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/completion.h> 12 #include <linux/configfs.h> 13 #include <linux/device.h> 14 #include <linux/gpio/driver.h> 15 #include <linux/gpio/machine.h> 16 #include <linux/idr.h> 17 #include <linux/interrupt.h> 18 #include <linux/irq.h> 19 #include <linux/irq_sim.h> 20 #include <linux/list.h> 21 #include <linux/mod_devicetable.h> 22 #include <linux/module.h> 23 #include <linux/mutex.h> 24 #include <linux/notifier.h> 25 #include <linux/platform_device.h> 26 #include <linux/property.h> 27 #include <linux/slab.h> 28 #include <linux/string.h> 29 #include <linux/string_helpers.h> 30 #include <linux/sysfs.h> 31 32 #include "gpiolib.h" 33 34 #define GPIO_SIM_NGPIO_MAX 1024 35 #define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */ 36 #define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */ 37 38 static DEFINE_IDA(gpio_sim_ida); 39 40 struct gpio_sim_chip { 41 struct gpio_chip gc; 42 unsigned long *direction_map; 43 unsigned long *value_map; 44 unsigned long *pull_map; 45 struct irq_domain *irq_sim; 46 struct mutex lock; 47 const struct attribute_group **attr_groups; 48 }; 49 50 struct gpio_sim_attribute { 51 struct device_attribute dev_attr; 52 unsigned int offset; 53 }; 54 55 static struct gpio_sim_attribute * 56 to_gpio_sim_attr(struct device_attribute *dev_attr) 57 { 58 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr); 59 } 60 61 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 62 unsigned int offset, int value) 63 { 64 int irq, irq_type, ret; 65 struct gpio_desc *desc; 66 struct gpio_chip *gc; 67 68 gc = &chip->gc; 69 desc = &gc->gpiodev->descs[offset]; 70 71 mutex_lock(&chip->lock); 72 73 if (test_bit(FLAG_REQUESTED, &desc->flags) && 74 !test_bit(FLAG_IS_OUT, &desc->flags)) { 75 if (value == !!test_bit(offset, chip->value_map)) 76 goto set_pull; 77 78 /* 79 * This is fine - it just means, nobody is listening 80 * for interrupts on this line, otherwise 81 * irq_create_mapping() would have been called from 82 * the to_irq() callback. 83 */ 84 irq = irq_find_mapping(chip->irq_sim, offset); 85 if (!irq) 86 goto set_value; 87 88 irq_type = irq_get_trigger_type(irq); 89 90 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) || 91 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) { 92 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 93 true); 94 if (ret) 95 goto set_pull; 96 } 97 } 98 99 set_value: 100 /* Change the value unless we're actively driving the line. */ 101 if (!test_bit(FLAG_REQUESTED, &desc->flags) || 102 !test_bit(FLAG_IS_OUT, &desc->flags)) 103 __assign_bit(offset, chip->value_map, value); 104 105 set_pull: 106 __assign_bit(offset, chip->pull_map, value); 107 mutex_unlock(&chip->lock); 108 return 0; 109 } 110 111 static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset) 112 { 113 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 114 int ret; 115 116 mutex_lock(&chip->lock); 117 ret = !!test_bit(offset, chip->value_map); 118 mutex_unlock(&chip->lock); 119 120 return ret; 121 } 122 123 static void 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 mutex_lock(&chip->lock); 128 __assign_bit(offset, chip->value_map, value); 129 mutex_unlock(&chip->lock); 130 } 131 132 static int gpio_sim_get_multiple(struct gpio_chip *gc, 133 unsigned long *mask, unsigned long *bits) 134 { 135 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 136 137 mutex_lock(&chip->lock); 138 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio); 139 mutex_unlock(&chip->lock); 140 141 return 0; 142 } 143 144 static void 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 mutex_lock(&chip->lock); 150 bitmap_replace(chip->value_map, chip->value_map, bits, mask, gc->ngpio); 151 mutex_unlock(&chip->lock); 152 } 153 154 static int gpio_sim_direction_output(struct gpio_chip *gc, 155 unsigned int offset, int value) 156 { 157 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 158 159 mutex_lock(&chip->lock); 160 __clear_bit(offset, chip->direction_map); 161 __assign_bit(offset, chip->value_map, value); 162 mutex_unlock(&chip->lock); 163 164 return 0; 165 } 166 167 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset) 168 { 169 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 170 171 mutex_lock(&chip->lock); 172 __set_bit(offset, chip->direction_map); 173 mutex_unlock(&chip->lock); 174 175 return 0; 176 } 177 178 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 179 { 180 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 181 int direction; 182 183 mutex_lock(&chip->lock); 184 direction = !!test_bit(offset, chip->direction_map); 185 mutex_unlock(&chip->lock); 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, 191 unsigned int offset, 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 void gpio_sim_free(struct gpio_chip *gc, unsigned int offset) 215 { 216 struct gpio_sim_chip *chip = gpiochip_get_data(gc); 217 218 mutex_lock(&chip->lock); 219 __assign_bit(offset, chip->value_map, !!test_bit(offset, chip->pull_map)); 220 mutex_unlock(&chip->lock); 221 } 222 223 static ssize_t gpio_sim_sysfs_val_show(struct device *dev, 224 struct device_attribute *attr, char *buf) 225 { 226 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 227 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 228 int val; 229 230 mutex_lock(&chip->lock); 231 val = !!test_bit(line_attr->offset, chip->value_map); 232 mutex_unlock(&chip->lock); 233 234 return sysfs_emit(buf, "%d\n", val); 235 } 236 237 static ssize_t gpio_sim_sysfs_val_store(struct device *dev, 238 struct device_attribute *attr, 239 const char *buf, size_t count) 240 { 241 /* 242 * Not assigning this function will result in write() returning -EIO 243 * which is confusing. Return -EPERM explicitly. 