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 #include "dev-sync-probe.h" 40 41 #define GPIO_SIM_NGPIO_MAX 1024 42 #define GPIO_SIM_PROP_MAX 5 /* Max 4 properties + sentinel. */ 43 #define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */ 44 45 static DEFINE_IDA(gpio_sim_ida); 46 47 struct gpio_sim_chip { 48 struct gpio_chip gc; 49 struct device *dev; 50 unsigned long *request_map; 51 unsigned long *direction_map; 52 unsigned long *value_map; 53 unsigned long *pull_map; 54 struct irq_domain *irq_sim; 55 struct mutex lock; 56 const struct attribute_group **attr_groups; 57 }; 58 59 struct gpio_sim_attribute { 60 struct device_attribute dev_attr; 61 unsigned int offset; 62 }; 63 64 static struct gpio_sim_attribute * 65 to_gpio_sim_attr(struct device_attribute *dev_attr) 66 { 67 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 68 } 69 70 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 71 unsigned int offset, int value) 72 { 73 int irq, irq_type, ret; 74 75 guard(mutex)(&chip->lock); 76 77 if (test_bit(offset, chip->request_map) && 78 test_bit(offset, chip->direction_map)) { 79 if (value == !!test_bit(offset, chip->value_map)) 80 goto set_pull; 81 82 /* 83 * This is fine - it just means, nobody is listening 84 * for interrupts on this line, otherwise 85 * irq_create_mapping() would have been called from 86 * the to_irq() callback. 87 */ 88 irq = irq_find_mapping(chip->irq_sim, offset); 89 if (!irq) 90 goto set_value; 91 92 irq_type = irq_get_trigger_type(irq); 93 94 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) || 95 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) { 96 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 97 true); 98 if (ret) 99 goto set_pull; 100 } 101 } 102 103 set_value: 104 /* Change the value unless we're actively driving the line. */ 105 if (!test_bit(offset, chip->request_map) || 106 test_bit(offset, chip->direction_map)) 107 __assign_bit(offset, chip->value_map, value); 108 109 set_pull: 110 __assign_bit(offset, chip->pull_map, value); 111 return 0; 112 } 113 114 static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset) 115 { 116 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 117 118 guard(mutex)(&chip->lock); 119 120 return !!test_bit(offset, chip->value_map); 121 } 122 123 static int gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value) 124 { 125 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 126 127 scoped_guard(mutex, &chip->lock) 128 __assign_bit(offset, chip->value_map, value); 129 130 return 0; 131 } 132 133 static int gpio_sim_get_multiple(struct gpio_chip *gc, 134 unsigned long *mask, unsigned long *bits) 135 { 136 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 137 138 scoped_guard(mutex, &chip->lock) 139 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 140 141 return 0; 142 } 143 144 static int gpio_sim_set_multiple(struct gpio_chip *gc, 145 unsigned long *mask, unsigned long *bits) 146 { 147 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 148 149 scoped_guard(mutex, &chip->lock) 150 bitmap_replace(chip->value_map, chip->value_map, bits, mask, 151 gc->ngpio); 152 153 return 0; 154 } 155 156 static int gpio_sim_direction_output(struct gpio_chip *gc, 157 unsigned int offset, int value) 158 { 159 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 160 161 scoped_guard(mutex, &chip->lock) { 162 __clear_bit(offset, chip->direction_map); 163 __assign_bit(offset, chip->value_map, value); 164 } 165 166 return 0; 167 } 168 169 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 170 { 171 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 172 173 scoped_guard(mutex, &chip->lock) 174 __set_bit(offset, chip->direction_map); 175 176 return 0; 177 } 178 179 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 180 { 181 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 182 int direction; 183 184 scoped_guard(mutex, &chip->lock) 185 direction = !!test_bit(offset, chip->direction_map); 186 187 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; 188 } 189 190 static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset, 191 unsigned long config) 192 { 193 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 194 195 switch (pinconf_to_config_param(config)) { 196 case PIN_CONFIG_BIAS_PULL_UP: 197 return gpio_sim_apply_pull(chip, offset, 1); 198 case PIN_CONFIG_BIAS_PULL_DOWN: 199 return gpio_sim_apply_pull(chip, offset, 0); 200 default: 201 break; 202 } 203 204 return -ENOTSUPP; 205 } 206 207 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 208 { 209 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 210 211 return irq_create_mapping(chip->irq_sim, offset); 212 } 213 214 static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset) 