linux/drivers/nfc/st21nfca/i2c.c
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   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/gpio/consumer.h>
  25#include <linux/of_irq.h>
  26#include <linux/of_gpio.h>
  27#include <linux/acpi.h>
  28#include <linux/miscdevice.h>
  29#include <linux/interrupt.h>
  30#include <linux/delay.h>
  31#include <linux/nfc.h>
  32#include <linux/firmware.h>
  33#include <linux/platform_data/st21nfca.h>
  34#include <asm/unaligned.h>
  35
  36#include <net/nfc/hci.h>
  37#include <net/nfc/llc.h>
  38#include <net/nfc/nfc.h>
  39
  40#include "st21nfca.h"
  41
  42/*
  43 * Every frame starts with ST21NFCA_SOF_EOF and ends with ST21NFCA_SOF_EOF.
  44 * Because ST21NFCA_SOF_EOF is a possible data value, there is a mecanism
  45 * called byte stuffing has been introduced.
  46 *
  47 * if byte == ST21NFCA_SOF_EOF or ST21NFCA_ESCAPE_BYTE_STUFFING
  48 * - insert ST21NFCA_ESCAPE_BYTE_STUFFING (escape byte)
  49 * - xor byte with ST21NFCA_BYTE_STUFFING_MASK
  50 */
  51#define ST21NFCA_SOF_EOF                0x7e
  52#define ST21NFCA_BYTE_STUFFING_MASK     0x20
  53#define ST21NFCA_ESCAPE_BYTE_STUFFING   0x7d
  54
  55/* SOF + 00 */
  56#define ST21NFCA_FRAME_HEADROOM                 2
  57
  58/* 2 bytes crc + EOF */
  59#define ST21NFCA_FRAME_TAILROOM 3
  60#define IS_START_OF_FRAME(buf) (buf[0] == ST21NFCA_SOF_EOF && \
  61                                buf[1] == 0)
  62
  63#define ST21NFCA_HCI_I2C_DRIVER_NAME "st21nfca_hci_i2c"
  64
  65#define ST21NFCA_GPIO_NAME_EN "enable"
  66
  67struct st21nfca_i2c_phy {
  68        struct i2c_client *i2c_dev;
  69        struct nfc_hci_dev *hdev;
  70
  71        unsigned int gpio_ena;
  72        unsigned int irq_polarity;
  73
  74        struct st21nfca_se_status se_status;
  75
  76        struct sk_buff *pending_skb;
  77        int current_read_len;
  78        /*
  79         * crc might have fail because i2c macro
  80         * is disable due to other interface activity
  81         */
  82        int crc_trials;
  83
  84        int powered;
  85        int run_mode;
  86
  87        /*
  88         * < 0 if hardware error occured (e.g. i2c err)
  89         * and prevents normal operation.
  90         */
  91        int hard_fault;
  92        struct mutex phy_lock;
  93};
  94
  95static u8 len_seq[] = { 16, 24, 12, 29 };
  96static u16 wait_tab[] = { 2, 3, 5, 15, 20, 40};
  97
  98#define I2C_DUMP_SKB(info, skb)                                 \
  99do {                                                            \
 100        pr_debug("%s:\n", info);                                \
 101        print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \
 102                       16, 1, (skb)->data, (skb)->len, 0);      \
 103} while (0)
 104
 105/*
 106 * In order to get the CLF in a known state we generate an internal reboot
 107 * using a proprietary command.
 108 * Once the reboot is completed, we expect to receive a ST21NFCA_SOF_EOF
 109 * fill buffer.