244 */ 245 return -EPERM; 246 } 247 248 static const char *const gpio_sim_sysfs_pull_strings[] = { 249 [0] = "pull-down", 250 [1] = "pull-up", 251 }; 252 253 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev, 254 struct device_attribute *attr, 255 char *buf) 256 { 257 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 258 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 259 int pull; 260 261 mutex_lock(&chip->lock); 262 pull = !!test_bit(line_attr->offset, chip->pull_map); 263 mutex_unlock(&chip->lock); 264 265 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]); 266 } 267 268 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev, 269 struct device_attribute *attr, 270 const char *buf, size_t len) 271 { 272 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr); 273 struct gpio_sim_chip *chip = dev_get_drvdata(dev); 274 int ret, pull; 275 276 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf); 277 if (pull < 0) 278 return pull; 279 280 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull); 281 if (ret) 282 return ret; 283 284 return len; 285 } 286 287 static void gpio_sim_mutex_destroy(void *data) 288 { 289 struct mutex *lock = data; 290 291 mutex_destroy(lock); 292 } 293 294 static void gpio_sim_dispose_mappings(void *data) 295 { 296 struct gpio_sim_chip *chip = data; 297 unsigned int i; 298 299 for (i = 0; i < chip->gc.ngpio; i++) 300 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i)); 301 } 302 303 static void gpio_sim_sysfs_remove(void *data) 304 { 305 struct gpio_sim_chip *chip = data; 306 307 sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups); 308 } 309 310 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 311 { 312 struct device_attribute *val_dev_attr, *pull_dev_attr; 313 struct gpio_sim_attribute *val_attr, *pull_attr; 314 unsigned int num_lines = chip->gc.ngpio; 315 struct device *dev = chip->gc.parent; 316 struct attribute_group *attr_group; 317 struct attribute **attrs; 318 int i, ret; 319 320 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups), 321 num_lines + 1, GFP_KERNEL); 322 if (!chip->attr_groups) 323 return -ENOMEM; 324 325 for (i = 0; i < num_lines; i++) { 326 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL); 327 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs), 328 GFP_KERNEL); 329 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL); 330 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL); 331 if (!attr_group || !attrs || !val_attr || !pull_attr) 332 return -ENOMEM; 333 334 attr_group->name = devm_kasprintf(dev, GFP_KERNEL, 335 "sim_gpio%u", i); 336 if (!attr_group->name) 337 return -ENOMEM; 338 339 val_attr->offset = pull_attr->offset = i; 340 341 val_dev_attr = &val_attr->dev_attr; 342 pull_dev_attr = &pull_attr->dev_attr; 343 344 sysfs_attr_init(&val_dev_attr->attr); 345 sysfs_attr_init(&pull_dev_attr->attr); 346 347 val_dev_attr->attr.name = "value"; 348 pull_dev_attr->attr.name = "pull"; 349 350 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644; 351 352 val_dev_attr->show = gpio_sim_sysfs_val_show; 353 val_dev_attr->store = gpio_sim_sysfs_val_store; 354 pull_dev_attr->show = gpio_sim_sysfs_pull_show; 355 pull_dev_attr->store = gpio_sim_sysfs_pull_store; 356 357 attrs[0] = &val_dev_attr->attr; 358 attrs[1] = &pull_dev_attr->attr; 359 360 attr_group->attrs = attrs; 361 chip->attr_groups[i] = attr_group; 362 } 363 364 ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj, 365 chip->attr_groups); 366 if (ret) 367 return ret; 368 369 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip); 370 } 371 372 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 373 { 374 struct gpio_sim_chip *chip; 375 struct gpio_chip *gc; 376 const char *label; 377 u32 num_lines; 378 int ret; 379 380 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines); 381 if (ret) 382 return ret; 383 384 if (num_lines > GPIO_SIM_NGPIO_MAX) 385 return -ERANGE; 386 387 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label); 388 if (ret) { 389 label = devm_kasprintf(dev, GFP_KERNEL, "%s-%pfwP", 390 dev_name(dev), swnode); 391 if (!label) 392 return -ENOMEM; 393 } 394 395 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 396 if (!chip) 397 return -ENOMEM; 398 399 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL); 400 if (!chip->direction_map) 401 return -ENOMEM; 402 403 /* Default to input mode. */ 404 bitmap_fill(chip->direction_map, num_lines); 405 406 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 407 if (!chip->value_map) 408 return -ENOMEM; 409 410 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL); 411 if (!chip->pull_map) 412 return -ENOMEM; 413 414 chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines); 415 if (IS_ERR(chip->irq_sim)) 416 return PTR_ERR(chip->irq_sim); 417 418 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip); 