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/completion.h> 14 #include <linux/configfs.h> 15 #include <linux/device.h> 16 #include <linux/err.h> 17 #include <linux/gpio/consumer.h> 18 #include <linux/gpio/driver.h> 19 #include <linux/gpio/machine.h> 20 #include <linux/idr.h> 21 #include <linux/interrupt.h> 22 #include <linux/irq.h> 23 #include <linux/irq_sim.h> 24 #include <linux/list.h> 25 #include <linux/lockdep.h> 26 #include <linux/minmax.h> 27 #include <linux/mod_devicetable.h> 28 #include <linux/module.h> 29 #include <linux/mutex.h> 30 #include <linux/notifier.h> 31 #include <linux/platform_device.h> 32 #include <linux/property.h> 33 #include <linux/seq_file.h> 34 #include <linux/slab.h> 35 #include <linux/string.h> 36 #include <linux/string_helpers.h> 37 #include <linux/sysfs.h> 38 #include <linux/types.h> 39 40 #define GPIO_SIM_NGPIO_MAX 1024 41 #define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */ 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 void 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 } 129 130 static int gpio_sim_get_multiple(struct gpio_chip *gc, 131 unsigned long *mask, unsigned long *bits) 132 { 133 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 134 135 scoped_guard(mutex, &chip->lock) 136 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 137 138 return 0; 139 } 140 141 static void gpio_sim_set_multiple(struct gpio_chip *gc, 142 unsigned long *mask, unsigned long *bits) 143 { 144 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 145 146 scoped_guard(mutex, &chip->lock) 147 bitmap_replace(chip->value_map, chip->value_map, bits, mask, 148 gc->ngpio); 149 } 150 151 static int gpio_sim_direction_output(struct gpio_chip *gc, 152 unsigned int offset, int value) 153 { 154 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 155 156 scoped_guard(mutex, &chip->lock) { 157 __clear_bit(offset, chip->direction_map); 158 __assign_bit(offset, chip->value_map, value); 159 } 160 161 return 0; 162 } 163 164 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 165 { 166 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 167 168 scoped_guard(mutex, &chip->lock) 169 __set_bit(offset, chip->direction_map); 170 171 return 0; 172 } 173 174 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 175 { 176 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 177 int direction; 178 179 scoped_guard(mutex, &chip->lock) 180 direction = !!test_bit(offset, chip->direction_map); 181 182 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; 183 } 184 185 static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset, 186 unsigned long config) 187 { 188 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 189 190 switch (pinconf_to_config_param(config)) { 191 case PIN_CONFIG_BIAS_PULL_UP: 192 return gpio_sim_apply_pull(chip, offset, 1); 193 case PIN_CONFIG_BIAS_PULL_DOWN: 194 return gpio_sim_apply_pull(chip, offset, 0); 195 default: 196 break; 197 } 198 199 return -ENOTSUPP; 200 } 201 202 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 203 { 204 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 205 206 return irq_create_mapping(chip->irq_sim, offset); 207 } 208 209 static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset) 210 { 211 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 212 213 scoped_guard(mutex, &chip->lock) 214 __set_bit(offset, chip->request_map); 215 216 return 0; 217 } 218 219 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 220 { 221 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 222 223 scoped_guard(mutex, &chip->lock) { 224 __assign_bit(offset, chip->value_map, 225 !!test_bit(offset, chip->pull_map)); 226 __clear_bit(offset, chip->request_map); 227 } 228 } 229 230 static int gpio_sim_irq_requested(struct irq_domain *domain, 231 irq_hw_number_t hwirq, void *data) 232 { 233 struct gpio_sim_chip *chip = data; 234 235 return gpiochip_lock_as_irq(&chip->gc, hwirq); 236 } 237 238 static void gpio_sim_irq_released(struct irq_domain *domain, 239 irq_hw_number_t hwirq, void *data) 240 { 241 struct gpio_sim_chip *chip = data; 242 243 gpiochip_unlock_as_irq(&chip->gc, hwirq); 244 } 245 246 static const struct irq_sim_ops gpio_sim_irq_sim_ops = { 247 .irq_sim_irq_requested = gpio_sim_irq_requested, 248 .irq_sim_irq_released = gpio_sim_irq_released, 249 }; 250 251 static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc) 252 { 253 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 254 const char *label; 255 int i; 256 257 guard(mutex)(&chip->lock); 258 259 for_each_hwgpio(gc, i, label) 260 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n", 261 gc->base + i, 262 label ?: "<unused>", 263 test_bit(i, chip->direction_map) ? "input" : 264 test_bit(i, chip->value_map) ? "output-high" : 