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 "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 struct gpio_desc *gpiod_reset; 215 struct device *dev = &client->dev; 216 u8 tmp; 217 218 /* Get RESET GPIO from ACPI */ 219 gpiod_reset = devm_gpiod_get_index(dev, ST_NCI_GPIO_NAME_RESET, 1, 220 GPIOD_OUT_HIGH); 221 if (IS_ERR(gpiod_reset)) { 222 nfc_err(dev, "Unable to get RESET GPIO\n"); 223 return -ENODEV; 224 } 225 226 phy->gpio_reset = desc_to_gpio(gpiod_reset); 227 228 phy->irq_polarity = irq_get_trigger_type(client->irq); 229 230 phy->se_status.is_ese_present = false; 231 phy->se_status.is_uicc_present = false; 232 233 if (device_property_present(dev, "ese-present")) { 234 device_property_read_u8(dev, "ese-present", &tmp); 235 phy->se_status.is_ese_present = tmp; 236 } 237 238 if (device_property_present(dev, "uicc-present")) { 239 device_property_read_u8(dev, "uicc-present", &tmp); 240 phy->se_status.is_uicc_present = tmp; 241 } 242 243 return 0; 244 } 245 246 static int st_nci_i2c_of_request_resources(struct i2c_client *client) 247 { 248 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 249 struct device_node *pp; 250 int gpio; 251 int r; 252 253 pp = client->dev.of_node; 254 if (!pp) 255 return -ENODEV; 256 257 /* Get GPIO from device tree */ 258 gpio = of_get_named_gpio(pp, "reset-gpios", 0); 259 if (gpio < 0) { 260 nfc_err(&client->dev, 261 "Failed to retrieve reset-gpios from device tree\n"); 262 return gpio; 263 } 264 265 /* GPIO request and configuration */ 266 r = devm_gpio_request_one(&client->dev, gpio, 267 GPIOF_OUT_INIT_HIGH, ST_NCI_GPIO_NAME_RESET); 268 if (r) { 269 nfc_err(&client->dev, "Failed to request reset pin\n"); 270 return r; 271 } 272 phy->gpio_reset = gpio; 273 274 phy->irq_polarity = irq_get_trigger_type(client->irq); 275 276 phy->se_status.is_ese_present = 277 of_property_read_bool(pp, "ese-present"); 278 phy->se_status.is_uicc_present = 279 of_property_read_bool(pp, "uicc-present"); 280 281 return 0; 282 } 283 284 static int st_nci_i2c_request_resources(struct i2c_client *client) 285 { 286 struct st_nci_nfc_platform_data *pdata; 287 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 288 int r; 289 290 pdata = client->dev.platform_data; 291 if (pdata == NULL) { 292 nfc_err(&client->dev, "No platform data\n"); 293 return -EINVAL; 294 } 295 296 /* store for later use */ 297 phy->gpio_reset = pdata->gpio_reset; 298 phy->irq_polarity = pdata->irq_polarity; 299 300 r = devm_gpio_request_one(&client->dev, 301 phy->gpio_reset, GPIOF_OUT_INIT_HIGH, 302 ST_NCI_GPIO_NAME_RESET); 303 if (r) { 304 pr_err("%s : reset gpio_request failed\n", __FILE__); 305 return r; 306 } 307 308 phy->se_status.is_ese_present = pdata->is_ese_present; 309 phy->se_status.is_uicc_present = pdata->is_uicc_present; 310 311 return 0; 312 } 313 314 static int st_nci_i2c_probe(struct i2c_client *client, 315 const struct i2c_device_id *id) 316 { 317 struct st_nci_i2c_phy *phy; 318 struct st_nci_nfc_platform_data *pdata; 319 int r; 320 321 dev_dbg(&client->dev, "%s\n", __func__); 322 dev_dbg(&client->dev, "IRQ: %d\n", client->irq); 323 324 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 325 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); 326 return -ENODEV; 327 } 328 329 phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy), 330 GFP_KERNEL); 331 if (!phy) 332 return -ENOMEM; 333 334 phy->i2c_dev = client; 335 336 i2c_set_clientdata(client, phy); 337 338 pdata = client->dev.platform_data; 339 if (!pdata && client->dev.of_node) { 340 r = st_nci_i2c_of_request_resources(client); 341 if (r) { 342 nfc_err(&client->dev, "No platform data\n"); 343 return r; 344 } 345 } else if (pdata) { 346 r = st_nci_i2c_request_resources(client); 347 if (r) { 348 nfc_err(&client->dev, 349 "Cannot get platform resources\n"); 350 return r; 351 } 352 } else if (ACPI_HANDLE(&client->dev)) { 353 r = st_nci_i2c_acpi_request_resources(client); 354 if (r) { 355 nfc_err(&client->dev, "Cannot get ACPI data\n"); 356 return r; 357 } 358 } else { 359 nfc_err(&client->dev, 360 "st_nci platform resources not available\n"); 361 return -ENODEV; 362 } 363 364 r = ndlc_probe(phy, &i2c_phy_ops, &client->dev, 365 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM, 366 &phy->ndlc, &phy->se_status); 367 if (r < 0) { 368 nfc_err(&client->dev, "Unable to register ndlc layer\n"); 369 return r; 370 } 371 372 phy->irq_active = true; 373 r = devm_request_threaded_irq(&client->dev, client->irq, NULL, 374 st_nci_irq_thread_fn, 375 phy->irq_polarity | IRQF_ONESHOT, 376 ST_NCI_DRIVER_NAME, phy); 377 if (r < 0) 378 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 379 380 return r; 381 } 382 383 static int st_nci_i2c_remove(struct i2c_client *client) 384 { 385 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); 386 387 dev_dbg(&client->dev, "%s\n", __func__); 388 389 ndlc_remove(phy->ndlc); 390 391 return 0; 392 } 393 394 static struct i2c_device_id st_nci_i2c_id_table[] = { 395 {ST_NCI_DRIVER_NAME, 0}, 396 {} 397 }; 398 MODULE_DEVICE_TABLE(i2c, st_nci_i2c_id_table); 399 400 static const struct acpi_device_id st_nci_i2c_acpi_match[] = { 401 {"SMO2101"}, 402 {"SMO2102"}, 403 {} 404 }; 405 MODULE_DEVICE_TABLE(acpi, st_nci_i2c_acpi_match); 406 407 static const struct of_device_id of_st_nci_i2c_match[] = { 408 { .compatible = "st,st21nfcb-i2c", }, 409 { .compatible = "st,st21nfcb_i2c", }, 410 { .compatible = "st,st21nfcc-i2c", }, 411 {} 412 }; 413 MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match); 414 415 static struct i2c_driver st_nci_i2c_driver = { 416 .driver = { 417 .name = ST_NCI_I2C_DRIVER_NAME, 418 .of_match_table = of_match_ptr(of_st_nci_i2c_match), 419 .acpi_match_table = ACPI_PTR(st_nci_i2c_acpi_match), 420 }, 421 .probe = st_nci_i2c_probe, 422 .id_table = st_nci_i2c_id_table, 423 .remove = st_nci_i2c_remove, 424 }; 425 module_i2c_driver(st_nci_i2c_driver); 426 427 MODULE_LICENSE("GPL"); 428 MODULE_DESCRIPTION(DRIVER_DESC); 429