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 void virtio_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value) 198 { 199 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 200 201 virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_VALUE, gpio, value, NULL); 202 } 203 204 /* Interrupt handling */ 205 static void virtio_gpio_irq_prepare(struct virtio_gpio *vgpio, u16 gpio) 206 { 207 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[gpio]; 208 struct virtio_gpio_irq_request *ireq = &irq_line->ireq; 209 struct virtio_gpio_irq_response *ires = &irq_line->ires; 210 struct scatterlist *sgs[2], req_sg, res_sg; 211 int ret; 212 213 if (WARN_ON(irq_line->queued || irq_line->masked || irq_line->disabled)) 214 return; 215 216 ireq->gpio = cpu_to_le16(gpio); 217 sg_init_one(&req_sg, ireq, sizeof(*ireq)); 218 sg_init_one(&res_sg, ires, sizeof(*ires)); 219 sgs[0] = &req_sg; 220 sgs[1] = &res_sg; 221 222 ret = virtqueue_add_sgs(vgpio->event_vq, sgs, 1, 1, irq_line, GFP_ATOMIC); 223 if (ret) { 224 dev_err(&vgpio->vdev->dev, "failed to add request to eventq\n"); 225 return; 226 } 227 228 irq_line->queued = true; 229 virtqueue_kick(vgpio->event_vq); 230 } 231 232 static void virtio_gpio_irq_enable(struct irq_data *d) 233 { 234 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 235 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 236 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 237 238 raw_spin_lock(&vgpio->eventq_lock); 239 irq_line->disabled = false; 240 irq_line->masked = false; 241 irq_line->queue_pending = true; 242 raw_spin_unlock(&vgpio->eventq_lock); 243 244 irq_line->update_pending = true; 245 } 246 247 static void virtio_gpio_irq_disable(struct irq_data *d) 248 { 249 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 250 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 251 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 252 253 raw_spin_lock(&vgpio->eventq_lock); 254 irq_line->disabled = true; 255 irq_line->masked = true; 256 irq_line->queue_pending = false; 257 raw_spin_unlock(&vgpio->eventq_lock); 258 259 irq_line->update_pending = true; 260 } 261 262 static void virtio_gpio_irq_mask(struct irq_data *d) 263 { 264 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 265 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 266 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 267 268 raw_spin_lock(&vgpio->eventq_lock); 269 irq_line->masked = true; 270 raw_spin_unlock(&vgpio->eventq_lock); 271 } 272 273 static void virtio_gpio_irq_unmask(struct irq_data *d) 274 { 275 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 276 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 277 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 278 279 raw_spin_lock(&vgpio->eventq_lock); 280 irq_line->masked = false; 281 282 /* Queue the buffer unconditionally on unmask */ 283 virtio_gpio_irq_prepare(vgpio, d->hwirq); 284 raw_spin_unlock(&vgpio->eventq_lock); 285 } 286 287 static int virtio_gpio_irq_set_type(struct irq_data *d, unsigned int type) 288 { 289 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 290 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 291 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 292 293 switch (type) { 294 case IRQ_TYPE_EDGE_RISING: 295 type = VIRTIO_GPIO_IRQ_TYPE_EDGE_RISING; 296 break; 297 case IRQ_TYPE_EDGE_FALLING: 298 type = VIRTIO_GPIO_IRQ_TYPE_EDGE_FALLING; 299 break; 300 case IRQ_TYPE_EDGE_BOTH: 301 type = VIRTIO_GPIO_IRQ_TYPE_EDGE_BOTH; 302 break; 303 case IRQ_TYPE_LEVEL_LOW: 304 type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_LOW; 305 break; 306 case IRQ_TYPE_LEVEL_HIGH: 307 type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_HIGH; 308 break; 309 default: 310 dev_err(&vgpio->vdev->dev, "unsupported irq type: %u\n", type); 311 return -EINVAL; 312 } 313 314 irq_line->type = type; 315 irq_line->update_pending = true; 316 317 return 0; 318 } 319 320 static void virtio_gpio_irq_bus_lock(struct irq_data *d) 321 { 322 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 323 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 324 325 mutex_lock(&vgpio->irq_lock); 326 } 327 328 static void virtio_gpio_irq_bus_sync_unlock(struct irq_data *d) 329 { 330 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 331 struct virtio_gpio *vgpio = gpiochip_get_data(gc); 332 struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq]; 333 u8 type = irq_line->disabled ? VIRTIO_GPIO_IRQ_TYPE_NONE : irq_line->type; 334 unsigned long flags; 335 336 if (irq_line->update_pending) { 337 irq_line->update_pending = false; 338 virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_IRQ_TYPE, d->hwirq, type, 339 NULL); 340 341 /* Queue the buffer only after interrupt is enabled */ 342 raw_spin_lock_irqsave(&vgpio->eventq_lock, flags); 343 if (irq_line->queue_pending) { 344 irq_line->queue_pending = false; 345 virtio_gpio_irq_prepare(vgpio, d->hwirq); 346 } 347 raw_spin_unlock_irqrestore(&vgpio->eventq_lock, flags); 348 } 349 350 mutex_unlock(&vgpio->irq_lock); 351 } 352 353 static bool ignore_irq(struct virtio_gpio *vgpio, int gpio, 354 struct vgpio_irq_line *irq_line) 355 { 356 bool ignore = false; 357 358 raw_spin_lock(&vgpio->eventq_lock); 359 irq_line->queued = false; 360 361 /* Interrupt is disabled currently */ 362 if (irq_line->masked || irq_line->disabled) { 363 ignore = true; 364 goto unlock; 365 } 366 367 /* 368 * Buffer is returned as the interrupt was disabled earlier, but is 369 * enabled again now. Requeue the buffers. 370 */ 371 if (irq_line->ires.status == VIRTIO_GPIO_IRQ_STATUS_INVALID) { 372 virtio_gpio_irq_prepare(vgpio, gpio); 373 ignore = true; 374 goto unlock; 375 } 376 377 if (WARN_ON(irq_line->ires.status != VIRTIO_GPIO_IRQ_STATUS_VALID)) 378 ignore = true; 379 380 unlock: 381 raw_spin_unlock(&vgpio->eventq_lock); 382 383 return ignore; 384 } 385 386 static void virtio_gpio_event_vq(struct virtqueue *vq) 387 { 388 struct virtio_gpio *vgpio = vq->vdev->priv; 389 struct device *dev = &vgpio->vdev->dev; 390 struct vgpio_irq_line *irq_line; 391 int gpio, ret; 392 unsigned int len; 393 394 while (true) { 395 irq_line = virtqueue_get_buf(vgpio->event_vq, &len); 396 if (!irq_line) 397 break; 398 399 if (len != sizeof(irq_line->ires)) { 400 dev_err(dev, "irq with incorrect length (%u : %u)\n", 401 len, (unsigned int)sizeof(irq_line->ires)); 402 continue; 403 } 404 405 /* 406 * Find GPIO line number from the offset of irq_line within the 407 * irq_lines block. We can also get GPIO number from 408 * irq-request, but better not to rely on a buffer returned by 409 * remote. 