1 /* 2 * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge 3 * Copyright (c) 2013,2014 Uplogix, Inc. 4 * David Barksdale <dbarksdale@uplogix.com> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 */ 15 16 /* 17 * The Silicon Labs CP2112 chip is a USB HID device which provides an 18 * SMBus controller for talking to slave devices and 8 GPIO pins. The 19 * host communicates with the CP2112 via raw HID reports. 20 * 21 * Data Sheet: 22 * http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf 23 * Programming Interface Specification: 24 * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf 25 */ 26 27 #include <linux/gpio.h> 28 #include <linux/hid.h> 29 #include <linux/i2c.h> 30 #include <linux/module.h> 31 #include <linux/nls.h> 32 #include <linux/usb/ch9.h> 33 #include "hid-ids.h" 34 35 enum { 36 CP2112_GPIO_CONFIG = 0x02, 37 CP2112_GPIO_GET = 0x03, 38 CP2112_GPIO_SET = 0x04, 39 CP2112_GET_VERSION_INFO = 0x05, 40 CP2112_SMBUS_CONFIG = 0x06, 41 CP2112_DATA_READ_REQUEST = 0x10, 42 CP2112_DATA_WRITE_READ_REQUEST = 0x11, 43 CP2112_DATA_READ_FORCE_SEND = 0x12, 44 CP2112_DATA_READ_RESPONSE = 0x13, 45 CP2112_DATA_WRITE_REQUEST = 0x14, 46 CP2112_TRANSFER_STATUS_REQUEST = 0x15, 47 CP2112_TRANSFER_STATUS_RESPONSE = 0x16, 48 CP2112_CANCEL_TRANSFER = 0x17, 49 CP2112_LOCK_BYTE = 0x20, 50 CP2112_USB_CONFIG = 0x21, 51 CP2112_MANUFACTURER_STRING = 0x22, 52 CP2112_PRODUCT_STRING = 0x23, 53 CP2112_SERIAL_STRING = 0x24, 54 }; 55 56 enum { 57 STATUS0_IDLE = 0x00, 58 STATUS0_BUSY = 0x01, 59 STATUS0_COMPLETE = 0x02, 60 STATUS0_ERROR = 0x03, 61 }; 62 63 enum { 64 STATUS1_TIMEOUT_NACK = 0x00, 65 STATUS1_TIMEOUT_BUS = 0x01, 66 STATUS1_ARBITRATION_LOST = 0x02, 67 STATUS1_READ_INCOMPLETE = 0x03, 68 STATUS1_WRITE_INCOMPLETE = 0x04, 69 STATUS1_SUCCESS = 0x05, 70 }; 71 72 struct cp2112_smbus_config_report { 73 u8 report; /* CP2112_SMBUS_CONFIG */ 74 __be32 clock_speed; /* Hz */ 75 u8 device_address; /* Stored in the upper 7 bits */ 76 u8 auto_send_read; /* 1 = enabled, 0 = disabled */ 77 __be16 write_timeout; /* ms, 0 = no timeout */ 78 __be16 read_timeout; /* ms, 0 = no timeout */ 79 u8 scl_low_timeout; /* 1 = enabled, 0 = disabled */ 80 __be16 retry_time; /* # of retries, 0 = no limit */ 81 } __packed; 82 83 struct cp2112_usb_config_report { 84 u8 report; /* CP2112_USB_CONFIG */ 85 __le16 vid; /* Vendor ID */ 86 __le16 pid; /* Product ID */ 87 u8 max_power; /* Power requested in 2mA units */ 88 u8 power_mode; /* 0x00 = bus powered 89 0x01 = self powered & regulator off 90 0x02 = self powered & regulator on */ 91 u8 release_major; 92 u8 release_minor; 93 u8 mask; /* What fields to program */ 94 } __packed; 95 96 struct cp2112_read_req_report { 97 u8 report; /* CP2112_DATA_READ_REQUEST */ 98 u8 slave_address; 99 __be16 length; 100 } __packed; 101 102 struct cp2112_write_read_req_report { 103 u8 report; /* CP2112_DATA_WRITE_READ_REQUEST */ 104 u8 slave_address; 105 __be16 length; 106 u8 target_address_length; 107 u8 target_address[16]; 108 } __packed; 109 110 struct cp2112_write_req_report { 111 u8 report; /* CP2112_DATA_WRITE_REQUEST */ 112 u8 slave_address; 113 u8 length; 114 u8 data[61]; 115 } __packed; 116 117 struct cp2112_force_read_report { 118 u8 report; /* CP2112_DATA_READ_FORCE_SEND */ 119 __be16 length; 120 } __packed; 121 122 struct cp2112_xfer_status_report { 123 u8 report; /* CP2112_TRANSFER_STATUS_RESPONSE */ 124 u8 status0; /* STATUS0_* */ 125 u8 status1; /* STATUS1_* */ 126 __be16 retries; 127 __be16 length; 128 } __packed; 129 130 struct cp2112_string_report { 131 u8 dummy; /* force .string to be aligned */ 132 u8 report; /* CP2112_*_STRING */ 133 u8 length; /* length in bytes of everyting after .report */ 134 u8 type; /* USB_DT_STRING */ 135 wchar_t string[30]; /* UTF16_LITTLE_ENDIAN string */ 136 } __packed; 137 138 /* Number of times to request transfer status before giving up waiting for a 139 transfer to complete. This may need to be changed if SMBUS clock, retries, 140 or read/write/scl_low timeout settings are