1 /* 2 * I2C Link Layer for ST21NFCA HCI based Driver 3 * Copyright (C) 2014 STMicroelectronics SAS. All rights reserved. 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms and conditions of the GNU General Public License, 7 * version 2, as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 19 20 #include <linux/crc-ccitt.h> 21 #include <linux/module.h> 22 #include <linux/i2c.h> 23 #include <linux/gpio/consumer.h> 24 #include <linux/of_irq.h> 25 #include <linux/of_gpio.h> 26 #include <linux/acpi.h> 27 #include <linux/interrupt.h> 28 #include <linux/delay.h> 29 #include <linux/nfc.h> 30 #include <linux/firmware.h> 31 32 #include <asm/unaligned.h> 33 34 #include <net/nfc/hci.h> 35 #include <net/nfc/llc.h> 36 #include <net/nfc/nfc.h> 37 38 #include "st21nfca.h" 39 40 /* 41 * Every frame starts with ST21NFCA_SOF_EOF and ends with ST21NFCA_SOF_EOF. 42 * Because ST21NFCA_SOF_EOF is a possible data value, there is a mecanism 43 * called byte stuffing has been introduced. 44 * 45 * if byte == ST21NFCA_SOF_EOF or ST21NFCA_ESCAPE_BYTE_STUFFING 46 * - insert ST21NFCA_ESCAPE_BYTE_STUFFING (escape byte) 47 * - xor byte with ST21NFCA_BYTE_STUFFING_MASK 48 */ 49 #define ST21NFCA_SOF_EOF 0x7e 50 #define ST21NFCA_BYTE_STUFFING_MASK 0x20 51 #define ST21NFCA_ESCAPE_BYTE_STUFFING 0x7d 52 53 /* SOF + 00 */ 54 #define ST21NFCA_FRAME_HEADROOM 2 55 56 /* 2 bytes crc + EOF */ 57 #define ST21NFCA_FRAME_TAILROOM 3 58 #define IS_START_OF_FRAME(buf) (buf[0] == ST21NFCA_SOF_EOF && \ 59 buf[1] == 0) 60 61 #define ST21NFCA_HCI_DRIVER_NAME "st21nfca_hci" 62 #define ST21NFCA_HCI_I2C_DRIVER_NAME "st21nfca_hci_i2c" 63 64 #define ST21NFCA_GPIO_NAME_EN "enable" 65 66 struct st21nfca_i2c_phy { 67 struct i2c_client *i2c_dev; 68 struct nfc_hci_dev *hdev; 69 70 struct gpio_desc *gpiod_ena; 71 struct st21nfca_se_status se_status; 72 73 struct sk_buff *pending_skb; 74 int current_read_len; 75 /* 76 * crc might have fail because i2c macro 77 * is disable due to other interface activity 78 */ 79 int crc_trials; 80 81 int powered; 82 int run_mode; 83 84 /* 85 * < 0 if hardware error occured (e.g. i2c err) 86 * and prevents normal operation. 87 */ 88 int hard_fault; 89 struct mutex phy_lock; 90 }; 91 92 static u8 len_seq[] = { 16, 24, 12, 29 }; 93 static u16 wait_tab[] = { 2, 3, 5, 15, 20, 40}; 94 95 #define I2C_DUMP_SKB(info, skb) \ 96 do { \ 97 pr_debug("%s:\n", info); \ 98 print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \ 99 16, 1, (skb)->data, (skb)->len, 0); \ 100 } while (0) 101 102 /* 103 * In order to get the CLF in a known state we generate an internal reboot 104 * using a proprietary command. 105 * Once the reboot is completed, we expect to receive a ST21NFCA_SOF_EOF 106 * fill buffer. 