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/mod_devicetable.h> 27 #include <linux/module.h> 28 #include <linux/mutex.h> 29 #include <linux/notifier.h> 30 #include <linux/platform_device.h> 31 #include <linux/property.h> 32 #include <linux/seq_file.h> 33 #include <linux/slab.h> 34 #include <linux/string.h> 35 #include <linux/string_helpers.h> 36 #include <linux/sysfs.h> 37 #include <linux/types.h> 38 39 #define GPIO_SIM_NGPIO_MAX 1024 40 #define GPIO_SIM_PROP_MAX 5 /* Max 4 properties + sentinel. */ 41 #define GPIO_SIM_HOG_PROP_MAX 5 42 #define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */ 43 44 static DEFINE_IDA(gpio_sim_ida); 45 46 struct gpio_sim_chip { 47 struct gpio_chip gc; 48 struct device *dev; 49 unsigned long *request_map; 50 unsigned long *direction_map; 51 unsigned long *value_map; 52 unsigned long *pull_map; 53 struct irq_domain *irq_sim; 54 struct mutex lock; 55 const struct attribute_group **attr_groups; 56 }; 57 58 struct gpio_sim_attribute { 59 struct device_attribute dev_attr; 60 unsigned int offset; 61 }; 62 63 static struct gpio_sim_attribute * 64 to_gpio_sim_attr(struct device_attribute *dev_attr) 65 { 66 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 67 } 68 69 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 70 unsigned int offset, int value) 71 { 72 int irq, irq_type, ret; 73 74 guard(mutex)(&chip->lock); 75 76 if (test_bit(offset, chip->request_map) && 77 test_bit(offset, chip->direction_map)) { 78 if (value == !!test_bit(offset, chip->value_map)) 79 goto set_pull; 80 81 /* 82 * This is fine - it just means, nobody is listening 83 * for interrupts on this line, otherwise 84 * irq_create_mapping() would have been called from 85 * the to_irq() callback. 86 */ 87 irq = irq_find_mapping(chip->irq_sim, offset); 88 if (!irq) 89 goto set_value; 90 91 irq_type = irq_get_trigger_type(irq); 92 93 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) || 94 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) { 95 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 96 true); 97 if (ret) 98 goto set_pull; 99 } 100 } 101 102 set_value: 103 /* Change the value unless we're actively driving the line. */ 104 if (!test_bit(offset, chip->request_map) || 105 test_bit(offset, chip->direction_map)) 106 __assign_bit(offset, chip->value_map, value); 107 108 set_pull: 109 __assign_bit(offset, chip->pull_map, value); 110 return 0; 111 } 112 113 static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset) 114 { 115 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 116 117 guard(mutex)(&chip->lock); 118 119 return !!test_bit(offset, chip->value_map); 120 } 121 122 static int gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value) 123 { 124 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 125 126 scoped_guard(mutex, &chip->lock) 127 __assign_bit(offset, chip->value_map, value); 128 129 return 0; 130 } 131 132 static int gpio_sim_get_multiple(struct gpio_chip *gc, 133 unsigned long *mask, unsigned long *bits) 134 { 135 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 136 137 scoped_guard(mutex, &chip->lock) 138 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 139 140 return 0; 141 } 142 143 static int gpio_sim_set_multiple(struct gpio_chip *gc, 144 unsigned long *mask, unsigned long *bits) 145 { 146 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 147 148 scoped_guard(mutex, &chip->lock) 149 bitmap_replace(chip->value_map, chip->value_map, bits, mask, 150 gc->ngpio); 151 152 return 0; 153 } 154 155 static int gpio_sim_direction_output(struct gpio_chip *gc, 156 unsigned int offset, int value) 157 { 158 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 159 160 scoped_guard(mutex, &chip->lock) { 161 __clear_bit(offset, chip->direction_map); 162 __assign_bit(offset, chip->value_map, value); 163 } 164 165 return 0; 166 } 167 168 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 169 { 170 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 171 172 scoped_guard(mutex, &chip->lock) 173 __set_bit(offset, chip->direction_map); 174 175 return 0; 176 } 177 178 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 179 { 180 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 181 int direction; 182 183 scoped_guard(mutex, &chip->lock) 184 direction = !!test_bit(offset, chip->direction_map); 185 186 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; 187 } 188 189 static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset, 190 unsigned long config) 191 { 192 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 193 194 switch (pinconf_to_config_param(config)) { 195 case PIN_CONFIG_BIAS_PULL_UP: 196 return gpio_sim_apply_pull(chip, offset, 1); 197 case PIN_CONFIG_BIAS_PULL_DOWN: 198 return gpio_sim_apply_pull(chip, offset, 0); 199 default: 200 break; 201 } 202 203 return -ENOTSUPP; 204 } 205 206 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 207 { 208 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 209 210 return irq_create_mapping(chip->irq_sim, offset); 211 } 212 213 static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset) 214 { 215 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 216 217 scoped_guard(mutex, &chip->lock) 218 __set_bit(offset, chip->request_map); 219 220 return 0; 221 } 222 223 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 224 { 225 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 226 227 