changed. */ 141 static const int XFER_STATUS_RETRIES = 10; 142 143 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or 144 CP2112_TRANSFER_STATUS_RESPONSE. */ 145 static const int RESPONSE_TIMEOUT = 50; 146 147 static const struct hid_device_id cp2112_devices[] = { 148 { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) }, 149 { } 150 }; 151 MODULE_DEVICE_TABLE(hid, cp2112_devices); 152 153 struct cp2112_device { 154 struct i2c_adapter adap; 155 struct hid_device *hdev; 156 wait_queue_head_t wait; 157 u8 read_data[61]; 158 u8 read_length; 159 int xfer_status; 160 atomic_t read_avail; 161 atomic_t xfer_avail; 162 struct gpio_chip gc; 163 }; 164 165 static int gpio_push_pull = 0xFF; 166 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR); 167 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask"); 168 169 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 170 { 171 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 172 gc); 173 struct hid_device *hdev = dev->hdev; 174 u8 buf[5]; 175 int ret; 176 177 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, 178 sizeof(buf), HID_FEATURE_REPORT, 179 HID_REQ_GET_REPORT); 180 if (ret != sizeof(buf)) { 181 hid_err(hdev, "error requesting GPIO config: %d\n", ret); 182 return ret; 183 } 184 185 buf[1] &= ~(1 << offset); 186 buf[2] = gpio_push_pull; 187 188 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), 189 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 190 if (ret < 0) { 191 hid_err(hdev, "error setting GPIO config: %d\n", ret); 192 return ret; 193 } 194 195 return 0; 196 } 197 198 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 199 { 200 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 201 gc); 202 struct hid_device *hdev = dev->hdev; 203 u8 buf[3]; 204 int ret; 205 206 buf[0] = CP2112_GPIO_SET; 207 buf[1] = value ? 0xff : 0; 208 buf[2] = 1 << offset; 209 210 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf), 211 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 212 if (ret < 0) 213 hid_err(hdev, "error setting GPIO values: %d\n", ret); 214 } 215 216 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset) 217 { 218 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 219 gc); 220 struct hid_device *hdev = dev->hdev; 221 u8 buf[2]; 222 int ret; 223 224 ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf), 225 HID_FEATURE_REPORT, HID_REQ_GET_REPORT); 226 if (ret != sizeof(buf)) { 227 hid_err(hdev, "error requesting GPIO values: %d\n", ret); 228 return ret; 229 } 230 231 return (buf[1] >> offset) & 1; 232 } 233 234 static int cp2112_gpio_direction_output(struct gpio_chip *chip, 235 unsigned offset, int value) 236 { 237 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 238 gc); 239 struct hid_device *hdev = dev->hdev; 240 u8 buf[5]; 241 int ret; 242 243 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, 244 sizeof(buf), HID_FEATURE_REPORT, 245 HID_REQ_GET_REPORT); 246 if (ret != sizeof(buf)) { 247 hid_err(hdev, "error requesting GPIO config: %d\n", ret); 248 return ret; 249 } 250 251 buf[1] |= 1 << offset; 252 buf[2] = gpio_push_pull; 253 254 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), 255 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 256 if (ret < 0) { 257 hid_err(hdev, "error setting GPIO config: %d\n", ret); 258 return ret; 259 } 260 261 /* 262 * Set gpio value when output direction is already set, 263 * as specified in AN495, Rev. 0.2, cpt. 4.4 264 */ 265 cp2112_gpio_set(chip, offset, value); 266 267 return 0; 268 } 269 270 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number, 271 u8 *data, size_t count, unsigned char report_type) 272 { 273 u8 *buf; 274 int ret; 275 276 buf = kmalloc(count, GFP_KERNEL); 277 if (!buf) 278 return -ENOMEM; 279 280 ret = hid_hw_raw_request(hdev, report_number, buf, count, 281 report_type, HID_REQ_GET_REPORT); 282 memcpy(data, buf, count); 283 kfree(buf); 284 return ret; 285 } 286 287 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count, 288 unsigned char