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/array_size.h> 11 #include <linux/bitmap.h> 12 #include <linux/cleanup.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/lockdep.h> 25 #include <linux/minmax.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/seq_file.h> 32 #include <linux/slab.h> 33 #include <linux/string.h> 34 #include <linux/string_helpers.h> 35 #include <linux/sysfs.h> 36 #include <linux/types.h> 37 38 #define GPIO_SIM_NGPIO_MAX 1024 39 #define GPIO_SIM_PROP_MAX 5 /* Max 4 properties + sentinel. */ 40 #define GPIO_SIM_HOG_PROP_MAX 5 41 #define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */ 42 43 static DEFINE_IDA(gpio_sim_ida); 44 45 struct gpio_sim_chip { 46 struct gpio_chip gc; 47 struct device *dev; 48 unsigned long *request_map; 49 unsigned long *direction_map; 50 unsigned long *value_map; 51 unsigned long *pull_map; 52 struct irq_domain *irq_sim; 53 struct mutex lock; 54 const struct attribute_group **attr_groups; 55 }; 56 57 struct gpio_sim_attribute { 58 struct device_attribute dev_attr; 59 unsigned int offset; 60 }; 61 62 static struct gpio_sim_attribute * 63 to_gpio_sim_attr(struct device_attribute *dev_attr) 64 { 65 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 66 } 67 68 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 69 unsigned int offset, int value) 70 { 71 int irq, irq_type, ret; 72 73 guard(mutex)(&chip->lock); 74 75 if (test_bit(offset, chip->request_map) && 76 test_bit(offset, chip->direction_map)) { 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(offset, chip->request_map) || 104 test_bit(offset, chip->direction_map)) 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 int 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 return 0; 129 } 130 131 static int gpio_sim_get_multiple(struct gpio_chip *gc, 132 unsigned long *mask, unsigned long *bits) 133 { 134 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 135 136 scoped_guard(mutex, &chip->lock) 137 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 138 139 return 0; 140 } 141 142 static int gpio_sim_set_multiple(struct gpio_chip *gc, 143 unsigned long *mask, unsigned long *bits) 144 { 145 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 146 147 scoped_guard(mutex, &chip->lock) 148 bitmap_replace(chip->value_map, chip->value_map, bits, mask, 149 gc->ngpio); 150 151 return 0; 152 } 153 154 static int gpio_sim_direction_output(struct gpio_chip *gc, 155 unsigned int offset, int value) 156 { 157 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 158 159 scoped_guard(mutex, &chip->lock) { 160 __clear_bit(offset, chip->direction_map); 161 __assign_bit(offset, chip->value_map, value); 162 } 163 164 return 0; 165 } 166 167 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 168 { 169 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 170 171 scoped_guard(mutex, &chip->lock) 172 __set_bit(offset, chip->direction_map); 173 174 return 0; 175 } 176 177 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 178 { 179 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 180 int direction; 181 182 scoped_guard(mutex, &chip->lock) 183 direction = !!test_bit(offset, chip->direction_map); 184 185 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; 186 } 187 188 static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset, 189 unsigned long config) 190 { 191 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 192 193 switch (pinconf_to_config_param(config)) { 194 case PIN_CONFIG_BIAS_PULL_UP: 195 return gpio_sim_apply_pull(chip, offset, 1); 196 case PIN_CONFIG_BIAS_PULL_DOWN: 197 return gpio_sim_apply_pull(chip, offset, 0); 198 default: 199 break; 200 } 201 202 return -ENOTSUPP; 203 } 204 205 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 206 { 207 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 208 209 return irq_create_mapping(chip->irq_sim, offset); 210 } 211 212 static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset) 213 { 214 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 215 216 scoped_guard(mutex, &chip->lock) 217 __set_bit(offset, chip->request_map); 218 219 return 0; 220 } 221 222 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 223 { 224 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 225 226 scoped_guard(mutex, &chip->lock) { 227 __assign_bit(offset, chip->value_map, 228 !!test_bit(offset, chip->pull_map)); 229 __clear_bit(offset, chip->request_map); 230 } 231 } 232 233 static int gpio_sim_irq_requested(struct irq_domain *domain, 234 irq_hw_number_t hwirq, void *data) 235 { 236 struct gpio_sim_chip *chip = data; 237 238 return gpiochip_lock_as_irq(&chip->gc, hwirq); 239 } 240 241 static void gpio_sim_irq_released(struct irq_domain *domain, 242 irq_hw_number_t hwirq, void *data) 243 { 244 struct gpio_sim_chip *chip = data; 245 246 gpiochip_unlock_as_irq(&chip->gc, hwirq); 247 } 248 249 static const struct irq_sim_ops gpio_sim_irq_sim_ops = { 250 .irq_sim_irq_requested = gpio_sim_irq_requested, 251 .irq_sim_irq_released = gpio_sim_irq_released, 252 }; 253 254 static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc) 255 { 256 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 257 const char *label; 258 int i; 259 260 guard(mutex)(&chip->lock); 261 262 for_each_hwgpio(gc, i, label) 