drivers/nfc/nxp-nci/i2c.c

   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
  49 struct 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         unsigned int gpio_irq;
  56
  57         int hard_fault; /*
  58                          * < 0 if hardware error occurred (e.g. i2c err)
  59                          * and prevents normal operation.
  60                          */
  61 };
  62
  63 static int nxp_nci_i2c_set_mode(void *phy_id,
  64                                     enum nxp_nci_mode mode)
  65 {
  66         struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
  67
  68         gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
  69         gpio_set_value(phy->gpio_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
  70         usleep_range(10000, 15000);
  71
  72         if (mode == NXP_NCI_MODE_COLD)
  73                 phy->hard_fault = 0;
  74
  75         return 0;
  76 }
  77
  78 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
  79 {
  80         int r;
  81         struct nxp_nci_i2c_phy *phy = phy_id;
  82         struct i2c_client *client = phy->i2c_dev;
  83
  84         if (phy->hard_fault != 0)
  85                 return phy->hard_fault;
  86
  87         r = i2c_master_send(client, skb->data, skb->len);
  88         if (r == -EREMOTEIO) {
  89                 /* Retry, chip was in standby */
  90                 usleep_range(110000, 120000);
  91                 r = i2c_master_send(client, skb->data, skb->len);
  92         }
  93
  94         if (r < 0) {
  95                 nfc_err(&client->dev, "Error %d on I2C send\n", r);
  96         } else if (r != skb->len) {
  97                 nfc_err(&client->dev,
  98                         "Invalid length sent: %u (expected %u)\n",
  99                         r, skb->len);
 100                 r = -EREMOTEIO;
 101         } else {
 102                 /* Success but return 0 and not number of bytes */
 103                 r = 0;
 104         }
 105
 106         return r;
 107 }
 108
 109 static const struct nxp_nci_phy_ops i2c_phy_ops = {
 110         .set_mode = nxp_nci_i2c_set_mode,
 111         .write = nxp_nci_i2c_write,
 112 };
 113
 114 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
 115                                struct sk_buff **skb)
 116 {
 117         struct i2c_client *client = phy->i2c_dev;
 118         u16 header;
 119         size_t frame_len;
 120         int r;
 121
 122         r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
 123         if (r < 0) {
 124                 goto fw_read_exit;
 125         } else if (r != NXP_NCI_FW_HDR_LEN) {
 126                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 127                 r = -EBADMSG;
 128                 goto fw_read_exit;
 129         }
 130
 131         frame_len = (get_unaligned_be16(&header) & NXP_NCI_FW_FRAME_LEN_MASK) +
 132                     NXP_NCI_FW_CRC_LEN;
 133
 134         *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
 135         if (*skb == NULL) {
 136                 r = -ENOMEM;
 137                 goto fw_read_exit;
 138         }
 139
 140         memcpy(skb_put(*skb, NXP_NCI_FW_HDR_LEN), &header, NXP_NCI_FW_HDR_LEN);
 141
 142         r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
 143         if (r != frame_len) {
 144                 nfc_err(&client->dev,
 145                         "Invalid frame length: %u (expected %zu)\n",
 146                         r, frame_len);
 147                 r = -EBADMSG;
 148                 goto fw_read_exit_free_skb;
 149         }
 150
 151         return 0;
 152
 153 fw_read_exit_free_skb:
 154         kfree_skb(*skb);
 155 fw_read_exit:
 156         return r;
 157 }
 158
 159 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
 160                                 struct sk_buff **skb)
 161 {
 162         struct nci_ctrl_hdr header; /* May actually be a data header */
 163         struct i2c_client *client = phy->i2c_dev;
 164         int r;
 165
 166         r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
 167         if (r < 0) {
 168                 goto nci_read_exit;
 169         } else if (r != NCI_CTRL_HDR_SIZE) {
 170                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 171                 r = -EBADMSG;
 172                 goto nci_read_exit;
 173         }
 174
 175         *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
 176         if (*skb == NULL) {
 177                 r = -ENOMEM;
 178                 goto nci_read_exit;
 179         }
 180
 181         memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), (void *) &header,
 182                NCI_CTRL_HDR_SIZE);
 183
