1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * GPIO driver for virtio-based virtual GPIO controllers 4 * 5 * Copyright (C) 2021 metux IT consult 6 * Enrico Weigelt, metux IT consult <info@metux.net> 7 * 8 * Copyright (C) 2021 Linaro. 9 * Viresh Kumar <viresh.kumar@linaro.org> 10 */ 11 12 #include <linux/completion.h> 13 #include <linux/err.h> 14 #include <linux/gpio/driver.h> 15 #include <linux/io.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/mutex.h> 19 #include <linux/spinlock.h> 20 #include <linux/virtio_config.h> 21 #include <uapi/linux/virtio_gpio.h> 22 #include <uapi/linux/virtio_ids.h> 23 24 struct virtio_gpio_line { 25 struct mutex lock; /* Protects line operation */ 26 struct completion completion; 27 struct virtio_gpio_request req ____cacheline_aligned; 28 struct virtio_gpio_response res ____cacheline_aligned; 29 unsigned int rxlen; 30 }; 31 32 struct vgpio_irq_line { 33 u8 type; 34 bool disabled; 35 bool masked; 36 bool queued; 37 bool update_pending; 38 bool queue_pending; 39 40 struct virtio_gpio_irq_request ireq ____cacheline_aligned; 41 struct virtio_gpio_irq_response ires ____cacheline_aligned; 42 }; 43 44 struct virtio_gpio { 45 struct virtio_device *vdev; 46 struct mutex lock; /* Protects virtqueue operation */ 47 struct gpio_chip gc; 48 struct virtio_gpio_line *lines; 49 struct virtqueue *request_vq; 50 51 /* irq support */ 52 struct virtqueue *event_vq; 53 struct mutex irq_lock; /* Protects irq operation */ 54 raw_spinlock_t eventq_lock; /* Protects queuing of the buffer */ 55 struct vgpio_irq_line *irq_lines; 56 }; 57 58 static int _virtio_gpio_req(struct virtio_gpio *vgpio, u16 type, u16 gpio, 59 u8 txvalue, u8 *rxvalue, void *response, u32 rxlen) 60 { 61 struct virtio_gpio_line *line = &vgpio->lines[gpio]; 62 struct virtio_gpio_request *req = &line->req; 63 struct virtio_gpio_response *res = response; 64 struct scatterlist *sgs[2], req_sg, res_sg; 65 struct device *dev = &vgpio->vdev->dev; 66 int ret; 67 68 /* 69 * Prevent concurrent requests for the same line since we have 70 * pre-allocated request/response buffers for each GPIO line. Moreover 71 * Linux always accesses a GPIO line sequentially, so this locking shall 72 * always go through without any delays. 73 */ 74 mutex_lock(&line->lock); 75 76 req->type = cpu_to_le16(type); 77 req->gpio = cpu_to_le16(gpio); 78 req->value = cpu_to_le32(txvalue); 79 80 sg_init_one(&req_sg, req, sizeof(*req)); 81 sg_init_one(&res_sg, res, rxlen); 82 sgs[0] = &req_sg; 83 sgs[1] = &res_sg; 84 85 line->rxlen = 0; 86 reinit_completion(&line->completion); 87 88 /* 89 * Virtqueue callers need to ensure they don't call its APIs with other 90 * virtqueue operations at the same time. 91 */ 92 mutex_lock(&vgpio->lock); 93 ret = virtqueue_add_sgs(vgpio->request_vq, sgs, 1, 1, line, GFP_KERNEL); 94 if (ret) { 95 dev_err(dev, "failed to add request to vq\n"); 96 mutex_unlock(&vgpio->lock); 97 goto out; 98 } 99 100 virtqueue_kick(vgpio->request_vq); 101 mutex_unlock(&vgpio->lock); 102 103 wait_for_completion(&line->completion); 104 105 if (unlikely(res->status != VIRTIO_GPIO_STATUS_OK)) { 106 dev_err(dev, "GPIO request failed: %d\n", gpio); 107 ret = -EINVAL; 108 goto out; 109 } 110 111 if (unlikely(line->rxlen != rxlen)) { 112 dev_err(dev, "GPIO operation returned incorrect len (%u : %u)\n", 113 rxlen, line->rxlen); 114 ret = -EINVAL; 115 goto out; 116 } 117 118 if (rxvalue) 119 *rxvalue = res->value; 120 121 out: 122 mutex_unlock(&line->lock); 123 return ret; 124 } 125 126 static int virtio_gpio_req(struct virtio_gpio *vgpio, u16 type, u16 gpio, 127 u8 txvalue, u8 *rxvalue) 128 { 129 struct virtio_gpio_line *line = &vgpio->lines[gpio]; 130 struct virtio_gpio_response *res = &line->res; 131 132 return _virtio_gpio_req(vgpio, type, gpio, txvalue, rxvalue, res, 133 sizeof(*res)); 134 } 135 136 static void virtio_gpio_free(struct gpio_chip *gc, unsigned int gpio) 137 { 138 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 139 140 virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_DIRECTION, gpio, 141 VIRTIO_GPIO_DIRECTION_NONE, NULL); 142 } 143 144 static int virtio_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio) 145 { 146 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 147 u8 direction; 148 int ret; 149 150 ret = virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_DIRECTION, gpio, 0, 151 &direction); 152 if (ret) 153 return ret; 154 155 switch (direction) { 156 case VIRTIO_GPIO_DIRECTION_IN: 157 return GPIO_LINE_DIRECTION_IN; 158 case VIRTIO_GPIO_DIRECTION_OUT: 159 return GPIO_LINE_DIRECTION_OUT; 160 default: 161 return -EINVAL; 162 } 163 } 164 165 static int virtio_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio) 166 { 167 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 168 169 return virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_DIRECTION, gpio, 170 VIRTIO_GPIO_DIRECTION_IN, NULL); 171 } 172 173 static int virtio_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio, 174 int value) 175 { 176 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 177 int ret; 178 179 ret = virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_VALUE, gpio, value, NULL); 180 if (ret) 181 return ret; 182 183 return virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_DIRECTION, gpio, 184 VIRTIO_GPIO_DIRECTION_OUT, NULL); 185 } 186 187 static int virtio_gpio_get(struct gpio_chip *gc, unsigned int gpio) 188 { 189 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 190 u8 value; 191 int ret; 192 193 ret = virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_VALUE, gpio, 0, &value); 194 return ret ? ret : value; 195 } 196 197 static int virtio_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value) 198 { 199 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 200 201 return virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_VALUE, gpio, value, 202 NULL); 203 } 204 205 /* Interrupt handling */ 206 static void virtio_gpio_irq_prepare(struct virtio_gpio *vgpio, u16 gpio) 207 { 208 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[gpio]; 209 struct virtio_gpio_irq_request *ireq = &irq_line->ireq; 210 struct virtio_gpio_irq_response *ires = &irq_line->ires; 211 struct scatterlist *sgs[2], req_sg, res_sg; 212 int ret; 213 214 if (WARN_ON(irq_line->queued || irq_line->masked || irq_line->disabled)) 215 return; 216 217 ireq->gpio = cpu_to_le16(gpio); 218 sg_init_one(&req_sg, ireq, sizeof(*ireq)); 219 