263 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n", i, 264 label ?: "<unused>", 265 test_bit(i, chip->direction_map) ? "input" : 266 test_bit(i, chip->value_map) ? "output-high" : 267 "output-low", 268 test_bit(i, chip->pull_map) ? "pull-up" : 269 "pull-down"); 270 } 271 272 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 273 struct device_attribute *attr, char *buf) 274 { 275 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 276 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 277 int val; 278 279 scoped_guard(mutex, &chip->lock) 280 val = !!test_bit(line_attr->offset, chip->value_map); 281 282 return sysfs_emit(buf, "%d\n", val); 283 } 284 285 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 286 struct device_attribute *attr, 287 const char *buf, size_t count) 288 { 289 /* 290 * Not assigning this function will result in write() returning -EIO 291 * which is confusing. Return -EPERM explicitly. 292 */ 293 return -EPERM; 294 } 295 296 static const char *const gpio_sim_sysfs_pull_strings[] = { 297 [0] = "pull-down", 298 [1] = "pull-up", 299 }; 300 301 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 302 struct device_attribute *attr, 303 char *buf) 304 { 305 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 306 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 307 int pull; 308 309 scoped_guard(mutex, &chip->lock) 310 pull = !!test_bit(line_attr->offset, chip->pull_map); 311 312 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 313 } 314 315 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 316 struct device_attribute *attr, 317 const char *buf, size_t len) 318 { 319 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 320 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 321 int ret, pull; 322 323 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 324 if (pull < 0) 325 return pull; 326 327 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 328 if (ret) 329 return ret; 330 331 return len; 332 } 333 334 static void gpio_sim_put_device(void *data) 335 { 336 struct device *dev = data; 337 338 put_device(dev); 339 } 340 341 static void gpio_sim_dispose_mappings(void *data) 342 { 343 struct gpio_sim_chip *chip = data; 344 unsigned int i; 345 346 for (i = 0; i < chip->gc.ngpio; i++) 347 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 348 } 349 350 static void gpio_sim_sysfs_remove(void *data) 351 { 352 struct gpio_sim_chip *chip = data; 353 354 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups); 355 } 356 357 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 358 { 359 struct device_attribute *val_dev_attr, *pull_dev_attr; 360 struct gpio_sim_attribute *val_attr, *pull_attr; 361 unsigned int num_lines = chip->gc.ngpio; 362 struct device *dev = chip->gc.parent; 363 struct attribute_group *attr_group; 364 struct attribute **attrs; 365 int i, ret; 366 367 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 368 num_lines + 1, GFP_KERNEL); 369 if (!chip->attr_groups) 370 return -ENOMEM; 371 372 for (i = 0; i < num_lines; i++) { 373 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 374 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 375 GFP_KERNEL); 376 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 377 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 378 if (!attr_group || !attrs || !val_attr || !pull_attr) 379 return -ENOMEM; 380 381 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 382 "sim_gpio%u", i); 383 if (!attr_group->name) 384 return -ENOMEM; 385 386 val_attr->offset = pull_attr->offset = i; 387 388 val_dev_attr = &val_attr->dev_attr; 389 pull_dev_attr = &pull_attr->dev_attr; 390 391 sysfs_attr_init(&val_dev_attr->attr); 392 sysfs_attr_init(&pull_dev_attr->attr); 393 394 val_dev_attr->attr.name = "value"; 395 pull_dev_attr->attr.name = "pull"; 396 397 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 398 399 val_dev_attr->show = gpio_sim_sysfs_val_show; 400 val_dev_attr->store = gpio_sim_sysfs_val_store; 401 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 402 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 403 404 attrs[0] = &val_dev_attr->attr; 405 attrs[1] = &pull_dev_attr->attr; 406 407 attr_group->attrs = attrs; 408 chip->attr_groups[i] = attr_group; 409 } 410 411 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups); 412 if (ret) 413 return ret; 414 415 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 416 } 417 418 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 419 { 420 struct gpio_sim_chip *chip; 421 struct gpio_chip *gc; 422 const char *label; 423 u32 num_lines; 424 int ret; 425 426 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 427 if (ret) 428 return ret; 429 430 if (num_lines > GPIO_SIM_NGPIO_MAX) 431 return -ERANGE; 432 433 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 434 if (ret) { 435 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP", 436 dev_name(dev), swnode); 437 if (!label) 438 return -ENOMEM; 439 } 440 441 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 442 if (!chip) 443 return -ENOMEM; 444 445 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 446 if (!chip->request_map) 447 return -ENOMEM; 448 449 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 450 if (!chip->direction_map) 451 