 184         r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
 185         if (r != header.plen) {
 186                 nfc_err(&client->dev,
 187                         "Invalid frame payload length: %u (expected %u)\n",
 188                         r, header.plen);
 189                 r = -EBADMSG;
 190                 goto nci_read_exit_free_skb;
 191         }
 192
 193         return 0;
 194
 195 nci_read_exit_free_skb:
 196         kfree_skb(*skb);
 197 nci_read_exit:
 198         return r;
 199 }
 200
 201 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
 202 {
 203         struct nxp_nci_i2c_phy *phy = phy_id;
 204         struct i2c_client *client;
 205         struct nxp_nci_info *info;
 206
 207         struct sk_buff *skb = NULL;
 208         int r = 0;
 209
 210         if (!phy || !phy->ndev)
 211                 goto exit_irq_none;
 212
 213         client = phy->i2c_dev;
 214
 215         if (!client || irq != client->irq)
 216                 goto exit_irq_none;
 217
 218         info = nci_get_drvdata(phy->ndev);
 219
 220         if (!info)
 221                 goto exit_irq_none;
 222
 223         mutex_lock(&info->info_lock);
 224
 225         if (phy->hard_fault != 0)
 226                 goto exit_irq_handled;
 227
 228         switch (info->mode) {
 229         case NXP_NCI_MODE_NCI:
 230                 r = nxp_nci_i2c_nci_read(phy, &skb);
 231                 break;
 232         case NXP_NCI_MODE_FW:
 233                 r = nxp_nci_i2c_fw_read(phy, &skb);
 234                 break;
 235         case NXP_NCI_MODE_COLD:
 236                 r = -EREMOTEIO;
 237                 break;
 238         }
 239
 240         if (r == -EREMOTEIO) {
 241                 phy->hard_fault = r;
 242                 skb = NULL;
 243         } else if (r < 0) {
 244                 nfc_err(&client->dev, "Read failed with error %d\n", r);
 245                 goto exit_irq_handled;
 246         }
 247
 248         switch (info->mode) {
 249         case NXP_NCI_MODE_NCI:
 250                 nci_recv_frame(phy->ndev, skb);
 251                 break;
 252         case NXP_NCI_MODE_FW:
 253                 nxp_nci_fw_recv_frame(phy->ndev, skb);
 254                 break;
 255         case NXP_NCI_MODE_COLD:
 256                 break;
 257         }
 258
 259 exit_irq_handled:
 260         mutex_unlock(&info->info_lock);
 261         return IRQ_HANDLED;
 262 exit_irq_none:
 263         WARN_ON_ONCE(1);
 264         return IRQ_NONE;
 265 }
 266
 267 #ifdef CONFIG_OF
 268
 269 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
 270 {
 271         struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 272         struct device_node *pp;
 273         int r;
 274
 275         pp = client->dev.of_node;
 276         if (!pp)
 277                 return -ENODEV;
 278
 279         r = of_get_named_gpio(pp, "enable-gpios", 0);
 280         if (r == -EPROBE_DEFER)
 281                 r = of_get_named_gpio(pp, "enable-gpios", 0);
 282         if (r < 0) {
 283                 nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);
 284                 return r;
 285         }
 286         phy->gpio_en = r;
 287
 288         r = of_get_named_gpio(pp, "firmware-gpios", 0);
 289         if (r == -EPROBE_DEFER)
 290                 r = of_get_named_gpio(pp, "firmware-gpios", 0);
 291         if (r < 0) {
 292                 nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);
 293                 return r;
 294         }
 295         phy->gpio_fw = r;
 296
 297         r = irq_of_parse_and_map(pp, 0);
 298         if (r < 0) {
 299                 nfc_err(&client->dev, "Unable to get irq, error: %d\n", r);
 300                 return r;
 301         }
 302         client->irq = r;
 303
 304         return 0;
 305 }
 306
 307 #else
 308
 309 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
 310 {
 311         return -ENODEV;
 312 }
 313
 314 #endif
 315
 316 static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy)
 317 {
 318         struct i2c_client *client = phy->i2c_dev;
 319         struct gpio_desc *gpiod_en, *gpiod_fw, *gpiod_irq;
 320
 321         gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW);
 322         gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW);
 323         gpiod_irq = devm_gpiod_get_index(&client->dev, NULL, 0, GPIOD_IN);
 324
 325         if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw) || IS_ERR(gpiod_irq)) {
 326                 nfc_err(&client->dev, "No GPIOs\n");
 327                 return -EINVAL;
 328         }
 329
 330         client->irq = gpiod_to_irq(gpiod_irq);
 331         if (client->irq < 0) {
