1 /* 2 * I2C Link Layer for ST NCI NFC controller familly based Driver 3 * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved. 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms and conditions of the GNU General Public License, 7 * version 2, as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 19 20 #include <linux/module.h> 21 #include <linux/i2c.h> 22 #include <linux/gpio.h> 23 #include <linux/gpio/consumer.h> 24 #include <linux/of_irq.h> 25 #include <linux/of_gpio.h> 26 #include <linux/acpi.h> 27 #include <linux/interrupt.h> 28 #include <linux/delay.h> 29 #include <linux/nfc.h> 30 #include <linux/platform_data/st-nci.h> 31 32 #include "st-nci.h" 33 34 #define DRIVER_DESC "NCI NFC driver for ST_NCI" 35 36 /* ndlc header */ 37 #define ST_NCI_FRAME_HEADROOM 1 38 #define ST_NCI_FRAME_TAILROOM 0 39 40 #define ST_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */ 41 #define ST_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */ 42 43 #define ST_NCI_I2C_DRIVER_NAME "st_nci_i2c" 44 45 #define ST_NCI_GPIO_NAME_RESET "clf_reset" 46 47 struct st_nci_i2c_phy { 48 struct i2c_client *i2c_dev; 49 struct llt_ndlc *ndlc; 50 51 bool irq_active; 52 53 unsigned int gpio_reset; 54 unsigned int irq_polarity; 55 56 struct st_nci_se_status se_status; 57 }; 58 59 static int st_nci_i2c_enable(void *phy_id) 60 { 61 struct st_nci_i2c_phy *phy = phy_id; 62 63 gpio_set_value(phy->gpio_reset, 0); 64 usleep_range(10000, 15000); 65 gpio_set_value(phy->gpio_reset, 1); 66 usleep_range(80000, 85000); 67 68 if (phy->ndlc->powered == 0 && phy->irq_active == 0) { 69 enable_irq(phy->i2c_dev->irq); 70 phy->irq_active = true; 71 } 72 73 return 0; 74 } 75 76 static void st_nci_i2c_disable(void *phy_id) 77 { 78 struct st_nci_i2c_phy *phy = phy_id; 79 80 disable_irq_nosync(phy->i2c_dev->irq); 81 phy->irq_active = false; 82 } 83 84 /* 85 * Writing a frame must not return the number of written bytes. 86 * It must return either zero for success, or <0 for error. 87 * In addition, it must not alter the skb 88 */ 89 static int st_nci_i2c_write(void *phy_id, struct sk_buff *skb) 90 { 91 int r = -1; 92 struct st_nci_i2c_phy *phy = phy_id; 93 struct i2c_client *client = phy->i2c_dev; 94 95 if (phy->ndlc->hard_fault != 0) 96 return phy->ndlc->hard_fault; 97 98 r = i2c_master_send(client, skb->data, skb->len); 99 if (r < 0) { /* Retry, chip was in standby */ 100 usleep_range(1000, 4000); 101 r = i2c_master_send(client, skb->data, skb->len); 102 } 103 104 if (r >= 0) { 105 if (r != skb->len) 106 r = -EREMOTEIO; 107 else 108 r = 0; 109 } 110 111 return r; 112 } 113 114 /* 115 * Reads an ndlc frame and returns it in a newly allocated sk_buff. 116 * returns: 117 * 0 : if received frame is complete 118 * -EREMOTEIO : i2c read error (fatal) 119 * -EBADMSG : frame was incorrect and discarded 120 * -ENOMEM : cannot allocate skb, frame dropped 121 */ 122 static int st_nci_i2c_read(struct st_nci_i2c_phy *phy, 123 struct sk_buff **skb) 124 { 125 int r; 126 u8 len; 127 u8 buf[ST_NCI_I2C_MAX_SIZE]; 128 struct i2c_client *client = phy->i2c_dev; 129 130 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE); 131 if (r < 0) { /* Retry, chip was in standby */ 132 usleep_range(1000, 4000); 133 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE); 134 } 135 136 if (r != ST_NCI_I2C_MIN_SIZE) 137 return -EREMOTEIO; 138 139 len = be16_to_cpu(*(__be16 *) (buf + 2)); 140 if (len > ST_NCI_I2C_MAX_SIZE) { 141 nfc_err(&client->dev, "invalid frame len\n"); 142 return -EBADMSG; 143 } 144 145 *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL); 146 if (*skb == NULL) 147 return -ENOMEM; 148 149 skb_reserve(*skb, ST_NCI_I2C_MIN_SIZE); 150 skb_put(*skb, ST_NCI_I2C_MIN_SIZE); 151 memcpy((*skb)->data, buf, ST_NCI_I2C_MIN_SIZE); 152 153 if (!len) 154 return 0; 155 156 r = i2c_master_recv(client, buf, len); 157 if (r != len) { 158 kfree_skb(*skb); 159 return -EREMOTEIO; 160 } 161 162 skb_put(*skb, len); 163 memcpy((*skb)->data + ST_NCI_I2C_MIN_SIZE, buf, len); 164 165 return 0; 166 } 167 168 /* 169 * Reads an ndlc frame from the chip. 170 * 171 * On ST_NCI, IRQ goes in idle state when read starts. 