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/bitmap.h> 11#include <linux/cleanup.h> 12#include <linux/completion.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/kernel.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 44static DEFINE_IDA(gpio_sim_ida); 45 46struct 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 58struct gpio_sim_attribute { 59 struct device_attribute dev_attr; 60 unsigned int offset; 61}; 62 63static struct gpio_sim_attribute * 64to_gpio_sim_attr(struct device_attribute *dev_attr) 65{ 66 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 67} 68 69static 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 102set_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 108set_pull: 109 __assign_bit(offset, chip->pull_map, value); 110 return 0; 111} 112 113static 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 122static 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 130static 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 141static 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 151static 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 164static 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 174static 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 185static 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 202static 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 209static 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 219static 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 230static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc) 231{ 232 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 233 const char *label; 234 int i; 235 236 guard(mutex)(&chip->lock); 237 238 for_each_hwgpio(gc, i, label) 239 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n", 240 gc->base + i, 241 label ?: "<unused>", 242 test_bit(i, chip->direction_map) ? "input" : 243 test_bit(i, chip->value_map) ? "output-high" : 244 "output-low", 245 test_bit(i, chip->pull_map) ? "pull-up" : 246 "pull-down"); 247} 248 249static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 250 struct device_attribute *attr, char *buf) 251{ 252 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 253 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 254 int val; 255 256 scoped_guard(mutex, &chip->lock) 257 val = !!test_bit(line_attr->offset, chip->value_map); 258 259 return sysfs_emit(buf, "%d\n", val); 260} 261 262static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 263 struct device_attribute *attr, 264 const char *buf, size_t count) 265{ 266 /* 267 * Not assigning this function will result in write() returning -EIO 268 * which is confusing. Return -EPERM explicitly. 269 */ 270 return -EPERM; 271} 272 273static const char *const gpio_sim_sysfs_pull_strings[] = { 274 [0] = "pull-down", 275 [1] = "pull-up", 276}; 277 278static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 279 struct device_attribute *attr, 280 char *buf) 281{ 282 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 283 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 284 int pull; 285 286 scoped_guard(mutex, &chip->lock) 287 pull = !!test_bit(line_attr->offset, chip->pull_map); 288 289 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 290} 291 292static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 293 struct device_attribute *attr, 294 const char *buf, size_t len) 295{ 296 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 297 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 298 int ret, pull; 299 300 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 301 if (pull < 0) 302 return pull; 303 304 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 305 if (ret) 306 return ret; 307 308 return len; 309} 310 311static void gpio_sim_mutex_destroy(void *data) 312{ 313 struct mutex *lock = data; 314 315 mutex_destroy(lock); 316} 317 318static void gpio_sim_put_device(void *data) 319{ 320 struct device *dev = data; 321 322 put_device(dev); 323} 324 325static void gpio_sim_dispose_mappings(void *data) 326{ 327 struct gpio_sim_chip *chip = data; 328 unsigned int i; 329 330 for (i = 0; i < chip->gc.ngpio; i++) 331 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 332} 333 334static void gpio_sim_sysfs_remove(void *data) 335{ 336 struct gpio_sim_chip *chip = data; 337 338 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups); 339} 340 341static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 342{ 343 struct device_attribute *val_dev_attr, *pull_dev_attr; 344 struct gpio_sim_attribute *val_attr, *pull_attr; 345 unsigned int num_lines = chip->gc.ngpio; 346 struct device *dev = chip->gc.parent; 