215 { 216 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 217 218 scoped_guard(mutex, &chip->lock) 219 __set_bit(offset, chip->request_map); 220 221 return 0; 222 } 223 224 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 225 { 226 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 227 228 scoped_guard(mutex, &chip->lock) { 229 __assign_bit(offset, chip->value_map, 230 !!test_bit(offset, chip->pull_map)); 231 __clear_bit(offset, chip->request_map); 232 } 233 } 234 235 static int gpio_sim_irq_requested(struct irq_domain *domain, 236 irq_hw_number_t hwirq, void *data) 237 { 238 struct gpio_sim_chip *chip = data; 239 240 return gpiochip_lock_as_irq(&chip->gc, hwirq); 241 } 242 243 static void gpio_sim_irq_released(struct irq_domain *domain, 244 irq_hw_number_t hwirq, void *data) 245 { 246 struct gpio_sim_chip *chip = data; 247 248 gpiochip_unlock_as_irq(&chip->gc, hwirq); 249 } 250 251 static const struct irq_sim_ops gpio_sim_irq_sim_ops = { 252 .irq_sim_irq_requested = gpio_sim_irq_requested, 253 .irq_sim_irq_released = gpio_sim_irq_released, 254 }; 255 256 static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc) 257 { 258 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 259 const char *label; 260 int i; 261 262 guard(mutex)(&chip->lock); 263 264 for_each_hwgpio(gc, i, label) 265 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n", 266 gc->base + i, 267 label ?: "<unused>", 268 test_bit(i, chip->direction_map) ? "input" : 269 test_bit(i, chip->value_map) ? "output-high" : 270 "output-low", 271 test_bit(i, chip->pull_map) ? "pull-up" : 272 "pull-down"); 273 } 274 275 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 276 struct device_attribute *attr, char *buf) 277 { 278 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 279 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 280 int val; 281 282 scoped_guard(mutex, &chip->lock) 283 val = !!test_bit(line_attr->offset, chip->value_map); 284 285 return sysfs_emit(buf, "%d\n", val); 286 } 287 288 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 289 struct device_attribute *attr, 290 const char *buf, size_t count) 291 { 292 /* 293 * Not assigning this function will result in write() returning -EIO 294 * which is confusing. Return -EPERM explicitly. 295 */ 296 return -EPERM; 297 } 298 299 static const char *const gpio_sim_sysfs_pull_strings[] = { 300 [0] = "pull-down", 301 [1] = "pull-up", 302 }; 303 304 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 305 struct device_attribute *attr, 306 char *buf) 307 { 308 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 309 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 310 int pull; 311 312 scoped_guard(mutex, &chip->lock) 313 pull = !!test_bit(line_attr->offset, chip->pull_map); 314 315 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 316 } 317 318 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 319 struct device_attribute *attr, 320 const char *buf, size_t len) 321 { 322 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 323 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 324 int ret, pull; 325 326 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 327 if (pull < 0) 328 return pull; 329 330 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 331 if (ret) 332 return ret; 333 334 return len; 335 } 336 337 static void gpio_sim_put_device(void *data) 338 { 339 struct device *dev = data; 340 341 put_device(dev); 342 } 343 344 static void gpio_sim_dispose_mappings(void *data) 345 { 346 struct gpio_sim_chip *chip = data; 347 unsigned int i; 348 349 for (i = 0; i < chip->gc.ngpio; i++) 350 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 351 } 352 353 static void gpio_sim_sysfs_remove(void *data) 354 { 355 struct gpio_sim_chip *chip = data; 356 357 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups); 358 } 359 360 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 361 { 362 struct device_attribute *val_dev_attr, *pull_dev_attr; 363 struct gpio_sim_attribute *val_attr, *pull_attr; 364 unsigned int num_lines = chip->gc.ngpio; 365 struct device *dev = chip->gc.parent; 366 struct attribute_group *attr_group; 367 struct attribute **attrs; 368 int i, ret; 369 370 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 371 num_lines + 1, GFP_KERNEL); 372 if (!chip->attr_groups) 373 return -ENOMEM; 374 375 for (i = 0; i < num_lines; i++) { 376 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 377 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 378 GFP_KERNEL); 379 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 380 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 381 if (!attr_group || !attrs || !val_attr || !pull_attr) 