410 */ 411 gpio = irq_line - vgpio->irq_lines; 412 WARN_ON(gpio >= vgpio->gc.ngpio); 413 414 if (unlikely(ignore_irq(vgpio, gpio, irq_line))) 415 continue; 416 417 ret = generic_handle_domain_irq(vgpio->gc.irq.domain, gpio); 418 if (ret) 419 dev_err(dev, "failed to handle interrupt: %d\n", ret); 420 } 421 } 422 423 static void virtio_gpio_request_vq(struct virtqueue *vq) 424 { 425 struct virtio_gpio_line *line; 426 unsigned int len; 427 428 do { 429 line = virtqueue_get_buf(vq, &len); 430 if (!line) 431 return; 432 433 line->rxlen = len; 434 complete(&line->completion); 435 } while (1); 436 } 437 438 static void virtio_gpio_free_vqs(struct virtio_device *vdev) 439 { 440 virtio_reset_device(vdev); 441 vdev->config->del_vqs(vdev); 442 } 443 444 static int virtio_gpio_alloc_vqs(struct virtio_gpio *vgpio, 445 struct virtio_device *vdev) 446 { 447 struct virtqueue_info vqs_info[] = { 448 { "requestq", virtio_gpio_request_vq }, 449 { "eventq", virtio_gpio_event_vq }, 450 }; 451 struct virtqueue *vqs[2] = { NULL, NULL }; 452 int ret; 453 454 ret = virtio_find_vqs(vdev, vgpio->irq_lines ? 2 : 1, vqs, 455 vqs_info, NULL); 456 if (ret) { 457 dev_err(&vdev->dev, "failed to find vqs: %d\n", ret); 458 return ret; 459 } 460 461 if (!vqs[0]) { 462 dev_err(&vdev->dev, "failed to find requestq vq\n"); 463 goto out; 464 } 465 vgpio->request_vq = vqs[0]; 466 467 if (vgpio->irq_lines && !vqs[1]) { 468 dev_err(&vdev->dev, "failed to find eventq vq\n"); 469 goto out; 470 } 471 vgpio->event_vq = vqs[1]; 472 473 return 0; 474 475 out: 476 if (vqs[0] || vqs[1]) 477 virtio_gpio_free_vqs(vdev); 478 479 return -ENODEV; 480 } 481 482 static const char **virtio_gpio_get_names(struct virtio_gpio *vgpio, 483 u32 gpio_names_size, u16 ngpio) 484 { 485 struct virtio_gpio_response_get_names *res; 486 struct device *dev = &vgpio->vdev->dev; 487 u8 *gpio_names, *str; 488 const char **names; 489 int i, ret, len; 490 491 if (!gpio_names_size) 492 return NULL; 493 494 len = sizeof(*res) + gpio_names_size; 495 res = devm_kzalloc(dev, len, GFP_KERNEL); 496 if (!res) 497 return NULL; 498 gpio_names = res->value; 499 500 ret = _virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_NAMES, 0, 0, NULL, 501 res, len); 502 if (ret) { 503 dev_err(dev, "Failed to get GPIO names: %d\n", ret); 504 return NULL; 505 } 506 507 names = devm_kcalloc(dev, ngpio, sizeof(*names), GFP_KERNEL); 508 if (!names) 509 return NULL; 510 511 /* NULL terminate the string instead of checking it */ 512 gpio_names[gpio_names_size - 1] = '\0'; 513 514 for (i = 0, str = gpio_names; i < ngpio; i++) { 515 names[i] = str; 516 str += strlen(str) + 1; /* zero-length strings are allowed */ 517 518 if (str > gpio_names + gpio_names_size) { 519 dev_err(dev, "gpio_names block is too short (%d)\n", i); 520 return NULL; 521 } 522 } 523 524 return names; 525 } 526 527 static int virtio_gpio_probe(struct virtio_device *vdev) 528 { 529 struct virtio_gpio_config config; 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 virtio_cread_bytes(vdev, 0, &config, sizeof(config)); 543 gpio_names_size = le32_to_cpu(config.gpio_names_size); 544 ngpio = le16_to_cpu(config.ngpio); 545 if (!ngpio) { 546 dev_err(dev, "Number of GPIOs can't be zero\n"); 547 return -EINVAL; 548 } 549 550 vgpio->lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->lines), GFP_KERNEL); 551 if (!vgpio->lines) 552 return -ENOMEM; 553 554 for (i = 0; i < ngpio; i++) { 555 mutex_init(&vgpio->lines[i].lock); 556 init_completion(&vgpio->lines[i].completion); 557 } 558 559 mutex_init(&vgpio->lock); 560 