1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* ------------------------------------------------------------------------- 3 * Copyright (C) 2014-2016, Intel Corporation 4 * 5 * ------------------------------------------------------------------------- 6 */ 7 8 #include <linux/module.h> 9 #include <linux/acpi.h> 10 #include <linux/i2c.h> 11 #include <linux/interrupt.h> 12 #include <linux/nfc.h> 13 #include <linux/delay.h> 14 #include <linux/gpio/consumer.h> 15 #include <net/nfc/nfc.h> 16 #include <net/nfc/nci_core.h> 17 18 #include "fdp.h" 19 20 #define FDP_I2C_DRIVER_NAME "fdp_nci_i2c" 21 22 #define FDP_DP_CLOCK_TYPE_NAME "clock-type" 23 #define FDP_DP_CLOCK_FREQ_NAME "clock-freq" 24 #define FDP_DP_FW_VSC_CFG_NAME "fw-vsc-cfg" 25 26 #define FDP_FRAME_HEADROOM 2 27 #define FDP_FRAME_TAILROOM 1 28 29 #define FDP_NCI_I2C_MIN_PAYLOAD 5 30 #define FDP_NCI_I2C_MAX_PAYLOAD 261 31 32 #define FDP_POWER_OFF 0 33 #define FDP_POWER_ON 1 34 35 #define fdp_nci_i2c_dump_skb(dev, prefix, skb) \ 36 print_hex_dump(KERN_DEBUG, prefix": ", DUMP_PREFIX_OFFSET, \ 37 16, 1, (skb)->data, (skb)->len, 0) 38 39 static void fdp_nci_i2c_reset(struct fdp_i2c_phy *phy) 40 { 41 /* Reset RST/WakeUP for at least 100 micro-second */ 42 gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_OFF); 43 usleep_range(1000, 4000); 44 gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_ON); 45 usleep_range(10000, 14000); 46 } 47 48 static int fdp_nci_i2c_enable(void *phy_id) 49 { 50 struct fdp_i2c_phy *phy = phy_id; 51 52 dev_dbg(&phy->i2c_dev->dev, "%s\n", __func__); 53 fdp_nci_i2c_reset(phy); 54 55 return 0; 56 } 57 58 static void fdp_nci_i2c_disable(void *phy_id) 59 { 60 struct fdp_i2c_phy *phy = phy_id; 61 62 dev_dbg(&phy->i2c_dev->dev, "%s\n", __func__); 63 fdp_nci_i2c_reset(phy); 64 } 65 66 static void fdp_nci_i2c_add_len_lrc(struct sk_buff *skb) 67 { 68 u8 lrc = 0; 69 u16 len, i; 70 71 /* Add length header */ 72 len = skb->len; 73 *(u8 *)skb_push(skb, 1) = len & 0xff; 74 *(u8 *)skb_push(skb, 1) = len >> 8; 75 76 /* Compute and add lrc */ 77 for (i = 0; i < len + 2; i++) 78 lrc ^= skb->data[i]; 79 80 skb_put_u8(skb, lrc); 81 } 82 83 static void fdp_nci_i2c_remove_len_lrc(struct sk_buff *skb) 84 { 85 skb_pull(skb, FDP_FRAME_HEADROOM); 86 skb_trim(skb, skb->len - FDP_FRAME_TAILROOM); 87 } 88 89 static int fdp_nci_i2c_write(void *phy_id, struct sk_buff *skb) 90 { 91 struct fdp_i2c_phy *phy = phy_id; 92 struct i2c_client *client = phy->i2c_dev; 93 int r; 94 95 if (phy->hard_fault != 0) 96 return phy->hard_fault; 97 98 fdp_nci_i2c_add_len_lrc(skb); 99 fdp_nci_i2c_dump_skb(&client->dev, "fdp_wr", skb); 100 101 r = i2c_master_send(client, skb->data, skb->len); 102 if (r == -EREMOTEIO) { /* Retry, chip was in standby */ 103 usleep_range(1000, 4000); 104 r = i2c_master_send(client, skb->data, skb->len); 105 } 106 107 if (r < 0 || r != skb->len) 108 dev_dbg(&client->dev, "%s: error err=%d len=%d\n", 109 __func__, r, skb->len); 110 111 if (r >= 0) { 112 if (r != skb->len) { 113 phy->hard_fault = r; 114 r = -EREMOTEIO; 115 } else { 116 r = 0; 117 } 118 } 119 120 fdp_nci_i2c_remove_len_lrc(skb); 121 122 return r; 123 } 124 125 static struct nfc_phy_ops i2c_phy_ops = { 126 .write = fdp_nci_i2c_write, 127 .enable = fdp_nci_i2c_enable, 