linux/drivers/nfc/pn533/i2c.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Driver for NXP PN533 NFC Chip - I2C transport layer
   4 *
   5 * Copyright (C) 2011 Instituto Nokia de Tecnologia
   6 * Copyright (C) 2012-2013 Tieto Poland
   7 * Copyright (C) 2016 HALE electronic
   8 */
   9
  10#include <linux/device.h>
  11#include <linux/kernel.h>
  12#include <linux/module.h>
  13#include <linux/slab.h>
  14#include <linux/i2c.h>
  15#include <linux/nfc.h>
  16#include <linux/netdevice.h>
  17#include <linux/interrupt.h>
  18#include <net/nfc/nfc.h>
  19#include "pn533.h"
  20
  21#define VERSION "0.1"
  22
  23#define PN533_I2C_DRIVER_NAME "pn533_i2c"
  24
  25struct pn533_i2c_phy {
  26        struct i2c_client *i2c_dev;
  27        struct pn533 *priv;
  28
  29        bool aborted;
  30
  31        int hard_fault;         /*
  32                                 * < 0 if hardware error occurred (e.g. i2c err)
  33                                 * and prevents normal operation.
  34                                 */
  35};
  36
  37static int pn533_i2c_send_ack(struct pn533 *dev, gfp_t flags)
  38{
  39        struct pn533_i2c_phy *phy = dev->phy;
  40        struct i2c_client *client = phy->i2c_dev;
  41        static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
  42        /* spec 6.2.1.3:  Preamble, SoPC (2), ACK Code (2), Postamble */
  43
  44        return i2c_master_send(client, ack, 6);
  45}
  46
  47static int pn533_i2c_send_frame(struct pn533 *dev,
  48                                struct sk_buff *out)
  49{
  50        struct pn533_i2c_phy *phy = dev->phy;
  51        struct i2c_client *client = phy->i2c_dev;
  52        int rc;
  53
  54        if (phy->hard_fault != 0)
  55                return phy->hard_fault;
  56
  57        if (phy->priv == NULL)
  58                phy->priv = dev;
  59
  60        phy->aborted = false;
  61
  62        print_hex_dump_debug("PN533_i2c TX: ", DUMP_PREFIX_NONE, 16, 1,
  63                             out->data, out->len, false);
  64
  65        rc = i2c_master_send(client, out->data, out->len);
  66
  67        if (rc == -EREMOTEIO) { /* Retry, chip was in power down */
  68                usleep_range(6000, 10000);
  69                rc = i2c_master_send(client, out->data, out->len);
  70        }
  71
  72        if (rc >= 0) {
  73                if (rc != out->len)
  74                        rc = -EREMOTEIO;
  75                else
  76                        rc = 0;
  77        }
  78
  79        return rc;
  80}
  81
  82static void pn533_i2c_abort_cmd(struct pn533 *dev, gfp_t flags)
  83{
  84        struct pn533_i2c_phy *phy = dev->phy;
  85
  86        phy->aborted = true;
  87
  88        /* An ack will cancel the last issued command */
  89        pn533_i2c_send_ack(dev, flags);
  90
  91        /* schedule cmd_complete_work to finish current command execution */
  92        pn533_recv_frame(phy->priv, NULL, -ENOENT);
  93}
  94
  95static int pn533_i2c_read(struct pn533_i2c_phy *phy, struct sk_buff **skb)
  96{
  97        struct i2c_client *client = phy->i2c_dev;
  98        int len = PN533_EXT_FRAME_HEADER_LEN +
  99                  PN533_STD_FRAME_MAX_PAYLOAD_LEN +
 100                  PN533_STD_FRAME_TAIL_LEN + 1;
 101        int r;
 102
 103        *skb = alloc_skb(len, GFP_KERNEL);
 104        if (*skb == NULL)
 105                return -ENOMEM;
 106
 107        r = i2c_master_recv(client, skb_put(*skb, len), len);
 108        if (r != len) {
 109                nfc_err(&client->dev, "cannot read. r=%d len=%d\n", r, len);
 110                kfree_skb(*skb);
 111                return -EREMOTEIO;
 112        }
 113
 114        if (!((*skb)->data[0] & 0x01)) {
 115                nfc_err(&client->dev, "READY flag not set");
 116                kfree_skb(*skb);
 117                return -EBUSY;
 118        }
 119
 120        /* remove READY byte */
 121        skb_pull(*skb, 1);
 122        /* trim to frame size */
 123        skb_trim(*skb, phy->priv->ops->rx_frame_size((*skb)->data));
 124
 125        return 0;
 126}
 127
 128static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
 129{
 130        struct pn533_i2c_phy *phy = data;
 131        struct i2c_client *client;
 132        struct sk_buff *skb = NULL;
 133        int r;
 134
 135        if (!phy || irq != phy->i2c_dev->irq) {
 136                WARN_ON_ONCE(1);
 137                return IRQ_NONE;
 138        }
 139