return -ENOMEM; 452 453 /* Default to input mode. */ 454 bitmap_fill(chip->direction_map, num_lines); 455 456 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 457 if (!chip->value_map) 458 return -ENOMEM; 459 460 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 461 if (!chip->pull_map) 462 return -ENOMEM; 463 464 chip->irq_sim = devm_irq_domain_create_sim_full(dev, swnode, num_lines, 465 &gpio_sim_irq_sim_ops, 466 chip); 467 if (IS_ERR(chip->irq_sim)) 468 return PTR_ERR(chip->irq_sim); 469 470 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 471 if (ret) 472 return ret; 473 474 ret = devm_mutex_init(dev, &chip->lock); 475 if (ret) 476 return ret; 477 478 gc = &chip->gc; 479 gc->base = -1; 480 gc->ngpio = num_lines; 481 gc->label = label; 482 gc->owner = THIS_MODULE; 483 gc->parent = dev; 484 gc->fwnode = swnode; 485 gc->get = gpio_sim_get; 486 gc->set = gpio_sim_set; 487 gc->get_multiple = gpio_sim_get_multiple; 488 gc->set_multiple = gpio_sim_set_multiple; 489 gc->direction_output = gpio_sim_direction_output; 490 gc->direction_input = gpio_sim_direction_input; 491 gc->get_direction = gpio_sim_get_direction; 492 gc->set_config = gpio_sim_set_config; 493 gc->to_irq = gpio_sim_to_irq; 494 gc->request = gpio_sim_request; 495 gc->free = gpio_sim_free; 496 gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show); 497 gc->can_sleep = true; 498 499 ret = devm_gpiochip_add_data(dev, gc, chip); 500 if (ret) 501 return ret; 502 503 chip->dev = device_find_child(dev, swnode, device_match_fwnode); 504 if (!chip->dev) 505 return -ENODEV; 506 507 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev); 508 if (ret) 509 return ret; 510 511 /* Used by sysfs callbacks. */ 512 dev_set_drvdata(chip->dev, chip); 513 514 return gpio_sim_setup_sysfs(chip); 515 } 516 517 static int gpio_sim_probe(struct platform_device *pdev) 518 { 519 struct device *dev = &pdev->dev; 520 int ret; 521 522 device_for_each_child_node_scoped(dev, swnode) { 523 ret = gpio_sim_add_bank(swnode, dev); 524 if (ret) 525 return ret; 526 } 527 528 return 0; 529 } 530 531 static const struct of_device_id gpio_sim_of_match[] = { 532 { .compatible = "gpio-simulator" }, 533 { } 534 }; 535 MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 536 537 static struct platform_driver gpio_sim_driver = { 538 .driver = { 539 .name = "gpio-sim", 540 .of_match_table = gpio_sim_of_match, 541 }, 542 .probe = gpio_sim_probe, 543 }; 544 545 struct gpio_sim_device { 546 struct platform_device *pdev; 547 struct config_group group; 548 549 int id; 550 551 /* 552 * Each configfs filesystem operation is protected with the subsystem 553 * mutex. Each separate attribute is protected with the buffer mutex. 554 * This structure however can be modified by callbacks of different 555 * attributes so we need another lock. 556 * 557 * We use this lock for protecting all data structures owned by this 558 * object too. 559 */ 560 struct mutex lock; 561 562 struct list_head bank_list; 563 }; 564 565 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 566 { 567 struct config_group *group = to_config_group(item); 568 569 return container_of(group, struct gpio_sim_device, group); 570 } 571 572 struct gpio_sim_bank { 573 struct config_group group; 574 575 /* 576 * We could have used the ci_parent field of the config_item but 577 * configfs is stupid and calls the item's release callback after 578 * already having cleared the parent pointer even though the parent 579 * is guaranteed to survive the child... 580 * 581 * So we need to store the pointer to the parent struct here. We can 582 * dereference it anywhere we need with no checks and no locking as 583 * it's guaranteed to survive the children and protected by configfs 584 * locks. 585 * 586 * Same for other structures. 587 */ 588 struct gpio_sim_device *parent; 589 struct list_head siblings; 590 591 char *label; 592 unsigned int num_lines; 593 594 struct list_head line_list; 595 596 struct fwnode_handle *swnode; 597 }; 598 599 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 600 { 601 struct config_group *group = to_config_group(item); 602 603 return container_of(group, struct gpio_sim_bank, group); 604 } 605 606 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 607 { 608 return bank->label && *bank->label; 609 } 610 611 static struct gpio_sim_device * 612 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 613 { 614 return bank->parent; 615 } 616 617 struct gpio_sim_hog; 618 619 struct gpio_sim_line { 620 struct config_group group; 621 622 struct gpio_sim_bank *parent; 623 struct list_head siblings; 624 625 unsigned int offset; 626 char *name; 627 bool valid; 628 629 /* There can only be one hog per line. */ 630 struct gpio_sim_hog *hog; 631 }; 632 633 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 634 { 635 struct config_group *group = to_config_group(item); 636 637 return container_of(group, struct gpio_sim_line, group); 638 } 639 640 static struct gpio_sim_device * 641 gpio_sim_line_get_device(struct gpio_sim_line *line) 642 { 643 struct gpio_sim_bank *bank = line->parent; 644 645 return gpio_sim_bank_get_device(bank); 646 } 647 648 struct gpio_sim_hog { 649 struct config_item item; 650 struct gpio_sim_line *parent; 651 652 char *name; 653 int dir; 654 bool