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/irq.h> 20 #include <linux/module.h> 21 #include <linux/nfc.h> 22 #include <linux/gpio/consumer.h> 23 #include <linux/unaligned.h> 24 25 #include <net/nfc/nfc.h> 26 27 #include "nxp-nci.h" 28 29 #define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c" 30 31 #define NXP_NCI_I2C_MAX_PAYLOAD 32 32 33 struct nxp_nci_i2c_phy { 34 struct i2c_client *i2c_dev; 35 struct nci_dev *ndev; 36 37 struct gpio_desc *gpiod_en; 38 struct gpio_desc *gpiod_fw; 39 40 int hard_fault; /* 41 * < 0 if hardware error occurred (e.g. i2c err) 42 * and prevents normal operation. 43 */ 44 }; 45 46 static int nxp_nci_i2c_set_mode(void *phy_id, 47 enum nxp_nci_mode mode) 48 { 49 struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id; 50 51 gpiod_set_value_cansleep(phy->gpiod_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0); 52 gpiod_set_value_cansleep(phy->gpiod_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0); 53 usleep_range(10000, 15000); 54 55 if (mode == NXP_NCI_MODE_COLD) 56 phy->hard_fault = 0; 57 58 return 0; 59 } 60 61 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb) 62 { 63 int r; 64 struct nxp_nci_i2c_phy *phy = phy_id; 65 struct i2c_client *client = phy->i2c_dev; 66 67 if (phy->hard_fault != 0) 68 return phy->hard_fault; 69 70 r = i2c_master_send(client, skb->data, skb->len); 71 if (r < 0) { 72 /* Retry, chip was in standby */ 73 msleep(110); 74 r = i2c_master_send(client, skb->data, skb->len); 75 } 76 77 if (r < 0) { 78 nfc_err(&client->dev, "Error %d on I2C send\n", r); 79 } else if (r != skb->len) { 80 nfc_err(&client->dev, 81 "Invalid length sent: %u (expected %u)\n", 82 r, skb->len); 83 r = -EREMOTEIO; 84 } else { 85 /* Success but return 0 and not number of bytes */ 86 r = 0; 87 } 88 89 return r; 90 } 91 92 static const struct nxp_nci_phy_ops i2c_phy_ops = { 93 .set_mode = nxp_nci_i2c_set_mode, 94 .write = nxp_nci_i2c_write, 95 }; 96 97 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy, 98 struct sk_buff **skb) 99 { 100 struct i2c_client *client = phy->i2c_dev; 101 size_t frame_len; 102 __be16 header; 103 int r; 104 105 r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN); 106 if (r < 0) { 107 goto fw_read_exit; 108 } else if (r != NXP_NCI_FW_HDR_LEN) { 109 nfc_err(&client->dev, "Incorrect header length: %u\n", r); 110 r = -EBADMSG; 111 goto fw_read_exit; 112 } 113 114 frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) + 115 NXP_NCI_FW_CRC_LEN; 116 117 *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL); 118 if (*skb == NULL) { 119 r = -ENOMEM; 120 goto fw_read_exit; 121 } 122 123 skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN); 124 125 r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len); 126 if (r < 0) { 127 goto fw_read_exit_free_skb; 128 } else if (r != frame_len) { 129 nfc_err(&client->dev, 130 "Invalid frame length: %u (expected %zu)\n", 131 r, frame_len); 132 r = -EBADMSG; 133 goto fw_read_exit_free_skb; 134 } 135 136 return 0; 137 138 fw_read_exit_free_skb: 139 kfree_skb(*skb); 140 fw_read_exit: 141 return r; 142 } 143 144 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy, 145 struct sk_buff **skb) 146 { 147 struct nci_ctrl_hdr header; /* May actually be a data header */ 148 struct i2c_client *client = phy->i2c_dev; 149 int r; 150 151 r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE); 152 if (r < 0) { 153 goto nci_read_exit; 154 } else if (r != NCI_CTRL_HDR_SIZE) { 155 nfc_err(&client->dev, "Incorrect header length: %u\n", r); 156 r = -EBADMSG; 157 goto nci_read_exit; 158 } 159 160 *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL); 161 if (*skb == NULL) { 162 r = -ENOMEM; 163 goto nci_read_exit; 164 } 165 166 skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE); 167 168 if (!header.plen) 169 return 0; 170 171 r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen); 172 if (r < 0) { 173 goto nci_read_exit_free_skb; 174 } else if (r != header.plen) { 175 nfc_err(&client->dev, 176 "Invalid frame payload length: %u (expected %u)\n", 177 r, header.plen); 178 r = -EBADMSG; 179 goto nci_read_exit_free_skb; 180 } 181 182 return 0; 183 184 nci_read_exit_free_skb: 185 kfree_skb(*skb); 186 nci_read_exit: 187 return r; 188 } 189 190 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id) 191 { 192 struct nxp_nci_i2c_phy *phy = phy_id; 193 struct i2c_client *client; 194 struct nxp_nci_info *info; 195 196 struct sk_buff *skb = NULL; 197 int r = 0; 198 199 if (!phy || !phy->ndev) 200 goto exit_irq_none; 201 202 client = phy->i2c_dev; 203 204 if (!client || irq != client->irq) 205 goto exit_irq_none; 206 207 info = nci_get_drvdata(phy->ndev); 208 209 if (!info) 210 goto exit_irq_none; 211 212 mutex_lock(&info->info_lock); 213 214 if (phy->hard_fault != 0) 215 goto exit_irq_handled; 216 217 switch (info->mode) { 218 case NXP_NCI_MODE_NCI: 219 r = nxp_nci_i2c_nci_read(phy, &skb); 220 break; 221 case NXP_NCI_MODE_FW: 222 r = nxp_nci_i2c_fw_read(phy, &skb); 223 break; 224 case NXP_NCI_MODE_COLD: 225 r = -EREMOTEIO; 226 break; 227 } 228 229 if (r == -EREMOTEIO) { 230 phy->hard_fault = r; 231 if (info->mode == NXP_NCI_MODE_FW) 232 nxp_nci_fw_recv_frame(phy->ndev, NULL); 233 } 234 if (r == -ENXIO) { 235 /* 236 * -ENXIO may occur if the controller has not yet 237 * provided data after asserting IRQ. 238 */ 239 dev_dbg(&client->dev, "No data available yet\n"); 240 goto exit_irq_handled; 241 } 242 if (r < 0) { 243 nfc_err(&client->dev, "Read failed with error %d\n", r); 244 goto exit_irq_handled; 245 } 246 247 switch (info->mode) { 248 case NXP_NCI_MODE_NCI: 249 nci_recv_frame(phy->ndev, skb); 250 break; 251 case NXP_NCI_MODE_FW: 252 nxp_nci_fw_recv_frame(phy->ndev, skb); 253 break; 254 case NXP_NCI_MODE_COLD: 255 break; 256 } 257 258 exit_irq_handled: 259 mutex_unlock(&info->info_lock); 260 return IRQ_HANDLED; 261 exit_irq_none: 262 WARN_ON_ONCE(1); 263 return IRQ_NONE; 264 } 265 266 static const struct acpi_gpio_params firmware_gpios = { 1, 0, false }; 267 static const struct acpi_gpio_params enable_gpios = { 2, 0, false }; 268 269 static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = { 270 { "enable-gpios", &enable_gpios, 1 }, 271 { "firmware-gpios", &firmware_gpios, 1 }, 272 { } 273 }; 274 275 static int nxp_nci_i2c_probe(struct i2c_client *client) 276 { 277 struct device *dev = &client->dev; 278 struct nxp_nci_i2c_phy *phy; 279 unsigned long irqflags; 280 int r; 281 282 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 283 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 284 return -ENODEV; 285 } 286 287 phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy), 288 GFP_KERNEL); 289 if (!phy) 290 return -ENOMEM; 291 292 phy->i2c_dev = client; 293 i2c_set_clientdata(client, phy); 294 295 r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios); 296 if (r) 297 dev_dbg(dev, "Unable to add GPIO mapping table\n"); 298 299 phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW); 300 if (IS_ERR(phy->gpiod_en)) { 301 nfc_err(dev, "Failed to get EN gpio\n"); 302 return PTR_ERR(phy->gpiod_en); 303 } 304 305 phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW); 306 if (IS_ERR(phy->gpiod_fw)) { 307 nfc_err(dev, "Failed to get FW gpio\n"); 308 return PTR_ERR(phy->gpiod_fw); 309 } 310 311 r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops, 312 NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev); 313 if (r < 0) 314 return r; 315 316 /* 317 * ACPI platforms may report incorrect IRQ trigger types 318 * (e.g. level-high), which can lead to interrupt storms. 319 * 320 * Use the historically stable rising-edge trigger for ACPI devices. 321 * 322 * On non-ACPI systems (e.g. Device Tree), prefer the firmware- 323 * provided trigger type, falling back to rising-edge if not set. 324 */ 325 if (ACPI_COMPANION(dev)) { 326 irqflags = IRQF_TRIGGER_RISING; 327 } else { 328 irqflags = irq_get_trigger_type(client->irq); 329 if (!irqflags) 330 irqflags = IRQF_TRIGGER_RISING; 331 } 332 333 r = request_threaded_irq(client->irq, NULL, 334 nxp_nci_i2c_irq_thread_fn, 335 irqflags | IRQF_ONESHOT, 336 NXP_NCI_I2C_DRIVER_NAME, phy); 337 if (r < 0) { 338 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 339 nxp_nci_remove(phy->ndev); 340 } 341 342 return r; 343 } 344 345 static void nxp_nci_i2c_remove(struct i2c_client *client) 346 { 347 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client); 348 349 nxp_nci_remove(phy->ndev); 350 free_irq(client->irq, phy); 351 } 352 353 static const struct i2c_device_id nxp_nci_i2c_id_table[] = { 354 { .name = "nxp-nci_i2c" }, 355 { } 356 }; 357 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table); 358 359 static const struct of_device_id of_nxp_nci_i2c_match[] = { 360 { .compatible = "nxp,nxp-nci-i2c" }, 361 { } 362 }; 363 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match); 364 365 #ifdef CONFIG_ACPI 366 static const struct acpi_device_id acpi_id[] = { 367 { .id = "NXP1001" }, 368 { .id = "NXP1002" }, 369 { .id = "NXP7471" }, 370 { } 371 }; 372 MODULE_DEVICE_TABLE(acpi, acpi_id); 373 #endif 374 375 static struct i2c_driver nxp_nci_i2c_driver = { 376 .driver = { 377 .name = NXP_NCI_I2C_DRIVER_NAME, 378 .acpi_match_table = ACPI_PTR(acpi_id), 379 .of_match_table = of_nxp_nci_i2c_match, 380 }, 381 .probe = nxp_nci_i2c_probe, 382 .id_table = nxp_nci_i2c_id_table, 383 .remove = nxp_nci_i2c_remove, 384 }; 385 386 module_i2c_driver(nxp_nci_i2c_driver); 387 388 MODULE_LICENSE("GPL"); 389 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers"); 390 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>"); 391 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>"); 392