 110 */
 111static int st21nfca_hci_platform_init(struct st21nfca_i2c_phy *phy)
 112{
 113        u16 wait_reboot[] = { 50, 300, 1000 };
 114        char reboot_cmd[] = { 0x7E, 0x66, 0x48, 0xF6, 0x7E };
 115        u8 tmp[ST21NFCA_HCI_LLC_MAX_SIZE];
 116        int i, r = -1;
 117
 118        for (i = 0; i < ARRAY_SIZE(wait_reboot) && r < 0; i++) {
 119                r = i2c_master_send(phy->i2c_dev, reboot_cmd,
 120                                    sizeof(reboot_cmd));
 121                if (r < 0)
 122                        msleep(wait_reboot[i]);
 123        }
 124        if (r < 0)
 125                return r;
 126
 127        /* CLF is spending about 20ms to do an internal reboot */
 128        msleep(20);
 129        r = -1;
 130        for (i = 0; i < ARRAY_SIZE(wait_reboot) && r < 0; i++) {
 131                r = i2c_master_recv(phy->i2c_dev, tmp,
 132                                    ST21NFCA_HCI_LLC_MAX_SIZE);
 133                if (r < 0)
 134                        msleep(wait_reboot[i]);
 135        }
 136        if (r < 0)
 137                return r;
 138
 139        for (i = 0; i < ST21NFCA_HCI_LLC_MAX_SIZE &&
 140                tmp[i] == ST21NFCA_SOF_EOF; i++)
 141                ;
 142
 143        if (r != ST21NFCA_HCI_LLC_MAX_SIZE)
 144                return -ENODEV;
 145
 146        usleep_range(1000, 1500);
 147        return 0;
 148}
 149
 150static int st21nfca_hci_i2c_enable(void *phy_id)
 151{
 152        struct st21nfca_i2c_phy *phy = phy_id;
 153
 154        gpio_set_value(phy->gpio_ena, 1);
 155        phy->powered = 1;
 156        phy->run_mode = ST21NFCA_HCI_MODE;
 157
 158        usleep_range(10000, 15000);
 159
 160        return 0;
 161}
 162
 163static void st21nfca_hci_i2c_disable(void *phy_id)
 164{
 165        struct st21nfca_i2c_phy *phy = phy_id;
 166
 167        gpio_set_value(phy->gpio_ena, 0);
 168
 169        phy->powered = 0;
 170}
 171
 172static void st21nfca_hci_add_len_crc(struct sk_buff *skb)
 173{
 174        u16 crc;
 175        u8 tmp;
 176
 177        *skb_push(skb, 1) = 0;
 178
 179        crc = crc_ccitt(0xffff, skb->data, skb->len);
 180        crc = ~crc;
 181
 182        tmp = crc & 0x00ff;
 183        *skb_put(skb, 1) = tmp;
 184
 185        tmp = (crc >> 8) & 0x00ff;
 186        *skb_put(skb, 1) = tmp;
 187}
 188
 189static void st21nfca_hci_remove_len_crc(struct sk_buff *skb)
 190{
 191        skb_pull(skb, ST21NFCA_FRAME_HEADROOM);
 192        skb_trim(skb, skb->len - ST21NFCA_FRAME_TAILROOM);
 193}
 194
 195/*
 196 * Writing a frame must not return the number of written bytes.
 197 * It must return either zero for success, or <0 for error.
