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         int rc;
  44
  45         rc = i2c_master_send(client, ack, 6);
  46
  47         return rc;
  48 }
  49
  50 static int pn533_i2c_send_frame(struct pn533 *dev,
  51                                 struct sk_buff *out)
  52 {
  53         struct pn533_i2c_phy *phy = dev->phy;
  54         struct i2c_client *client = phy->i2c_dev;
  55         int rc;
  56
  57         if (phy->hard_fault != 0)
  58                 return phy->hard_fault;
  59
  60         if (phy->priv == NULL)
  61                 phy->priv = dev;
  62
  63         phy->aborted = false;
  64
  65         print_hex_dump_debug("PN533_i2c TX: ", DUMP_PREFIX_NONE, 16, 1,
  66                              out->data, out->len, false);
  67
  68         rc = i2c_master_send(client, out->data, out->len);
  69
  70         if (rc == -EREMOTEIO) { /* Retry, chip was in power down */
  71                 usleep_range(6000, 10000);
  72                 rc = i2c_master_send(client, out->data, out->len);
  73         }
  74
  75         if (rc >= 0) {
  76                 if (rc != out->len)
  77                         rc = -EREMOTEIO;
  78                 else
  79                         rc = 0;
  80         }
  81
  82         return rc;
  83 }
  84
  85 static void pn533_i2c_abort_cmd(struct pn533 *dev, gfp_t flags)
  86 {
  87         struct pn533_i2c_phy *phy = dev->phy;
  88
  89         phy->aborted = true;
  90
  91         /* An ack will cancel the last issued command */
  92         pn533_i2c_send_ack(dev, flags);
  93
  94         /* schedule cmd_complete_work to finish current command execution */
  95         pn533_recv_frame(phy->priv, NULL, -ENOENT);
  96 }
  97
  98 static int pn533_i2c_read(struct pn533_i2c_phy *phy, struct sk_buff **skb)
  99 {
 100         struct i2c_client *client = phy->i2c_dev;
 101         int len = PN533_EXT_FRAME_HEADER_LEN +
 102                   PN533_STD_FRAME_MAX_PAYLOAD_LEN +
 103                   PN533_STD_FRAME_TAIL_LEN + 1;
 104         int r;
 105
 106         *skb = alloc_skb(len, GFP_KERNEL);
 107         if (*skb == NULL)
 108                 return -ENOMEM;
 109
 110         r = i2c_master_recv(client, skb_put(*skb, len), len);
 111         if (r != len) {
 112                 nfc_err(&client->dev, "cannot read. r=%d len=%d\n", r, len);
 113                 kfree_skb(*skb);
 114                 return -EREMOTEIO;
 115         }
 116
 117         if (!((*skb)->data[0] & 0x01)) {
 118                 nfc_err(&client->dev, "READY flag not set");
 119                 kfree_skb(*skb);
 120                 return -EBUSY;
 121         }
 122
 123         /* remove READY byte */
 124         skb_pull(*skb, 1);
 125         /* trim to frame size */
 126         skb_trim(*skb, phy->priv->ops->rx_frame_size((*skb)->data));
 127
 128         return 0;
 129 }
 130
 131 static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
 132 {
 133         struct pn533_i2c_phy *phy = data;
 134         struct i2c_client *client;
 135         struct sk_buff *skb = NULL;
 136         int r;
 137
 138         if (!phy || irq != phy->i2c_dev->irq) {
 139                 WARN_ON_ONCE(1);
 140                 return IRQ_NONE;
 141         }
 142
 143         client = phy->i2c_dev;
 144         dev_dbg(&client->dev, "IRQ\n");
 145
 146         if (phy->hard_fault != 0)
 147                 return IRQ_HANDLED;
 148
 149         r = pn533_i2c_read(phy, &skb);
 150         if (r == -EREMOTEIO) {
 151                 phy->hard_fault = r;
 152
 153                 pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
 154
 155                 return IRQ_HANDLED;
 156         } else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
 157                 return IRQ_HANDLED;
 158         }
 159
 160         if (!phy->aborted)
