linux/drivers/nfc/nxp-nci/i2c.c
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   1/*
   2 * I2C link layer for the NXP NCI driver
   3 *
   4 * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
   5 * Copyright (C) 2012-2015  Intel Corporation. All rights reserved.
   6 *
   7 * Authors: Clément Perrochaud <clement.perrochaud@nxp.com>
   8 * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>
   9 *
  10 * Derived from PN544 device driver:
  11 * Copyright (C) 2012  Intel Corporation. All rights reserved.
  12 *
  13 * This program is free software; you can redistribute it and/or modify it
  14 * under the terms and conditions of the GNU General Public License,
  15 * version 2, as published by the Free Software Foundation.
  16 *
  17 * This program is distributed in the hope that it will be useful,
  18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20 * GNU General Public License for more details.
  21 *
  22 * You should have received a copy of the GNU General Public License
  23 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  24 */
  25
  26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28#include <linux/acpi.h>
  29#include <linux/delay.h>
  30#include <linux/i2c.h>
  31#include <linux/interrupt.h>
  32#include <linux/miscdevice.h>
  33#include <linux/module.h>
  34#include <linux/nfc.h>
  35#include <linux/gpio/consumer.h>
  36#include <linux/of_gpio.h>
  37#include <linux/of_irq.h>
  38#include <linux/platform_data/nxp-nci.h>
  39#include <linux/unaligned/access_ok.h>
  40
  41#include <net/nfc/nfc.h>
  42
  43#include "nxp-nci.h"
  44
  45#define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c"
  46
  47#define NXP_NCI_I2C_MAX_PAYLOAD 32
  48
  49struct nxp_nci_i2c_phy {
  50        struct i2c_client *i2c_dev;
  51        struct nci_dev *ndev;
  52
  53        unsigned int gpio_en;
  54        unsigned int gpio_fw;
  55
  56        int hard_fault; /*
  57                         * < 0 if hardware error occurred (e.g. i2c err)
  58                         * and prevents normal operation.
  59                         */
  60};
  61
  62static int nxp_nci_i2c_set_mode(void *phy_id,
  63                                    enum nxp_nci_mode mode)
  64{
  65        struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
  66
  67        gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
  68        gpio_set_value(phy->gpio_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
  69        usleep_range(10000, 15000);
  70
  71        if (mode == NXP_NCI_MODE_COLD)
  72                phy->hard_fault = 0;
  73
  74        return 0;
  75}
  76
  77static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
  78{
  79        int r;
  80        struct nxp_nci_i2c_phy *phy = phy_id;
  81        struct i2c_client *client = phy->i2c_dev;
  82
  83        if (phy->hard_fault != 0)
  84                return phy->hard_fault;
  85
  86        r = i2c_master_send(client, skb->data, skb->len);
  87        if (r < 0) {
  88                /* Retry, chip was in standby */
  89                usleep_range(110000, 120000);
  90                r = i2c_master_send(client, skb->data, skb->len);
  91        }
  92
  93        if (r < 0) {
  94                nfc_err(&client->dev, "Error %d on I2C send\n", r);
  95        } else if (r != skb->len) {
  96                nfc_err(&client->dev,
  97                        "Invalid length sent: %u (expected %u)\n",
  98                        r, skb->len);
  99                r = -EREMOTEIO;
 100        } else {
 101                /* Success but return 0 and not number of bytes */
 102                r = 0;
 103        }
 104
 105        return r;
 106}
 107
 108static const struct nxp_nci_phy_ops i2c_phy_ops = {
 109        .set_mode = nxp_nci_i2c_set_mode,
 110        .write = nxp_nci_i2c_write,
 111};
 112
 113static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
 114                               struct sk_buff **skb)
 115{
 116        struct i2c_client *client = phy->i2c_dev;
 117        u16 header;
 118        size_t frame_len;
 119        int r;
 120
 121        r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
 122        if (r < 0) {
 123                goto fw_read_exit;
 124        } else if (r != NXP_NCI_FW_HDR_LEN) {
 125                nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 126                r = -EBADMSG;
 127                goto fw_read_exit;
 128        }
 129
 130        frame_len = (get_unaligned_be16(&header) & NXP_NCI_FW_FRAME_LEN_MASK) +
 131                    NXP_NCI_FW_CRC_LEN;
 132
 133        *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
 134        if (*skb == NULL) {
 135                r = -ENOMEM;
 136                goto fw_read_exit;
 137        }
 138
 139        memcpy(skb_put(*skb, NXP_NCI_FW_HDR_LEN), &header, NXP_NCI_FW_HDR_LEN);
 140
 141        r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