report_type) 289 { 290 u8 *buf; 291 int ret; 292 293 buf = kmemdup(data, count, GFP_KERNEL); 294 if (!buf) 295 return -ENOMEM; 296 297 if (report_type == HID_OUTPUT_REPORT) 298 ret = hid_hw_output_report(hdev, buf, count); 299 else 300 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type, 301 HID_REQ_SET_REPORT); 302 303 kfree(buf); 304 return ret; 305 } 306 307 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail) 308 { 309 int ret = 0; 310 311 /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a 312 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to 313 * come in cp2112_raw_event or timeout. There will only be one of these 314 * in flight at any one time. The timeout is extremely large and is a 315 * last resort if the CP2112 has died. If we do timeout we don't expect 316 * to receive the response which would cause data races, it's not like 317 * we can do anything about it anyway. 318 */ 319 ret = wait_event_interruptible_timeout(dev->wait, 320 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT)); 321 if (-ERESTARTSYS == ret) 322 return ret; 323 if (!ret) 324 return -ETIMEDOUT; 325 326 atomic_set(avail, 0); 327 return 0; 328 } 329 330 static int cp2112_xfer_status(struct cp2112_device *dev) 331 { 332 struct hid_device *hdev = dev->hdev; 333 u8 buf[2]; 334 int ret; 335 336 buf[0] = CP2112_TRANSFER_STATUS_REQUEST; 337 buf[1] = 0x01; 338 atomic_set(&dev->xfer_avail, 0); 339 340 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); 341 if (ret < 0) { 342 hid_warn(hdev, "Error requesting status: %d\n", ret); 343 return ret; 344 } 345 346 ret = cp2112_wait(dev, &dev->xfer_avail); 347 if (ret) 348 return ret; 349 350 return dev->xfer_status; 351 } 352 353 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size) 354 { 355 struct hid_device *hdev = dev->hdev; 356 struct cp2112_force_read_report report; 357 int ret; 358 359 report.report = CP2112_DATA_READ_FORCE_SEND; 360 report.length = cpu_to_be16(size); 361 362 atomic_set(&dev->read_avail, 0); 363 364 ret = cp2112_hid_output(hdev, &report.report, sizeof(report), 365 HID_OUTPUT_REPORT); 366 if (ret < 0) { 367 hid_warn(hdev, "Error requesting data: %d\n", ret); 368 return ret; 369 } 370 371 ret = cp2112_wait(dev, &dev->read_avail); 372 if (ret) 373 return ret; 374 375 hid_dbg(hdev, "read %d of %zd bytes requested\n", 376 dev->read_length, size); 377 378 if (size > dev->read_length) 379 size = dev->read_length; 380 381 memcpy(data, dev->read_data, size); 382 return dev->read_length; 383 } 384 385 static int cp2112_read_req(void *buf, u8 slave_address, u16 length) 386 { 387 struct cp2112_read_req_report *report = buf; 388 389 if (length < 1 || length > 512) 390 return -EINVAL; 391 392 report->report = CP2112_DATA_READ_REQUEST; 393 report->slave_address = slave_address << 1; 394 report->length = cpu_to_be16(length); 395 return sizeof(*report); 396 } 397 398 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length, 399 u8 command, u8 *data, u8 data_length) 400 { 401 struct cp2112_write_read_req_report *report = buf; 402 403 if (length < 1 || length > 512 404 || data_length > sizeof(report->target_address) - 1) 405 return -EINVAL; 406 407 report->report = CP2112_DATA_WRITE_READ_REQUEST; 408 report->slave_address = slave_address << 1; 409 report->length = cpu_to_be16(length); 410 report->target_address_length = data_length + 1; 411 report->target_address[0] = command; 412 memcpy(&report->target_address[1], data, data_length); 413 return data_length + 6; 414 } 415 416 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data, 417 u8 data_length) 418 { 419 struct cp2112_write_req_report *report = buf; 420 421 if (data_length > sizeof(report->data) - 1) 422 return -EINVAL; 423 424 report->report = CP2112_DATA_WRITE_REQUEST; 425 report->slave_address = slave_address << 1; 426 report->length = data_length + 1; 427 report->data[0] = command; 428 memcpy(&report->data[1], data, data_length); 429 return data_length + 4; 430 } 431 432 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data, 