1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * MCP2221A - Microchip USB to I2C Host Protocol Bridge 4 * 5 * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com> 6 * 7 * Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf 8 */ 9 10 #include <linux/module.h> 11 #include <linux/err.h> 12 #include <linux/mutex.h> 13 #include <linux/completion.h> 14 #include <linux/delay.h> 15 #include <linux/hid.h> 16 #include <linux/hidraw.h> 17 #include <linux/i2c.h> 18 #include <linux/gpio/driver.h> 19 #include "hid-ids.h" 20 21 /* Commands codes in a raw output report */ 22 enum { 23 MCP2221_I2C_WR_DATA = 0x90, 24 MCP2221_I2C_WR_NO_STOP = 0x94, 25 MCP2221_I2C_RD_DATA = 0x91, 26 MCP2221_I2C_RD_RPT_START = 0x93, 27 MCP2221_I2C_GET_DATA = 0x40, 28 MCP2221_I2C_PARAM_OR_STATUS = 0x10, 29 MCP2221_I2C_SET_SPEED = 0x20, 30 MCP2221_I2C_CANCEL = 0x10, 31 MCP2221_GPIO_SET = 0x50, 32 MCP2221_GPIO_GET = 0x51, 33 }; 34 35 /* Response codes in a raw input report */ 36 enum { 37 MCP2221_SUCCESS = 0x00, 38 MCP2221_I2C_ENG_BUSY = 0x01, 39 MCP2221_I2C_START_TOUT = 0x12, 40 MCP2221_I2C_STOP_TOUT = 0x62, 41 MCP2221_I2C_WRADDRL_TOUT = 0x23, 42 MCP2221_I2C_WRDATA_TOUT = 0x44, 43 MCP2221_I2C_WRADDRL_NACK = 0x25, 44 MCP2221_I2C_MASK_ADDR_NACK = 0x40, 45 MCP2221_I2C_WRADDRL_SEND = 0x21, 46 MCP2221_I2C_ADDR_NACK = 0x25, 47 MCP2221_I2C_READ_COMPL = 0x55, 48 MCP2221_ALT_F_NOT_GPIOV = 0xEE, 49 MCP2221_ALT_F_NOT_GPIOD = 0xEF, 50 }; 51 52 /* MCP GPIO direction encoding */ 53 enum { 54 MCP2221_DIR_OUT = 0x00, 55 MCP2221_DIR_IN = 0x01, 56 }; 57 58 #define MCP_NGPIO 4 59 60 /* MCP GPIO set command layout */ 61 struct mcp_set_gpio { 62 u8 cmd; 63 u8 dummy; 64 struct { 65 u8 change_value; 66 u8 value; 67 u8 change_direction; 68 u8 direction; 69 } gpio[MCP_NGPIO]; 70 } __packed; 71 72 /* MCP GPIO get command layout */ 73 struct mcp_get_gpio { 74 u8 cmd; 75 u8 dummy; 76 struct { 77 u8 direction; 78 u8 value; 79 } gpio[MCP_NGPIO]; 80 } __packed; 81 82 /* 83 * There is no way to distinguish responses. Therefore next command 84 * is sent only after response to previous has been received. Mutex 85 * lock is used for this purpose mainly. 86 */ 87 struct mcp2221 { 88 struct hid_device *hdev; 89 struct i2c_adapter adapter; 90 struct mutex lock; 91 struct completion wait_in_report; 92 u8 *rxbuf; 93 u8 txbuf[64]; 94 int rxbuf_idx; 95 int status; 96 u8 cur_i2c_clk_div; 97 struct gpio_chip *gc; 98 u8 gp_idx; 99 u8 gpio_dir; 100 }; 101 102 /* 103 * Default i2c bus clock frequency 400 kHz. Modify this if you 104 * want to set some other frequency (min 50 kHz - max 400 kHz). 105 */ 106 static uint i2c_clk_freq = 400; 107 108 /* Synchronously send output report to the device */ 109 static int mcp_send_report(struct mcp2221 *mcp, 110 u8 *out_report, size_t len) 111 { 112 u8 *buf; 113 int ret; 114 115 buf = kmemdup(out_report, len, GFP_KERNEL); 116 if (!buf) 117 return -ENOMEM; 118 119 /* mcp2221 uses interrupt endpoint for out reports */ 120 ret = hid_hw_output_report(mcp->hdev, buf, len); 121 kfree(buf); 122 123 if (ret < 0) 124 return ret; 125 return 0; 126 } 127 128 /* 129 * Send o/p report to the device and wait for i/p report to be 130 * received from the device. If the device does not respond, 131 * we timeout. 