382 return -ENOMEM; 383 384 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 385 "sim_gpio%u", i); 386 if (!attr_group->name) 387 return -ENOMEM; 388 389 val_attr->offset = pull_attr->offset = i; 390 391 val_dev_attr = &val_attr->dev_attr; 392 pull_dev_attr = &pull_attr->dev_attr; 393 394 sysfs_attr_init(&val_dev_attr->attr); 395 sysfs_attr_init(&pull_dev_attr->attr); 396 397 val_dev_attr->attr.name = "value"; 398 pull_dev_attr->attr.name = "pull"; 399 400 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 401 402 val_dev_attr->show = gpio_sim_sysfs_val_show; 403 val_dev_attr->store = gpio_sim_sysfs_val_store; 404 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 405 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 406 407 attrs[0] = &val_dev_attr->attr; 408 attrs[1] = &pull_dev_attr->attr; 409 410 attr_group->attrs = attrs; 411 chip->attr_groups[i] = attr_group; 412 } 413 414 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups); 415 if (ret) 416 return ret; 417 418 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 419 } 420 421 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 422 { 423 struct gpio_sim_chip *chip; 424 struct gpio_chip *gc; 425 const char *label; 426 u32 num_lines; 427 int ret; 428 429 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 430 if (ret) 431 return ret; 432 433 if (num_lines > GPIO_SIM_NGPIO_MAX) 434 return -ERANGE; 435 436 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 437 if (ret) { 438 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP", 439 dev_name(dev), swnode); 440 if (!label) 441 return -ENOMEM; 442 } 443 444 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 445 if (!chip) 446 return -ENOMEM; 447 448 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 449 if (!chip->request_map) 450 return -ENOMEM; 451 452 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 453 if (!chip->direction_map) 454 return -ENOMEM; 455 456 /* Default to input mode. */ 457 bitmap_fill(chip->direction_map, num_lines); 458 459 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 460 if (!chip->value_map) 461 return -ENOMEM; 462 463 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 464 if (!chip->pull_map) 465 return -ENOMEM; 466 467 chip->irq_sim = devm_irq_domain_create_sim_full(dev, swnode, num_lines, 468 &gpio_sim_irq_sim_ops, 469 chip); 470 if (IS_ERR(chip->irq_sim)) 471 return PTR_ERR(chip->irq_sim); 472 473 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 474 if (ret) 475 return ret; 476 477 ret = devm_mutex_init(dev, &chip->lock); 478 if (ret) 479 return ret; 480 481 gc = &chip->gc; 482 gc->base = -1; 483 gc->ngpio = num_lines; 484 gc->label = label; 485 gc->owner = THIS_MODULE; 486 gc->parent = dev; 487 gc->fwnode = swnode; 488 gc->get = gpio_sim_get; 489 gc->set = gpio_sim_set; 490 gc->get_multiple = gpio_sim_get_multiple; 491 gc->set_multiple = gpio_sim_set_multiple; 492 gc->direction_output = gpio_sim_direction_output; 493 gc->direction_input = gpio_sim_direction_input; 494 gc->get_direction = gpio_sim_get_direction; 495 gc->set_config = gpio_sim_set_config; 496 gc->to_irq = gpio_sim_to_irq; 497 gc->request = gpio_sim_request; 498 gc->free = gpio_sim_free; 499 gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show); 500 gc->can_sleep = true; 501 502 ret = devm_gpiochip_add_data(dev, gc, chip); 503 if (ret) 504 return ret; 505 506 chip->dev = device_find_child(dev, swnode, device_match_fwnode); 507 if (!chip->dev) 508 return -ENODEV; 509 510 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev); 511 if (ret) 512 return ret; 513 514 /* Used by sysfs callbacks. */ 515 dev_set_drvdata(chip->dev, chip); 516 517 return gpio_sim_setup_sysfs(chip); 518 } 519 520 static int gpio_sim_probe(struct platform_device *pdev) 521 { 522 struct device *dev = &pdev->dev; 523 int ret; 524 525 device_for_each_child_node_scoped(dev, swnode) { 526 ret = gpio_sim_add_bank(swnode, dev); 527 if (ret) 528 return ret; 529 } 530 531 return 0; 532 } 533 534 static const struct of_device_id gpio_sim_of_match[] = { 535 { .compatible = "gpio-simulator" }, 536 { } 537 }; 538 MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 539 540 static struct platform_driver gpio_sim_driver = { 541 .driver = { 542 .name = "gpio-sim", 543 .of_match_table = gpio_sim_of_match, 544 }, 545 .probe = gpio_sim_probe, 546 }; 547 548 struct gpio_sim_device { 549 struct dev_sync_probe_data probe_data; 550 struct config_group group; 551 552 int id; 553 554 /* 555 * Each configfs filesystem operation is protected with the subsystem 556 * mutex. Each separate attribute is protected with the buffer mutex. 