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-%s", 381 dev_name(dev), fwnode_get_name(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->name) { 700 if (line->offset > max_offset) 701 max_offset = line->offset; 702 703 /* 704 * max_offset can stay at 0 so it's not an indicator 705 * of whether line names were configured at all. 706 */ 707 has_line_names = true; 708 } 709 } 710 711 if (!has_line_names) 712 /* 713 * This is not an error - NULL means, there are no line 714 * names configured. 715 */ 716 return NULL; 717 718 *line_names_size = max_offset + 1; 719 720 line_names = kcalloc(*line_names_size, sizeof(*line_names), GFP_KERNEL); 721 if (!line_names) 722 return ERR_PTR(-ENOMEM); 723 724 list_for_each_entry(line, &bank->line_list, siblings) 725 line_names[line->offset] = line->name; 726 727 return line_names; 728 } 729 730 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev) 731 { 732 struct gpiod_hog *hog; 733 734 if (!dev->hogs) 735 return; 736 737 gpiod_remove_hogs(dev->hogs); 738 739 for (hog = dev->hogs; !hog->chip_label; hog++) { 740 kfree(hog->chip_label); 741 kfree(hog->line_name); 742 } 743 744 kfree(dev->hogs); 745 dev->hogs = NULL; 746 } 747 748 static int gpio_sim_add_hogs(struct gpio_sim_device *dev) 749 { 750 unsigned int num_hogs = 0, idx = 0; 751 struct gpio_sim_bank *bank; 752 struct gpio_sim_line *line; 753 struct gpiod_hog *hog; 754 755 list_for_each_entry(bank, &dev->bank_list, siblings) { 756 list_for_each_entry(line, &bank->line_list, siblings) { 757 if (line->hog) 758 num_hogs++; 759 } 760 } 761 762 if (!num_hogs) 763 return 0; 764 765 /* Allocate one more for the sentinel. */ 766 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL); 767 if (!dev->hogs) 768 return -ENOMEM; 769 770 list_for_each_entry(bank, &dev->bank_list, siblings) { 771 list_for_each_entry(line, &bank->line_list, siblings) { 772 if (!line->hog) 773 continue; 774 775 hog = &dev->hogs[idx++]; 776 777 /* 778 * We need to make this string manually because at this 779 * point the device doesn't exist yet and so dev_name() 780 * is not available. 781 */ 782 if (gpio_sim_bank_has_label(bank)) 783 hog->chip_label = kstrdup(bank->label, 784 GFP_KERNEL); 785 else 786 hog->chip_label = kasprintf(GFP_KERNEL, 787 "gpio-sim.%u-%s", 788 dev->id, 789 fwnode_get_name( 790 bank->swnode)); 791 if (!hog->chip_label) { 792 gpio_sim_remove_hogs(dev); 793 return -ENOMEM; 794 } 795 796 /* 797 * We need to duplicate this because the hog config 798 * item can be removed at any time (and we can't block 799 * it) and gpiolib doesn't make a deep copy of the hog 800 * data. 801 */ 802 if (line->hog->name) { 803 hog->line_name = kstrdup(line->hog->name, 804 GFP_KERNEL); 805 if (!hog->line_name) { 806 gpio_sim_remove_hogs(dev); 807 return -ENOMEM; 808 } 809 } 810 811 hog->chip_hwnum = line->offset; 812 hog->dflags = line->hog->dir; 813 } 814 } 815 816 gpiod_add_hogs(dev->hogs); 817 818 return 0; 819 } 820 821 static struct fwnode_handle * 822 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank, 823 struct fwnode_handle *parent) 824 { 825 struct property_entry properties[GPIO_SIM_PROP_MAX]; 826 unsigned int prop_idx = 0, line_names_size = 0; 827 struct fwnode_handle *swnode; 828 char **line_names; 829 830 memset(properties, 0, sizeof(properties)); 831 832 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines); 833 834 if (gpio_sim_bank_has_label(bank)) 835 