scoped_guard(mutex, &chip->lock) { 228 __assign_bit(offset, chip->value_map, 229 !!test_bit(offset, chip->pull_map)); 230 __clear_bit(offset, chip->request_map); 231 } 232 } 233 234 static int gpio_sim_irq_requested(struct irq_domain *domain, 235 irq_hw_number_t hwirq, void *data) 236 { 237 struct gpio_sim_chip *chip = data; 238 239 return gpiochip_lock_as_irq(&chip->gc, hwirq); 240 } 241 242 static void gpio_sim_irq_released(struct irq_domain *domain, 243 irq_hw_number_t hwirq, void *data) 244 { 245 struct gpio_sim_chip *chip = data; 246 247 gpiochip_unlock_as_irq(&chip->gc, hwirq); 248 } 249 250 static const struct irq_sim_ops gpio_sim_irq_sim_ops = { 251 .irq_sim_irq_requested = gpio_sim_irq_requested, 252 .irq_sim_irq_released = gpio_sim_irq_released, 253 }; 254 255 static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc) 256 { 257 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 258 const char *label; 259 int i; 260 261 guard(mutex)(&chip->lock); 262 263 for_each_hwgpio(gc, i, label) 264 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n", i, 265 label ?: "<unused>", 266 test_bit(i, chip->direction_map) ? "input" : 267 test_bit(i, chip->value_map) ? "output-high" : 268 "output-low", 269 test_bit(i, chip->pull_map) ? "pull-up" : 270 "pull-down"); 271 } 272 273 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 274 struct device_attribute *attr, char *buf) 275 { 276 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 277 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 278 int val; 279 280 scoped_guard(mutex, &chip->lock) 281 val = !!test_bit(line_attr->offset, chip->value_map); 282 283 return sysfs_emit(buf, "%d\n", val); 284 } 285 286 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 287 struct device_attribute *attr, 288 const char *buf, size_t count) 289 { 290 /* 291 * Not assigning this function will result in write() returning -EIO 292 * which is confusing. Return -EPERM explicitly. 293 */ 294 return -EPERM; 295 } 296 297 static const char *const gpio_sim_sysfs_pull_strings[] = { 298 [0] = "pull-down", 299 [1] = "pull-up", 300 }; 301 302 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 303 struct device_attribute *attr, 304 char *buf) 305 { 306 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 307 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 308 int pull; 309 310 scoped_guard(mutex, &chip->lock) 311 pull = !!test_bit(line_attr->offset, chip->pull_map); 312 313 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 314 } 315 316 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 317 struct device_attribute *attr, 318 const char *buf, size_t len) 319 { 320 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 321 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 322 int ret, pull; 323 324 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 325 if (pull < 0) 326 return pull; 327 328 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 329 if (ret) 330 return ret; 331 332 return len; 333 } 334 335 static void gpio_sim_put_device(void *data) 336 { 337 struct device *dev = data; 338 339 put_device(dev); 340 } 341 342 static void gpio_sim_dispose_mappings(void *data) 343 { 344 struct gpio_sim_chip *chip = data; 345 unsigned int i; 346 347 for (i = 0; i < chip->gc.ngpio; i++) 348 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 349 } 350 351 static void gpio_sim_sysfs_remove(void *data) 352 { 353 struct gpio_sim_chip *chip = data; 354 355 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups); 356 } 357 358 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 359 { 360 struct device_attribute *val_dev_attr, *pull_dev_attr; 361 struct gpio_sim_attribute *val_attr, *pull_attr; 362 unsigned int num_lines = chip->gc.ngpio; 363 struct device *dev = chip->gc.parent; 364 struct attribute_group *attr_group; 365 struct attribute **attrs; 366 int i, ret; 367 368 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 369 num_lines + 1, GFP_KERNEL); 370 if (!chip->attr_groups) 371 return -ENOMEM; 372 373 for (i = 0; i < num_lines; i++) { 374 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 375 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 376 GFP_KERNEL); 377 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 378 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 379 if (!attr_group || !attrs || !val_attr || !pull_attr) 380 return -ENOMEM; 381 382 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 383 "sim_gpio%u", i); 384 if (!attr_group->name) 385 return -ENOMEM; 386 387 val_attr->offset = pull_attr->offset = i; 388 389 val_dev_attr = &val_attr->dev_attr; 390 pull_dev_attr = &pull_attr->dev_attr; 391 392 sysfs_attr_init(&val_dev_attr->attr); 393 sysfs_attr_init(&pull_dev_attr->attr); 394 395 val_dev_attr->attr.name = "value"; 396 pull_dev_attr->attr.name = "pull"; 397 398 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 399 400 val_dev_attr->show = gpio_sim_sysfs_val_show; 401 val_dev_attr->store = gpio_sim_sysfs_val_store; 402 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 403 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 404 405 attrs[0] = &val_dev_attr->attr; 406 attrs[1] = &pull_dev_attr->attr; 407 408 attr_group->attrs = attrs; 409 chip->attr_groups[i] = attr_group; 410 } 411 412 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups); 413 if (ret) 414 return ret; 415 416 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 