347 struct attribute_group *attr_group; 348 struct attribute **attrs; 349 int i, ret; 350 351 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 352 num_lines + 1, GFP_KERNEL); 353 if (!chip->attr_groups) 354 return -ENOMEM; 355 356 for (i = 0; i < num_lines; i++) { 357 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 358 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 359 GFP_KERNEL); 360 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 361 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 362 if (!attr_group || !attrs || !val_attr || !pull_attr) 363 return -ENOMEM; 364 365 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 366 "sim_gpio%u", i); 367 if (!attr_group->name) 368 return -ENOMEM; 369 370 val_attr->offset = pull_attr->offset = i; 371 372 val_dev_attr = &val_attr->dev_attr; 373 pull_dev_attr = &pull_attr->dev_attr; 374 375 sysfs_attr_init(&val_dev_attr->attr); 376 sysfs_attr_init(&pull_dev_attr->attr); 377 378 val_dev_attr->attr.name = "value"; 379 pull_dev_attr->attr.name = "pull"; 380 381 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 382 383 val_dev_attr->show = gpio_sim_sysfs_val_show; 384 val_dev_attr->store = gpio_sim_sysfs_val_store; 385 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 386 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 387 388 attrs[0] = &val_dev_attr->attr; 389 attrs[1] = &pull_dev_attr->attr; 390 391 attr_group->attrs = attrs; 392 chip->attr_groups[i] = attr_group; 393 } 394 395 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups); 396 if (ret) 397 return ret; 398 399 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 400} 401 402static int gpio_sim_dev_match_fwnode(struct device *dev, void *data) 403{ 404 return device_match_fwnode(dev, data); 405} 406 407static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 408{ 409 struct gpio_sim_chip *chip; 410 struct gpio_chip *gc; 411 const char *label; 412 u32 num_lines; 413 int ret; 414 415 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 416 if (ret) 417 return ret; 418 419 if (num_lines > GPIO_SIM_NGPIO_MAX) 420 return -ERANGE; 421 422 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 423 if (ret) { 424 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP", 425 dev_name(dev), swnode); 426 if (!label) 427 return -ENOMEM; 428 } 429 430 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 431 if (!chip) 432 return -ENOMEM; 433 434 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 435 if (!chip->request_map) 436 return -ENOMEM; 437 438 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 439 if (!chip->direction_map) 440 return -ENOMEM; 441 442 /* Default to input mode. */ 443 bitmap_fill(chip->direction_map, num_lines); 444 445 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 446 if (!chip->value_map) 447 return -ENOMEM; 448 449 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 450 if (!chip->pull_map) 451 return -ENOMEM; 452 453 chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines); 454 if (IS_ERR(chip->irq_sim)) 455 return PTR_ERR(chip->irq_sim); 456 457 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 458 if (ret) 459 return ret; 460 461 mutex_init(&chip->lock); 462 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy, 463 &chip->lock); 464 if (ret) 465 return ret; 466 467 gc = &chip->gc; 468 gc->base = -1; 469 gc->ngpio = num_lines; 470 gc->label = label; 471 gc->owner = THIS_MODULE; 472 gc->parent = dev; 473 gc->fwnode = swnode; 474 gc->get = gpio_sim_get; 475 gc->set = gpio_sim_set; 476 gc->get_multiple = gpio_sim_get_multiple; 477 gc->set_multiple = gpio_sim_set_multiple; 478 gc->direction_output = gpio_sim_direction_output; 479 gc->direction_input = gpio_sim_direction_input; 480 gc->get_direction = gpio_sim_get_direction; 481 gc->set_config = gpio_sim_set_config; 482 gc->to_irq = gpio_sim_to_irq; 483 gc->request = gpio_sim_request; 484 gc->free = gpio_sim_free; 485 gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show); 486 gc->can_sleep = true; 487 488 ret = devm_gpiochip_add_data(dev, gc, chip); 489 if (ret) 490 return ret; 491 492 chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode); 493 if (!chip->dev) 494 return -ENODEV; 495 496 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev); 497 if (ret) 498 return ret; 499 500 /* Used by sysfs callbacks. */ 501 dev_set_drvdata(chip->dev, chip); 502 503 return gpio_sim_setup_sysfs(chip); 504} 505 506static int gpio_sim_probe(struct platform_device *pdev) 507{ 508 struct device *dev = &pdev->dev; 509 struct fwnode_handle *swnode; 510 int ret; 511 512 device_for_each_child_node(dev, swnode) { 513 ret = gpio_sim_add_bank(swnode, dev); 514 if (ret) { 515 fwnode_handle_put(swnode); 516 return ret; 517 } 518 } 519 520 return 0; 521} 522 523static const struct of_device_id gpio_sim_of_match[] = { 524 { .compatible = "gpio-simulator" }, 525 { } 526}; 527MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 528 529static struct platform_driver gpio_sim_driver = { 530 .driver = { 531 .name = "gpio-sim", 532 .of_match_table = gpio_sim_of_match, 533 }, 534 .probe = gpio_sim_probe, 535}; 536 537struct gpio_sim_device { 538 struct config_group group; 539 540 /* 541 * If pdev is NULL, the device is 'pending' (waiting for configuration). 