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 24struct 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 32struct 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 44struct 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 58static 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 121out: 122 mutex_unlock(&line->lock); 123 return ret; 124} 125 126static 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 136static 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 144static 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 165static 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 173static 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 187static 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 197static 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 */ 205static 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 232static 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 247static 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 262static 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 273static 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 287static 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 320static 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 328static 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 353static struct irq_chip vgpio_irq_chip = { 354 .name = "virtio-gpio", 355 .irq_enable = virtio_gpio_irq_enable, 356 .irq_disable = virtio_gpio_irq_disable, 357 .irq_mask = virtio_gpio_irq_mask, 358 .irq_unmask = virtio_gpio_irq_unmask, 359 .irq_set_type = virtio_gpio_irq_set_type, 360 361 /* These are required to implement irqchip for slow busses */ 362 .irq_bus_lock = virtio_gpio_irq_bus_lock, 363 .irq_bus_sync_unlock = virtio_gpio_irq_bus_sync_unlock, 364}; 365 366static bool ignore_irq(struct virtio_gpio *vgpio, int gpio, 367 struct vgpio_irq_line *irq_line) 368{ 369 bool ignore = false; 370 371 raw_spin_lock(&vgpio->eventq_lock); 372 irq_line->queued = false; 373 374 /* Interrupt is disabled currently */ 375 if (irq_line->masked || irq_line->disabled) { 376 ignore = true; 377 goto unlock; 378 } 379 380 /* 381 * Buffer is returned as the interrupt was disabled earlier, but is 382 * enabled again now. Requeue the buffers. 383 */ 384 if (irq_line->ires.status == VIRTIO_GPIO_IRQ_STATUS_INVALID) { 385 virtio_gpio_irq_prepare(vgpio, gpio); 386 ignore = true; 387 goto unlock; 388 } 389 390 if (WARN_ON(irq_line->ires.status != VIRTIO_GPIO_IRQ_STATUS_VALID)) 391 ignore = true; 392 393unlock: 394 raw_spin_unlock(&vgpio->eventq_lock); 395 396 return ignore; 397} 398 399static void virtio_gpio_event_vq(struct virtqueue *vq) 400{ 401 struct virtio_gpio *vgpio = vq->vdev->priv; 402 struct device *dev = &vgpio->vdev->dev; 403 struct vgpio_irq_line *irq_line; 404 int gpio, ret; 405 unsigned int len; 406 407 while (true) { 408 irq_line = virtqueue_get_buf(vgpio->event_vq, &len); 409 if (!irq_line) 410 break; 411 412 if (len != sizeof(irq_line->ires)) { 413 dev_err(dev, "irq with incorrect length (%u : %u)\n", 414 len, (unsigned int)sizeof(irq_line->ires)); 415 continue; 416 } 417 418 /* 419 * Find GPIO line number from the offset of irq_line within the 420 * irq_lines block. We can also get GPIO number from 421 * irq-request, but better not to rely on a buffer returned by 422 * remote. 