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/module.h>
  33 #include <linux/nfc.h>
  34 #include <linux/gpio/consumer.h>
  35 #include <linux/of_gpio.h>
  36 #include <linux/of_irq.h>
  37 #include <linux/platform_data/nxp-nci.h>
  38 #include <asm/unaligned.h>
  39
  40 #include <net/nfc/nfc.h>
  41
  42 #include "nxp-nci.h"
  43
  44 #define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c"
  45
  46 #define NXP_NCI_I2C_MAX_PAYLOAD 32
  47
  48 struct nxp_nci_i2c_phy {
  49         struct i2c_client *i2c_dev;
  50         struct nci_dev *ndev;
  51
  52         unsigned int gpio_en;
  53         unsigned int gpio_fw;
  54
  55         int hard_fault; /*
  56                          * < 0 if hardware error occurred (e.g. i2c err)
  57                          * and prevents normal operation.
  58                          */
  59 };
  60
  61 static int nxp_nci_i2c_set_mode(void *phy_id,
  62                                     enum nxp_nci_mode mode)
  63 {
  64         struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
  65
  66         gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
  67         gpio_set_value(phy->gpio_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
  68         usleep_range(10000, 15000);
  69
  70         if (mode == NXP_NCI_MODE_COLD)
  71                 phy->hard_fault = 0;
  72
  73         return 0;
  74 }
  75
  76 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
  77 {
  78         int r;
  79         struct nxp_nci_i2c_phy *phy = phy_id;
  80         struct i2c_client *client = phy->i2c_dev;
  81
  82         if (phy->hard_fault != 0)
  83                 return phy->hard_fault;
  84
  85         r = i2c_master_send(client, skb->data, skb->len);
  86         if (r < 0) {
  87                 /* Retry, chip was in standby */
  88                 msleep(110);
  89                 r = i2c_master_send(client, skb->data, skb->len);
  90         }
  91
  92         if (r < 0) {
  93                 nfc_err(&client->dev, "Error %d on I2C send\n", r);
  94         } else if (r != skb->len) {
  95                 nfc_err(&client->dev,
  96                         "Invalid length sent: %u (expected %u)\n",
  97                         r, skb->len);
  98                 r = -EREMOTEIO;
  99         } else {
 100                 /* Success but return 0 and not number of bytes */
 101                 r = 0;
 102         }
 103
 104         return r;
 105 }
 106
 107 static const struct nxp_nci_phy_ops i2c_phy_ops = {
 108         .set_mode = nxp_nci_i2c_set_mode,
 109         .write = nxp_nci_i2c_write,
 110 };
 111
 112 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
 113                                struct sk_buff **skb)
 114 {
 115         struct i2c_client *client = phy->i2c_dev;
 116         u16 header;
 117         size_t frame_len;
 118         int r;
 119
 120         r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
 121         if (r < 0) {
 122                 goto fw_read_exit;
 123         } else if (r != NXP_NCI_FW_HDR_LEN) {
 124                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 125                 r = -EBADMSG;
 126                 goto fw_read_exit;
 127         }
 128
 129         frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) +
 130                     NXP_NCI_FW_CRC_LEN;
 131
 132         *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
 133         if (*skb == NULL) {
 134                 r = -ENOMEM;
 135                 goto fw_read_exit;
 136         }
 137
 138         skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN);
 139
 140         r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
 141         if (r != frame_len) {
 142                 nfc_err(&client->dev,
 143                         "Invalid frame length: %u (expected %zu)\n",
 144                         r, frame_len);
 145                 r = -EBADMSG;
 146                 goto fw_read_exit_free_skb;
 147         }
 148
 149         return 0;
 150
 151 fw_read_exit_free_skb:
 152         kfree_skb(*skb);
 153 fw_read_exit:
 154         return r;
 155 }
 156
 157 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
 158                                 struct sk_buff **skb)
 159 {
 160         struct nci_ctrl_hdr header; /* May actually be a data header */
 161         struct i2c_client *client = phy->i2c_dev;
 162         int r;
 163
 164         r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
 165         if (r < 0) {