542 * Once the pointer is assigned, the device has been created and the 543 * item is 'live'. 544 */ 545 struct platform_device *pdev; 546 int id; 547 548 /* 549 * Each configfs filesystem operation is protected with the subsystem 550 * mutex. Each separate attribute is protected with the buffer mutex. 551 * This structure however can be modified by callbacks of different 552 * attributes so we need another lock. 553 * 554 * We use this lock for protecting all data structures owned by this 555 * object too. 556 */ 557 struct mutex lock; 558 559 /* 560 * This is used to synchronously wait for the driver's probe to complete 561 * and notify the user-space about any errors. 562 */ 563 struct notifier_block bus_notifier; 564 struct completion probe_completion; 565 bool driver_bound; 566 567 struct gpiod_hog *hogs; 568 569 struct list_head bank_list; 570}; 571 572/* This is called with dev->lock already taken. */ 573static int gpio_sim_bus_notifier_call(struct notifier_block *nb, 574 unsigned long action, void *data) 575{ 576 struct gpio_sim_device *simdev = container_of(nb, 577 struct gpio_sim_device, 578 bus_notifier); 579 struct device *dev = data; 580 char devname[32]; 581 582 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id); 583 584 if (strcmp(dev_name(dev), devname) == 0) { 585 if (action == BUS_NOTIFY_BOUND_DRIVER) 586 simdev->driver_bound = true; 587 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND) 588 simdev->driver_bound = false; 589 else 590 return NOTIFY_DONE; 591 592 complete(&simdev->probe_completion); 593 return NOTIFY_OK; 594 } 595 596 return NOTIFY_DONE; 597} 598 599static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 600{ 601 struct config_group *group = to_config_group(item); 602 603 return container_of(group, struct gpio_sim_device, group); 604} 605 606struct gpio_sim_bank { 607 struct config_group group; 608 609 /* 610 * We could have used the ci_parent field of the config_item but 611 * configfs is stupid and calls the item's release callback after 612 * already having cleared the parent pointer even though the parent 613 * is guaranteed to survive the child... 614 * 615 * So we need to store the pointer to the parent struct here. We can 616 * dereference it anywhere we need with no checks and no locking as 617 * it's guaranteed to survive the children and protected by configfs 618 * locks. 619 * 620 * Same for other structures. 621 */ 622 struct gpio_sim_device *parent; 623 struct list_head siblings; 624 625 char *label; 626 unsigned int num_lines; 627 628 struct list_head line_list; 629 630 struct fwnode_handle *swnode; 631}; 632 633static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 634{ 635 struct config_group *group = to_config_group(item); 636 637 return container_of(group, struct gpio_sim_bank, group); 638} 639 640static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 641{ 642 return bank->label && *bank->label; 643} 644 645static struct gpio_sim_device * 646gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 647{ 648 return bank->parent; 649} 650 651struct gpio_sim_hog; 652 653struct gpio_sim_line { 654 struct config_group group; 655 656 struct gpio_sim_bank *parent; 657 struct list_head siblings; 658 659 unsigned int offset; 660 char *name; 661 662 /* There can only be one hog per line. */ 663 struct gpio_sim_hog *hog; 664}; 665 666static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 667{ 668 struct config_group *group = to_config_group(item); 669 670 return container_of(group, struct gpio_sim_line, group); 671} 672 673static struct gpio_sim_device * 674gpio_sim_line_get_device(struct gpio_sim_line *line) 675{ 676 struct gpio_sim_bank *bank = line->parent; 677 678 return gpio_sim_bank_get_device(bank); 679} 680 681struct gpio_sim_hog { 682 struct config_item item; 683 struct gpio_sim_line *parent; 684 685 char *name; 686 int dir; 687}; 688 689static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 690{ 691 return container_of(item, struct gpio_sim_hog, item); 692} 693 694static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 