio-sim.%u-%pfwP", 815 dev->id, 816 bank->swnode); 817 if (!hog->chip_label) { 818 gpio_sim_remove_hogs(dev); 819 return -ENOMEM; 820 } 821 822 /* 823 * We need to duplicate this because the hog config 824 * item can be removed at any time (and we can't block 825 * it) and gpiolib doesn't make a deep copy of the hog 826 * data. 827 */ 828 if (line->hog->name) { 829 hog->line_name = kstrdup(line->hog->name, 830 GFP_KERNEL); 831 if (!hog->line_name) { 832 gpio_sim_remove_hogs(dev); 833 return -ENOMEM; 834 } 835 } 836 837 hog->chip_hwnum = line->offset; 838 hog->dflags = line->hog->dir; 839 } 840 } 841 842 gpiod_add_hogs(dev->hogs); 843 844 return 0; 845 } 846 847 static struct fwnode_handle * 848 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 849 struct fwnode_handle *parent) 850 { 851 struct property_entry properties[GPIO_SIM_PROP_MAX]; 852 unsigned int prop_idx = 0, line_names_size; 853 char **line_names __free(kfree) = NULL; 854 855 memset(properties, 0, sizeof(properties)); 856 857 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 858 859 if (gpio_sim_bank_has_label(bank)) 860 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 861 bank->label); 862 863 line_names_size = gpio_sim_get_line_names_size(bank); 864 if (line_names_size) { 865 line_names = kcalloc(line_names_size, sizeof(*line_names), 866 GFP_KERNEL); 867 if (!line_names) 868 return ERR_PTR(-ENOMEM); 869 870 gpio_sim_set_line_names(bank, line_names); 871 872 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 873 "gpio-line-names", 874 line_names, line_names_size); 875 } 876 877 return fwnode_create_software_node(properties, parent); 878 } 879 880 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 881 { 882 struct fwnode_handle *child; 883 884 fwnode_for_each_child_node(swnode, child) 885 fwnode_remove_software_node(child); 886 887 fwnode_remove_software_node(swnode); 888 } 889 890 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 891 { 892 struct gpio_sim_bank *this, *pos; 893 894 list_for_each_entry(this, &dev->bank_list, siblings) { 895 list_for_each_entry(pos, &dev->bank_list, siblings) { 896 if (this == pos || (!this->label || !pos->label)) 897 continue; 898 899 if (strcmp(this->label, pos->label) == 0) 900 return true; 901 } 902 } 903 904 return false; 905 } 906 907 static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev) 908 { 909 struct platform_device_info pdevinfo; 910 struct fwnode_handle *swnode; 911 struct platform_device *pdev; 912 struct gpio_sim_bank *bank; 913 int ret; 914 915 if (list_empty(&dev->bank_list)) 916 return -ENODATA; 917 918 /* 919 * Non-unique GPIO device labels are a corner-case we don't support 920 * as it would interfere with machine hogging mechanism and has little 921 * use in real life. 922 */ 923 if (gpio_sim_bank_labels_non_unique(dev)) 924 return -EINVAL; 925 926 memset(&pdevinfo, 0, sizeof(pdevinfo)); 927 928 swnode = fwnode_create_software_node(NULL, NULL); 929 if (IS_ERR(swnode)) 930 return PTR_ERR(swnode); 931 932 list_for_each_entry(bank, &dev->bank_list, siblings) { 933 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 934 if (IS_ERR(bank->swnode)) { 935 ret = PTR_ERR(bank->swnode); 936 gpio_sim_remove_swnode_recursive(swnode); 937 return ret; 938 } 939 } 940 941 ret = gpio_sim_add_hogs(dev); 942 if (ret) { 943 gpio_sim_remove_swnode_recursive(swnode); 944 return ret; 945 } 946 947 pdevinfo.name = "gpio-sim"; 948 pdevinfo.fwnode = swnode; 949 pdevinfo.id = dev->id; 950 951 reinit_completion(&dev->probe_completion); 952 dev->driver_bound = false; 953 bus_register_notifier(&platform_bus_type, &dev->bus_notifier); 954 955 pdev = platform_device_register_full(&pdevinfo); 956 if (IS_ERR(pdev)) { 957 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 958 gpio_sim_remove_hogs(dev); 959 gpio_sim_remove_swnode_recursive(swnode); 960 return PTR_ERR(pdev); 961 } 962 963 wait_for_completion(&dev->probe_completion); 964 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 965 966 if (!dev->driver_bound) { 967 /* Probe failed, check