sg_init_one(&res_sg, ires, sizeof(*ires)); 220 sgs[0] = &req_sg; 221 sgs[1] = &res_sg; 222 223 ret = virtqueue_add_sgs(vgpio->event_vq, sgs, 1, 1, irq_line, GFP_ATOMIC); 224 if (ret) { 225 dev_err(&vgpio->vdev->dev, "failed to add request to eventq\n"); 226 return; 227 } 228 229 irq_line->queued = true; 230 virtqueue_kick(vgpio->event_vq); 231 } 232 233 static void virtio_gpio_irq_enable(struct irq_data *d) 234 { 235 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 236 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 237 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 238 239 raw_spin_lock(&vgpio->eventq_lock); 240 irq_line->disabled = false; 241 irq_line->masked = false; 242 irq_line->queue_pending = true; 243 raw_spin_unlock(&vgpio->eventq_lock); 244 245 irq_line->update_pending = true; 246 } 247 248 static void virtio_gpio_irq_disable(struct irq_data *d) 249 { 250 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 251 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 252 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 253 254 raw_spin_lock(&vgpio->eventq_lock); 255 irq_line->disabled = true; 256 irq_line->masked = true; 257 irq_line->queue_pending = false; 258 raw_spin_unlock(&vgpio->eventq_lock); 259 260 irq_line->update_pending = true; 261 } 262 263 static void virtio_gpio_irq_mask(struct irq_data *d) 264 { 265 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 266 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 267 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 268 269 raw_spin_lock(&vgpio->eventq_lock); 270 irq_line->masked = true; 271 raw_spin_unlock(&vgpio->eventq_lock); 272 } 273 274 static void virtio_gpio_irq_unmask(struct irq_data *d) 275 { 276 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 277 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 278 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 279 280 raw_spin_lock(&vgpio->eventq_lock); 281 irq_line->masked = false; 282 283 /* Queue the buffer unconditionally on unmask */ 284 virtio_gpio_irq_prepare(vgpio, d->hwirq); 285 raw_spin_unlock(&vgpio->eventq_lock); 286 } 287 288 static int virtio_gpio_irq_set_type(struct irq_data *d, unsigned int type) 289 { 290 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 291 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 292 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 293 294 switch (type) { 295 case IRQ_TYPE_EDGE_RISING: 296 type = VIRTIO_GPIO_IRQ_TYPE_EDGE_RISING; 297 break; 298 case IRQ_TYPE_EDGE_FALLING: 299 type = VIRTIO_GPIO_IRQ_TYPE_EDGE_FALLING; 300 break; 301 case IRQ_TYPE_EDGE_BOTH: 302 type = VIRTIO_GPIO_IRQ_TYPE_EDGE_BOTH; 303 break; 304 case IRQ_TYPE_LEVEL_LOW: 305 type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_LOW; 306 break; 307 case IRQ_TYPE_LEVEL_HIGH: 308 type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_HIGH; 309 break; 310 default: 311 dev_err(&vgpio->vdev->dev, "unsupported irq type: %u\n", type); 312 return -EINVAL; 313 } 314 315 irq_line->type = type; 316 irq_line->update_pending = true; 317 318 return 0; 319 } 320 321 static void virtio_gpio_irq_bus_lock(struct irq_data *d) 322 { 323 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 324 