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label", 836 bank->label); 837 838 line_names = gpio_sim_make_line_names(bank, &line_names_size); 839 if (IS_ERR(line_names)) 840 return ERR_CAST(line_names); 841 842 if (line_names) 843 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( 844 "gpio-line-names", 845 line_names, line_names_size); 846 847 swnode = fwnode_create_software_node(properties, parent); 848 kfree(line_names); 849 return swnode; 850 } 851 852 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode) 853 { 854 struct fwnode_handle *child; 855 856 fwnode_for_each_child_node(swnode, child) 857 fwnode_remove_software_node(child); 858 859 fwnode_remove_software_node(swnode); 860 } 861 862 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev) 863 { 864 struct gpio_sim_bank *this, *pos; 865 866 list_for_each_entry(this, &dev->bank_list, siblings) { 867 list_for_each_entry(pos, &dev->bank_list, siblings) { 868 if (this == pos || (!this->label || !pos->label)) 869 continue; 870 871 if (strcmp(this->label, pos->label) == 0) 872 return true; 873 } 874 } 875 876 return false; 877 } 878 879 static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev) 880 { 881 struct platform_device_info pdevinfo; 882 struct fwnode_handle *swnode; 883 struct platform_device *pdev; 884 struct gpio_sim_bank *bank; 885 int ret; 886 887 if (list_empty(&dev->bank_list)) 888 return -ENODATA; 889 890 /* 891 * Non-unique GPIO device labels are a corner-case we don't support 892 * as it would interfere with machine hogging mechanism and has little 893 * use in real life. 894 */ 895 if (gpio_sim_bank_labels_non_unique(dev)) 896 return -EINVAL; 897 898 memset(&pdevinfo, 0, sizeof(pdevinfo)); 899 900 swnode = fwnode_create_software_node(NULL, NULL); 901 if (IS_ERR(swnode)) 902 return PTR_ERR(swnode); 903 904 list_for_each_entry(bank, &dev->bank_list, siblings) { 905 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode); 906 if (IS_ERR(bank->swnode)) { 907 ret = PTR_ERR(bank->swnode); 908 gpio_sim_remove_swnode_recursive(swnode); 909 return ret; 910 } 911 } 912 913 ret = gpio_sim_add_hogs(dev); 914 if (ret) { 915 gpio_sim_remove_swnode_recursive(swnode); 916 return ret; 917 } 918 919 pdevinfo.name = "gpio-sim"; 920 pdevinfo.fwnode = swnode; 921 pdevinfo.id = dev->id; 922 923 reinit_completion(&dev->probe_completion); 924 dev->driver_bound = false; 925 bus_register_notifier(&platform_bus_type, &dev->bus_notifier); 926 927 pdev = platform_device_register_full(&pdevinfo); 928 if (IS_ERR(pdev)) { 929 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 930 gpio_sim_remove_hogs(dev); 931 gpio_sim_remove_swnode_recursive(swnode); 932 return PTR_ERR(pdev); 933 } 934 935 wait_for_completion(&dev->probe_completion); 936 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier); 937 938 if (!dev->driver_bound) { 939 /* Probe failed, check kernel log. */ 940 platform_device_unregister(pdev); 941 gpio_sim_remove_hogs(dev); 942 gpio_sim_remove_swnode_recursive(swnode); 943 return -ENXIO; 944 } 945 946 dev->pdev = pdev; 947 948 return 0; 949 } 950 951 static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev) 952 { 953 struct fwnode_handle *swnode; 954 955 swnode = dev_fwnode(&dev->pdev->dev); 956 platform_device_unregister(dev->pdev); 957 gpio_sim_remove_swnode_recursive(swnode); 958 dev->pdev = NULL; 959 gpio_sim_remove_hogs(dev); 960 } 961 962 static ssize_t 963 