 142        if (r != frame_len) {
 143                nfc_err(&client->dev,
 144                        "Invalid frame length: %u (expected %zu)\n",
 145                        r, frame_len);
 146                r = -EBADMSG;
 147                goto fw_read_exit_free_skb;
 148        }
 149
 150        return 0;
 151
 152fw_read_exit_free_skb:
 153        kfree_skb(*skb);
 154fw_read_exit:
 155        return r;
 156}
 157
 158static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
 159                                struct sk_buff **skb)
 160{
 161        struct nci_ctrl_hdr header; /* May actually be a data header */
 162        struct i2c_client *client = phy->i2c_dev;
 163        int r;
 164
 165        r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
 166        if (r < 0) {
 167                goto nci_read_exit;
 168        } else if (r != NCI_CTRL_HDR_SIZE) {
 169                nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 170                r = -EBADMSG;
 171                goto nci_read_exit;
 172        }
 173
 174        *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
 175        if (*skb == NULL) {
 176                r = -ENOMEM;
 177                goto nci_read_exit;
 178        }
 179
 180        memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), (void *) &header,
 181               NCI_CTRL_HDR_SIZE);
 182
 183        r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
 184        if (r != header.plen) {
 185                nfc_err(&client->dev,
 186                        "Invalid frame payload length: %u (expected %u)\n",
 187                        r, header.plen);
 188                r = -EBADMSG;
 189                goto nci_read_exit_free_skb;
 190        }
 191
 192        return 0;
 193
 194nci_read_exit_free_skb:
 195        kfree_skb(*skb);
 196nci_read_exit:
 197        return r;
 198}
 199
 200static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
 201{
 202        struct nxp_nci_i2c_phy *phy = phy_id;
 203        struct i2c_client *client;
 204        struct nxp_nci_info *info;
 205
 206        struct sk_buff *skb = NULL;
 207        int r = 0;
 208
 209        if (!phy || !phy->ndev)
 210                goto exit_irq_none;
 211
 212        client = phy->i2c_dev;
 213
 214        if (!client || irq != client->irq)
 215                goto exit_irq_none;
 216
 217        info = nci_get_drvdata(phy->ndev);
 218
 219        if (!info)
 220                goto exit_irq_none;
 221
 222        mutex_lock(&info->info_lock);
 223
 224        if (phy->hard_fault != 0)
 225                goto exit_irq_handled;
 226
 227        switch (info->mode) {
 228        case NXP_NCI_MODE_NCI:
 229                r = nxp_nci_i2c_nci_read(phy, &skb);
 230                break;
 231        case NXP_NCI_MODE_FW:
 232                r = nxp_nci_i2c_fw_read(phy, &skb);
 233                break;
 234        case NXP_NCI_MODE_COLD:
 235                r = -EREMOTEIO;
 236                break;
 237        }
 238
 239        if (r == -EREMOTEIO) {
 240                phy->hard_fault = r;
 241                skb = NULL;
 242        } else if (r < 0) {
 243                nfc_err(&client->dev, "Read failed with error %d\n", r);
 244                goto exit_irq_handled;
 245        }
 246
 247        switch (info->mode) {
 248        case NXP_NCI_MODE_NCI:
 249                nci_recv_frame(phy->ndev, skb);
 250                break;
 251        case NXP_NCI_MODE_FW:
 252                nxp_nci_fw_recv_frame(phy->ndev, skb);
 253                break;
 254        case NXP_NCI_MODE_COLD:
 255                break;
 256        }
 257
 258exit_irq_handled:
 259        mutex_unlock(&info->info_lock);
 260        return IRQ_HANDLED;
 261exit_irq_none:
 262        WARN_ON_ONCE(1);
 263        return IRQ_NONE;
 264}
 265
 266static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
 267{
 268        struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 269        struct device_node *pp;
 270        int r;
 271
 272        pp = client->dev.of_node;
 273        if (!pp)
 274                return -ENODEV;
 275
 276        r = of_get_named_gpio(pp, "enable-gpios", 0);
 277        if (r == -EPROBE_DEFER)
 278                r = of_get_named_gpio(pp, "enable-gpios", 0);
 279        if (r < 0) {
 280                nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);
 281                return r;
 282        }
 283        phy->gpio_en = r;
 284
 285        r = of_get_named_gpio(pp, "firmware-gpios", 0);
 286        if (r == -EPROBE_DEFER)
 287                r = of_get_named_gpio(pp, "firmware-gpios", 0);
 288        if (r < 0) {
 289                nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);
 290                return r;
 291        }
 292        phy->gpio_fw = r;
 293
 294        return 0;
 295}
 296