419 if (ret) 420 return ret; 421 422 mutex_init(&chip->lock); 423 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy, 424 &chip->lock); 425 if (ret) 426 return ret; 427 428 gc = &chip->gc; 429 gc->base = -1; 430 gc->ngpio = num_lines; 431 gc->label = label; 432 gc->owner = THIS_MODULE; 433 gc->parent = dev; 434 gc->fwnode = swnode; 435 gc->get = gpio_sim_get; 436 gc->set = gpio_sim_set; 437 gc->get_multiple = gpio_sim_get_multiple; 438 gc->set_multiple = gpio_sim_set_multiple; 439 gc->direction_output = gpio_sim_direction_output; 440 gc->direction_input = gpio_sim_direction_input; 441 gc->get_direction = gpio_sim_get_direction; 442 gc->set_config = gpio_sim_set_config; 443 gc->to_irq = gpio_sim_to_irq; 444 gc->free = gpio_sim_free; 445 gc->can_sleep = true; 446 447 ret = devm_gpiochip_add_data(dev, gc, chip); 448 if (ret) 449 return ret; 450 451 /* Used by sysfs and configfs callbacks. */ 452 dev_set_drvdata(&gc->gpiodev->dev, chip); 453 454 return gpio_sim_setup_sysfs(chip); 455 } 456 457 static int gpio_sim_probe(struct platform_device *pdev) 458 { 459 struct device *dev = &pdev->dev; 460 struct fwnode_handle *swnode; 461 int ret; 462 463 device_for_each_child_node(dev, swnode) { 464 ret = gpio_sim_add_bank(swnode, dev); 465 if (ret) { 466 fwnode_handle_put(swnode); 467 return ret; 468 } 469 } 470 471 return 0; 472 } 473 474 static const struct of_device_id gpio_sim_of_match[] = { 475 { .compatible = "gpio-simulator" }, 476 { } 477 }; 478 MODULE_DEVICE_TABLE(of, gpio_sim_of_match); 479 480 static struct platform_driver gpio_sim_driver = { 481 .driver = { 482 .name = "gpio-sim", 483 .of_match_table = gpio_sim_of_match, 484 }, 485 .probe = gpio_sim_probe, 486 }; 487 488 struct gpio_sim_device { 489 struct config_group group; 490 491 /* 492 * If pdev is NULL, the device is 'pending' (waiting for configuration). 493 * Once the pointer is assigned, the device has been created and the 494 * item is 'live'. 495 */ 496 struct platform_device *pdev; 497 int id; 498 499 /* 500 * Each configfs filesystem operation is protected with the subsystem 501 * mutex. Each separate attribute is protected with the buffer mutex. 502 * This structure however can be modified by callbacks of different 503 * attributes so we need another lock. 504 * 505 * We use this lock fo protecting all data structures owned by this 506 * object too. 507 */ 508 struct mutex lock; 509 510 /* 511 * This is used to synchronously wait for the driver's probe to complete 512 * and notify the user-space about any errors. 513 */ 514 struct notifier_block bus_notifier; 515 struct completion probe_completion; 516 bool driver_bound; 517 518 struct gpiod_hog *hogs; 519 520 struct list_head bank_list; 521 }; 522 523 /* This is called with dev->lock already taken. */ 524 static int gpio_sim_bus_notifier_call(struct notifier_block *nb, 525 unsigned long action, void *data) 526 { 527 struct gpio_sim_device *simdev = container_of(nb, 528 struct gpio_sim_device, 529 bus_notifier); 530 struct device *dev = data; 531 char devname[32]; 532 533 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id); 534 535 if (strcmp(dev_name(dev), devname) == 0) { 536 if (action == BUS_NOTIFY_BOUND_DRIVER) 537 simdev->driver_bound = true; 538 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND) 539 simdev->driver_bound = false; 540 else 541 return NOTIFY_DONE; 542 543 complete(&simdev->probe_completion); 544 return NOTIFY_OK; 545 } 546 547 return NOTIFY_DONE; 548 } 549 550 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item) 551 { 552 struct config_group *group = to_config_group(item); 553 554 return container_of(group, struct gpio_sim_device, group); 555 } 556 557 struct gpio_sim_bank { 558 struct config_group group; 559 560 /* 561 * We could have used the ci_parent field of the config_item but 562 * configfs is stupid and calls the item's release callback after 563 * already having cleared the parent pointer even though the parent 564 * is guaranteed to survive the child... 565 * 566 * So we need to store the pointer to the parent struct here. We can 567 * dereference it anywhere we need with no checks and no locking as 568 * it's guaranteed to survive the children and protected by configfs 569 * locks. 570 * 571 * Same for other structures. 572 */ 573 struct gpio_sim_device *parent; 574 struct list_head siblings; 575 576 char *label; 577 unsigned int num_lines; 578 579 struct list_head line_list; 580 581 struct fwnode_handle *swnode; 582 }; 583 584 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item) 585 { 586 struct config_group *group = to_config_group(item); 587 588 return container_of(group, struct gpio_sim_bank, group); 589 } 590 591 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank) 592 { 593 return bank->label && *bank->label; 594 } 595 596 static struct gpio_sim_device * 597 gpio_sim_bank_get_device(struct gpio_sim_bank *bank) 598 { 599 return bank->parent; 600 } 601 602 struct gpio_sim_hog; 603 604 struct gpio_sim_line { 605 struct config_group group; 606 607 struct gpio_sim_bank *parent; 608 struct list_head siblings; 609 610 unsigned int offset; 611 char *name; 612 613 /* There can only be one hog per line. */ 614 struct gpio_sim_hog *hog; 615 }; 616 617 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item) 