 166                 goto nci_read_exit;
 167         } else if (r != NCI_CTRL_HDR_SIZE) {
 168                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 169                 r = -EBADMSG;
 170                 goto nci_read_exit;
 171         }
 172
 173         *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
 174         if (*skb == NULL) {
 175                 r = -ENOMEM;
 176                 goto nci_read_exit;
 177         }
 178
 179         skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
 180
 181         r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
 182         if (r != header.plen) {
 183                 nfc_err(&client->dev,
 184                         "Invalid frame payload length: %u (expected %u)\n",
 185                         r, header.plen);
 186                 r = -EBADMSG;
 187                 goto nci_read_exit_free_skb;
 188         }
 189
 190         return 0;
 191
 192 nci_read_exit_free_skb:
 193         kfree_skb(*skb);
 194 nci_read_exit:
 195         return r;
 196 }
 197
 198 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
 199 {
 200         struct nxp_nci_i2c_phy *phy = phy_id;
 201         struct i2c_client *client;
 202         struct nxp_nci_info *info;
 203
 204         struct sk_buff *skb = NULL;
 205         int r = 0;
 206
 207         if (!phy || !phy->ndev)
 208                 goto exit_irq_none;
 209
 210         client = phy->i2c_dev;
 211
 212         if (!client || irq != client->irq)
 213                 goto exit_irq_none;
 214
 215         info = nci_get_drvdata(phy->ndev);
 216
 217         if (!info)
 218                 goto exit_irq_none;
 219
 220         mutex_lock(&info->info_lock);
 221
 222         if (phy->hard_fault != 0)
 223                 goto exit_irq_handled;
 224
 225         switch (info->mode) {
 226         case NXP_NCI_MODE_NCI:
 227                 r = nxp_nci_i2c_nci_read(phy, &skb);
 228                 break;
 229         case NXP_NCI_MODE_FW:
 230                 r = nxp_nci_i2c_fw_read(phy, &skb);
 231                 break;
 232         case NXP_NCI_MODE_COLD:
 233                 r = -EREMOTEIO;
 234                 break;
 235         }
 236
 237         if (r == -EREMOTEIO) {
 238                 phy->hard_fault = r;
 239                 skb = NULL;
 240         } else if (r < 0) {
 241                 nfc_err(&client->dev, "Read failed with error %d\n", r);
 242                 goto exit_irq_handled;
 243         }
 244
 245         switch (info->mode) {
 246         case NXP_NCI_MODE_NCI:
 247                 nci_recv_frame(phy->ndev, skb);
 248                 break;
 249         case NXP_NCI_MODE_FW:
 250                 nxp_nci_fw_recv_frame(phy->ndev, skb);
 251                 break;
 252         case NXP_NCI_MODE_COLD:
 253                 break;
 254         }
 255
 256 exit_irq_handled:
 257         mutex_unlock(&info->info_lock);
 258         return IRQ_HANDLED;
 259 exit_irq_none:
 260         WARN_ON_ONCE(1);
 261         return IRQ_NONE;
 262 }
 263
 264 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
 265 {
 266         struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 267         struct device_node *pp;
 268         int r;
 269
 270         pp = client->dev.of_node;
 271         if (!pp)
 272                 return -ENODEV;
 273
 274         r = of_get_named_gpio(pp, "enable-gpios", 0);
 275         if (r == -EPROBE_DEFER)
 276                 r = of_get_named_gpio(pp, "enable-gpios", 0);
 277         if (r < 0) {
 278                 nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);
 279                 return r;
 280         }
 281         phy->gpio_en = r;
 282
 283         r = of_get_named_gpio(pp, "firmware-gpios", 0);
 284         if (r == -EPROBE_DEFER)
 285                 r = of_get_named_gpio(pp, "firmware-gpios", 0);
 286         if (r < 0) {
 287                 nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);
 288                 return r;
 289         }
 290         phy->gpio_fw = r;
 291
 292         return 0;
 293 }
 294
 295 static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy)
 296 {
 297         struct i2c_client *client = phy->i2c_dev;
 298         struct gpio_desc *gpiod_en, *gpiod_fw;
 299
 300         gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW);
 301         gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW);
 302
 303         if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw)) {
 304                 nfc_err(&client->dev, "No GPIOs\n");