107 */ 108 static int st21nfca_hci_platform_init(struct st21nfca_i2c_phy *phy) 109 { 110 u16 wait_reboot[] = { 50, 300, 1000 }; 111 char reboot_cmd[] = { 0x7E, 0x66, 0x48, 0xF6, 0x7E }; 112 u8 tmp[ST21NFCA_HCI_LLC_MAX_SIZE]; 113 int i, r = -1; 114 115 for (i = 0; i < ARRAY_SIZE(wait_reboot) && r < 0; i++) { 116 r = i2c_master_send(phy->i2c_dev, reboot_cmd, 117 sizeof(reboot_cmd)); 118 if (r < 0) 119 msleep(wait_reboot[i]); 120 } 121 if (r < 0) 122 return r; 123 124 /* CLF is spending about 20ms to do an internal reboot */ 125 msleep(20); 126 r = -1; 127 for (i = 0; i < ARRAY_SIZE(wait_reboot) && r < 0; i++) { 128 r = i2c_master_recv(phy->i2c_dev, tmp, 129 ST21NFCA_HCI_LLC_MAX_SIZE); 130 if (r < 0) 131 msleep(wait_reboot[i]); 132 } 133 if (r < 0) 134 return r; 135 136 for (i = 0; i < ST21NFCA_HCI_LLC_MAX_SIZE && 137 tmp[i] == ST21NFCA_SOF_EOF; i++) 138 ; 139 140 if (r != ST21NFCA_HCI_LLC_MAX_SIZE) 141 return -ENODEV; 142 143 usleep_range(1000, 1500); 144 return 0; 145 } 146 147 static int st21nfca_hci_i2c_enable(void *phy_id) 148 { 149 struct st21nfca_i2c_phy *phy = phy_id; 150 151 gpiod_set_value(phy->gpiod_ena, 1); 152 phy->powered = 1; 153 phy->run_mode = ST21NFCA_HCI_MODE; 154 155 usleep_range(10000, 15000); 156 157 return 0; 158 } 159 160 static void st21nfca_hci_i2c_disable(void *phy_id) 161 { 162 struct st21nfca_i2c_phy *phy = phy_id; 163 164 gpiod_set_value(phy->gpiod_ena, 0); 165 166 phy->powered = 0; 167 } 168 169 static void st21nfca_hci_add_len_crc(struct sk_buff *skb) 170 { 171 u16 crc; 172 u8 tmp; 173 174 *skb_push(skb, 1) = 0; 175 176 crc = crc_ccitt(0xffff, skb->data, skb->len); 177 crc = ~crc; 178 179 tmp = crc & 0x00ff; 180 *skb_put(skb, 1) = tmp; 181 182 tmp = (crc >> 8) & 0x00ff; 183 *skb_put(skb, 1) = tmp; 184 } 185 186 static void st21nfca_hci_remove_len_crc(struct sk_buff *skb) 187 { 188 skb_pull(skb, ST21NFCA_FRAME_HEADROOM); 189 skb_trim(skb, skb->len - ST21NFCA_FRAME_TAILROOM); 190 } 191 192 /* 193 * Writing a frame must not return the number of written bytes. 194 * It must return either zero for success, or <0 for error. 195 * In addition, it must not alter the skb 196 */ 197 static int st21nfca_hci_i2c_write(void *phy_id, struct sk_buff *skb) 198 { 199 int r = -1, i, j; 200 struct st21nfca_i2c_phy *phy = phy_id; 201 struct i2c_client *client = phy->i2c_dev; 202 u8 tmp[ST21NFCA_HCI_LLC_MAX_SIZE * 2]; 203 204 I2C_DUMP_SKB("st21nfca_hci_i2c_write", skb); 205 206 if (phy->hard_fault != 0) 207 return phy->hard_fault; 208 209 /* 210 * Compute CRC before byte stuffing computation on frame 211 * Note st21nfca_hci_add_len_crc is doing a byte stuffing 212 * on its own value 213 */ 214 st21nfca_hci_add_len_crc(skb); 215 216 /* add ST21NFCA_SOF_EOF on tail */ 217 *skb_put(skb, 1) = ST21NFCA_SOF_EOF; 218 /* add ST21NFCA_SOF_EOF on head */ 219 *skb_push(skb, 1) = ST21NFCA_SOF_EOF; 220 221 /* 222 * Compute byte stuffing 223 * if byte == ST21NFCA_SOF_EOF or ST21NFCA_ESCAPE_BYTE_STUFFING 224 * insert ST21NFCA_ESCAPE_BYTE_STUFFING (escape byte) 225 * xor byte with ST21NFCA_BYTE_STUFFING_MASK 226 */ 227 tmp[0] = skb->data[0]; 228 for (i = 1, j = 1; i < skb->len - 1; i++, j++) { 229 if (skb->data[i] == ST21NFCA_SOF_EOF 230 || skb->data[i] == ST21NFCA_ESCAPE_BYTE_STUFFING) { 231 tmp[j] = ST21NFCA_ESCAPE_BYTE_STUFFING; 232 j++; 233 