417 } 418 419 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 420 { 421 struct gpio_sim_chip *chip; 422 struct gpio_chip *gc; 423 const char *label; 424 u32 num_lines; 425 int ret; 426 427 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 428 if (ret) 429 return ret; 430 431 if (num_lines > GPIO_SIM_NGPIO_MAX) 432 return -ERANGE; 433 434 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 435 if (ret) { 436 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP", 437 dev_name(dev), swnode); 438 if (!label) 439 return -ENOMEM; 440 } 441 442 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 443 if (!chip) 444 return -ENOMEM; 445 446 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 447 if (!chip->request_map) 448 return -ENOMEM; 449 450 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 451 if (!chip->direction_map) 452 return -ENOMEM; 453 454 /* Default to input mode. */ 455 bitmap_fill(chip->direction_map, num_lines); 456 457 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 458 if (!chip->value_map) 459 return -ENOMEM; 460 461 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 462 if (!chip->pull_map) 463 return -ENOMEM; 464 465 chip->irq_sim = devm_irq_domain_create_sim_full(dev, swnode, num_lines, 466 &gpio_sim_irq_sim_ops, 467 chip); 468 if (IS_ERR(chip->irq_sim)) 469 return PTR_ERR(chip->irq_sim); 470 471 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 472 if (ret) 473 return ret; 474 475 ret = devm_mutex_init(dev, &chip->lock); 476 if (ret) 477 return ret; 478 479 gc = &chip->gc; 480 gc->base = -1; 481 gc->ngpio = num_lines; 482 gc->label = label; 483 gc->owner = THIS_MODULE; 484 gc->parent = dev; 485 gc->fwnode = swnode; 486 gc->get = gpio_sim_get; 487 gc->set = gpio_sim_set; 488 gc->get_multiple = gpio_sim_get_multiple; 489 gc->set_multiple = gpio_sim_set_multiple; 490 gc->direction_output = gpio_sim_direction_output; 491 gc->direction_input = gpio_sim_direction_input; 492 gc->get_direction = gpio_sim_get_direction; 493 gc->set_config = gpio_sim_set_config; 494 gc->to_irq = gpio_sim_to_irq; 495 gc->request = gpio_sim_request; 496 gc->free = gpio_sim_free; 497 gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show); 498 gc->can_sleep = true; 499 500 ret = devm_gpiochip_add_data(dev, gc, chip); 501 if (ret) 502 return ret; 503 504 chip->dev = device_find_child(dev, swnode, device_match_fwnode); 505 if (!chip->dev) 506 return -ENODEV; 507 508 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev); 509 if (ret) 510 return ret; 511 512 /* Used by sysfs callbacks. */ 513 dev_set_drvdata(chip->dev, chip); 514 515 return gpio_sim_setup_sysfs(chip); 516 } 517 518 static int gpio_sim_probe(struct platform_device *pdev) 519 { 520 struct device *dev = &pdev->dev; 521 int ret; 522 523 device_for_each_child_node_scoped(dev, swnode) { 524 ret = gpio_sim_add_bank(swnode, dev); 525 if (ret) 526 return ret; 527 } 528 529 return 0; 530 } 531 532 static const struct of_device_id gpio_sim_of_match[] = { 533 { .compatible = "gpio-simulator" }, 534 { } 535 }; 536 MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 537 538 static struct platform_driver gpio_sim_driver = { 539 .driver = { 540 .name = "gpio-sim", 541 .of_match_table = gpio_sim_of_match, 542 }, 543 .probe = gpio_sim_probe, 544 }; 545 546 struct gpio_sim_device { 547 struct platform_device *pdev; 548 struct config_group group; 549 550 int id; 551 552 /* 553 * Each configfs filesystem operation is protected with the subsystem 554 * mutex. Each separate attribute is protected with the buffer mutex. 555 * This structure however can be modified by callbacks of different 556 * attributes so we need another lock. 557 * 558 * We use this lock for protecting all data structures owned by this 559 * object too. 560 */ 561 struct mutex lock; 562 563 struct list_head bank_list; 564 }; 565 566 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 567 { 568 struct config_group *group = to_config_group(item); 569 570 return container_of(group, struct gpio_sim_device, group); 571 } 572 573 struct gpio_sim_bank { 574 struct config_group group; 575 576 /* 577 * We could have used the ci_parent field of the config_item but 578 * configfs is stupid and calls the item's release callback after 579 * already having cleared the parent pointer even though the parent 580 * is guaranteed to survive the child... 581 * 582 * So we need to store the pointer to the parent struct here. We can 583 * dereference it anywhere we need with no checks and no locking as 584 * it's guaranteed to survive the children and protected by configfs 585 * locks. 586 * 587 * Same for other structures. 