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 u8 hwversion; 160 int xfer_status; 161 atomic_t read_avail; 162 atomic_t xfer_avail; 163 struct gpio_chip gc; 164 }; 165 166 static int gpio_push_pull = 0xFF; 167 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR); 168 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask"); 169 170 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 171 { 172 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 173 gc); 174 struct hid_device *hdev = dev->hdev; 175 u8 buf[5]; 176 int ret; 177 178 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, 179 sizeof(buf), HID_FEATURE_REPORT, 180 HID_REQ_GET_REPORT); 181 if (ret != sizeof(buf)) { 182 hid_err(hdev, "error requesting GPIO config: %d\n", ret); 183 return ret; 184 } 185 186 buf[1] &= ~(1 << offset); 187 buf[2] = gpio_push_pull; 188 189 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), 190 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 191 if (ret < 0) { 192 hid_err(hdev, "error setting GPIO config: %d\n", ret); 193 return ret; 194 } 195 196 return 0; 197 } 198 199 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 200 { 201 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 202 gc); 203 struct hid_device *hdev = dev->hdev; 204 u8 buf[3]; 205 int ret; 206 207 buf[0] = CP2112_GPIO_SET; 208 buf[1] = value ? 0xff : 0; 209 buf[2] = 1 << offset; 210 211 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf), 212 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 213 if (ret < 0) 214 hid_err(hdev, "error setting GPIO values: %d\n", ret); 215 } 216 217 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset) 218 { 219 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 220 gc); 221 struct hid_device *hdev = dev->hdev; 222 u8 buf[2]; 223 int ret; 224 225 ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf), 226 HID_FEATURE_REPORT, HID_REQ_GET_REPORT); 227 if (ret != sizeof(buf)) { 228 hid_err(hdev, "error requesting GPIO values: %d\n", ret); 229 return ret; 230 } 231 232 return (buf[1] >> offset) & 1; 233 } 234 235 static int cp2112_gpio_direction_output(struct gpio_chip *chip, 236 unsigned offset, int value) 237 { 238 struct cp2112_device *dev = container_of(chip, struct cp2112_device, 239 gc); 240 struct hid_device *hdev = dev->hdev; 241 u8 buf[5]; 242 int ret; 243 244 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, 245 sizeof(buf), HID_FEATURE_REPORT, 246 HID_REQ_GET_REPORT); 247 if (ret != sizeof(buf)) { 248 hid_err(hdev, "error requesting GPIO config: %d\n", ret); 249 return ret; 250 } 251 252 buf[1] |= 1 << offset; 253 buf[2] = gpio_push_pull; 254 255 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), 256 HID_FEATURE_REPORT, HID_REQ_SET_REPORT); 257 if (ret < 0) { 258 hid_err(hdev, "error setting GPIO config: %d\n", ret); 259 return ret; 260 } 261 262 /* 263 * Set gpio value when output direction is already set, 264 * as specified in AN495, Rev. 0.2, cpt. 4.4 265 */ 266 cp2112_gpio_set(chip, offset, value); 267 268 return 0; 269 } 270 271 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number, 272 u8 *data, size_t count, unsigned char report_type) 273 { 274 u8 *buf; 275 int ret; 276 277 buf = kmalloc(count, GFP_KERNEL); 278 if (!buf) 279 return -ENOMEM; 280 281 ret = hid_hw_raw_request(hdev, report_number, buf, count, 282 report_type, HID_REQ_GET_REPORT); 283 memcpy(data, buf, count); 284 kfree(buf); 285 return ret; 286 } 287 288 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count, 289 unsigned char report_type) 290 { 291 u8 *buf; 292 int ret; 293 294 buf = kmemdup(data, count, GFP_KERNEL); 295 if (!buf) 296 return -ENOMEM; 297 298 if (report_type == HID_OUTPUT_REPORT) 299 ret = hid_hw_output_report(hdev, buf, count); 300 else 301 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type, 302 HID_REQ_SET_REPORT); 303 304 kfree(buf); 305 return ret; 306 } 307 308 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail) 309 { 310 int ret = 0; 311 312 /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a 313 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to 314 * come in cp2112_raw_event or timeout. There will only be one of these 315 * in flight at any one time. The timeout is extremely large and is a 316 * last resort if the CP2112 has died. If we do timeout we don't expect 317 * to receive the response which would cause data races, it's not like 318 * we can do anything about it anyway. 319 */ 320 ret = wait_event_interruptible_timeout(dev->wait, 321 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT)); 322 if (-ERESTARTSYS == ret) 323 return ret; 324 if (!ret) 325 return -ETIMEDOUT; 326 327 atomic_set(avail, 0); 328 return 0; 329 } 330 331 static int cp2112_xfer_status(struct cp2112_device *dev) 332 { 333 struct hid_device *hdev = dev->hdev; 334 u8 buf[2]; 335 int ret; 336 337 buf[0] = CP2112_TRANSFER_STATUS_REQUEST; 338 buf[1] = 0x01; 339 atomic_set(&dev->xfer_avail, 0); 340 341 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); 342 if (ret < 0) { 343 hid_warn(hdev, "Error requesting status: %d\n", ret); 344 return ret; 345 } 346 347 ret = cp2112_wait(dev, &dev->xfer_avail); 348 if (ret) 349 return ret; 350 351 return dev->xfer_status; 352 } 353 354 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size) 355 { 356 struct hid_device *hdev = dev->hdev; 357 struct cp2112_force_read_report report; 358 int ret; 359 360 if (size > sizeof(dev->read_data)) 361 size = sizeof(dev->read_data); 362 report.report = CP2112_DATA_READ_FORCE_SEND; 363 report.length = cpu_to_be16(size); 364 365 atomic_set(&dev->read_avail, 0); 366 367 ret = cp2112_hid_output(hdev, &report.report, sizeof(report), 368 HID_OUTPUT_REPORT); 369 if (ret < 0) { 370 hid_warn(hdev, "Error requesting data: %d\n", ret); 371 return ret; 372 } 373 374 ret = cp2112_wait(dev, &dev->read_avail); 375 if (ret) 376 return ret; 377 378 hid_dbg(hdev, "read %d of %zd bytes requested\n", 379 dev->read_length, size); 380 381 if (size > dev->read_length) 382 size = dev->read_length; 383 384 memcpy(data, dev->read_data, size); 385 return dev->read_length; 386 } 387 388 static int cp2112_read_req(void *buf, u8 slave_address, u16 length) 389 { 390 struct cp2112_read_req_report *report = buf; 391 392 if (length < 1 || length > 512) 393 return -EINVAL; 394 395 report->report = CP2112_DATA_READ_REQUEST; 396 report->slave_address = slave_address << 1; 397 report->length = cpu_to_be16(length); 398 return sizeof(*report); 399 } 400 401 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length, 402 u8 command, u8 *data, u8 data_length) 403 { 404 struct cp2112_write_read_req_report *report = buf; 405 406 if (length < 1 || length > 512 407 || data_length > sizeof(report->target_address) - 1) 408 return -EINVAL; 409 410 report->report = CP2112_DATA_WRITE_READ_REQUEST; 411 report->slave_address = slave_address << 1; 412 report->length = cpu_to_be16(length); 413 report->target_address_length = data_length + 1; 414 report->target_address[0] = command; 415 memcpy(&report->target_address[1], data, data_length); 416 return data_length + 6; 417 } 418 419 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data, 420 u8 data_length) 421 { 422 struct cp2112_write_req_report *report = buf; 423 424 if (data_length > sizeof(report->data) - 1) 425 return -EINVAL; 426 427 report->report = CP2112_DATA_WRITE_REQUEST; 428 