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 325 326 mutex_lock(&vgpio->irq_lock); 327 } 328 329 static void virtio_gpio_irq_bus_sync_unlock(struct irq_data *d) 330 { 331 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 332 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 333 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 334 u8 type = irq_line->disabled ? VIRTIO_GPIO_IRQ_TYPE_NONE : irq_line->type; 335 unsigned long flags; 336 337 if (irq_line->update_pending) { 338 irq_line->update_pending = false; 339 virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_IRQ_TYPE, d->hwirq, type, 340 NULL); 341 342 /* Queue the buffer only after interrupt is enabled */ 343 raw_spin_lock_irqsave(&vgpio->eventq_lock, flags); 344 if (irq_line->queue_pending) { 345 irq_line->queue_pending = false; 346 virtio_gpio_irq_prepare(vgpio, d->hwirq); 347 } 348 raw_spin_unlock_irqrestore(&vgpio->eventq_lock, flags); 349 } 350 351 mutex_unlock(&vgpio->irq_lock); 352 } 353 354 static bool ignore_irq(struct virtio_gpio *vgpio, int gpio, 355 struct vgpio_irq_line *irq_line) 356 { 357 bool ignore = false; 358 359 raw_spin_lock(&vgpio->eventq_lock); 360 irq_line->queued = false; 361 362 /* Interrupt is disabled currently */ 363 if (irq_line->masked || irq_line->disabled) { 364 ignore = true; 365 goto unlock; 366 } 367 368 /* 369 * Buffer is returned as the interrupt was disabled earlier, but is 370 * enabled again now. Requeue the buffers. 371 */ 372 if (irq_line->ires.status == VIRTIO_GPIO_IRQ_STATUS_INVALID) { 373 virtio_gpio_irq_prepare(vgpio, gpio); 374 ignore = true; 375 goto unlock; 376 } 377 378 if (WARN_ON(irq_line->ires.status != VIRTIO_GPIO_IRQ_STATUS_VALID)) 379 ignore = true; 380 381 unlock: 382 raw_spin_unlock(&vgpio->eventq_lock); 383 384 return ignore; 385 } 386 387 static void virtio_gpio_event_vq(struct virtqueue *vq) 388 { 389 struct virtio_gpio *vgpio = vq->vdev->priv; 390 struct device *dev = &vgpio->vdev->dev; 391 struct vgpio_irq_line *irq_line; 392 int gpio, ret; 393 unsigned int len; 394 395 while (true) { 396 irq_line = virtqueue_get_buf(vgpio->event_vq, &len); 397 if (!irq_line) 398 break; 399 400 if (len != sizeof(irq_line->ires)) { 401 dev_err(dev, "irq with incorrect length (%u : %u)\n", 402 len, (unsigned int)sizeof(irq_line->ires)); 403 continue; 404 } 405 406 /* 407 * Find GPIO line number from the offset of irq_line within the 408 * irq_lines block. We can also get GPIO number from 409 * irq-request, but better not to rely on a buffer returned by 410 * remote. 411 */ 412 gpio = irq_line - vgpio->irq_lines; 413 WARN_ON(gpio >= vgpio->gc.ngpio); 414 415 if (unlikely(ignore_irq(vgpio, gpio, irq_line))) 416 continue; 417 418 ret = generic_handle_domain_irq(vgpio->gc.irq.domain, gpio); 419 if (ret) 420 dev_err(dev, "failed to handle interrupt: %d\n", ret); 421 } 422 } 423 424 static void virtio_gpio_request_vq(struct virtqueue *vq) 425 { 426 struct virtio_gpio_line *line; 427 unsigned int len; 428 429 do { 430 line = virtqueue_get_buf(vq, &len); 431 if (!line) 432 return; 433 434 line->rxlen = len; 435 complete(&line->completion); 436 } while (1); 437 } 438 439 static void virtio_gpio_free_vqs(struct virtio_device *vdev) 440 { 441 virtio_reset_device(vdev); 442 vdev->config->del_vqs(vdev); 443 } 444 445 static int virtio_gpio_alloc_vqs(struct virtio_gpio *vgpio, 446 struct virtio_device *vdev) 447 { 448 struct virtqueue_info vqs_info[] = { 449 { "requestq", virtio_gpio_request_vq }, 450 { "eventq", virtio_gpio_event_vq }, 451 }; 452 struct virtqueue *vqs[2] = { NULL, NULL }; 453 int ret; 454 455 ret = virtio_find_vqs(vdev, vgpio->irq_lines ? 