drivers/nfc/st21nfca/i2c.c

   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.h>
  24 #include <linux/of_irq.h>
  25 #include <linux/of_gpio.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/delay.h>
  29 #include <linux/nfc.h>
  30 #include <linux/firmware.h>
  31 #include <linux/platform_data/st21nfca.h>
  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_I2C_DRIVER_NAME "st21nfca_hci_i2c"
  62
  63 static struct i2c_device_id st21nfca_hci_i2c_id_table[] = {
  64         {ST21NFCA_HCI_DRIVER_NAME, 0},
  65         {}
  66 };
  67
  68 MODULE_DEVICE_TABLE(i2c, st21nfca_hci_i2c_id_table);
  69
  70 struct st21nfca_i2c_phy {
  71         struct i2c_client *i2c_dev;
  72         struct nfc_hci_dev *hdev;
  73
  74         unsigned int gpio_ena;
  75         unsigned int irq_polarity;
  76
  77         struct st21nfca_se_status se_status;
  78
  79         struct sk_buff *pending_skb;
  80         int current_read_len;
  81         /*
  82          * crc might have fail because i2c macro
  83          * is disable due to other interface activity
  84          */
  85         int crc_trials;
  86
  87         int powered;
  88         int run_mode;
  89
  90         /*
  91          * < 0 if hardware error occured (e.g. i2c err)
  92          * and prevents normal operation.
  93          */
  94         int hard_fault;
  95         struct mutex phy_lock;
  96 };
  97 static u8 len_seq[] = { 16, 24, 12, 29 };
  98 static u16 wait_tab[] = { 2, 3, 5, 15, 20, 40};
  99
 100 #define I2C_DUMP_SKB(info, skb)                                 \
 101 do {                                                            \
 102         pr_debug("%s:\n", info);                                \
 103         print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \
 104                        16, 1, (skb)->data, (skb)->len, 0);      \
 105 } while (0)
 106
 107 /*
 108  * In order to get the CLF in a known state we generate an internal reboot
 109  * using a proprietary command.
 110  * Once the reboot is completed, we expect to receive a ST21NFCA_SOF_EOF
 111  * fill buffer.
 112  */
 113 static int st21nfca_hci_platform_init(struct st21nfca_i2c_phy *phy)
 114 {
 115         u16 wait_reboot[] = { 50, 300, 1000 };
 116         char reboot_cmd[] = { 0x7E, 0x66, 0x48, 0xF6, 0x7E };
 117         u8 tmp[ST21NFCA_HCI_LLC_MAX_SIZE];
 118         int i, r = -1;
 119
 120         for (i = 0; i < ARRAY_SIZE(wait_reboot) && r < 0; i++) {
 121                 r = i2c_master_send(phy->i2c_dev, reboot_cmd,
 122                                     sizeof(reboot_cmd));
 123                 if (r < 0)
 124                         msleep(wait_reboot[i]);
 125         }
 126         if (r < 0)
 127                 return r;
 128
 129         /* CLF is spending about 20ms to do an internal reboot */
 130         msleep(20);
 131         r = -1;
 132         for (i = 0; i < ARRAY_SIZE(wait_reboot) && r < 0; i++) {
 133                 r = i2c_master_recv(phy->i2c_dev, tmp,
 134                                     ST21NFCA_HCI_LLC_MAX_SIZE);
 135                 if (r < 0)
 136                         msleep(wait_reboot[i]);
 137         }
 138         if (r < 0)
 139                 return r;
 140
 141         for (i = 0; i < ST21NFCA_HCI_LLC_MAX_SIZE &&
 142                 tmp[i] == ST21NFCA_SOF_EOF; i++)
 143                 ;
 144
 145         if (r != ST21NFCA_HCI_LLC_MAX_SIZE)
 146                 return -ENODEV;
 147
 148         usleep_range(1000, 1500);
 149         return 0;
 150 }
 151