265 "output-low", 266 test_bit(i, chip->pull_map) ? "pull-up" : 267 "pull-down"); 268 } 269 270 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 271 struct device_attribute *attr, char *buf) 272 { 273 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 274 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 275 int val; 276 277 scoped_guard(mutex, &chip->lock) 278 val = !!test_bit(line_attr->offset, chip->value_map); 279 280 return sysfs_emit(buf, "%d\n", val); 281 } 282 283 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 284 struct device_attribute *attr, 285 const char *buf, size_t count) 286 { 287 /* 288 * Not assigning this function will result in write() returning -EIO 289 * which is confusing. Return -EPERM explicitly. 290 */ 291 return -EPERM; 292 } 293 294 static const char *const gpio_sim_sysfs_pull_strings[] = { 295 [0] = "pull-down", 296 [1] = "pull-up", 297 }; 298 299 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 300 struct device_attribute *attr, 301 char *buf) 302 { 303 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 304 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 305 int pull; 306 307 scoped_guard(mutex, &chip->lock) 308 pull = !!test_bit(line_attr->offset, chip->pull_map); 309 310 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 311 } 312 313 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 314 struct device_attribute *attr, 315 const char *buf, size_t len) 316 { 317 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 318 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 319 int ret, pull; 320 321 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 322 if (pull < 0) 323 return pull; 324 325 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 326 if (ret) 327 return ret; 328 329 return len; 330 } 331 332 static void gpio_sim_put_device(void *data) 333 { 334 struct device *dev = data; 335 336 put_device(dev); 337 } 338 339 static void gpio_sim_dispose_mappings(void *data) 340 { 341 struct gpio_sim_chip *chip = data; 342 unsigned int i; 343 344 for (i = 0; i < chip->gc.ngpio; i++) 345 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 346 } 347 348 static void gpio_sim_sysfs_remove(void *data) 349 { 350 struct gpio_sim_chip *chip = data; 351 352 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups); 353 } 354 355 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 356 { 357 struct device_attribute *val_dev_attr, *pull_dev_attr; 358 struct gpio_sim_attribute *val_attr, *pull_attr; 359 unsigned int num_lines = chip->gc.ngpio; 360 struct device *dev = chip->gc.parent; 361 struct attribute_group *attr_group; 362 struct attribute **attrs; 363 int i, ret; 364 365 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 366 num_lines + 1, GFP_KERNEL); 367 if (!chip->attr_groups) 368 return -ENOMEM; 369 370 for (i = 0; i < num_lines; i++) { 371 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 372 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 373 GFP_KERNEL); 374 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 375 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 376 if (!attr_group || !attrs || !val_attr || !pull_attr) 377 return -ENOMEM; 378 379 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 380 "sim_gpio%u", i); 381 if (!attr_group->name) 382 return -ENOMEM; 383 384 val_attr->offset = pull_attr->offset = i; 385 386 val_dev_attr = &val_attr->dev_attr; 387 pull_dev_attr = &pull_attr->dev_attr; 388 389 sysfs_attr_init(&val_dev_attr->attr); 390 sysfs_attr_init(&pull_dev_attr->attr); 391 392 val_dev_attr->attr.name = "value"; 393 pull_dev_attr->attr.name = "pull"; 394 395 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 396 397 val_dev_attr->show = gpio_sim_sysfs_val_show; 398 val_dev_attr->store = gpio_sim_sysfs_val_store; 399 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 400 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 401 402 attrs[0] = &val_dev_attr->attr; 403 attrs[1] = &pull_dev_attr->attr; 404 405 attr_group->attrs = attrs; 406 chip->attr_groups[i] = attr_group; 407 } 408 409 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups); 410 if (ret) 411 return ret; 412 413 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 414 } 415 416 static int gpio_sim_dev_match_fwnode(struct device *dev, void *data) 417 { 418 return device_match_fwnode(dev, data); 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, gpio_sim_dev_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 config_group group; 550 551 /* 552 * If pdev is NULL, the device is 'pending' (waiting for configuration). 553 * Once the pointer is assigned, the device has been created and the 554 * item is 'live'. 