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 = kcalloc(line_names_size, sizeof(*line_names), 794 GFP_KERNEL); 795 if (!line_names) 796 return ERR_PTR(-ENOMEM); 797 798 gpio_sim_set_line_names(bank, line_names); 799 800 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 801 "gpio-line-names", 802 line_names, line_names_size); 803 } 804 805 ranges_size = gpio_sim_get_reserved_ranges_size(bank); 806 if (ranges_size) { 807 ranges = kcalloc(ranges_size, sizeof(u32), GFP_KERNEL); 808 if (!ranges) 809 return ERR_PTR(-ENOMEM); 810 811 gpio_sim_set_reserved_ranges(bank, ranges); 812 813 properties[prop_idx++] = PROPERTY_ENTRY_U32_ARRAY_LEN( 814 "gpio-reserved-ranges", 815 ranges, ranges_size); 816 } 817 818 return fwnode_create_software_node(properties, parent); 819 } 820 821 static int gpio_sim_bank_add_hogs(struct gpio_sim_bank *bank) 822 { 823 struct property_entry properties[GPIO_SIM_HOG_PROP_MAX]; 824 struct fwnode_handle *swnode; 825 struct gpio_sim_line *line; 826 struct gpio_sim_hog *hog; 827 unsigned int idx; 828 u32 gpios[2]; 829 830 list_for_each_entry(line, &bank->line_list, siblings) { 831 if (!line->hog) 832 continue; 833 834 hog = line->hog; 835 836 gpios[0] = line->offset; 837 gpios[1] = hog->active_low ? 1 : 0; 838 839 memset(properties, 0, sizeof(properties)); 840 841 idx = 0; 842 properties[idx++] = PROPERTY_ENTRY_BOOL("gpio-hog"); 843 properties[idx++] = PROPERTY_ENTRY_U32_ARRAY("gpios", gpios); 844 properties[idx++] = PROPERTY_ENTRY_STRING("line-name", hog->name); 845 846 switch (hog->dir) { 847 case GPIOD_IN: 848 properties[idx++] = PROPERTY_ENTRY_BOOL("input"); 849 break; 850 case GPIOD_OUT_HIGH: 851 properties[idx++] = PROPERTY_ENTRY_BOOL("output-high"); 852 break; 853 case GPIOD_OUT_LOW: 854 properties[idx++] = PROPERTY_ENTRY_BOOL("output-low"); 855 break; 856 default: 857 /* Would have been validated at configfs store. */ 858 WARN(1, "Unexpected hog direction value: %d", hog->dir); 859 return -EINVAL; 860 } 861 862 swnode = fwnode_create_software_node(properties, bank->swnode); 863 if (IS_ERR(swnode)) 864 return PTR_ERR(swnode); 865 } 866 867 return 0; 868 } 869 870 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 871 { 872 struct fwnode_handle *child; 873 874 fwnode_for_each_child_node(swnode, child) 875 gpio_sim_remove_swnode_recursive(child); 876 877 fwnode_remove_software_node(swnode); 878 } 879 880 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 881 { 882 struct gpio_sim_bank *this, *pos; 883 884 list_for_each_entry(this, &dev->bank_list, siblings) { 885 list_for_each_entry(pos, &dev->bank_list, siblings) { 886 if (this == pos || (!this->label || !pos->label)) 887 continue; 888 889 if (strcmp(this->label, pos->label) == 0) 890 return true; 891 } 892 } 893 894 return false; 895 } 896 897 static int gpio_sim_device_activate(struct gpio_sim_device *dev) 898 { 899 struct platform_device_info pdevinfo; 900 struct platform_device *pdev; 901 struct fwnode_handle *swnode; 902 struct gpio_sim_bank *bank; 903 int ret = 0; 904 905 lockdep_assert_held(&dev->lock); 906 907 if (list_empty(&dev->bank_list)) 908 return -ENODATA; 909 910 /* 911 * Non-unique GPIO device labels are a corner-case we don't support 912 * as it would interfere with machine hogging mechanism and has little 913 * use in real life. 914 */ 915 if (gpio_sim_bank_labels_non_unique(dev)) 916 return -EINVAL; 917 918 memset(&pdevinfo, 0, sizeof(pdevinfo)); 919 920 swnode = fwnode_create_software_node(NULL, NULL); 921 if (IS_ERR(swnode)) 922 return PTR_ERR(swnode); 923 924 list_for_each_entry(bank, &dev->bank_list, siblings) { 925 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 926 if (IS_ERR(bank->swnode)) { 927 ret = PTR_ERR(bank->swnode); 928 goto err_remove_swnode; 929 } 930 931 ret = gpio_sim_bank_add_hogs(bank); 932 if (ret) 933 goto err_remove_swnode; 934 } 935 936 