433 u8 data_length) 434 { 435 struct cp2112_write_req_report *report = buf; 436 437 if (data_length > sizeof(report->data)) 438 return -EINVAL; 439 440 report->report = CP2112_DATA_WRITE_REQUEST; 441 report->slave_address = slave_address << 1; 442 report->length = data_length; 443 memcpy(report->data, data, data_length); 444 return data_length + 3; 445 } 446 447 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 448 int num) 449 { 450 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; 451 struct hid_device *hdev = dev->hdev; 452 u8 buf[64]; 453 ssize_t count; 454 unsigned int retries; 455 int ret; 456 457 hid_dbg(hdev, "I2C %d messages\n", num); 458 459 if (num != 1) { 460 hid_err(hdev, 461 "Multi-message I2C transactions not supported\n"); 462 return -EOPNOTSUPP; 463 } 464 465 if (msgs->flags & I2C_M_RD) 466 count = cp2112_read_req(buf, msgs->addr, msgs->len); 467 else 468 count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf, 469 msgs->len); 470 471 if (count < 0) 472 return count; 473 474 ret = hid_hw_power(hdev, PM_HINT_FULLON); 475 if (ret < 0) { 476 hid_err(hdev, "power management error: %d\n", ret); 477 return ret; 478 } 479 480 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); 481 if (ret < 0) { 482 hid_warn(hdev, "Error starting transaction: %d\n", ret); 483 goto power_normal; 484 } 485 486 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { 487 ret = cp2112_xfer_status(dev); 488 if (-EBUSY == ret) 489 continue; 490 if (ret < 0) 491 goto power_normal; 492 break; 493 } 494 495 if (XFER_STATUS_RETRIES <= retries) { 496 hid_warn(hdev, "Transfer timed out, cancelling.\n"); 497 buf[0] = CP2112_CANCEL_TRANSFER; 498 buf[1] = 0x01; 499 500 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); 501 if (ret < 0) 502 hid_warn(hdev, "Error cancelling transaction: %d\n", 503 ret); 504 505 ret = -ETIMEDOUT; 506 goto power_normal; 507 } 508 509 if (!(msgs->flags & I2C_M_RD)) 510 goto finish; 511 512 ret = cp2112_read(dev, msgs->buf, msgs->len); 513 if (ret < 0) 514 goto power_normal; 515 if (ret != msgs->len) { 516 hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len); 517 ret = -EIO; 518 goto power_normal; 519 } 520 521 finish: 522 /* return the number of transferred messages */ 523 ret = 1; 524 525 power_normal: 526 hid_hw_power(hdev, PM_HINT_NORMAL); 527 hid_dbg(hdev, "I2C transfer finished: %d\n", ret); 528 return ret; 529 } 530 531 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, 532 unsigned short flags, char read_write, u8 command, 533 int size, union i2c_smbus_data *data) 534 { 535 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; 536 struct hid_device *hdev = dev->hdev; 537 u8 buf[64]; 538 __be16 word; 539 ssize_t count; 540 size_t read_length = 0; 541 unsigned int retries; 542 int ret; 543 544 hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n", 545 read_write == I2C_SMBUS_WRITE ? "write" : "read", 546 addr, flags, command, size); 547 548 switch (size) { 549 case I2C_SMBUS_BYTE: 550 read_length = 1; 551 552 if (I2C_SMBUS_READ == read_write) 553 count = cp2112_read_req(buf, addr, read_length); 554 else 555 count = cp2112_write_req(buf, addr, data->byte, NULL, 556 0); 557 break; 558 case I2C_SMBUS_BYTE_DATA: 559 read_length = 1; 560 561 if (I2C_SMBUS_READ == read_write) 562 count = cp2112_write_read_req(buf, addr, read_length, 563 command, NULL, 0); 564 else 565 count = cp2112_write_req(buf, addr, command, 566 &data->byte, 1); 567 break; 568 case I2C_SMBUS_WORD_DATA: 569 read_length = 2; 570 word = cpu_to_be16(data->word); 571 572 if (I2C_SMBUS_READ == read_write) 573 count = cp2112_write_read_req(buf, addr, read_length, 574 command, NULL, 0); 575 else 576 count = cp2112_write_req(buf, addr, command, 577 (u8 *)&word, 2); 578 break; 579 case I2C_SMBUS_PROC_CALL: 580 size = I2C_SMBUS_WORD_DATA; 581 read_write = I2C_SMBUS_READ; 582 read_length = 2; 583 word = cpu_to_be16(data->word); 584 585 count = cp2112_write_read_req(buf, addr, read_length, command, 