557 * This structure however can be modified by callbacks of different 558 * attributes so we need another lock. 559 * 560 * We use this lock for protecting all data structures owned by this 561 * object too. 562 */ 563 struct mutex lock; 564 565 struct gpiod_hog *hogs; 566 567 struct list_head bank_list; 568 }; 569 570 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 571 { 572 struct config_group *group = to_config_group(item); 573 574 return container_of(group, struct gpio_sim_device, group); 575 } 576 577 struct gpio_sim_bank { 578 struct config_group group; 579 580 /* 581 * We could have used the ci_parent field of the config_item but 582 * configfs is stupid and calls the item's release callback after 583 * already having cleared the parent pointer even though the parent 584 * is guaranteed to survive the child... 585 * 586 * So we need to store the pointer to the parent struct here. We can 587 * dereference it anywhere we need with no checks and no locking as 588 * it's guaranteed to survive the children and protected by configfs 589 * locks. 590 * 591 * Same for other structures. 592 */ 593 struct gpio_sim_device *parent; 594 struct list_head siblings; 595 596 char *label; 597 unsigned int num_lines; 598 599 struct list_head line_list; 600 601 struct fwnode_handle *swnode; 602 }; 603 604 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 605 { 606 struct config_group *group = to_config_group(item); 607 608 return container_of(group, struct gpio_sim_bank, group); 609 } 610 611 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 612 { 613 return bank->label && *bank->label; 614 } 615 616 static struct gpio_sim_device * 617 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 618 { 619 return bank->parent; 620 } 621 622 struct gpio_sim_hog; 623 624 struct gpio_sim_line { 625 struct config_group group; 626 627 struct gpio_sim_bank *parent; 628 struct list_head siblings; 629 630 unsigned int offset; 631 char *name; 632 bool valid; 633 634 /* There can only be one hog per line. */ 635 struct gpio_sim_hog *hog; 636 }; 637 638 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 639 { 640 struct config_group *group = to_config_group(item); 641 642 return container_of(group, struct gpio_sim_line, group); 643 } 644 645 static struct gpio_sim_device * 646 gpio_sim_line_get_device(struct gpio_sim_line *line) 647 { 648 struct gpio_sim_bank *bank = line->parent; 649 650 return gpio_sim_bank_get_device(bank); 651 } 652 653 struct gpio_sim_hog { 654 struct config_item item; 655 struct gpio_sim_line *parent; 656 657 char *name; 658 int dir; 659 }; 660 661 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 662 { 663 return container_of(item, struct gpio_sim_hog, item); 664 } 665 666 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 667 { 668 struct gpio_sim_line *line = hog->parent; 669 670 return gpio_sim_line_get_device(line); 671 } 672 673 static bool gpio_sim_device_is_live(struct gpio_sim_device *dev) 674 { 675 lockdep_assert_held(&dev->lock); 676 677 return !!dev->probe_data.pdev; 678 } 679 680 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 681 { 682 char *trimmed; 683 684 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 685 if (!trimmed) 686 return NULL; 687 688 return strim(trimmed); 689 } 690 691 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 692 char *page) 693 { 694 struct gpio_sim_device *dev = to_gpio_sim_device(item); 695 struct platform_device *pdev; 696 697 guard(mutex)(&dev->lock); 698 699 pdev = dev->probe_data.pdev; 700 if (pdev) 701 return sprintf(page, "%s\n", dev_name(&pdev->dev)); 702 703 return sprintf(page, "gpio-sim.%d\n", dev->id); 704 } 705 706 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 707 708 static ssize_t 709 gpio_sim_device_config_live_show(struct config_item *item, char *page) 710 { 711 struct gpio_sim_device *dev = to_gpio_sim_device(item); 712 bool live; 713 714 scoped_guard(mutex, &dev->lock) 715 live = gpio_sim_device_is_live(dev); 716 717 return sprintf(page, "%c\n", live ? '1' : '0'); 718 } 719 720 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank) 721 { 722 struct gpio_sim_line *line; 723 unsigned int size = 0; 724 725 list_for_each_entry(line, &bank->line_list, siblings) { 726 if (!line->name || (line->offset >= bank->num_lines)) 727 continue; 728 729 size = max(size, line->offset + 1); 730 } 731 732 return size; 733 } 734 735 static void 736 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 737 { 738 struct gpio_sim_line *line; 739 740 list_for_each_entry(line, &bank->line_list, siblings) { 741 if (!line->name || (line->offset >= bank->num_lines)) 742 continue; 743 744 line_names[line->offset] = line->name; 745 } 746 } 747 748 static unsigned int gpio_sim_get_reserved_ranges_size(struct gpio_sim_bank *bank) 749 { 750 struct gpio_sim_line *line; 751 unsigned int size = 0; 752 753 list_for_each_entry(line, &bank->line_list, siblings) { 754 if (line->valid) 755 continue; 756 757 size += 2; 758 } 759 760 return size; 761 } 762 763 static void gpio_sim_set_reserved_ranges(struct gpio_sim_bank *bank, 764 u32 *ranges) 765 { 766 struct gpio_sim_line *line; 767 int i = 0; 768 769 list_for_each_entry(line, &bank->line_list, siblings) { 770 if (line->valid) 771 continue; 772 773 ranges[i++] = line->offset; 774 ranges[i++] = 1; 775 } 776 } 777 778 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 779 { 780 struct gpiod_hog *hog; 781 782 if (!dev->hogs) 783 return; 784 785 gpiod_remove_hogs(dev->hogs); 786 787 for (hog = dev->hogs; hog->chip_label; hog++) { 788 kfree(hog->chip_label); 789 kfree(hog->line_name); 790 } 791 792 kfree(dev->hogs); 793 dev->hogs = NULL; 794 } 795 796 static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 797 { 798 unsigned int num_hogs = 0, idx = 0; 799 struct gpio_sim_bank *bank; 800 struct gpio_sim_line *line; 801 struct gpiod_hog *hog; 802 803 list_for_each_entry(bank, &dev->bank_list, siblings) { 804 list_for_each_entry(line, &bank->line_list, siblings) { 805 if (line->offset >= bank->num_lines) 806 continue; 807 808 if (line->hog) 809 num_hogs++; 810 } 811 } 812 813 if (!num_hogs) 814 return 0; 815 816 /* Allocate one more for the sentinel. */ 817 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 818 if (!dev->hogs) 819 return -ENOMEM; 820 821 list_for_each_entry(bank, &dev->bank_list, siblings) { 822 list_for_each_entry(line, &bank->line_list, siblings) { 823 if (line->offset >= bank->num_lines) 824 continue; 825 826 if (!line->hog) 827 continue; 828 829 hog = &dev->hogs[idx++]; 830 831 /* 832 * We need to make this string manually because at this 833 * point the device doesn't exist yet and so dev_name() 834 * is not available. 835 */ 836 if (gpio_sim_bank_has_label(bank)) 837 hog->chip_label = kstrdup(bank->label, 838 GFP_KERNEL); 839 else 840 hog->chip_label = kasprintf(GFP_KERNEL, 841 "gpio-sim.%u:%pfwP", 842 dev->id, 843 bank->swnode); 844 if (!hog->chip_label) { 845 gpio_sim_remove_hogs(dev); 846 return -ENOMEM; 847 } 848 849 /* 850 * We need to duplicate this because the hog config 851 * item can be removed at any time (and we can't block 852 * it) and gpiolib doesn't make a deep copy of the hog 853 * data. 854 */ 855 if (line->hog->name) { 856 hog->line_name = kstrdup(line->hog->name, 857 GFP_KERNEL); 858 if (!hog->line_name) { 859 gpio_sim_remove_hogs(dev); 860 return -ENOMEM; 861 } 862 } 863 864 hog->chip_hwnum = line->offset; 865 hog->dflags = line->hog->dir; 866 } 867 } 868 869 gpiod_add_hogs(dev->hogs); 870 871 return 0; 872 } 873 874 static struct fwnode_handle * 875 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 876 struct fwnode_handle *parent) 877 { 878 unsigned int prop_idx = 0, line_names_size, ranges_size; 879 struct property_entry properties[GPIO_SIM_PROP_MAX]; 880 char **line_names __free(kfree) = NULL; 881 u32 *ranges __free(kfree) = NULL; 882 883 memset(properties, 0, sizeof(properties)); 884 885 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 886 887 if (gpio_sim_bank_has_label(bank)) 888 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 889 bank->label); 890 891 line_names_size = gpio_sim_get_line_names_size(bank); 892 if (line_names_size) { 893 line_names = kcalloc(line_names_size, sizeof(*line_names), 894 GFP_KERNEL); 895 if (!line_names) 896 return ERR_PTR(-ENOMEM); 897 898 gpio_sim_set_line_names(bank, line_names); 899 900 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 901 "gpio-line-names", 902 line_names, line_names_size); 903 } 904 905 ranges_size = gpio_sim_get_reserved_ranges_size(bank); 906 if (ranges_size) { 907 ranges = kcalloc(ranges_size, sizeof(u32), GFP_KERNEL); 908 if (!ranges) 909 return ERR_PTR(-ENOMEM); 910 911 gpio_sim_set_reserved_ranges(bank, ranges); 912 913 properties[prop_idx++] = PROPERTY_ENTRY_U32_ARRAY_LEN( 914 "gpio-reserved-ranges", 915 ranges, ranges_size); 916 } 917 918 return fwnode_create_software_node(properties, parent); 919 } 920 921 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 922 { 923 struct fwnode_handle *child; 924 925 fwnode_for_each_child_node(swnode, child) 926 fwnode_remove_software_node(child); 927 928 fwnode_remove_software_node(swnode); 929 } 930 931 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 932 { 933 struct gpio_sim_bank *this, *pos; 934 935 list_for_each_entry(this, &dev->bank_list, siblings) { 936 list_for_each_entry(pos, &dev->bank_list, siblings) { 937 if (this == pos || (!this->label || !pos->label)) 938 continue; 939 940 if (strcmp(this->label, pos->label) == 0) 941 return true; 942 } 943 } 944 945 