555 */ 556 struct platform_device *pdev; 557 int id; 558 559 /* 560 * Each configfs filesystem operation is protected with the subsystem 561 * mutex. Each separate attribute is protected with the buffer mutex. 562 * This structure however can be modified by callbacks of different 563 * attributes so we need another lock. 564 * 565 * We use this lock for protecting all data structures owned by this 566 * object too. 567 */ 568 struct mutex lock; 569 570 /* 571 * This is used to synchronously wait for the driver's probe to complete 572 * and notify the user-space about any errors. 573 */ 574 struct notifier_block bus_notifier; 575 struct completion probe_completion; 576 bool driver_bound; 577 578 struct gpiod_hog *hogs; 579 580 struct list_head bank_list; 581 }; 582 583 /* This is called with dev->lock already taken. */ 584 static int gpio_sim_bus_notifier_call(struct notifier_block *nb, 585 unsigned long action, void *data) 586 { 587 struct gpio_sim_device *simdev = container_of(nb, 588 struct gpio_sim_device, 589 bus_notifier); 590 struct device *dev = data; 591 char devname[32]; 592 593 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id); 594 595 if (!device_match_name(dev, devname)) 596 return NOTIFY_DONE; 597 598 if (action == BUS_NOTIFY_BOUND_DRIVER) 599 simdev->driver_bound = true; 600 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND) 601 simdev->driver_bound = false; 602 else 603 return NOTIFY_DONE; 604 605 complete(&simdev->probe_completion); 606 607 return NOTIFY_OK; 608 } 609 610 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 611 { 612 struct config_group *group = to_config_group(item); 613 614 return container_of(group, struct gpio_sim_device, group); 615 } 616 617 struct gpio_sim_bank { 618 struct config_group group; 619 620 /* 621 * We could have used the ci_parent field of the config_item but 622 * configfs is stupid and calls the item's release callback after 623 * already having cleared the parent pointer even though the parent 624 * is guaranteed to survive the child... 625 * 626 * So we need to store the pointer to the parent struct here. We can 627 * dereference it anywhere we need with no checks and no locking as 628 * it's guaranteed to survive the children and protected by configfs 629 * locks. 630 * 631 * Same for other structures. 632 */ 633 struct gpio_sim_device *parent; 634 struct list_head siblings; 635 636 char *label; 637 unsigned int num_lines; 638 639 struct list_head line_list; 640 641 struct fwnode_handle *swnode; 642 }; 643 644 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 645 { 646 struct config_group *group = to_config_group(item); 647 648 return container_of(group, struct gpio_sim_bank, group); 649 } 650 651 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 652 { 653 return bank->label && *bank->label; 654 } 655 656 static struct gpio_sim_device * 657 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 658 { 659 return bank->parent; 660 } 661 662 struct gpio_sim_hog; 663 664 struct gpio_sim_line { 665 struct config_group group; 666 667 struct gpio_sim_bank *parent; 668 struct list_head siblings; 669 670 unsigned int offset; 671 char *name; 672 673 /* There can only be one hog per line. */ 674 struct gpio_sim_hog *hog; 675 }; 676 677 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 678 { 679 struct config_group *group = to_config_group(item); 680 681 return container_of(group, struct gpio_sim_line, group); 682 } 683 684 static struct gpio_sim_device * 685 gpio_sim_line_get_device(struct gpio_sim_line *line) 686 { 687 struct gpio_sim_bank *bank = line->parent; 688 689 return gpio_sim_bank_get_device(bank); 690 } 691 692 struct gpio_sim_hog { 693 struct config_item item; 694 struct gpio_sim_line *parent; 695 696 char *name; 697 int dir; 698 }; 699 700 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 701 { 702 return container_of(item, struct gpio_sim_hog, item); 703 } 704 705 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 706 { 707 struct gpio_sim_line *line = hog->parent; 708 709 return gpio_sim_line_get_device(line); 710 } 711 712 static bool gpio_sim_device_is_live(struct gpio_sim_device *dev) 713 { 714 lockdep_assert_held(&dev->lock); 715 716 return !!dev->pdev; 717 } 718 719 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 720 { 721 char *trimmed; 722 723 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 724 if (!trimmed) 725 return NULL; 726 727 return strim(trimmed); 728 } 729 730 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 731 char *page) 732 { 733 struct gpio_sim_device *dev = to_gpio_sim_device(item); 734 struct platform_device *pdev; 735 736 guard(mutex)(&dev->lock); 737 738 pdev = dev->pdev; 739 if (pdev) 740 return sprintf(page, "%s\n", dev_name(&pdev->dev)); 741 742 return sprintf(page, "gpio-sim.