1 /* 2 * I2C link layer for the NXP NCI driver 3 * 4 * Copyright (C) 2014 NXP Semiconductors All rights reserved. 5 * Copyright (C) 2012-2015 Intel Corporation. All rights reserved. 6 * 7 * Authors: Clément Perrochaud <clement.perrochaud@nxp.com> 8 * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com> 9 * 10 * Derived from PN544 device driver: 11 * Copyright (C) 2012 Intel Corporation. All rights reserved. 12 * 13 * This program is free software; you can redistribute it and/or modify it 14 * under the terms and conditions of the GNU General Public License, 15 * version 2, as published by the Free Software Foundation. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, see <http://www.gnu.org/licenses/>. 24 */ 25 26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 27 28 #include <linux/acpi.h> 29 #include <linux/delay.h> 30 #include <linux/i2c.h> 31 #include <linux/interrupt.h> 32 #include <linux/module.h> 33 #include <linux/nfc.h> 34 #include <linux/gpio/consumer.h> 35 #include <linux/of_gpio.h> 36 #include <linux/of_irq.h> 37 #include <linux/platform_data/nxp-nci.h> 38 #include <asm/unaligned.h> 39 40 #include <net/nfc/nfc.h> 41 42 #include "nxp-nci.h" 43 44 #define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c" 45 46 #define NXP_NCI_I2C_MAX_PAYLOAD 32 47 48 struct nxp_nci_i2c_phy { 49 struct i2c_client *i2c_dev; 50 struct nci_dev *ndev; 51 52 unsigned int gpio_en; 53 unsigned int gpio_fw; 54 55 int hard_fault; /* 56 * < 0 if hardware error occurred (e.g. i2c err) 57 * and prevents normal operation. 58 */ 59 }; 60 61 static int nxp_nci_i2c_set_mode(void *phy_id, 62 enum nxp_nci_mode mode) 63 { 64 struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id; 65 66 gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0); 67 gpio_set_value(phy->gpio_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0); 68 usleep_range(10000, 15000); 69 70 if (mode == NXP_NCI_MODE_COLD) 71 phy->hard_fault = 0; 72 73 return 0; 74 } 75 76 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb) 77 { 78 int r; 79 struct nxp_nci_i2c_phy *phy = phy_id; 80 struct i2c_client *client = phy->i2c_dev; 81 82 if (phy->hard_fault != 0) 83 return phy->hard_fault; 84 85 r = i2c_master_send(client, skb->data, skb->len); 86 if (r < 0) { 87 /* Retry, chip was in standby */ 88 msleep(110); 89 r = i2c_master_send(client, skb->data, skb->len); 90 } 91 92 if (r < 0) { 93 nfc_err(&client->dev, "Error %d on I2C send\n", r); 94 } else if (r != skb->len) { 95 nfc_err(&client->dev, 96 "Invalid length sent: %u (expected %u)\n", 97 r, skb->len); 98 r = -EREMOTEIO; 99 } else { 100 /* Success but return 0 and not number of bytes */ 101 r = 0; 102 } 103 104 return r; 105 } 106 107 static const struct nxp_nci_phy_ops i2c_phy_ops = { 108 .set_mode = nxp_nci_i2c_set_mode, 109 .write = nxp_nci_i2c_write, 110 }; 111 112 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy, 113 struct sk_buff **skb) 114 { 115 struct i2c_client *client = phy->i2c_dev; 116 u16 header; 117 size_t frame_len; 118 int r; 119 120 r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN); 121 if (r < 0) { 122 goto fw_read_exit; 123 } else if (r != NXP_NCI_FW_HDR_LEN) { 124 nfc_err(&client->dev, "Incorrect header length: %u\n", r); 125 r = -EBADMSG; 126 goto fw_read_exit; 127 } 128 129 frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) + 130 NXP_NCI_FW_CRC_LEN; 131 132 *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL); 133 if (*skb == NULL) { 134 r = -ENOMEM; 135 goto fw_read_exit; 136 } 137 138 memcpy(skb_put(*skb, NXP_NCI_FW_HDR_LEN), &header, NXP_NCI_FW_HDR_LEN); 139 140 r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len); 141 