132 */ 133 static int mcp_send_data_req_status(struct mcp2221 *mcp, 134 u8 *out_report, int len) 135 { 136 int ret; 137 unsigned long t; 138 139 reinit_completion(&mcp->wait_in_report); 140 141 ret = mcp_send_report(mcp, out_report, len); 142 if (ret) 143 return ret; 144 145 t = wait_for_completion_timeout(&mcp->wait_in_report, 146 msecs_to_jiffies(4000)); 147 if (!t) 148 return -ETIMEDOUT; 149 150 return mcp->status; 151 } 152 153 /* Check pass/fail for actual communication with i2c slave */ 154 static int mcp_chk_last_cmd_status(struct mcp2221 *mcp) 155 { 156 memset(mcp->txbuf, 0, 8); 157 mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; 158 159 return mcp_send_data_req_status(mcp, mcp->txbuf, 8); 160 } 161 162 /* Cancels last command releasing i2c bus just in case occupied */ 163 static int mcp_cancel_last_cmd(struct mcp2221 *mcp) 164 { 165 memset(mcp->txbuf, 0, 8); 166 mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; 167 mcp->txbuf[2] = MCP2221_I2C_CANCEL; 168 169 return mcp_send_data_req_status(mcp, mcp->txbuf, 8); 170 } 171 172 static int mcp_set_i2c_speed(struct mcp2221 *mcp) 173 { 174 int ret; 175 176 memset(mcp->txbuf, 0, 8); 177 mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; 178 mcp->txbuf[3] = MCP2221_I2C_SET_SPEED; 179 mcp->txbuf[4] = mcp->cur_i2c_clk_div; 180 181 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8); 182 if (ret) { 183 /* Small delay is needed here */ 184 usleep_range(980, 1000); 185 mcp_cancel_last_cmd(mcp); 186 } 187 188 return 0; 189 } 190 191 /* 192 * An output report can contain minimum 1 and maximum 60 user data 193 * bytes. If the number of data bytes is more then 60, we send it 194 * in chunks of 60 bytes. Last chunk may contain exactly 60 or less 195 * bytes. Total number of bytes is informed in very first report to 196 * mcp2221, from that point onwards it first collect all the data 197 * from host and then send to i2c slave device. 198 */ 199 static int mcp_i2c_write(struct mcp2221 *mcp, 200 struct i2c_msg *msg, int type, u8 last_status) 201 { 202 int ret, len, idx, sent; 203 204 idx = 0; 205 sent = 0; 206 if (msg->len < 60) 207 len = msg->len; 208 else 209 len = 60; 210 211 do { 212 mcp->txbuf[0] = type; 213 mcp->txbuf[1] = msg->len & 0xff; 214 mcp->txbuf[2] = msg->len >> 8; 215 mcp->txbuf[3] = (u8)(msg->addr << 1); 216 217 memcpy(&mcp->txbuf[4], &msg->buf[idx], len); 218 219 ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4); 220 if (ret) 221 return ret; 222 223 usleep_range(980, 1000); 224 225 if (last_status) { 226 ret = mcp_chk_last_cmd_status(mcp); 227 if (ret) 228 return ret; 229 } 230 231 sent = sent + len; 232 if (sent >= msg->len) 233 break; 234 235 idx = idx + len; 236 if ((msg->len - sent) < 60) 237 len = msg->len - sent; 238 else 239 len = 60; 240 241 /* 242 * Testing shows delay is needed between successive writes 243 * otherwise next write fails on first-try from i2c core. 244 * This value is obtained through automated stress testing. 