 152 static int st21nfca_hci_i2c_enable(void *phy_id)
 153 {
 154         struct st21nfca_i2c_phy *phy = phy_id;
 155
 156         gpio_set_value(phy->gpio_ena, 1);
 157         phy->powered = 1;
 158         phy->run_mode = ST21NFCA_HCI_MODE;
 159
 160         usleep_range(10000, 15000);
 161
 162         return 0;
 163 }
 164
 165 static void st21nfca_hci_i2c_disable(void *phy_id)
 166 {
 167         struct st21nfca_i2c_phy *phy = phy_id;
 168
 169         pr_info("\n");
 170         gpio_set_value(phy->gpio_ena, 0);
 171
 172         phy->powered = 0;
 173 }
 174
 175 static void st21nfca_hci_add_len_crc(struct sk_buff *skb)
 176 {
 177         u16 crc;
 178         u8 tmp;
 179
 180         *skb_push(skb, 1) = 0;
 181
 182         crc = crc_ccitt(0xffff, skb->data, skb->len);
 183         crc = ~crc;
 184
 185         tmp = crc & 0x00ff;
 186         *skb_put(skb, 1) = tmp;
 187
 188         tmp = (crc >> 8) & 0x00ff;
 189         *skb_put(skb, 1) = tmp;
 190 }
 191
 192 static void st21nfca_hci_remove_len_crc(struct sk_buff *skb)
 193 {
 194         skb_pull(skb, ST21NFCA_FRAME_HEADROOM);
 195         skb_trim(skb, skb->len - ST21NFCA_FRAME_TAILROOM);
 196 }
 197
 198 /*
 199  * Writing a frame must not return the number of written bytes.
 200  * It must return either zero for success, or <0 for error.
 201  * In addition, it must not alter the skb
 202  */
 203 static int st21nfca_hci_i2c_write(void *phy_id, struct sk_buff *skb)
 204 {
 205         int r = -1, i, j;
 206         struct st21nfca_i2c_phy *phy = phy_id;
 207         struct i2c_client *client = phy->i2c_dev;
 208         u8 tmp[ST21NFCA_HCI_LLC_MAX_SIZE * 2];
 209
 210         I2C_DUMP_SKB("st21nfca_hci_i2c_write", skb);
 211
 212
 213         if (phy->hard_fault != 0)
 214                 return phy->hard_fault;
 215
 216         /*
 217          * Compute CRC before byte stuffing computation on frame
 218          * Note st21nfca_hci_add_len_crc is doing a byte stuffing
 219          * on its own value
 220          */
 221         st21nfca_hci_add_len_crc(skb);
 222
 223         /* add ST21NFCA_SOF_EOF on tail */
 224         *skb_put(skb, 1) = ST21NFCA_SOF_EOF;
 225         /* add ST21NFCA_SOF_EOF on head */
 226         *skb_push(skb, 1) = ST21NFCA_SOF_EOF;
 227
 228         /*
 229          * Compute byte stuffing
 230          * if byte == ST21NFCA_SOF_EOF or ST21NFCA_ESCAPE_BYTE_STUFFING
 231          * insert ST21NFCA_ESCAPE_BYTE_STUFFING (escape byte)
 232          * xor byte with ST21NFCA_BYTE_STUFFING_MASK
 233          */
 234         tmp[0] = skb->data[0];
 235         for (i = 1, j = 1; i < skb->len - 1; i++, j++) {
 236                 if (skb->data[i] == ST21NFCA_SOF_EOF
 237                     || skb->data[i] == ST21NFCA_ESCAPE_BYTE_STUFFING) {
 238                         tmp[j] = ST21NFCA_ESCAPE_BYTE_STUFFING;
 239                         j++;
 240                         tmp[j] = skb->data[i] ^ ST21NFCA_BYTE_STUFFING_MASK;
 241                 } else {
 242                         tmp[j] = skb->data[i];
 243                 }
 244         }
 245         tmp[j] = skb->data[i];
 246         j++;
 247
 248         /*
 249          * Manage sleep mode
 250          * Try 3 times to send data with delay between each
 251          */
 252         mutex_lock(&phy->phy_lock);
 253         for (i = 0; i < ARRAY_SIZE(wait_tab) && r < 0; i++) {
 254                 r = i2c_master_send(client, tmp, j);
 255                 if (r < 0)
 256                         msleep(wait_tab[i]);
 257         }
 258         mutex_unlock(&phy->phy_lock);