 198 * In addition, it must not alter the skb
 199 */
 200static int st21nfca_hci_i2c_write(void *phy_id, struct sk_buff *skb)
 201{
 202        int r = -1, i, j;
 203        struct st21nfca_i2c_phy *phy = phy_id;
 204        struct i2c_client *client = phy->i2c_dev;
 205        u8 tmp[ST21NFCA_HCI_LLC_MAX_SIZE * 2];
 206
 207        I2C_DUMP_SKB("st21nfca_hci_i2c_write", skb);
 208
 209        if (phy->hard_fault != 0)
 210                return phy->hard_fault;
 211
 212        /*
 213         * Compute CRC before byte stuffing computation on frame
 214         * Note st21nfca_hci_add_len_crc is doing a byte stuffing
 215         * on its own value
 216         */
 217        st21nfca_hci_add_len_crc(skb);
 218
 219        /* add ST21NFCA_SOF_EOF on tail */
 220        *skb_put(skb, 1) = ST21NFCA_SOF_EOF;
 221        /* add ST21NFCA_SOF_EOF on head */
 222        *skb_push(skb, 1) = ST21NFCA_SOF_EOF;
 223
 224        /*
 225         * Compute byte stuffing
 226         * if byte == ST21NFCA_SOF_EOF or ST21NFCA_ESCAPE_BYTE_STUFFING
 227         * insert ST21NFCA_ESCAPE_BYTE_STUFFING (escape byte)
 228         * xor byte with ST21NFCA_BYTE_STUFFING_MASK
 229         */
 230        tmp[0] = skb->data[0];
 231        for (i = 1, j = 1; i < skb->len - 1; i++, j++) {
 232                if (skb->data[i] == ST21NFCA_SOF_EOF
 233                    || skb->data[i] == ST21NFCA_ESCAPE_BYTE_STUFFING) {
 234                        tmp[j] = ST21NFCA_ESCAPE_BYTE_STUFFING;
 235                        j++;
 236                        tmp[j] = skb->data[i] ^ ST21NFCA_BYTE_STUFFING_MASK;
 237                } else {
 238                        tmp[j] = skb->data[i];
 239                }
 240        }
 241        tmp[j] = skb->data[i];
 242        j++;
 243
 244        /*
 245         * Manage sleep mode
 246         * Try 3 times to send data with delay between each
 247         */
 248        mutex_lock(&phy->phy_lock);
 249        for (i = 0; i < ARRAY_SIZE(wait_tab) && r < 0; i++) {
 250                r = i2c_master_send(client, tmp, j);
 251                if (r < 0)
 252                        msleep(wait_tab[i]);
 253        }
 254        mutex_unlock(&phy->phy_lock);
 255
 256        if (r >= 0) {
 257                if (r != j)
 258                        r = -EREMOTEIO;
 259                else
 260                        r = 0;
 261        }
 262
 263        st21nfca_hci_remove_len_crc(skb);
 264
 265        return r;
 266}
 267
 268static int get_frame_size(u8 *buf, int buflen)
 269{
 270        int len = 0;
 271
 272        if (buf[len + 1] == ST21NFCA_SOF_EOF)
 273                return 0;
 274
 275        for (len = 1; len < buflen && buf[len] != ST21NFCA_SOF_EOF; len++)
 276                ;
 277
 278        return len;
 279}
 280
 281static int check_crc(u8 *buf, int buflen)
 282{
 283        u16 crc;
 284
 285        crc = crc_ccitt(0xffff, buf, buflen - 2);
 286        crc = ~crc;
 287
 288        if (buf[buflen - 2] != (crc & 0xff) || buf[buflen - 1] != (crc >> 8)) {
 289                pr_err(ST21NFCA_HCI_DRIVER_NAME
 290                       ": CRC error 0x%x != 0x%x 0x%x\n", crc, buf[buflen - 1],
 291                       buf[buflen - 2]);
 292
 293                pr_info(DRIVER_DESC ": %s : BAD CRC\n", __func__);
 294                print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
 295                               16, 2, buf, buflen, false);
 296                return -EPERM;
 297        }
 298        return 0;
 299}
 300
 301/*
 302 * Prepare received data for upper layer.
 303 * Received data include byte stuffing, crc and sof/eof
 304 * which is not usable by hci part.