if (r != frame_len) { 142 nfc_err(&client->dev, 143 "Invalid frame length: %u (expected %zu)\n", 144 r, frame_len); 145 r = -EBADMSG; 146 goto fw_read_exit_free_skb; 147 } 148 149 return 0; 150 151 fw_read_exit_free_skb: 152 kfree_skb(*skb); 153 fw_read_exit: 154 return r; 155 } 156 157 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy, 158 struct sk_buff **skb) 159 { 160 struct nci_ctrl_hdr header; /* May actually be a data header */ 161 struct i2c_client *client = phy->i2c_dev; 162 int r; 163 164 r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE); 165 if (r < 0) { 166 goto nci_read_exit; 167 } else if (r != NCI_CTRL_HDR_SIZE) { 168 nfc_err(&client->dev, "Incorrect header length: %u\n", r); 169 r = -EBADMSG; 170 goto nci_read_exit; 171 } 172 173 *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL); 174 if (*skb == NULL) { 175 r = -ENOMEM; 176 goto nci_read_exit; 177 } 178 179 memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), (void *) &header, 180 NCI_CTRL_HDR_SIZE); 181 182 r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen); 183 if (r != header.plen) { 184 nfc_err(&client->dev, 185 "Invalid frame payload length: %u (expected %u)\n", 186 r, header.plen); 187 r = -EBADMSG; 188 goto nci_read_exit_free_skb; 189 } 190 191 return 0; 192 193 nci_read_exit_free_skb: 194 kfree_skb(*skb); 195 nci_read_exit: 196 return r; 197 } 198 199 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id) 200 { 201 struct nxp_nci_i2c_phy *phy = phy_id; 202 struct i2c_client *client; 203 struct nxp_nci_info *info; 204 205 struct sk_buff *skb = NULL; 206 int r = 0; 207 208 if (!phy || !phy->ndev) 209 goto exit_irq_none; 210 211 client = phy->i2c_dev; 212 213 if (!client || irq != client->irq) 214 goto exit_irq_none; 215 216 info = nci_get_drvdata(phy->ndev); 217 218 if (!info) 219 goto exit_irq_none; 220 221 mutex_lock(&info->info_lock); 222 223 if (phy->hard_fault != 0) 224 goto exit_irq_handled; 225 226 switch (info->mode) { 227 case NXP_NCI_MODE_NCI: 228 r = nxp_nci_i2c_nci_read(phy, &skb); 229 break; 230 case NXP_NCI_MODE_FW: 231 r = nxp_nci_i2c_fw_read(phy, &skb); 232 break; 233 case NXP_NCI_MODE_COLD: 234 r = -EREMOTEIO; 235 break; 236 } 237 238 if (r == -EREMOTEIO) { 239 phy->hard_fault = r; 240 skb = NULL; 241 } else if (r < 0) { 242 nfc_err(&client->dev, "Read failed with error %d\n", r); 243 goto exit_irq_handled; 244 } 245 246 switch (info->mode) { 247 case NXP_NCI_MODE_NCI: 248 nci_recv_frame(phy->ndev, skb); 249 break; 250 case NXP_NCI_MODE_FW: 251 nxp_nci_fw_recv_frame(phy->ndev, skb); 252 break; 253 case NXP_NCI_MODE_COLD: 254 break; 255 } 256 257 exit_irq_handled: 258 mutex_unlock(&info->info_lock); 259 return IRQ_HANDLED; 260 exit_irq_none: 261 WARN_ON_ONCE(1); 262 return IRQ_NONE; 263 } 264 265 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client) 266 { 267 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client); 268 struct device_node *pp; 269 int r; 270 271 pp = client->dev.of_node; 272 if (!pp) 273 return -ENODEV; 274 275 r = of_get_named_gpio(pp, "enable-gpios", 0); 276 if (r == -EPROBE_DEFER) 277 r = of_get_named_gpio(pp, "enable-gpios", 0); 278 if (r < 0) { 279 nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r); 280 return r; 281 } 282 phy->gpio_en = r; 283 284 r = of_get_named_gpio(pp, "firmware-gpios", 0); 285 if (r == -EPROBE_DEFER) 286 r = of_get_named_gpio(pp, "firmware-gpios", 0); 287 if (r < 0) { 288 nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r); 289 return r; 290 } 291 phy->gpio_fw = r; 292 293 return 0; 294 } 295 296 static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy) 297 { 298 struct i2c_client *client = phy->i2c_dev; 