 259
 260         if (r >= 0) {
 261                 if (r != j)
 262                         r = -EREMOTEIO;
 263                 else
 264                         r = 0;
 265         }
 266
 267         st21nfca_hci_remove_len_crc(skb);
 268
 269         return r;
 270 }
 271
 272 static int get_frame_size(u8 *buf, int buflen)
 273 {
 274         int len = 0;
 275
 276         if (buf[len + 1] == ST21NFCA_SOF_EOF)
 277                 return 0;
 278
 279         for (len = 1; len < buflen && buf[len] != ST21NFCA_SOF_EOF; len++)
 280                 ;
 281
 282         return len;
 283 }
 284
 285 static int check_crc(u8 *buf, int buflen)
 286 {
 287         u16 crc;
 288
 289         crc = crc_ccitt(0xffff, buf, buflen - 2);
 290         crc = ~crc;
 291
 292         if (buf[buflen - 2] != (crc & 0xff) || buf[buflen - 1] != (crc >> 8)) {
 293                 pr_err(ST21NFCA_HCI_DRIVER_NAME
 294                        ": CRC error 0x%x != 0x%x 0x%x\n", crc, buf[buflen - 1],
 295                        buf[buflen - 2]);
 296
 297                 pr_info(DRIVER_DESC ": %s : BAD CRC\n", __func__);
 298                 print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
 299                                16, 2, buf, buflen, false);
 300                 return -EPERM;
 301         }
 302         return 0;
 303 }
 304
 305 /*
 306  * Prepare received data for upper layer.
 307  * Received data include byte stuffing, crc and sof/eof
 308  * which is not usable by hci part.
 309  * returns:
 310  * frame size without sof/eof, header and byte stuffing
 311  * -EBADMSG : frame was incorrect and discarded
 312  */
 313 static int st21nfca_hci_i2c_repack(struct sk_buff *skb)
 314 {
 315         int i, j, r, size;
 316
 317         if (skb->len < 1 || (skb->len > 1 && skb->data[1] != 0))
 318                 return -EBADMSG;
 319
 320         size = get_frame_size(skb->data, skb->len);
 321         if (size > 0) {
 322                 skb_trim(skb, size);
 323                 /* remove ST21NFCA byte stuffing for upper layer */
 324                 for (i = 1, j = 0; i < skb->len; i++) {
 325                         if (skb->data[i + j] ==
 326                                         (u8) ST21NFCA_ESCAPE_BYTE_STUFFING) {
 327                                 skb->data[i] = skb->data[i + j + 1]
 328                                                 | ST21NFCA_BYTE_STUFFING_MASK;
 329                                 i++;
 330                                 j++;
 331                         }
 332                         skb->data[i] = skb->data[i + j];
 333                 }
 334                 /* remove byte stuffing useless byte */
 335                 skb_trim(skb, i - j);
 336                 /* remove ST21NFCA_SOF_EOF from head */
 337                 skb_pull(skb, 1);
 338
 339                 r = check_crc(skb->data, skb->len);
 340                 if (r != 0) {
 341                         i = 0;
 342                         return -EBADMSG;
 343                 }
 344
 345                 /* remove headbyte */
 346                 skb_pull(skb, 1);
 347                 /* remove crc. Byte Stuffing is already removed here */
 348                 skb_trim(skb, skb->len - 2);
 349                 return skb->len;
 350         }
 351         return 0;
 352 }
 353
 354 /*
 355  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
 356  * that i2c bus will be flushed and that next read will start on a new frame.
 357  * returned skb contains only LLC header and payload.