 161                 pn533_recv_frame(phy->priv, skb, 0);
 162
 163         return IRQ_HANDLED;
 164 }
 165
 166 static struct pn533_phy_ops i2c_phy_ops = {
 167         .send_frame = pn533_i2c_send_frame,
 168         .send_ack = pn533_i2c_send_ack,
 169         .abort_cmd = pn533_i2c_abort_cmd,
 170 };
 171
 172
 173 static int pn533_i2c_probe(struct i2c_client *client,
 174                                const struct i2c_device_id *id)
 175 {
 176         struct pn533_i2c_phy *phy;
 177         struct pn533 *priv;
 178         int r = 0;
 179
 180         dev_dbg(&client->dev, "%s\n", __func__);
 181         dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
 182
 183         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 184                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 185                 return -ENODEV;
 186         }
 187
 188         phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
 189                            GFP_KERNEL);
 190         if (!phy)
 191                 return -ENOMEM;
 192
 193         phy->i2c_dev = client;
 194         i2c_set_clientdata(client, phy);
 195
 196         priv = pn533_register_device(PN533_DEVICE_PN532,
 197                                      PN533_NO_TYPE_B_PROTOCOLS,
 198                                      PN533_PROTO_REQ_ACK_RESP,
 199                                      phy, &i2c_phy_ops, NULL,
 200                                      &phy->i2c_dev->dev,
 201                                      &client->dev);
 202
 203         if (IS_ERR(priv)) {
 204                 r = PTR_ERR(priv);
 205                 return r;
 206         }
 207
 208         phy->priv = priv;
 209
 210         r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
 211                                 IRQF_TRIGGER_FALLING |
 212                                 IRQF_SHARED | IRQF_ONESHOT,
 213                                 PN533_I2C_DRIVER_NAME, phy);
 214         if (r < 0) {
 215                 nfc_err(&client->dev, "Unable to register IRQ handler\n");
 216                 goto irq_rqst_err;
 217         }
 218
 219         r = pn533_finalize_setup(priv);
 220         if (r)
 221                 goto fn_setup_err;
 222
 223         return 0;
 224
 225 fn_setup_err:
 226         free_irq(client->irq, phy);
 227
 228 irq_rqst_err:
 229         pn533_unregister_device(phy->priv);
 230
 231         return r;
 232 }
 233
 234 static int pn533_i2c_remove(struct i2c_client *client)
 235 {
 236         struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
 237
 238         dev_dbg(&client->dev, "%s\n", __func__);
 239
 240         free_irq(client->irq, phy);
 241
 242         pn533_unregister_device(phy->priv);
 243
 244         return 0;
 245 }
 246
 247 static const struct of_device_id of_pn533_i2c_match[] = {
 248         { .compatible = "nxp,pn533-i2c", },
 249         { .compatible = "nxp,pn532-i2c", },
 250         {},
 251 };
 252 MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
 253
 254 static const struct i2c_device_id pn533_i2c_id_table[] = {
 255         { PN533_I2C_DRIVER_NAME, 0 },
 256         {}
 257 };
 258 MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
 259
 260 static struct i2c_driver pn533_i2c_driver = {
 261         .driver = {
 262                    .name = PN533_I2C_DRIVER_NAME,
 263                    .owner = THIS_MODULE,
 264                    .of_match_table = of_match_ptr(of_pn533_i2c_match),
 265                   },
 266         .probe = pn533_i2c_probe,
 267         .id_table = pn533_i2c_id_table,
 268         .remove = pn533_i2c_remove,
 269 };
 270
 271 module_i2c_driver(pn533_i2c_driver);
 272
 273 MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
 274 MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
 275 MODULE_VERSION(VERSION);
 276 MODULE_LICENSE("GPL");