kernel log. */ 968 platform_device_unregister(pdev); 969 gpio_sim_remove_hogs(dev); 970 gpio_sim_remove_swnode_recursive(swnode); 971 return -ENXIO; 972 } 973 974 dev->pdev = pdev; 975 976 return 0; 977 } 978 979 static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev) 980 { 981 struct fwnode_handle *swnode; 982 983 swnode = dev_fwnode(&dev->pdev->dev); 984 platform_device_unregister(dev->pdev); 985 gpio_sim_remove_hogs(dev); 986 gpio_sim_remove_swnode_recursive(swnode); 987 dev->pdev = NULL; 988 } 989 990 static ssize_t 991 gpio_sim_device_config_live_store(struct config_item *item, 992 const char *page, size_t count) 993 { 994 struct gpio_sim_device *dev = to_gpio_sim_device(item); 995 bool live; 996 int ret; 997 998 ret = kstrtobool(page, &live); 999 if (ret) 1000 return ret; 1001 1002 guard(mutex)(&dev->lock); 1003 1004 if (live == gpio_sim_device_is_live_unlocked(dev)) 1005 ret = -EPERM; 1006 else if (live) 1007 ret = gpio_sim_device_activate_unlocked(dev); 1008 else 1009 gpio_sim_device_deactivate_unlocked(dev); 1010 1011 return ret ?: count; 1012 } 1013 1014 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1015 1016 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1017 &gpio_sim_device_config_attr_dev_name, 1018 &gpio_sim_device_config_attr_live, 1019 NULL 1020 }; 1021 1022 struct gpio_sim_chip_name_ctx { 1023 struct fwnode_handle *swnode; 1024 char *page; 1025 }; 1026 1027 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1028 { 1029 struct gpio_sim_chip_name_ctx *ctx = data; 1030 1031 /* This would be the sysfs device exported in /sys/class/gpio. */ 1032 if (dev->class) 1033 return 0; 1034 1035 if (device_match_fwnode(dev, ctx->swnode)) 1036 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1037 1038 return 0; 1039 } 1040 1041 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1042 char *page) 1043 { 1044 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1045 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1046 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1047 1048 guard(mutex)(&dev->lock); 1049 1050 if (gpio_sim_device_is_live_unlocked(dev)) 1051 return device_for_each_child(&dev->pdev->dev, &ctx, 1052 gpio_sim_emit_chip_name); 1053 1054 return sprintf(page, "none\n"); 1055 } 1056 1057 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1058 1059 static ssize_t 1060 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1061 { 1062 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1063 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1064 1065 guard(mutex)(&dev->lock); 1066 1067 return sprintf(page, "%s\n", bank->label ?: ""); 1068 } 1069 1070 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1071 const char *page, size_t count) 1072 { 1073 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1074 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1075 char *trimmed; 1076 1077 guard(mutex)(&dev->lock); 1078 1079 if (gpio_sim_device_is_live_unlocked(dev)) 1080 return -EBUSY; 1081 1082 trimmed = gpio_sim_strdup_trimmed(page, count); 1083 if (!trimmed) 1084 return -ENOMEM; 1085 1086 kfree(bank->label); 1087 bank->label = trimmed; 1088 1089 return count; 1090 } 1091 1092 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1093 1094 static ssize_t 1095 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1096 { 1097 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1098 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1099 1100 guard(mutex)(&dev->lock); 1101 1102 return sprintf(page, "%u\n", bank->num_lines); 1103 } 1104 1105 static ssize_t 1106 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1107 const char *page, size_t count) 1108 { 1109 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1110 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1111 unsigned int num_lines; 1112 int ret; 1113 1114 ret = kstrtouint(page, 0, &num_lines); 1115 if (ret) 1116 return ret; 1117 1118 if (num_lines == 0) 1119 return -EINVAL; 1120 1121 guard(mutex)(&dev->lock); 1122 1123 if (gpio_sim_device_is_live_unlocked(dev)) 1124 return -EBUSY; 1125 1126 bank->num_lines = num_lines; 1127 1128 return count; 1129 } 1130 1131 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1132 1133 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1134 &gpio_sim_bank_config_attr_chip_name, 1135 &gpio_sim_bank_config_attr_label, 1136 &gpio_sim_bank_config_attr_num_lines, 1137 NULL 1138 }; 1139 1140 static ssize_t 1141 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1142 { 1143 struct gpio_sim_line *line = to_gpio_sim_line(item); 1144 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1145 1146 guard(mutex)(&dev->lock); 1147 1148 return sprintf(page, "%s\n", line->name ?: ""); 1149 } 1150 1151 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1152 const char *page, size_t count) 1153 { 1154 struct gpio_sim_line *line = to_gpio_sim_line(item); 1155 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1156 char *trimmed; 1157 1158 guard(mutex)(&dev->lock); 1159 1160 if (gpio_sim_device_is_live_unlocked(dev)) 1161 return -EBUSY; 1162 1163 trimmed = gpio_sim_strdup_trimmed(page, count); 1164 if (!trimmed) 1165 return -ENOMEM; 1166 1167 kfree(line->name); 1168 line->name = trimmed; 1169 1170 return count; 1171 } 1172 1173 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1174 1175 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1176 &gpio_sim_line_config_attr_name, 1177 NULL 1178 }; 1179 1180 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1181 char *page) 1182 { 1183 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1184 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1185 1186 guard(mutex)(&dev->lock); 1187 1188 return sprintf(page, "%s\n", hog->name ?: ""); 1189 } 1190 1191 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1192 const char *page, size_t count) 1193 { 1194 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1195 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1196 char *trimmed; 1197 1198 guard(mutex)(&dev->lock); 1199 1200 if (gpio_sim_device_is_live_unlocked(dev)) 1201 return -EBUSY; 1202 1203 trimmed = gpio_sim_strdup_trimmed(page, count); 1204 if (!trimmed) 1205 return -ENOMEM; 1206 1207 kfree(hog->name); 1208 hog->name = trimmed; 1209 1210 return count; 1211 } 1212 1213 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1214 1215 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1216 char *page) 1217 { 1218 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1219 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1220 char *repr; 1221 int dir; 1222 1223 scoped_guard(mutex, &dev->lock) 1224 dir = hog->dir; 1225 1226 switch (dir) { 1227 case GPIOD_IN: 1228 repr = "input"; 1229 break; 1230 case GPIOD_OUT_HIGH: 1231 repr = "output-high"; 1232 break; 1233 case GPIOD_OUT_LOW: 1234 repr = "output-low"; 1235 break; 1236 default: 1237 /* This would be a programmer bug. */ 1238 WARN(1, "Unexpected hog direction value: %d", dir); 1239 return -EINVAL; 1240 } 1241 1242 return sprintf(page, "%s\n", repr); 1243 } 1244 1245 static ssize_t 1246 gpio_sim_hog_config_direction_store(struct config_item *item, 1247 const char *page, size_t count) 1248 { 1249 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1250 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1251 int dir; 1252 1253 guard(mutex)(&dev->lock); 1254 1255 if (gpio_sim_device_is_live_unlocked(dev)) 1256 return -EBUSY; 1257 1258 if (sysfs_streq(page, "input")) 1259 dir = GPIOD_IN; 1260 else if (sysfs_streq(page, "output-high")) 1261 dir = GPIOD_OUT_HIGH; 1262 else if (sysfs_streq(page, "output-low")) 1263 dir = GPIOD_OUT_LOW; 1264 else 1265 return -EINVAL; 1266 1267 hog->dir = dir; 1268 1269 return count; 1270 } 1271 1272 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1273 1274 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1275 &gpio_sim_hog_config_attr_name, 1276 &gpio_sim_hog_config_attr_direction, 1277 NULL 1278 }; 1279 1280 static void gpio_sim_hog_config_item_release(struct config_item *item) 1281 { 1282 