618 { 619 struct config_group *group = to_config_group(item); 620 621 return container_of(group, struct gpio_sim_line, group); 622 } 623 624 static struct gpio_sim_device * 625 gpio_sim_line_get_device(struct gpio_sim_line *line) 626 { 627 struct gpio_sim_bank *bank = line->parent; 628 629 return gpio_sim_bank_get_device(bank); 630 } 631 632 struct gpio_sim_hog { 633 struct config_item item; 634 struct gpio_sim_line *parent; 635 636 char *name; 637 int dir; 638 }; 639 640 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item) 641 { 642 return container_of(item, struct gpio_sim_hog, item); 643 } 644 645 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog) 646 { 647 struct gpio_sim_line *line = hog->parent; 648 649 return gpio_sim_line_get_device(line); 650 } 651 652 static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev) 653 { 654 return !!dev->pdev; 655 } 656 657 static char *gpio_sim_strdup_trimmed(const char *str, size_t count) 658 { 659 char *dup, *trimmed; 660 661 dup = kstrndup(str, count, GFP_KERNEL); 662 if (!dup) 663 return NULL; 664 665 trimmed = strstrip(dup); 666 memmove(dup, trimmed, strlen(trimmed) + 1); 667 668 return dup; 669 } 670 671 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item, 672 char *page) 673 { 674 struct gpio_sim_device *dev = to_gpio_sim_device(item); 675 struct platform_device *pdev; 676 int ret; 677 678 mutex_lock(&dev->lock); 679 pdev = dev->pdev; 680 if (pdev) 681 ret = sprintf(page, "%s\n", dev_name(&pdev->dev)); 682 else 683 ret = sprintf(page, "gpio-sim.%d\n", dev->id); 684 mutex_unlock(&dev->lock); 685 686 return ret; 687 } 688 689 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name); 690 691 static ssize_t 692 gpio_sim_device_config_live_show(struct config_item *item, char *page) 693 { 694 struct gpio_sim_device *dev = to_gpio_sim_device(item); 695 bool live; 696 697 mutex_lock(&dev->lock); 698 live = gpio_sim_device_is_live_unlocked(dev); 699 mutex_unlock(&dev->lock); 700 701 return sprintf(page, "%c\n", live ? '1' : '0'); 702 } 703 704 static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank, 705 unsigned int *line_names_size) 706 { 707 unsigned int max_offset = 0; 708 bool has_line_names = false; 709 struct gpio_sim_line *line; 710 char **line_names; 711 712 list_for_each_entry(line, &bank->line_list, siblings) { 713 if (line->offset >= bank->num_lines) 714 continue; 715 716 if (line->name) { 717 if (line->offset > max_offset) 718 max_offset = line->offset; 719 720 /* 721 * max_offset can stay at 0 so it's not an indicator 722 * of whether line names were configured at all. 723 */ 724 has_line_names = true; 725 } 726 } 727 728 if (!has_line_names) 729 /* 730 * This is not an error - NULL means, there are no line 731 * names configured. 732 */ 733 return NULL; 734 735 *line_names_size = max_offset + 1; 736 737 line_names = kcalloc(*line_names_size, sizeof(*line_names), GFP_KERNEL); 738 if (!line_names) 739 return ERR_PTR(-ENOMEM); 740 741 list_for_each_entry(line, &bank->line_list, siblings) { 742 if (line->offset >= bank->num_lines) 743 continue; 744 745 if (line->name && (line->offset <= max_offset)) 746 line_names[line->offset] = line->name; 747 } 748 749 return line_names; 750 } 751 752 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 753 { 754 struct gpiod_hog *hog; 755 756 if (!dev->hogs) 757 return; 758 759 gpiod_remove_hogs(dev->hogs); 760 761 for (hog = dev->hogs; hog->chip_label; hog++) { 762 kfree(hog->chip_label); 763 kfree(hog->line_name); 764 } 765 766 kfree(dev->hogs); 767 dev->hogs = NULL; 768 } 769 770 static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 771 { 772 unsigned int num_hogs = 0, idx = 0; 773 struct gpio_sim_bank *bank; 774 struct gpio_sim_line *line; 775 struct gpiod_hog *hog; 776 777 list_for_each_entry(bank, &dev->bank_list, siblings) { 778 list_for_each_entry(line, &bank->line_list, siblings) { 779 if (line->offset >= bank->num_lines) 780 continue; 781 782 if (line->hog) 783 num_hogs++; 784 } 785 } 786 787 if (!num_hogs) 788 return 0; 789 790 /* Allocate one more for the sentinel. */ 791 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 792 if (!dev->hogs) 793 return -ENOMEM; 794 795 list_for_each_entry(bank, &dev->bank_list, siblings) { 796 list_for_each_entry(line, &bank->line_list, siblings) { 797 if (line->offset >= bank->num_lines) 798 continue; 799 800 if (!line->hog) 801 continue; 802 803 hog = &dev->hogs[idx++]; 804 805 /* 806 * We need to make this string manually because at this 807 * point the device doesn't exist yet and so dev_name() 808 * is not available. 809 */ 810 if (gpio_sim_bank_has_label(bank)) 811 hog->chip_label = kstrdup(bank->label, 812 GFP_KERNEL); 813 else 814 hog->chip_label = kasprintf(GFP_KERNEL, 815 "gpio-sim.