report->slave_address = slave_address << 1; 429 report->length = data_length + 1; 430 report->data[0] = command; 431 memcpy(&report->data[1], data, data_length); 432 return data_length + 4; 433 } 434 435 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data, 436 u8 data_length) 437 { 438 struct cp2112_write_req_report *report = buf; 439 440 if (data_length > sizeof(report->data)) 441 return -EINVAL; 442 443 report->report = CP2112_DATA_WRITE_REQUEST; 444 report->slave_address = slave_address << 1; 445 report->length = data_length; 446 memcpy(report->data, data, data_length); 447 return data_length + 3; 448 } 449 450 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address, 451 u8 *addr, int addr_length, 452 int read_length) 453 { 454 struct cp2112_write_read_req_report *report = buf; 455 456 if (read_length < 1 || read_length > 512 || 457 addr_length > sizeof(report->target_address)) 458 return -EINVAL; 459 460 report->report = CP2112_DATA_WRITE_READ_REQUEST; 461 report->slave_address = slave_address << 1; 462 report->length = cpu_to_be16(read_length); 463 report->target_address_length = addr_length; 464 memcpy(report->target_address, addr, addr_length); 465 return addr_length + 5; 466 } 467 468 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 469 int num) 470 { 471 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; 472 struct hid_device *hdev = dev->hdev; 473 u8 buf[64]; 474 ssize_t count; 475 ssize_t read_length = 0; 476 u8 *read_buf = NULL; 477 unsigned int retries; 478 int ret; 479 480 hid_dbg(hdev, "I2C %d messages\n", num); 481 482 if (num == 1) { 483 if (msgs->flags & I2C_M_RD) { 484 hid_dbg(hdev, "I2C read %#04x len %d\n", 485 msgs->addr, msgs->len); 486 read_length = msgs->len; 487 read_buf = msgs->buf; 488 count = cp2112_read_req(buf, msgs->addr, msgs->len); 489 } else { 490 hid_dbg(hdev, "I2C write %#04x len %d\n", 491 msgs->addr, msgs->len); 492 count = cp2112_i2c_write_req(buf, msgs->addr, 493 msgs->buf, msgs->len); 494 } 495 if (count < 0) 496 return count; 497 } else if (dev->hwversion > 1 && /* no repeated start in rev 1 */ 498 num == 2 && 499 msgs[0].addr == msgs[1].addr && 500 !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) { 501 hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n", 502 msgs[0].addr, msgs[0].len, msgs[1].len); 503 read_length = msgs[1].len; 504 read_buf = msgs[1].buf; 505 count = cp2112_i2c_write_read_req(buf, msgs[0].addr, 506 msgs[0].buf, msgs[0].len, msgs[1].len); 507 if (count < 0) 508 return count; 509 } else { 510 hid_err(hdev, 511 "Multi-message I2C transactions not supported\n"); 512 return -EOPNOTSUPP; 513 } 514 515 ret = hid_hw_power(hdev, PM_HINT_FULLON); 516 if (ret < 0) { 517 hid_err(hdev, "power management error: %d\n", ret); 518 return ret; 519 } 520 521 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); 522 if (ret < 0) { 523 hid_warn(hdev, "Error starting transaction: %d\n", ret); 524 goto power_normal; 525 } 526 527 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { 528 ret = cp2112_xfer_status(dev); 529 if (-EBUSY == ret) 530 continue; 531 if (ret < 0) 532 goto power_normal; 533 break; 534 } 535 536 if (XFER_STATUS_RETRIES <= retries) { 537 hid_warn(hdev, "Transfer timed out, cancelling.\n"); 538 buf[0] = CP2112_CANCEL_TRANSFER; 539 buf[1] = 0x01; 540 541 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); 542 if (ret < 0) 543 hid_warn(hdev, "Error cancelling transaction: %d\n", 544 ret); 545 546 ret = -ETIMEDOUT; 547 goto power_normal; 548 } 549 550 for (count = 0; count < read_length;) { 551 ret = cp2112_read(dev, read_buf + count, read_length - count); 552 if (ret < 0) 553 goto power_normal; 554 if (ret == 0) { 555 hid_err(hdev, "read returned 0\n"); 556 ret = -EIO; 557 goto power_normal; 558 } 559 count += ret; 560 if (count > read_length) { 561 /* 562 * The hardware returned too much data. 563 * This is mostly harmless because cp2112_read() 564 * has a limit check so didn't overrun our 565 * buffer. Nevertheless, we return an error 566 * because something is seriously wrong and 567 * it shouldn't go unnoticed. 