gpio_sim_device_config_live_store(struct config_item *item, 964 const char *page, size_t count) 965 { 966 struct gpio_sim_device *dev = to_gpio_sim_device(item); 967 bool live; 968 int ret; 969 970 ret = kstrtobool(page, &live); 971 if (ret) 972 return ret; 973 974 mutex_lock(&dev->lock); 975 976 if ((!live && !gpio_sim_device_is_live_unlocked(dev)) || 977 (live && gpio_sim_device_is_live_unlocked(dev))) 978 ret = -EPERM; 979 else if (live) 980 ret = gpio_sim_device_activate_unlocked(dev); 981 else 982 gpio_sim_device_deactivate_unlocked(dev); 983 984 mutex_unlock(&dev->lock); 985 986 return ret ?: count; 987 } 988 989 CONFIGFS_ATTR(gpio_sim_device_config_, live); 990 991 static struct configfs_attribute *gpio_sim_device_config_attrs[] = { 992 &gpio_sim_device_config_attr_dev_name, 993 &gpio_sim_device_config_attr_live, 994 NULL 995 }; 996 997 struct gpio_sim_chip_name_ctx { 998 struct fwnode_handle *swnode; 999 char *page; 1000 }; 1001 1002 static int gpio_sim_emit_chip_name(struct device *dev, void *data) 1003 { 1004 struct gpio_sim_chip_name_ctx *ctx = data; 1005 1006 /* This would be the sysfs device exported in /sys/class/gpio. */ 1007 if (dev->class) 1008 return 0; 1009 1010 if (device_match_fwnode(dev, ctx->swnode)) 1011 return sprintf(ctx->page, "%s\n", dev_name(dev)); 1012 1013 return 0; 1014 } 1015 1016 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item, 1017 char *page) 1018 { 1019 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1020 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1021 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page }; 1022 int ret; 1023 1024 mutex_lock(&dev->lock); 1025 if (gpio_sim_device_is_live_unlocked(dev)) 1026 ret = device_for_each_child(&dev->pdev->dev, &ctx, 1027 gpio_sim_emit_chip_name); 1028 else 1029 ret = sprintf(page, "none\n"); 1030 mutex_unlock(&dev->lock); 1031 1032 return ret; 1033 } 1034 1035 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name); 1036 1037 static ssize_t 1038 gpio_sim_bank_config_label_show(struct config_item *item, char *page) 1039 { 1040 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1041 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1042 int ret; 1043 1044 mutex_lock(&dev->lock); 1045 ret = sprintf(page, "%s\n", bank->label ?: ""); 1046 mutex_unlock(&dev->lock); 1047 1048 return ret; 1049 } 1050 1051 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item, 1052 const char *page, size_t count) 1053 { 1054 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1055 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1056 char *trimmed; 1057 1058 mutex_lock(&dev->lock); 1059 1060 if (gpio_sim_device_is_live_unlocked(dev)) { 1061 mutex_unlock(&dev->lock); 1062 return -EBUSY; 1063 } 1064 1065 trimmed = gpio_sim_strdup_trimmed(page, count); 1066 if (!trimmed) { 1067 mutex_unlock(&dev->lock); 1068 return -ENOMEM; 1069 } 1070 1071 kfree(bank->label); 1072 bank->label = trimmed; 1073 1074 mutex_unlock(&dev->lock); 1075 return count; 1076 } 1077 1078 CONFIGFS_ATTR(gpio_sim_bank_config_, label); 1079 1080 static ssize_t 1081 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page) 1082 { 1083 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1084 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1085 int ret; 1086 1087 mutex_lock(&dev->lock); 1088 ret = sprintf(page, "%u\n", bank->num_lines); 1089 mutex_unlock(&dev->lock); 1090 1091 return ret; 