128 .disable = fdp_nci_i2c_disable, 129 }; 130 131 static int fdp_nci_i2c_read(struct fdp_i2c_phy *phy, struct sk_buff **skb) 132 { 133 int r, len; 134 u8 tmp[FDP_NCI_I2C_MAX_PAYLOAD], lrc, k; 135 u16 i; 136 struct i2c_client *client = phy->i2c_dev; 137 138 *skb = NULL; 139 140 /* Read the length packet and the data packet */ 141 for (k = 0; k < 2; k++) { 142 143 len = phy->next_read_size; 144 145 r = i2c_master_recv(client, tmp, len); 146 if (r != len) { 147 dev_dbg(&client->dev, "%s: i2c recv err: %d\n", 148 __func__, r); 149 goto flush; 150 } 151 152 /* Check packet integruty */ 153 for (lrc = i = 0; i < r; i++) 154 lrc ^= tmp[i]; 155 156 /* 157 * LRC check failed. This may due to transmission error or 158 * desynchronization between driver and FDP. Drop the paquet 159 * and force resynchronization 160 */ 161 if (lrc) { 162 dev_dbg(&client->dev, "%s: corrupted packet\n", 163 __func__); 164 phy->next_read_size = 5; 165 goto flush; 166 } 167 168 /* Packet that contains a length */ 169 if (tmp[0] == 0 && tmp[1] == 0) { 170 phy->next_read_size = (tmp[2] << 8) + tmp[3] + 3; 171 } else { 172 phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD; 173 174 *skb = alloc_skb(len, GFP_KERNEL); 175 if (*skb == NULL) { 176 r = -ENOMEM; 177 goto flush; 178 } 179 180 skb_put_data(*skb, tmp, len); 181 fdp_nci_i2c_dump_skb(&client->dev, "fdp_rd", *skb); 182 183 fdp_nci_i2c_remove_len_lrc(*skb); 184 } 185 } 186 187 return 0; 188 189 flush: 190 /* Flush the remaining data */ 191 if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0) 192 r = -EREMOTEIO; 193 194 return r; 195 } 196 197 static irqreturn_t fdp_nci_i2c_irq_thread_fn(int irq, void *phy_id) 198 { 199 struct fdp_i2c_phy *phy = phy_id; 200 struct i2c_client *client; 201 struct sk_buff *skb; 202 int r; 203 204 if (!phy || irq != phy->i2c_dev->irq) { 205 WARN_ON_ONCE(1); 206 return IRQ_NONE; 207 } 208 209 client = phy->i2c_dev; 210 dev_dbg(&client->dev, "%s\n", __func__); 211 212 r = fdp_nci_i2c_read(phy, &skb); 213 214 if (r == -EREMOTEIO) 215 return IRQ_HANDLED; 216 else if (r == -ENOMEM || r == -EBADMSG) 217 return IRQ_HANDLED; 218 219 if (skb != NULL) 220 fdp_nci_recv_frame(phy->ndev, skb); 221 222 return IRQ_HANDLED; 223 } 224 225 static void fdp_nci_i2c_read_device_properties(struct device *dev, 226 u8 *clock_type, u32 *clock_freq, 227 u8 **fw_vsc_cfg) 228 { 229 int r; 230 u8 len; 231 232 r = device_property_read_u8(dev, FDP_DP_CLOCK_TYPE_NAME, clock_type); 233 if (r) { 234 dev_dbg(dev, "Using default clock type"); 235 *clock_type = 0; 236 } 237 238 r = device_property_read_u32(dev, FDP_DP_CLOCK_FREQ_NAME, clock_freq); 239 if (r) { 240 dev_dbg(dev, "Using default clock frequency\n"); 241 *clock_freq = 26000; 242 } 243 244 if (device_property_present(dev, FDP_DP_FW_VSC_CFG_NAME)) { 245 r = device_property_read_u8(dev, FDP_DP_FW_VSC_CFG_NAME, 246 &len); 247 248 if (r || len <= 0) 249 goto vsc_read_err; 250 251 /* Add 1 to the length to inclue the length byte itself */ 252 len++; 253 254 *fw_vsc_cfg = devm_kmalloc_array(dev, 255 len, sizeof(**fw_vsc_cfg), 256 GFP_KERNEL); 257 258 r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME, 259 *fw_vsc_cfg, len); 260 261 if (r) { 262 devm_kfree(dev, *fw_vsc_cfg); 263 goto vsc_read_err; 264 } 265 } else { 266 vsc_read_err: 267 dev_dbg(dev, "FW vendor specific commands not present\n"); 268 *fw_vsc_cfg = NULL; 269 } 270 271 dev_dbg(dev, "Clock type: %d, clock frequency: %d, VSC: %s", 272 *clock_type, *clock_freq, *fw_vsc_cfg != NULL ? "yes" : "no"); 273 } 274 275 static const struct acpi_gpio_params power_gpios = { 0, 0, false }; 276 277 static const struct acpi_gpio_mapping acpi_fdp_gpios[] = { 278 { "power-gpios", &power_gpios, 1 }, 279 {}, 280 }; 281 282 static int fdp_nci_i2c_probe(struct i2c_client *client) 283 { 284 struct fdp_i2c_phy *phy; 285 struct device *dev = &client->dev; 286 u8 *fw_vsc_cfg; 287 u8 clock_type; 288 u32 clock_freq; 289 int r = 0; 290 291 dev_dbg(dev, "%s\n", __func__); 292 293 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 294 nfc_err(dev, "No I2C_FUNC_I2C support\n"); 295 return -ENODEV; 296 } 297 298 /* Checking if we have an irq */ 299 if (client->irq <= 0) { 300 nfc_err(dev, "IRQ not present\n"); 301 return -ENODEV; 302 } 303 304 phy = devm_kzalloc(dev, sizeof(struct fdp_i2c_phy), GFP_KERNEL); 305 if (!phy) 306 return -ENOMEM; 307 308 phy->i2c_dev = client; 309 phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD; 310 i2c_set_clientdata(client, phy); 311 312 r = devm_request_threaded_irq(dev, client->irq, 313 NULL, fdp_nci_i2c_irq_thread_fn, 314 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 315 FDP_I2C_DRIVER_NAME, phy); 316 317 if (r < 0) { 318 nfc_err(&client->dev, "Unable to register IRQ handler\n"); 319 return r; 320 } 321 322 r = devm_acpi_dev_add_driver_gpios(dev, acpi_fdp_gpios); 323 if (r) 324 dev_dbg(dev, "Unable to add GPIO mapping table\n"); 325 326 /* Requesting the power gpio */ 327 phy->power_gpio = devm_gpiod_get(dev, "power", GPIOD_OUT_LOW); 328 if (IS_ERR(phy->power_gpio)) { 329 nfc_err(dev, "Power GPIO request failed\n"); 330 return PTR_ERR(phy->power_gpio); 331 } 332 333 /* read device properties to get the clock and production settings */ 334 fdp_nci_i2c_read_device_properties(dev, &clock_type, &clock_freq, 335 &fw_vsc_cfg); 336 337 /* Call the NFC specific probe function */ 338 r = fdp_nci_probe(phy, &i2c_phy_ops, &phy->ndev, 339 FDP_FRAME_HEADROOM, FDP_FRAME_TAILROOM, 340 clock_type, clock_freq, fw_vsc_cfg); 341 if (r < 0) { 342 nfc_err(dev, "NCI probing error\n"); 343 return r; 344 } 345 346 dev_dbg(dev, "I2C driver loaded\n"); 347 return 0; 348 } 349 350 static int fdp_nci_i2c_remove(struct i2c_client *client) 351 { 352 struct fdp_i2c_phy *phy = i2c_get_clientdata(client); 353 354 dev_dbg(&client->dev, "%s\n", __func__); 355 356 fdp_nci_remove(phy->ndev); 357 fdp_nci_i2c_disable(phy); 358 359 return 0; 360 } 361 362 static const struct acpi_device_id fdp_nci_i2c_acpi_match[] = { 363 {"INT339A", 0}, 364 {} 365 }; 366 MODULE_DEVICE_TABLE(acpi, fdp_nci_i2c_acpi_match); 367 368 static struct i2c_driver fdp_nci_i2c_driver = { 369 .driver = { 370 .name = FDP_I2C_DRIVER_NAME, 371 .acpi_match_table = ACPI_PTR(fdp_nci_i2c_acpi_match), 372 }, 373 .probe_new = fdp_nci_i2c_probe, 374 .remove = fdp_nci_i2c_remove, 375 }; 376 module_i2c_driver(fdp_nci_i2c_driver); 377 378 MODULE_LICENSE("GPL"); 379 MODULE_DESCRIPTION("I2C driver for Intel Fields Peak NFC controller"); 380 MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>"); 381