active_low; 655 }; 656 657 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 658 { 659 return container_of(item, struct gpio_sim_hog, item); 660 } 661 662 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 663 { 664 struct gpio_sim_line *line = hog->parent; 665 666 return gpio_sim_line_get_device(line); 667 } 668 669 static bool gpio_sim_device_is_live(struct gpio_sim_device *dev) 670 { 671 lockdep_assert_held(&dev->lock); 672 673 return !!dev->pdev; 674 } 675 676 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 677 { 678 char *trimmed; 679 680 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 681 if (!trimmed) 682 return NULL; 683 684 return strim(trimmed); 685 } 686 687 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 688 char *page) 689 { 690 struct gpio_sim_device *dev = to_gpio_sim_device(item); 691 struct platform_device *pdev; 692 693 guard(mutex)(&dev->lock); 694 695 pdev = dev->pdev; 696 if (pdev) 697 return sysfs_emit(page, "%s\n", dev_name(&pdev->dev)); 698 699 return sysfs_emit(page, "gpio-sim.%d\n", dev->id); 700 } 701 702 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 703 704 static ssize_t 705 gpio_sim_device_config_live_show(struct config_item *item, char *page) 706 { 707 struct gpio_sim_device *dev = to_gpio_sim_device(item); 708 bool live; 709 710 scoped_guard(mutex, &dev->lock) 711 live = gpio_sim_device_is_live(dev); 712 713 return sysfs_emit(page, "%c\n", live ? '1' : '0'); 714 } 715 716 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank) 717 { 718 struct gpio_sim_line *line; 719 unsigned int size = 0; 720 721 list_for_each_entry(line, &bank->line_list, siblings) { 722 if (!line->name || (line->offset >= bank->num_lines)) 723 continue; 724 725 size = max(size, line->offset + 1); 726 } 727 728 return size; 729 } 730 731 static void 732 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 733 { 734 struct gpio_sim_line *line; 735 736 list_for_each_entry(line, &bank->line_list, siblings) { 737 if (!line->name || (line->offset >= bank->num_lines)) 738 continue; 739 740 line_names[line->offset] = line->name; 741 } 742 } 743 744 static unsigned int gpio_sim_get_reserved_ranges_size(struct gpio_sim_bank *bank) 745 { 746 struct gpio_sim_line *line; 747 unsigned int size = 0; 748 749 list_for_each_entry(line, &bank->line_list, siblings) { 750 if (line->valid) 751 continue; 752 753 size += 2; 754 } 755 756 return size; 757 } 758 759 static void gpio_sim_set_reserved_ranges(struct gpio_sim_bank *bank, 760 u32 *ranges) 761 { 762 struct gpio_sim_line *line; 763 int i = 0; 764 765 list_for_each_entry(line, &bank->line_list, siblings) { 766 if (line->valid) 767 continue; 768 769 ranges[i++] = line->offset; 770 ranges[i++] = 1; 771 } 772 } 773 774 static struct fwnode_handle * 775 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 776 struct fwnode_handle *parent) 777 { 778 unsigned int prop_idx = 0, line_names_size, ranges_size; 779 struct property_entry properties[GPIO_SIM_PROP_MAX]; 780 char **line_names __free(kfree) = NULL; 781 u32 *ranges __free(kfree) = NULL; 782 783 memset(properties, 0, sizeof(properties)); 784 785 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 786 787 if (gpio_sim_bank_has_label(bank)) 788 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 789 bank->label); 790 791 line_names_size = gpio_sim_get_line_names_size(bank); 792 if (line_names_size) { 793 line_names = kzalloc_objs(*line_names, line_names_size); 794 if (!line_names) 795 return ERR_PTR(-ENOMEM); 796 797 gpio_sim_set_line_names(bank, line_names); 798 799 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 800 "gpio-line-names", 801 line_names, line_names_size); 802 } 803 804 ranges_size = gpio_sim_get_reserved_ranges_size(bank); 805 if (ranges_size) { 806 ranges = kcalloc(ranges_size, sizeof(u32), GFP_KERNEL); 807 if (!ranges) 808 return ERR_PTR(-ENOMEM); 809 810 gpio_sim_set_reserved_ranges(bank, ranges); 811 812 properties[prop_idx++] = PROPERTY_ENTRY_U32_ARRAY_LEN( 813 "gpio-reserved-ranges", 814 ranges, ranges_size); 815 } 816 817 return fwnode_create_software_node(properties, parent); 818 } 819 820 static int gpio_sim_bank_add_hogs(struct gpio_sim_bank *bank) 821 { 822 struct property_entry properties[GPIO_SIM_HOG_PROP_MAX]; 823 struct fwnode_handle *swnode; 824 struct gpio_sim_line *line; 825 struct gpio_sim_hog *hog; 826 unsigned int idx; 827 u32 gpios[2]; 828 829 list_for_each_entry(line, &bank->line_list, siblings) { 830 if (!line->hog) 831 continue; 832 833 hog = line->hog; 834 835 gpios[0] = line->offset; 836 gpios[1] = hog->active_low ? 