tmp[j] = skb->data[i] ^ ST21NFCA_BYTE_STUFFING_MASK; 234 } else { 235 tmp[j] = skb->data[i]; 236 } 237 } 238 tmp[j] = skb->data[i]; 239 j++; 240 241 /* 242 * Manage sleep mode 243 * Try 3 times to send data with delay between each 244 */ 245 mutex_lock(&phy->phy_lock); 246 for (i = 0; i < ARRAY_SIZE(wait_tab) && r < 0; i++) { 247 r = i2c_master_send(client, tmp, j); 248 if (r < 0) 249 msleep(wait_tab[i]); 250 } 251 mutex_unlock(&phy->phy_lock); 252 253 if (r >= 0) { 254 if (r != j) 255 r = -EREMOTEIO; 256 else 257 r = 0; 258 } 259 260 st21nfca_hci_remove_len_crc(skb); 261 262 return r; 263 } 264 265 static int get_frame_size(u8 *buf, int buflen) 266 { 267 int len = 0; 268 269 if (buf[len + 1] == ST21NFCA_SOF_EOF) 270 return 0; 271 272 for (len = 1; len < buflen && buf[len] != ST21NFCA_SOF_EOF; len++) 273 ; 274 275 return len; 276 } 277 278 static int check_crc(u8 *buf, int buflen) 279 { 280 u16 crc; 281 282 crc = crc_ccitt(0xffff, buf, buflen - 2); 283 crc = ~crc; 284 285 if (buf[buflen - 2] != (crc & 0xff) || buf[buflen - 1] != (crc >> 8)) { 286 pr_err(ST21NFCA_HCI_DRIVER_NAME 287 ": CRC error 0x%x != 0x%x 0x%x\n", crc, buf[buflen - 1], 288 buf[buflen - 2]); 289 290 pr_info(DRIVER_DESC ": %s : BAD CRC\n", __func__); 291 print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE, 292 16, 2, buf, buflen, false); 293 return -EPERM; 294 } 295 return 0; 296 } 297 298 /* 299 * Prepare received data for upper layer. 300 * Received data include byte stuffing, crc and sof/eof 301 * which is not usable by hci part. 302 * returns: 303 * frame size without sof/eof, header and byte stuffing 304 * -EBADMSG : frame was incorrect and discarded 305 */ 306 static int st21nfca_hci_i2c_repack(struct sk_buff *skb) 307 { 308 int i, j, r, size; 309 310 if (skb->len < 1 || (skb->len > 1 && skb->data[1] != 0)) 311 return -EBADMSG; 312 313 size = get_frame_size(skb->data, skb->len); 314 if (size > 0) { 315 skb_trim(skb, size); 316 /* remove ST21NFCA byte stuffing for upper layer */ 317 for (i = 1, j = 0; i < skb->len; i++) { 318 if (skb->data[i + j] == 319 (u8) ST21NFCA_ESCAPE_BYTE_STUFFING) { 320 skb->data[i] = skb->data[i + j + 1] 321 | ST21NFCA_BYTE_STUFFING_MASK; 322 i++; 323 j++; 324 } 325 skb->data[i] = skb->data[i + j]; 326 } 327 /* remove byte stuffing useless byte */ 328 skb_trim(skb, i - j); 329 /* remove ST21NFCA_SOF_EOF from head */ 330 skb_pull(skb, 1); 331 332 r = check_crc(skb->data, skb->len); 333 if (r != 0) { 334 i = 0; 335 return -EBADMSG; 336 } 337 338 /* remove headbyte */ 339 skb_pull(skb, 1); 340 /* remove crc. Byte Stuffing is already removed here */ 341 skb_trim(skb, skb->len - 2); 342 return skb->len; 343 } 344 return 0; 345 } 346 347 /* 348 * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees 349 * that i2c bus will be flushed and that next read will start on a new frame. 350 * returned skb contains only LLC header and payload. 