588 */ 589 struct gpio_sim_device *parent; 590 struct list_head siblings; 591 592 char *label; 593 unsigned int num_lines; 594 595 struct list_head line_list; 596 597 struct fwnode_handle *swnode; 598 }; 599 600 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 601 { 602 struct config_group *group = to_config_group(item); 603 604 return container_of(group, struct gpio_sim_bank, group); 605 } 606 607 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 608 { 609 return bank->label && *bank->label; 610 } 611 612 static struct gpio_sim_device * 613 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 614 { 615 return bank->parent; 616 } 617 618 struct gpio_sim_hog; 619 620 struct gpio_sim_line { 621 struct config_group group; 622 623 struct gpio_sim_bank *parent; 624 struct list_head siblings; 625 626 unsigned int offset; 627 char *name; 628 bool valid; 629 630 /* There can only be one hog per line. */ 631 struct gpio_sim_hog *hog; 632 }; 633 634 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 635 { 636 struct config_group *group = to_config_group(item); 637 638 return container_of(group, struct gpio_sim_line, group); 639 } 640 641 static struct gpio_sim_device * 642 gpio_sim_line_get_device(struct gpio_sim_line *line) 643 { 644 struct gpio_sim_bank *bank = line->parent; 645 646 return gpio_sim_bank_get_device(bank); 647 } 648 649 struct gpio_sim_hog { 650 struct config_item item; 651 struct gpio_sim_line *parent; 652 653 char *name; 654 int dir; 655 bool active_low; 656 }; 657 658 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 659 { 660 return container_of(item, struct gpio_sim_hog, item); 661 } 662 663 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 664 { 665 struct gpio_sim_line *line = hog->parent; 666 667 return gpio_sim_line_get_device(line); 668 } 669 670 static bool gpio_sim_device_is_live(struct gpio_sim_device *dev) 671 { 672 lockdep_assert_held(&dev->lock); 673 674 return !!dev->pdev; 675 } 676 677 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 678 { 679 char *trimmed; 680 681 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 682 if (!trimmed) 683 return NULL; 684 685 return strim(trimmed); 686 } 687 688 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 689 char *page) 690 { 691 struct gpio_sim_device *dev = to_gpio_sim_device(item); 692 struct platform_device *pdev; 693 694 guard(mutex)(&dev->lock); 695 696 pdev = dev->pdev; 697 if (pdev) 698 return sprintf(page, "%s\n", dev_name(&pdev->dev)); 699 700 return sprintf(page, "gpio-sim.%d\n", dev->id); 701 } 702 703 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 704 705 static ssize_t 706 gpio_sim_device_config_live_show(struct config_item *item, char *page) 707 { 708 struct gpio_sim_device *dev = to_gpio_sim_device(item); 709 bool live; 710 711 scoped_guard(mutex, &dev->lock) 712 live = gpio_sim_device_is_live(dev); 713 714 return sprintf(page, "%c\n", live ? '1' : '0'); 715 } 716 717 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank) 718 { 719 struct gpio_sim_line *line; 720 unsigned int size = 0; 721 722 list_for_each_entry(line, &bank->line_list, siblings) { 723 if (!line->name || (line->offset >= bank->num_lines)) 724 continue; 725 726 size = max(size, line->offset + 1); 727 } 728 729 return size; 730 } 731 732 static void 733 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 734 { 735 struct gpio_sim_line *line; 736 737 list_for_each_entry(line, &bank->line_list, siblings) { 738 if (!line->name || (line->offset >= bank->num_lines)) 739 continue; 740 741 line_names[line->offset] = line->name; 742 } 743 } 744 745 static unsigned int gpio_sim_get_reserved_ranges_size(struct gpio_sim_bank *bank) 746 { 747 struct gpio_sim_line *line; 748 unsigned int size = 0; 749 750 list_for_each_entry(line, &bank->line_list, siblings) { 751 if (line->valid) 752 continue; 753 754 size += 2; 755 } 756 757 return size; 758 } 759 760 static void gpio_sim_set_reserved_ranges(struct gpio_sim_bank *bank, 761 u32 *ranges) 762 { 763 struct gpio_sim_line *line; 764 int i = 0; 765 766 list_for_each_entry(line, &bank->line_list, siblings) { 767 if (line->valid) 768 continue; 769 770 ranges[i++] = line->offset; 771 ranges[i++] = 1; 772 } 773 } 774 775 static struct fwnode_handle * 776 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 777 struct fwnode_handle *parent) 778 { 779 unsigned int prop_idx = 0, line_names_size, ranges_size; 780 struct property_entry properties[GPIO_SIM_PROP_MAX]; 781 char **line_names __free(kfree) = NULL; 782 u32 *ranges __free(kfree) = NULL; 783 784 memset(properties, 0, sizeof(properties)); 785 786 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 787 788 if (gpio_sim_bank_has_label(bank)) 789 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 790 bank->label); 791 792 line_names_size = gpio_sim_get_line_names_size(bank); 793 if (line_names_size) { 794 line_names = kcalloc(line_names_size, sizeof(*line_names), 795 GFP_KERNEL); 796 if (!line_names) 797 return ERR_PTR(-ENOMEM); 798 799 gpio_sim_set_line_names(bank, line_names); 800 801 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 802 "gpio-line-names", 803 line_names, line_names_size); 804 } 805 806 ranges_size = gpio_sim_get_reserved_ranges_size(bank); 807 if (ranges_size) { 808 ranges = kcalloc(ranges_size, sizeof(u32), GFP_KERNEL); 809 if (!ranges) 810 return ERR_PTR(-ENOMEM); 811 812 gpio_sim_set_reserved_ranges(bank, ranges); 813 814 properties[prop_idx++] = PROPERTY_ENTRY_U32_ARRAY_LEN( 815 "gpio-reserved-ranges", 816 ranges, ranges_size); 817 } 818 819 return fwnode_create_software_node(properties, parent); 820 } 821 822 static int gpio_sim_bank_add_hogs(struct gpio_sim_bank *bank) 823 { 824 struct property_entry properties[GPIO_SIM_HOG_PROP_MAX]; 825 struct fwnode_handle *swnode; 826 struct gpio_sim_line *line; 827 struct gpio_sim_hog *hog; 828 unsigned int idx; 829 u32 gpios[2]; 830 831 list_for_each_entry(line, &bank->line_list, siblings) { 832 if (!line->hog) 833 continue; 834 835 hog = line->hog; 836 837 gpios[0] = line->offset; 838 gpios[1] = hog->active_low ? 