695{ 696 struct gpio_sim_line *line = hog->parent; 697 698 return gpio_sim_line_get_device(line); 699} 700 701static bool gpio_sim_device_is_live(struct gpio_sim_device *dev) 702{ 703 lockdep_assert_held(&dev->lock); 704 705 return !!dev->pdev; 706} 707 708static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 709{ 710 char *trimmed; 711 712 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL); 713 if (!trimmed) 714 return NULL; 715 716 return strim(trimmed); 717} 718 719static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 720 char *page) 721{ 722 struct gpio_sim_device *dev = to_gpio_sim_device(item); 723 struct platform_device *pdev; 724 725 guard(mutex)(&dev->lock); 726 727 pdev = dev->pdev; 728 if (pdev) 729 return sprintf(page, "%s\n", dev_name(&pdev->dev)); 730 731 return sprintf(page, "gpio-sim.%d\n", dev->id); 732} 733 734CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 735 736static ssize_t 737gpio_sim_device_config_live_show(struct config_item *item, char *page) 738{ 739 struct gpio_sim_device *dev = to_gpio_sim_device(item); 740 bool live; 741 742 scoped_guard(mutex, &dev->lock) 743 live = gpio_sim_device_is_live(dev); 744 745 return sprintf(page, "%c\n", live ? '1' : '0'); 746} 747 748static unsigned int gpio_sim_get_line_names_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->name || (line->offset >= bank->num_lines)) 755 continue; 756 757 size = max(size, line->offset + 1); 758 } 759 760 return size; 761} 762 763static void 764gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names) 765{ 766 struct gpio_sim_line *line; 767 768 list_for_each_entry(line, &bank->line_list, siblings) { 769 if (!line->name || (line->offset >= bank->num_lines)) 770 continue; 771 772 line_names[line->offset] = line->name; 773 } 774} 775 776static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 777{ 778 struct gpiod_hog *hog; 779 780 if (!dev->hogs) 781 return; 782 783 gpiod_remove_hogs(dev->hogs); 784 785 for (hog = dev->hogs; hog->chip_label; hog++) { 786 kfree(hog->chip_label); 787 kfree(hog->line_name); 788 } 789 790 kfree(dev->hogs); 791 dev->hogs = NULL; 792} 793 794static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 795{ 796 unsigned int num_hogs = 0, idx = 0; 797 struct gpio_sim_bank *bank; 798 struct gpio_sim_line *line; 799 struct gpiod_hog *hog; 800 801 list_for_each_entry(bank, &dev->bank_list, siblings) { 802 list_for_each_entry(line, &bank->line_list, siblings) { 803 if (line->offset >= bank->num_lines) 804 continue; 805 806 if (line->hog) 807 num_hogs++; 808 } 809 } 810 811 if (!num_hogs) 812 return 0; 813 814 /* Allocate one more for the sentinel. */ 815 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 816 if (!dev->hogs) 817 return -ENOMEM; 818 819 list_for_each_entry(bank, &dev->bank_list, siblings) { 820 list_for_each_entry(line, &bank->line_list, siblings) { 821 if (line->offset >= bank->num_lines) 822 continue; 823 824 if (!line->hog) 825 continue; 826 827 hog = &dev->hogs[idx++]; 828 829 /* 830 * We need to make this string manually because at this 831 * point the device doesn't exist yet and so dev_name() 832 * is not available. 833 */ 834 if (gpio_sim_bank_has_label(bank)) 835 hog->chip_label = kstrdup(bank->label, 836 GFP_KERNEL); 837 else 838 hog->chip_label = kasprintf(GFP_KERNEL, 839 "gpio-sim.%u:%pfwP", 840 dev->id, 841 bank->swnode); 842 if (!hog->chip_label) { 843 gpio_sim_remove_hogs(dev); 844 return -ENOMEM; 845 } 846 847 /* 848 * We need to duplicate this because the hog config 849 * item can be removed at any time (and we can't block 850 * it) and gpiolib doesn't make a deep copy of the hog 851 * data. 852 */ 853 if (line->hog->name) { 854 hog->line_name = kstrdup(line->hog->name, 855 GFP_KERNEL); 856 if (!hog->line_name) { 857 gpio_sim_remove_hogs(dev); 858 return -ENOMEM; 859 } 860 } 861 862 hog->chip_hwnum = line->offset; 863 hog->dflags = line->hog->dir; 864 } 865 } 866 867 gpiod_add_hogs(dev->hogs); 868 869 return 0; 870} 871 872static struct fwnode_handle * 873gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 874 struct fwnode_handle *parent) 875{ 876 struct property_entry properties[GPIO_SIM_PROP_MAX]; 877 unsigned int prop_idx = 0, line_names_size; 878 char **line_names __free(kfree) = NULL; 879 880 memset(properties, 0, sizeof(properties)); 881 882 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 883 884 if (gpio_sim_bank_has_label(bank)) 885 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 886 bank->label); 887 888 line_names_size = gpio_sim_get_line_names_size(bank); 889 if (line_names_size) { 890 line_names = kcalloc(line_names_size, sizeof(*line_names), 891 GFP_KERNEL); 892 