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"); 277