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1283 struct gpio_sim_line *line = hog->parent; 1284 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1285 1286 scoped_guard(mutex, &dev->lock) 1287 line->hog = NULL; 1288 1289 kfree(hog->name); 1290 kfree(hog); 1291 } 1292 1293 static struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1294 .release = gpio_sim_hog_config_item_release, 1295 }; 1296 1297 static const struct config_item_type gpio_sim_hog_config_type = { 1298 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1299 .ct_attrs = gpio_sim_hog_config_attrs, 1300 .ct_owner = THIS_MODULE, 1301 }; 1302 1303 static struct config_item * 1304 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1305 { 1306 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1307 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1308 struct gpio_sim_hog *hog; 1309 1310 if (strcmp(name, "hog") != 0) 1311 return ERR_PTR(-EINVAL); 1312 1313 guard(mutex)(&dev->lock); 1314 1315 hog = kzalloc(sizeof(*hog), GFP_KERNEL); 1316 if (!hog) 1317 return ERR_PTR(-ENOMEM); 1318 1319 config_item_init_type_name(&hog->item, name, 1320 &gpio_sim_hog_config_type); 1321 1322 hog->dir = GPIOD_IN; 1323 hog->name = NULL; 1324 hog->parent = line; 1325 line->hog = hog; 1326 1327 return &hog->item; 1328 } 1329 1330 static void gpio_sim_line_config_group_release(struct config_item *item) 1331 { 1332 struct gpio_sim_line *line = to_gpio_sim_line(item); 1333 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1334 1335 scoped_guard(mutex, &dev->lock) 1336 list_del(&line->siblings); 1337 1338 kfree(line->name); 1339 kfree(line); 1340 } 1341 1342 static struct configfs_item_operations gpio_sim_line_config_item_ops = { 1343 .release = gpio_sim_line_config_group_release, 1344 }; 1345 1346 static struct configfs_group_operations gpio_sim_line_config_group_ops = { 1347 .make_item = gpio_sim_line_config_make_hog_item, 1348 }; 1349 1350 static const struct config_item_type gpio_sim_line_config_type = { 1351 .ct_item_ops = &gpio_sim_line_config_item_ops, 1352 .ct_group_ops = &gpio_sim_line_config_group_ops, 1353 .ct_attrs = gpio_sim_line_config_attrs, 1354 .ct_owner = THIS_MODULE, 1355 }; 1356 1357 static struct config_group * 1358 gpio_sim_bank_config_make_line_group(struct config_group *group, 1359 const char *name) 1360 { 1361 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1362 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1363 struct gpio_sim_line *line; 1364 unsigned int offset; 1365 int ret, nchar; 1366 1367 ret = sscanf(name, "line%u%n", &offset, &nchar); 1368 if (ret != 1 || nchar != strlen(name)) 1369 return ERR_PTR(-EINVAL); 1370 1371 guard(mutex)(&dev->lock); 1372 1373 if (gpio_sim_device_is_live_unlocked(dev)) 1374 return ERR_PTR(-EBUSY); 1375 1376 line = kzalloc(sizeof(*line), GFP_KERNEL); 1377 if (!line) 1378 return ERR_PTR(-ENOMEM); 1379 1380 config_group_init_type_name(&line->group, name, 1381 &gpio_sim_line_config_type); 1382 1383 line->parent = bank; 1384 line->offset = offset; 1385 list_add_tail(&line->siblings, &bank->line_list); 1386 1387 return &line->group; 1388 } 1389 1390 static void gpio_sim_bank_config_group_release(struct config_item *item) 1391 { 1392 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1393 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1394 1395 scoped_guard(mutex, &dev->lock) 1396 list_del(&bank->siblings); 1397 1398 kfree(bank->label); 1399 kfree(bank); 1400 } 1401 1402 static struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1403 .release = gpio_sim_bank_config_group_release, 1404 }; 1405 1406 static struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1407 .make_group = gpio_sim_bank_config_make_line_group, 1408 }; 1409 1410 static const struct config_item_type gpio_sim_bank_config_group_type = { 1411 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1412 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1413 .ct_attrs = gpio_sim_bank_config_attrs, 1414 .ct_owner = THIS_MODULE, 1415 }; 1416 1417 static struct config_group * 1418 