 358  * returns:
 359  * frame size : if received frame is complete (find ST21NFCA_SOF_EOF at
 360  * end of read)
 361  * -EAGAIN : if received frame is incomplete (not find ST21NFCA_SOF_EOF
 362  * at end of read)
 363  * -EREMOTEIO : i2c read error (fatal)
 364  * -EBADMSG : frame was incorrect and discarded
 365  * (value returned from st21nfca_hci_i2c_repack)
 366  * -EIO : if no ST21NFCA_SOF_EOF is found after reaching
 367  * the read length end sequence
 368  */
 369 static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy,
 370                                  struct sk_buff *skb)
 371 {
 372         int r, i;
 373         u8 len;
 374         u8 buf[ST21NFCA_HCI_LLC_MAX_PAYLOAD];
 375         struct i2c_client *client = phy->i2c_dev;
 376
 377         if (phy->current_read_len < ARRAY_SIZE(len_seq)) {
 378                 len = len_seq[phy->current_read_len];
 379
 380                 /*
 381                  * Add retry mecanism
 382                  * Operation on I2C interface may fail in case of operation on
 383                  * RF or SWP interface
 384                  */
 385                 r = 0;
 386                 mutex_lock(&phy->phy_lock);
 387                 for (i = 0; i < ARRAY_SIZE(wait_tab) && r <= 0; i++) {
 388                         r = i2c_master_recv(client, buf, len);
 389                         if (r < 0)
 390                                 msleep(wait_tab[i]);
 391                 }
 392                 mutex_unlock(&phy->phy_lock);
 393
 394                 if (r != len) {
 395                         phy->current_read_len = 0;
 396                         return -EREMOTEIO;
 397                 }
 398
 399                 /*
 400                  * The first read sequence does not start with SOF.
 401                  * Data is corrupeted so we drop it.
 402                  */
 403                 if (!phy->current_read_len && !IS_START_OF_FRAME(buf)) {
 404                         skb_trim(skb, 0);
 405                         phy->current_read_len = 0;
 406                         return -EIO;
 407                 } else if (phy->current_read_len && IS_START_OF_FRAME(buf)) {
 408                         /*
 409                          * Previous frame transmission was interrupted and
 410                          * the frame got repeated.
 411                          * Received frame start with ST21NFCA_SOF_EOF + 00.
 412                          */
 413                         skb_trim(skb, 0);
 414                         phy->current_read_len = 0;
 415                 }
 416
 417                 memcpy(skb_put(skb, len), buf, len);
 418
 419                 if (skb->data[skb->len - 1] == ST21NFCA_SOF_EOF) {
 420                         phy->current_read_len = 0;
 421                         return st21nfca_hci_i2c_repack(skb);
 422                 }
 423                 phy->current_read_len++;
 424                 return -EAGAIN;
 425         }
 426         return -EIO;
 427 }
 428
 429 /*
 430  * Reads an shdlc frame from the chip. This is not as straightforward as it
 431  * seems. The frame format is data-crc, and corruption can occur anywhere
 432  * while transiting on i2c bus, such that we could read an invalid data.
 433  * The tricky case is when we read a corrupted data or crc. We must detect
 434  * this here in order to determine that data can be transmitted to the hci
 435  * core. This is the reason why we check the crc here.
 436  * The CLF will repeat a frame until we send a RR on that frame.
 437  *
 438  * On ST21NFCA, IRQ goes in idle when read starts. As no size information are
 439  * available in the incoming data, other IRQ might come. Every IRQ will trigger
 440  * a read sequence with different length and will fill the current frame.
 441  * The reception is complete once we reach a ST21NFCA_SOF_EOF.
 442  */
 443 static irqreturn_t st21nfca_hci_irq_thread_fn(int irq, void *phy_id)
 444 {
 445         struct st21nfca_i2c_phy *phy = phy_id;
 446         struct i2c_client *client;
 447
 448         int r;
 449
 450         if (!phy || irq != phy->i2c_dev->irq) {
 451                 WARN_ON_ONCE(1);
 452                 return IRQ_NONE;
 453         }
 454
 455         client = phy->i2c_dev;
 456         dev_dbg(&client->dev, "IRQ\n");
 457
 458         if (phy->hard_fault != 0)
 459                 return IRQ_HANDLED;
 460
 461         r = st21nfca_hci_i2c_read(phy, phy->pending_skb);
 462         if (r == -EREMOTEIO) {
 463                 phy->hard_fault = r;
 464
 465                 nfc_hci_recv_frame(phy->hdev, NULL);
 466
 467                 return IRQ_HANDLED;
 468         } else if (r == -EAGAIN || r == -EIO) {
 469                 return IRQ_HANDLED;
 470         } else if (r == -EBADMSG && phy->crc_trials < ARRAY_SIZE(wait_tab)) {
 471                 /*
 472                  * With ST21NFCA, only one interface (I2C, RF or SWP)
 473                  * may be active at a time.