%d\n", dev->id); 743 } 744 745 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 746 747 static ssize_t 748 gpio_sim_device_config_live_show(struct config_item *item, char *page) 749 { 750 struct gpio_sim_device *dev = to_gpio_sim_device(item); 751 bool live; 752 753 scoped_guard(mutex, &dev->lock) 754 live = gpio_sim_device_is_live(dev); 755 756 return sprintf(page, "%c\n", live ? '1' : '0'); 757 } 758 759 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank) 760 { 761 struct gpio_sim_line *line; 762 unsigned int size = 0; 763 764 list_for_each_entry(line, &bank->line_list, siblings) { 765 if (!line->name || (line->offset >= bank->num_lines)) 766 continue; 767 768 size = max(size, line->offset + 1); 769 } 770 771 return size; 772 } 773 774 static void 775 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 776 { 777 struct gpio_sim_line *line; 778 779 list_for_each_entry(line, &bank->line_list, siblings) { 780 if (!line->name || (line->offset >= bank->num_lines)) 781 continue; 782 783 line_names[line->offset] = line->name; 784 } 785 } 786 787 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 788 { 789 struct gpiod_hog *hog; 790 791 if (!dev->hogs) 792 return; 793 794 gpiod_remove_hogs(dev->hogs); 795 796 for (hog = dev->hogs; hog->chip_label; hog++) { 797 kfree(hog->chip_label); 798 kfree(hog->line_name); 799 } 800 801 kfree(dev->hogs); 802 dev->hogs = NULL; 803 } 804 805 static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 806 { 807 unsigned int num_hogs = 0, idx = 0; 808 struct gpio_sim_bank *bank; 809 struct gpio_sim_line *line; 810 struct gpiod_hog *hog; 811 812 list_for_each_entry(bank, &dev->bank_list, siblings) { 813 list_for_each_entry(line, &bank->line_list, siblings) { 814 if (line->offset >= bank->num_lines) 815 continue; 816 817 if (line->hog) 818 num_hogs++; 819 } 820 } 821 822 if (!num_hogs) 823 return 0; 824 825 /* Allocate one more for the sentinel. */ 826 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 827 if (!dev->hogs) 828 return -ENOMEM; 829 830 list_for_each_entry(bank, &dev->bank_list, siblings) { 831 list_for_each_entry(line, &bank->line_list, siblings) { 832 if (line->offset >= bank->num_lines) 833 continue; 834 835 if (!line->hog) 836 continue; 837 838 hog = &dev->hogs[idx++]; 839 840 /* 841 * We need to make this string manually because at this 842 * point the device doesn't exist yet and so dev_name() 843 * is not available. 844 */ 845 if (gpio_sim_bank_has_label(bank)) 846 hog->chip_label = kstrdup(bank->label, 847 GFP_KERNEL); 848 else 849 hog->chip_label = kasprintf(GFP_KERNEL, 850 "gpio-sim.%u:%pfwP", 851 dev->id, 852 bank->swnode); 853 if (!hog->chip_label) { 854 gpio_sim_remove_hogs(dev); 855 return -ENOMEM; 856 } 857 858 /* 859 * We need to duplicate this because the hog config 860 * item can be removed at any time (and we can't block 861 * it) and gpiolib doesn't make a deep copy of the hog 862 * data. 863 */ 864 if (line->hog->name) { 865 hog->line_name = kstrdup(line->hog->name, 866 GFP_KERNEL); 867 if (!hog->line_name) { 868 gpio_sim_remove_hogs(dev); 869 return -ENOMEM; 870 } 871 } 872 873 hog->chip_hwnum = line->offset; 874 hog->dflags = line->hog->dir; 875 } 876 } 877 878 gpiod_add_hogs(dev->hogs); 879 880 return 0; 881 } 882 883 static struct fwnode_handle * 884 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 885 struct fwnode_handle *parent) 886 { 887 struct property_entry properties[GPIO_SIM_PROP_MAX]; 888 unsigned int prop_idx = 0, line_names_size; 889 char **line_names __free(kfree) = NULL; 890 891 memset(properties, 0, sizeof(properties)); 892 893 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 894 895 if (gpio_sim_bank_has_label(bank)) 896 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 897 bank->label); 898 899 line_names_size = gpio_sim_get_line_names_size(bank); 900 if (line_names_size) { 901 line_names = kcalloc(line_names_size, sizeof(*line_names), 902 GFP_KERNEL); 903 if (!line_names) 904 return ERR_PTR(-ENOMEM); 905 906 gpio_sim_set_line_names(bank, line_names); 907 908 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 909 "gpio-line-names", 910 line_names, line_names_size); 911 } 912 913 return fwnode_create_software_node(properties, parent); 914 } 915 916 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 917 { 918 struct fwnode_handle *child; 919 920 fwnode_for_each_child_node(swnode, child) 921 fwnode_remove_software_node(child); 922 923 fwnode_remove_software_node(swnode); 924 } 925 926 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 927 { 928 struct gpio_sim_bank *this, *pos; 929 930 list_for_each_entry(this, &dev->bank_list, siblings) { 931 list_for_each_entry(pos, &dev->bank_list, siblings) { 932 if (this == pos || (!this->label || !pos->label)) 933 continue; 934 935 if (strcmp(this->label, pos->label) == 0) 936 return true; 937 } 938 } 939 940 return false; 941 } 942 943 static int gpio_sim_device_activate(struct gpio_sim_device *dev) 944 { 945 struct platform_device_info pdevinfo; 946 struct fwnode_handle *swnode; 947 struct platform_device *pdev; 948 struct gpio_sim_bank *bank; 949 int ret; 950 951 lockdep_assert_held(&dev->lock); 952 953 if (list_empty(&dev->bank_list)) 954 return -ENODATA; 955 956 /* 957 * Non-unique GPIO device labels are a corner-case we don't support 958 * as it would interfere with machine hogging mechanism and has little 959 * use in real life. 960 */ 961 if (gpio_sim_bank_labels_non_unique(dev)) 962 return -EINVAL; 963 964 memset(&pdevinfo, 0, sizeof(pdevinfo)); 965 966 swnode = fwnode_create_software_node(NULL, NULL); 967 if (IS_ERR(swnode)) 968 return PTR_ERR(swnode); 969 970 list_for_each_entry(bank, &dev->bank_list, siblings) { 971 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 972 if (IS_ERR(bank->swnode)) { 973 ret = PTR_ERR(bank->swnode); 974 gpio_sim_remove_swnode_recursive(swnode); 975 return ret; 976 } 977 } 978 979 ret = gpio_sim_add_hogs(dev); 980 if (ret) { 981 gpio_sim_remove_swnode_recursive(swnode); 982 return ret; 983 } 984 985 pdevinfo.name = "gpio-sim"; 986 pdevinfo.fwnode = swnode; 987 pdevinfo.id = dev->id; 988 989 reinit_completion(&dev->probe_completion); 990 dev->driver_bound = false; 991 bus_register_notifier(&platform_bus_type, &dev->bus_notifier); 992 993 pdev = platform_device_register_full(&pdevinfo); 994 if (IS_ERR(pdev)) { 995 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 996 gpio_sim_remove_hogs(dev); 997 gpio_sim_remove_swnode_recursive(swnode); 998 return PTR_ERR(pdev); 999 } 1000 1001 wait_for_completion(&dev->probe_completion); 1002 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 1003 1004 if (!dev->driver_bound) { 1005 /* Probe failed, check kernel log. */ 1006 platform_device_unregister(pdev); 1007 gpio_sim_remove_hogs(dev); 1008 gpio_sim_remove_swnode_recursive(swnode); 1009 return -ENXIO; 1010 } 1011 1012 dev->pdev = pdev; 1013 1014 return 0; 1015 } 1016 1017 static void gpio_sim_device_deactivate(struct gpio_sim_device *dev) 1018 { 1019 struct fwnode_handle *swnode; 1020 1021 lockdep_assert_held(&dev->lock); 1022 1023 swnode = dev_fwnode(&dev->pdev->dev); 1024 platform_device_unregister(dev->pdev); 1025 gpio_sim_remove_hogs(dev); 1026 gpio_sim_remove_swnode_recursive(swnode); 1027 dev->pdev = NULL; 1028 } 1029 1030 static void 1031 gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock) 1032 { 1033 struct configfs_subsystem *subsys = dev->group.cg_subsys; 1034 struct gpio_sim_bank *bank; 1035 struct gpio_sim_line *line; 1036 1037 /* 1038 * The device only needs to depend on leaf line entries. This is 1039 * sufficient to lock up all the configfs entries that the 1040 * instantiated, alive device depends on. 1041 */ 1042 list_for_each_entry(bank, &dev->bank_list, siblings) { 1043 list_for_each_entry(line, &bank->line_list, siblings) { 1044 if (lock) 1045 WARN_ON(configfs_depend_item_unlocked( 1046 subsys, &line->group.cg_item)); 1047 else 1048 configfs_undepend_item_unlocked( 1049 &line->group.cg_item); 1050 } 1051 } 1052 } 1053 1054 static ssize_t 1055 gpio_sim_device_config_live_store(struct config_item *item, 1056 const char *page, size_t count) 1057 { 1058 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1059 bool live; 1060 int ret; 1061 1062 ret = kstrtobool(page, &live); 1063 if (ret) 1064 return ret; 1065 1066 if (live) 1067 gpio_sim_device_lockup_configfs(dev, true); 1068 1069 scoped_guard(mutex, &dev->lock) { 1070 if (live == gpio_sim_device_is_live(dev)) 1071 ret = -EPERM; 1072 else if (live) 1073 ret = gpio_sim_device_activate(dev); 1074 else 1075 gpio_sim_device_deactivate(dev); 1076 } 1077 1078 /* 1079 * Undepend is required only if device disablement (live == 0) 1080 * succeeds or if device enablement (live == 1) fails. 1081 */ 1082 if (live == !!ret) 1083 gpio_sim_device_lockup_configfs(dev, false); 1084 1085 return ret ?: count; 1086 } 1087 1088 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1089 1090 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1091 &gpio_sim_device_config_attr_dev_name, 1092 &gpio_sim_device_config_attr_live, 1093 NULL 1094 }; 1095 1096 struct gpio_sim_chip_name_ctx { 1097 struct fwnode_handle *swnode; 1098 char *page; 1099 }; 1100 1101 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1102 { 1103 struct gpio_sim_chip_name_ctx *ctx = data; 1104 1105 /* This would be the sysfs device exported in /sys/class/gpio. */ 1106 if (dev->class) 1107 return 0; 1108 1109 if (device_match_fwnode(dev, ctx->swnode)) 1110 