pdevinfo.name = "gpio-sim"; 937 pdevinfo.fwnode = swnode; 938 pdevinfo.id = dev->id; 939 940 pdev = platform_device_register_full(&pdevinfo); 941 if (IS_ERR(pdev)) { 942 ret = PTR_ERR(pdev); 943 goto err_remove_swnode; 944 } 945 946 wait_for_device_probe(); 947 948 scoped_guard(device, &pdev->dev) { 949 if (!device_is_bound(&pdev->dev)) { 950 ret = -ENXIO; 951 goto err_unregister_pdev; 952 } 953 } 954 955 dev->pdev = pdev; 956 return 0; 957 958 err_unregister_pdev: 959 platform_device_unregister(pdev); 960 err_remove_swnode: 961 gpio_sim_remove_swnode_recursive(swnode); 962 963 return ret; 964 } 965 966 static void gpio_sim_device_deactivate(struct gpio_sim_device *dev) 967 { 968 struct fwnode_handle *swnode; 969 970 lockdep_assert_held(&dev->lock); 971 972 swnode = dev_fwnode(&dev->pdev->dev); 973 platform_device_unregister(dev->pdev); 974 dev->pdev = NULL; 975 gpio_sim_remove_swnode_recursive(swnode); 976 } 977 978 static void 979 gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock) 980 { 981 struct configfs_subsystem *subsys = dev->group.cg_subsys; 982 struct gpio_sim_bank *bank; 983 struct gpio_sim_line *line; 984 struct config_item *item; 985 986 /* 987 * The device only needs to depend on leaf entries. This is 988 * sufficient to lock up all the configfs entries that the 989 * instantiated, alive device depends on. 990 */ 991 list_for_each_entry(bank, &dev->bank_list, siblings) { 992 list_for_each_entry(line, &bank->line_list, siblings) { 993 item = line->hog ? &line->hog->item 994 : &line->group.cg_item; 995 996 if (lock) 997 WARN_ON(configfs_depend_item_unlocked(subsys, 998 item)); 999 else 1000 configfs_undepend_item_unlocked(item); 1001 } 1002 } 1003 } 1004 1005 static ssize_t 1006 gpio_sim_device_config_live_store(struct config_item *item, 1007 const char *page, size_t count) 1008 { 1009 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1010 bool live; 1011 int ret; 1012 1013 ret = kstrtobool(page, &live); 1014 if (ret) 1015 return ret; 1016 1017 if (live) 1018 gpio_sim_device_lockup_configfs(dev, true); 1019 1020 scoped_guard(mutex, &dev->lock) { 1021 if (live == gpio_sim_device_is_live(dev)) 1022 ret = -EPERM; 1023 else if (live) 1024 ret = gpio_sim_device_activate(dev); 1025 else 1026 gpio_sim_device_deactivate(dev); 1027 } 1028 1029 /* 1030 * Undepend is required only if device disablement (live == 0) 1031 * succeeds or if device enablement (live == 1) fails. 1032 */ 1033 if (live == !!ret) 1034 gpio_sim_device_lockup_configfs(dev, false); 1035 1036 return ret ?: count; 1037 } 1038 1039 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1040 1041 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1042 &gpio_sim_device_config_attr_dev_name, 1043 &gpio_sim_device_config_attr_live, 1044 NULL 1045 }; 1046 1047 struct gpio_sim_chip_name_ctx { 1048 struct fwnode_handle *swnode; 1049 char *page; 1050 }; 1051 1052 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1053 { 1054 struct gpio_sim_chip_name_ctx *ctx = data; 1055 1056 /* This would be the sysfs device exported in /sys/class/gpio. */ 1057 if (dev->class) 1058 return 0; 1059 1060 if (device_match_fwnode(dev, ctx->swnode)) 1061 return sysfs_emit(ctx->page, "%s\n", dev_name(dev)); 1062 1063 return 0; 1064 } 1065 1066 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1067 char *page) 1068 { 1069 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1070 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1071 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1072 1073 guard(mutex)(&dev->lock); 1074 1075 if (gpio_sim_device_is_live(dev)) 1076 return device_for_each_child(&dev->pdev->dev, &ctx, 1077 gpio_sim_emit_chip_name); 1078 1079 return sysfs_emit(page, "none\n"); 1080 } 1081 1082 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1083 1084 static ssize_t 1085 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1086 { 1087 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1088 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1089 1090 guard(mutex)(&dev->lock); 1091 1092 return sysfs_emit(page, "%s\n", bank->label ?: ""); 1093 } 1094 1095 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1096 const char *page, size_t count) 1097 { 1098 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1099 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1100 char *trimmed; 1101 1102 guard(mutex)(&dev->lock); 1103 1104 if (gpio_sim_device_is_live(dev)) 1105 return -EBUSY; 1106 1107 trimmed = gpio_sim_strdup_trimmed(page, count); 1108 if (!trimmed) 1109 return -ENOMEM; 1110 1111 kfree(bank->label); 1112 bank->label = trimmed; 1113 1114 return count; 1115 } 1116 1117 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1118 1119 static ssize_t 1120 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1121 { 1122 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1123 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1124 1125 guard(mutex)(&dev->lock); 1126 1127 return sysfs_emit(page, "%u\n", bank->num_lines); 1128 } 1129 1130 static ssize_t 1131 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1132 const char *page, size_t count) 1133 { 1134 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1135 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1136 unsigned int num_lines; 1137 int ret; 1138 1139 ret = kstrtouint(page, 0, &num_lines); 1140 if (ret) 1141 return ret; 1142 1143 if (num_lines == 0) 1144 return -EINVAL; 1145 1146 guard(mutex)(&dev->lock); 1147 1148 if (gpio_sim_device_is_live(dev)) 1149 return -EBUSY; 1150 1151 bank->num_lines = num_lines; 1152 1153 return count; 1154 } 1155 1156 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1157 1158 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1159 &gpio_sim_bank_config_attr_chip_name, 1160 &gpio_sim_bank_config_attr_label, 1161 &gpio_sim_bank_config_attr_num_lines, 1162 NULL 1163 }; 1164 1165 static ssize_t 1166 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1167 { 1168 struct gpio_sim_line *line = to_gpio_sim_line(item); 1169 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1170 1171 guard(mutex)(&dev->lock); 1172 1173 return sysfs_emit(page, "%s\n", line->name ?: ""); 1174 } 1175 1176 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1177 const char *page, size_t count) 1178 { 1179 struct gpio_sim_line *line = to_gpio_sim_line(item); 1180 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1181 char *trimmed; 1182 1183 guard(mutex)(&dev->lock); 1184 1185 if (gpio_sim_device_is_live(dev)) 1186 return -EBUSY; 1187 1188 trimmed = gpio_sim_strdup_trimmed(page, count); 1189 if (!trimmed) 1190 return -ENOMEM; 1191 1192 kfree(line->name); 1193 line->name = trimmed; 1194 1195 return count; 1196 } 1197 1198 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1199 1200 static ssize_t 1201 gpio_sim_line_config_valid_show(struct config_item *item, char *page) 1202 { 1203 struct gpio_sim_line *line = to_gpio_sim_line(item); 1204 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1205 1206 guard(mutex)(&dev->lock); 1207 1208 return sysfs_emit(page, "%c\n", line->valid ? '1' : '0'); 1209 } 1210 1211 static ssize_t gpio_sim_line_config_valid_store(struct config_item *item, 1212 const char *page, size_t count) 1213 { 1214 struct gpio_sim_line *line = to_gpio_sim_line(item); 1215 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1216 bool valid; 1217 int ret; 1218 1219 ret = kstrtobool(page, &valid); 1220 if (ret) 1221 return ret; 1222 1223 guard(mutex)(&dev->lock); 1224 1225 line->valid = valid; 1226 1227 return count; 1228 } 1229 1230 CONFIGFS_ATTR(gpio_sim_line_config_, valid); 1231 1232 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1233 &gpio_sim_line_config_attr_name, 1234 &gpio_sim_line_config_attr_valid, 1235 NULL 1236 }; 1237 1238 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1239 char *page) 1240 { 1241 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1242 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1243 1244 guard(mutex)(&dev->lock); 1245 1246 return sysfs_emit(page, "%s\n", hog->name ?: ""); 1247 } 1248 1249 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1250 const char *page, size_t count) 1251 { 1252 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1253 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1254 char *trimmed; 1255 1256 guard(mutex)(&dev->lock); 1257 1258 if (gpio_sim_device_is_live(dev)) 1259 return -EBUSY; 1260 1261 trimmed = gpio_sim_strdup_trimmed(page, count); 1262 if (!trimmed) 1263 return -ENOMEM; 1264 1265 kfree(hog->name); 1266 hog->name = trimmed; 1267 1268 return count; 1269 } 1270 1271 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1272 1273 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1274 char *page) 1275 { 1276 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1277 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1278 char *repr; 1279 int dir; 1280 1281 scoped_guard(mutex, &dev->lock) 1282 dir = hog->dir; 1283 1284 switch (dir) { 1285 case GPIOD_IN: 1286 repr = "input"; 1287 break; 1288 case GPIOD_OUT_HIGH: 1289 repr = "output-high"; 1290 break; 1291 case GPIOD_OUT_LOW: 1292 repr = "output-low"; 1293 break; 1294 default: 1295 /* This would be a programmer bug. */ 1296 WARN(1, "Unexpected hog direction value: %d", dir); 1297 return -EINVAL; 1298 } 1299 1300 return sysfs_emit(page, "%s\n", repr); 1301 } 1302 1303 static ssize_t 1304 gpio_sim_hog_config_direction_store(struct config_item *item, 1305 const char *page, size_t count) 1306 { 1307 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1308 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1309 int dir; 1310 1311 guard(mutex)(&dev->lock); 1312 1313 if (gpio_sim_device_is_live(dev)) 1314 return -EBUSY; 1315 1316 if (sysfs_streq(page, "input")) 1317 dir = GPIOD_IN; 1318 else if (sysfs_streq(page, "output-high")) 1319 dir = GPIOD_OUT_HIGH; 1320 else if (sysfs_streq(page, "output-low")) 1321 dir = GPIOD_OUT_LOW; 1322 else 1323 return -EINVAL; 1324 1325 hog->dir = dir; 1326 1327 return count; 1328 } 1329 1330 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1331 1332 static ssize_t gpio_sim_hog_config_active_low_show(struct config_item *item, 1333 char *page) 1334 { 1335 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1336 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1337 1338 guard(mutex)(&dev->lock); 1339 1340 return sysfs_emit(page, "%c\n", hog->active_low ? '1' : '0'); 1341 } 1342 1343 static ssize_t 1344 gpio_sim_hog_config_active_low_store(struct config_item *item, 1345 const char *page, size_t count) 1346 { 1347 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1348 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1349 bool active_low; 1350 int ret; 1351 1352 guard(mutex)(&dev->lock); 1353 1354 if (gpio_sim_device_is_live(dev)) 1355 return -EBUSY; 1356 1357 ret = kstrtobool(page, &active_low); 1358 if (ret) 1359 return ret; 1360 1361 hog->active_low = active_low; 1362 1363 return count; 1364 } 1365 1366 CONFIGFS_ATTR(gpio_sim_hog_config_, active_low); 1367 1368 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1369 &gpio_sim_hog_config_attr_name, 1370 &gpio_sim_hog_config_attr_direction, 1371 &gpio_sim_hog_config_attr_active_low, 1372 NULL 1373 }; 1374 1375 static void gpio_sim_hog_config_item_release(struct config_item *item) 1376 { 1377 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1378 struct gpio_sim_line *line = hog->parent; 1379 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1380 1381 scoped_guard(mutex, &dev->lock) 1382 line->hog = NULL; 1383 1384 