1092 } 1093 1094 static ssize_t 1095 gpio_sim_bank_config_num_lines_store(struct config_item *item, 1096 const char *page, size_t count) 1097 { 1098 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1099 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1100 unsigned int num_lines; 1101 int ret; 1102 1103 ret = kstrtouint(page, 0, &num_lines); 1104 if (ret) 1105 return ret; 1106 1107 if (num_lines == 0) 1108 return -EINVAL; 1109 1110 mutex_lock(&dev->lock); 1111 1112 if (gpio_sim_device_is_live_unlocked(dev)) { 1113 mutex_unlock(&dev->lock); 1114 return -EBUSY; 1115 } 1116 1117 bank->num_lines = num_lines; 1118 1119 mutex_unlock(&dev->lock); 1120 return count; 1121 } 1122 1123 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines); 1124 1125 static struct configfs_attribute *gpio_sim_bank_config_attrs[] = { 1126 &gpio_sim_bank_config_attr_chip_name, 1127 &gpio_sim_bank_config_attr_label, 1128 &gpio_sim_bank_config_attr_num_lines, 1129 NULL 1130 }; 1131 1132 static ssize_t 1133 gpio_sim_line_config_name_show(struct config_item *item, char *page) 1134 { 1135 struct gpio_sim_line *line = to_gpio_sim_line(item); 1136 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1137 int ret; 1138 1139 mutex_lock(&dev->lock); 1140 ret = sprintf(page, "%s\n", line->name ?: ""); 1141 mutex_unlock(&dev->lock); 1142 1143 return ret; 1144 } 1145 1146 static ssize_t gpio_sim_line_config_name_store(struct config_item *item, 1147 const char *page, size_t count) 1148 { 1149 struct gpio_sim_line *line = to_gpio_sim_line(item); 1150 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1151 char *trimmed; 1152 1153 mutex_lock(&dev->lock); 1154 1155 if (gpio_sim_device_is_live_unlocked(dev)) { 1156 mutex_unlock(&dev->lock); 1157 return -EBUSY; 1158 } 1159 1160 trimmed = gpio_sim_strdup_trimmed(page, count); 1161 if (!trimmed) { 1162 mutex_unlock(&dev->lock); 1163 return -ENOMEM; 1164 } 1165 1166 kfree(line->name); 1167 line->name = trimmed; 1168 1169 mutex_unlock(&dev->lock); 1170 1171 return count; 1172 } 1173 1174 CONFIGFS_ATTR(gpio_sim_line_config_, name); 1175 1176 static struct configfs_attribute *gpio_sim_line_config_attrs[] = { 1177 &gpio_sim_line_config_attr_name, 1178 NULL 1179 }; 1180 1181 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item, 1182 char *page) 1183 { 1184 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1185 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1186 int ret; 1187 1188 mutex_lock(&dev->lock); 1189 ret = sprintf(page, "%s\n", hog->name ?: ""); 1190 mutex_unlock(&dev->lock); 1191 1192 return ret; 1193 } 1194 1195 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item, 1196 const char *page, size_t count) 1197 { 1198 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1199 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1200 char *trimmed; 1201 1202 mutex_lock(&dev->lock); 1203 1204 if (gpio_sim_device_is_live_unlocked(dev)) { 1205 mutex_unlock(&dev->lock); 1206 return -EBUSY; 1207 } 1208 1209 trimmed = gpio_sim_strdup_trimmed(page, count); 1210 if (!trimmed) { 1211 mutex_unlock(&dev->lock); 1212 return -ENOMEM; 1213 } 1214 1215 kfree(hog->name); 1216 hog->name = trimmed; 1217 1218 mutex_unlock(&dev->lock); 1219 1220 return count; 1221 } 1222 1223 CONFIGFS_ATTR(gpio_sim_hog_config_, name); 1224 1225 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item, 1226 char *page) 1227 { 1228 