1 : 0; 837 838 memset(properties, 0, sizeof(properties)); 839 840 idx = 0; 841 properties[idx++] = PROPERTY_ENTRY_BOOL("gpio-hog"); 842 properties[idx++] = PROPERTY_ENTRY_U32_ARRAY("gpios", gpios); 843 properties[idx++] = PROPERTY_ENTRY_STRING("line-name", hog->name); 844 845 switch (hog->dir) { 846 case GPIOD_IN: 847 properties[idx++] = PROPERTY_ENTRY_BOOL("input"); 848 break; 849 case GPIOD_OUT_HIGH: 850 properties[idx++] = PROPERTY_ENTRY_BOOL("output-high"); 851 break; 852 case GPIOD_OUT_LOW: 853 properties[idx++] = PROPERTY_ENTRY_BOOL("output-low"); 854 break; 855 default: 856 /* Would have been validated at configfs store. */ 857 WARN(1, "Unexpected hog direction value: %d", hog->dir); 858 return -EINVAL; 859 } 860 861 swnode = fwnode_create_software_node(properties, bank->swnode); 862 if (IS_ERR(swnode)) 863 return PTR_ERR(swnode); 864 } 865 866 return 0; 867 } 868 869 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 870 { 871 struct fwnode_handle *child; 872 873 fwnode_for_each_child_node(swnode, child) 874 gpio_sim_remove_swnode_recursive(child); 875 876 fwnode_remove_software_node(swnode); 877 } 878 879 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 880 { 881 struct gpio_sim_bank *this, *pos; 882 883 list_for_each_entry(this, &dev->bank_list, siblings) { 884 list_for_each_entry(pos, &dev->bank_list, siblings) { 885 if (this == pos || (!this->label || !pos->label)) 886 continue; 887 888 if (strcmp(this->label, pos->label) == 0) 889 return true; 890 } 891 } 892 893 return false; 894 } 895 896 static int gpio_sim_device_activate(struct gpio_sim_device *dev) 897 { 898 struct platform_device_info pdevinfo; 899 struct platform_device *pdev; 900 struct fwnode_handle *swnode; 901 struct gpio_sim_bank *bank; 902 int ret = 0; 903 904 lockdep_assert_held(&dev->lock); 905 906 if (list_empty(&dev->bank_list)) 907 return -ENODATA; 908 909 /* 910 * Non-unique GPIO device labels are a corner-case we don't support 911 * as it would interfere with machine hogging mechanism and has little 912 * use in real life. 913 */ 914 if (gpio_sim_bank_labels_non_unique(dev)) 915 return -EINVAL; 916 917 memset(&pdevinfo, 0, sizeof(pdevinfo)); 918 919 swnode = fwnode_create_software_node(NULL, NULL); 920 if (IS_ERR(swnode)) 921 return PTR_ERR(swnode); 922 923 list_for_each_entry(bank, &dev->bank_list, siblings) { 924 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 925 if (IS_ERR(bank->swnode)) { 926 ret = PTR_ERR(bank->swnode); 927 goto err_remove_swnode; 928 } 929 930 ret = gpio_sim_bank_add_hogs(bank); 931 if (ret) 932 goto err_remove_swnode; 933 } 934 935 pdevinfo.name = "gpio-sim"; 936 pdevinfo.fwnode = swnode; 937 pdevinfo.id = dev->id; 938 939 pdev = platform_device_register_full(&pdevinfo); 940 if (IS_ERR(pdev)) { 941 ret = PTR_ERR(pdev); 942 goto err_remove_swnode; 943 } 944 945 wait_for_device_probe(); 946 947 scoped_guard(device, &pdev->dev) { 948 if (!device_is_bound(&pdev->dev)) { 949 ret = -ENXIO; 950 goto err_unregister_pdev; 951 } 952 } 953 954 dev->pdev = pdev; 955 return 0; 956 957 err_unregister_pdev: 958 platform_device_unregister(pdev); 959 err_remove_swnode: 960 gpio_sim_remove_swnode_recursive(swnode); 961 962 return ret; 963 } 964 965 static void gpio_sim_device_deactivate(struct gpio_sim_device *dev) 966 { 967 struct fwnode_handle *swnode; 968 969 lockdep_assert_held(&dev->lock); 970 971 swnode = dev_fwnode(&dev->pdev->dev); 972 platform_device_unregister(dev->pdev); 973 dev->pdev = NULL; 974 gpio_sim_remove_swnode_recursive(swnode); 975 } 976 977 static void 978 gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock) 979 { 980 struct configfs_subsystem *subsys = dev->group.cg_subsys; 981 struct gpio_sim_bank *bank; 982 struct gpio_sim_line *line; 983 struct config_item *item; 984 985 /* 986 * The device only needs to depend on leaf entries. This is 987 * sufficient to lock up all the configfs entries that the 988 * instantiated, alive device depends on. 989 */ 990 list_for_each_entry(bank, &dev->bank_list, siblings) { 991 list_for_each_entry(line, &bank->line_list, siblings) { 992 item = line->hog ? &line->hog->item 993 : &line->group.cg_item; 994 995 if (lock) 996 WARN_ON(configfs_depend_item_unlocked(subsys, 997 item)); 998 else 999 configfs_undepend_item_unlocked(item); 1000 } 1001 } 1002 } 1003 1004 static ssize_t 1005 gpio_sim_device_config_live_store(struct config_item *item, 1006 const char *page, size_t count) 1007 { 1008 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1009 bool live; 1010 int ret; 1011 1012 ret = kstrtobool(page, &live); 1013 if (ret) 1014 return ret; 1015 1016 if (live) 1017 gpio_sim_device_lockup_configfs(dev, true); 1018 1019 scoped_guard(mutex, &dev->lock) { 1020 if (live == gpio_sim_device_is_live(dev)) 1021 ret = -EPERM; 1022 else if (live) 1023 ret = gpio_sim_device_activate(dev); 1024 else 1025 gpio_sim_device_deactivate(dev); 1026 } 1027 1028 /* 1029 * Undepend is required only if device disablement (live == 0) 1030 * succeeds or if device enablement (live == 1) fails. 1031 */ 1032 if (live == !!ret) 1033 gpio_sim_device_lockup_configfs(dev, false); 1034 1035 return ret ?: count; 1036 } 1037 1038 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1039 1040 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1041 &gpio_sim_device_config_attr_dev_name, 1042 &gpio_sim_device_config_attr_live, 1043 NULL 1044 }; 1045 1046 struct gpio_sim_chip_name_ctx { 1047 struct fwnode_handle *swnode; 1048 char *page; 1049 }; 1050 1051 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1052 { 1053 struct gpio_sim_chip_name_ctx *ctx = data; 1054 1055 /* This would be the sysfs device exported in /sys/class/gpio. */ 1056 if (dev->class) 1057 return 0; 1058 1059 if (device_match_fwnode(dev, ctx->swnode)) 1060 return sysfs_emit(ctx->page, "%s\n", dev_name(dev)); 1061 1062 return 0; 1063 } 1064 1065 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1066 char *page) 1067 { 1068 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1069 