kfree(hog->name); 1385 kfree(hog); 1386 } 1387 1388 static const struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1389 .release = gpio_sim_hog_config_item_release, 1390 }; 1391 1392 static const struct config_item_type gpio_sim_hog_config_type = { 1393 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1394 .ct_attrs = gpio_sim_hog_config_attrs, 1395 .ct_owner = THIS_MODULE, 1396 }; 1397 1398 static struct config_item * 1399 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1400 { 1401 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1402 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1403 struct gpio_sim_hog *hog; 1404 1405 if (strcmp(name, "hog") != 0) 1406 return ERR_PTR(-EINVAL); 1407 1408 guard(mutex)(&dev->lock); 1409 1410 hog = kzalloc_obj(*hog); 1411 if (!hog) 1412 return ERR_PTR(-ENOMEM); 1413 1414 config_item_init_type_name(&hog->item, name, 1415 &gpio_sim_hog_config_type); 1416 1417 hog->dir = GPIOD_IN; 1418 hog->name = NULL; 1419 hog->parent = line; 1420 line->hog = hog; 1421 1422 return &hog->item; 1423 } 1424 1425 static void gpio_sim_line_config_group_release(struct config_item *item) 1426 { 1427 struct gpio_sim_line *line = to_gpio_sim_line(item); 1428 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1429 1430 scoped_guard(mutex, &dev->lock) 1431 list_del(&line->siblings); 1432 1433 kfree(line->name); 1434 kfree(line); 1435 } 1436 1437 static const struct configfs_item_operations gpio_sim_line_config_item_ops = { 1438 .release = gpio_sim_line_config_group_release, 1439 }; 1440 1441 static const struct configfs_group_operations gpio_sim_line_config_group_ops = { 1442 .make_item = gpio_sim_line_config_make_hog_item, 1443 }; 1444 1445 static const struct config_item_type gpio_sim_line_config_type = { 1446 .ct_item_ops = &gpio_sim_line_config_item_ops, 1447 .ct_group_ops = &gpio_sim_line_config_group_ops, 1448 .ct_attrs = gpio_sim_line_config_attrs, 1449 .ct_owner = THIS_MODULE, 1450 }; 1451 1452 static struct config_group * 1453 gpio_sim_bank_config_make_line_group(struct config_group *group, 1454 const char *name) 1455 { 1456 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1457 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1458 struct gpio_sim_line *line; 1459 unsigned int offset; 1460 int ret, nchar; 1461 1462 ret = sscanf(name, "line%u%n", &offset, &nchar); 1463 if (ret != 1 || nchar != strlen(name)) 1464 return ERR_PTR(-EINVAL); 1465 1466 guard(mutex)(&dev->lock); 1467 1468 if (gpio_sim_device_is_live(dev)) 1469 return ERR_PTR(-EBUSY); 1470 1471 line = kzalloc_obj(*line); 1472 if (!line) 1473 return ERR_PTR(-ENOMEM); 1474 1475 config_group_init_type_name(&line->group, name, 1476 &gpio_sim_line_config_type); 1477 1478 line->parent = bank; 1479 line->offset = offset; 1480 line->valid = true; 1481 list_add_tail(&line->siblings, &bank->line_list); 1482 1483 return &line->group; 1484 } 1485 1486 static void gpio_sim_bank_config_group_release(struct config_item *item) 1487 { 1488 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1489 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1490 1491 scoped_guard(mutex, &dev->lock) 1492 list_del(&bank->siblings); 1493 1494 kfree(bank->label); 1495 kfree(bank); 1496 } 1497 1498 static const struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1499 .release = gpio_sim_bank_config_group_release, 1500 }; 1501 1502 static const struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1503 .make_group = gpio_sim_bank_config_make_line_group, 1504 }; 1505 1506 static const struct config_item_type gpio_sim_bank_config_group_type = { 1507 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1508 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1509 .ct_attrs = gpio_sim_bank_config_attrs, 1510 .ct_owner = THIS_MODULE, 1511 }; 1512 1513 static struct config_group * 1514 gpio_sim_device_config_make_bank_group(struct