245 */ 246 usleep_range(980, 1000); 247 } while (len > 0); 248 249 return ret; 250 } 251 252 /* 253 * Device reads all data (0 - 65535 bytes) from i2c slave device and 254 * stores it in device itself. This data is read back from device to 255 * host in multiples of 60 bytes using input reports. 256 */ 257 static int mcp_i2c_smbus_read(struct mcp2221 *mcp, 258 struct i2c_msg *msg, int type, u16 smbus_addr, 259 u8 smbus_len, u8 *smbus_buf) 260 { 261 int ret; 262 u16 total_len; 263 264 mcp->txbuf[0] = type; 265 if (msg) { 266 mcp->txbuf[1] = msg->len & 0xff; 267 mcp->txbuf[2] = msg->len >> 8; 268 mcp->txbuf[3] = (u8)(msg->addr << 1); 269 total_len = msg->len; 270 mcp->rxbuf = msg->buf; 271 } else { 272 mcp->txbuf[1] = smbus_len; 273 mcp->txbuf[2] = 0; 274 mcp->txbuf[3] = (u8)(smbus_addr << 1); 275 total_len = smbus_len; 276 mcp->rxbuf = smbus_buf; 277 } 278 279 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4); 280 if (ret) 281 return ret; 282 283 mcp->rxbuf_idx = 0; 284 285 do { 286 memset(mcp->txbuf, 0, 4); 287 mcp->txbuf[0] = MCP2221_I2C_GET_DATA; 288 289 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); 290 if (ret) 291 return ret; 292 293 ret = mcp_chk_last_cmd_status(mcp); 294 if (ret) 295 return ret; 296 297 usleep_range(980, 1000); 298 } while (mcp->rxbuf_idx < total_len); 299 300 return ret; 301 } 302 303 static int mcp_i2c_xfer(struct i2c_adapter *adapter, 304 struct i2c_msg msgs[], int num) 305 { 306 int ret; 307 struct mcp2221 *mcp = i2c_get_adapdata(adapter); 308 309 hid_hw_power(mcp->hdev, PM_HINT_FULLON); 310 311 mutex_lock(&mcp->lock); 312 313 /* Setting speed before every transaction is required for mcp2221 */ 314 ret = mcp_set_i2c_speed(mcp); 315 if (ret) 316 goto exit; 317 318 if (num == 1) { 319 if (msgs->flags & I2C_M_RD) { 320 ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, 321 0, 0, NULL); 322 } else { 323 ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); 324 } 325 if (ret) 326 goto exit; 327 ret = num; 328 } else if (num == 2) { 329 /* Ex transaction; send reg address and read its contents */ 330 if (msgs[0].addr == msgs[1].addr && 331 !(msgs[0].flags & I2C_M_RD) && 332 (msgs[1].flags & I2C_M_RD)) { 333 334 ret = mcp_i2c_write(mcp, &msgs[0], 335 MCP2221_I2C_WR_NO_STOP, 0); 336 if (ret) 337 goto exit; 338 339 ret = mcp_i2c_smbus_read(mcp, &msgs[1], 340 MCP2221_I2C_RD_RPT_START, 341 0, 0, NULL); 342 if (ret) 343 goto exit; 344 ret = num; 345 } else { 346 dev_err(&adapter->dev, 347 "unsupported multi-msg i2c transaction\n"); 348 ret = -EOPNOTSUPP; 349 } 350 } else { 351 dev_err(&adapter->dev, 352 "unsupported multi-msg i2c transaction\n"); 353 