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1070 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1071 1072 guard(mutex)(&dev->lock); 1073 1074 if (gpio_sim_device_is_live(dev)) 1075 return device_for_each_child(&dev->pdev->dev, &ctx, 1076 gpio_sim_emit_chip_name); 1077 1078 return sysfs_emit(page, "none\n"); 1079 } 1080 1081 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1082 1083 static ssize_t 1084 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1085 { 1086 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1087 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1088 1089 guard(mutex)(&dev->lock); 1090 1091 return sysfs_emit(page, "%s\n", bank->label ?: ""); 1092 } 1093 1094 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1095 const char *page, size_t count) 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 char *trimmed; 1100 1101 guard(mutex)(&dev->lock); 1102 1103 if (gpio_sim_device_is_live(dev)) 1104 return -EBUSY; 1105 1106 trimmed = gpio_sim_strdup_trimmed(page, count); 1107 if (!trimmed) 1108 return -ENOMEM; 1109 1110 kfree(bank->label); 1111 bank->label = trimmed; 1112 1113 return count; 1114 } 1115 1116 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1117 1118 static ssize_t 1119 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1120 { 1121 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1122 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1123 1124 guard(mutex)(&dev->lock); 1125 1126 return sysfs_emit(page, "%u\n", bank->num_lines); 1127 } 1128 1129 static ssize_t 1130 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1131 const char *page, size_t count) 1132 { 1133 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1134 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1135 unsigned int num_lines; 1136 int ret; 1137 1138 ret = kstrtouint(page, 0, &num_lines); 1139 if (ret) 1140 return ret; 1141 1142 if (num_lines == 0) 1143 return -EINVAL; 1144 1145 guard(mutex)(&dev->lock); 1146 1147 if (gpio_sim_device_is_live(dev)) 1148 return -EBUSY; 1149 1150 bank->num_lines = num_lines; 1151 1152 return count; 1153 } 1154 1155 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1156 1157 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1158 &gpio_sim_bank_config_attr_chip_name, 1159 &gpio_sim_bank_config_attr_label, 1160 &gpio_sim_bank_config_attr_num_lines, 1161 NULL 1162 }; 1163 1164 static ssize_t 1165 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1166 { 1167 struct gpio_sim_line *line = to_gpio_sim_line(item); 1168 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1169 1170 guard(mutex)(&dev->lock); 1171 1172 return sysfs_emit(page, "%s\n", line->name ?: ""); 1173 } 1174 1175 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1176 const char *page, size_t count) 1177 { 1178 struct gpio_sim_line *line = to_gpio_sim_line(item); 1179 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1180 char *trimmed; 1181 1182 guard(mutex)(&dev->lock); 1183 1184 if (gpio_sim_device_is_live(dev)) 1185 return -EBUSY; 1186 1187 trimmed = gpio_sim_strdup_trimmed(page, count); 1188 if (!trimmed) 1189 return -ENOMEM; 1190 1191 kfree(line->name); 1192 line->name = trimmed; 1193 1194 return count; 1195 } 1196 1197 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1198 1199 static ssize_t 1200 gpio_sim_line_config_valid_show(struct config_item *item, char *page) 1201 { 1202 struct gpio_sim_line *line = to_gpio_sim_line(item); 1203 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1204 1205 guard(mutex)(&dev->lock); 1206 1207 return sysfs_emit(page, "%c\n", line->valid ? '1' : '0'); 1208 } 1209 1210 static ssize_t gpio_sim_line_config_valid_store(struct config_item *item, 1211 const char *page, size_t count) 1212 { 1213 struct gpio_sim_line *line = to_gpio_sim_line(item); 1214 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1215 bool valid; 1216 int ret; 1217 1218 ret = kstrtobool(page, &valid); 1219 if (ret) 1220 return ret; 1221 1222 guard(mutex)(&dev->lock); 1223 1224 line->valid = valid; 1225 1226 return count; 1227 } 1228 1229 CONFIGFS_ATTR(gpio_sim_line_config_, valid); 1230 1231 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1232 &gpio_sim_line_config_attr_name, 1233 &gpio_sim_line_config_attr_valid, 1234 NULL 1235 }; 1236 1237 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1238 char *page) 1239 { 1240 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1241 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1242 1243 guard(mutex)(&dev->lock); 1244 1245 return sysfs_emit(page, "%s\n", hog->name ?: ""); 1246 } 1247 1248 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1249 const char *page, size_t count) 1250 { 1251 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1252 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1253 char *trimmed; 1254 1255 guard(mutex)(&dev->lock); 1256 1257 if (gpio_sim_device_is_live(dev)) 1258 return -EBUSY; 1259 1260 trimmed = gpio_sim_strdup_trimmed(page, count); 1261 if (!trimmed) 1262 return -ENOMEM; 1263 1264 kfree(hog->name); 1265 hog->name = trimmed; 1266 1267 return count; 1268 } 1269 1270 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1271 1272 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1273 