 305 * returns:
 306 * frame size without sof/eof, header and byte stuffing
 307 * -EBADMSG : frame was incorrect and discarded
 308 */
 309static int st21nfca_hci_i2c_repack(struct sk_buff *skb)
 310{
 311        int i, j, r, size;
 312
 313        if (skb->len < 1 || (skb->len > 1 && skb->data[1] != 0))
 314                return -EBADMSG;
 315
 316        size = get_frame_size(skb->data, skb->len);
 317        if (size > 0) {
 318                skb_trim(skb, size);
 319                /* remove ST21NFCA byte stuffing for upper layer */
 320                for (i = 1, j = 0; i < skb->len; i++) {
 321                        if (skb->data[i + j] ==
 322                                        (u8) ST21NFCA_ESCAPE_BYTE_STUFFING) {
 323                                skb->data[i] = skb->data[i + j + 1]
 324                                                | ST21NFCA_BYTE_STUFFING_MASK;
 325                                i++;
 326                                j++;
 327                        }
 328                        skb->data[i] = skb->data[i + j];
 329                }
 330                /* remove byte stuffing useless byte */
 331                skb_trim(skb, i - j);
 332                /* remove ST21NFCA_SOF_EOF from head */
 333                skb_pull(skb, 1);
 334
 335                r = check_crc(skb->data, skb->len);
 336                if (r != 0) {
 337                        i = 0;
 338                        return -EBADMSG;
 339                }
 340
 341                /* remove headbyte */
 342                skb_pull(skb, 1);
 343                /* remove crc. Byte Stuffing is already removed here */
 344                skb_trim(skb, skb->len - 2);
 345                return skb->len;
 346        }
 347        return 0;
 348}
 349
 350/*
 351 * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
 352 * that i2c bus will be flushed and that next read will start on a new frame.
 353 * returned skb contains only LLC header and payload.
 354 * returns:
 355 * frame size : if received frame is complete (find ST21NFCA_SOF_EOF at
 356 * end of read)
 357 * -EAGAIN : if received frame is incomplete (not find ST21NFCA_SOF_EOF
 358 * at end of read)
 359 * -EREMOTEIO : i2c read error (fatal)
 360 * -EBADMSG : frame was incorrect and discarded
 361 * (value returned from st21nfca_hci_i2c_repack)
 362 * -EIO : if no ST21NFCA_SOF_EOF is found after reaching
 363 * the read length end sequence
 364 */
 365static int st21nfca_hci_i2c_read(struct st21nfca_i2c_phy *phy,
 366                                 struct sk_buff *skb)
 367{
 368        int r, i;
 369        u8 len;
 370        u8 buf[ST21NFCA_HCI_LLC_MAX_PAYLOAD];
 371        struct i2c_client *client = phy->i2c_dev;
 372
 373        if (phy->current_read_len < ARRAY_SIZE(len_seq)) {
 374                len = len_seq[phy->current_read_len];
 375
 376                /*
 377                 * Add retry mecanism
 378                 * Operation on I2C interface may fail in case of operation on
 379                 * RF or SWP interface
 380                 */
 381                r = 0;
 382                mutex_lock(&phy->phy_lock);
 383                for (i = 0; i < ARRAY_SIZE(wait_tab) && r <= 0; i++) {
 384                        r = i2c_master_recv(client, buf, len);
 385                        if (r < 0)
 386                                msleep(wait_tab[i]);
 387                }
 388                mutex_unlock(&phy->phy_lock);
 389
 390                if (r != len) {
 391                        phy->current_read_len = 0;
 392                        return -EREMOTEIO;
 393                }
 394
 395                /*
 396                 * The first read sequence does not start with SOF.
 397                 * Data is corrupeted so we drop it.
 398                 */
 399                if (!phy->current_read_len && !IS_START_OF_FRAME(buf)) {
 400                        skb_trim(skb, 0);
 401                        phy->current_read_len = 0;
 402                        return -EIO;
 403                } else if (phy->current_read_len && IS_START_OF_FRAME(buf)) {
 404                        /*
 405                         * Previous frame transmission was interrupted and
 406                         * the frame got repeated.
 407                         * Received frame start with ST21NFCA_SOF_EOF + 00.
 408                         */
 409                        skb_trim(skb, 0);
 410                        phy->current_read_len = 0;
 411                }
 412
 413                memcpy(skb_put(skb, len), buf, len);
 414
 415                if (skb->data[skb->len - 1] == ST21NFCA_SOF_EOF) {
 416                        phy->current_read_len = 0;
 417                        return st21nfca_hci_i2c_repack(skb);
 418                }
 419                phy->current_read_len++;
 420                return -EAGAIN;
 421        }
 422        return -EIO;
 423}
 424
 425/*
 426 * Reads an shdlc frame from the chip. This is not as straightforward as it
 427 * seems. The frame format is data-crc, and corruption can occur anywhere
 428 * while transiting on i2c bus, such that we could read an invalid data.