586 (u8 *)&word, 2); 587 break; 588 case I2C_SMBUS_I2C_BLOCK_DATA: 589 size = I2C_SMBUS_BLOCK_DATA; 590 /* fallthrough */ 591 case I2C_SMBUS_BLOCK_DATA: 592 if (I2C_SMBUS_READ == read_write) { 593 count = cp2112_write_read_req(buf, addr, 594 I2C_SMBUS_BLOCK_MAX, 595 command, NULL, 0); 596 } else { 597 count = cp2112_write_req(buf, addr, command, 598 data->block, 599 data->block[0] + 1); 600 } 601 break; 602 case I2C_SMBUS_BLOCK_PROC_CALL: 603 size = I2C_SMBUS_BLOCK_DATA; 604 read_write = I2C_SMBUS_READ; 605 606 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, 607 command, data->block, 608 data->block[0] + 1); 609 break; 610 default: 611 hid_warn(hdev, "Unsupported transaction %d\n", size); 612 return -EOPNOTSUPP; 613 } 614 615 if (count < 0) 616 return count; 617 618 ret = hid_hw_power(hdev, PM_HINT_FULLON); 619 if (ret < 0) { 620 hid_err(hdev, "power management error: %d\n", ret); 621 return ret; 622 } 623 624 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); 625 if (ret < 0) { 626 hid_warn(hdev, "Error starting transaction: %d\n", ret); 627 goto power_normal; 628 } 629 630 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { 631 ret = cp2112_xfer_status(dev); 632 if (-EBUSY == ret) 633 continue; 634 if (ret < 0) 635 goto power_normal; 636 break; 637 } 638 639 if (XFER_STATUS_RETRIES <= retries) { 640 hid_warn(hdev, "Transfer timed out, cancelling.\n"); 641 buf[0] = CP2112_CANCEL_TRANSFER; 642 buf[1] = 0x01; 643 644 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); 645 if (ret < 0) 646 hid_warn(hdev, "Error cancelling transaction: %d\n", 647 ret); 648 649 ret = -ETIMEDOUT; 650 goto power_normal; 651 } 652 653 if (I2C_SMBUS_WRITE == read_write) { 654 ret = 0; 655 goto power_normal; 656 } 657 658 if (I2C_SMBUS_BLOCK_DATA == size) 659 read_length = ret; 660 661 ret = cp2112_read(dev, buf, read_length); 662 if (ret < 0) 663 goto power_normal; 664 if (ret != read_length) { 665 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length); 666 ret = -EIO; 667 goto power_normal; 668 } 669 670 switch (size) { 671 case I2C_SMBUS_BYTE: 672 case I2C_SMBUS_BYTE_DATA: 673 data->byte = buf[0]; 674 break; 675 case I2C_SMBUS_WORD_DATA: 676 data->word = be16_to_cpup((__be16 *)buf); 677 break; 678 case I2C_SMBUS_BLOCK_DATA: 679 if (read_length > I2C_SMBUS_BLOCK_MAX) { 680 ret = -EPROTO; 681 goto power_normal; 682 } 683 684 memcpy(data->block, buf, read_length); 685 break; 686 } 687 688 ret = 0; 689 power_normal: 690 hid_hw_power(hdev, PM_HINT_NORMAL); 691 hid_dbg(hdev, "transfer finished: %d\n", ret); 692 return ret; 693 } 694 695 static u32 cp2112_functionality(struct i2c_adapter *adap) 696 { 697 return I2C_FUNC_I2C | 698 I2C_FUNC_SMBUS_BYTE | 699 I2C_FUNC_SMBUS_BYTE_DATA | 700 I2C_FUNC_SMBUS_WORD_DATA | 701 I2C_FUNC_SMBUS_BLOCK_DATA | 702 I2C_FUNC_SMBUS_I2C_BLOCK | 703 I2C_FUNC_SMBUS_PROC_CALL | 704 I2C_FUNC_SMBUS_BLOCK_PROC_CALL; 705 } 706 707 static const struct i2c_algorithm smbus_algorithm = { 708 .master_xfer = cp2112_i2c_xfer, 709 .smbus_xfer = cp2112_xfer, 710 .functionality = cp2112_functionality, 711 }; 712 713 static int cp2112_get_usb_config(struct hid_device *hdev, 714 struct cp2112_usb_config_report *cfg) 715 { 716 int ret; 717 718 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg), 719 HID_FEATURE_REPORT); 720 if (ret != sizeof(*cfg)) { 721 hid_err(hdev, "error reading usb config: %d\n", ret); 722 if (ret < 0) 723 return ret; 724 return -EIO; 725 } 726 727 return 0; 728 } 729 730 static int cp2112_set_usb_config(struct hid_device *hdev, 731 struct cp2112_usb_config_report *cfg) 732 { 733 int ret; 734 735 BUG_ON(cfg->report != CP2112_USB_CONFIG); 736 737 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg), 738 HID_FEATURE_REPORT); 739 if (ret != sizeof(*cfg)) { 740 hid_err(hdev, "error writing usb config: %d\n", ret); 741 if (ret < 0) 742 return ret; 743 return -EIO; 744 } 745 746 return 0; 747 } 748 749 static void chmod_sysfs_attrs(struct hid_device *hdev); 750 751 #define