568 */ 569 hid_err(hdev, "long read: %d > %zd\n", 570 ret, read_length - count + ret); 571 ret = -EIO; 572 goto power_normal; 573 } 574 } 575 576 /* return the number of transferred messages */ 577 ret = num; 578 579 power_normal: 580 hid_hw_power(hdev, PM_HINT_NORMAL); 581 hid_dbg(hdev, "I2C transfer finished: %d\n", ret); 582 return ret; 583 } 584 585 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, 586 unsigned short flags, char read_write, u8 command, 587 int size, union i2c_smbus_data *data) 588 { 589 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; 590 struct hid_device *hdev = dev->hdev; 591 u8 buf[64]; 592 __le16 word; 593 ssize_t count; 594 size_t read_length = 0; 595 unsigned int retries; 596 int ret; 597 598 hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n", 599 read_write == I2C_SMBUS_WRITE ? "write" : "read", 600 addr, flags, command, size); 601 602 switch (size) { 603 case I2C_SMBUS_BYTE: 604 read_length = 1; 605 606 if (I2C_SMBUS_READ == read_write) 607 count = cp2112_read_req(buf, addr, read_length); 608 else 609 count = cp2112_write_req(buf, addr, command, NULL, 610 0); 611 break; 612 case I2C_SMBUS_BYTE_DATA: 613 read_length = 1; 614 615 if (I2C_SMBUS_READ == read_write) 616 count = cp2112_write_read_req(buf, addr, read_length, 617 command, NULL, 0); 618 else 619 count = cp2112_write_req(buf, addr, command, 620 &data->byte, 1); 621 break; 622 case I2C_SMBUS_WORD_DATA: 623 read_length = 2; 624 word = cpu_to_le16(data->word); 625 626 if (I2C_SMBUS_READ == read_write) 627 count = cp2112_write_read_req(buf, addr, read_length, 628 command, NULL, 0); 629 else 630 count = cp2112_write_req(buf, addr, command, 631 (u8 *)&word, 2); 632 break; 633 case I2C_SMBUS_PROC_CALL: 634 size = I2C_SMBUS_WORD_DATA; 635 read_write = I2C_SMBUS_READ; 636 read_length = 2; 637 word = cpu_to_le16(data->word); 638 639 count = cp2112_write_read_req(buf, addr, read_length, command, 640 (u8 *)&word, 2); 641 break; 642 case I2C_SMBUS_I2C_BLOCK_DATA: 643 size = I2C_SMBUS_BLOCK_DATA; 644 /* fallthrough */ 645 case I2C_SMBUS_BLOCK_DATA: 646 if (I2C_SMBUS_READ == read_write) { 647 count = cp2112_write_read_req(buf, addr, 648 I2C_SMBUS_BLOCK_MAX, 649 command, NULL, 0); 650 } else { 651 count = cp2112_write_req(buf, addr, command, 652 data->block, 653 data->block[0] + 1); 654 } 655 break; 656 case I2C_SMBUS_BLOCK_PROC_CALL: 657 size = I2C_SMBUS_BLOCK_DATA; 658 read_write = I2C_SMBUS_READ; 659 660 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, 661 command, data->block, 662 data->block[0] + 1); 663 break; 664 default: 665 hid_warn(hdev, "Unsupported transaction %d\n", size); 666 return -EOPNOTSUPP; 667 } 668 669 if (count < 0) 670 return count; 671 672 ret = hid_hw_power(hdev, PM_HINT_FULLON); 673 if (ret < 0) { 674 hid_err(hdev, "power management error: %d\n", ret); 675 return ret; 676 } 677 678 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); 679 if (ret < 0) { 680 hid_warn(hdev, "Error starting transaction: %d\n", ret); 681 goto power_normal; 682 } 683 684 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { 685 ret = cp2112_xfer_status(dev); 686 if (-EBUSY == ret) 687 continue; 688 if (ret < 0) 689 goto power_normal; 690 break; 691 } 692 693 if (XFER_STATUS_RETRIES <= retries) { 694 hid_warn(hdev, "Transfer timed out, cancelling.