drivers/nfc/nxp-nci/i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * I2C link layer for the NXP NCI driver
   4  *
   5  * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
   6  * Copyright (C) 2012-2015  Intel Corporation. All rights reserved.
   7  *
   8  * Authors: Clément Perrochaud <clement.perrochaud@nxp.com>
   9  * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>
  10  *
  11  * Derived from PN544 device driver:
  12  * Copyright (C) 2012  Intel Corporation. All rights reserved.
  13  */
  14
  15 #include <linux/acpi.h>
  16 #include <linux/delay.h>
  17 #include <linux/i2c.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/module.h>
  20 #include <linux/nfc.h>
  21 #include <linux/gpio/consumer.h>
  22 #include <linux/unaligned.h>
  23
  24 #include <net/nfc/nfc.h>
  25
  26 #include "nxp-nci.h"
  27
  28 #define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c"
  29
  30 #define NXP_NCI_I2C_MAX_PAYLOAD 32
  31
  32 struct nxp_nci_i2c_phy {
  33         struct i2c_client *i2c_dev;
  34         struct nci_dev *ndev;
  35
  36         struct gpio_desc *gpiod_en;
  37         struct gpio_desc *gpiod_fw;
  38
  39         int hard_fault; /*
  40                          * < 0 if hardware error occurred (e.g. i2c err)
  41                          * and prevents normal operation.
  42                          */
  43 };
  44
  45 static int nxp_nci_i2c_set_mode(void *phy_id,
  46                                     enum nxp_nci_mode mode)
  47 {
  48         struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
  49
  50         gpiod_set_value(phy->gpiod_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
  51         gpiod_set_value(phy->gpiod_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
  52         usleep_range(10000, 15000);
  53
  54         if (mode == NXP_NCI_MODE_COLD)
  55                 phy->hard_fault = 0;
  56
  57         return 0;
  58 }
  59
  60 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
  61 {
  62         int r;
  63         struct nxp_nci_i2c_phy *phy = phy_id;
  64         struct i2c_client *client = phy->i2c_dev;
  65
  66         if (phy->hard_fault != 0)
  67                 return phy->hard_fault;
  68
  69         r = i2c_master_send(client, skb->data, skb->len);
  70         if (r < 0) {
  71                 /* Retry, chip was in standby */
  72                 msleep(110);
  73                 r = i2c_master_send(client, skb->data, skb->len);
  74         }
  75
  76         if (r < 0) {
  77                 nfc_err(&client->dev, "Error %d on I2C send\n", r);
  78         } else if (r != skb->len) {
  79                 nfc_err(&client->dev,
  80                         "Invalid length sent: %u (expected %u)\n",
  81                         r, skb->len);
  82                 r = -EREMOTEIO;
  83         } else {
  84                 /* Success but return 0 and not number of bytes */
  85                 r = 0;
  86         }
  87
  88         return r;
  89 }
  90
  91 static const struct nxp_nci_phy_ops i2c_phy_ops = {
  92         .set_mode = nxp_nci_i2c_set_mode,
  93         .write = nxp_nci_i2c_write,
  94 };
  95
  96 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
  97                                struct sk_buff **skb)
  98 {
  99         struct i2c_client *client = phy->i2c_dev;
 100         size_t frame_len;
 101         __be16 header;
 102         int r;
 103
 104         r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
 105         if (r < 0) {
 106                 goto fw_read_exit;
 107         } else if (r != NXP_NCI_FW_HDR_LEN) {
 108                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 109                 r = -EBADMSG;
 110                 goto fw_read_exit;
 111         }
 112
 113         frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) +
 114                     NXP_NCI_FW_CRC_LEN;
 115
 116         *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
 117         if (*skb == NULL) {
 118                 r = -ENOMEM;
 119                 goto fw_read_exit;
 120         }
 121
 122         skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN);
 123
 124         r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
 125         if (r < 0) {
 126                 goto fw_read_exit_free_skb;
 127         } else if (r != frame_len) {
 128                 nfc_err(&client->dev,
 129                         "Invalid frame length: %u (expected %zu)\n",
 130                         r, frame_len);
 131                 r = -EBADMSG;
 132                 goto fw_read_exit_free_skb;
 133         }
 134
 135         return 0;
 136
 137 fw_read_exit_free_skb:
 138         kfree_skb(*skb);
 139 fw_read_exit:
 140         return r;
 141 }
 142
 143 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
 144                                 struct sk_buff **skb)
 145 {
 146         struct nci_ctrl_hdr header; /* May actually be a data header */
 147         struct i2c_client *client = phy->i2c_dev;
 148         int r;
 149
 150         r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
 151         if (r < 0) {
 152                 goto nci_read_exit;
 153         } else if (r != NCI_CTRL_HDR_SIZE) {
 154                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 155                 r = -EBADMSG;
 156                 goto nci_read_exit;
 157         }
 158
 159         *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
 160         if (*skb == NULL) {
 161                 r = -ENOMEM;
 162                 goto nci_read_exit;
 163         }
 164
 165         skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
 166
 167         if (!header.plen)
 168                 return 0;
 169
 170         r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
 171         if (r < 0) {
 172                 goto nci_read_exit_free_skb;
 173         } else if (r != header.plen) {
 174                 nfc_err(&client->dev,
 175                         "Invalid frame payload length: %u (expected %u)\n",
 176                         r, header.plen);
 177                 r = -EBADMSG;