CP2112_CONFIG_ATTR(name, store, format, ...) \ 752 static ssize_t name##_store(struct device *kdev, \ 753 struct device_attribute *attr, const char *buf, \ 754 size_t count) \ 755 { \ 756 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \ 757 struct cp2112_usb_config_report cfg; \ 758 int ret = cp2112_get_usb_config(hdev, &cfg); \ 759 if (ret) \ 760 return ret; \ 761 store; \ 762 ret = cp2112_set_usb_config(hdev, &cfg); \ 763 if (ret) \ 764 return ret; \ 765 chmod_sysfs_attrs(hdev); \ 766 return count; \ 767 } \ 768 static ssize_t name##_show(struct device *kdev, \ 769 struct device_attribute *attr, char *buf) \ 770 { \ 771 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \ 772 struct cp2112_usb_config_report cfg; \ 773 int ret = cp2112_get_usb_config(hdev, &cfg); \ 774 if (ret) \ 775 return ret; \ 776 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \ 777 } \ 778 static DEVICE_ATTR_RW(name); 779 780 CP2112_CONFIG_ATTR(vendor_id, ({ 781 u16 vid; 782 783 if (sscanf(buf, "%hi", &vid) != 1) 784 return -EINVAL; 785 786 cfg.vid = cpu_to_le16(vid); 787 cfg.mask = 0x01; 788 }), "0x%04x\n", le16_to_cpu(cfg.vid)); 789 790 CP2112_CONFIG_ATTR(product_id, ({ 791 u16 pid; 792 793 if (sscanf(buf, "%hi", &pid) != 1) 794 return -EINVAL; 795 796 cfg.pid = cpu_to_le16(pid); 797 cfg.mask = 0x02; 798 }), "0x%04x\n", le16_to_cpu(cfg.pid)); 799 800 CP2112_CONFIG_ATTR(max_power, ({ 801 int mA; 802 803 if (sscanf(buf, "%i", &mA) != 1) 804 return -EINVAL; 805 806 cfg.max_power = (mA + 1) / 2; 807 cfg.mask = 0x04; 808 }), "%u mA\n", cfg.max_power * 2); 809 810 CP2112_CONFIG_ATTR(power_mode, ({ 811 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1) 812 return -EINVAL; 813 814 cfg.mask = 0x08; 815 }), "%u\n", cfg.power_mode); 816 817 CP2112_CONFIG_ATTR(release_version, ({ 818 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor) 819 != 2) 820 return -EINVAL; 821 822 cfg.mask = 0x10; 823 }), "%u.%u\n", cfg.release_major, cfg.release_minor); 824 825 #undef CP2112_CONFIG_ATTR 826 827 struct cp2112_pstring_attribute { 828 struct device_attribute attr; 829 unsigned char report; 830 }; 831 832 static ssize_t pstr_store(struct device *kdev, 833 struct device_attribute *kattr, const char *buf, 834 size_t count) 835 { 836 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); 837 struct cp2112_pstring_attribute *attr = 838 container_of(kattr, struct cp2112_pstring_attribute, attr); 839 struct cp2112_string_report report; 840 int ret; 841 842 memset(&report, 0, sizeof(report)); 843 844 ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN, 845 report.string, ARRAY_SIZE(report.string)); 846 report.report = attr->report; 847 report.length = ret * sizeof(report.string[0]) + 2; 848 report.type = USB_DT_STRING; 849 850 ret = cp2112_hid_output(hdev, &report.report, report.length + 1, 851 HID_FEATURE_REPORT); 852 if (ret != report.length + 1) { 853 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name, 854 ret); 855 if (ret < 0) 856 return ret; 857 return -EIO; 858 } 859 860 chmod_sysfs_attrs(hdev); 861 return count; 862 } 863 864 static ssize_t pstr_show(struct device *kdev, 865 struct device_attribute *kattr, char *buf) 866 { 867 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); 868 struct cp2112_pstring_attribute *attr = 869 container_of(kattr, struct cp2112_pstring_attribute, attr); 870 struct cp2112_string_report report; 871 u8 length; 872 int ret; 873 874 ret = cp2112_hid_get(hdev, attr->report, &report.report, 875 sizeof(report) - 1, HID_FEATURE_REPORT); 876 if (ret < 3) { 877 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name, 878 ret); 879 if (ret < 0) 880 return ret; 881 return -EIO; 882 } 883 884 if (report.length < 2) { 885 hid_err(hdev, "invalid %s string length: %d\n", 886 kattr->attr.name, report.length); 887 return -EIO; 888 } 889 890 length = report.length > ret - 1 ? ret - 1 : report.length; 891 length = (length - 2) / sizeof(report.string[0]); 892 ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf, 893 PAGE_SIZE - 1); 894 buf[ret++] = '\n'; 895 return ret; 896 } 897 898 #define CP2112_PSTR_ATTR(name, _report) \ 899 static struct cp2112_pstring_attribute dev_attr_##name = { \ 900 .