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 <asm/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         u16 header;
 101         size_t frame_len;
 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 != frame_len) {
 126                 nfc_err(&client->dev,
 127                         "Invalid frame length: %u (expected %zu)\n",
 128                         r, frame_len);
 129                 r = -EBADMSG;
 130                 goto fw_read_exit_free_skb;
 131         }
 132
 133         return 0;
 134
 135 fw_read_exit_free_skb:
 136         kfree_skb(*skb);
 137 fw_read_exit:
 138         return r;
 139 }
 140
 141 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
 142                                 struct sk_buff **skb)
 143 {
 144         struct nci_ctrl_hdr header; /* May actually be a data header */
 145         struct i2c_client *client = phy->i2c_dev;
 146         int r;
 147
 148         r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
 149         if (r < 0) {
 150                 goto nci_read_exit;
 151         } else if (r != NCI_CTRL_HDR_SIZE) {
 152                 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
 153                 r = -EBADMSG;
 154                 goto nci_read_exit;
 155         }
 156
 157         *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
 158         if (*skb == NULL) {
 159                 r = -ENOMEM;
 160                 goto nci_read_exit;
 161         }
 162
 163         skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
 164
 165         r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
 166         if (r != header.plen) {
 167                 nfc_err(&client->dev,
 168                         "Invalid frame payload length: %u (expected %u)\n",
 169                         r, header.plen);
 170                 r = -EBADMSG;
 171                 goto nci_read_exit_free_skb;
 172         }
 173
 174         return 0;
 175
 176 nci_read_exit_free_skb:
 177         kfree_skb(*skb);
 178 nci_read_exit:
 179         return r;
 180 }
 181
 182 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
 183 {
 184         struct nxp_nci_i2c_phy *phy = phy_id;
 185         struct i2c_client *client;
 186         struct nxp_nci_info *info;
 187
 188         struct sk_buff *skb = NULL;
 189         int r = 0;
 190
 191         if (!phy || !phy->ndev)
 192                 goto exit_irq_none;
 193
 194         client = phy->i2c_dev;
 195
 196         if (!client || irq != client->irq)
 197                 goto exit_irq_none;
 198
 199         info = nci_get_drvdata(phy->ndev);
 200
 201         if (!info)
 202                 goto exit_irq_none;
 203
 204         mutex_lock(&info->info_lock);
 205
 206         if (phy->hard_fault != 0)
 207                 goto exit_irq_handled;
 208
 209         switch (info->mode) {
 210         case NXP_NCI_MODE_NCI:
 211                 r = nxp_nci_i2c_nci_read(phy, &skb);
 212                 break;
 213         case NXP_NCI_MODE_FW:
 214                 r = nxp_nci_i2c_fw_read(phy, &skb);
 215                 break;
 216         case NXP_NCI_MODE_COLD:
 217                 r = -EREMOTEIO;
 218                 break;
 219         }
 220
 221         if (r == -EREMOTEIO) {
 222                 phy->hard_fault = r;
 223                 if (info->mode == NXP_NCI_MODE_FW)
 224                         nxp_nci_fw_recv_frame(phy->ndev, NULL);
 225         }
 226         if (r < 0) {
 227                 nfc_err(&client->dev, "Read failed with error %d\n", r);
 228                 goto exit_irq_handled;
 229         }
 230
 231         switch (info->mode) {
 232         case NXP_NCI_MODE_NCI:
 233                 nci_recv_frame(phy->ndev, skb);
 234                 break;
 235         case NXP_NCI_MODE_FW:
 236                 nxp_nci_fw_recv_frame(phy->ndev, skb);
 237                 break;
 238         case NXP_NCI_MODE_COLD:
 239                 break;
 240         }
 241
 242 exit_irq_handled:
 243         mutex_unlock(&info->info_lock);
 244         return IRQ_HANDLED;
 245 exit_irq_none:
 246         WARN_ON_ONCE(1);
 247         return IRQ_NONE;
 248 }
 249
 250 static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
 251 static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
 252
 253 static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
 254         { "enable-gpios", &enable_gpios, 1 },
 255         { "firmware-gpios", &firmware_gpios, 1 },
 256         { }
 257 };
 258
 259 static int nxp_nci_i2c_probe(struct i2c_client *client,
 260                             const struct i2c_device_id *id)
 261 {
 262         struct device *dev = &client->dev;
 263         struct nxp_nci_i2c_phy *phy;
 264         int r;
 265
 266         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 267                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 268                 return -ENODEV;
 269         }
 270
 271         phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
 272                            GFP_KERNEL);
 273         if (!phy)
 274                 return -ENOMEM;
 275
 276         phy->i2c_dev = client;
 277         i2c_set_clientdata(client, phy);
 278
 279         r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios);
 280         if (r)
 281                 dev_dbg(dev, "Unable to add GPIO mapping table\n");
 282
 283         phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
 284         if (IS_ERR(phy->gpiod_en)) {
 285                 nfc_err(dev, "Failed to get EN gpio\n");
 286                 return PTR_ERR(phy->gpiod_en);
 287         }
 288
 289         phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW);
 290         if (IS_ERR(phy->gpiod_fw)) {
 291                 nfc_err(dev, "Failed to get FW gpio\n");
 292                 return PTR_ERR(phy->gpiod_fw);
 293         }
 294
 295         r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
 296                           NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
 297         if (r < 0)
 298                 return r;
 299
 300         r = request_threaded_irq(client->irq, NULL,
 301                                  nxp_nci_i2c_irq_thread_fn,
 302                                  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 303                                  NXP_NCI_I2C_DRIVER_NAME, phy);
 304         if (r < 0)
 305                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 306
 307         return r;
 308 }
 309
 310 static int nxp_nci_i2c_remove(struct i2c_client *client)
 311 {
 312         struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
 313
 314         nxp_nci_remove(phy->ndev);
 315         free_irq(client->irq, phy);
 316
 317         return 0;
 318 }
 319
 320 static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
 321         {"nxp-nci_i2c", 0},
 322         {}
 323 };
 324 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 325
 326 static const struct of_device_id of_nxp_nci_i2c_match[] = {
 327         { .compatible = "nxp,nxp-nci-i2c", },
 328         {}
 329 };
 330 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 331
 332 #ifdef CONFIG_ACPI
 333 static const struct acpi_device_id acpi_id[] = {
 334         { "NXP1001" },
 335         { "NXP7471" },
 336         { }
 337 };
 338 MODULE_DEVICE_TABLE(acpi, acpi_id);
 339 #endif
 340
 341 static struct i2c_driver nxp_nci_i2c_driver = {
 342         .driver = {
 343                    .name = NXP_NCI_I2C_DRIVER_NAME,
 344                    .acpi_match_table = ACPI_PTR(acpi_id),
 345                    .of_match_table = of_nxp_nci_i2c_match,
 346                   },
 347         .probe = nxp_nci_i2c_probe,
 348         .id_table = nxp_nci_i2c_id_table,
 349         .remove = nxp_nci_i2c_remove,
 350 };
 351
 352 module_i2c_driver(nxp_nci_i2c_driver);
 353
 354 MODULE_LICENSE("GPL");
 355 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 356 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
 357 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");