1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * I2C link layer for the NXP NCI driver 4 * 5 * Copyright (C) 2014 NXP Semiconductors All rights reserved. 6 * Copyright (C) 2012-2015 Intel Corporation. All rights reserved. 7 * 8 * Authors: Clément Perrochaud <clement.perrochaud@nxp.com> 9 * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com> 10 * 11 * Derived from PN544 device driver: 12 * Copyright (C) 2012 Intel Corporation. All rights reserved. 13 */ 14 15 #include <linux/acpi.h> 16 #include <linux/delay.h> 17 #include <linux/i2c.h> 18 #include <linux/interrupt.h> 19 #include <linux/module.h> 20 #include <linux/nfc.h> 21 #include <linux/gpio/consumer.h> 22 #include <asm/unaligned.h> 23 24 #include <net/nfc/nfc.h> 25 26 #include "nxp-nci.h" 27 28 #define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c" 29 30 #define NXP_NCI_I2C_MAX_PAYLOAD 32 31 32 struct nxp_nci_i2c_phy { 33 struct i2c_client *i2c_dev; 34 struct nci_dev *ndev; 35 36 struct gpio_desc *gpiod_en; 37 struct gpio_desc *gpiod_fw; 38 39 int hard_fault; /* 40 * < 0 if hardware error occurred (e.g. i2c err) 41 * and prevents normal operation. 42 */ 43 }; 44 45 static int nxp_nci_i2c_set_mode(void *phy_id, 46 enum nxp_nci_mode mode) 47 { 48 struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id; 49 50 gpiod_set_value(phy->gpiod_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0); 51 gpiod_set_value(phy->gpiod_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0); 52 usleep_range(10000, 15000); 53 54 if (mode == NXP_NCI_MODE_COLD) 55 phy->hard_fault = 0; 56 57 return 0; 58 } 59 60 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb) 61 { 62 int r; 63 struct nxp_nci_i2c_phy *phy = phy_id; 64 struct i2c_client *client = phy->i2c_dev; 65 66 if (phy->hard_fault != 0) 67 return phy->hard_fault; 68 69 r = i2c_master_send(client, skb->data, skb->len); 70 if (r < 0) { 71 /* Retry, chip was in standby */ 72 msleep(110); 73 r = i2c_master_send(client, skb->data, skb->len); 74 } 75 76 if (r < 0) { 77 nfc_err(&client->dev, "Error %d on I2C send\n", r); 78 } else if (r != skb->len) { 79 nfc_err(&client->dev, 80 "Invalid length sent: %u (expected %u)\n", 81 r, skb->len); 82 r = -EREMOTEIO; 83 } else { 84 /* Success but return 0 and not number of bytes */ 85 r = 0; 86 } 87 88 return r; 89 } 90 91 static const struct nxp_nci_phy_ops i2c_phy_ops = { 92 .set_mode = nxp_nci_i2c_set_mode, 93 .write = nxp_nci_i2c_write, 94 }; 95 96 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy, 97 struct sk_buff **skb) 98 { 99 struct i2c_client *client = phy->i2c_dev; 100 u16 header; 101 size_t frame_len; 102 int r; 103 104 r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN); 105 if (r < 0) { 106 goto fw_read_exit; 107 } else if (r != NXP_NCI_FW_HDR_LEN) { 108 nfc_err(&client->dev, "Incorrect header length: %u\n", r); 109 r = -EBADMSG; 110 goto fw_read_exit; 111 } 112 113 frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) + 114 NXP_NCI_FW_CRC_LEN; 115 116 *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL); 117 if (*skb == NULL) { 118 r = -ENOMEM; 119 goto fw_read_exit; 120 } 121 122 skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN); 123 124 r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len); 125 if (r < 0) { 126 goto fw_read_exit_free_skb; 127 } else if (r != frame_len) { 128 nfc_err(&client->dev, 129 "Invalid frame length: %u (expected %zu)\n", 130 r, frame_len); 131 r = -EBADMSG; 132 goto fw_read_exit_free_skb; 133 } 134 135 return 0; 136 137 fw_read_exit_free_skb: 138 kfree_skb(*skb); 139 fw_read_exit: 140 return r; 141 } 142 143 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy, 144 struct sk_buff **skb) 145 { 146 struct nci_ctrl_hdr header; /* May actually be a data header */ 147 struct i2c_client *client = phy->i2c_dev; 148 int r; 149 150 r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE); 151 if (r < 0) { 152 goto nci_read_exit; 153 } else if (r != NCI_CTRL_HDR_SIZE) { 154 nfc_err(&client->dev, "Incorrect header length: %u\n", r); 155 r = -EBADMSG; 156 goto nci_read_exit; 157 } 158 159 *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL); 160 if (*skb == NULL) { 161 r = -ENOMEM; 162 goto nci_read_exit; 163 } 164 165 skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE); 166 167 if (!header.plen) 168 return 0; 169 170 r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen); 171 if (r < 0) { 172 goto nci_read_exit_free_skb; 173 } else if (r != header.plen) { 174 nfc_err(&client->dev, 175 "Invalid frame payload length: %u (expected %u)\n", 176 r, header.plen); 177 r = -EBADMSG; 178 goto nci_read_exit_free_skb; 179 } 180 181 return 0; 182 183 nci_read_exit_free_skb: 