ret = -EOPNOTSUPP; 354 } 355 356 exit: 357 hid_hw_power(mcp->hdev, PM_HINT_NORMAL); 358 mutex_unlock(&mcp->lock); 359 return ret; 360 } 361 362 static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr, 363 u8 command, u8 *buf, u8 len, int type, 364 u8 last_status) 365 { 366 int data_len, ret; 367 368 mcp->txbuf[0] = type; 369 mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */ 370 mcp->txbuf[2] = 0; 371 mcp->txbuf[3] = (u8)(addr << 1); 372 mcp->txbuf[4] = command; 373 374 switch (len) { 375 case 0: 376 data_len = 5; 377 break; 378 case 1: 379 mcp->txbuf[5] = buf[0]; 380 data_len = 6; 381 break; 382 case 2: 383 mcp->txbuf[5] = buf[0]; 384 mcp->txbuf[6] = buf[1]; 385 data_len = 7; 386 break; 387 default: 388 memcpy(&mcp->txbuf[5], buf, len); 389 data_len = len + 5; 390 } 391 392 ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len); 393 if (ret) 394 return ret; 395 396 if (last_status) { 397 usleep_range(980, 1000); 398 399 ret = mcp_chk_last_cmd_status(mcp); 400 if (ret) 401 return ret; 402 } 403 404 return ret; 405 } 406 407 static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 408 unsigned short flags, char read_write, 409 u8 command, int size, 410 union i2c_smbus_data *data) 411 { 412 int ret; 413 struct mcp2221 *mcp = i2c_get_adapdata(adapter); 414 415 hid_hw_power(mcp->hdev, PM_HINT_FULLON); 416 417 mutex_lock(&mcp->lock); 418 419 ret = mcp_set_i2c_speed(mcp); 420 if (ret) 421 goto exit; 422 423 switch (size) { 424 425 case I2C_SMBUS_QUICK: 426 if (read_write == I2C_SMBUS_READ) 427 ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, 428 addr, 0, &data->byte); 429 else 430 ret = mcp_smbus_write(mcp, addr, command, NULL, 431 0, MCP2221_I2C_WR_DATA, 1); 432 break; 433 case I2C_SMBUS_BYTE: 434 if (read_write == I2C_SMBUS_READ) 435 ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, 436 addr, 1, &data->byte); 437 else 438 ret = mcp_smbus_write(mcp, addr, command, NULL, 439 0, MCP2221_I2C_WR_DATA, 1); 440 break; 441 case I2C_SMBUS_BYTE_DATA: 442 if (read_write == I2C_SMBUS_READ) { 443 ret = mcp_smbus_write(mcp, addr, command, NULL, 444 0, MCP2221_I2C_WR_NO_STOP, 0); 445 if (ret) 446 goto exit; 447 448 ret = mcp_i2c_smbus_read(mcp, NULL, 449 MCP2221_I2C_RD_RPT_START, 450 addr, 1, &data->byte); 451 } else { 452 ret = mcp_smbus_write(mcp, addr, command, &data->byte, 453 1, MCP2221_I2C_WR_DATA, 1); 454 } 455 break; 456 case I2C_SMBUS_WORD_DATA: 457 if (read_write == I2C_SMBUS_READ) { 458 ret = mcp_smbus_write(mcp, addr, command, NULL, 459 0, MCP2221_I2C_WR_NO_STOP, 0); 460 if (ret) 461 goto exit; 462 463 ret = mcp_i2c_smbus_read(mcp, NULL, 464 MCP2221_I2C_RD_RPT_START, 465 addr, 2, (u8 *)&data->word); 466 } else { 467 ret = mcp_smbus_write(mcp, addr, command, 468 (u8 *)&data->word, 2, 469 MCP2221_I2C_WR_DATA, 1); 470 } 471 break; 472 case I2C_SMBUS_BLOCK_DATA: 473 if (read_write == I2C_SMBUS_READ) { 474 ret = mcp_smbus_write(mcp, addr, command, NULL, 475 0, MCP2221_I2C_WR_NO_STOP, 