linux/drivers/nfc/nxp-nci/i2c.c
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   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: Cl\xC3\xA9ment 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
  32struct 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
  45static 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
  60static 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
  91static 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
  96static 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
 135fw_read_exit_free_skb:
 136        kfree_skb(*skb);
 137fw_read_exit:
 138        return r;
 139}
 140
 141static 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
 176nci_read_exit_free_skb:
 177        kfree_skb(*skb);
 178nci_read_exit:
 179        return r;
 180}
 181
 182static 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
 242exit_irq_handled:
 243        mutex_unlock(&info->info_lock);
 244        return IRQ_HANDLED;
 245exit_irq_none:
 246        WARN_ON_ONCE(1);
 247        return IRQ_NONE;
 248}
 249
 250static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
 251static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
 252
 253static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
 254        { "enable-gpios", &enable_gpios, 1 },
 255        { "firmware-gpios", &firmware_gpios, 1 },
 256        { }
 257};
 258
 259static 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
 310static 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
 320static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
 321        {"nxp-nci_i2c", 0},
 322        {}
 323};
 324MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
 325
 326static const struct of_device_id of_nxp_nci_i2c_match[] = {
 327        { .compatible = "nxp,nxp-nci-i2c", },
 328        {}
 329};
 330MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
 331
 332#ifdef CONFIG_ACPI
 333static const struct acpi_device_id acpi_id[] = {
 334        { "NXP1001" },
 335        { "NXP7471" },
 336        { }
 337};
 338MODULE_DEVICE_TABLE(acpi, acpi_id);
 339#endif
 340
 341static 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
 352module_i2c_driver(nxp_nci_i2c_driver);
 353
 354MODULE_LICENSE("GPL");
 355MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
 356MODULE_AUTHOR("Cl\xC3\xA9ment Perrochaud <clement.perrochaud@nxp.com>");
 357MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
 358