vdev->priv = vgpio; 561 562 vgpio->vdev = vdev; 563 vgpio->gc.free = virtio_gpio_free; 564 vgpio->gc.get_direction = virtio_gpio_get_direction; 565 vgpio->gc.direction_input = virtio_gpio_direction_input; 566 vgpio->gc.direction_output = virtio_gpio_direction_output; 567 vgpio->gc.get = virtio_gpio_get; 568 vgpio->gc.set = virtio_gpio_set; 569 vgpio->gc.ngpio = ngpio; 570 vgpio->gc.base = -1; /* Allocate base dynamically */ 571 vgpio->gc.label = dev_name(dev); 572 vgpio->gc.parent = dev; 573 vgpio->gc.owner = THIS_MODULE; 574 vgpio->gc.can_sleep = true; 575 576 /* Interrupt support */ 577 if (virtio_has_feature(vdev, VIRTIO_GPIO_F_IRQ)) { 578 vgpio->irq_lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->irq_lines), GFP_KERNEL); 579 if (!vgpio->irq_lines) 580 return -ENOMEM; 581 582 gpio_irq_chip = devm_kzalloc(dev, sizeof(*gpio_irq_chip), GFP_KERNEL); 583 if (!gpio_irq_chip) 584 return -ENOMEM; 585 586 gpio_irq_chip->name = dev_name(dev); 587 gpio_irq_chip->irq_enable = virtio_gpio_irq_enable; 588 gpio_irq_chip->irq_disable = virtio_gpio_irq_disable; 589 gpio_irq_chip->irq_mask = virtio_gpio_irq_mask; 590 gpio_irq_chip->irq_unmask = virtio_gpio_irq_unmask; 591 gpio_irq_chip->irq_set_type = virtio_gpio_irq_set_type; 592 gpio_irq_chip->irq_bus_lock = virtio_gpio_irq_bus_lock; 593 gpio_irq_chip->irq_bus_sync_unlock = virtio_gpio_irq_bus_sync_unlock; 594 595 /* The event comes from the outside so no parent handler */ 596 vgpio->gc.irq.parent_handler = NULL; 597 vgpio->gc.irq.num_parents = 0; 598 vgpio->gc.irq.parents = NULL; 599 vgpio->gc.irq.default_type = IRQ_TYPE_NONE; 600 vgpio->gc.irq.handler = handle_level_irq; 601 vgpio->gc.irq.chip = gpio_irq_chip; 602 603 for (i = 0; i < ngpio; i++) { 604 vgpio->irq_lines[i].type = VIRTIO_GPIO_IRQ_TYPE_NONE; 605 vgpio->irq_lines[i].disabled = true; 606 vgpio->irq_lines[i].masked = true; 607 } 608 609 mutex_init(&vgpio->irq_lock); 610 raw_spin_lock_init(&vgpio->eventq_lock); 611 } 612 613 ret = virtio_gpio_alloc_vqs(vgpio, vdev); 614 if (ret) 615 return ret; 616 617 /* Mark the device ready to perform operations from within probe() */ 618 virtio_device_ready(vdev); 619 620 vgpio->gc.names = virtio_gpio_get_names(vgpio, gpio_names_size, ngpio); 621 622 ret = gpiochip_add_data(&vgpio->gc, vgpio); 623 if (ret) { 624 virtio_gpio_free_vqs(vdev); 625 dev_err(dev, "Failed to add virtio-gpio controller\n"); 626 } 627 628 return ret; 629 } 630 631 static void virtio_gpio_remove(struct virtio_device *vdev) 632 { 633 struct virtio_gpio *vgpio = vdev->priv; 634 635 gpiochip_remove(&vgpio->gc); 636 virtio_gpio_free_vqs(vdev); 637 } 638 639 static const struct virtio_device_id id_table[] = { 640 { VIRTIO_ID_GPIO, VIRTIO_DEV_ANY_ID }, 641 {}, 642 }; 643 MODULE_DEVICE_TABLE(virtio, id_table); 644 645 static const unsigned int features[] = { 646 VIRTIO_GPIO_F_IRQ, 647 }; 648 649 static struct virtio_driver virtio_gpio_driver = { 650 .feature_table = features, 651 .feature_table_size = ARRAY_SIZE(features), 652 .id_table = id_table, 653 .probe = virtio_gpio_probe, 654 .remove = virtio_gpio_remove, 655 .driver = { 656 .name = KBUILD_MODNAME, 657 }, 658 }; 659 module_virtio_driver(virtio_gpio_driver); 660 661 MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>"); 662 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 663 MODULE_DESCRIPTION("VirtIO GPIO driver"); 664 MODULE_LICENSE("GPL"); 665