172 */ 173 static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id) 174 { 175 struct st_nci_i2c_phy *phy = phy_id; 176 struct i2c_client *client; 177 struct sk_buff *skb = NULL; 178 int r; 179 180 if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) { 181 WARN_ON_ONCE(1); 182 return IRQ_NONE; 183 } 184 185 client = phy->i2c_dev; 186 dev_dbg(&client->dev, "IRQ\n"); 187 188 if (phy->ndlc->hard_fault) 189 return IRQ_HANDLED; 190 191 if (!phy->ndlc->powered) { 192 st_nci_i2c_disable(phy); 193 return IRQ_HANDLED; 194 } 195 196 r = st_nci_i2c_read(phy, &skb); 197 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG) 198 return IRQ_HANDLED; 199 200 ndlc_recv(phy->ndlc, skb); 201 202 return IRQ_HANDLED; 203 } 204 205 static struct nfc_phy_ops i2c_phy_ops = { 206 .write = st_nci_i2c_write, 207 .enable = st_nci_i2c_enable, 208 .disable = st_nci_i2c_disable, 209 }; 210 211 static int st_nci_i2c_acpi_request_resources(struct i2c_client *client) 212 { 213 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 214 const struct acpi_device_id *id; 215 struct gpio_desc *gpiod_reset; 216 struct device *dev; 217 218 if (!client) 219 return -EINVAL; 220 221 dev = &client->dev; 222 223 /* Match the struct device against a given list of ACPI IDs */ 224 id = acpi_match_device(dev->driver->acpi_match_table, dev); 225 if (!id) 226 return -ENODEV; 227 228 /* Get RESET GPIO from ACPI */ 229 gpiod_reset = devm_gpiod_get_index(dev, ST_NCI_GPIO_NAME_RESET, 1, 230 GPIOD_OUT_HIGH); 231 if (IS_ERR(gpiod_reset)) { 232 nfc_err(dev, "Unable to get RESET GPIO\n"); 233 return -ENODEV; 234 } 235 236 phy->gpio_reset = desc_to_gpio(gpiod_reset); 237 238 phy->irq_polarity = irq_get_trigger_type(client->irq); 239 240 phy->se_status.is_ese_present = 241 device_property_present(dev, "ese-present"); 242 phy->se_status.is_uicc_present = 243 device_property_present(dev, "uicc-present"); 244 245 return 0; 246 } 247 248 static int st_nci_i2c_of_request_resources(struct i2c_client *client) 249 { 250 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 251 struct device_node *pp; 252 int gpio; 253 int r; 254 255 pp = client->dev.of_node; 256 if (!pp) 257 return -ENODEV; 258 259 /* Get GPIO from device tree */ 260 gpio = of_get_named_gpio(pp, "reset-gpios", 0); 261 if (gpio < 0) { 262 nfc_err(&client->dev, 263 "Failed to retrieve reset-gpios from device tree\n"); 264 return gpio; 265 } 266 267 /* GPIO request and configuration */ 268 r = devm_gpio_request_one(&client->dev, gpio, 269 GPIOF_OUT_INIT_HIGH, ST_NCI_GPIO_NAME_RESET); 270 if (r) { 271 nfc_err(&client->dev, "Failed to request reset pin\n"); 272 return r; 273 } 274 phy->gpio_reset = gpio; 275 276 phy->irq_polarity = irq_get_trigger_type(client->irq); 277 278 phy->se_status.is_ese_present = 279 of_property_read_bool(pp, "ese-present"); 280 phy->se_status.is_uicc_present = 281 of_property_read_bool(pp, "uicc-present"); 282 283 return 0; 284 } 285 286 static int st_nci_i2c_request_resources(struct i2c_client *client) 287 { 288 struct st_nci_nfc_platform_data *pdata; 289 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 290 int r; 291 292 pdata = client->dev.platform_data; 293 if (pdata == NULL) { 294 nfc_err(&client->dev, "No platform