1 : 0; 839 840 memset(properties, 0, sizeof(properties)); 841 842 idx = 0; 843 properties[idx++] = PROPERTY_ENTRY_BOOL("gpio-hog"); 844 properties[idx++] = PROPERTY_ENTRY_U32_ARRAY("gpios", gpios); 845 properties[idx++] = PROPERTY_ENTRY_STRING("line-name", hog->name); 846 847 switch (hog->dir) { 848 case GPIOD_IN: 849 properties[idx++] = PROPERTY_ENTRY_BOOL("input"); 850 break; 851 case GPIOD_OUT_HIGH: 852 properties[idx++] = PROPERTY_ENTRY_BOOL("output-high"); 853 break; 854 case GPIOD_OUT_LOW: 855 properties[idx++] = PROPERTY_ENTRY_BOOL("output-low"); 856 break; 857 default: 858 /* Would have been validated at configfs store. */ 859 WARN(1, "Unexpected hog direction value: %d", hog->dir); 860 return -EINVAL; 861 } 862 863 swnode = fwnode_create_software_node(properties, bank->swnode); 864 if (IS_ERR(swnode)) 865 return PTR_ERR(swnode); 866 } 867 868 return 0; 869 } 870 871 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 872 { 873 struct fwnode_handle *child; 874 875 fwnode_for_each_child_node(swnode, child) 876 gpio_sim_remove_swnode_recursive(child); 877 878 fwnode_remove_software_node(swnode); 879 } 880 881 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 882 { 883 struct gpio_sim_bank *this, *pos; 884 885 list_for_each_entry(this, &dev->bank_list, siblings) { 886 list_for_each_entry(pos, &dev->bank_list, siblings) { 887 if (this == pos || (!this->label || !pos->label)) 888 continue; 889 890 if (strcmp(this->label, pos->label) == 0) 891 return true; 892 } 893 } 894 895 return false; 896 } 897 898 static int gpio_sim_device_activate(struct gpio_sim_device *dev) 899 { 900 struct platform_device_info pdevinfo; 901 struct platform_device *pdev; 902 struct fwnode_handle *swnode; 903 struct gpio_sim_bank *bank; 904 int ret; 905 906 lockdep_assert_held(&dev->lock); 907 908 if (list_empty(&dev->bank_list)) 909 return -ENODATA; 910 911 /* 912 * Non-unique GPIO device labels are a corner-case we don't support 913 * as it would interfere with machine hogging mechanism and has little 914 * use in real life. 915 */ 916 if (gpio_sim_bank_labels_non_unique(dev)) 917 return -EINVAL; 918 919 memset(&pdevinfo, 0, sizeof(pdevinfo)); 920 921 swnode = fwnode_create_software_node(NULL, NULL); 922 if (IS_ERR(swnode)) 923 return PTR_ERR(swnode); 924 925 list_for_each_entry(bank, &dev->bank_list, siblings) { 926 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 927 if (IS_ERR(bank->swnode)) { 928 ret = PTR_ERR(bank->swnode); 929 goto err_remove_swnode; 930 } 931 932 ret = gpio_sim_bank_add_hogs(bank); 933 if (ret) 934 goto err_remove_swnode; 935 } 936 937 pdevinfo.name = "gpio-sim"; 938 pdevinfo.fwnode = swnode; 939 pdevinfo.id = dev->id; 940 941 pdev = platform_device_register_full(&pdevinfo); 942 if (IS_ERR(pdev)) { 943 ret = PTR_ERR(pdev); 944 goto err_remove_swnode; 945 } 946 947 wait_for_device_probe(); 948 if (!device_is_bound(&pdev->dev)) { 949 ret = -ENXIO; 950 goto err_unregister_pdev; 951 } 952 953 dev->pdev = pdev; 954 return 0; 955 956 err_unregister_pdev: 957 platform_device_unregister(pdev); 958 err_remove_swnode: 959 gpio_sim_remove_swnode_recursive(swnode); 960 961 return ret; 962 } 963 964 static void gpio_sim_device_deactivate(struct gpio_sim_device *dev) 965 { 966 struct fwnode_handle *swnode; 967 968 lockdep_assert_held(&dev->lock); 969 970 swnode = dev_fwnode(&dev->pdev->dev); 971 platform_device_unregister(dev->pdev); 972 dev->pdev = NULL; 973 gpio_sim_remove_swnode_recursive(swnode); 974 } 975 976 static void 977 gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock) 978 { 979 struct configfs_subsystem *subsys = dev->group.cg_subsys; 980 struct gpio_sim_bank *bank; 981 struct gpio_sim_line *line; 982 struct config_item *item; 983 984 /* 985 * The device only needs to depend on leaf entries. This is 986 * sufficient to lock up all the configfs entries that the 987 * instantiated, alive device depends on. 988 */ 989 list_for_each_entry(bank, &dev->bank_list, siblings) { 990 list_for_each_entry(line, &bank->line_list, siblings) { 991 item = line->hog ? &line->hog->item 992 : &line->group.cg_item; 993 994 if (lock) 995 WARN_ON(configfs_depend_item_unlocked(subsys, 996 item)); 997 else 998 configfs_undepend_item_unlocked(item); 999 } 1000 } 1001 } 1002 1003 static ssize_t 1004 gpio_sim_device_config_live_store(struct config_item *item, 1005 const char *page, size_t count) 1006 { 1007 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1008 bool live; 1009 int ret; 1010 1011 ret = kstrtobool(page, &live); 1012 if (ret) 1013 return ret; 1014 1015 if (live) 1016 gpio_sim_device_lockup_configfs(dev, true); 1017 1018 scoped_guard(mutex, &dev->lock) { 1019 if (live == gpio_sim_device_is_live(dev)) 1020 ret = -EPERM; 1021 else if (live) 1022 ret = gpio_sim_device_activate(dev); 1023 else 1024 gpio_sim_device_deactivate(dev); 1025 } 1026 1027 /* 1028 * Undepend is required only if device disablement (live == 0) 1029 * succeeds or if device enablement (live == 1) fails. 