config_group *group, 1515 const char *name) 1516 { 1517 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1518 struct gpio_sim_bank *bank; 1519 1520 guard(mutex)(&dev->lock); 1521 1522 if (gpio_sim_device_is_live(dev)) 1523 return ERR_PTR(-EBUSY); 1524 1525 bank = kzalloc_obj(*bank); 1526 if (!bank) 1527 return ERR_PTR(-ENOMEM); 1528 1529 config_group_init_type_name(&bank->group, name, 1530 &gpio_sim_bank_config_group_type); 1531 bank->num_lines = 1; 1532 bank->parent = dev; 1533 INIT_LIST_HEAD(&bank->line_list); 1534 list_add_tail(&bank->siblings, &dev->bank_list); 1535 1536 return &bank->group; 1537 } 1538 1539 static void gpio_sim_device_config_group_release(struct config_item *item) 1540 { 1541 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1542 1543 scoped_guard(mutex, &dev->lock) { 1544 if (gpio_sim_device_is_live(dev)) 1545 gpio_sim_device_deactivate(dev); 1546 } 1547 1548 mutex_destroy(&dev->lock); 1549 ida_free(&gpio_sim_ida, dev->id); 1550 kfree(dev); 1551 } 1552 1553 static const struct configfs_item_operations gpio_sim_device_config_item_ops = { 1554 .release = gpio_sim_device_config_group_release, 1555 }; 1556 1557 static const struct configfs_group_operations gpio_sim_device_config_group_ops = { 1558 .make_group = gpio_sim_device_config_make_bank_group, 1559 }; 1560 1561 static const struct config_item_type gpio_sim_device_config_group_type = { 1562 .ct_item_ops = &gpio_sim_device_config_item_ops, 1563 .ct_group_ops = &gpio_sim_device_config_group_ops, 1564 .ct_attrs = gpio_sim_device_config_attrs, 1565 .ct_owner = THIS_MODULE, 1566 }; 1567 1568 static struct config_group * 1569 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1570 { 1571 int id; 1572 1573 struct gpio_sim_device *dev __free(kfree) = kzalloc_obj(*dev); 1574 if (!dev) 1575 return ERR_PTR(-ENOMEM); 1576 1577 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1578 if (id < 0) 1579 return ERR_PTR(id); 1580 1581 config_group_init_type_name(&dev->group, name, 1582 &gpio_sim_device_config_group_type); 1583 dev->id = id; 1584 mutex_init(&dev->lock); 1585 INIT_LIST_HEAD(&dev->bank_list); 1586 1587 return &no_free_ptr(dev)->group; 1588 } 1589 1590 static const struct configfs_group_operations gpio_sim_config_group_ops = { 1591 .make_group = gpio_sim_config_make_device_group, 1592 }; 1593 1594 static const struct config_item_type gpio_sim_config_type = { 1595 .ct_group_ops = &gpio_sim_config_group_ops, 1596 .ct_owner = THIS_MODULE, 1597 }; 1598 1599 static struct configfs_subsystem gpio_sim_config_subsys = { 1600 .su_group = { 1601 .cg_item = { 1602 .ci_namebuf = "gpio-sim", 1603 .ci_type = &gpio_sim_config_type, 1604 }, 1605 }, 1606 }; 1607 1608 static int __init gpio_sim_init(void) 1609 { 1610 int ret; 1611 1612 ret = platform_driver_register(&gpio_sim_driver); 1613 if (ret) { 1614 pr_err("Error %d while registering the platform driver\n", ret); 1615 return ret; 1616 } 1617 1618 config_group_init(&gpio_sim_config_subsys.su_group); 1619 mutex_init(&gpio_sim_config_subsys.su_mutex); 1620 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1621 if (ret) { 1622 pr_err("Error %d while registering the configfs subsystem %s\n", 1623 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1624 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1625 platform_driver_unregister(&gpio_sim_driver); 1626 return ret; 1627 } 1628 1629 return 0; 1630 } 1631 module_init(gpio_sim_init); 1632 1633 static void __exit gpio_sim_exit(void) 1634 { 1635 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1636 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1637 platform_driver_unregister(&gpio_sim_driver); 1638 } 1639 module_exit(gpio_sim_exit); 1640 1641 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); 1642 MODULE_DESCRIPTION("GPIO Simulator Module"); 1643 MODULE_LICENSE("GPL"); 1644