1); 476 if (ret) 477 goto exit; 478 479 mcp->rxbuf_idx = 0; 480 mcp->rxbuf = data->block; 481 mcp->txbuf[0] = MCP2221_I2C_GET_DATA; 482 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); 483 if (ret) 484 goto exit; 485 } else { 486 if (!data->block[0]) { 487 ret = -EINVAL; 488 goto exit; 489 } 490 ret = mcp_smbus_write(mcp, addr, command, data->block, 491 data->block[0] + 1, 492 MCP2221_I2C_WR_DATA, 1); 493 } 494 break; 495 case I2C_SMBUS_I2C_BLOCK_DATA: 496 if (read_write == I2C_SMBUS_READ) { 497 ret = mcp_smbus_write(mcp, addr, command, NULL, 498 0, MCP2221_I2C_WR_NO_STOP, 1); 499 if (ret) 500 goto exit; 501 502 mcp->rxbuf_idx = 0; 503 mcp->rxbuf = data->block; 504 mcp->txbuf[0] = MCP2221_I2C_GET_DATA; 505 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); 506 if (ret) 507 goto exit; 508 } else { 509 if (!data->block[0]) { 510 ret = -EINVAL; 511 goto exit; 512 } 513 ret = mcp_smbus_write(mcp, addr, command, 514 &data->block[1], data->block[0], 515 MCP2221_I2C_WR_DATA, 1); 516 } 517 break; 518 case I2C_SMBUS_PROC_CALL: 519 ret = mcp_smbus_write(mcp, addr, command, 520 (u8 *)&data->word, 521 2, MCP2221_I2C_WR_NO_STOP, 0); 522 if (ret) 523 goto exit; 524 525 ret = mcp_i2c_smbus_read(mcp, NULL, 526 MCP2221_I2C_RD_RPT_START, 527 addr, 2, (u8 *)&data->word); 528 break; 529 case I2C_SMBUS_BLOCK_PROC_CALL: 530 ret = mcp_smbus_write(mcp, addr, command, data->block, 531 data->block[0] + 1, 532 MCP2221_I2C_WR_NO_STOP, 0); 533 if (ret) 534 goto exit; 535 536 ret = mcp_i2c_smbus_read(mcp, NULL, 537 MCP2221_I2C_RD_RPT_START, 538 addr, I2C_SMBUS_BLOCK_MAX, 539 data->block); 540 break; 541 default: 542 dev_err(&mcp->adapter.dev, 543 "unsupported smbus transaction size:%d\n", size); 544 ret = -EOPNOTSUPP; 545 } 546 547 exit: 548 hid_hw_power(mcp->hdev, PM_HINT_NORMAL); 549 mutex_unlock(&mcp->lock); 550 return ret; 551 } 552 553 static u32 mcp_i2c_func(struct i2c_adapter *adapter) 554 { 555 return I2C_FUNC_I2C | 556 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 557 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 558 (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC); 559 } 560 561 static const struct i2c_algorithm mcp_i2c_algo = { 562 .master_xfer = mcp_i2c_xfer, 563 .smbus_xfer = mcp_smbus_xfer, 564 .functionality = mcp_i2c_func, 565 }; 566 567 static int mcp_gpio_get(struct gpio_chip *gc, 568 unsigned int offset) 569 { 570 int ret; 571 struct mcp2221 *mcp = gpiochip_get_data(gc); 572 573 mcp->txbuf[0] = MCP2221_GPIO_GET; 574 575 mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset].value); 576 577 mutex_lock(&mcp->lock); 578 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); 579 mutex_unlock(&mcp->lock); 580 581 return ret; 582 } 583 584 static void mcp_gpio_set(struct gpio_chip *gc, 585 unsigned int offset, int value) 586 { 587 struct mcp2221 *mcp = gpiochip_get_data(gc); 588 589 memset(mcp->txbuf, 0, 18); 590 mcp->txbuf[0] = MCP2221_GPIO_SET; 591 592 mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].value); 593 594 mcp->txbuf[mcp->gp_idx - 1] = 1; 595 mcp->txbuf[mcp->gp_idx] = !!value; 596 597 mutex_lock(&mcp->lock); 598 mcp_send_data_req_status(mcp, mcp->txbuf, 18); 599 mutex_unlock(&mcp->lock); 600 } 601 602 static int mcp_gpio_dir_set(struct mcp2221 *mcp, 603 unsigned int offset, u8 val) 604 { 605 memset(mcp->txbuf, 0, 18); 606 mcp->txbuf[0] = MCP2221_GPIO_SET; 607 608 mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].direction); 609 610 mcp->txbuf[mcp->gp_idx - 1] = 1; 611 mcp->txbuf[mcp->gp_idx] = val; 612 613 return mcp_send_data_req_status(mcp, mcp->txbuf, 18); 614 } 615 616 static int mcp_gpio_direction_input(struct gpio_chip *gc, 617 unsigned int offset) 618 { 619 int ret; 620 struct mcp2221 *mcp = gpiochip_get_data(gc); 621 622 mutex_lock(&mcp->lock); 623 ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_IN); 624 mutex_unlock(&mcp->lock); 625 626 return ret; 627 } 628 629 static int mcp_gpio_direction_output(struct gpio_chip *gc, 630 unsigned int offset, int value) 631 { 632 int ret; 633 struct mcp2221 *mcp = gpiochip_get_data(gc); 634 635 mutex_lock(&mcp->lock); 636 ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_OUT); 637 mutex_unlock(&mcp->lock); 638 639 /* Can't configure as output, bailout early */ 640 if (ret) 641 return ret; 642 643 mcp_gpio_set(gc, offset, value); 644 645 return 0; 646 } 647 648 static int mcp_gpio_get_direction(struct gpio_chip *gc, 649 unsigned int offset) 650 { 651 int ret; 652 struct mcp2221 *mcp = gpiochip_get_data(gc); 653 654 mcp->txbuf[0] = MCP2221_GPIO_GET; 655 656 mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset].direction); 657 658 mutex_lock(&mcp->lock); 659 ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); 660 mutex_unlock(&mcp->lock); 661 662 if (ret) 663 return ret; 664 665 if (mcp->gpio_dir == MCP2221_DIR_IN) 666 return GPIO_LINE_DIRECTION_IN; 667 668 return GPIO_LINE_DIRECTION_OUT; 669 } 670 671 /* Gives current state of i2c engine inside mcp2221 */ 672 static int mcp_get_i2c_eng_state(struct mcp2221 *mcp, 673 u8 *data, u8 idx) 674 { 675 int ret; 676 677 switch (data[idx]) { 678 case MCP2221_I2C_WRADDRL_NACK: 679 case MCP2221_I2C_WRADDRL_SEND: 680 ret = -ENXIO; 681 break; 682 case MCP2221_I2C_START_TOUT: 683 case MCP2221_I2C_STOP_TOUT: 684 case MCP2221_I2C_WRADDRL_TOUT: 685 case MCP2221_I2C_WRDATA_TOUT: 686 ret = -ETIMEDOUT; 687 break; 688 case MCP2221_I2C_ENG_BUSY: 689 ret = -EAGAIN; 690 break; 691 case MCP2221_SUCCESS: 692 ret = 0x00; 693 break; 694 default: 695 ret = -EIO; 696 } 697 698 return ret; 699 } 700 701 /* 702 * MCP2221 uses interrupt endpoint for input reports. This function 703 * is called by HID layer when it receives i/p report from mcp2221, 704 * which is actually a response to the previously sent command. 