drivers/nfc/pn533/i2c.c

   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
  25 struct 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
  37 static 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
  47 static 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
  82 static 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
  95 static 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
 128 static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
 129 {
 130         struct pn533_i2c_phy *phy = data;
 131         struct sk_buff *skb = NULL;
 132         int r;
 133
 134         if (!phy || irq != phy->i2c_dev->irq) {
 135                 WARN_ON_ONCE(1);
 136                 return IRQ_NONE;
 137         }
 138
 139         if (phy->hard_fault != 0)
 140                 return IRQ_HANDLED;
 141
 142         r = pn533_i2c_read(phy, &skb);
 143         if (r == -EREMOTEIO) {
 144                 phy->hard_fault = r;
 145
 146                 pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
 147
 148                 return IRQ_HANDLED;
 149         } else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
 150                 return IRQ_HANDLED;
 151         }
 152
 153         if (!phy->aborted)
 154                 pn533_recv_frame(phy->priv, skb, 0);
 155
 156         return IRQ_HANDLED;
 157 }
 158
 159 static const struct pn533_phy_ops i2c_phy_ops = {
 160         .send_frame = pn533_i2c_send_frame,
 161         .send_ack = pn533_i2c_send_ack,
 162         .abort_cmd = pn533_i2c_abort_cmd,
 163 };
 164
 165
 166 static int pn533_i2c_probe(struct i2c_client *client)
 167 {
 168         struct pn533_i2c_phy *phy;
 169         struct pn533 *priv;
 170         int r = 0;
 171
 172         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 173                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 174                 return -ENODEV;
 175         }
 176
 177         phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
 178                            GFP_KERNEL);
 179         if (!phy)
 180                 return -ENOMEM;
 181
 182         phy->i2c_dev = client;
 183         i2c_set_clientdata(client, phy);
 184
 185         priv = pn53x_common_init(PN533_DEVICE_PN532,
 186                                 PN533_PROTO_REQ_ACK_RESP,
 187                                 phy, &i2c_phy_ops, NULL,
 188                                 &phy->i2c_dev->dev);
 189
 190         if (IS_ERR(priv))
 191                 return PTR_ERR(priv);
 192
 193         phy->priv = priv;
 194         r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
 195         if (r)
 196                 goto nfc_alloc_err;
 197
 198         r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
 199                                 IRQF_TRIGGER_FALLING |
 200                                 IRQF_SHARED | IRQF_ONESHOT,
 201                                 PN533_I2C_DRIVER_NAME, phy);
 202         if (r < 0) {
 203                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 204                 goto irq_rqst_err;
 205         }
 206
 207         r = pn533_finalize_setup(priv);
 208         if (r)
 209                 goto fn_setup_err;
 210
 211         r = nfc_register_device(priv->nfc_dev);
 212         if (r)
 213                 goto fn_setup_err;
 214
 215         return r;
 216
 217 fn_setup_err:
 218         free_irq(client->irq, phy);
 219
 220 irq_rqst_err:
 221         nfc_free_device(priv->nfc_dev);
 222
 223 nfc_alloc_err:
 224         pn53x_common_clean(phy->priv);
 225
 226         return r;
 227 }
 228
 229 static void pn533_i2c_remove(struct i2c_client *client)
 230 {
 231         struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
 232
 233         free_irq(client->irq, phy);
 234
 235         pn53x_unregister_nfc(phy->priv);
 236         pn53x_common_clean(phy->priv);
 237 }
 238
 239 static const struct of_device_id of_pn533_i2c_match[] __maybe_unused = {
 240         { .compatible = "nxp,pn532", },
 241         /*
 242          * NOTE: The use of the compatibles with the trailing "...-i2c" is
 243          * deprecated and will be removed.
 244          */
 245         { .compatible = "nxp,pn533-i2c", },
 246         { .compatible = "nxp,pn532-i2c", },
 247         {},
 248 };
 249 MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
 250
 251 static const struct i2c_device_id pn533_i2c_id_table[] = {
 252         { PN533_I2C_DRIVER_NAME },
 253         {}
 254 };
 255 MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
 256
 257 static struct i2c_driver pn533_i2c_driver = {
 258         .driver = {
 259                    .name = PN533_I2C_DRIVER_NAME,
 260                    .of_match_table = of_match_ptr(of_pn533_i2c_match),
 261                   },
 262         .probe = pn533_i2c_probe,
 263         .id_table = pn533_i2c_id_table,
 264         .remove = pn533_i2c_remove,
 265 };
 266
 267 module_i2c_driver(pn533_i2c_driver);
 268
 269 MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
 270 MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
 271 MODULE_VERSION(VERSION);
 272 MODULE_LICENSE("GPL");