 429 * The tricky case is when we read a corrupted data or crc. We must detect
 430 * this here in order to determine that data can be transmitted to the hci
 431 * core. This is the reason why we check the crc here.
 432 * The CLF will repeat a frame until we send a RR on that frame.
 433 *
 434 * On ST21NFCA, IRQ goes in idle when read starts. As no size information are
 435 * available in the incoming data, other IRQ might come. Every IRQ will trigger
 436 * a read sequence with different length and will fill the current frame.
 437 * The reception is complete once we reach a ST21NFCA_SOF_EOF.
 438 */
 439static irqreturn_t st21nfca_hci_irq_thread_fn(int irq, void *phy_id)
 440{
 441        struct st21nfca_i2c_phy *phy = phy_id;
 442        struct i2c_client *client;
 443
 444        int r;
 445
 446        if (!phy || irq != phy->i2c_dev->irq) {
 447                WARN_ON_ONCE(1);
 448                return IRQ_NONE;
 449        }
 450
 451        client = phy->i2c_dev;
 452        dev_dbg(&client->dev, "IRQ\n");
 453
 454        if (phy->hard_fault != 0)
 455                return IRQ_HANDLED;
 456
 457        r = st21nfca_hci_i2c_read(phy, phy->pending_skb);
 458        if (r == -EREMOTEIO) {
 459                phy->hard_fault = r;
 460
 461                nfc_hci_recv_frame(phy->hdev, NULL);
 462
 463                return IRQ_HANDLED;
 464        } else if (r == -EAGAIN || r == -EIO) {
 465                return IRQ_HANDLED;
 466        } else if (r == -EBADMSG && phy->crc_trials < ARRAY_SIZE(wait_tab)) {
 467                /*
 468                 * With ST21NFCA, only one interface (I2C, RF or SWP)
 469                 * may be active at a time.
 470                 * Having incorrect crc is usually due to i2c macrocell
 471                 * deactivation in the middle of a transmission.
 472                 * It may generate corrupted data on i2c.
 473                 * We give sometime to get i2c back.
 474                 * The complete frame will be repeated.
 475                 */
 476                msleep(wait_tab[phy->crc_trials]);
 477                phy->crc_trials++;
 478                phy->current_read_len = 0;
 479                kfree_skb(phy->pending_skb);
 480        } else if (r > 0) {
 481                /*
 482                 * We succeeded to read data from the CLF and
 483                 * data is valid.
 484                 * Reset counter.
 485                 */
 486                nfc_hci_recv_frame(phy->hdev, phy->pending_skb);
 487                phy->crc_trials = 0;
 488        } else {
 489                kfree_skb(phy->pending_skb);
 490        }
 491
 492        phy->pending_skb = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE * 2, GFP_KERNEL);
 493        if (phy->pending_skb == NULL) {
 494                phy->hard_fault = -ENOMEM;
 495                nfc_hci_recv_frame(phy->hdev, NULL);
 496        }
 497
 498        return IRQ_HANDLED;
 499}
 500
 501static struct nfc_phy_ops i2c_phy_ops = {
 502        .write = st21nfca_hci_i2c_write,
 503        .enable = st21nfca_hci_i2c_enable,
 504        .disable = st21nfca_hci_i2c_disable,
 505};
 506
 507static int st21nfca_hci_i2c_acpi_request_resources(struct i2c_client *client)
 508{
 509        struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 510        struct gpio_desc *gpiod_ena;
 511        struct device *dev = &client->dev;
 512        u8 tmp;
 513
 514        /* Get EN GPIO from ACPI */
 515        gpiod_ena = devm_gpiod_get_index(dev, ST21NFCA_GPIO_NAME_EN, 1,
 516                                         GPIOD_OUT_LOW);
 517        if (!IS_ERR(gpiod_ena)) {
 518                nfc_err(dev, "Unable to get ENABLE GPIO\n");
 519                return -ENODEV;
 520        }
 521
 522        phy->gpio_ena = desc_to_gpio(gpiod_ena);
 523
 524        phy->irq_polarity = irq_get_trigger_type(client->irq);
 525
 526        phy->se_status.is_ese_present = false;
