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
  56         int hard_fault; /*
  57                          * < 0 if hardware error occurred (e.g. i2c err)
  58                          * and prevents normal operation.
  59                          */
  60 };
  61
  62 static 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
  77 static 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
 108 static 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
 113 static 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
 152 fw_read_exit_free_skb:
 153         kfree_skb(*skb);
 154 fw_read_exit:
 155         return r;
 156 }
 157
 158 static 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
 194 nci_read_exit_free_skb:
 195         kfree_skb(*skb);
 196 nci_read_exit:
 197         return r;
 198 }
 199
 200 static 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
 258 exit_irq_handled:
 259         mutex_unlock(&info->info_lock);
 260         return IRQ_HANDLED;
 261 exit_irq_none:
 262         WARN_ON_ONCE(1);
 263         return IRQ_NONE;
 264 }
 265
 266 static 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
 297 static 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
 316 static 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
 371 nci_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
 384 probe_exit:
 385         return r;
 386 }
 387
 388 static 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
 398 static struct i2c_device_id nxp_nci_i2c_id_table[] = {
 399         {"nxp-nci_i2c", 0},
 400         {}
 401 };
 402 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 403
 404 static const struct of_device_id of_nxp_nci_i2c_match[] = {
 405         { .compatible = "nxp,nxp-nci-i2c", },
 406         {},
 407 };
 408 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 409
 410 #ifdef CONFIG_ACPI
 411 static struct acpi_device_id acpi_id[] = {
 412         { "NXP7471" },
 413         { },
 414 };
 415 MODULE_DEVICE_TABLE(acpi, acpi_id);
 416 #endif
 417
 418 static 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
 430 module_i2c_driver(nxp_nci_i2c_driver);
 431
 432 MODULE_LICENSE("GPL");
 433 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 434 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
 435 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");