351 * returns: 352 * frame size : if received frame is complete (find ST21NFCA_SOF_EOF at 353 * end of read) 354 * -EAGAIN : if received frame is incomplete (not find ST21NFCA_SOF_EOF 355 * at end of read) 356 * -EREMOTEIO : i2c read error (fatal) 357 * -EBADMSG : frame was incorrect and discarded 358 * (value returned from st21nfca_hci_i2c_repack) 359 * -EIO : if no ST21NFCA_SOF_EOF is found after reaching 360 * the read length end sequence 361 */ 362 static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy, 363 struct sk_buff *skb) 364 { 365 int r, i; 366 u8 len; 367 u8 buf[ST21NFCA_HCI_LLC_MAX_PAYLOAD]; 368 struct i2c_client *client = phy->i2c_dev; 369 370 if (phy->current_read_len < ARRAY_SIZE(len_seq)) { 371 len = len_seq[phy->current_read_len]; 372 373 /* 374 * Add retry mecanism 375 * Operation on I2C interface may fail in case of operation on 376 * RF or SWP interface 377 */ 378 r = 0; 379 mutex_lock(&phy->phy_lock); 380 for (i = 0; i < ARRAY_SIZE(wait_tab) && r <= 0; i++) { 381 r = i2c_master_recv(client, buf, len); 382 if (r < 0) 383 msleep(wait_tab[i]); 384 } 385 mutex_unlock(&phy->phy_lock); 386 387 if (r != len) { 388 phy->current_read_len = 0; 389 return -EREMOTEIO; 390 } 391 392 /* 393 * The first read sequence does not start with SOF. 394 * Data is corrupeted so we drop it. 395 */ 396 if (!phy->current_read_len && !IS_START_OF_FRAME(buf)) { 397 skb_trim(skb, 0); 398 phy->current_read_len = 0; 399 return -EIO; 400 } else if (phy->current_read_len && IS_START_OF_FRAME(buf)) { 401 /* 402 * Previous frame transmission was interrupted and 403 * the frame got repeated. 404 * Received frame start with ST21NFCA_SOF_EOF + 00. 405 */ 406 skb_trim(skb, 0); 407 phy->current_read_len = 0; 408 } 409 410 memcpy(skb_put(skb, len), buf, len); 411 412 if (skb->data[skb->len - 1] == ST21NFCA_SOF_EOF) { 413 phy->current_read_len = 0; 414 return st21nfca_hci_i2c_repack(skb); 415 } 416 phy->current_read_len++; 417 return -EAGAIN; 418 } 419 return -EIO; 420 } 421 422 /* 423 * Reads an shdlc frame from the chip. This is not as straightforward as it 424 * seems. The frame format is data-crc, and corruption can occur anywhere 425 * while transiting on i2c bus, such that we could read an invalid data. 426 * The tricky case is when we read a corrupted data or crc. We must detect 427 * this here in order to determine that data can be transmitted to the hci 428 * core. This is the reason why we check the crc here. 429 * The CLF will repeat a frame until we send a RR on that frame. 430 * 431 * On ST21NFCA, IRQ goes in idle when read starts. As no size information are 432 * available in the incoming data, other IRQ might come. Every IRQ will trigger 433 * a read sequence with different length and will fill the current frame. 