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 skb_put_data(*skb, &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 skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE); 180 181 r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen); 182 if (r != header.plen) { 183 nfc_err(&client->dev, 184 "Invalid frame payload length: %u (expected %u)\n", 185 r, header.plen); 186 r = -EBADMSG; 187 goto nci_read_exit_free_skb; 188 } 189 190 return 0; 191 192 nci_read_exit_free_skb: 193 kfree_skb(*skb); 194 nci_read_exit: 195 return r; 196 } 197 198 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id) 199 { 200 struct nxp_nci_i2c_phy *phy = phy_id; 201 struct i2c_client *client; 202 struct nxp_nci_info *info; 203 204 struct sk_buff *skb = NULL; 205 int r = 0; 206 207 if (!phy || !phy->ndev) 208 goto exit_irq_none; 209 210 client = phy->i2c_dev; 211 212 if (!client || irq != client->irq) 213 goto exit_irq_none; 214 215 info = nci_get_drvdata(phy->ndev); 216 217 if (!info) 218 goto exit_irq_none; 219 220 mutex_lock(&info->info_lock); 221 222 if (phy->hard_fault != 0) 223 goto exit_irq_handled; 224 225 switch (info->mode) { 226 case NXP_NCI_MODE_NCI: 227 r = nxp_nci_i2c_nci_read(phy, &skb); 228 break; 229 case NXP_NCI_MODE_FW: 230 r = nxp_nci_i2c_fw_read(phy, &skb); 231 break; 232 case NXP_NCI_MODE_COLD: 233 r = -EREMOTEIO; 234 break; 235 } 236 237 if (r == -EREMOTEIO) { 238 phy->hard_fault = r; 239 skb = NULL; 240 } else if (r < 0) { 241 nfc_err(&client->dev, "Read failed with error %d\n", r); 242 goto exit_irq_handled; 243 } 244 245 switch (info->mode) { 246 case NXP_NCI_MODE_NCI: 247 nci_recv_frame(phy->ndev, skb); 248 break; 249 case NXP_NCI_MODE_FW: 250 nxp_nci_fw_recv_frame(phy->ndev, skb); 251 break; 252 case NXP_NCI_MODE_COLD: 253 break; 254 } 255 256 exit_irq_handled: 257 mutex_unlock(&info->info_lock); 258 return IRQ_HANDLED; 259 exit_irq_none: 260 WARN_ON_ONCE(1); 261 return IRQ_NONE; 262 } 263 264 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client) 265 { 266 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client); 267 struct device_node *pp; 268 int r; 269 270 pp = client->dev.of_node; 271 if (!pp) 272 return -ENODEV; 273 274 r = of_get_named_gpio(pp, "enable-gpios", 0); 275 if (r == -EPROBE_DEFER) 276 r = of_get_named_gpio(pp, "enable-gpios", 0); 277 if (r < 0) { 278 nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r); 279 return r; 280 } 281 phy->gpio_en = r; 282 283 r = of_get_named_gpio(pp, "firmware-gpios", 0); 284 if (r == -EPROBE_DEFER) 285 r = of_get_named_gpio(pp, "firmware-gpios", 0); 286 if (r < 0) { 287 nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r); 288 return r; 289 } 290 phy->gpio_fw = r; 291 292 return 0; 293 } 294 295 static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy) 296 { 297 struct i2c_client *client = phy->i2c_dev; 298 struct gpio_desc *gpiod_en, *gpiod_fw; 299 300 gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW); 301 gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW); 302 303 if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw)) { 304 nfc_err(&client->dev, "No GPIOs\n"); 305 return -EINVAL; 306 } 307 308 phy->gpio_en = desc_to_gpio(gpiod_en); 309 phy->gpio_fw = desc_to_gpio(gpiod_fw); 310 311 return 0; 312 } 313 314 static int nxp_nci_i2c_probe(struct i2c_client *client, 315 const struct i2c_device_id *id) 316 { 317 struct nxp_nci_i2c_phy *phy; 318 struct nxp_nci_nfc_platform_data *pdata; 319 int r; 320 321 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 322 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 323 r = -ENODEV; 324 goto probe_exit; 325 } 326 327 phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy), 328 GFP_KERNEL); 329 if (!phy) { 330 r = -ENOMEM; 331 goto probe_exit; 332 } 333 334 phy->i2c_dev = client; 335 i2c_set_clientdata(client, phy); 336 337 pdata = client->dev.platform_data; 338 339 if (!pdata && client->dev.of_node) { 340 r = nxp_nci_i2c_parse_devtree(client); 341 if (r < 0) { 342 nfc_err(&client->dev, "Failed to get DT data\n"); 343 goto probe_exit; 344 } 345 } else if (pdata) { 346 phy->gpio_en = pdata->gpio_en; 347 phy->gpio_fw = pdata->gpio_fw; 348 } else if (ACPI_HANDLE(&client->dev)) { 349 r = nxp_nci_i2c_acpi_config(phy); 350 if (r < 0) 351 goto probe_exit; 352 goto nci_probe; 353 } else { 354 nfc_err(&client->dev, "No platform data\n"); 355 r = -EINVAL; 356 goto probe_exit; 357 } 358 359 r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en, 360 GPIOF_OUT_INIT_LOW, "nxp_nci_en"); 361 if (r < 0) 362 goto probe_exit; 363 364 r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw, 365 GPIOF_OUT_INIT_LOW, "nxp_nci_fw"); 366 if (r < 0) 367 goto probe_exit; 368 369 nci_probe: 370 r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops, 371 NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev); 372 if (r < 0) 373 goto probe_exit; 374 375 r = request_threaded_irq(client->irq, NULL, 376 nxp_nci_i2c_irq_thread_fn, 377 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 378 NXP_NCI_I2C_DRIVER_NAME, phy); 379 if (r < 0) 380 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 381 382 probe_exit: 383 return r; 384 } 385 386 static int nxp_nci_i2c_remove(struct i2c_client *client) 387 { 388 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client); 389 390 nxp_nci_remove(phy->ndev); 391 free_irq(client->irq, phy); 392 393 return 0; 394 } 395 396 static const struct i2c_device_id nxp_nci_i2c_id_table[] = { 397 {"nxp-nci_i2c", 0}, 398 {} 399 }; 400 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table); 401 402 static const struct of_device_id of_nxp_nci_i2c_match[] = { 403 { .compatible = "nxp,nxp-nci-i2c", }, 404 {}, 405 }; 406 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match); 407 408 #ifdef CONFIG_ACPI 409 static struct acpi_device_id acpi_id[] = { 410 { "NXP7471" }, 411 { }, 412 }; 413 MODULE_DEVICE_TABLE(acpi, acpi_id); 414 #endif 415 416 static struct i2c_driver nxp_nci_i2c_driver = { 417 .driver = { 418 .name = NXP_NCI_I2C_DRIVER_NAME, 419 .acpi_match_table = ACPI_PTR(acpi_id), 420 .of_match_table = of_match_ptr(of_nxp_nci_i2c_match), 421 }, 422 .probe = nxp_nci_i2c_probe, 423 .id_table = nxp_nci_i2c_id_table, 424 .remove = nxp_nci_i2c_remove, 425 }; 426 427 module_i2c_driver(nxp_nci_i2c_driver); 428 429 MODULE_LICENSE("GPL"); 430 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers"); 431 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>"); 432 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>"); 433