return false; 946 } 947 948 static int gpio_sim_device_activate(struct gpio_sim_device *dev) 949 { 950 struct platform_device_info pdevinfo; 951 struct fwnode_handle *swnode; 952 struct gpio_sim_bank *bank; 953 int ret; 954 955 lockdep_assert_held(&dev->lock); 956 957 if (list_empty(&dev->bank_list)) 958 return -ENODATA; 959 960 /* 961 * Non-unique GPIO device labels are a corner-case we don't support 962 * as it would interfere with machine hogging mechanism and has little 963 * use in real life. 964 */ 965 if (gpio_sim_bank_labels_non_unique(dev)) 966 return -EINVAL; 967 968 memset(&pdevinfo, 0, sizeof(pdevinfo)); 969 970 swnode = fwnode_create_software_node(NULL, NULL); 971 if (IS_ERR(swnode)) 972 return PTR_ERR(swnode); 973 974 list_for_each_entry(bank, &dev->bank_list, siblings) { 975 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 976 if (IS_ERR(bank->swnode)) { 977 ret = PTR_ERR(bank->swnode); 978 gpio_sim_remove_swnode_recursive(swnode); 979 return ret; 980 } 981 } 982 983 ret = gpio_sim_add_hogs(dev); 984 if (ret) { 985 gpio_sim_remove_swnode_recursive(swnode); 986 return ret; 987 } 988 989 pdevinfo.name = "gpio-sim"; 990 pdevinfo.fwnode = swnode; 991 pdevinfo.id = dev->id; 992 993 ret = dev_sync_probe_register(&dev->probe_data, &pdevinfo); 994 if (ret) { 995 gpio_sim_remove_hogs(dev); 996 gpio_sim_remove_swnode_recursive(swnode); 997 return ret; 998 } 999 1000 return 0; 1001 } 1002 1003 static void gpio_sim_device_deactivate(struct gpio_sim_device *dev) 1004 { 1005 struct fwnode_handle *swnode; 1006 1007 lockdep_assert_held(&dev->lock); 1008 1009 swnode = dev_fwnode(&dev->probe_data.pdev->dev); 1010 dev_sync_probe_unregister(&dev->probe_data); 1011 gpio_sim_remove_hogs(dev); 1012 gpio_sim_remove_swnode_recursive(swnode); 1013 } 1014 1015 static void 1016 gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock) 1017 { 1018 struct configfs_subsystem *subsys = dev->group.cg_subsys; 1019 struct gpio_sim_bank *bank; 1020 struct gpio_sim_line *line; 1021 struct config_item *item; 1022 1023 /* 1024 * The device only needs to depend on leaf entries. This is 1025 * sufficient to lock up all the configfs entries that the 1026 * instantiated, alive device depends on. 1027 */ 1028 list_for_each_entry(bank, &dev->bank_list, siblings) { 1029 list_for_each_entry(line, &bank->line_list, siblings) { 1030 item = line->hog ? &line->hog->item 1031 : &line->group.cg_item; 1032 1033 if (lock) 1034 WARN_ON(configfs_depend_item_unlocked(subsys, 1035 item)); 1036 else 1037 configfs_undepend_item_unlocked(item); 1038 } 1039 } 1040 } 1041 1042 static ssize_t 1043 gpio_sim_device_config_live_store(struct config_item *item, 1044 const char *page, size_t count) 1045 { 1046 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1047 bool live; 1048 int ret; 1049 1050 ret = kstrtobool(page, &live); 1051 if (ret) 1052 return ret; 1053 1054 if (live) 1055 gpio_sim_device_lockup_configfs(dev, true); 1056 1057 scoped_guard(mutex, &dev->lock) { 1058 if (live == gpio_sim_device_is_live(dev)) 1059 ret = -EPERM; 1060 else if (live) 1061 ret = gpio_sim_device_activate(dev); 1062 else 1063 gpio_sim_device_deactivate(dev); 1064 } 1065 1066 /* 1067 * Undepend is required only if device disablement (live == 0) 1068 * succeeds or if device enablement (live == 1) fails. 1069 */ 1070 if (live == !!ret) 1071 gpio_sim_device_lockup_configfs(dev, false); 1072 1073 return ret ?: count; 1074 } 1075 1076 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1077 1078 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1079 &gpio_sim_device_config_attr_dev_name, 1080 &gpio_sim_device_config_attr_live, 1081 NULL 1082 }; 1083 1084 struct gpio_sim_chip_name_ctx { 1085 struct fwnode_handle *swnode; 1086 char *page; 1087 }; 1088 1089 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1090 { 1091 struct gpio_sim_chip_name_ctx *ctx = data; 1092 1093 /* This would be the sysfs device exported in /sys/class/gpio. */ 1094 if (dev->class) 1095 return 0; 1096 1097 if (device_match_fwnode(dev, ctx->swnode)) 1098 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1099 1100 return 0; 1101 } 1102 1103 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1104 char *page) 1105 { 1106 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1107 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1108 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1109 1110 guard(mutex)(&dev->lock); 1111 1112 if (gpio_sim_device_is_live(dev)) 1113 return device_for_each_child(&dev->probe_data.pdev->dev, &ctx, 1114 gpio_sim_emit_chip_name); 1115 1116 return sprintf(page, "none\n"); 1117 } 1118 1119 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1120 1121 static ssize_t 1122 