1030 */ 1031 if (live == !!ret) 1032 gpio_sim_device_lockup_configfs(dev, false); 1033 1034 return ret ?: count; 1035 } 1036 1037 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1038 1039 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1040 &gpio_sim_device_config_attr_dev_name, 1041 &gpio_sim_device_config_attr_live, 1042 NULL 1043 }; 1044 1045 struct gpio_sim_chip_name_ctx { 1046 struct fwnode_handle *swnode; 1047 char *page; 1048 }; 1049 1050 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1051 { 1052 struct gpio_sim_chip_name_ctx *ctx = data; 1053 1054 /* This would be the sysfs device exported in /sys/class/gpio. */ 1055 if (dev->class) 1056 return 0; 1057 1058 if (device_match_fwnode(dev, ctx->swnode)) 1059 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1060 1061 return 0; 1062 } 1063 1064 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1065 char *page) 1066 { 1067 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1068 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1069 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1070 1071 guard(mutex)(&dev->lock); 1072 1073 if (gpio_sim_device_is_live(dev)) 1074 return device_for_each_child(&dev->pdev->dev, &ctx, 1075 gpio_sim_emit_chip_name); 1076 1077 return sprintf(page, "none\n"); 1078 } 1079 1080 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1081 1082 static ssize_t 1083 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1084 { 1085 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1086 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1087 1088 guard(mutex)(&dev->lock); 1089 1090 return sprintf(page, "%s\n", bank->label ?: ""); 1091 } 1092 1093 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1094 const char *page, size_t count) 1095 { 1096 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1097 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1098 char *trimmed; 1099 1100 guard(mutex)(&dev->lock); 1101 1102 if (gpio_sim_device_is_live(dev)) 1103 return -EBUSY; 1104 1105 trimmed = gpio_sim_strdup_trimmed(page, count); 1106 if (!trimmed) 1107 return -ENOMEM; 1108 1109 kfree(bank->label); 1110 bank->label = trimmed; 1111 1112 return count; 1113 } 1114 1115 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1116 1117 static ssize_t 1118 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1119 { 1120 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1121 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1122 1123 guard(mutex)(&dev->lock); 1124 1125 return sprintf(page, "%u\n", bank->num_lines); 1126 } 1127 1128 static ssize_t 1129 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1130 const char *page, size_t count) 1131 { 1132 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1133 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1134 unsigned int num_lines; 1135 int ret; 1136 1137 ret = kstrtouint(page, 0, &num_lines); 1138 if (ret) 1139 return ret; 1140 1141 if (num_lines == 0) 1142 return -EINVAL; 1143 1144 guard(mutex)(&dev->lock); 1145 1146 if (gpio_sim_device_is_live(dev)) 1147 return -EBUSY; 1148 1149 bank->num_lines = num_lines; 1150 1151 return count; 1152 } 1153 1154 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1155 1156 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1157 &gpio_sim_bank_config_attr_chip_name, 1158 &gpio_sim_bank_config_attr_label, 1159 &gpio_sim_bank_config_attr_num_lines, 1160 NULL 1161 }; 1162 1163 static ssize_t 1164 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1165 { 1166 struct gpio_sim_line *line = to_gpio_sim_line(item); 1167 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1168 1169 guard(mutex)(&dev->lock); 1170 1171 return sprintf(page, "%s\n", line->name ?: ""); 1172 } 1173 1174 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1175 const char *page, size_t count) 1176 { 1177 struct gpio_sim_line *line = to_gpio_sim_line(item); 1178 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1179 char *trimmed; 1180 1181 guard(mutex)(&dev->lock); 1182 1183 if (gpio_sim_device_is_live(dev)) 1184 return -EBUSY; 1185 1186 trimmed = gpio_sim_strdup_trimmed(page, count); 1187 if (!trimmed) 1188 return -ENOMEM; 1189 1190 kfree(line->name); 1191 line->name = trimmed; 1192 1193 return count; 1194 } 1195 1196 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1197 1198 static ssize_t 1199 gpio_sim_line_config_valid_show(struct config_item *item, char *page) 1200 { 1201 struct gpio_sim_line *line = to_gpio_sim_line(item); 1202 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1203 1204 guard(mutex)(&dev->lock); 1205 1206 return sprintf(page, "%c\n", line->valid ? '1' : '0'); 1207 } 1208 1209 static ssize_t gpio_sim_line_config_valid_store(struct config_item *item, 1210 const char *page, size_t count) 1211 { 1212 struct gpio_sim_line *line = to_gpio_sim_line(item); 1213 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1214 bool valid; 1215 int ret; 1216 1217 ret = kstrtobool(page, &valid); 1218 if (ret) 1219 return ret; 1220 1221 guard(mutex)(&dev->lock); 1222 1223 line->valid = valid; 1224 1225 return count; 1226 } 1227 1228 CONFIGFS_ATTR(gpio_sim_line_config_, valid); 1229 1230 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1231 &gpio_sim_line_config_attr_name, 1232 &gpio_sim_line_config_attr_valid, 1233 NULL 1234 }; 1235 1236 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1237 char *page) 1238 { 1239 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1240 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1241 1242 guard(mutex)(&dev->lock); 1243 1244 return sprintf(page, "%s\n", hog->name ?: ""); 1245 } 1246 1247 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1248 const char *page, size_t count) 1249 { 1250 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1251 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1252 char *trimmed; 1253 1254 guard(mutex)(&dev->lock); 1255 1256 if (gpio_sim_device_is_live(dev)) 1257 return -EBUSY; 1258 1259 trimmed = gpio_sim_strdup_trimmed(page, count); 1260 if (!trimmed) 1261 return -ENOMEM; 1262 1263 kfree(hog->name); 1264 hog->name = trimmed; 1265 1266 return count; 1267 } 1268 1269 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1270 1271 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1272 char *page) 1273 { 1274 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1275 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1276 char *repr; 1277 int dir; 1278 1279 scoped_guard(mutex, &dev->lock) 1280 dir = hog->dir; 1281 1282 switch (dir) { 1283 case GPIOD_IN: 1284 repr = "input"; 1285 break; 1286 case GPIOD_OUT_HIGH: 1287 repr = "output-high"; 1288 break; 1289 case GPIOD_OUT_LOW: 1290 repr = "output-low"; 1291 break; 1292 default: 1293 /* This would be a programmer bug. */ 1294 WARN(1, "Unexpected hog direction value: %d", dir); 1295 return -EINVAL; 1296 } 1297 1298 return sprintf(page, "%s\n", repr); 1299 } 1300 1301 static ssize_t 1302 gpio_sim_hog_config_direction_store(struct config_item *item, 1303 const char *page, size_t count) 1304 { 1305 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1306 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1307 int dir; 1308 1309 guard(mutex)(&dev->lock); 1310 1311 if (gpio_sim_device_is_live(dev)) 1312 return -EBUSY; 1313 1314 if (sysfs_streq(page, "input")) 1315 dir = GPIOD_IN; 1316 else if (sysfs_streq(page, "output-high")) 1317 dir = GPIOD_OUT_HIGH; 1318 else if (sysfs_streq(page, "output-low")) 1319 dir = GPIOD_OUT_LOW; 1320 else 1321 return -EINVAL; 1322 1323 hog->dir = dir; 1324 1325 return count; 1326 } 1327 1328 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1329 1330 static ssize_t gpio_sim_hog_config_active_low_show(struct config_item *item, 1331 char *page) 1332 { 1333 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1334 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1335 1336 guard(mutex)(&dev->lock); 1337 1338 return sprintf(page, "%c\n", hog->active_low ? '1' : '0'); 1339 } 1340 1341 static ssize_t 1342 gpio_sim_hog_config_active_low_store(struct config_item *item, 1343 const char *page, size_t count) 1344 { 1345 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1346 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1347 bool active_low; 1348 int ret; 1349 1350 guard(mutex)(&dev->lock); 1351 1352 if (gpio_sim_device_is_live(dev)) 1353 return -EBUSY; 1354 1355 ret = kstrtobool(page, &active_low); 1356 if (ret) 1357 return ret; 1358 1359 hog->active_low = active_low; 1360 1361 return count; 1362 } 1363 1364 CONFIGFS_ATTR(gpio_sim_hog_config_, active_low); 1365 1366 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1367 &gpio_sim_hog_config_attr_name, 1368 &gpio_sim_hog_config_attr_direction, 1369 &gpio_sim_hog_config_attr_active_low, 1370 NULL 1371 }; 1372 1373 static void gpio_sim_hog_config_item_release(struct config_item *item) 1374 { 1375 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1376 struct gpio_sim_line *line = hog->parent; 1377 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1378 1379 scoped_guard(mutex, &dev->lock) 1380 line->hog = NULL; 1381 1382 kfree(hog->name); 1383 kfree(hog); 1384 } 1385 1386 static const struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1387 .release = gpio_sim_hog_config_item_release, 1388 }; 1389 1390 static const struct config_item_type gpio_sim_hog_config_type = { 1391 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1392 .ct_attrs = gpio_sim_hog_config_attrs, 1393 .ct_owner = THIS_MODULE, 1394 }; 1395 1396 static struct config_item * 1397 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1398 { 1399 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1400 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1401 struct gpio_sim_hog *hog; 1402 1403 if (strcmp(name, "hog") != 0) 1404 return ERR_PTR(-EINVAL); 1405 1406 guard(mutex)(&dev->lock); 1407 1408 hog = kzalloc_obj(*hog); 1409 if (!hog) 1410 return ERR_PTR(-ENOMEM); 1411 1412 config_item_init_type_name(&hog->item, name, 1413 &gpio_sim_hog_config_type); 1414 1415 hog->dir = GPIOD_IN; 1416 hog->name = NULL; 1417 hog->parent = line; 1418 line->hog = hog; 1419 1420 return &hog->item; 1421 } 1422 1423 static void gpio_sim_line_config_group_release(struct config_item *item) 1424 { 1425 struct gpio_sim_line *line = to_gpio_sim_line(item); 1426 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1427 1428 scoped_guard(mutex, &dev->lock) 1429 list_del(&line->siblings); 1430 1431 kfree(line->name); 1432 kfree(line); 1433 } 1434 1435 static const struct configfs_item_operations gpio_sim_line_config_item_ops = { 1436 .release = gpio_sim_line_config_group_release, 1437 }; 1438 1439 static const struct configfs_group_operations gpio_sim_line_config_group_ops = { 1440 .make_item = gpio_sim_line_config_make_hog_item, 1441 }; 1442 1443 static const struct config_item_type gpio_sim_line_config_type = { 1444 .ct_item_ops = &gpio_sim_line_config_item_ops, 1445 .ct_group_ops = &gpio_sim_line_config_group_ops, 1446 .ct_attrs = gpio_sim_line_config_attrs, 1447 .ct_owner = THIS_MODULE, 1448 }; 1449 1450 static struct config_group * 1451 gpio_sim_bank_config_make_line_group(struct config_group *group, 1452 const char *name) 1453 { 1454 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1455 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1456 struct gpio_sim_line *line; 1457 unsigned int offset; 1458 int ret, nchar; 