gpio_sim_device_config_make_bank_group(struct config_group *group, 1419 const char *name) 1420 { 1421 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1422 struct gpio_sim_bank *bank; 1423 1424 guard(mutex)(&dev->lock); 1425 1426 if (gpio_sim_device_is_live_unlocked(dev)) 1427 return ERR_PTR(-EBUSY); 1428 1429 bank = kzalloc(sizeof(*bank), GFP_KERNEL); 1430 if (!bank) 1431 return ERR_PTR(-ENOMEM); 1432 1433 config_group_init_type_name(&bank->group, name, 1434 &gpio_sim_bank_config_group_type); 1435 bank->num_lines = 1; 1436 bank->parent = dev; 1437 INIT_LIST_HEAD(&bank->line_list); 1438 list_add_tail(&bank->siblings, &dev->bank_list); 1439 1440 return &bank->group; 1441 } 1442 1443 static void gpio_sim_device_config_group_release(struct config_item *item) 1444 { 1445 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1446 1447 scoped_guard(mutex, &dev->lock) { 1448 if (gpio_sim_device_is_live_unlocked(dev)) 1449 gpio_sim_device_deactivate_unlocked(dev); 1450 } 1451 1452 mutex_destroy(&dev->lock); 1453 ida_free(&gpio_sim_ida, dev->id); 1454 kfree(dev); 1455 } 1456 1457 static struct configfs_item_operations gpio_sim_device_config_item_ops = { 1458 .release = gpio_sim_device_config_group_release, 1459 }; 1460 1461 static struct configfs_group_operations gpio_sim_device_config_group_ops = { 1462 .make_group = gpio_sim_device_config_make_bank_group, 1463 }; 1464 1465 static const struct config_item_type gpio_sim_device_config_group_type = { 1466 .ct_item_ops = &gpio_sim_device_config_item_ops, 1467 .ct_group_ops = &gpio_sim_device_config_group_ops, 1468 .ct_attrs = gpio_sim_device_config_attrs, 1469 .ct_owner = THIS_MODULE, 1470 }; 1471 1472 static struct config_group * 1473 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1474 { 1475 int id; 1476 1477 struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev), 1478 GFP_KERNEL); 1479 if (!dev) 1480 return ERR_PTR(-ENOMEM); 1481 1482 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1483 if (id < 0) 1484 return ERR_PTR(id); 1485 1486 config_group_init_type_name(&dev->group, name, 1487 &gpio_sim_device_config_group_type); 1488 dev->id = id; 1489 mutex_init(&dev->lock); 1490 INIT_LIST_HEAD(&dev->bank_list); 1491 1492 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call; 1493 init_completion(&dev->probe_completion); 1494 1495 return &no_free_ptr(dev)->group; 1496 } 1497 1498 static struct configfs_group_operations gpio_sim_config_group_ops = { 1499 .make_group = gpio_sim_config_make_device_group, 1500 }; 1501 1502 static const struct config_item_type gpio_sim_config_type = { 1503 .ct_group_ops = &gpio_sim_config_group_ops, 1504 .ct_owner = THIS_MODULE, 1505 }; 1506 1507 static struct configfs_subsystem gpio_sim_config_subsys = { 1508 .su_group = { 1509 .cg_item = { 1510 .ci_namebuf = "gpio-sim", 1511 .ci_type = &gpio_sim_config_type, 1512 }, 1513 }, 1514 }; 1515 1516 static int __init gpio_sim_init(void) 1517 { 1518 int ret; 1519 1520 ret = platform_driver_register(&gpio_sim_driver); 1521 if (ret) { 1522 pr_err("Error %d while registering the platform driver\n", ret); 1523 return ret; 1524 } 1525 1526 config_group_init(&gpio_sim_config_subsys.su_group); 1527 mutex_init(&gpio_sim_config_subsys.su_mutex); 1528 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1529 if (ret) { 1530 pr_err("Error %d while registering the configfs subsystem %s\n", 1531 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1532 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1533 platform_driver_unregister(&gpio_sim_driver); 1534 return ret; 1535 } 1536 1537 return 0; 1538 } 1539 module_init(gpio_sim_init); 1540 1541 static void __exit gpio_sim_exit(void) 1542 { 1543 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1544 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1545 platform_driver_unregister(&gpio_sim_driver); 1546 } 1547 module_exit(gpio_sim_exit); 1548 1549 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl"); 1550 MODULE_DESCRIPTION("GPIO Simulator Module"); 1551 MODULE_LICENSE("GPL"); 1552