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \ 901 .report = _report, \ 902 }; 903 904 CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING); 905 CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING); 906 CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING); 907 908 #undef CP2112_PSTR_ATTR 909 910 static const struct attribute_group cp2112_attr_group = { 911 .attrs = (struct attribute *[]){ 912 &dev_attr_vendor_id.attr, 913 &dev_attr_product_id.attr, 914 &dev_attr_max_power.attr, 915 &dev_attr_power_mode.attr, 916 &dev_attr_release_version.attr, 917 &dev_attr_manufacturer.attr.attr, 918 &dev_attr_product.attr.attr, 919 &dev_attr_serial.attr.attr, 920 NULL 921 } 922 }; 923 924 /* Chmoding our sysfs attributes is simply a way to expose which fields in the 925 * PROM have already been programmed. We do not depend on this preventing 926 * writing to these attributes since the CP2112 will simply ignore writes to 927 * already-programmed fields. This is why there is no sense in fixing this 928 * racy behaviour. 929 */ 930 static void chmod_sysfs_attrs(struct hid_device *hdev) 931 { 932 struct attribute **attr; 933 u8 buf[2]; 934 int ret; 935 936 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf), 937 HID_FEATURE_REPORT); 938 if (ret != sizeof(buf)) { 939 hid_err(hdev, "error reading lock byte: %d\n", ret); 940 return; 941 } 942 943 for (attr = cp2112_attr_group.attrs; *attr; ++attr) { 944 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO; 945 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode); 946 if (ret < 0) 947 hid_err(hdev, "error chmoding sysfs file %s\n", 948 (*attr)->name); 949 buf[1] >>= 1; 950 } 951 } 952 953 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) 954 { 955 struct cp2112_device *dev; 956 u8 buf[3]; 957 struct cp2112_smbus_config_report config; 958 int ret; 959 960 ret = hid_parse(hdev); 961 if (ret) { 962 hid_err(hdev, "parse failed\n"); 963 return ret; 964 } 965 966 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); 967 if (ret) { 968 hid_err(hdev, "hw start failed\n"); 969 return ret; 970 } 971 972 ret = hid_hw_open(hdev); 973 if (ret) { 974 hid_err(hdev, "hw open failed\n"); 975 goto err_hid_stop; 976 } 977 978 ret = hid_hw_power(hdev, PM_HINT_FULLON); 979 if (ret < 0) { 980 hid_err(hdev, "power management error: %d\n", ret); 981 goto err_hid_close; 982 } 983 984 ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf), 985 HID_FEATURE_REPORT); 986 if (ret != sizeof(buf)) { 987 hid_err(hdev, "error requesting version\n"); 988 if (ret >= 0) 989 ret = -EIO; 990 goto err_power_normal; 991 } 992 993 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n", 994 buf[1], buf[2]); 995 996 ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config, 997 sizeof(config), HID_FEATURE_REPORT); 998 if (ret != sizeof(config)) { 999 hid_err(hdev, "error requesting SMBus config\n"); 1000 if (ret >= 0) 1001 ret = -EIO; 1002 goto err_power_normal; 1003 } 1004 1005 config.retry_time = cpu_to_be16(1); 1006 1007 ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config), 1008 HID_FEATURE_REPORT); 1009 if (ret != sizeof(config)) { 1010 hid_err(hdev, "error setting SMBus config\n"); 1011 if (ret >= 0) 1012 ret = -EIO; 1013 goto err_power_normal; 1014 } 1015 1016 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1017 if (!dev) { 1018 ret = -ENOMEM; 1019 goto err_power_normal; 1020 } 1021 1022 hid_set_drvdata(hdev, (void *)dev); 1023 dev->hdev = hdev; 1024 dev->adap.owner = THIS_MODULE; 1025 dev->adap.class = I2C_CLASS_HWMON; 1026 dev->adap.algo = &smbus_algorithm; 1027 dev->adap.algo_data = dev; 1028 dev->adap.dev.parent = &hdev->dev; 1029 snprintf(dev->adap.name, sizeof(dev->adap.name), 1030 "CP2112 SMBus Bridge on hiddev%d", hdev->minor); 1031 init_waitqueue_head(&dev->wait); 1032 1033 hid_device_io_start(hdev); 1034 