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1123 { 1124 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1125 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1126 1127 guard(mutex)(&dev->lock); 1128 1129 return sprintf(page, "%s\n", bank->label ?: ""); 1130 } 1131 1132 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1133 const char *page, size_t count) 1134 { 1135 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1136 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1137 char *trimmed; 1138 1139 guard(mutex)(&dev->lock); 1140 1141 if (gpio_sim_device_is_live(dev)) 1142 return -EBUSY; 1143 1144 trimmed = gpio_sim_strdup_trimmed(page, count); 1145 if (!trimmed) 1146 return -ENOMEM; 1147 1148 kfree(bank->label); 1149 bank->label = trimmed; 1150 1151 return count; 1152 } 1153 1154 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1155 1156 static ssize_t 1157 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1158 { 1159 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1160 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1161 1162 guard(mutex)(&dev->lock); 1163 1164 return sprintf(page, "%u\n", bank->num_lines); 1165 } 1166 1167 static ssize_t 1168 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1169 const char *page, size_t count) 1170 { 1171 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1172 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1173 unsigned int num_lines; 1174 int ret; 1175 1176 ret = kstrtouint(page, 0, &num_lines); 1177 if (ret) 1178 return ret; 1179 1180 if (num_lines == 0) 1181 return -EINVAL; 1182 1183 guard(mutex)(&dev->lock); 1184 1185 if (gpio_sim_device_is_live(dev)) 1186 return -EBUSY; 1187 1188 bank->num_lines = num_lines; 1189 1190 return count; 1191 } 1192 1193 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1194 1195 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1196 &gpio_sim_bank_config_attr_chip_name, 1197 &gpio_sim_bank_config_attr_label, 1198 &gpio_sim_bank_config_attr_num_lines, 1199 NULL 1200 }; 1201 1202 static ssize_t 1203 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1204 { 1205 struct gpio_sim_line *line = to_gpio_sim_line(item); 1206 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1207 1208 guard(mutex)(&dev->lock); 1209 1210 return sprintf(page, "%s\n", line->name ?: ""); 1211 } 1212 1213 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1214 const char *page, size_t count) 1215 { 1216 struct gpio_sim_line *line = to_gpio_sim_line(item); 1217 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1218 char *trimmed; 1219 1220 guard(mutex)(&dev->lock); 1221 1222 if (gpio_sim_device_is_live(dev)) 1223 return -EBUSY; 1224 1225 trimmed = gpio_sim_strdup_trimmed(page, count); 1226 if (!trimmed) 1227 return -ENOMEM; 1228 1229 kfree(line->name); 1230 line->name = trimmed; 1231 1232 return count; 1233 } 1234 1235 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1236 1237 static ssize_t 1238 gpio_sim_line_config_valid_show(struct config_item *item, char *page) 1239 { 1240 struct gpio_sim_line *line = to_gpio_sim_line(item); 1241 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1242 1243 guard(mutex)(&dev->lock); 1244 1245 return sprintf(page, "%c\n", line->valid ? '1' : '0'); 1246 } 1247 1248 static ssize_t gpio_sim_line_config_valid_store(struct config_item *item, 1249 const char *page, size_t count) 1250 { 1251 struct gpio_sim_line *line = to_gpio_sim_line(item); 1252 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1253 bool valid; 1254 int ret; 1255 1256 ret = kstrtobool(page, &valid); 1257 if (ret) 1258 return ret; 1259 1260 guard(mutex)(&dev->lock); 1261 1262 line->valid = valid; 1263 1264 return count; 1265 } 1266 1267 CONFIGFS_ATTR(gpio_sim_line_config_, valid); 1268 1269 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1270 &gpio_sim_line_config_attr_name, 1271 &gpio_sim_line_config_attr_valid, 1272 NULL 1273 }; 1274 1275 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1276 char *page) 1277 { 1278 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1279 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1280 1281 guard(mutex)(&dev->lock); 1282 1283 return sprintf(page, "%s\n", hog->name ?: ""); 1284 } 1285 1286 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1287 const char *page, size_t count) 1288 { 1289 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1290 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1291 char *trimmed; 1292 1293 guard(mutex)(&dev->lock); 1294 1295 if (gpio_sim_device_is_live(dev)) 1296 return -EBUSY; 1297 1298 trimmed = gpio_sim_strdup_trimmed(page, count); 1299 if (!trimmed) 1300 return -ENOMEM; 1301 1302 kfree(hog->name); 1303 hog->name = trimmed; 1304 1305 