 297static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy)
 298{
 299        struct i2c_client *client = phy->i2c_dev;
 300        struct gpio_desc *gpiod_en, *gpiod_fw;
 301
 302        gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW);
 303        gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW);
 304
 305        if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw)) {
 306                nfc_err(&client->dev, "No GPIOs\n");
 307                return -EINVAL;
 308        }
 309
 310        phy->gpio_en = desc_to_gpio(gpiod_en);
 311        phy->gpio_fw = desc_to_gpio(gpiod_fw);
 312
 313        return 0;
 314}
 315
 316static int nxp_nci_i2c_probe(struct i2c_client *client,
 317                            const struct i2c_device_id *id)
 318{
 319        struct nxp_nci_i2c_phy *phy;
 320        struct nxp_nci_nfc_platform_data *pdata;
 321        int r;
 322
 323        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 324                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 325                r = -ENODEV;
 326                goto probe_exit;
 327        }
 328
 329        phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
 330                           GFP_KERNEL);
 331        if (!phy) {
 332                r = -ENOMEM;
 333                goto probe_exit;
 334        }
 335
 336        phy->i2c_dev = client;
 337        i2c_set_clientdata(client, phy);
 338
 339        pdata = client->dev.platform_data;
 340
 341        if (!pdata && client->dev.of_node) {
 342                r = nxp_nci_i2c_parse_devtree(client);
 343                if (r < 0) {
 344                        nfc_err(&client->dev, "Failed to get DT data\n");
 345                        goto probe_exit;
 346                }
 347        } else if (pdata) {
 348                phy->gpio_en = pdata->gpio_en;
 349                phy->gpio_fw = pdata->gpio_fw;
 350        } else if (ACPI_HANDLE(&client->dev)) {
 351                r = nxp_nci_i2c_acpi_config(phy);
 352                if (r < 0)
 353                        goto probe_exit;
 354                goto nci_probe;
 355        } else {
 356                nfc_err(&client->dev, "No platform data\n");
 357                r = -EINVAL;
 358                goto probe_exit;
 359        }
 360
 361        r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
 362                                  GPIOF_OUT_INIT_LOW, "nxp_nci_en");
 363        if (r < 0)
 364                goto probe_exit;
 365
 366        r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,
 367                                  GPIOF_OUT_INIT_LOW, "nxp_nci_fw");
 368        if (r < 0)
 369                goto probe_exit;
 370
 371nci_probe:
 372        r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
 373                          NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
 374        if (r < 0)
 375                goto probe_exit;
 376
 377        r = request_threaded_irq(client->irq, NULL,
 378                                 nxp_nci_i2c_irq_thread_fn,
 379                                 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 380                                 NXP_NCI_I2C_DRIVER_NAME, phy);
 381        if (r < 0)
 382                nfc_err(&client->dev, "Unable to register IRQ handler\n");
 383
 384probe_exit:
 385        return r;
 386}
 387
 388static int nxp_nci_i2c_remove(struct i2c_client *client)
 389{
 390        struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 391
 392        nxp_nci_remove(phy->ndev);
 393        free_irq(client->irq, phy);
 394
 395        return 0;
 396}
 397
 398static struct i2c_device_id nxp_nci_i2c_id_table[] = {
 399        {"nxp-nci_i2c", 0},
 400        {}
 401};
 402MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 403
 404static const struct of_device_id of_nxp_nci_i2c_match[] = {
 405        { .compatible = "nxp,nxp-nci-i2c", },
 406        {},
 407};
 408MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 409
 410#ifdef CONFIG_ACPI
 411static struct acpi_device_id acpi_id[] = {
 412        { "NXP7471" },
 413        { },
 414};
 415MODULE_DEVICE_TABLE(acpi, acpi_id);
 416#endif
 417
 418static struct i2c_driver nxp_nci_i2c_driver = {
 419        .driver = {
 420                   .name = NXP_NCI_I2C_DRIVER_NAME,
 421                   .owner  = THIS_MODULE,
 422                   .acpi_match_table = ACPI_PTR(acpi_id),
 423                   .of_match_table = of_match_ptr(of_nxp_nci_i2c_match),
 424                  },
 425        .probe = nxp_nci_i2c_probe,
 426        .id_table = nxp_nci_i2c_id_table,
 427        .remove = nxp_nci_i2c_remove,
 428};
 429
 430module_i2c_driver(nxp_nci_i2c_driver);
 431
 432MODULE_LICENSE("GPL");
 433MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 434MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
 435MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
 436