 305                 return -EINVAL;
 306         }
 307
 308         phy->gpio_en = desc_to_gpio(gpiod_en);
 309         phy->gpio_fw = desc_to_gpio(gpiod_fw);
 310
 311         return 0;
 312 }
 313
 314 static int nxp_nci_i2c_probe(struct i2c_client *client,
 315                             const struct i2c_device_id *id)
 316 {
 317         struct nxp_nci_i2c_phy *phy;
 318         struct nxp_nci_nfc_platform_data *pdata;
 319         int r;
 320
 321         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 322                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 323                 r = -ENODEV;
 324                 goto probe_exit;
 325         }
 326
 327         phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
 328                            GFP_KERNEL);
 329         if (!phy) {
 330                 r = -ENOMEM;
 331                 goto probe_exit;
 332         }
 333
 334         phy->i2c_dev = client;
 335         i2c_set_clientdata(client, phy);
 336
 337         pdata = client->dev.platform_data;
 338
 339         if (!pdata && client->dev.of_node) {
 340                 r = nxp_nci_i2c_parse_devtree(client);
 341                 if (r < 0) {
 342                         nfc_err(&client->dev, "Failed to get DT data\n");
 343                         goto probe_exit;
 344                 }
 345         } else if (pdata) {
 346                 phy->gpio_en = pdata->gpio_en;
 347                 phy->gpio_fw = pdata->gpio_fw;
 348         } else if (ACPI_HANDLE(&client->dev)) {
 349                 r = nxp_nci_i2c_acpi_config(phy);
 350                 if (r < 0)
 351                         goto probe_exit;
 352                 goto nci_probe;
 353         } else {
 354                 nfc_err(&client->dev, "No platform data\n");
 355                 r = -EINVAL;
 356                 goto probe_exit;
 357         }
 358
 359         r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
 360                                   GPIOF_OUT_INIT_LOW, "nxp_nci_en");
 361         if (r < 0)
 362                 goto probe_exit;
 363
 364         r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,
 365                                   GPIOF_OUT_INIT_LOW, "nxp_nci_fw");
 366         if (r < 0)
 367                 goto probe_exit;
 368
 369 nci_probe:
 370         r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
 371                           NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
 372         if (r < 0)
 373                 goto probe_exit;
 374
 375         r = request_threaded_irq(client->irq, NULL,
 376                                  nxp_nci_i2c_irq_thread_fn,
 377                                  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 378                                  NXP_NCI_I2C_DRIVER_NAME, phy);
 379         if (r < 0)
 380                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 381
 382 probe_exit:
 383         return r;
 384 }
 385
 386 static int nxp_nci_i2c_remove(struct i2c_client *client)
 387 {
 388         struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 389
 390         nxp_nci_remove(phy->ndev);
 391         free_irq(client->irq, phy);
 392
 393         return 0;
 394 }
 395
 396 static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
 397         {"nxp-nci_i2c", 0},
 398         {}
 399 };
 400 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 401
 402 static const struct of_device_id of_nxp_nci_i2c_match[] = {
 403         { .compatible = "nxp,nxp-nci-i2c", },
 404         {},
 405 };
 406 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 407
 408 #ifdef CONFIG_ACPI
 409 static struct acpi_device_id acpi_id[] = {
 410         { "NXP7471" },
 411         { },
 412 };
 413 MODULE_DEVICE_TABLE(acpi, acpi_id);
 414 #endif
 415
 416 static struct i2c_driver nxp_nci_i2c_driver = {
 417         .driver = {
 418                    .name = NXP_NCI_I2C_DRIVER_NAME,
 419                    .acpi_match_table = ACPI_PTR(acpi_id),
 420                    .of_match_table = of_match_ptr(of_nxp_nci_i2c_match),
 421                   },
 422         .probe = nxp_nci_i2c_probe,
 423         .id_table = nxp_nci_i2c_id_table,
 424         .remove = nxp_nci_i2c_remove,
 425 };
 426
 427 module_i2c_driver(nxp_nci_i2c_driver);
 428
 429 MODULE_LICENSE("GPL");
 430 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 431 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
 432 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");