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1229 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1230 char *repr; 1231 int dir; 1232 1233 mutex_lock(&dev->lock); 1234 dir = hog->dir; 1235 mutex_unlock(&dev->lock); 1236 1237 switch (dir) { 1238 case GPIOD_IN: 1239 repr = "input"; 1240 break; 1241 case GPIOD_OUT_HIGH: 1242 repr = "output-high"; 1243 break; 1244 case GPIOD_OUT_LOW: 1245 repr = "output-low"; 1246 break; 1247 default: 1248 /* This would be a programmer bug. */ 1249 WARN(1, "Unexpected hog direction value: %d", dir); 1250 return -EINVAL; 1251 } 1252 1253 return sprintf(page, "%s\n", repr); 1254 } 1255 1256 static ssize_t 1257 gpio_sim_hog_config_direction_store(struct config_item *item, 1258 const char *page, size_t count) 1259 { 1260 struct gpio_sim_hog *hog = to_gpio_sim_hog(item); 1261 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog); 1262 char *trimmed; 1263 int dir; 1264 1265 mutex_lock(&dev->lock); 1266 1267 if (gpio_sim_device_is_live_unlocked(dev)) { 1268 mutex_unlock(&dev->lock); 1269 return -EBUSY; 1270 } 1271 1272 trimmed = gpio_sim_strdup_trimmed(page, count); 1273 if (!trimmed) { 1274 mutex_unlock(&dev->lock); 1275 return -ENOMEM; 1276 } 1277 1278 if (strcmp(trimmed, "input") == 0) 1279 dir = GPIOD_IN; 1280 else if (strcmp(trimmed, "output-high") == 0) 1281 dir = GPIOD_OUT_HIGH; 1282 else if (strcmp(trimmed, "output-low") == 0) 1283 dir = GPIOD_OUT_LOW; 1284 else 1285 dir = -EINVAL; 1286 1287 kfree(trimmed); 1288 1289 if (dir < 0) { 1290 mutex_unlock(&dev->lock); 1291 return dir; 1292 } 1293 1294 hog->dir = dir; 1295 1296 mutex_unlock(&dev->lock); 1297 1298 return count; 1299 } 1300 1301 CONFIGFS_ATTR(gpio_sim_hog_config_, direction); 1302 1303 static 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 1309 static 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 mutex_lock(&dev->lock); 1316 line->hog = NULL; 1317 mutex_unlock(&dev->lock); 1318 1319 kfree(hog->name); 1320 kfree(hog); 1321 } 1322 1323 static struct configfs_item_operations gpio_sim_hog_config_item_ops = { 1324 .release = gpio_sim_hog_config_item_release, 1325 }; 1326 1327 static const struct config_item_type gpio_sim_hog_config_type = { 1328 .ct_item_ops = &gpio_sim_hog_config_item_ops, 1329 .ct_attrs = gpio_sim_hog_config_attrs, 1330 .ct_owner = THIS_MODULE, 1331 }; 1332 1333 static struct config_item * 1334 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name) 1335 { 1336 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item); 1337 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1338 struct gpio_sim_hog *hog; 1339 1340 if (strcmp(name, "hog") != 0) 1341 return ERR_PTR(-EINVAL); 1342 1343 mutex_lock(&dev->lock); 1344 1345 hog = kzalloc(sizeof(*hog), GFP_KERNEL); 1346 if (!hog) { 1347 mutex_unlock(&dev->lock); 1348 return ERR_PTR(-ENOMEM); 1349 } 1350 1351 config_item_init_type_name(&hog->item, name, 1352 &gpio_sim_hog_config_type); 1353 1354 hog->dir = GPIOD_IN; 1355 hog->name = NULL; 1356 hog->parent = line; 1357 line->hog = hog; 1358 1359 mutex_unlock(&dev->lock); 1360 1361 return &hog->item; 1362 } 1363 1364 static void gpio_sim_line_config_group_release(struct config_item *item) 1365 { 1366 struct gpio_sim_line *line = to_gpio_sim_line(item); 1367 struct gpio_sim_device *dev = gpio_sim_line_get_device(line); 1368 1369 mutex_lock(&dev->lock); 1370 list_del(&line->siblings); 1371 mutex_unlock(&dev->lock); 1372 1373 kfree(line->name); 1374 