return count; 1306 } 1307 1308 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1309 1310 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1311 char *page) 1312 { 1313 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1314 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1315 char *repr; 1316 int dir; 1317 1318 scoped_guard(mutex, &dev->lock) 1319 dir = hog->dir; 1320 1321 switch (dir) { 1322 case GPIOD_IN: 1323 repr = "input"; 1324 break; 1325 case GPIOD_OUT_HIGH: 1326 repr = "output-high"; 1327 break; 1328 case GPIOD_OUT_LOW: 1329 repr = "output-low"; 1330 break; 1331 default: 1332 /* This would be a programmer bug. */ 1333 WARN(1, "Unexpected hog direction value: %d", dir); 1334 return -EINVAL; 1335 } 1336 1337 return sprintf(page, "%s\n", repr); 1338 } 1339 1340 static ssize_t 1341 gpio_sim_hog_config_direction_store(struct config_item *item, 1342 const char *page, size_t count) 1343 { 1344 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1345 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1346 int dir; 1347 1348 guard(mutex)(&dev->lock); 1349 1350 if (gpio_sim_device_is_live(dev)) 1351 return -EBUSY; 1352 1353 if (sysfs_streq(page, "input")) 1354 dir = GPIOD_IN; 1355 else if (sysfs_streq(page, "output-high")) 1356 dir = GPIOD_OUT_HIGH; 1357 else if (sysfs_streq(page, "output-low")) 1358 dir = GPIOD_OUT_LOW; 1359 else 1360 return -EINVAL; 1361 1362 hog->dir = dir; 1363 1364 return count; 1365 } 1366 1367 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1368 1369 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1370 &gpio_sim_hog_config_attr_name, 1371 &gpio_sim_hog_config_attr_direction, 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 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(sizeof(*hog), GFP_KERNEL); 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 struct configfs_item_operations gpio_sim_line_config_item_ops = { 1438 .release = gpio_sim_line_config_group_release, 1439 }; 1440 1441 static 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(sizeof(*line), GFP_KERNEL); 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 struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1499 .release = gpio_sim_bank_config_group_release, 1500 }; 1501 1502 static 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(sizeof(*bank), GFP_KERNEL); 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 struct configfs_item_operations gpio_sim_device_config_item_ops = { 1554 .release = gpio_sim_device_config_group_release, 1555 }; 1556 1557 static 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(sizeof(*dev), 1574 GFP_KERNEL); 1575 if (!dev) 1576 return ERR_PTR(-ENOMEM); 1577 1578 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1579 if (id < 0) 1580 return ERR_PTR(id); 1581 1582 config_group_init_type_name(&dev->group, name, 1583 &gpio_sim_device_config_group_type); 1584 dev->id = id; 1585 mutex_init(&dev->lock); 1586 INIT_LIST_HEAD(&dev->bank_list); 1587 1588 dev_sync_probe_init(&dev->probe_data); 1589 1590 return &no_free_ptr(dev)->group; 1591 } 1592 1593 static struct configfs_group_operations gpio_sim_config_group_ops = { 1594 .make_group = gpio_sim_config_make_device_group, 1595 }; 1596 1597 static const struct config_item_type gpio_sim_config_type = { 1598 .ct_group_ops = &gpio_sim_config_group_ops, 1599 .ct_owner = THIS_MODULE, 1600 }; 1601 1602 static struct configfs_subsystem gpio_sim_config_subsys = { 1603 .su_group = { 1604 .cg_item = { 1605 .ci_namebuf = "gpio-sim", 1606 .ci_type = &gpio_sim_config_type, 1607 }, 1608 }, 1609 }; 1610 1611 static int __init gpio_sim_init(void) 1612 { 1613 int ret; 1614 1615 ret = platform_driver_register(&gpio_sim_driver); 1616 if (ret) { 1617 pr_err("Error %d while registering the platform driver\n", ret); 1618 return ret; 1619 } 1620 1621 config_group_init(&gpio_sim_config_subsys.su_group); 1622 mutex_init(&gpio_sim_config_subsys.su_mutex); 1623 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1624 if (ret) { 1625 pr_err("Error %d while registering the configfs subsystem %s\n", 1626 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1627 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1628 platform_driver_unregister(&gpio_sim_driver); 1629 return ret; 1630 } 1631 1632 return 0; 1633 } 1634 module_init(gpio_sim_init); 1635 1636 static void __exit gpio_sim_exit(void) 1637 { 1638 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1639 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1640 platform_driver_unregister(&gpio_sim_driver); 1641 } 1642 module_exit(gpio_sim_exit); 1643 1644 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); 1645 MODULE_DESCRIPTION("GPIO Simulator Module"); 1646 MODULE_LICENSE("GPL"); 1647