%u-%pfwP", 816 dev->id, 817 bank->swnode); 818 if (!hog->chip_label) { 819 gpio_sim_remove_hogs(dev); 820 return -ENOMEM; 821 } 822 823 /* 824 * We need to duplicate this because the hog config 825 * item can be removed at any time (and we can't block 826 * it) and gpiolib doesn't make a deep copy of the hog 827 * data. 828 */ 829 if (line->hog->name) { 830 hog->line_name = kstrdup(line->hog->name, 831 GFP_KERNEL); 832 if (!hog->line_name) { 833 gpio_sim_remove_hogs(dev); 834 return -ENOMEM; 835 } 836 } 837 838 hog->chip_hwnum = line->offset; 839 hog->dflags = line->hog->dir; 840 } 841 } 842 843 gpiod_add_hogs(dev->hogs); 844 845 return 0; 846 } 847 848 static struct fwnode_handle * 849 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 850 struct fwnode_handle *parent) 851 { 852 struct property_entry properties[GPIO_SIM_PROP_MAX]; 853 unsigned int prop_idx = 0, line_names_size = 0; 854 struct fwnode_handle *swnode; 855 char **line_names; 856 857 memset(properties, 0, sizeof(properties)); 858 859 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 860 861 if (gpio_sim_bank_has_label(bank)) 862 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 863 bank->label); 864 865 line_names = gpio_sim_make_line_names(bank, &line_names_size); 866 if (IS_ERR(line_names)) 867 return ERR_CAST(line_names); 868 869 if (line_names) 870 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 871 "gpio-line-names", 872 line_names, line_names_size); 873 874 swnode = fwnode_create_software_node(properties, parent); 875 kfree(line_names); 876 return swnode; 877 } 878 879 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 880 { 881 struct fwnode_handle *child; 882 883 fwnode_for_each_child_node(swnode, child) 884 fwnode_remove_software_node(child); 885 886 fwnode_remove_software_node(swnode); 887 } 888 889 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 890 { 891 struct gpio_sim_bank *this, *pos; 892 893 list_for_each_entry(this, &dev->bank_list, siblings) { 894 list_for_each_entry(pos, &dev->bank_list, siblings) { 895 if (this == pos || (!this->label || !pos->label)) 896 continue; 897 898 if (strcmp(this->label, pos->label) == 0) 899 return true; 900 } 901 } 902 903 return false; 904 } 905 906 static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev) 907 { 908 struct platform_device_info pdevinfo; 909 struct fwnode_handle *swnode; 910 struct platform_device *pdev; 911 struct gpio_sim_bank *bank; 912 int ret; 913 914 if (list_empty(&dev->bank_list)) 915 return -ENODATA; 916 917 /* 918 * Non-unique GPIO device labels are a corner-case we don't support 919 * as it would interfere with machine hogging mechanism and has little 920 * use in real life. 921 */ 922 if (gpio_sim_bank_labels_non_unique(dev)) 923 return -EINVAL; 924 925 memset(&pdevinfo, 0, sizeof(pdevinfo)); 926 927 swnode = fwnode_create_software_node(NULL, NULL); 928 if (IS_ERR(swnode)) 929 return PTR_ERR(swnode); 930 931 list_for_each_entry(bank, &dev->bank_list, siblings) { 932 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 933 if (IS_ERR(bank->swnode)) { 934 ret = PTR_ERR(bank->swnode); 935 gpio_sim_remove_swnode_recursive(swnode); 936 return ret; 937 } 938 } 939 940 ret = gpio_sim_add_hogs(dev); 941 if (ret) { 942 gpio_sim_remove_swnode_recursive(swnode); 943 return ret; 944 } 945 946 pdevinfo.name = "gpio-sim"; 947 pdevinfo.fwnode = swnode; 948 pdevinfo.id = dev->id; 949 950 reinit_completion(&dev->probe_completion); 951 dev->driver_bound = false; 952 bus_register_notifier(&platform_bus_type, &dev->bus_notifier); 953 954 pdev = platform_device_register_full(&pdevinfo); 955 if (IS_ERR(pdev)) { 956 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 957 gpio_sim_remove_hogs(dev); 958 gpio_sim_remove_swnode_recursive(swnode); 959 return PTR_ERR(pdev); 960 } 961 962 wait_for_completion(&dev->probe_completion); 963 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 964 965 if (!dev->driver_bound) { 966 /* Probe failed, check kernel log. */ 967 platform_device_unregister(pdev); 968 gpio_sim_remove_hogs(dev); 969 gpio_sim_remove_swnode_recursive(swnode); 970 return -ENXIO; 971 } 972 973 dev->pdev = pdev; 974 975 return 0; 976 } 977 978 static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev) 979 { 980 struct fwnode_handle *swnode; 981 982 swnode = dev_fwnode(&dev->pdev->dev); 983 platform_device_unregister(dev->pdev); 984 gpio_sim_remove_hogs(dev); 985 gpio_sim_remove_swnode_recursive(swnode); 986 dev->pdev = NULL; 987 } 988 989 static ssize_t 990 gpio_sim_device_config_live_store(struct config_item *item, 991 const char *page, size_t count) 992 { 993 struct gpio_sim_device *dev = to_gpio_sim_device(item); 994 bool live; 995 int ret; 996 997 ret = kstrtobool(page, &live); 998 if (ret) 999 return ret; 1000 1001 mutex_lock(&dev->lock); 1002 1003 if ((!live && !gpio_sim_device_is_live_unlocked(dev)) || 1004 (live && gpio_sim_device_is_live_unlocked(dev))) 1005 ret = -EPERM; 1006 else if (live) 1007 ret = gpio_sim_device_activate_unlocked(dev); 1008 else 1009 gpio_sim_device_deactivate_unlocked(dev); 1010 1011 mutex_unlock(&dev->lock); 1012 1013 return ret ?: count; 1014 } 1015 1016 CONFIGFS_ATTR(gpio_sim_device_config_, live); 1017 1018 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 1019 &gpio_sim_device_config_attr_dev_name, 1020 &gpio_sim_device_config_attr_live, 1021 NULL 1022 }; 1023 1024 struct gpio_sim_chip_name_ctx { 1025 struct fwnode_handle *swnode; 1026 char *page; 1027 }; 1028 1029 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1030 { 1031 struct gpio_sim_chip_name_ctx *ctx = data; 1032 1033 /* This would be the sysfs device exported in /sys/class/gpio. */ 1034 if (dev->class) 1035 return 0; 1036 1037 if (device_match_fwnode(dev, ctx->swnode)) 1038 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1039 