434 * The reception is complete once we reach a ST21NFCA_SOF_EOF. 435 */ 436 static irqreturn_t st21nfca_hci_irq_thread_fn(int irq, void *phy_id) 437 { 438 struct st21nfca_i2c_phy *phy = phy_id; 439 struct i2c_client *client; 440 441 int r; 442 443 if (!phy || irq != phy->i2c_dev->irq) { 444 WARN_ON_ONCE(1); 445 return IRQ_NONE; 446 } 447 448 client = phy->i2c_dev; 449 dev_dbg(&client->dev, "IRQ\n"); 450 451 if (phy->hard_fault != 0) 452 return IRQ_HANDLED; 453 454 r = st21nfca_hci_i2c_read(phy, phy->pending_skb); 455 if (r == -EREMOTEIO) { 456 phy->hard_fault = r; 457 458 nfc_hci_recv_frame(phy->hdev, NULL); 459 460 return IRQ_HANDLED; 461 } else if (r == -EAGAIN || r == -EIO) { 462 return IRQ_HANDLED; 463 } else if (r == -EBADMSG && phy->crc_trials < ARRAY_SIZE(wait_tab)) { 464 /* 465 * With ST21NFCA, only one interface (I2C, RF or SWP) 466 * may be active at a time. 467 * Having incorrect crc is usually due to i2c macrocell 468 * deactivation in the middle of a transmission. 469 * It may generate corrupted data on i2c. 470 * We give sometime to get i2c back. 471 * The complete frame will be repeated. 472 */ 473 msleep(wait_tab[phy->crc_trials]); 474 phy->crc_trials++; 475 phy->current_read_len = 0; 476 kfree_skb(phy->pending_skb); 477 } else if (r > 0) { 478 /* 479 * We succeeded to read data from the CLF and 480 * data is valid. 481 * Reset counter. 482 */ 483 nfc_hci_recv_frame(phy->hdev, phy->pending_skb); 484 phy->crc_trials = 0; 485 } else { 486 kfree_skb(phy->pending_skb); 487 } 488 489 phy->pending_skb = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE * 2, GFP_KERNEL); 490 if (phy->pending_skb == NULL) { 491 phy->hard_fault = -ENOMEM; 492 nfc_hci_recv_frame(phy->hdev, NULL); 493 } 494 495 return IRQ_HANDLED; 496 } 497 498 static struct nfc_phy_ops i2c_phy_ops = { 499 .write = st21nfca_hci_i2c_write, 500 .enable = st21nfca_hci_i2c_enable, 501 .disable = st21nfca_hci_i2c_disable, 502 }; 503 504 static int st21nfca_hci_i2c_acpi_request_resources(struct i2c_client *client) 505 { 506 struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client); 507 struct device *dev = &client->dev; 508 509 /* Get EN GPIO from ACPI */ 510 phy->gpiod_ena = devm_gpiod_get_index(dev, ST21NFCA_GPIO_NAME_EN, 1, 511 GPIOD_OUT_LOW); 512 if (IS_ERR(phy->gpiod_ena)) { 513 nfc_err(dev, "Unable to get ENABLE GPIO\n"); 514 return PTR_ERR(phy->gpiod_ena); 515 } 516 517 return 0; 518 } 519 520 static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client) 521 { 522 struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client); 523 struct device *dev = &client->dev; 524 525 /* Get GPIO from device tree */ 526 phy->gpiod_ena = devm_gpiod_get_index(dev, ST21NFCA_GPIO_NAME_EN, 0, 527 GPIOD_OUT_HIGH); 528 if (IS_ERR(phy->gpiod_ena)) { 529 nfc_err(dev, "Failed to request enable pin\n"); 530 return PTR_ERR(phy->gpiod_ena); 531 } 532 533 return 0; 534 } 535 536 static int st21nfca_hci_i2c_probe(struct i2c_client *client, 537 const struct i2c_device_id *id) 538 { 539 struct st21nfca_i2c_phy *phy; 540 int r; 541 542 dev_dbg(&client->dev, "%s\n", __func__); 543 dev_dbg(&client->dev, "IRQ: %d\n", client->irq); 544 545 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 546 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 547 return -ENODEV; 548 } 549 550 phy = devm_kzalloc(&client->dev, sizeof(struct st21nfca_i2c_phy), 551 