 178                 goto nci_read_exit_free_skb;
 179         }
 180
 181         return 0;
 182
 183 nci_read_exit_free_skb:
 184         kfree_skb(*skb);
 185 nci_read_exit:
 186         return r;
 187 }
 188
 189 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
 190 {
 191         struct nxp_nci_i2c_phy *phy = phy_id;
 192         struct i2c_client *client;
 193         struct nxp_nci_info *info;
 194
 195         struct sk_buff *skb = NULL;
 196         int r = 0;
 197
 198         if (!phy || !phy->ndev)
 199                 goto exit_irq_none;
 200
 201         client = phy->i2c_dev;
 202
 203         if (!client || irq != client->irq)
 204                 goto exit_irq_none;
 205
 206         info = nci_get_drvdata(phy->ndev);
 207
 208         if (!info)
 209                 goto exit_irq_none;
 210
 211         mutex_lock(&info->info_lock);
 212
 213         if (phy->hard_fault != 0)
 214                 goto exit_irq_handled;
 215
 216         switch (info->mode) {
 217         case NXP_NCI_MODE_NCI:
 218                 r = nxp_nci_i2c_nci_read(phy, &skb);
 219                 break;
 220         case NXP_NCI_MODE_FW:
 221                 r = nxp_nci_i2c_fw_read(phy, &skb);
 222                 break;
 223         case NXP_NCI_MODE_COLD:
 224                 r = -EREMOTEIO;
 225                 break;
 226         }
 227
 228         if (r == -EREMOTEIO) {
 229                 phy->hard_fault = r;
 230                 if (info->mode == NXP_NCI_MODE_FW)
 231                         nxp_nci_fw_recv_frame(phy->ndev, NULL);
 232         }
 233         if (r < 0) {
 234                 nfc_err(&client->dev, "Read failed with error %d\n", r);
 235                 goto exit_irq_handled;
 236         }
 237
 238         switch (info->mode) {
 239         case NXP_NCI_MODE_NCI:
 240                 nci_recv_frame(phy->ndev, skb);
 241                 break;
 242         case NXP_NCI_MODE_FW:
 243                 nxp_nci_fw_recv_frame(phy->ndev, skb);
 244                 break;
 245         case NXP_NCI_MODE_COLD:
 246                 break;
 247         }
 248
 249 exit_irq_handled:
 250         mutex_unlock(&info->info_lock);
 251         return IRQ_HANDLED;
 252 exit_irq_none:
 253         WARN_ON_ONCE(1);
 254         return IRQ_NONE;
 255 }
 256
 257 static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
 258 static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
 259
 260 static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
 261         { "enable-gpios", &enable_gpios, 1 },
 262         { "firmware-gpios", &firmware_gpios, 1 },
 263         { }
 264 };
 265
 266 static int nxp_nci_i2c_probe(struct i2c_client *client)
 267 {
 268         struct device *dev = &client->dev;
 269         struct nxp_nci_i2c_phy *phy;
 270         int r;
 271
 272         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 273                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 274                 return -ENODEV;
 275         }
 276
 277         phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
 278                            GFP_KERNEL);
 279         if (!phy)
 280                 return -ENOMEM;
 281
 282         phy->i2c_dev = client;
 283         i2c_set_clientdata(client, phy);
 284
 285         r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios);
 286         if (r)
 287                 dev_dbg(dev, "Unable to add GPIO mapping table\n");
 288
 289         phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
 290         if (IS_ERR(phy->gpiod_en)) {
 291                 nfc_err(dev, "Failed to get EN gpio\n");
 292                 return PTR_ERR(phy->gpiod_en);
 293         }
 294
 295         phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW);
 296         if (IS_ERR(phy->gpiod_fw)) {
 297                 nfc_err(dev, "Failed to get FW gpio\n");
 298                 return PTR_ERR(phy->gpiod_fw);
 299         }
 300
 301         r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
 302                           NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
 303         if (r < 0)
 304                 return r;
 305
 306         r = request_threaded_irq(client->irq, NULL,
 307                                  nxp_nci_i2c_irq_thread_fn,
 308                                  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 309                                  NXP_NCI_I2C_DRIVER_NAME, phy);
 310         if (r < 0)
 311                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 312
 313         return r;
 314 }
 315
 316 static void nxp_nci_i2c_remove(struct i2c_client *client)
 317 {
 318         struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 319
 320         nxp_nci_remove(phy->ndev);
 321         free_irq(client->irq, phy);
 322 }
 323
 324 static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
 325         { "nxp-nci_i2c" },
 326         {}
 327 };
 328 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 329
 330 static const struct of_device_id of_nxp_nci_i2c_match[] = {
 331         { .compatible = "nxp,nxp-nci-i2c", },
 332         {}
 333 };
 334 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 335
 336 #ifdef CONFIG_ACPI
 337 static const struct acpi_device_id acpi_id[] = {
 338         { "NXP1001" },
 339         { "NXP1002" },
 340         { "NXP7471" },
 341         { }
 342 };
 343 MODULE_DEVICE_TABLE(acpi, acpi_id);
 344 #endif
 345
 346 static struct i2c_driver nxp_nci_i2c_driver = {
 347         .driver = {
 348                    .name = NXP_NCI_I2C_DRIVER_NAME,
 349                    .acpi_match_table = ACPI_PTR(acpi_id),
 350                    .of_match_table = of_nxp_nci_i2c_match,
 351                   },
 352         .probe = nxp_nci_i2c_probe,
 353         .id_table = nxp_nci_i2c_id_table,
 354         .remove = nxp_nci_i2c_remove,
 355 };
 356
 357 module_i2c_driver(nxp_nci_i2c_driver);
 358
 359 MODULE_LICENSE("GPL");
 360 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 361 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
 362 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");