 527        phy->se_status.is_uicc_present = false;
 528
 529        if (device_property_present(dev, "ese-present")) {
 530                device_property_read_u8(dev, "ese-present", &tmp);
 531                phy->se_status.is_ese_present = tmp;
 532        }
 533
 534        if (device_property_present(dev, "uicc-present")) {
 535                device_property_read_u8(dev, "uicc-present", &tmp);
 536                phy->se_status.is_uicc_present = tmp;
 537        }
 538
 539        return 0;
 540}
 541
 542static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client)
 543{
 544        struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 545        struct device_node *pp;
 546        int gpio;
 547        int r;
 548
 549        pp = client->dev.of_node;
 550        if (!pp)
 551                return -ENODEV;
 552
 553        /* Get GPIO from device tree */
 554        gpio = of_get_named_gpio(pp, "enable-gpios", 0);
 555        if (gpio < 0) {
 556                nfc_err(&client->dev, "Failed to retrieve enable-gpios from device tree\n");
 557                return gpio;
 558        }
 559
 560        /* GPIO request and configuration */
 561        r = devm_gpio_request_one(&client->dev, gpio, GPIOF_OUT_INIT_HIGH,
 562                                  ST21NFCA_GPIO_NAME_EN);
 563        if (r) {
 564                nfc_err(&client->dev, "Failed to request enable pin\n");
 565                return r;
 566        }
 567
 568        phy->gpio_ena = gpio;
 569
 570        phy->irq_polarity = irq_get_trigger_type(client->irq);
 571
 572        phy->se_status.is_ese_present =
 573                                of_property_read_bool(pp, "ese-present");
 574        phy->se_status.is_uicc_present =
 575                                of_property_read_bool(pp, "uicc-present");
 576
 577        return 0;
 578}
 579
 580static int st21nfca_hci_i2c_request_resources(struct i2c_client *client)
 581{
 582        struct st21nfca_nfc_platform_data *pdata;
 583        struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 584        int r;
 585
 586        pdata = client->dev.platform_data;
 587        if (pdata == NULL) {
 588                nfc_err(&client->dev, "No platform data\n");
 589                return -EINVAL;
 590        }
 591
 592        /* store for later use */
 593        phy->gpio_ena = pdata->gpio_ena;
 594        phy->irq_polarity = pdata->irq_polarity;
 595
 596        if (phy->gpio_ena > 0) {
 597                r = devm_gpio_request_one(&client->dev, phy->gpio_ena,
 598                                          GPIOF_OUT_INIT_HIGH,
 599                                          ST21NFCA_GPIO_NAME_EN);
 600                if (r) {
 601                        pr_err("%s : ena gpio_request failed\n", __FILE__);
 602                        return r;
 603                }
 604        }
 605
 606        phy->se_status.is_ese_present = pdata->is_ese_present;
 607        phy->se_status.is_uicc_present = pdata->is_uicc_present;
 608
 609        return 0;
 610}
 611
 612static int st21nfca_hci_i2c_probe(struct i2c_client *client,
 613                                  const struct i2c_device_id *id)
 614{
 615        struct st21nfca_i2c_phy *phy;
 616        struct st21nfca_nfc_platform_data *pdata;
 617        int r;
 618
 619        dev_dbg(&client->dev, "%s\n", __func__);
 620        dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
 621
 622        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 623                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 624                return -ENODEV;
 625        }
 626
 627        phy = devm_kzalloc(&client->dev, sizeof(struct st21nfca_i2c_phy),
 628                           GFP_KERNEL);
 629        if (!phy)
 630                return -ENOMEM;
 631
 632        phy->i2c_dev = client;
 633        phy->pending_skb = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE * 2, GFP_KERNEL);