2 : 1, vqs, 456 vqs_info, NULL); 457 if (ret) { 458 dev_err(&vdev->dev, "failed to find vqs: %d\n", ret); 459 return ret; 460 } 461 462 if (!vqs[0]) { 463 dev_err(&vdev->dev, "failed to find requestq vq\n"); 464 goto out; 465 } 466 vgpio->request_vq = vqs[0]; 467 468 if (vgpio->irq_lines && !vqs[1]) { 469 dev_err(&vdev->dev, "failed to find eventq vq\n"); 470 goto out; 471 } 472 vgpio->event_vq = vqs[1]; 473 474 return 0; 475 476 out: 477 if (vqs[0] || vqs[1]) 478 virtio_gpio_free_vqs(vdev); 479 480 return -ENODEV; 481 } 482 483 static const char **virtio_gpio_get_names(struct virtio_gpio *vgpio, 484 u32 gpio_names_size, u16 ngpio) 485 { 486 struct virtio_gpio_response_get_names *res; 487 struct device *dev = &vgpio->vdev->dev; 488 u8 *gpio_names, *str; 489 const char **names; 490 int i, ret, len; 491 492 if (!gpio_names_size) 493 return NULL; 494 495 len = sizeof(*res) + gpio_names_size; 496 res = devm_kzalloc(dev, len, GFP_KERNEL); 497 if (!res) 498 return NULL; 499 gpio_names = res->value; 500 501 ret = _virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_NAMES, 0, 0, NULL, 502 res, len); 503 if (ret) { 504 dev_err(dev, "Failed to get GPIO names: %d\n", ret); 505 return NULL; 506 } 507 508 names = devm_kcalloc(dev, ngpio, sizeof(*names), GFP_KERNEL); 509 if (!names) 510 return NULL; 511 512 /* NULL terminate the string instead of checking it */ 513 gpio_names[gpio_names_size - 1] = '\0'; 514 515 for (i = 0, str = gpio_names; i < ngpio; i++) { 516 names[i] = str; 517 str += strlen(str) + 1; /* zero-length strings are allowed */ 518 519 if (str > gpio_names + gpio_names_size) { 520 dev_err(dev, "gpio_names block is too short (%d)\n", i); 521 return NULL; 522 } 523 } 524 525 return names; 526 } 527 528 static int virtio_gpio_probe(struct virtio_device *vdev) 529 { 530 struct device *dev = &vdev->dev; 531 struct virtio_gpio *vgpio; 532 struct irq_chip *gpio_irq_chip; 533 u32 gpio_names_size; 534 u16 ngpio; 535 int ret, i; 536 537 vgpio = devm_kzalloc(dev, sizeof(*vgpio), GFP_KERNEL); 538 if (!vgpio) 539 return -ENOMEM; 540 541 /* Read configuration */ 542 gpio_names_size = 543 virtio_cread32(vdev, offsetof(struct virtio_gpio_config, 544 gpio_names_size)); 545 ngpio = virtio_cread16(vdev, offsetof(struct virtio_gpio_config, 546 ngpio)); 547 if (!ngpio) { 548 dev_err(dev, "Number of GPIOs can't be zero\n"); 549 return -EINVAL; 550 } 551 552 vgpio->lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->lines), GFP_KERNEL); 553 if (!vgpio->lines) 554 return -ENOMEM; 555 556 for (i = 0; i < ngpio; i++) { 557 mutex_init(&vgpio->lines[i].lock); 558 init_completion(&vgpio->lines[i].completion); 559 } 560 561 mutex_init(&vgpio->lock); 562 vdev->priv = vgpio; 563 564 vgpio->vdev = vdev; 565 vgpio->gc.free = virtio_gpio_free; 566 vgpio->gc.get_direction = virtio_gpio_get_direction; 567 