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 = pn53x_common_init(PN533_DEVICE_PN532, 197 PN533_PROTO_REQ_ACK_RESP, 198 phy, &i2c_phy_ops, NULL, 199 &phy->i2c_dev->dev); 200 201 if (IS_ERR(priv)) { 202 r = PTR_ERR(priv); 203 return r; 204 } 205 206 phy->priv = priv; 207 r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev); 208 if (r) 209 goto nfc_alloc_err; 210 211 r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn, 212 IRQF_TRIGGER_FALLING | 213 IRQF_SHARED | IRQF_ONESHOT, 214 PN533_I2C_DRIVER_NAME, phy); 215 if (r < 0) { 216 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 217 goto irq_rqst_err; 218 } 219 220 r = pn533_finalize_setup(priv); 221 if (r) 222 goto fn_setup_err; 223 224 r = nfc_register_device(priv->nfc_dev); 225 if (r) 226 goto fn_setup_err; 227 228 return r; 229 230 fn_setup_err: 231 free_irq(client->irq, phy); 232 233 irq_rqst_err: 234 nfc_free_device(priv->nfc_dev); 235 236 nfc_alloc_err: 237 pn53x_common_clean(phy->priv); 238 239 return r; 240 } 241 242 static int pn533_i2c_remove(struct i2c_client *client) 243 { 244 struct pn533_i2c_phy *phy = i2c_get_clientdata(client); 245 246 dev_dbg(&client->dev, "%s\n", __func__); 247 248 free_irq(client->irq, phy); 249 250 pn53x_unregister_nfc(phy->priv); 251 pn53x_common_clean(phy->priv); 252 253 return 0; 254 } 255 256 static const struct of_device_id of_pn533_i2c_match[] = { 257 { .compatible = "nxp,pn532", }, 258 /* 259 * NOTE: The use of the compatibles with the trailing "...-i2c" is 260 * deprecated and will be removed. 261 */ 262 { .compatible = "nxp,pn533-i2c", }, 263 { .compatible = "nxp,pn532-i2c", }, 264 {}, 265 }; 266 MODULE_DEVICE_TABLE(of, of_pn533_i2c_match); 267 268 static const struct i2c_device_id pn533_i2c_id_table[] = { 269 { PN533_I2C_DRIVER_NAME, 0 }, 270 {} 271 }; 272 MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table); 273 274 static struct i2c_driver pn533_i2c_driver = { 275 .driver = { 276 .name = PN533_I2C_DRIVER_NAME, 277 .of_match_table = of_match_ptr(of_pn533_i2c_match), 278 }, 279 .probe = pn533_i2c_probe, 280 .id_table = pn533_i2c_id_table, 281 .remove = pn533_i2c_remove, 282 }; 283 284 module_i2c_driver(pn533_i2c_driver); 285 286 MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>"); 287 MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION); 288 MODULE_VERSION(VERSION); 289 MODULE_LICENSE("GPL"); 290