if (!line_names) 893 return ERR_PTR(-ENOMEM); 894 895 gpio_sim_set_line_names(bank, line_names); 896 897 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 898 "gpio-line-names", 899 line_names, line_names_size); 900 } 901 902 return fwnode_create_software_node(properties, parent); 903} 904 905static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 906{ 907 struct fwnode_handle *child; 908 909 fwnode_for_each_child_node(swnode, child) 910 fwnode_remove_software_node(child); 911 912 fwnode_remove_software_node(swnode); 913} 914 915static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 916{ 917 struct gpio_sim_bank *this, *pos; 918 919 list_for_each_entry(this, &dev->bank_list, siblings) { 920 list_for_each_entry(pos, &dev->bank_list, siblings) { 921 if (this == pos || (!this->label || !pos->label)) 922 continue; 923 924 if (strcmp(this->label, pos->label) == 0) 925 return true; 926 } 927 } 928 929 return false; 930} 931 932static int gpio_sim_device_activate(struct gpio_sim_device *dev) 933{ 934 struct platform_device_info pdevinfo; 935 struct fwnode_handle *swnode; 936 struct platform_device *pdev; 937 struct gpio_sim_bank *bank; 938 int ret; 939 940 lockdep_assert_held(&dev->lock); 941 942 if (list_empty(&dev->bank_list)) 943 return -ENODATA; 944 945 /* 946 * Non-unique GPIO device labels are a corner-case we don't support 947 * as it would interfere with machine hogging mechanism and has little 948 * use in real life. 949 */ 950 if (gpio_sim_bank_labels_non_unique(dev)) 951 return -EINVAL; 952 953 memset(&pdevinfo, 0, sizeof(pdevinfo)); 954 955 swnode = fwnode_create_software_node(NULL, NULL); 956 if (IS_ERR(swnode)) 957 return PTR_ERR(swnode); 958 959 list_for_each_entry(bank, &dev->bank_list, siblings) { 960 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 961 if (IS_ERR(bank->swnode)) { 962 ret = PTR_ERR(bank->swnode); 963 gpio_sim_remove_swnode_recursive(swnode); 964 return ret; 965 } 966 } 967 968 ret = gpio_sim_add_hogs(dev); 969 if (ret) { 970 gpio_sim_remove_swnode_recursive(swnode); 971 return ret; 972 } 973 974 pdevinfo.name = "gpio-sim"; 975 pdevinfo.fwnode = swnode; 976 pdevinfo.id = dev->id; 977 978 reinit_completion(&dev->probe_completion); 979 dev->driver_bound = false; 980 bus_register_notifier(&platform_bus_type, &dev->bus_notifier); 981 982 pdev = platform_device_register_full(&pdevinfo); 983 if (IS_ERR(pdev)) { 984 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 985 gpio_sim_remove_hogs(dev); 986 gpio_sim_remove_swnode_recursive(swnode); 987 return PTR_ERR(pdev); 988 } 989 990 wait_for_completion(&dev->probe_completion); 991 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 992 993 if (!dev->driver_bound) { 994 /* Probe failed, check kernel log. */ 995 platform_device_unregister(pdev); 996 gpio_sim_remove_hogs(dev); 997 gpio_sim_remove_swnode_recursive(swnode); 998 return -ENXIO; 999 } 1000 1001 dev->pdev = pdev; 1002 1003 return 0; 1004} 1005 1006static void gpio_sim_device_deactivate(struct gpio_sim_device *dev) 1007{ 1008 struct fwnode_handle *swnode; 1009 1010 lockdep_assert_held(&dev->lock); 1011 1012 swnode = dev_fwnode(&dev->pdev->dev); 1013 platform_device_unregister(dev->pdev); 1014 gpio_sim_remove_hogs(dev); 1015 gpio_sim_remove_swnode_recursive(swnode); 1016 dev->pdev = NULL; 1017} 1018 1019static ssize_t 1020gpio_sim_device_config_live_store(struct config_item *item, 1021 const char *page, size_t count) 1022{ 1023 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1024 bool live; 1025 int ret; 1026 1027 ret = kstrtobool(page, &live); 1028 if (ret) 1029 return ret; 1030 1031 guard(mutex)(&dev->lock); 1032 1033 if (live == gpio_sim_device_is_live(dev)) 1034 ret = -EPERM; 1035 else if (live) 1036 ret = gpio_sim_device_activate(dev); 1037 else 1038 gpio_sim_device_deactivate(dev); 1039 1040 return ret ?: count; 1041} 1042 1043CONFIGFS_ATTR(gpio_sim_device_config_, live); 1044 1045static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1046 &gpio_sim_device_config_attr_dev_name, 1047 &gpio_sim_device_config_attr_live, 1048 NULL 1049}; 1050 1051struct gpio_sim_chip_name_ctx { 1052 struct fwnode_handle *swnode; 1053 char *page; 1054}; 1055 1056static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1057{ 1058 struct gpio_sim_chip_name_ctx *ctx = data; 1059 1060 /* This would be the sysfs device exported in /sys/class/gpio. */ 1061 if (dev->class) 1062 return 0; 1063 1064 if (device_match_fwnode(dev, ctx->swnode)) 1065 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1066 1067 return 0; 1068} 1069 1070static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1071 char *page) 1072{ 1073 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1074 