\n"); 695 buf[0] = CP2112_CANCEL_TRANSFER; 696 buf[1] = 0x01; 697 698 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); 699 if (ret < 0) 700 hid_warn(hdev, "Error cancelling transaction: %d\n", 701 ret); 702 703 ret = -ETIMEDOUT; 704 goto power_normal; 705 } 706 707 if (I2C_SMBUS_WRITE == read_write) { 708 ret = 0; 709 goto power_normal; 710 } 711 712 if (I2C_SMBUS_BLOCK_DATA == size) 713 read_length = ret; 714 715 ret = cp2112_read(dev, buf, read_length); 716 if (ret < 0) 717 goto power_normal; 718 if (ret != read_length) { 719 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length); 720 ret = -EIO; 721 goto power_normal; 722 } 723 724 switch (size) { 725 case I2C_SMBUS_BYTE: 726 case I2C_SMBUS_BYTE_DATA: 727 data->byte = buf[0]; 728 break; 729 case I2C_SMBUS_WORD_DATA: 730 data->word = le16_to_cpup((__le16 *)buf); 731 break; 732 case I2C_SMBUS_BLOCK_DATA: 733 if (read_length > I2C_SMBUS_BLOCK_MAX) { 734 ret = -EPROTO; 735 goto power_normal; 736 } 737 738 memcpy(data->block, buf, read_length); 739 break; 740 } 741 742 ret = 0; 743 power_normal: 744 hid_hw_power(hdev, PM_HINT_NORMAL); 745 hid_dbg(hdev, "transfer finished: %d\n", ret); 746 return ret; 747 } 748 749 static u32 cp2112_functionality(struct i2c_adapter *adap) 750 { 751 return I2C_FUNC_I2C | 752 I2C_FUNC_SMBUS_BYTE | 753 I2C_FUNC_SMBUS_BYTE_DATA | 754 I2C_FUNC_SMBUS_WORD_DATA | 755 I2C_FUNC_SMBUS_BLOCK_DATA | 756 I2C_FUNC_SMBUS_I2C_BLOCK | 757 I2C_FUNC_SMBUS_PROC_CALL | 758 I2C_FUNC_SMBUS_BLOCK_PROC_CALL; 759 } 760 761 static const struct i2c_algorithm smbus_algorithm = { 762 .master_xfer = cp2112_i2c_xfer, 763 .smbus_xfer = cp2112_xfer, 764 .functionality = cp2112_functionality, 765 }; 766 767 static int cp2112_get_usb_config(struct hid_device *hdev, 768 struct cp2112_usb_config_report *cfg) 769 { 770 int ret; 771 772 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg), 773 HID_FEATURE_REPORT); 774 if (ret != sizeof(*cfg)) { 775 hid_err(hdev, "error reading usb config: %d\n", ret); 776 if (ret < 0) 777 return ret; 778 return -EIO; 779 } 780 781 return 0; 782 } 783 784 static int cp2112_set_usb_config(struct hid_device *hdev, 785 struct cp2112_usb_config_report *cfg) 786 { 787 int ret; 788 789 BUG_ON(cfg->report != CP2112_USB_CONFIG); 790 791 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg), 792 HID_FEATURE_REPORT); 793 if (ret != sizeof(*cfg)) { 794 hid_err(hdev, "error writing usb config: %d\n", ret); 795 if (ret < 0) 796 return ret; 797 return -EIO; 798 } 799 800 return 0; 801 } 802 803 static void chmod_sysfs_attrs(struct hid_device *hdev); 804 805 #define CP2112_CONFIG_ATTR(name, store, format, ...) \ 806 static ssize_t name##_store(struct device *kdev, \ 807 struct device_attribute *attr, const char *buf, \ 808 size_t count) \ 809 { \ 810 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \ 811 struct cp2112_usb_config_report cfg; \ 812 int ret = cp2112_get_usb_config(hdev, &cfg); \ 813 if (ret) \ 814 return ret; \ 815 store; \ 816 ret = cp2112_set_usb_config(hdev, &cfg); \ 817 if (ret) \ 818 return ret; \ 819 chmod_sysfs_attrs(hdev); \ 820 return count; \ 821 } \ 822 static ssize_t name##_show(struct device *kdev, \ 823 struct device_attribute *attr, char *buf) \ 824 { \ 825 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \ 826 struct cp2112_usb_config_report cfg; \ 827 int ret = cp2112_get_usb_config(hdev, &cfg); \ 828 if (ret) \ 829 return ret; \ 830 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \ 831 } \ 832 static DEVICE_ATTR_RW(name); 833 834 CP2112_CONFIG_ATTR(vendor_id, ({ 835 u16 vid; 836 837 if (sscanf(buf, "%hi", &vid) != 1) 838 return -EINVAL; 839 840 cfg.vid = cpu_to_le16(vid); 841 cfg.mask = 0x01; 842 }), "0x%04x\n", le16_to_cpu(cfg.vid)); 843 844 CP2112_CONFIG_ATTR(product_id, ({ 845 u16 pid; 846 847 if (sscanf(buf, "%hi", &pid) != 1) 848 return -EINVAL; 849 850 cfg.pid = cpu_to_le16(pid); 851 cfg.mask = 0x02; 852 }), "0x%04x\n", le16_to_cpu(cfg.pid)); 853 854 CP2112_CONFIG_ATTR(max_power, ({ 855 int mA; 856 857 if (sscanf(buf, "%i", &mA) != 1) 858 return -EINVAL; 859 860 cfg.max_power = (mA + 1) / 2; 861 cfg.mask = 0x04; 862 }), "%u mA\n", cfg.max_power * 2); 863 864 CP2112_CONFIG_ATTR(power_mode, ({ 865 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1) 866 return -EINVAL; 867 868 cfg.mask = 0x08; 869 }), "%u\n", cfg.power_mode); 870 871 CP2112_CONFIG_ATTR(release_version, ({ 872 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor) 873 != 2) 874 return -EINVAL; 875 876 cfg.mask = 0x10; 877 }), "%u.%u\n", cfg.release_major, cfg.release_minor); 878 879 #undef CP2112_CONFIG_ATTR 880 881 struct cp2112_pstring_attribute { 882 struct device_attribute attr; 883 unsigned char report; 884 }; 885 886 static ssize_t pstr_store(struct device *kdev, 887 struct device_attribute *kattr, const char *buf, 888 size_t count) 889 { 890 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); 891 struct cp2112_pstring_attribute *attr = 892 container_of(kattr, struct cp2112_pstring_attribute, attr); 893 struct cp2112_string_report report; 894 int ret; 895 896 memset(&report, 0, sizeof(report)); 897 898 ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN, 899 report.string, ARRAY_SIZE(report.string)); 900 report.report = attr->report; 901 report.length = ret * sizeof(report.string[0]) + 2; 902 report.type = USB_DT_STRING; 903 904 ret = cp2112_hid_output(hdev, &report.report, report.length + 1, 905 HID_FEATURE_REPORT); 906 if (ret != report.length + 1) { 907 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name, 908 ret); 909 if (ret < 0) 910 return ret; 911 return -EIO; 912 } 913 914 chmod_sysfs_attrs(hdev); 915 return count; 916 } 917 918 static ssize_t pstr_show(struct device *kdev, 919 struct device_attribute *kattr, char *buf) 920 { 921 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); 922 struct cp2112_pstring_attribute *attr = 923 container_of(kattr, struct cp2112_pstring_attribute, attr); 924 struct cp2112_string_report report; 925 u8 length; 926 int ret; 927 928 ret = cp2112_hid_get(hdev, attr->report, &report.report, 929 sizeof(report) - 1, HID_FEATURE_REPORT); 930 if (ret < 3) { 931 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name, 932 ret); 933 if (ret < 0) 934 return ret; 935 return -EIO; 936 } 937 938 if (report.length < 2) { 939 hid_err(hdev, "invalid %s string length: %d\n", 940 kattr->attr.name, report.length); 941 return -EIO; 942 } 943 944 length = report.length > ret - 1 ? ret - 1 : report.length; 945 length = (length - 2) / sizeof(report.string[0]); 946 ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf, 947 PAGE_SIZE - 1); 948 buf[ret++] = '\n'; 949 return ret; 950 } 951 952 #define CP2112_PSTR_ATTR(name, _report) \ 953 static struct cp2112_pstring_attribute dev_attr_##name = { \ 954 .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \ 955 .report = _report, \ 956 }; 957 958 CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING); 959 CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING); 960 CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING); 961 962 #undef CP2112_PSTR_ATTR 963 964 static const struct attribute_group cp2112_attr_group = { 965 .attrs = (struct attribute *[]){ 966 &dev_attr_vendor_id.attr, 967 &dev_attr_product_id.attr, 968 &dev_attr_max_power.attr, 969 &dev_attr_power_mode.attr, 970 &dev_attr_release_version.attr, 971 &dev_attr_manufacturer.attr.attr, 972 &dev_attr_product.attr.attr, 973 &dev_attr_serial.attr.attr, 974 NULL 975 } 976 }; 977 978 /* Chmoding our sysfs attributes is simply a way to expose which fields in the 979 * PROM have already been programmed. We do not depend on this preventing 980 * writing to these attributes since the CP2112 will simply ignore writes to 981 * already-programmed fields. This is why there is no sense in fixing this 982 * racy behaviour. 