kfree(line); 1375 } 1376 1377 static struct configfs_item_operations gpio_sim_line_config_item_ops = { 1378 .release = gpio_sim_line_config_group_release, 1379 }; 1380 1381 static struct configfs_group_operations gpio_sim_line_config_group_ops = { 1382 .make_item = gpio_sim_line_config_make_hog_item, 1383 }; 1384 1385 static const struct config_item_type gpio_sim_line_config_type = { 1386 .ct_item_ops = &gpio_sim_line_config_item_ops, 1387 .ct_group_ops = &gpio_sim_line_config_group_ops, 1388 .ct_attrs = gpio_sim_line_config_attrs, 1389 .ct_owner = THIS_MODULE, 1390 }; 1391 1392 static struct config_group * 1393 gpio_sim_bank_config_make_line_group(struct config_group *group, 1394 const char *name) 1395 { 1396 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item); 1397 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1398 struct gpio_sim_line *line; 1399 unsigned int offset; 1400 int ret, nchar; 1401 1402 ret = sscanf(name, "line%u%n", &offset, &nchar); 1403 if (ret != 1 || nchar != strlen(name)) 1404 return ERR_PTR(-EINVAL); 1405 1406 mutex_lock(&dev->lock); 1407 1408 if (gpio_sim_device_is_live_unlocked(dev)) { 1409 mutex_unlock(&dev->lock); 1410 return ERR_PTR(-EBUSY); 1411 } 1412 1413 line = kzalloc(sizeof(*line), GFP_KERNEL); 1414 if (!line) { 1415 mutex_unlock(&dev->lock); 1416 return ERR_PTR(-ENOMEM); 1417 } 1418 1419 config_group_init_type_name(&line->group, name, 1420 &gpio_sim_line_config_type); 1421 1422 line->parent = bank; 1423 line->offset = offset; 1424 list_add_tail(&line->siblings, &bank->line_list); 1425 1426 mutex_unlock(&dev->lock); 1427 1428 return &line->group; 1429 } 1430 1431 static void gpio_sim_bank_config_group_release(struct config_item *item) 1432 { 1433 struct gpio_sim_bank *bank = to_gpio_sim_bank(item); 1434 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank); 1435 1436 mutex_lock(&dev->lock); 1437 list_del(&bank->siblings); 1438 mutex_unlock(&dev->lock); 1439 1440 kfree(bank->label); 1441 kfree(bank); 1442 } 1443 1444 static struct configfs_item_operations gpio_sim_bank_config_item_ops = { 1445 .release = gpio_sim_bank_config_group_release, 1446 }; 1447 1448 static struct configfs_group_operations gpio_sim_bank_config_group_ops = { 1449 .make_group = gpio_sim_bank_config_make_line_group, 1450 }; 1451 1452 static const struct config_item_type gpio_sim_bank_config_group_type = { 1453 .ct_item_ops = &gpio_sim_bank_config_item_ops, 1454 .ct_group_ops = &gpio_sim_bank_config_group_ops, 1455 .ct_attrs = gpio_sim_bank_config_attrs, 1456 .ct_owner = THIS_MODULE, 1457 }; 1458 1459 static struct config_group * 1460 gpio_sim_device_config_make_bank_group(struct config_group *group, 1461 const char *name) 1462 { 1463 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item); 1464 struct gpio_sim_bank *bank; 1465 1466 mutex_lock(&dev->lock); 1467 1468 if (gpio_sim_device_is_live_unlocked(dev)) { 1469 mutex_unlock(&dev->lock); 1470 return ERR_PTR(-EBUSY); 1471 } 1472 1473 bank = kzalloc(sizeof(*bank), GFP_KERNEL); 1474 if (!bank) { 1475 mutex_unlock(&dev->lock); 1476 return ERR_PTR(-ENOMEM); 1477 } 1478 1479 config_group_init_type_name(&bank->group, name, 1480 &gpio_sim_bank_config_group_type); 1481 bank->num_lines = 1; 1482 bank->parent = dev; 1483 INIT_LIST_HEAD(&bank->line_list); 1484 list_add_tail(&bank->siblings, &dev->bank_list); 1485 1486 mutex_unlock(&dev->lock); 1487 1488 return &bank->group; 1489 } 1490 1491 