 332                 nfc_err(&client->dev, "No IRQ\n");
 333                 return -EINVAL;
 334         }
 335
 336         phy->gpio_en = desc_to_gpio(gpiod_en);
 337         phy->gpio_fw = desc_to_gpio(gpiod_fw);
 338         phy->gpio_irq = desc_to_gpio(gpiod_irq);
 339
 340         return 0;
 341 }
 342
 343 static int nxp_nci_i2c_probe(struct i2c_client *client,
 344                             const struct i2c_device_id *id)
 345 {
 346         struct nxp_nci_i2c_phy *phy;
 347         struct nxp_nci_nfc_platform_data *pdata;
 348         int r;
 349
 350         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 351                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 352                 r = -ENODEV;
 353                 goto probe_exit;
 354         }
 355
 356         phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
 357                            GFP_KERNEL);
 358         if (!phy) {
 359                 r = -ENOMEM;
 360                 goto probe_exit;
 361         }
 362
 363         phy->i2c_dev = client;
 364         i2c_set_clientdata(client, phy);
 365
 366         pdata = client->dev.platform_data;
 367
 368         if (!pdata && client->dev.of_node) {
 369                 r = nxp_nci_i2c_parse_devtree(client);
 370                 if (r < 0) {
 371                         nfc_err(&client->dev, "Failed to get DT data\n");
 372                         goto probe_exit;
 373                 }
 374         } else if (pdata) {
 375                 phy->gpio_en = pdata->gpio_en;
 376                 phy->gpio_fw = pdata->gpio_fw;
 377                 client->irq = pdata->irq;
 378         } else if (ACPI_HANDLE(&client->dev)) {
 379                 r = nxp_nci_i2c_acpi_config(phy);
 380                 if (r < 0)
 381                         goto probe_exit;
 382                 goto nci_probe;
 383         } else {
 384                 nfc_err(&client->dev, "No platform data\n");
 385                 r = -EINVAL;
 386                 goto probe_exit;
 387         }
 388
 389         r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
 390                                   GPIOF_OUT_INIT_LOW, "nxp_nci_en");
 391         if (r < 0)
 392                 goto probe_exit;
 393
 394         r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,
 395                                   GPIOF_OUT_INIT_LOW, "nxp_nci_fw");
 396         if (r < 0)
 397                 goto probe_exit;
 398
 399 nci_probe:
 400         r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
 401                           NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
 402         if (r < 0)
 403                 goto probe_exit;
 404
 405         r = request_threaded_irq(client->irq, NULL,
 406                                  nxp_nci_i2c_irq_thread_fn,
 407                                  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 408                                  NXP_NCI_I2C_DRIVER_NAME, phy);
 409         if (r < 0)
 410                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 411
 412 probe_exit:
 413         return r;
 414 }
 415
 416 static int nxp_nci_i2c_remove(struct i2c_client *client)
 417 {
 418         struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 419
 420         nxp_nci_remove(phy->ndev);
 421         free_irq(client->irq, phy);
 422
 423         return 0;
 424 }
 425
 426 static struct i2c_device_id nxp_nci_i2c_id_table[] = {
 427         {"nxp-nci_i2c", 0},
 428         {}
 429 };
 430 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 431
 432 static const struct of_device_id of_nxp_nci_i2c_match[] = {
 433         { .compatible = "nxp,nxp-nci-i2c", },
 434         {},
 435 };
 436 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 437
 438 #ifdef CONFIG_ACPI
 439 static struct acpi_device_id acpi_id[] = {
 440         { "NXP7471" },
 441         { },
 442 };
 443 MODULE_DEVICE_TABLE(acpi, acpi_id);
 444 #endif
 445
 446 static struct i2c_driver nxp_nci_i2c_driver = {
 447         .driver = {
 448                    .name = NXP_NCI_I2C_DRIVER_NAME,
 449                    .owner  = THIS_MODULE,
 450                    .acpi_match_table = ACPI_PTR(acpi_id),
 451                    .of_match_table = of_match_ptr(of_nxp_nci_i2c_match),
 452                   },
 453         .probe = nxp_nci_i2c_probe,
 454         .id_table = nxp_nci_i2c_id_table,
 455         .remove = nxp_nci_i2c_remove,
 456 };
 457
 458 module_i2c_driver(nxp_nci_i2c_driver);
 459
 460 MODULE_LICENSE("GPL");
 461 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 462 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
 463 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");