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1075 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1076 1077 guard(mutex)(&dev->lock); 1078 1079 if (gpio_sim_device_is_live(dev)) 1080 return device_for_each_child(&dev->pdev->dev, &ctx, 1081 gpio_sim_emit_chip_name); 1082 1083 return sprintf(page, "none\n"); 1084} 1085 1086CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1087 1088static ssize_t 1089gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1090{ 1091 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1092 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1093 1094 guard(mutex)(&dev->lock); 1095 1096 return sprintf(page, "%s\n", bank->label ?: ""); 1097} 1098 1099static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1100 const char *page, size_t count) 1101{ 1102 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1103 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1104 char *trimmed; 1105 1106 guard(mutex)(&dev->lock); 1107 1108 if (gpio_sim_device_is_live(dev)) 1109 return -EBUSY; 1110 1111 trimmed = gpio_sim_strdup_trimmed(page, count); 1112 if (!trimmed) 1113 return -ENOMEM; 1114 1115 kfree(bank->label); 1116 bank->label = trimmed; 1117 1118 return count; 1119} 1120 1121CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1122 1123static ssize_t 1124gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1125{ 1126 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1127 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1128 1129 guard(mutex)(&dev->lock); 1130 1131 return sprintf(page, "%u\n", bank->num_lines); 1132} 1133 1134static ssize_t 1135gpio_sim_bank_config_num_lines_store(struct config_item *item, 1136 const char *page, size_t count) 1137{ 1138 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1139 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1140 unsigned int num_lines; 1141 int ret; 1142 1143 ret = kstrtouint(page, 0, &num_lines); 1144 if (ret) 1145 return ret; 1146 1147 if (num_lines == 0) 1148 return -EINVAL; 1149 1150 guard(mutex)(&dev->lock); 1151 1152 if (gpio_sim_device_is_live(dev)) 1153 return -EBUSY; 1154 1155 bank->num_lines = num_lines; 1156 1157 return count; 1158} 1159 1160CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1161 1162static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1163 &gpio_sim_bank_config_attr_chip_name, 1164 &gpio_sim_bank_config_attr_label, 1165 &gpio_sim_bank_config_attr_num_lines, 1166 NULL 1167}; 1168 1169static ssize_t 1170gpio_sim_line_config_name_show(struct config_item *item, char *page) 1171{ 1172 struct gpio_sim_line *line = to_gpio_sim_line(item); 1173 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1174 1175 guard(mutex)(&dev->lock); 1176 1177 return sprintf(page, "%s\n", line->name ?: ""); 1178} 1179 1180static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1181 const char *page, size_t count) 1182{ 1183 struct gpio_sim_line *line = to_gpio_sim_line(item); 1184 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1185 char *trimmed; 1186 1187 guard(mutex)(&dev->lock); 1188 1189 if (gpio_sim_device_is_live(dev)) 1190 return -EBUSY; 1191 1192 trimmed = gpio_sim_strdup_trimmed(page, count); 1193 if (!trimmed) 1194 return -ENOMEM; 1195 1196 kfree(line->name); 1197 line->name = trimmed; 1198 1199 return count; 1200} 1201 1202CONFIGFS_ATTR(gpio_sim_line_config_, name); 1203 1204static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1205 &gpio_sim_line_config_attr_name, 1206 NULL 1207}; 1208 1209static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1210 char *page) 1211{ 1212 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1213 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1214 1215 guard(mutex)(&dev->lock); 1216 1217 return sprintf(page, "%s\n", hog->name ?: ""); 1218} 1219 1220static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1221 const char *page, size_t count) 1222{ 1223 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1224 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1225 char *trimmed; 1226 1227 guard(mutex)(&dev->lock); 1228 1229 if (gpio_sim_device_is_live(dev)) 1230 return -EBUSY; 1231 1232 trimmed = gpio_sim_strdup_trimmed(page, count); 1233 if (!trimmed) 1234 return -ENOMEM; 1235 1236 kfree(hog->name); 1237 hog->name = trimmed; 1238 1239 return count; 1240} 1241 1242CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1243 1244static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1245 char *page) 1246{ 1247 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1248 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1249 char *repr; 1250 int dir; 1251 1252 