 474                  * Having incorrect crc is usually due to i2c macrocell
 475                  * deactivation in the middle of a transmission.
 476                  * It may generate corrupted data on i2c.
 477                  * We give sometime to get i2c back.
 478                  * The complete frame will be repeated.
 479                  */
 480                 msleep(wait_tab[phy->crc_trials]);
 481                 phy->crc_trials++;
 482                 phy->current_read_len = 0;
 483                 kfree_skb(phy->pending_skb);
 484         } else if (r > 0) {
 485                 /*
 486                  * We succeeded to read data from the CLF and
 487                  * data is valid.
 488                  * Reset counter.
 489                  */
 490                 nfc_hci_recv_frame(phy->hdev, phy->pending_skb);
 491                 phy->crc_trials = 0;
 492         } else {
 493                 kfree_skb(phy->pending_skb);
 494         }
 495
 496         phy->pending_skb = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE * 2, GFP_KERNEL);
 497         if (phy->pending_skb == NULL) {
 498                 phy->hard_fault = -ENOMEM;
 499                 nfc_hci_recv_frame(phy->hdev, NULL);
 500         }
 501
 502         return IRQ_HANDLED;
 503 }
 504
 505 static struct nfc_phy_ops i2c_phy_ops = {
 506         .write = st21nfca_hci_i2c_write,
 507         .enable = st21nfca_hci_i2c_enable,
 508         .disable = st21nfca_hci_i2c_disable,
 509 };
 510
 511 #ifdef CONFIG_OF
 512 static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client)
 513 {
 514         struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 515         struct device_node *pp;
 516         int gpio;
 517         int r;
 518
 519         pp = client->dev.of_node;
 520         if (!pp)
 521                 return -ENODEV;
 522
 523         /* Get GPIO from device tree */
 524         gpio = of_get_named_gpio(pp, "enable-gpios", 0);
 525         if (gpio < 0) {
 526                 nfc_err(&client->dev, "Failed to retrieve enable-gpios from device tree\n");
 527                 return gpio;
 528         }
 529
 530         /* GPIO request and configuration */
 531         r = devm_gpio_request_one(&client->dev, gpio, GPIOF_OUT_INIT_HIGH,
 532                                   "clf_enable");
 533         if (r) {
 534                 nfc_err(&client->dev, "Failed to request enable pin\n");
 535                 return r;
 536         }
 537
 538         phy->gpio_ena = gpio;
 539
 540         phy->irq_polarity = irq_get_trigger_type(client->irq);
 541
 542         phy->se_status.is_ese_present =
 543                                 of_property_read_bool(pp, "ese-present");
 544         phy->se_status.is_uicc_present =
 545                                 of_property_read_bool(pp, "uicc-present");
 546
 547         return 0;
 548 }
 549 #else
 550 static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client)
 551 {
 552         return -ENODEV;
 553 }
 554 #endif
 555
 556 static int st21nfca_hci_i2c_request_resources(struct i2c_client *client)
 557 {
 558         struct st21nfca_nfc_platform_data *pdata;
 559         struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 560         int r;
 561
 562         pdata = client->dev.platform_data;
 563         if (pdata == NULL) {
 564                 nfc_err(&client->dev, "No platform data\n");
 565                 return -EINVAL;
 566         }
 567
 568         /* store for later use */
 569         phy->gpio_ena = pdata->gpio_ena;
 570         phy->irq_polarity = pdata->irq_polarity;
 571
 572         if (phy->gpio_ena > 0) {
 573                 r = devm_gpio_request_one(&client->dev, phy->gpio_ena,
 574                                           GPIOF_OUT_INIT_HIGH, "clf_enable");
 575                 if (r) {
 576                         pr_err("%s : ena gpio_request failed\n", __FILE__);
 577                         return r;
 578                 }
 579         }
 580
 581         phy->se_status.is_ese_present = pdata->is_ese_present;
 582         phy->se_status.is_uicc_present = pdata->is_uicc_present;
 583
 584         return 0;
 585 }
 586
