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