 634        if (phy->pending_skb == NULL)
 635                return -ENOMEM;
 636
 637        phy->current_read_len = 0;
 638        phy->crc_trials = 0;
 639        mutex_init(&phy->phy_lock);
 640        i2c_set_clientdata(client, phy);
 641
 642        pdata = client->dev.platform_data;
 643        if (!pdata && client->dev.of_node) {
 644                r = st21nfca_hci_i2c_of_request_resources(client);
 645                if (r) {
 646                        nfc_err(&client->dev, "No platform data\n");
 647                        return r;
 648                }
 649        } else if (pdata) {
 650                r = st21nfca_hci_i2c_request_resources(client);
 651                if (r) {
 652                        nfc_err(&client->dev, "Cannot get platform resources\n");
 653                        return r;
 654                }
 655        } else if (ACPI_HANDLE(&client->dev)) {
 656                r = st21nfca_hci_i2c_acpi_request_resources(client);
 657                if (r) {
 658                        nfc_err(&client->dev, "Cannot get ACPI data\n");
 659                        return r;
 660                }
 661        } else {
 662                nfc_err(&client->dev, "st21nfca platform resources not available\n");
 663                return -ENODEV;
 664        }
 665
 666        r = st21nfca_hci_platform_init(phy);
 667        if (r < 0) {
 668                nfc_err(&client->dev, "Unable to reboot st21nfca\n");
 669                return r;
 670        }
 671
 672        r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 673                                st21nfca_hci_irq_thread_fn,
 674                                phy->irq_polarity | IRQF_ONESHOT,
 675                                ST21NFCA_HCI_DRIVER_NAME, phy);
 676        if (r < 0) {
 677                nfc_err(&client->dev, "Unable to register IRQ handler\n");
 678                return r;
 679        }
 680
 681        return st21nfca_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
 682                                        ST21NFCA_FRAME_HEADROOM,
 683                                        ST21NFCA_FRAME_TAILROOM,
 684                                        ST21NFCA_HCI_LLC_MAX_PAYLOAD,
 685                                        &phy->hdev,
 686                                        &phy->se_status);
 687}
 688
 689static int st21nfca_hci_i2c_remove(struct i2c_client *client)
 690{
 691        struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
 692
 693        dev_dbg(&client->dev, "%s\n", __func__);
 694
 695        st21nfca_hci_remove(phy->hdev);
 696
 697        if (phy->powered)
 698                st21nfca_hci_i2c_disable(phy);
 699
 700        return 0;
 701}
 702
 703static struct i2c_device_id st21nfca_hci_i2c_id_table[] = {
 704        {ST21NFCA_HCI_DRIVER_NAME, 0},
 705        {}
 706};
 707MODULE_DEVICE_TABLE(i2c, st21nfca_hci_i2c_id_table);
 708
 709static const struct acpi_device_id st21nfca_hci_i2c_acpi_match[] = {
 710        {"SMO2100", 0},
 711        {}
 712};
 713MODULE_DEVICE_TABLE(acpi, st21nfca_hci_i2c_acpi_match);
 714
 715static const struct of_device_id of_st21nfca_i2c_match[] = {
 716        { .compatible = "st,st21nfca-i2c", },
 717        { .compatible = "st,st21nfca_i2c", },
 718        {}
 719};
 720MODULE_DEVICE_TABLE(of, of_st21nfca_i2c_match);
 721
 722static struct i2c_driver st21nfca_hci_i2c_driver = {
 723        .driver = {
 724                .name = ST21NFCA_HCI_I2C_DRIVER_NAME,
 725                .of_match_table = of_match_ptr(of_st21nfca_i2c_match),
 726                .acpi_match_table = ACPI_PTR(st21nfca_hci_i2c_acpi_match),
 727        },
 728        .probe = st21nfca_hci_i2c_probe,
 729        .id_table = st21nfca_hci_i2c_id_table,
 730        .remove = st21nfca_hci_i2c_remove,
 731};
 732module_i2c_driver(st21nfca_hci_i2c_driver);
 733
 734MODULE_LICENSE("GPL");
 735MODULE_DESCRIPTION(DRIVER_DESC);
 736