GFP_KERNEL); 552 if (!phy) 553 return -ENOMEM; 554 555 phy->i2c_dev = client; 556 phy->pending_skb = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE * 2, GFP_KERNEL); 557 if (phy->pending_skb == NULL) 558 return -ENOMEM; 559 560 phy->current_read_len = 0; 561 phy->crc_trials = 0; 562 mutex_init(&phy->phy_lock); 563 i2c_set_clientdata(client, phy); 564 565 if (client->dev.of_node) { 566 r = st21nfca_hci_i2c_of_request_resources(client); 567 if (r) { 568 nfc_err(&client->dev, "No platform data\n"); 569 return r; 570 } 571 } else if (ACPI_HANDLE(&client->dev)) { 572 r = st21nfca_hci_i2c_acpi_request_resources(client); 573 if (r) { 574 nfc_err(&client->dev, "Cannot get ACPI data\n"); 575 return r; 576 } 577 } else { 578 nfc_err(&client->dev, "st21nfca platform resources not available\n"); 579 return -ENODEV; 580 } 581 582 phy->se_status.is_ese_present = 583 device_property_read_bool(&client->dev, "ese-present"); 584 phy->se_status.is_uicc_present = 585 device_property_read_bool(&client->dev, "uicc-present"); 586 587 r = st21nfca_hci_platform_init(phy); 588 if (r < 0) { 589 nfc_err(&client->dev, "Unable to reboot st21nfca\n"); 590 return r; 591 } 592 593 r = devm_request_threaded_irq(&client->dev, client->irq, NULL, 594 st21nfca_hci_irq_thread_fn, 595 IRQF_ONESHOT, 596 ST21NFCA_HCI_DRIVER_NAME, phy); 597 if (r < 0) { 598 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 599 return r; 600 } 601 602 return st21nfca_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME, 603 ST21NFCA_FRAME_HEADROOM, 604 ST21NFCA_FRAME_TAILROOM, 605 ST21NFCA_HCI_LLC_MAX_PAYLOAD, 606 &phy->hdev, 607 &phy->se_status); 608 } 609 610 static int st21nfca_hci_i2c_remove(struct i2c_client *client) 611 { 612 struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client); 613 614 dev_dbg(&client->dev, "%s\n", __func__); 615 616 st21nfca_hci_remove(phy->hdev); 617 618 if (phy->powered) 619 st21nfca_hci_i2c_disable(phy); 620 621 return 0; 622 } 623 624 static struct i2c_device_id st21nfca_hci_i2c_id_table[] = { 625 {ST21NFCA_HCI_DRIVER_NAME, 0}, 626 {} 627 }; 628 MODULE_DEVICE_TABLE(i2c, st21nfca_hci_i2c_id_table); 629 630 static const struct acpi_device_id st21nfca_hci_i2c_acpi_match[] = { 631 {"SMO2100", 0}, 632 {} 633 }; 634 MODULE_DEVICE_TABLE(acpi, st21nfca_hci_i2c_acpi_match); 635 636 static const struct of_device_id of_st21nfca_i2c_match[] = { 637 { .compatible = "st,st21nfca-i2c", }, 638 { .compatible = "st,st21nfca_i2c", }, 639 {} 640 }; 641 MODULE_DEVICE_TABLE(of, of_st21nfca_i2c_match); 642 643 static struct i2c_driver st21nfca_hci_i2c_driver = { 644 .driver = { 645 .name = ST21NFCA_HCI_I2C_DRIVER_NAME, 646 .of_match_table = of_match_ptr(of_st21nfca_i2c_match), 647 .acpi_match_table = ACPI_PTR(st21nfca_hci_i2c_acpi_match), 648 }, 649 .probe = st21nfca_hci_i2c_probe, 650 .id_table = st21nfca_hci_i2c_id_table, 651 .remove = st21nfca_hci_i2c_remove, 652 }; 653 module_i2c_driver(st21nfca_hci_i2c_driver); 654 655 MODULE_LICENSE("GPL"); 656 MODULE_DESCRIPTION(DRIVER_DESC); 657