vgpio->gc.direction_input = virtio_gpio_direction_input; 568 vgpio->gc.direction_output = virtio_gpio_direction_output; 569 vgpio->gc.get = virtio_gpio_get; 570 vgpio->gc.set = virtio_gpio_set; 571 vgpio->gc.ngpio = ngpio; 572 vgpio->gc.base = -1; /* Allocate base dynamically */ 573 vgpio->gc.label = dev_name(dev); 574 vgpio->gc.parent = dev; 575 vgpio->gc.owner = THIS_MODULE; 576 vgpio->gc.can_sleep = true; 577 578 /* Interrupt support */ 579 if (virtio_has_feature(vdev, VIRTIO_GPIO_F_IRQ)) { 580 vgpio->irq_lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->irq_lines), GFP_KERNEL); 581 if (!vgpio->irq_lines) 582 return -ENOMEM; 583 584 gpio_irq_chip = devm_kzalloc(dev, sizeof(*gpio_irq_chip), GFP_KERNEL); 585 if (!gpio_irq_chip) 586 return -ENOMEM; 587 588 gpio_irq_chip->name = dev_name(dev); 589 gpio_irq_chip->irq_enable = virtio_gpio_irq_enable; 590 gpio_irq_chip->irq_disable = virtio_gpio_irq_disable; 591 gpio_irq_chip->irq_mask = virtio_gpio_irq_mask; 592 gpio_irq_chip->irq_unmask = virtio_gpio_irq_unmask; 593 gpio_irq_chip->irq_set_type = virtio_gpio_irq_set_type; 594 gpio_irq_chip->irq_bus_lock = virtio_gpio_irq_bus_lock; 595 gpio_irq_chip->irq_bus_sync_unlock = virtio_gpio_irq_bus_sync_unlock; 596 597 /* The event comes from the outside so no parent handler */ 598 vgpio->gc.irq.parent_handler = NULL; 599 vgpio->gc.irq.num_parents = 0; 600 vgpio->gc.irq.parents = NULL; 601 vgpio->gc.irq.default_type = IRQ_TYPE_NONE; 602 vgpio->gc.irq.handler = handle_level_irq; 603 vgpio->gc.irq.chip = gpio_irq_chip; 604 605 for (i = 0; i < ngpio; i++) { 606 vgpio->irq_lines[i].type = VIRTIO_GPIO_IRQ_TYPE_NONE; 607 vgpio->irq_lines[i].disabled = true; 608 vgpio->irq_lines[i].masked = true; 609 } 610 611 mutex_init(&vgpio->irq_lock); 612 raw_spin_lock_init(&vgpio->eventq_lock); 613 } 614 615 ret = virtio_gpio_alloc_vqs(vgpio, vdev); 616 if (ret) 617 return ret; 618 619 /* Mark the device ready to perform operations from within probe() */ 620 virtio_device_ready(vdev); 621 622 vgpio->gc.names = virtio_gpio_get_names(vgpio, gpio_names_size, ngpio); 623 624 ret = gpiochip_add_data(&vgpio->gc, vgpio); 625 if (ret) { 626 virtio_gpio_free_vqs(vdev); 627 dev_err(dev, "Failed to add virtio-gpio controller\n"); 628 } 629 630 return ret; 631 } 632 633 static void virtio_gpio_remove(struct virtio_device *vdev) 634 { 635 struct virtio_gpio *vgpio = vdev->priv; 636 637 gpiochip_remove(&vgpio->gc); 638 virtio_gpio_free_vqs(vdev); 639 } 640 641 static const struct virtio_device_id id_table[] = { 642 { VIRTIO_ID_GPIO, VIRTIO_DEV_ANY_ID }, 643 {}, 644 }; 645 MODULE_DEVICE_TABLE(virtio, id_table); 646 647 static const unsigned int features[] = { 648 VIRTIO_GPIO_F_IRQ, 649 }; 650 651 static struct virtio_driver virtio_gpio_driver = { 652 .feature_table = features, 653 .feature_table_size = ARRAY_SIZE(features), 654 .id_table = id_table, 655 .probe = virtio_gpio_probe, 656 .remove = virtio_gpio_remove, 657 .driver = { 658 .name = KBUILD_MODNAME, 659 }, 660 }; 661 module_virtio_driver(virtio_gpio_driver); 662 663 MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>"); 664 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 665 MODULE_DESCRIPTION("VirtIO GPIO driver"); 666 MODULE_LICENSE("GPL"); 667