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1111 1112 return 0; 1113 } 1114 1115 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1116 char *page) 1117 { 1118 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1119 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1120 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1121 1122 guard(mutex)(&dev->lock); 1123 1124 if (gpio_sim_device_is_live(dev)) 1125 return device_for_each_child(&dev->pdev->dev, &ctx, 1126 gpio_sim_emit_chip_name); 1127 1128 return sprintf(page, "none\n"); 1129 } 1130 1131 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1132 1133 static ssize_t 1134 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1135 { 1136 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1137 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1138 1139 guard(mutex)(&dev->lock); 1140 1141 return sprintf(page, "%s\n", bank->label ?: ""); 1142 } 1143 1144 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1145 const char *page, size_t count) 1146 { 1147 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1148 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1149 char *trimmed; 1150 1151 guard(mutex)(&dev->lock); 1152 1153 if (gpio_sim_device_is_live(dev)) 1154 return -EBUSY; 1155 1156 trimmed = gpio_sim_strdup_trimmed(page, count); 1157 if (!trimmed) 1158 return -ENOMEM; 1159 1160 kfree(bank->label); 1161 bank->label = trimmed; 1162 1163 return count; 1164 } 1165 1166 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1167 1168 static ssize_t 1169 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 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 1174 guard(mutex)(&dev->lock); 1175 1176 return sprintf(page, "%u\n", bank->num_lines); 1177 } 1178 1179 static ssize_t 1180 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1181 const char *page, size_t count) 1182 { 1183 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1184 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1185 unsigned int num_lines; 1186 int ret; 1187 1188 ret = kstrtouint(page, 0, &num_lines); 1189 if (ret) 1190 return ret; 1191 1192 if (num_lines == 0) 1193 return -EINVAL; 1194 1195 guard(mutex)(&dev->lock); 1196 1197 if (gpio_sim_device_is_live(dev)) 1198 return -EBUSY; 1199 1200 bank->num_lines = num_lines; 1201 1202 return count; 1203 } 1204 1205 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1206 1207 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1208 &gpio_sim_bank_config_attr_chip_name, 1209 &gpio_sim_bank_config_attr_label, 1210 &gpio_sim_bank_config_attr_num_lines, 1211 NULL 1212 }; 1213 1214 static ssize_t 1215 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1216 { 1217 struct gpio_sim_line *line = to_gpio_sim_line(item); 1218 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1219 1220 guard(mutex)(&dev->lock); 1221 1222 return sprintf(page, "%s\n", line->name ?: ""); 1223 } 1224 1225 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1226 const char *page, size_t count) 1227 { 1228 struct gpio_sim_line *line = to_gpio_sim_line(item); 1229 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1230 char *trimmed; 1231 1232 guard(mutex)(&dev->lock); 1233 1234 if (gpio_sim_device_is_live(dev)) 1235 return -EBUSY; 1236 1237 trimmed = gpio_sim_strdup_trimmed(page, count); 1238 if (!trimmed) 1239 return -ENOMEM; 1240 1241 kfree(line->name); 1242 line->name = trimmed; 1243 1244 return count; 1245 } 1246 1247 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1248 1249 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1250 &gpio_sim_line_config_attr_name, 1251 NULL 1252 }; 1253 1254 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1255 char *page) 1256 { 1257 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1258 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1259 1260 guard(mutex)(&dev->lock); 1261 1262 return sprintf(page, "%s\n", hog->name ?: ""); 1263 } 1264 1265 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1266 const char *page, size_t count) 1267 { 1268 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1269 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1270 char *trimmed; 1271 1272 guard(mutex)(&dev->lock); 1273 1274 if (gpio_sim_device_is_live(dev)) 1275 return -EBUSY; 1276 1277 trimmed = gpio_sim_strdup_trimmed(page, count); 1278 if (!trimmed) 1279 return -ENOMEM; 1280 1281 kfree(hog->name); 1282 hog->name = trimmed; 1283 1284 return count; 1285 } 1286 1287 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1288 1289 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1290 char *page) 1291 { 1292 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1293 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1294 char *repr; 1295 int dir; 1296 