 587 static int st21nfca_hci_i2c_probe(struct i2c_client *client,
 588                                   const struct i2c_device_id *id)
 589 {
 590         struct st21nfca_i2c_phy *phy;
 591         struct st21nfca_nfc_platform_data *pdata;
 592         int r;
 593
 594         dev_dbg(&client->dev, "%s\n", __func__);
 595         dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
 596
 597         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 598                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 599                 return -ENODEV;
 600         }
 601
 602         phy = devm_kzalloc(&client->dev, sizeof(struct st21nfca_i2c_phy),
 603                            GFP_KERNEL);
 604         if (!phy)
 605                 return -ENOMEM;
 606
 607         phy->i2c_dev = client;
 608         phy->pending_skb = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE * 2, GFP_KERNEL);
 609         if (phy->pending_skb == NULL)
 610                 return -ENOMEM;
 611
 612         phy->current_read_len = 0;
 613         phy->crc_trials = 0;
 614         mutex_init(&phy->phy_lock);
 615         i2c_set_clientdata(client, phy);
 616
 617         pdata = client->dev.platform_data;
 618         if (!pdata && client->dev.of_node) {
 619                 r = st21nfca_hci_i2c_of_request_resources(client);
 620                 if (r) {
 621                         nfc_err(&client->dev, "No platform data\n");
 622                         return r;
 623                 }
 624         } else if (pdata) {
 625                 r = st21nfca_hci_i2c_request_resources(client);
 626                 if (r) {
 627                         nfc_err(&client->dev, "Cannot get platform resources\n");
 628                         return r;
 629                 }
 630         } else {
 631                 nfc_err(&client->dev, "st21nfca platform resources not available\n");
 632                 return -ENODEV;
 633         }
 634
 635         r = st21nfca_hci_platform_init(phy);
 636         if (r < 0) {
 637                 nfc_err(&client->dev, "Unable to reboot st21nfca\n");
 638                 return r;
 639         }
 640
 641         r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 642                                 st21nfca_hci_irq_thread_fn,
 643                                 phy->irq_polarity | IRQF_ONESHOT,
 644                                 ST21NFCA_HCI_DRIVER_NAME, phy);
 645         if (r < 0) {
 646                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 647                 return r;
 648         }
 649
 650         return st21nfca_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
 651                                         ST21NFCA_FRAME_HEADROOM,
 652                                         ST21NFCA_FRAME_TAILROOM,
 653                                         ST21NFCA_HCI_LLC_MAX_PAYLOAD,
 654                                         &phy->hdev,
 655                                         &phy->se_status);
 656 }
 657
 658 static int st21nfca_hci_i2c_remove(struct i2c_client *client)
 659 {
 660         struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 661
 662         dev_dbg(&client->dev, "%s\n", __func__);
 663
 664         st21nfca_hci_remove(phy->hdev);
 665
 666         if (phy->powered)
 667                 st21nfca_hci_i2c_disable(phy);
 668
 669         return 0;
 670 }
 671
 672 #ifdef CONFIG_OF
 673 static const struct of_device_id of_st21nfca_i2c_match[] = {
 674         { .compatible = "st,st21nfca-i2c", },
 675         { .compatible = "st,st21nfca_i2c", },
 676         {}
 677 };
 678 MODULE_DEVICE_TABLE(of, of_st21nfca_i2c_match);
 679 #endif
 680
 681 static struct i2c_driver st21nfca_hci_i2c_driver = {
 682         .driver = {
 683                 .owner = THIS_MODULE,
 684                 .name = ST21NFCA_HCI_I2C_DRIVER_NAME,
 685                 .of_match_table = of_match_ptr(of_st21nfca_i2c_match),
 686         },
 687         .probe = st21nfca_hci_i2c_probe,
 688         .id_table = st21nfca_hci_i2c_id_table,
 689         .remove = st21nfca_hci_i2c_remove,
 690 };
 691
 692 module_i2c_driver(st21nfca_hci_i2c_driver);
 693
 694 MODULE_LICENSE("GPL");
 695 MODULE_DESCRIPTION(DRIVER_DESC);