423 */ 424 gpio = irq_line - vgpio->irq_lines; 425 WARN_ON(gpio >= vgpio->gc.ngpio); 426 427 if (unlikely(ignore_irq(vgpio, gpio, irq_line))) 428 continue; 429 430 ret = generic_handle_domain_irq(vgpio->gc.irq.domain, gpio); 431 if (ret) 432 dev_err(dev, "failed to handle interrupt: %d\n", ret); 433 } 434} 435 436static void virtio_gpio_request_vq(struct virtqueue *vq) 437{ 438 struct virtio_gpio_line *line; 439 unsigned int len; 440 441 do { 442 line = virtqueue_get_buf(vq, &len); 443 if (!line) 444 return; 445 446 line->rxlen = len; 447 complete(&line->completion); 448 } while (1); 449} 450 451static void virtio_gpio_free_vqs(struct virtio_device *vdev) 452{ 453 virtio_reset_device(vdev); 454 vdev->config->del_vqs(vdev); 455} 456 457static int virtio_gpio_alloc_vqs(struct virtio_gpio *vgpio, 458 struct virtio_device *vdev) 459{ 460 const char * const names[] = { "requestq", "eventq" }; 461 vq_callback_t *cbs[] = { 462 virtio_gpio_request_vq, 463 virtio_gpio_event_vq, 464 }; 465 struct virtqueue *vqs[2] = { NULL, NULL }; 466 int ret; 467 468 ret = virtio_find_vqs(vdev, vgpio->irq_lines ? 2 : 1, vqs, cbs, names, NULL); 469 if (ret) { 470 dev_err(&vdev->dev, "failed to find vqs: %d\n", ret); 471 return ret; 472 } 473 474 if (!vqs[0]) { 475 dev_err(&vdev->dev, "failed to find requestq vq\n"); 476 goto out; 477 } 478 vgpio->request_vq = vqs[0]; 479 480 if (vgpio->irq_lines && !vqs[1]) { 481 dev_err(&vdev->dev, "failed to find eventq vq\n"); 482 goto out; 483 } 484 vgpio->event_vq = vqs[1]; 485 486 return 0; 487 488out: 489 if (vqs[0] || vqs[1]) 490 virtio_gpio_free_vqs(vdev); 491 492 return -ENODEV; 493} 494 495static const char **virtio_gpio_get_names(struct virtio_gpio *vgpio, 496 u32 gpio_names_size, u16 ngpio) 497{ 498 struct virtio_gpio_response_get_names *res; 499 struct device *dev = &vgpio->vdev->dev; 500 u8 *gpio_names, *str; 501 const char **names; 502 int i, ret, len; 503 504 if (!gpio_names_size) 505 return NULL; 506 507 len = sizeof(*res) + gpio_names_size; 508 res = devm_kzalloc(dev, len, GFP_KERNEL); 509 if (!res) 510 return NULL; 511 gpio_names = res->value; 512 513 ret = _virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_NAMES, 0, 0, NULL, 514 res, len); 515 if (ret) { 516 dev_err(dev, "Failed to get GPIO names: %d\n", ret); 517 return NULL; 518 } 519 520 names = devm_kcalloc(dev, ngpio, sizeof(*names), GFP_KERNEL); 521 if (!names) 522 return NULL; 523 524 /* NULL terminate the string instead of checking it */ 525 gpio_names[gpio_names_size - 1] = '\0'; 526 527 for (i = 0, str = gpio_names; i < ngpio; i++) { 528 names[i] = str; 529 str += strlen(str) + 1; /* zero-length strings are allowed */ 530 531 if (str > gpio_names + gpio_names_size) { 532 dev_err(dev, "gpio_names block is too short (%d)\n", i); 533 return NULL; 534 } 535 } 536 537 return names; 538} 539 540static int virtio_gpio_probe(struct virtio_device *vdev) 541{ 542 struct virtio_gpio_config config; 543 struct device *dev = &vdev->dev; 544 struct virtio_gpio *vgpio; 545 u32 gpio_names_size; 546 u16 ngpio; 547 int ret, i; 548 549 vgpio = devm_kzalloc(dev, sizeof(*vgpio), GFP_KERNEL); 550 if (!vgpio) 551 return -ENOMEM; 552 553 /* Read configuration */ 554 virtio_cread_bytes(vdev, 0, &config, sizeof(config)); 555 