1297 scoped_guard(mutex, &dev->lock) 1298 dir = hog->dir; 1299 1300 switch (dir) { 1301 case GPIOD_IN: 1302 repr = "input"; 1303 break; 1304 case GPIOD_OUT_HIGH: 1305 repr = "output-high"; 1306 break; 1307 case GPIOD_OUT_LOW: 1308 repr = "output-low"; 1309 break; 1310 default: 1311 /* This would be a programmer bug. */ 1312 WARN(1, "Unexpected hog direction value: %d", dir); 1313 return -EINVAL; 1314 } 1315 1316 return sprintf(page, "%s\n", repr); 1317 } 1318 1319 static ssize_t 1320 gpio_sim_hog_config_direction_store(struct config_item *item, 1321 const char *page, size_t count) 1322 { 1323 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1324 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1325 int dir; 1326 1327 guard(mutex)(&dev->lock); 1328 1329 if (gpio_sim_device_is_live(dev)) 1330 return -EBUSY; 1331 1332 if (sysfs_streq(page, "input")) 1333 dir = GPIOD_IN; 1334 else if (sysfs_streq(page, "output-high")) 1335 dir = GPIOD_OUT_HIGH; 1336 else if (sysfs_streq(page, "output-low")) 1337 dir = GPIOD_OUT_LOW; 1338 else 1339 return -EINVAL; 1340 1341 hog->dir = dir; 1342 1343 return count; 1344 } 1345 1346 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1347 1348 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1349 &gpio_sim_hog_config_attr_name, 1350 &gpio_sim_hog_config_attr_direction, 1351 NULL 1352 }; 1353 1354 static void gpio_sim_hog_config_item_release(struct config_item *item) 1355 { 1356 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1357 struct gpio_sim_line *line = hog->parent; 1358 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1359 1360 scoped_guard(mutex, &dev->lock) 1361 line->hog = NULL; 1362 1363 kfree(hog->name); 1364 kfree(hog); 1365 } 1366 1367 static struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1368 .release = gpio_sim_hog_config_item_release, 1369 }; 1370 1371 static const struct config_item_type gpio_sim_hog_config_type = { 1372 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1373 .ct_attrs = gpio_sim_hog_config_attrs, 1374 .ct_owner = THIS_MODULE, 1375 }; 1376 1377 static struct config_item * 1378 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1379 { 1380 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1381 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1382 struct gpio_sim_hog *hog; 1383 1384 if (strcmp(name, "hog") != 0) 1385 return ERR_PTR(-EINVAL); 1386 1387 guard(mutex)(&dev->lock); 1388 1389 hog = kzalloc(sizeof(*hog), GFP_KERNEL); 1390 if (!hog) 1391 return ERR_PTR(-ENOMEM); 1392 1393 config_item_init_type_name(&hog->item, name, 1394 &gpio_sim_hog_config_type); 1395 1396 hog->dir = GPIOD_IN; 1397 hog->name = NULL; 1398 hog->parent = line; 1399 line->hog = hog; 1400 1401 return &hog->item; 1402 } 1403 1404 static void gpio_sim_line_config_group_release(struct config_item *item) 1405 { 1406 struct gpio_sim_line *line = to_gpio_sim_line(item); 1407 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1408 1409 scoped_guard(mutex, &dev->lock) 1410 list_del(&line->siblings); 1411 1412 kfree(line->name); 1413 kfree(line); 1414 } 1415 1416 static struct configfs_item_operations gpio_sim_line_config_item_ops = { 1417 .release = gpio_sim_line_config_group_release, 1418 }; 1419 1420 static struct configfs_group_operations gpio_sim_line_config_group_ops = { 1421 .make_item = gpio_sim_line_config_make_hog_item, 1422 }; 1423 1424 static const struct config_item_type gpio_sim_line_config_type = { 1425 .ct_item_ops = &gpio_sim_line_config_item_ops, 1426 .ct_group_ops = &gpio_sim_line_config_group_ops, 1427 .ct_attrs = gpio_sim_line_config_attrs, 1428 .ct_owner = THIS_MODULE, 1429 }; 1430 1431 static struct config_group * 1432 gpio_sim_bank_config_make_line_group(struct config_group *group, 1433 const char *name) 1434 { 1435 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1436 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1437 struct gpio_sim_line *line; 1438 unsigned int offset; 1439 int ret, nchar; 1440 1441 ret = sscanf(name, "line%u%n", &offset, &nchar); 1442 if (ret != 1 || nchar != strlen(name)) 1443 return ERR_PTR(-EINVAL); 1444 1445 guard(mutex)(&dev->lock); 1446 1447 if (gpio_sim_device_is_live(dev)) 1448 return ERR_PTR(-EBUSY); 1449 1450 line = kzalloc(sizeof(*line), GFP_KERNEL); 1451 if (!line) 1452 return ERR_PTR(-ENOMEM); 1453 1454 config_group_init_type_name(&line->group, name, 1455 &gpio_sim_line_config_type); 1456 1457 line->parent = bank; 1458 line->offset = offset; 1459 list_add_tail(&line->siblings, &bank->line_list); 1460 1461 return &line->group; 1462 } 1463 1464 static void gpio_sim_bank_config_group_release(struct config_item *item) 1465 { 1466 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1467 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1468 