705 * 706 * MCP2221A firmware specific return codes are parsed and 0 or 707 * appropriate negative error code is returned. Delayed response 708 * results in timeout error and stray reponses results in -EIO. 709 */ 710 static int mcp2221_raw_event(struct hid_device *hdev, 711 struct hid_report *report, u8 *data, int size) 712 { 713 u8 *buf; 714 struct mcp2221 *mcp = hid_get_drvdata(hdev); 715 716 switch (data[0]) { 717 718 case MCP2221_I2C_WR_DATA: 719 case MCP2221_I2C_WR_NO_STOP: 720 case MCP2221_I2C_RD_DATA: 721 case MCP2221_I2C_RD_RPT_START: 722 switch (data[1]) { 723 case MCP2221_SUCCESS: 724 mcp->status = 0; 725 break; 726 default: 727 mcp->status = mcp_get_i2c_eng_state(mcp, data, 2); 728 } 729 complete(&mcp->wait_in_report); 730 break; 731 732 case MCP2221_I2C_PARAM_OR_STATUS: 733 switch (data[1]) { 734 case MCP2221_SUCCESS: 735 if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) && 736 (data[3] != MCP2221_I2C_SET_SPEED)) { 737 mcp->status = -EAGAIN; 738 break; 739 } 740 if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) { 741 mcp->status = -ENXIO; 742 break; 743 } 744 mcp->status = mcp_get_i2c_eng_state(mcp, data, 8); 745 break; 746 default: 747 mcp->status = -EIO; 748 } 749 complete(&mcp->wait_in_report); 750 break; 751 752 case MCP2221_I2C_GET_DATA: 753 switch (data[1]) { 754 case MCP2221_SUCCESS: 755 if (data[2] == MCP2221_I2C_ADDR_NACK) { 756 mcp->status = -ENXIO; 757 break; 758 } 759 if (!mcp_get_i2c_eng_state(mcp, data, 2) 760 && (data[3] == 0)) { 761 mcp->status = 0; 762 break; 763 } 764 if (data[3] == 127) { 765 mcp->status = -EIO; 766 break; 767 } 768 if (data[2] == MCP2221_I2C_READ_COMPL) { 769 buf = mcp->rxbuf; 770 memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]); 771 mcp->rxbuf_idx = mcp->rxbuf_idx + data[3]; 772 mcp->status = 0; 773 break; 774 } 775 mcp->status = -EIO; 776 break; 777 default: 778 mcp->status = -EIO; 779 } 780 complete(&mcp->wait_in_report); 781 break; 782 783 case MCP2221_GPIO_GET: 784 switch (data[1]) { 785 case MCP2221_SUCCESS: 786 if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) || 787 (data[mcp->gp_idx + 1] == MCP2221_ALT_F_NOT_GPIOD)) { 788 mcp->status = -ENOENT; 789 } else { 790 mcp->status = !!data[mcp->gp_idx]; 791 mcp->gpio_dir = data[mcp->gp_idx + 1]; 792 } 793 break; 794 default: 795 mcp->status = -EAGAIN; 796 } 797 complete(&mcp->wait_in_report); 798 break; 799 800 case MCP2221_GPIO_SET: 801 switch (data[1]) { 802 case MCP2221_SUCCESS: 803 if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) || 804 (data[mcp->gp_idx - 1] == MCP2221_ALT_F_NOT_GPIOV)) { 805 mcp->status = -ENOENT; 806 } else { 807 mcp->status = 0; 808 } 809 break; 810 default: 811 mcp->status = -EAGAIN; 812 } 813 complete(&mcp->wait_in_report); 814 break; 815 816 default: 817 mcp->status = -EIO; 818 complete(&mcp->wait_in_report); 819 } 820 821 return 1; 822 } 823 824 static int mcp2221_probe(struct hid_device *hdev, 825 const struct hid_device_id *id) 826 { 827 int ret; 828 struct mcp2221 *mcp; 829 830 mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL); 831 if (!mcp) 