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, 0 }, 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"); 273