1040 return 0; 1041 } 1042 1043 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1044 char *page) 1045 { 1046 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1047 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1048 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1049 int ret; 1050 1051 mutex_lock(&dev->lock); 1052 if (gpio_sim_device_is_live_unlocked(dev)) 1053 ret = device_for_each_child(&dev->pdev->dev, &ctx, 1054 gpio_sim_emit_chip_name); 1055 else 1056 ret = sprintf(page, "none\n"); 1057 mutex_unlock(&dev->lock); 1058 1059 return ret; 1060 } 1061 1062 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1063 1064 static ssize_t 1065 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1066 { 1067 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1068 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1069 int ret; 1070 1071 mutex_lock(&dev->lock); 1072 ret = sprintf(page, "%s\n", bank->label ?: ""); 1073 mutex_unlock(&dev->lock); 1074 1075 return ret; 1076 } 1077 1078 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1079 const char *page, size_t count) 1080 { 1081 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1082 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1083 char *trimmed; 1084 1085 mutex_lock(&dev->lock); 1086 1087 if (gpio_sim_device_is_live_unlocked(dev)) { 1088 mutex_unlock(&dev->lock); 1089 return -EBUSY; 1090 } 1091 1092 trimmed = gpio_sim_strdup_trimmed(page, count); 1093 if (!trimmed) { 1094 mutex_unlock(&dev->lock); 1095 return -ENOMEM; 1096 } 1097 1098 kfree(bank->label); 1099 bank->label = trimmed; 1100 1101 mutex_unlock(&dev->lock); 1102 return count; 1103 } 1104 1105 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1106 1107 static ssize_t 1108 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1109 { 1110 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1111 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1112 int ret; 1113 1114 mutex_lock(&dev->lock); 1115 ret = sprintf(page, "%u\n", bank->num_lines); 1116 mutex_unlock(&dev->lock); 1117 1118 return ret; 1119 } 1120 1121 static ssize_t 1122 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1123 const char *page, size_t count) 1124 { 1125 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1126 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1127 unsigned int num_lines; 1128 int ret; 1129 1130 ret = kstrtouint(page, 0, &num_lines); 1131 if (ret) 1132 return ret; 1133 1134 if (num_lines == 0) 1135 return -EINVAL; 1136 1137 mutex_lock(&dev->lock); 1138 1139 if (gpio_sim_device_is_live_unlocked(dev)) { 1140 mutex_unlock(&dev->lock); 1141 return -EBUSY; 1142 } 1143 1144 bank->num_lines = num_lines; 1145 1146 mutex_unlock(&dev->lock); 1147 return count; 1148 } 1149 1150 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1151 1152 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1153 &gpio_sim_bank_config_attr_chip_name, 1154 &gpio_sim_bank_config_attr_label, 1155 &gpio_sim_bank_config_attr_num_lines, 1156 NULL 1157 }; 1158 1159 static ssize_t 1160 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1161 { 1162 struct gpio_sim_line *line = to_gpio_sim_line(item); 1163 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1164 int ret; 1165 1166 mutex_lock(&dev->lock); 1167 ret = sprintf(page, "%s\n", line->name ?: ""); 1168 mutex_unlock(&dev->lock); 1169 1170 return ret; 1171 } 1172 1173 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1174 const char *page, size_t count) 1175 { 1176 struct gpio_sim_line *line = to_gpio_sim_line(item); 1177 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1178 char *trimmed; 1179 1180 mutex_lock(&dev->lock); 1181 1182 if (gpio_sim_device_is_live_unlocked(dev)) { 1183 mutex_unlock(&dev->lock); 1184 return -EBUSY; 1185 } 1186 1187 trimmed = gpio_sim_strdup_trimmed(page, count); 1188 if (!trimmed) { 1189 mutex_unlock(&dev->lock); 1190 return -ENOMEM; 1191 } 1192 1193 kfree(line->name); 1194 line->name = trimmed; 1195 1196 mutex_unlock(&dev->lock); 1197 1198 return count; 1199 } 1200 1201 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1202 1203 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1204 &gpio_sim_line_config_attr_name, 1205 NULL 1206 }; 1207 1208 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1209 char *page) 1210 { 1211 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1212 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1213 int ret; 1214 1215 mutex_lock(&dev->lock); 1216 ret = sprintf(page, "%s\n", hog->name ?: ""); 1217 mutex_unlock(&dev->lock); 1218 1219 return ret; 1220 } 1221 1222 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1223 const char *page, size_t count) 1224 { 1225 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1226 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1227 char *trimmed; 1228 1229 mutex_lock(&dev->lock); 1230 1231 if (gpio_sim_device_is_live_unlocked(dev)) { 1232 mutex_unlock(&dev->lock); 1233 return -EBUSY; 1234 } 1235 1236 trimmed = gpio_sim_strdup_trimmed(page, count); 1237 if (!trimmed) { 1238 mutex_unlock(&dev->lock); 1239 return -ENOMEM; 1240 } 1241 1242 kfree(hog->name); 1243 hog->name = trimmed; 1244 1245 mutex_unlock(&dev->lock); 1246 1247 return count; 1248 } 1249 1250 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1251 