char *page) 1274 { 1275 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1276 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1277 char *repr; 1278 int dir; 1279 1280 scoped_guard(mutex, &dev->lock) 1281 dir = hog->dir; 1282 1283 switch (dir) { 1284 case GPIOD_IN: 1285 repr = "input"; 1286 break; 1287 case GPIOD_OUT_HIGH: 1288 repr = "output-high"; 1289 break; 1290 case GPIOD_OUT_LOW: 1291 repr = "output-low"; 1292 break; 1293 default: 1294 /* This would be a programmer bug. */ 1295 WARN(1, "Unexpected hog direction value: %d", dir); 1296 return -EINVAL; 1297 } 1298 1299 return sysfs_emit(page, "%s\n", repr); 1300 } 1301 1302 static ssize_t 1303 gpio_sim_hog_config_direction_store(struct config_item *item, 1304 const char *page, size_t count) 1305 { 1306 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1307 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1308 int dir; 1309 1310 guard(mutex)(&dev->lock); 1311 1312 if (gpio_sim_device_is_live(dev)) 1313 return -EBUSY; 1314 1315 if (sysfs_streq(page, "input")) 1316 dir = GPIOD_IN; 1317 else if (sysfs_streq(page, "output-high")) 1318 dir = GPIOD_OUT_HIGH; 1319 else if (sysfs_streq(page, "output-low")) 1320 dir = GPIOD_OUT_LOW; 1321 else 1322 return -EINVAL; 1323 1324 hog->dir = dir; 1325 1326 return count; 1327 } 1328 1329 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1330 1331 static ssize_t gpio_sim_hog_config_active_low_show(struct config_item *item, 1332 char *page) 1333 { 1334 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1335 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1336 1337 guard(mutex)(&dev->lock); 1338 1339 return sysfs_emit(page, "%c\n", hog->active_low ? '1' : '0'); 1340 } 1341 1342 static ssize_t 1343 gpio_sim_hog_config_active_low_store(struct config_item *item, 1344 const char *page, size_t count) 1345 { 1346 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1347 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1348 bool active_low; 1349 int ret; 1350 1351 guard(mutex)(&dev->lock); 1352 1353 if (gpio_sim_device_is_live(dev)) 1354 return -EBUSY; 1355 1356 ret = kstrtobool(page, &active_low); 1357 if (ret) 1358 return ret; 1359 1360 hog->active_low = active_low; 1361 1362 return count; 1363 } 1364 1365 CONFIGFS_ATTR(gpio_sim_hog_config_, active_low); 1366 1367 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1368 &gpio_sim_hog_config_attr_name, 1369 &gpio_sim_hog_config_attr_direction, 1370 &gpio_sim_hog_config_attr_active_low, 1371 NULL 1372 }; 1373 1374 static void gpio_sim_hog_config_item_release(struct config_item *item) 1375 { 1376 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1377 struct gpio_sim_line *line = hog->parent; 1378 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1379 1380 scoped_guard(mutex, &dev->lock) 1381 line->hog = NULL; 1382 1383 kfree(hog->name); 1384 kfree(hog); 1385 } 1386 1387 static const struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1388 .release = gpio_sim_hog_config_item_release, 1389 }; 1390 1391 static const struct config_item_type gpio_sim_hog_config_type = { 1392 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1393 .ct_attrs = gpio_sim_hog_config_attrs, 1394 .ct_owner = THIS_MODULE, 1395 }; 1396 1397 static struct config_item * 1398 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1399 { 1400 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1401 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1402 struct gpio_sim_hog *hog; 1403 1404 if (strcmp(name, "hog") != 0) 1405 return ERR_PTR(-EINVAL); 1406 1407 guard(mutex)(&dev->lock); 1408 1409 hog = kzalloc_obj(*hog); 1410 if (!hog) 1411 return ERR_PTR(-ENOMEM); 1412 1413 config_item_init_type_name(&hog->item, name, 1414 &gpio_sim_hog_config_type); 1415 1416 hog->dir = GPIOD_IN; 1417 hog->name = NULL; 1418 hog->parent = line; 1419 line->hog = hog; 1420 1421 return &hog->item; 1422 } 1423 1424 static void gpio_sim_line_config_group_release(struct config_item *item) 1425 { 1426 struct gpio_sim_line *line = to_gpio_sim_line(item); 1427 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1428 1429 scoped_guard(mutex, &dev->lock) 1430 list_del(&line->siblings); 1431 1432 kfree(line->name); 1433 kfree(line); 1434 } 1435 1436 static const struct configfs_item_operations gpio_sim_line_config_item_ops = { 1437 .release = gpio_sim_line_config_group_release, 1438 }; 1439 1440 static const struct configfs_group_operations gpio_sim_line_config_group_ops = { 1441 .make_item = gpio_sim_line_config_make_hog_item, 1442 }; 1443 1444 static const struct config_item_type gpio_sim_line_config_type = { 1445 .ct_item_ops = &gpio_sim_line_config_item_ops, 1446 .ct_group_ops = &gpio_sim_line_config_group_ops, 1447 .ct_attrs = gpio_sim_line_config_attrs, 1448 .ct_owner = THIS_MODULE, 1449 }; 1450 1451 static struct config_group * 1452 gpio_sim_bank_config_make_line_group(struct config_group *group, 1453 const char *name) 1454 { 1455 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1456 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1457 struct gpio_sim_line *line; 1458 unsigned int offset; 1459 int ret, nchar; 1460 1461 ret = sscanf(name, "line%u%n", &offset, &nchar); 1462 if (ret != 1 || nchar != strlen(name)) 1463 return ERR_PTR(-EINVAL); 1464 1465 