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