gpio_names_size = le32_to_cpu(config.gpio_names_size); 556 ngpio = le16_to_cpu(config.ngpio); 557 if (!ngpio) { 558 dev_err(dev, "Number of GPIOs can't be zero\n"); 559 return -EINVAL; 560 } 561 562 vgpio->lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->lines), GFP_KERNEL); 563 if (!vgpio->lines) 564 return -ENOMEM; 565 566 for (i = 0; i < ngpio; i++) { 567 mutex_init(&vgpio->lines[i].lock); 568 init_completion(&vgpio->lines[i].completion); 569 } 570 571 mutex_init(&vgpio->lock); 572 vdev->priv = vgpio; 573 574 vgpio->vdev = vdev; 575 vgpio->gc.free = virtio_gpio_free; 576 vgpio->gc.get_direction = virtio_gpio_get_direction; 577 vgpio->gc.direction_input = virtio_gpio_direction_input; 578 vgpio->gc.direction_output = virtio_gpio_direction_output; 579 vgpio->gc.get = virtio_gpio_get; 580 vgpio->gc.set = virtio_gpio_set; 581 vgpio->gc.ngpio = ngpio; 582 vgpio->gc.base = -1; /* Allocate base dynamically */ 583 vgpio->gc.label = dev_name(dev); 584 vgpio->gc.parent = dev; 585 vgpio->gc.owner = THIS_MODULE; 586 vgpio->gc.can_sleep = true; 587 588 /* Interrupt support */ 589 if (virtio_has_feature(vdev, VIRTIO_GPIO_F_IRQ)) { 590 vgpio->irq_lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->irq_lines), GFP_KERNEL); 591 if (!vgpio->irq_lines) 592 return -ENOMEM; 593 594 /* The event comes from the outside so no parent handler */ 595 vgpio->gc.irq.parent_handler = NULL; 596 vgpio->gc.irq.num_parents = 0; 597 vgpio->gc.irq.parents = NULL; 598 vgpio->gc.irq.default_type = IRQ_TYPE_NONE; 599 vgpio->gc.irq.handler = handle_level_irq; 600 vgpio->gc.irq.chip = &vgpio_irq_chip; 601 602 for (i = 0; i < ngpio; i++) { 603 vgpio->irq_lines[i].type = VIRTIO_GPIO_IRQ_TYPE_NONE; 604 vgpio->irq_lines[i].disabled = true; 605 vgpio->irq_lines[i].masked = true; 606 } 607 608 mutex_init(&vgpio->irq_lock); 609 raw_spin_lock_init(&vgpio->eventq_lock); 610 } 611 612 ret = virtio_gpio_alloc_vqs(vgpio, vdev); 613 if (ret) 614 return ret; 615 616 /* Mark the device ready to perform operations from within probe() */ 617 virtio_device_ready(vdev); 618 619 vgpio->gc.names = virtio_gpio_get_names(vgpio, gpio_names_size, ngpio); 620 621 ret = gpiochip_add_data(&vgpio->gc, vgpio); 622 if (ret) { 623 virtio_gpio_free_vqs(vdev); 624 dev_err(dev, "Failed to add virtio-gpio controller\n"); 625 } 626 627 return ret; 628} 629 630static void virtio_gpio_remove(struct virtio_device *vdev) 631{ 632 struct virtio_gpio *vgpio = vdev->priv; 633 634 gpiochip_remove(&vgpio->gc); 635 virtio_gpio_free_vqs(vdev); 636} 637 638static const struct virtio_device_id id_table[] = { 639 { VIRTIO_ID_GPIO, VIRTIO_DEV_ANY_ID }, 640 {}, 641}; 642MODULE_DEVICE_TABLE(virtio, id_table); 643 644static const unsigned int features[] = { 645 VIRTIO_GPIO_F_IRQ, 646}; 647 648static struct virtio_driver virtio_gpio_driver = { 649 .feature_table = features, 650 .feature_table_size = ARRAY_SIZE(features), 651 .id_table = id_table, 652 .probe = virtio_gpio_probe, 653 .remove = virtio_gpio_remove, 654 .driver = { 655 .name = KBUILD_MODNAME, 656 .owner = THIS_MODULE, 657 }, 658}; 659module_virtio_driver(virtio_gpio_driver); 660 661MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>"); 662MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 663MODULE_DESCRIPTION("VirtIO GPIO driver"); 664MODULE_LICENSE("GPL"); 665