983 */ 984 static void chmod_sysfs_attrs(struct hid_device *hdev) 985 { 986 struct attribute **attr; 987 u8 buf[2]; 988 int ret; 989 990 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf), 991 HID_FEATURE_REPORT); 992 if (ret != sizeof(buf)) { 993 hid_err(hdev, "error reading lock byte: %d\n", ret); 994 return; 995 } 996 997 for (attr = cp2112_attr_group.attrs; *attr; ++attr) { 998 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO; 999 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode); 1000 if (ret < 0) 1001 hid_err(hdev, "error chmoding sysfs file %s\n", 1002 (*attr)->name); 1003 buf[1] >>= 1; 1004 } 1005 } 1006 1007 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) 1008 { 1009 struct cp2112_device *dev; 1010 u8 buf[3]; 1011 struct cp2112_smbus_config_report config; 1012 int ret; 1013 1014 ret = hid_parse(hdev); 1015 if (ret) { 1016 hid_err(hdev, "parse failed\n"); 1017 return ret; 1018 } 1019 1020 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); 1021 if (ret) { 1022 hid_err(hdev, "hw start failed\n"); 1023 return ret; 1024 } 1025 1026 ret = hid_hw_open(hdev); 1027 if (ret) { 1028 hid_err(hdev, "hw open failed\n"); 1029 goto err_hid_stop; 1030 } 1031 1032 ret = hid_hw_power(hdev, PM_HINT_FULLON); 1033 if (ret < 0) { 1034 hid_err(hdev, "power management error: %d\n", ret); 1035 goto err_hid_close; 1036 } 1037 1038 ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf), 1039 HID_FEATURE_REPORT); 1040 if (ret != sizeof(buf)) { 1041 hid_err(hdev, "error requesting version\n"); 1042 if (ret >= 0) 1043 ret = -EIO; 1044 goto err_power_normal; 1045 } 1046 1047 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n", 1048 buf[1], buf[2]); 1049 1050 ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config, 1051 sizeof(config), HID_FEATURE_REPORT); 1052 if (ret != sizeof(config)) { 1053 hid_err(hdev, "error requesting SMBus config\n"); 1054 if (ret >= 0) 1055 ret = -EIO; 1056 goto err_power_normal; 1057 } 1058 1059 config.retry_time = cpu_to_be16(1); 1060 1061 ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config), 1062 HID_FEATURE_REPORT); 1063 if (ret != sizeof(config)) { 1064 hid_err(hdev, "error setting SMBus config\n"); 1065 if (ret >= 0) 1066 ret = -EIO; 1067 goto err_power_normal; 1068 } 1069 1070 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1071 if (!dev) { 1072 ret = -ENOMEM; 1073 goto err_power_normal; 1074 } 1075 1076 hid_set_drvdata(hdev, (void *)dev); 1077 dev->hdev = hdev; 1078 dev->adap.owner = THIS_MODULE; 1079 dev->adap.class = I2C_CLASS_HWMON; 1080 dev->adap.algo = &smbus_algorithm; 1081 dev->adap.algo_data = dev; 1082 dev->adap.dev.parent = &hdev->dev; 1083 snprintf(dev->adap.name, sizeof(dev->adap.name), 1084 "CP2112 SMBus Bridge on hiddev%d", hdev->minor); 1085 dev->hwversion = buf[2]; 1086 init_waitqueue_head(&dev->wait); 1087 1088 hid_device_io_start(hdev); 1089 ret = i2c_add_adapter(&dev->adap); 1090 hid_device_io_stop(hdev); 1091 1092 if (ret) { 1093 hid_err(hdev, "error registering i2c adapter\n"); 1094 goto err_free_dev; 1095 } 1096 1097 hid_dbg(hdev, "adapter registered\n"); 1098 1099 dev->gc.label = "cp2112_gpio"; 1100 dev->gc.direction_input = cp2112_gpio_direction_input; 