ret = i2c_add_adapter(&dev->adap); 1035 hid_device_io_stop(hdev); 1036 1037 if (ret) { 1038 hid_err(hdev, "error registering i2c adapter\n"); 1039 goto err_free_dev; 1040 } 1041 1042 hid_dbg(hdev, "adapter registered\n"); 1043 1044 dev->gc.label = "cp2112_gpio"; 1045 dev->gc.direction_input = cp2112_gpio_direction_input; 1046 dev->gc.direction_output = cp2112_gpio_direction_output; 1047 dev->gc.set = cp2112_gpio_set; 1048 dev->gc.get = cp2112_gpio_get; 1049 dev->gc.base = -1; 1050 dev->gc.ngpio = 8; 1051 dev->gc.can_sleep = 1; 1052 dev->gc.dev = &hdev->dev; 1053 1054 ret = gpiochip_add(&dev->gc); 1055 if (ret < 0) { 1056 hid_err(hdev, "error registering gpio chip\n"); 1057 goto err_free_i2c; 1058 } 1059 1060 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group); 1061 if (ret < 0) { 1062 hid_err(hdev, "error creating sysfs attrs\n"); 1063 goto err_gpiochip_remove; 1064 } 1065 1066 chmod_sysfs_attrs(hdev); 1067 hid_hw_power(hdev, PM_HINT_NORMAL); 1068 1069 return ret; 1070 1071 err_gpiochip_remove: 1072 gpiochip_remove(&dev->gc); 1073 err_free_i2c: 1074 i2c_del_adapter(&dev->adap); 1075 err_free_dev: 1076 kfree(dev); 1077 err_power_normal: 1078 hid_hw_power(hdev, PM_HINT_NORMAL); 1079 err_hid_close: 1080 hid_hw_close(hdev); 1081 err_hid_stop: 1082 hid_hw_stop(hdev); 1083 return ret; 1084 } 1085 1086 static void cp2112_remove(struct hid_device *hdev) 1087 { 1088 struct cp2112_device *dev = hid_get_drvdata(hdev); 1089 1090 sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); 1091 gpiochip_remove(&dev->gc); 1092 i2c_del_adapter(&dev->adap); 1093 /* i2c_del_adapter has finished removing all i2c devices from our 1094 * adapter. Well behaved devices should no longer call our cp2112_xfer 1095 * and should have waited for any pending calls to finish. It has also 1096 * waited for device_unregister(&adap->dev) to complete. Therefore we 1097 * can safely free our struct cp2112_device. 1098 */ 1099 hid_hw_close(hdev); 1100 hid_hw_stop(hdev); 1101 kfree(dev); 1102 } 1103 1104 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report, 1105 u8 *data, int size) 1106 { 1107 struct cp2112_device *dev = hid_get_drvdata(hdev); 1108 struct cp2112_xfer_status_report *xfer = (void *)data; 1109 1110 switch (data[0]) { 1111 case CP2112_TRANSFER_STATUS_RESPONSE: 1112 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n", 1113 xfer->status0, xfer->status1, 1114 be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length)); 1115 1116 switch (xfer->status0) { 1117 case STATUS0_IDLE: 1118 dev->xfer_status = -EAGAIN; 1119 break; 1120 case STATUS0_BUSY: 1121 dev->xfer_status = -EBUSY; 1122 break; 1123 case STATUS0_COMPLETE: 1124 dev->xfer_status = be16_to_cpu(xfer->length); 1125 break; 1126 case STATUS0_ERROR: 1127 switch (xfer->status1) { 1128 case STATUS1_TIMEOUT_NACK: 1129 case STATUS1_TIMEOUT_BUS: 1130 dev->xfer_status = -ETIMEDOUT; 1131 break; 1132 default: 1133 dev->xfer_status = -EIO; 1134 break; 1135 } 1136 break; 1137 default: 1138 dev->xfer_status = -EINVAL; 1139 break; 1140 } 1141 1142 atomic_set(&dev->xfer_avail, 1); 1143 break; 1144 case CP2112_DATA_READ_RESPONSE: 1145 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]); 1146 1147 dev->read_length = data[2]; 1148 if (dev->read_length > sizeof(dev->read_data)) 1149 dev->read_length = sizeof(dev->read_data); 1150 1151 memcpy(dev->read_data, &data[3], dev->read_length); 1152 atomic_set(&dev->read_avail, 1); 1153 break; 1154 default: 1155 hid_err(hdev, "unknown report\n"); 1156 1157 return 0; 1158 } 1159 1160 wake_up_interruptible(&dev->wait); 1161 return 1; 1162 } 1163 1164 static struct hid_driver cp2112_driver = { 1165 .name = "cp2112", 1166 .id_table = cp2112_devices, 1167 .probe = cp2112_probe, 1168 .remove = cp2112_remove, 1169 .raw_event = cp2112_raw_event, 1170 }; 1171 1172 module_hid_driver(cp2112_driver); 1173 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge"); 1174 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>"); 1175 MODULE_LICENSE("GPL"); 1176 1177