static void gpio_sim_device_config_group_release(struct config_item *item) 1492 { 1493 struct gpio_sim_device *dev = to_gpio_sim_device(item); 1494 1495 mutex_lock(&dev->lock); 1496 if (gpio_sim_device_is_live_unlocked(dev)) 1497 gpio_sim_device_deactivate_unlocked(dev); 1498 mutex_unlock(&dev->lock); 1499 1500 mutex_destroy(&dev->lock); 1501 ida_free(&gpio_sim_ida, dev->id); 1502 kfree(dev); 1503 } 1504 1505 static struct configfs_item_operations gpio_sim_device_config_item_ops = { 1506 .release = gpio_sim_device_config_group_release, 1507 }; 1508 1509 static struct configfs_group_operations gpio_sim_device_config_group_ops = { 1510 .make_group = gpio_sim_device_config_make_bank_group, 1511 }; 1512 1513 static const struct config_item_type gpio_sim_device_config_group_type = { 1514 .ct_item_ops = &gpio_sim_device_config_item_ops, 1515 .ct_group_ops = &gpio_sim_device_config_group_ops, 1516 .ct_attrs = gpio_sim_device_config_attrs, 1517 .ct_owner = THIS_MODULE, 1518 }; 1519 1520 static struct config_group * 1521 gpio_sim_config_make_device_group(struct config_group *group, const char *name) 1522 { 1523 struct gpio_sim_device *dev; 1524 int id; 1525 1526 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1527 if (!dev) 1528 return ERR_PTR(-ENOMEM); 1529 1530 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); 1531 if (id < 0) { 1532 kfree(dev); 1533 return ERR_PTR(id); 1534 } 1535 1536 config_group_init_type_name(&dev->group, name, 1537 &gpio_sim_device_config_group_type); 1538 dev->id = id; 1539 mutex_init(&dev->lock); 1540 INIT_LIST_HEAD(&dev->bank_list); 1541 1542 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call; 1543 init_completion(&dev->probe_completion); 1544 1545 return &dev->group; 1546 } 1547 1548 static struct configfs_group_operations gpio_sim_config_group_ops = { 1549 .make_group = gpio_sim_config_make_device_group, 1550 }; 1551 1552 static const struct config_item_type gpio_sim_config_type = { 1553 .ct_group_ops = &gpio_sim_config_group_ops, 1554 .ct_owner = THIS_MODULE, 1555 }; 1556 1557 static struct configfs_subsystem gpio_sim_config_subsys = { 1558 .su_group = { 1559 .cg_item = { 1560 .ci_namebuf = "gpio-sim", 1561 .ci_type = &gpio_sim_config_type, 1562 }, 1563 }, 1564 }; 1565 1566 static int __init gpio_sim_init(void) 1567 { 1568 int ret; 1569 1570 ret = platform_driver_register(&gpio_sim_driver); 1571 if (ret) { 1572 pr_err("Error %d while registering the platform driver\n", ret); 1573 return ret; 1574 } 1575 1576 config_group_init(&gpio_sim_config_subsys.su_group); 1577 mutex_init(&gpio_sim_config_subsys.su_mutex); 1578 ret = configfs_register_subsystem(&gpio_sim_config_subsys); 1579 if (ret) { 1580 pr_err("Error %d while registering the configfs subsystem %s\n", 1581 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf); 1582 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1583 platform_driver_unregister(&gpio_sim_driver); 1584 return ret; 1585 } 1586 1587 return 0; 1588 } 1589 module_init(gpio_sim_init); 1590 1591 static void __exit gpio_sim_exit(void) 1592 { 1593 configfs_unregister_subsystem(&gpio_sim_config_subsys); 1594 mutex_destroy(&gpio_sim_config_subsys.su_mutex); 1595 platform_driver_unregister(&gpio_sim_driver); 1596 } 1597 module_exit(gpio_sim_exit); 1598 1599 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl"); 1600 MODULE_DESCRIPTION("GPIO Simulator Module"); 1601 MODULE_LICENSE("GPL"); 1602