data\n"); 295 return -EINVAL; 296 } 297 298 /* store for later use */ 299 phy->gpio_reset = pdata->gpio_reset; 300 phy->irq_polarity = pdata->irq_polarity; 301 302 r = devm_gpio_request_one(&client->dev, 303 phy->gpio_reset, GPIOF_OUT_INIT_HIGH, 304 ST_NCI_GPIO_NAME_RESET); 305 if (r) { 306 pr_err("%s : reset gpio_request failed\n", __FILE__); 307 return r; 308 } 309 310 phy->se_status.is_ese_present = pdata->is_ese_present; 311 phy->se_status.is_uicc_present = pdata->is_uicc_present; 312 313 return 0; 314 } 315 316 static int st_nci_i2c_probe(struct i2c_client *client, 317 const struct i2c_device_id *id) 318 { 319 struct st_nci_i2c_phy *phy; 320 struct st_nci_nfc_platform_data *pdata; 321 int r; 322 323 dev_dbg(&client->dev, "%s\n", __func__); 324 dev_dbg(&client->dev, "IRQ: %d\n", client->irq); 325 326 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 327 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 328 return -ENODEV; 329 } 330 331 phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy), 332 GFP_KERNEL); 333 if (!phy) 334 return -ENOMEM; 335 336 phy->i2c_dev = client; 337 338 i2c_set_clientdata(client, phy); 339 340 pdata = client->dev.platform_data; 341 if (!pdata && client->dev.of_node) { 342 r = st_nci_i2c_of_request_resources(client); 343 if (r) { 344 nfc_err(&client->dev, "No platform data\n"); 345 return r; 346 } 347 } else if (pdata) { 348 r = st_nci_i2c_request_resources(client); 349 if (r) { 350 nfc_err(&client->dev, 351 "Cannot get platform resources\n"); 352 return r; 353 } 354 } else if (ACPI_HANDLE(&client->dev)) { 355 r = st_nci_i2c_acpi_request_resources(client); 356 if (r) { 357 nfc_err(&client->dev, "Cannot get ACPI data\n"); 358 return r; 359 } 360 } else { 361 nfc_err(&client->dev, 362 "st_nci platform resources not available\n"); 363 return -ENODEV; 364 } 365 366 r = ndlc_probe(phy, &i2c_phy_ops, &client->dev, 367 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM, 368 &phy->ndlc, &phy->se_status); 369 if (r < 0) { 370 nfc_err(&client->dev, "Unable to register ndlc layer\n"); 371 return r; 372 } 373 374 phy->irq_active = true; 375 r = devm_request_threaded_irq(&client->dev, client->irq, NULL, 376 st_nci_irq_thread_fn, 377 phy->irq_polarity | IRQF_ONESHOT, 378 ST_NCI_DRIVER_NAME, phy); 379 if (r < 0) 380 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 381 382 return r; 383 } 384 385 static int st_nci_i2c_remove(struct i2c_client *client) 386 { 387 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 388 389 dev_dbg(&client->dev, "%s\n", __func__); 390 391 ndlc_remove(phy->ndlc); 392 393 return 0; 394 } 395 396 static struct i2c_device_id st_nci_i2c_id_table[] = { 397 {ST_NCI_DRIVER_NAME, 0}, 398 {} 399 }; 400 MODULE_DEVICE_TABLE(i2c, st_nci_i2c_id_table); 401 402 static const struct acpi_device_id st_nci_i2c_acpi_match[] = { 403 {"SMO2101"}, 404 {"SMO2102"}, 405 {} 406 }; 407 MODULE_DEVICE_TABLE(acpi, st_nci_i2c_acpi_match); 408 409 static const struct of_device_id of_st_nci_i2c_match[] = { 410 { .compatible = "st,st21nfcb-i2c", }, 411 { .compatible = "st,st21nfcb_i2c", }, 412 { .compatible = "st,st21nfcc-i2c", }, 413 {} 414 }; 415 MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match); 416 417 static struct i2c_driver st_nci_i2c_driver = { 418 .driver = { 419 .owner = THIS_MODULE, 420 .name = ST_NCI_I2C_DRIVER_NAME, 421 .of_match_table = of_match_ptr(of_st_nci_i2c_match), 422 .acpi_match_table = ACPI_PTR(st_nci_i2c_acpi_match), 423 }, 424 .probe = st_nci_i2c_probe, 425 .id_table = st_nci_i2c_id_table, 426 .remove = st_nci_i2c_remove, 427 }; 428 module_i2c_driver(st_nci_i2c_driver); 429 430 MODULE_LICENSE("GPL"); 431 MODULE_DESCRIPTION(DRIVER_DESC); 432