scoped_guard(mutex, &dev->lock) 1253 dir = hog->dir; 1254 1255 switch (dir) { 1256 case GPIOD_IN: 1257 repr = "input"; 1258 break; 1259 case GPIOD_OUT_HIGH: 1260 repr = "output-high"; 1261 break; 1262 case GPIOD_OUT_LOW: 1263 repr = "output-low"; 1264 break; 1265 default: 1266 /* This would be a programmer bug. */ 1267 WARN(1, "Unexpected hog direction value: %d", dir); 1268 return -EINVAL; 1269 } 1270 1271 return sprintf(page, "%s\n", repr); 1272} 1273 1274static ssize_t 1275gpio_sim_hog_config_direction_store(struct config_item *item, 1276 const char *page, size_t count) 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 int dir; 1281 1282 guard(mutex)(&dev->lock); 1283 1284 if (gpio_sim_device_is_live(dev)) 1285 return -EBUSY; 1286 1287 if (sysfs_streq(page, "input")) 1288 dir = GPIOD_IN; 1289 else if (sysfs_streq(page, "output-high")) 1290 dir = GPIOD_OUT_HIGH; 1291 else if (sysfs_streq(page, "output-low")) 1292 dir = GPIOD_OUT_LOW; 1293 else 1294 return -EINVAL; 1295 1296 hog->dir = dir; 1297 1298 return count; 1299} 1300 1301CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1302 1303static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1304 &gpio_sim_hog_config_attr_name, 1305 &gpio_sim_hog_config_attr_direction, 1306 NULL 1307}; 1308 1309static void gpio_sim_hog_config_item_release(struct config_item *item) 1310{ 1311 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1312 struct gpio_sim_line *line = hog->parent; 1313 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1314 1315 scoped_guard(mutex, &dev->lock) 1316 line->hog = NULL; 1317 1318 kfree(hog->name); 1319 kfree(hog); 1320} 1321 1322static struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1323 .release = gpio_sim_hog_config_item_release, 1324}; 1325 1326static const struct config_item_type gpio_sim_hog_config_type = { 1327 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1328 .ct_attrs = gpio_sim_hog_config_attrs, 1329 .ct_owner = THIS_MODULE, 1330}; 1331 1332static struct config_item * 1333gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1334{ 1335 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1336 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1337 struct gpio_sim_hog *hog; 1338 1339 if (strcmp(name, "hog") != 0) 1340 return ERR_PTR(-EINVAL); 1341 1342 guard(mutex)(&dev->lock); 1343 1344 hog = kzalloc(sizeof(*hog), GFP_KERNEL); 1345 if (!hog) 1346 return ERR_PTR(-ENOMEM); 1347 1348 config_item_init_type_name(&hog->item, name, 1349 &gpio_sim_hog_config_type); 1350 1351 hog->dir = GPIOD_IN; 1352 hog->name = NULL; 1353 hog->parent = line; 1354 line->hog = hog; 1355 1356 return &hog->item; 1357} 1358 1359static void gpio_sim_line_config_group_release(struct config_item *item) 1360{ 1361 struct gpio_sim_line *line = to_gpio_sim_line(item); 1362 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1363 1364 scoped_guard(mutex, &dev->lock) 1365 list_del(&line->siblings); 1366 1367 kfree(line->name); 1368 kfree(line); 1369} 1370 1371static struct configfs_item_operations gpio_sim_line_config_item_ops = { 1372 .release = gpio_sim_line_config_group_release, 1373}; 1374 1375static struct configfs_group_operations gpio_sim_line_config_group_ops = { 1376 .make_item = gpio_sim_line_config_make_hog_item, 1377}; 1378 1379static const struct config_item_type gpio_sim_line_config_type = { 1380 .ct_item_ops = &gpio_sim_line_config_item_ops, 1381 .ct_group_ops = &gpio_sim_line_config_group_ops, 1382 .ct_attrs = gpio_sim_line_config_attrs, 1383 .ct_owner = THIS_MODULE, 1384}; 1385 1386static struct config_group * 1387gpio_sim_bank_config_make_line_group(struct config_group *group, 1388 const char *name) 1389{ 1390 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1391 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1392 struct gpio_sim_line *line; 1393 unsigned int offset; 1394 int ret, nchar; 1395 1396 ret = sscanf(name, "line%u%n", &offset, &nchar); 1397 if (ret != 1 || nchar != strlen(name)) 1398 return ERR_PTR(-EINVAL); 1399 1400 guard(mutex)(&dev->lock); 1401 1402 if (gpio_sim_device_is_live(dev)) 1403 return ERR_PTR(-EBUSY); 1404 1405 line = kzalloc(sizeof(*line), GFP_KERNEL); 1406 if (!line) 1407 return ERR_PTR(-ENOMEM); 1408 1409 config_group_init_type_name(&line->group, name, 1410 &gpio_sim_line_config_type); 1411 1412 line->parent = bank; 1413 line->offset = offset; 1414 list_add_tail(&line->siblings, &bank->line_list); 1415 1416 return &line->group; 1417} 1418 1419static void gpio_sim_bank_config_group_release(struct config_item *item) 1420{ 1421 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1422 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1423 1424 