832 return -ENOMEM; 833 834 ret = hid_parse(hdev); 835 if (ret) { 836 hid_err(hdev, "can't parse reports\n"); 837 return ret; 838 } 839 840 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); 841 if (ret) { 842 hid_err(hdev, "can't start hardware\n"); 843 return ret; 844 } 845 846 ret = hid_hw_open(hdev); 847 if (ret) { 848 hid_err(hdev, "can't open device\n"); 849 goto err_hstop; 850 } 851 852 mutex_init(&mcp->lock); 853 init_completion(&mcp->wait_in_report); 854 hid_set_drvdata(hdev, mcp); 855 mcp->hdev = hdev; 856 857 /* Set I2C bus clock diviser */ 858 if (i2c_clk_freq > 400) 859 i2c_clk_freq = 400; 860 if (i2c_clk_freq < 50) 861 i2c_clk_freq = 50; 862 mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3; 863 864 mcp->adapter.owner = THIS_MODULE; 865 mcp->adapter.class = I2C_CLASS_HWMON; 866 mcp->adapter.algo = &mcp_i2c_algo; 867 mcp->adapter.retries = 1; 868 mcp->adapter.dev.parent = &hdev->dev; 869 snprintf(mcp->adapter.name, sizeof(mcp->adapter.name), 870 "MCP2221 usb-i2c bridge on hidraw%d", 871 ((struct hidraw *)hdev->hidraw)->minor); 872 873 ret = i2c_add_adapter(&mcp->adapter); 874 if (ret) { 875 hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret); 876 goto err_i2c; 877 } 878 i2c_set_adapdata(&mcp->adapter, mcp); 879 880 /* Setup GPIO chip */ 881 mcp->gc = devm_kzalloc(&hdev->dev, sizeof(*mcp->gc), GFP_KERNEL); 882 if (!mcp->gc) { 883 ret = -ENOMEM; 884 goto err_gc; 885 } 886 887 mcp->gc->label = "mcp2221_gpio"; 888 mcp->gc->direction_input = mcp_gpio_direction_input; 889 mcp->gc->direction_output = mcp_gpio_direction_output; 890 mcp->gc->get_direction = mcp_gpio_get_direction; 891 mcp->gc->set = mcp_gpio_set; 892 mcp->gc->get = mcp_gpio_get; 893 mcp->gc->ngpio = MCP_NGPIO; 894 mcp->gc->base = -1; 895 mcp->gc->can_sleep = 1; 896 mcp->gc->parent = &hdev->dev; 897 898 ret = devm_gpiochip_add_data(&hdev->dev, mcp->gc, mcp); 899 if (ret) 900 goto err_gc; 901 902 return 0; 903 904 err_gc: 905 i2c_del_adapter(&mcp->adapter); 906 err_i2c: 907 hid_hw_close(mcp->hdev); 908 err_hstop: 909 hid_hw_stop(mcp->hdev); 910 return ret; 911 } 912 913 static void mcp2221_remove(struct hid_device *hdev) 914 { 915 struct mcp2221 *mcp = hid_get_drvdata(hdev); 916 917 i2c_del_adapter(&mcp->adapter); 918 hid_hw_close(mcp->hdev); 919 hid_hw_stop(mcp->hdev); 920 } 921 922 static const struct hid_device_id mcp2221_devices[] = { 923 { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) }, 924 { } 925 }; 926 MODULE_DEVICE_TABLE(hid, mcp2221_devices); 927 928 static struct hid_driver mcp2221_driver = { 929 .name = "mcp2221", 930 .id_table = mcp2221_devices, 931 .probe = mcp2221_probe, 932 .remove = mcp2221_remove, 933 .raw_event = mcp2221_raw_event, 934 }; 935 936 /* Register with HID core */ 937 module_hid_driver(mcp2221_driver); 938 939 MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>"); 940 MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge"); 941 MODULE_LICENSE("GPL v2"); 942