1469 scoped_guard(mutex, &dev->lock) 1470 list_del(&bank->siblings); 1471 1472 kfree(bank->label); 1473 kfree(bank); 1474 } 1475 1476 static struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1477 .release = gpio_sim_bank_config_group_release, 1478 }; 1479 1480 static struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1481 .make_group = gpio_sim_bank_config_make_line_group, 1482 }; 1483 1484 static const struct config_item_type gpio_sim_bank_config_group_type = { 1485 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1486 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1487 .ct_attrs = gpio_sim_bank_config_attrs, 1488 .ct_owner = THIS_MODULE, 1489 }; 1490 1491 static struct config_group * 1492 gpio_sim_device_config_make_bank_group(struct config_group *group, 1493 const char *name) 1494 { 1495 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1496 struct gpio_sim_bank *bank; 1497 1498 guard(mutex)(&dev->lock); 1499 1500 if (gpio_sim_device_is_live(dev)) 1501 return ERR_PTR(-EBUSY); 1502 1503 bank = kzalloc(sizeof(*bank), GFP_KERNEL); 1504 if (!bank) 1505 return ERR_PTR(-ENOMEM); 1506 1507 config_group_init_type_name(&bank->group, name, 1508 &gpio_sim_bank_config_group_type); 1509 bank->num_lines = 1; 1510 bank->parent = dev; 1511 INIT_LIST_HEAD(&bank->line_list); 1512 list_add_tail(&bank->siblings, &dev->bank_list); 1513 1514 return &bank->group; 1515 } 1516 1517 static void gpio_sim_device_config_group_release(struct config_item *item) 1518 { 1519 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1520 1521 scoped_guard(mutex, &dev->lock) { 1522 if (gpio_sim_device_is_live(dev)) 1523 gpio_sim_device_deactivate(dev); 1524 } 1525 1526 mutex_destroy(&dev->lock); 1527 ida_free(&gpio_sim_ida, dev->id); 1528 kfree(dev); 1529 } 1530 1531 static struct configfs_item_operations gpio_sim_device_config_item_ops = { 1532 .release = gpio_sim_device_config_group_release, 1533 }; 1534 1535 static struct configfs_group_operations gpio_sim_device_config_group_ops = { 1536 .make_group = gpio_sim_device_config_make_bank_group, 1537 }; 1538 1539 static const struct config_item_type gpio_sim_device_config_group_type = { 1540 .ct_item_ops = &gpio_sim_device_config_item_ops, 1541 .ct_group_ops = &gpio_sim_device_config_group_ops, 1542 .ct_attrs = gpio_sim_device_config_attrs, 1543 .ct_owner = THIS_MODULE, 1544 }; 1545 1546 static struct config_group * 1547 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1548 { 1549 int id; 1550 1551 struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev), 1552 GFP_KERNEL); 1553 if (!dev) 1554 return ERR_PTR(-ENOMEM); 1555 1556 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1557 if (id < 0) 1558 return ERR_PTR(id); 1559 1560 config_group_init_type_name(&dev->group, name, 1561 &gpio_sim_device_config_group_type); 1562 dev->id = id; 1563 mutex_init(&dev->lock); 1564 INIT_LIST_HEAD(&dev->bank_list); 1565 1566 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call; 1567 init_completion(&dev->probe_completion); 1568 1569 return &no_free_ptr(dev)->group; 1570 } 1571 1572 static struct configfs_group_operations gpio_sim_config_group_ops = { 1573 .make_group = gpio_sim_config_make_device_group, 1574 }; 1575 1576 static const struct config_item_type gpio_sim_config_type = { 1577 .ct_group_ops = &gpio_sim_config_group_ops, 1578 .ct_owner = THIS_MODULE, 1579 }; 1580 1581 static struct configfs_subsystem gpio_sim_config_subsys = { 1582 .su_group = { 1583 .cg_item = { 1584 .ci_namebuf = "gpio-sim", 1585 .ci_type = &gpio_sim_config_type, 1586 }, 1587 }, 1588 }; 1589 1590 static int __init gpio_sim_init(void) 1591 { 1592 int ret; 1593 1594 ret = platform_driver_register(&gpio_sim_driver); 1595 if (ret) { 1596 pr_err("Error %d while registering the platform driver\n", ret); 1597 return ret; 1598 } 1599 1600 config_group_init(&gpio_sim_config_subsys.su_group); 1601 mutex_init(&gpio_sim_config_subsys.su_mutex); 1602 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1603 if (ret) { 1604 pr_err("Error %d while registering the configfs subsystem %s\n", 1605 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1606 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1607 platform_driver_unregister(&gpio_sim_driver); 1608 return ret; 1609 } 1610 1611 return 0; 1612 } 1613 module_init(gpio_sim_init); 1614 1615 static void __exit gpio_sim_exit(void) 1616 { 1617 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1618 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1619 platform_driver_unregister(&gpio_sim_driver); 1620 } 1621 module_exit(gpio_sim_exit); 1622 1623 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); 1624 MODULE_DESCRIPTION("GPIO Simulator Module"); 1625 MODULE_LICENSE("GPL"); 1626