299 struct gpio_desc *gpiod_en, *gpiod_fw; 300 301 gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW); 302 gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW); 303 304 if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw)) { 305 nfc_err(&client->dev, "No GPIOs\n"); 306 return -EINVAL; 307 } 308 309 phy->gpio_en = desc_to_gpio(gpiod_en); 310 phy->gpio_fw = desc_to_gpio(gpiod_fw); 311 312 return 0; 313 } 314 315 static int nxp_nci_i2c_probe(struct i2c_client *client, 316 const struct i2c_device_id *id) 317 { 318 struct nxp_nci_i2c_phy *phy; 319 struct nxp_nci_nfc_platform_data *pdata; 320 int r; 321 322 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 323 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 324 r = -ENODEV; 325 goto probe_exit; 326 } 327 328 phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy), 329 GFP_KERNEL); 330 if (!phy) { 331 r = -ENOMEM; 332 goto probe_exit; 333 } 334 335 phy->i2c_dev = client; 336 i2c_set_clientdata(client, phy); 337 338 pdata = client->dev.platform_data; 339 340 if (!pdata && client->dev.of_node) { 341 r = nxp_nci_i2c_parse_devtree(client); 342 if (r < 0) { 343 nfc_err(&client->dev, "Failed to get DT data\n"); 344 goto probe_exit; 345 } 346 } else if (pdata) { 347 phy->gpio_en = pdata->gpio_en; 348 phy->gpio_fw = pdata->gpio_fw; 349 } else if (ACPI_HANDLE(&client->dev)) { 350 r = nxp_nci_i2c_acpi_config(phy); 351 if (r < 0) 352 goto probe_exit; 353 goto nci_probe; 354 } else { 355 nfc_err(&client->dev, "No platform data\n"); 356 r = -EINVAL; 357 goto probe_exit; 358 } 359 360 r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en, 361 GPIOF_OUT_INIT_LOW, "nxp_nci_en"); 362 if (r < 0) 363 goto probe_exit; 364 365 r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw, 366 GPIOF_OUT_INIT_LOW, "nxp_nci_fw"); 367 if (r < 0) 368 goto probe_exit; 369 370 nci_probe: 371 r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops, 372 NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev); 373 if (r < 0) 374 goto probe_exit; 375 376 r = request_threaded_irq(client->irq, NULL, 377 nxp_nci_i2c_irq_thread_fn, 378 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 379 NXP_NCI_I2C_DRIVER_NAME, phy); 380 if (r < 0) 381 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 382 383 probe_exit: 384 return r; 385 } 386 387 static int nxp_nci_i2c_remove(struct i2c_client *client) 388 { 389 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client); 390 391 nxp_nci_remove(phy->ndev); 392 free_irq(client->irq, phy); 393 394 return 0; 395 } 396 397 static struct i2c_device_id nxp_nci_i2c_id_table[] = { 398 {"nxp-nci_i2c", 0}, 399 {} 400 }; 401 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table); 402 403 static const struct of_device_id of_nxp_nci_i2c_match[] = { 404 { .compatible = "nxp,nxp-nci-i2c", }, 405 {}, 406 }; 407 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match); 408 409 #ifdef CONFIG_ACPI 410 static struct acpi_device_id acpi_id[] = { 411 { "NXP7471" }, 412 { }, 413 }; 414 MODULE_DEVICE_TABLE(acpi, acpi_id); 415 #endif 416 417 static struct i2c_driver nxp_nci_i2c_driver = { 418 .driver = { 419 .name = NXP_NCI_I2C_DRIVER_NAME, 420 .acpi_match_table = ACPI_PTR(acpi_id), 421 .of_match_table = of_match_ptr(of_nxp_nci_i2c_match), 422 }, 423 .probe = nxp_nci_i2c_probe, 424 .id_table = nxp_nci_i2c_id_table, 425 .remove = nxp_nci_i2c_remove, 426 }; 427 428 module_i2c_driver(nxp_nci_i2c_driver); 429 430 MODULE_LICENSE("GPL"); 431 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers"); 432 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>"); 433 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>"); 434