scoped_guard(mutex, &dev->lock) 1425 list_del(&bank->siblings); 1426 1427 kfree(bank->label); 1428 kfree(bank); 1429} 1430 1431static struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1432 .release = gpio_sim_bank_config_group_release, 1433}; 1434 1435static struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1436 .make_group = gpio_sim_bank_config_make_line_group, 1437}; 1438 1439static const struct config_item_type gpio_sim_bank_config_group_type = { 1440 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1441 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1442 .ct_attrs = gpio_sim_bank_config_attrs, 1443 .ct_owner = THIS_MODULE, 1444}; 1445 1446static struct config_group * 1447gpio_sim_device_config_make_bank_group(struct config_group *group, 1448 const char *name) 1449{ 1450 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1451 struct gpio_sim_bank *bank; 1452 1453 guard(mutex)(&dev->lock); 1454 1455 if (gpio_sim_device_is_live(dev)) 1456 return ERR_PTR(-EBUSY); 1457 1458 bank = kzalloc(sizeof(*bank), GFP_KERNEL); 1459 if (!bank) 1460 return ERR_PTR(-ENOMEM); 1461 1462 config_group_init_type_name(&bank->group, name, 1463 &gpio_sim_bank_config_group_type); 1464 bank->num_lines = 1; 1465 bank->parent = dev; 1466 INIT_LIST_HEAD(&bank->line_list); 1467 list_add_tail(&bank->siblings, &dev->bank_list); 1468 1469 return &bank->group; 1470} 1471 1472static void gpio_sim_device_config_group_release(struct config_item *item) 1473{ 1474 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1475 1476 scoped_guard(mutex, &dev->lock) { 1477 if (gpio_sim_device_is_live(dev)) 1478 gpio_sim_device_deactivate(dev); 1479 } 1480 1481 mutex_destroy(&dev->lock); 1482 ida_free(&gpio_sim_ida, dev->id); 1483 kfree(dev); 1484} 1485 1486static struct configfs_item_operations gpio_sim_device_config_item_ops = { 1487 .release = gpio_sim_device_config_group_release, 1488}; 1489 1490static struct configfs_group_operations gpio_sim_device_config_group_ops = { 1491 .make_group = gpio_sim_device_config_make_bank_group, 1492}; 1493 1494static const struct config_item_type gpio_sim_device_config_group_type = { 1495 .ct_item_ops = &gpio_sim_device_config_item_ops, 1496 .ct_group_ops = &gpio_sim_device_config_group_ops, 1497 .ct_attrs = gpio_sim_device_config_attrs, 1498 .ct_owner = THIS_MODULE, 1499}; 1500 1501static struct config_group * 1502gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1503{ 1504 int id; 1505 1506 struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev), 1507 GFP_KERNEL); 1508 if (!dev) 1509 return ERR_PTR(-ENOMEM); 1510 1511 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1512 if (id < 0) 1513 return ERR_PTR(id); 1514 1515 config_group_init_type_name(&dev->group, name, 1516 &gpio_sim_device_config_group_type); 1517 dev->id = id; 1518 mutex_init(&dev->lock); 1519 INIT_LIST_HEAD(&dev->bank_list); 1520 1521 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call; 1522 init_completion(&dev->probe_completion); 1523 1524 return &no_free_ptr(dev)->group; 1525} 1526 1527static struct configfs_group_operations gpio_sim_config_group_ops = { 1528 .make_group = gpio_sim_config_make_device_group, 1529}; 1530 1531static const struct config_item_type gpio_sim_config_type = { 1532 .ct_group_ops = &gpio_sim_config_group_ops, 1533 .ct_owner = THIS_MODULE, 1534}; 1535 1536static struct configfs_subsystem gpio_sim_config_subsys = { 1537 .su_group = { 1538 .cg_item = { 1539 .ci_namebuf = "gpio-sim", 1540 .ci_type = &gpio_sim_config_type, 1541 }, 1542 }, 1543}; 1544 1545static int __init gpio_sim_init(void) 1546{ 1547 int ret; 1548 1549 ret = platform_driver_register(&gpio_sim_driver); 1550 if (ret) { 1551 pr_err("Error %d while registering the platform driver\n", ret); 1552 return ret; 1553 } 1554 1555 config_group_init(&gpio_sim_config_subsys.su_group); 1556 mutex_init(&gpio_sim_config_subsys.su_mutex); 1557 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1558 if (ret) { 1559 pr_err("Error %d while registering the configfs subsystem %s\n", 1560 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1561 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1562 platform_driver_unregister(&gpio_sim_driver); 1563 return ret; 1564 } 1565 1566 return 0; 1567} 1568module_init(gpio_sim_init); 1569 1570static void __exit gpio_sim_exit(void) 1571{ 1572 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1573 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1574 platform_driver_unregister(&gpio_sim_driver); 1575} 1576module_exit(gpio_sim_exit); 1577 1578MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); 1579MODULE_DESCRIPTION("GPIO Simulator Module"); 1580MODULE_LICENSE("GPL"); 1581