1101 dev->gc.direction_output = cp2112_gpio_direction_output; 1102 dev->gc.set = cp2112_gpio_set; 1103 dev->gc.get = cp2112_gpio_get; 1104 dev->gc.base = -1; 1105 dev->gc.ngpio = 8; 1106 dev->gc.can_sleep = 1; 1107 dev->gc.dev = &hdev->dev; 1108 1109 ret = gpiochip_add(&dev->gc); 1110 if (ret < 0) { 1111 hid_err(hdev, "error registering gpio chip\n"); 1112 goto err_free_i2c; 1113 } 1114 1115 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group); 1116 if (ret < 0) { 1117 hid_err(hdev, "error creating sysfs attrs\n"); 1118 goto err_gpiochip_remove; 1119 } 1120 1121 chmod_sysfs_attrs(hdev); 1122 hid_hw_power(hdev, PM_HINT_NORMAL); 1123 1124 return ret; 1125 1126 err_gpiochip_remove: 1127 gpiochip_remove(&dev->gc); 1128 err_free_i2c: 1129 i2c_del_adapter(&dev->adap); 1130 err_free_dev: 1131 kfree(dev); 1132 err_power_normal: 1133 hid_hw_power(hdev, PM_HINT_NORMAL); 1134 err_hid_close: 1135 hid_hw_close(hdev); 1136 err_hid_stop: 1137 hid_hw_stop(hdev); 1138 return ret; 1139 } 1140 1141 static void cp2112_remove(struct hid_device *hdev) 1142 { 1143 struct cp2112_device *dev = hid_get_drvdata(hdev); 1144 1145 sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); 1146 gpiochip_remove(&dev->gc); 1147 i2c_del_adapter(&dev->adap); 1148 /* i2c_del_adapter has finished removing all i2c devices from our 1149 * adapter. Well behaved devices should no longer call our cp2112_xfer 1150 * and should have waited for any pending calls to finish. It has also 1151 * waited for device_unregister(&adap->dev) to complete. Therefore we 1152 * can safely free our struct cp2112_device. 1153 */ 1154 hid_hw_close(hdev); 1155 hid_hw_stop(hdev); 1156 kfree(dev); 1157 } 1158 1159 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report, 1160 u8 *data, int size) 1161 { 1162 struct cp2112_device *dev = hid_get_drvdata(hdev); 1163 struct cp2112_xfer_status_report *xfer = (void *)data; 1164 1165 switch (data[0]) { 1166 case CP2112_TRANSFER_STATUS_RESPONSE: 1167 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n", 1168 xfer->status0, xfer->status1, 1169 be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length)); 1170 1171 switch (xfer->status0) { 1172 case STATUS0_IDLE: 1173 dev->xfer_status = -EAGAIN; 1174 break; 1175 case STATUS0_BUSY: 1176 dev->xfer_status = -EBUSY; 1177 break; 1178 case STATUS0_COMPLETE: 1179 dev->xfer_status = be16_to_cpu(xfer->length); 1180 break; 1181 case STATUS0_ERROR: 1182 switch (xfer->status1) { 1183 case STATUS1_TIMEOUT_NACK: 1184 case STATUS1_TIMEOUT_BUS: 1185 dev->xfer_status = -ETIMEDOUT; 1186 break; 1187 default: 1188 dev->xfer_status = -EIO; 1189 break; 1190 } 1191 break; 1192 default: 1193 dev->xfer_status = -EINVAL; 1194 break; 1195 } 1196 1197 atomic_set(&dev->xfer_avail, 1); 1198 break; 1199 case CP2112_DATA_READ_RESPONSE: 1200 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]); 1201 1202 dev->read_length = data[2]; 1203 if (dev->read_length > sizeof(dev->read_data)) 1204 dev->read_length = sizeof(dev->read_data); 1205 1206 memcpy(dev->read_data, &data[3], dev->read_length); 1207 atomic_set(&dev->read_avail, 1); 1208 break; 1209 default: 1210 hid_err(hdev, "unknown report\n"); 1211 1212 return 0; 1213 } 1214 1215 wake_up_interruptible(&dev->wait); 1216 return 1; 1217 } 1218 1219 static struct hid_driver cp2112_driver = { 1220 .name = "cp2112", 1221 .id_table = cp2112_devices, 1222 .probe = cp2112_probe, 1223 .remove = cp2112_remove, 1224 .raw_event = cp2112_raw_event, 1225 }; 1226 1227 module_hid_driver(cp2112_driver); 1228 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge"); 1229 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>"); 1230 MODULE_LICENSE("GPL"); 1231 1232