 140        client = phy->i2c_dev;
 141        dev_dbg(&client->dev, "IRQ\n");
 142
 143        if (phy->hard_fault != 0)
 144                return IRQ_HANDLED;
 145
 146        r = pn533_i2c_read(phy, &skb);
 147        if (r == -EREMOTEIO) {
 148                phy->hard_fault = r;
 149
 150                pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
 151
 152                return IRQ_HANDLED;
 153        } else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
 154                return IRQ_HANDLED;
 155        }
 156
 157        if (!phy->aborted)
 158                pn533_recv_frame(phy->priv, skb, 0);
 159
 160        return IRQ_HANDLED;
 161}
 162
 163static struct pn533_phy_ops i2c_phy_ops = {
 164        .send_frame = pn533_i2c_send_frame,
 165        .send_ack = pn533_i2c_send_ack,
 166        .abort_cmd = pn533_i2c_abort_cmd,
 167};
 168
 169
 170static int pn533_i2c_probe(struct i2c_client *client,
 171                               const struct i2c_device_id *id)
 172{
 173        struct pn533_i2c_phy *phy;
 174        struct pn533 *priv;
 175        int r = 0;
 176
 177        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 178                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 179                return -ENODEV;
 180        }
 181
 182        phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
 183                           GFP_KERNEL);
 184        if (!phy)
 185                return -ENOMEM;
 186
 187        phy->i2c_dev = client;
 188        i2c_set_clientdata(client, phy);
 189
 190        priv = pn53x_common_init(PN533_DEVICE_PN532,
 191                                PN533_PROTO_REQ_ACK_RESP,
 192                                phy, &i2c_phy_ops, NULL,
 193                                &phy->i2c_dev->dev);
 194
 195        if (IS_ERR(priv))
 196                return PTR_ERR(priv);
 197
 198        phy->priv = priv;
 199        r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
 200        if (r)
 201                goto nfc_alloc_err;
 202
 203        r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
 204                                IRQF_TRIGGER_FALLING |
 205                                IRQF_SHARED | IRQF_ONESHOT,
 206                                PN533_I2C_DRIVER_NAME, phy);
 207        if (r < 0) {
 208                nfc_err(&client->dev, "Unable to register IRQ handler\n");
 209                goto irq_rqst_err;
 210        }
 211
 212        r = pn533_finalize_setup(priv);
 213        if (r)
 214                goto fn_setup_err;
 215
 216        r = nfc_register_device(priv->nfc_dev);
 217        if (r)
 218                goto fn_setup_err;
 219
 220        return r;
 221
 222fn_setup_err:
 223        free_irq(client->irq, phy);
 224
 225irq_rqst_err:
 226        nfc_free_device(priv->nfc_dev);
 227
 228nfc_alloc_err:
 229        pn53x_common_clean(phy->priv);
 230
 231        return r;
 232}
 233
 234static int pn533_i2c_remove(struct i2c_client *client)
 235{
 236        struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
 237
 238        free_irq(client->irq, phy);
 239
 240        pn53x_unregister_nfc(phy->priv);
 241        pn53x_common_clean(phy->priv);
 242
 243        return 0;
 244}
 245
 246static const struct of_device_id of_pn533_i2c_match[] __maybe_unused = {
 247        { .compatible = "nxp,pn532", },
 248        /*
 249         * NOTE: The use of the compatibles with the trailing "...-i2c" is
 250         * deprecated and will be removed.
 251         */
 252        { .compatible = "nxp,pn533-i2c", },
 253        { .compatible = "nxp,pn532-i2c", },
 254        {},
 255};
 256MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
 257
 258static const struct i2c_device_id pn533_i2c_id_table[] = {
 259        { PN533_I2C_DRIVER_NAME, 0 },
 260        {}
 261};
 262MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
 263
 264static struct i2c_driver pn533_i2c_driver = {
 265        .driver = {
 266                   .name = PN533_I2C_DRIVER_NAME,
 267                   .of_match_table = of_match_ptr(of_pn533_i2c_match),
 268                  },
 269        .probe = pn533_i2c_probe,
 270        .id_table = pn533_i2c_id_table,
 271        .remove = pn533_i2c_remove,
 272};
 273
 274module_i2c_driver(pn533_i2c_driver);
 275
 276MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
 277MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
 278MODULE_VERSION(VERSION);
 279MODULE_LICENSE("GPL");
 280