184 kfree_skb(*skb); 185 nci_read_exit: 186 return r; 187 } 188 189 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id) 190 { 191 struct nxp_nci_i2c_phy *phy = phy_id; 192 struct i2c_client *client; 193 struct nxp_nci_info *info; 194 195 struct sk_buff *skb = NULL; 196 int r = 0; 197 198 if (!phy || !phy->ndev) 199 goto exit_irq_none; 200 201 client = phy->i2c_dev; 202 203 if (!client || irq != client->irq) 204 goto exit_irq_none; 205 206 info = nci_get_drvdata(phy->ndev); 207 208 if (!info) 209 goto exit_irq_none; 210 211 mutex_lock(&info->info_lock); 212 213 if (phy->hard_fault != 0) 214 goto exit_irq_handled; 215 216 switch (info->mode) { 217 case NXP_NCI_MODE_NCI: 218 r = nxp_nci_i2c_nci_read(phy, &skb); 219 break; 220 case NXP_NCI_MODE_FW: 221 r = nxp_nci_i2c_fw_read(phy, &skb); 222 break; 223 case NXP_NCI_MODE_COLD: 224 r = -EREMOTEIO; 225 break; 226 } 227 228 if (r == -EREMOTEIO) { 229 phy->hard_fault = r; 230 if (info->mode == NXP_NCI_MODE_FW) 231 nxp_nci_fw_recv_frame(phy->ndev, NULL); 232 } 233 if (r < 0) { 234 nfc_err(&client->dev, "Read failed with error %d\n", r); 235 goto exit_irq_handled; 236 } 237 238 switch (info->mode) { 239 case NXP_NCI_MODE_NCI: 240 nci_recv_frame(phy->ndev, skb); 241 break; 242 case NXP_NCI_MODE_FW: 243 nxp_nci_fw_recv_frame(phy->ndev, skb); 244 break; 245 case NXP_NCI_MODE_COLD: 246 break; 247 } 248 249 exit_irq_handled: 250 mutex_unlock(&info->info_lock); 251 return IRQ_HANDLED; 252 exit_irq_none: 253 WARN_ON_ONCE(1); 254 return IRQ_NONE; 255 } 256 257 static const struct acpi_gpio_params firmware_gpios = { 1, 0, false }; 258 static const struct acpi_gpio_params enable_gpios = { 2, 0, false }; 259 260 static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = { 261 { "enable-gpios", &enable_gpios, 1 }, 262 { "firmware-gpios", &firmware_gpios, 1 }, 263 { } 264 }; 265 266 static int nxp_nci_i2c_probe(struct i2c_client *client, 267 const struct i2c_device_id *id) 268 { 269 struct device *dev = &client->dev; 270 struct nxp_nci_i2c_phy *phy; 271 int r; 272 273 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 274 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 275 return -ENODEV; 276 } 277 278 phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy), 279 GFP_KERNEL); 280 if (!phy) 281 return -ENOMEM; 282 283 phy->i2c_dev = client; 284 i2c_set_clientdata(client, phy); 285 286 r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios); 287 if (r) 288 dev_dbg(dev, "Unable to add GPIO mapping table\n"); 289 290 phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW); 291 if (IS_ERR(phy->gpiod_en)) { 292 nfc_err(dev, "Failed to get EN gpio\n"); 293 return PTR_ERR(phy->gpiod_en); 294 } 295 296 phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW); 297 if (IS_ERR(phy->gpiod_fw)) { 298 nfc_err(dev, "Failed to get FW gpio\n"); 299 return PTR_ERR(phy->gpiod_fw); 300 } 301 302 r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops, 303 NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev); 304 if (r < 0) 305 return r; 306 307 r = request_threaded_irq(client->irq, NULL, 308 nxp_nci_i2c_irq_thread_fn, 309 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 310 NXP_NCI_I2C_DRIVER_NAME, phy); 311 if (r < 0) 312 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 313 314 return r; 315 } 316 317 static int nxp_nci_i2c_remove(struct i2c_client *client) 318 { 319 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client); 320 321 nxp_nci_remove(phy->ndev); 322 free_irq(client->irq, phy); 323 324 return 0; 325 } 326 327 static const struct i2c_device_id nxp_nci_i2c_id_table[] = { 328 {"nxp-nci_i2c", 0}, 329 {} 330 }; 331 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table); 332 333 static const struct of_device_id of_nxp_nci_i2c_match[] = { 334 { .compatible = "nxp,nxp-nci-i2c", }, 335 {} 336 }; 337 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match); 338 339 #ifdef CONFIG_ACPI 340 static const struct acpi_device_id acpi_id[] = { 341 { "NXP1001" }, 342 { "NXP7471" }, 343 { } 344 }; 345 MODULE_DEVICE_TABLE(acpi, acpi_id); 346 #endif 347 348 static struct i2c_driver nxp_nci_i2c_driver = { 349 .driver = { 350 .name = NXP_NCI_I2C_DRIVER_NAME, 351 .acpi_match_table = ACPI_PTR(acpi_id), 352 .of_match_table = of_nxp_nci_i2c_match, 353 }, 354 .probe = nxp_nci_i2c_probe, 355 .id_table = nxp_nci_i2c_id_table, 356 .remove = nxp_nci_i2c_remove, 357 }; 358 359 module_i2c_driver(nxp_nci_i2c_driver); 360 361 MODULE_LICENSE("GPL"); 362 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers"); 363 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>"); 364 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>"); 365