guard(mutex)(&dev->lock); 1466 1467 if (gpio_sim_device_is_live(dev)) 1468 return ERR_PTR(-EBUSY); 1469 1470 line = kzalloc_obj(*line); 1471 if (!line) 1472 return ERR_PTR(-ENOMEM); 1473 1474 config_group_init_type_name(&line->group, name, 1475 &gpio_sim_line_config_type); 1476 1477 line->parent = bank; 1478 line->offset = offset; 1479 line->valid = true; 1480 list_add_tail(&line->siblings, &bank->line_list); 1481 1482 return &line->group; 1483 } 1484 1485 static void gpio_sim_bank_config_group_release(struct config_item *item) 1486 { 1487 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1488 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1489 1490 scoped_guard(mutex, &dev->lock) 1491 list_del(&bank->siblings); 1492 1493 kfree(bank->label); 1494 kfree(bank); 1495 } 1496 1497 static const struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1498 .release = gpio_sim_bank_config_group_release, 1499 }; 1500 1501 static const struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1502 .make_group = gpio_sim_bank_config_make_line_group, 1503 }; 1504 1505 static const struct config_item_type gpio_sim_bank_config_group_type = { 1506 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1507 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1508 .ct_attrs = gpio_sim_bank_config_attrs, 1509 .ct_owner = THIS_MODULE, 1510 }; 1511 1512 static struct config_group * 1513 gpio_sim_device_config_make_bank_group(struct config_group *group, 1514 const char *name) 1515 { 1516 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1517 struct gpio_sim_bank *bank; 1518 1519 guard(mutex)(&dev->lock); 1520 1521 if (gpio_sim_device_is_live(dev)) 1522 return ERR_PTR(-EBUSY); 1523 1524 bank = kzalloc_obj(*bank); 1525 if (!bank) 1526 return ERR_PTR(-ENOMEM); 1527 1528 config_group_init_type_name(&bank->group, name, 1529 &gpio_sim_bank_config_group_type); 1530 bank->num_lines = 1; 1531 bank->parent = dev; 1532 INIT_LIST_HEAD(&bank->line_list); 1533 list_add_tail(&bank->siblings, &dev->bank_list); 1534 1535 return &bank->group; 1536 } 1537 1538 static void gpio_sim_device_config_group_release(struct config_item *item) 1539 { 1540 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1541 1542 scoped_guard(mutex, &dev->lock) { 1543 if (gpio_sim_device_is_live(dev)) 1544 gpio_sim_device_deactivate(dev); 1545 } 1546 1547 mutex_destroy(&dev->lock); 1548 ida_free(&gpio_sim_ida, dev->id); 1549 kfree(dev); 1550 } 1551 1552 static const struct configfs_item_operations gpio_sim_device_config_item_ops = { 1553 .release = gpio_sim_device_config_group_release, 1554 }; 1555 1556 static const struct configfs_group_operations gpio_sim_device_config_group_ops = { 1557 .make_group = gpio_sim_device_config_make_bank_group, 1558 }; 1559 1560 static const struct config_item_type gpio_sim_device_config_group_type = { 1561 .ct_item_ops = &gpio_sim_device_config_item_ops, 1562 .ct_group_ops = &gpio_sim_device_config_group_ops, 1563 .ct_attrs = gpio_sim_device_config_attrs, 1564 .ct_owner = THIS_MODULE, 1565 }; 1566 1567 static struct config_group * 1568 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1569 { 1570 int id; 1571 1572 struct gpio_sim_device *dev __free(kfree) = kzalloc_obj(*dev); 1573 if (!dev) 1574 return ERR_PTR(-ENOMEM); 1575 1576 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1577 if (id < 0) 1578 return ERR_PTR(id); 1579 1580 config_group_init_type_name(&dev->group, name, 1581 &gpio_sim_device_config_group_type); 1582 dev->id = id; 1583 mutex_init(&dev->lock); 1584 INIT_LIST_HEAD(&dev->bank_list); 1585 1586 return &no_free_ptr(dev)->group; 1587 } 1588 1589 static const struct configfs_group_operations gpio_sim_config_group_ops = { 1590 .make_group = gpio_sim_config_make_device_group, 1591 }; 1592 1593 static const struct config_item_type gpio_sim_config_type = { 1594 .ct_group_ops = &gpio_sim_config_group_ops, 1595 .ct_owner = THIS_MODULE, 1596 }; 1597 1598 static struct configfs_subsystem gpio_sim_config_subsys = { 1599 .su_group = { 1600 .cg_item = { 1601 .ci_namebuf = "gpio-sim", 1602 .ci_type = &gpio_sim_config_type, 1603 }, 1604 }, 1605 }; 1606 1607 static int __init gpio_sim_init(void) 1608 { 1609 int ret; 1610 1611 ret = platform_driver_register(&gpio_sim_driver); 1612 if (ret) { 1613 pr_err("Error %d while registering the platform driver\n", ret); 1614 return ret; 1615 } 1616 1617 config_group_init(&gpio_sim_config_subsys.su_group); 1618 mutex_init(&gpio_sim_config_subsys.su_mutex); 1619 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1620 if (ret) { 1621 pr_err("Error %d while registering the configfs subsystem %s\n", 1622 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1623 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1624 platform_driver_unregister(&gpio_sim_driver); 1625 return ret; 1626 } 1627 1628 return 0; 1629 } 1630 module_init(gpio_sim_init); 1631 1632 static void __exit gpio_sim_exit(void) 1633 { 1634 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1635 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1636 platform_driver_unregister(&gpio_sim_driver); 1637 } 1638 module_exit(gpio_sim_exit); 1639 1640 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); 1641 MODULE_DESCRIPTION("GPIO Simulator Module"); 1642 MODULE_LICENSE("GPL"); 1643