1252 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1253 char *page) 1254 { 1255 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1256 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1257 char *repr; 1258 int dir; 1259 1260 mutex_lock(&dev->lock); 1261 dir = hog->dir; 1262 mutex_unlock(&dev->lock); 1263 1264 switch (dir) { 1265 case GPIOD_IN: 1266 repr = "input"; 1267 break; 1268 case GPIOD_OUT_HIGH: 1269 repr = "output-high"; 1270 break; 1271 case GPIOD_OUT_LOW: 1272 repr = "output-low"; 1273 break; 1274 default: 1275 /* This would be a programmer bug. */ 1276 WARN(1, "Unexpected hog direction value: %d", dir); 1277 return -EINVAL; 1278 } 1279 1280 return sprintf(page, "%s\n", repr); 1281 } 1282 1283 static ssize_t 1284 gpio_sim_hog_config_direction_store(struct config_item *item, 1285 const char *page, size_t count) 1286 { 1287 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1288 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1289 char *trimmed; 1290 int dir; 1291 1292 mutex_lock(&dev->lock); 1293 1294 if (gpio_sim_device_is_live_unlocked(dev)) { 1295 mutex_unlock(&dev->lock); 1296 return -EBUSY; 1297 } 1298 1299 trimmed = gpio_sim_strdup_trimmed(page, count); 1300 if (!trimmed) { 1301 mutex_unlock(&dev->lock); 1302 return -ENOMEM; 1303 } 1304 1305 if (strcmp(trimmed, "input") == 0) 1306 dir = GPIOD_IN; 1307 else if (strcmp(trimmed, "output-high") == 0) 1308 dir = GPIOD_OUT_HIGH; 1309 else if (strcmp(trimmed, "output-low") == 0) 1310 dir = GPIOD_OUT_LOW; 1311 else 1312 dir = -EINVAL; 1313 1314 kfree(trimmed); 1315 1316 if (dir < 0) { 1317 mutex_unlock(&dev->lock); 1318 return dir; 1319 } 1320 1321 hog->dir = dir; 1322 1323 mutex_unlock(&dev->lock); 1324 1325 return count; 1326 } 1327 1328 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1329 1330 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = { 1331 &gpio_sim_hog_config_attr_name, 1332 &gpio_sim_hog_config_attr_direction, 1333 NULL 1334 }; 1335 1336 static void gpio_sim_hog_config_item_release(struct config_item *item) 1337 { 1338 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1339 struct gpio_sim_line *line = hog->parent; 1340 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1341 1342 mutex_lock(&dev->lock); 1343 line->hog = NULL; 1344 mutex_unlock(&dev->lock); 1345 1346 kfree(hog->name); 1347 kfree(hog); 1348 } 1349 1350 static struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1351 .release = gpio_sim_hog_config_item_release, 1352 }; 1353 1354 static const struct config_item_type gpio_sim_hog_config_type = { 1355 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1356 .ct_attrs = gpio_sim_hog_config_attrs, 1357 .ct_owner = THIS_MODULE, 1358 }; 1359 1360 static struct config_item * 1361 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1362 { 1363 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1364 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1365 struct gpio_sim_hog *hog; 1366 1367 if (strcmp(name, "hog") != 0) 1368 return ERR_PTR(-EINVAL); 1369 1370 mutex_lock(&dev->lock); 1371 1372 hog = kzalloc(sizeof(*hog), GFP_KERNEL); 1373 if (!hog) { 1374 mutex_unlock(&dev->lock); 1375 return ERR_PTR(-ENOMEM); 1376 } 1377 1378 config_item_init_type_name(&hog->item, name, 1379 &gpio_sim_hog_config_type); 1380 1381 hog->dir = GPIOD_IN; 1382 hog->name = NULL; 1383 hog->parent = line; 1384 line->hog = hog; 1385 1386 mutex_unlock(&dev->lock); 1387 1388 return &hog->item; 1389 } 1390 1391 static void gpio_sim_line_config_group_release(struct config_item *item) 1392 { 1393 struct gpio_sim_line *line = to_gpio_sim_line(item); 1394 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1395 1396 mutex_lock(&dev->lock); 1397 list_del(&line->siblings); 1398 mutex_unlock(&dev->lock); 1399 1400 kfree(line->name); 1401 kfree(line); 1402 } 1403 1404 static struct configfs_item_operations gpio_sim_line_config_item_ops = { 1405 .release = gpio_sim_line_config_group_release, 1406 }; 1407 1408 static struct configfs_group_operations gpio_sim_line_config_group_ops = { 1409 .make_item = gpio_sim_line_config_make_hog_item, 1410 }; 1411 1412 static const struct config_item_type gpio_sim_line_config_type = { 1413 .ct_item_ops = &gpio_sim_line_config_item_ops, 1414 .ct_group_ops = &gpio_sim_line_config_group_ops, 1415 .ct_attrs = gpio_sim_line_config_attrs, 1416 .ct_owner = THIS_MODULE, 1417 }; 1418 1419 static struct config_group * 1420 gpio_sim_bank_config_make_line_group(struct config_group *group, 1421 const char *name) 1422 { 1423 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1424 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1425 struct gpio_sim_line *line; 1426 unsigned int offset; 1427 int ret, nchar; 1428 1429 ret = sscanf(name, "line%u%n", &offset, &nchar); 1430 if (ret != 1 || nchar != strlen(name)) 1431 return ERR_PTR(-EINVAL); 1432 1433 mutex_lock(&dev->lock); 1434 1435 if (gpio_sim_device_is_live_unlocked(dev)) { 1436 mutex_unlock(&dev->lock); 1437 return ERR_PTR(-EBUSY); 1438 } 1439 1440 line = kzalloc(sizeof(*line), GFP_KERNEL); 1441 if (!line) { 1442 mutex_unlock(&dev->lock); 1443 return ERR_PTR(-ENOMEM); 1444 } 1445 1446 config_group_init_type_name(&line->group, name, 1447 &gpio_sim_line_config_type); 1448 1449 line->parent = bank; 1450 line->offset = offset; 1451 list_add_tail(&line->siblings, &bank->line_list); 1452 1453 mutex_unlock(&dev->lock); 1454 1455 return &line->group; 1456 } 1457 1458 static void gpio_sim_bank_config_group_release(struct config_item *item) 1459 { 1460 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1461 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1462 1463 mutex_lock(&dev->lock); 1464 list_del(&bank->siblings); 1465 mutex_unlock(&dev->lock); 1466 1467 kfree(bank->label); 1468 kfree(bank); 1469 } 1470 1471 static struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1472 .release = gpio_sim_bank_config_group_release, 1473 }; 1474 1475 static struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1476 .make_group = gpio_sim_bank_config_make_line_group, 1477 }; 1478 1479 static const struct config_item_type gpio_sim_bank_config_group_type = { 1480 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1481 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1482 .ct_attrs = gpio_sim_bank_config_attrs, 1483 .ct_owner = THIS_MODULE, 1484 }; 1485 1486 static struct config_group * 1487 gpio_sim_device_config_make_bank_group(struct config_group *group, 1488 const char *name) 1489 { 1490 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1491 struct gpio_sim_bank *bank; 1492 1493 mutex_lock(&dev->lock); 1494 1495 if (gpio_sim_device_is_live_unlocked(dev)) { 1496 mutex_unlock(&dev->lock); 1497 return ERR_PTR(-EBUSY); 1498 } 1499 1500 bank = kzalloc(sizeof(*bank), GFP_KERNEL); 1501 if (!bank) { 1502 mutex_unlock(&dev->lock); 1503 return ERR_PTR(-ENOMEM); 1504 } 1505 1506 config_group_init_type_name(&bank->group, name, 1507 &gpio_sim_bank_config_group_type); 1508 bank->num_lines = 1; 1509 bank->parent = dev; 1510 INIT_LIST_HEAD(&bank->line_list); 1511 list_add_tail(&bank->siblings, &dev->bank_list); 1512 1513 mutex_unlock(&dev->lock); 1514 1515 return &bank->group; 1516 } 1517 1518 static void gpio_sim_device_config_group_release(struct config_item *item) 1519 { 1520 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1521 1522 mutex_lock(&dev->lock); 1523 if (gpio_sim_device_is_live_unlocked(dev)) 1524 gpio_sim_device_deactivate_unlocked(dev); 1525 mutex_unlock(&dev->lock); 1526 1527 mutex_destroy(&dev->lock); 1528 ida_free(&gpio_sim_ida, dev->id); 1529 kfree(dev); 1530 } 1531 1532 static struct configfs_item_operations gpio_sim_device_config_item_ops = { 1533 .release = gpio_sim_device_config_group_release, 1534 }; 1535 1536 static struct configfs_group_operations gpio_sim_device_config_group_ops = { 1537 .make_group = gpio_sim_device_config_make_bank_group, 1538 }; 1539 1540 static const struct config_item_type gpio_sim_device_config_group_type = { 1541 .ct_item_ops = &gpio_sim_device_config_item_ops, 1542 .ct_group_ops = &gpio_sim_device_config_group_ops, 1543 .ct_attrs = gpio_sim_device_config_attrs, 1544 .ct_owner = THIS_MODULE, 1545 }; 1546 1547 static struct config_group * 1548 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1549 { 1550 struct gpio_sim_device *dev; 1551 int id; 1552 1553 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1554 if (!dev) 1555 return ERR_PTR(-ENOMEM); 1556 1557 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1558 if (id < 0) { 1559 kfree(dev); 1560 return ERR_PTR(id); 1561 } 1562 1563 config_group_init_type_name(&dev->group, name, 1564 &gpio_sim_device_config_group_type); 1565 dev->id = id; 1566 mutex_init(&dev->lock); 1567 INIT_LIST_HEAD(&dev->bank_list); 1568 1569 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call; 1570 init_completion(&dev->probe_completion); 1571 1572 return &dev->group; 1573 } 1574 1575 static struct configfs_group_operations gpio_sim_config_group_ops = { 1576 .make_group = gpio_sim_config_make_device_group, 1577 }; 1578 1579 static const struct config_item_type gpio_sim_config_type = { 1580 .ct_group_ops = &gpio_sim_config_group_ops, 1581 .ct_owner = THIS_MODULE, 1582 }; 1583 1584 static struct configfs_subsystem gpio_sim_config_subsys = { 1585 .su_group = { 1586 .cg_item = { 1587 .ci_namebuf = "gpio-sim", 1588 .ci_type = &gpio_sim_config_type, 1589 }, 1590 }, 1591 }; 1592 1593 static int __init gpio_sim_init(void) 1594 { 1595 int ret; 1596 1597 ret = platform_driver_register(&gpio_sim_driver); 1598 if (ret) { 1599 pr_err("Error %d while registering the platform driver\n", ret); 1600 return ret; 1601 } 1602 1603 config_group_init(&gpio_sim_config_subsys.su_group); 1604 mutex_init(&gpio_sim_config_subsys.su_mutex); 1605 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1606 if (ret) { 1607 pr_err("Error %d while registering the configfs subsystem %s\n", 1608 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1609 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1610 platform_driver_unregister(&gpio_sim_driver); 1611 return ret; 1612 } 1613 1614 return 0; 1615 } 1616 module_init(gpio_sim_init); 1617 1618 static void __exit gpio_sim_exit(void) 1619 { 1620 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1621 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1622 platform_driver_unregister(&gpio_sim_driver); 1623 } 1624 module_exit(gpio_sim_exit); 1625 1626 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl"); 1627 MODULE_DESCRIPTION("GPIO Simulator Module"); 1628 MODULE_LICENSE("GPL"); 1629