1459 1460 ret = sscanf(name, "line%u%n", &offset, &nchar); 1461 if (ret != 1 || nchar != strlen(name)) 1462 return ERR_PTR(-EINVAL); 1463 1464 guard(mutex)(&dev->lock); 1465 1466 if (gpio_sim_device_is_live(dev)) 1467 return ERR_PTR(-EBUSY); 1468 1469 line = kzalloc_obj(*line); 1470 if (!line) 1471 return ERR_PTR(-ENOMEM); 1472 1473 config_group_init_type_name(&line->group, name, 1474 &gpio_sim_line_config_type); 1475 1476 line->parent = bank; 1477 line->offset = offset; 1478 line->valid = true; 1479 list_add_tail(&line->siblings, &bank->line_list); 1480 1481 return &line->group; 1482 } 1483 1484 static void gpio_sim_bank_config_group_release(struct config_item *item) 1485 { 1486 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1487 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1488 1489 scoped_guard(mutex, &dev->lock) 1490 list_del(&bank->siblings); 1491 1492 kfree(bank->label); 1493 kfree(bank); 1494 } 1495 1496 static const struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1497 .release = gpio_sim_bank_config_group_release, 1498 }; 1499 1500 static const struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1501 .make_group = gpio_sim_bank_config_make_line_group, 1502 }; 1503 1504 static const struct config_item_type gpio_sim_bank_config_group_type = { 1505 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1506 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1507 .ct_attrs = gpio_sim_bank_config_attrs, 1508 .ct_owner = THIS_MODULE, 1509 }; 1510 1511 static struct config_group * 1512 gpio_sim_device_config_make_bank_group(struct config_group *group, 1513 const char *name) 1514 { 1515 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1516 struct gpio_sim_bank *bank; 1517 1518 guard(mutex)(&dev->lock); 1519 1520 if (gpio_sim_device_is_live(dev)) 1521 return ERR_PTR(-EBUSY); 1522 1523 bank = kzalloc_obj(*bank); 1524 if (!bank) 1525 return ERR_PTR(-ENOMEM); 1526 1527 config_group_init_type_name(&bank->group, name, 1528 &gpio_sim_bank_config_group_type); 1529 bank->num_lines = 1; 1530 bank->parent = dev; 1531 INIT_LIST_HEAD(&bank->line_list); 1532 list_add_tail(&bank->siblings, &dev->bank_list); 1533 1534 return &bank->group; 1535 } 1536 1537 static void gpio_sim_device_config_group_release(struct config_item *item) 1538 { 1539 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1540 1541 scoped_guard(mutex, &dev->lock) { 1542 if (gpio_sim_device_is_live(dev)) 1543 gpio_sim_device_deactivate(dev); 1544 } 1545 1546 mutex_destroy(&dev->lock); 1547 ida_free(&gpio_sim_ida, dev->id); 1548 kfree(dev); 1549 } 1550 1551 static const struct configfs_item_operations gpio_sim_device_config_item_ops = { 1552 .release = gpio_sim_device_config_group_release, 1553 }; 1554 1555 static const struct configfs_group_operations gpio_sim_device_config_group_ops = { 1556 .make_group = gpio_sim_device_config_make_bank_group, 1557 }; 1558 1559 static const struct config_item_type gpio_sim_device_config_group_type = { 1560 .ct_item_ops = &gpio_sim_device_config_item_ops, 1561 .ct_group_ops = &gpio_sim_device_config_group_ops, 1562 .ct_attrs = gpio_sim_device_config_attrs, 1563 .ct_owner = THIS_MODULE, 1564 }; 1565 1566 static struct config_group * 1567 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1568 { 1569 int id; 1570 1571 struct gpio_sim_device *dev __free(kfree) = kzalloc_obj(*dev); 1572 if (!dev) 1573 return ERR_PTR(-ENOMEM); 1574 1575 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1576 if (id < 0) 1577 return ERR_PTR(id); 1578 1579 config_group_init_type_name(&dev->group, name, 1580 &gpio_sim_device_config_group_type); 1581 dev->id = id; 1582 mutex_init(&dev->lock); 1583 INIT_LIST_HEAD(&dev->bank_list); 1584 1585 return &no_free_ptr(dev)->group; 1586 } 1587 1588 static const struct configfs_group_operations gpio_sim_config_group_ops = { 1589 .make_group = gpio_sim_config_make_device_group, 1590 }; 1591 1592 static const struct config_item_type gpio_sim_config_type = { 1593 .ct_group_ops = &gpio_sim_config_group_ops, 1594 .ct_owner = THIS_MODULE, 1595 }; 1596 1597 static struct configfs_subsystem gpio_sim_config_subsys = { 1598 .su_group = { 1599 .cg_item = { 1600 .ci_namebuf = "gpio-sim", 1601 .ci_type = &gpio_sim_config_type, 1602 }, 1603 }, 1604 }; 1605 1606 static int __init gpio_sim_init(void) 1607 { 1608 int ret; 1609 1610 ret = platform_driver_register(&gpio_sim_driver); 1611 if (ret) { 1612 pr_err("Error %d while registering the platform driver\n", ret); 1613 return ret; 1614 } 1615 1616 config_group_init(&gpio_sim_config_subsys.su_group); 1617 mutex_init(&gpio_sim_config_subsys.su_mutex); 1618 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1619 if (ret) { 1620 pr_err("Error %d while registering the configfs subsystem %s\n", 1621 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1622 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1623 platform_driver_unregister(&gpio_sim_driver); 1624 return ret; 1625 } 1626 1627 return 0; 1628 } 1629 module_init(gpio_sim_init); 1630 1631 static void __exit gpio_sim_exit(void) 1632 { 1633 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1634 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1635 platform_driver_unregister(&gpio_sim_driver); 1636 } 1637 module_exit(gpio_sim_exit); 1638 1639 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); 1640 MODULE_DESCRIPTION("GPIO Simulator Module"); 1641 MODULE_LICENSE("GPL"); 1642