drivers/hid/hid-cp2112.c

   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  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
  25  */
  26
  27 #include <linux/gpio.h>
  28 #include <linux/gpio/driver.h>
  29 #include <linux/hid.h>
  30 #include <linux/hidraw.h>
  31 #include <linux/i2c.h>
  32 #include <linux/module.h>
  33 #include <linux/nls.h>
  34 #include <linux/usb/ch9.h>
  35 #include "hid-ids.h"
  36
  37 #define CP2112_REPORT_MAX_LENGTH                64
  38 #define CP2112_GPIO_CONFIG_LENGTH               5
  39 #define CP2112_GPIO_GET_LENGTH                  2
  40 #define CP2112_GPIO_SET_LENGTH                  3
  41
  42 enum {
  43         CP2112_GPIO_CONFIG              = 0x02,
  44         CP2112_GPIO_GET                 = 0x03,
  45         CP2112_GPIO_SET                 = 0x04,
  46         CP2112_GET_VERSION_INFO         = 0x05,
  47         CP2112_SMBUS_CONFIG             = 0x06,
  48         CP2112_DATA_READ_REQUEST        = 0x10,
  49         CP2112_DATA_WRITE_READ_REQUEST  = 0x11,
  50         CP2112_DATA_READ_FORCE_SEND     = 0x12,
  51         CP2112_DATA_READ_RESPONSE       = 0x13,
  52         CP2112_DATA_WRITE_REQUEST       = 0x14,
  53         CP2112_TRANSFER_STATUS_REQUEST  = 0x15,
  54         CP2112_TRANSFER_STATUS_RESPONSE = 0x16,
  55         CP2112_CANCEL_TRANSFER          = 0x17,
  56         CP2112_LOCK_BYTE                = 0x20,
  57         CP2112_USB_CONFIG               = 0x21,
  58         CP2112_MANUFACTURER_STRING      = 0x22,
  59         CP2112_PRODUCT_STRING           = 0x23,
  60         CP2112_SERIAL_STRING            = 0x24,
  61 };
  62
  63 enum {
  64         STATUS0_IDLE            = 0x00,
  65         STATUS0_BUSY            = 0x01,
  66         STATUS0_COMPLETE        = 0x02,
  67         STATUS0_ERROR           = 0x03,
  68 };
  69
  70 enum {
  71         STATUS1_TIMEOUT_NACK            = 0x00,
  72         STATUS1_TIMEOUT_BUS             = 0x01,
  73         STATUS1_ARBITRATION_LOST        = 0x02,
  74         STATUS1_READ_INCOMPLETE         = 0x03,
  75         STATUS1_WRITE_INCOMPLETE        = 0x04,
  76         STATUS1_SUCCESS                 = 0x05,
  77 };
  78
  79 struct cp2112_smbus_config_report {
  80         u8 report;              /* CP2112_SMBUS_CONFIG */
  81         __be32 clock_speed;     /* Hz */
  82         u8 device_address;      /* Stored in the upper 7 bits */
  83         u8 auto_send_read;      /* 1 = enabled, 0 = disabled */
  84         __be16 write_timeout;   /* ms, 0 = no timeout */
  85         __be16 read_timeout;    /* ms, 0 = no timeout */
  86         u8 scl_low_timeout;     /* 1 = enabled, 0 = disabled */
  87         __be16 retry_time;      /* # of retries, 0 = no limit */
  88 } __packed;
  89
  90 struct cp2112_usb_config_report {
  91         u8 report;      /* CP2112_USB_CONFIG */
  92         __le16 vid;     /* Vendor ID */
  93         __le16 pid;     /* Product ID */
  94         u8 max_power;   /* Power requested in 2mA units */
  95         u8 power_mode;  /* 0x00 = bus powered
  96                            0x01 = self powered & regulator off
  97                            0x02 = self powered & regulator on */
  98         u8 release_major;
  99         u8 release_minor;
 100         u8 mask;        /* What fields to program */
 101 } __packed;
 102
 103 struct cp2112_read_req_report {
 104         u8 report;      /* CP2112_DATA_READ_REQUEST */
 105         u8 slave_address;
 106         __be16 length;
 107 } __packed;
 108
 109 struct cp2112_write_read_req_report {
 110         u8 report;      /* CP2112_DATA_WRITE_READ_REQUEST */
 111         u8 slave_address;
 112         __be16 length;
 113         u8 target_address_length;
 114         u8 target_address[16];
 115 } __packed;
 116
 117 struct cp2112_write_req_report {
 118         u8 report;      /* CP2112_DATA_WRITE_REQUEST */
 119         u8 slave_address;
 120         u8 length;
 121         u8 data[61];
 122 } __packed;
 123
 124 struct cp2112_force_read_report {
 125         u8 report;      /* CP2112_DATA_READ_FORCE_SEND */
 126         __be16 length;
 127 } __packed;
 128
 129 struct cp2112_xfer_status_report {
 130         u8 report;      /* CP2112_TRANSFER_STATUS_RESPONSE */
 131         u8 status0;     /* STATUS0_* */
 132         u8 status1;     /* STATUS1_* */
 133         __be16 retries;
 134         __be16 length;
 135 } __packed;
 136
 137 struct cp2112_string_report {
 138         u8 dummy;               /* force .string to be aligned */
 139         u8 report;              /* CP2112_*_STRING */
 140         u8 length;              /* length in bytes of everyting after .report */
 141         u8 type;                /* USB_DT_STRING */
 142         wchar_t string[30];     /* UTF16_LITTLE_ENDIAN string */
 143 } __packed;
 144
 145 /* Number of times to request transfer status before giving up waiting for a
 146    transfer to complete. This may need to be changed if SMBUS clock, retries,
 147    or read/write/scl_low timeout settings are changed. */
 148 static const int XFER_STATUS_RETRIES = 10;
 149
 150 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
 151    CP2112_TRANSFER_STATUS_RESPONSE. */
 152 static const int RESPONSE_TIMEOUT = 50;
 153
 154 static const struct hid_device_id cp2112_devices[] = {
 155         { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
 156         { }
 157 };
 158 MODULE_DEVICE_TABLE(hid, cp2112_devices);
 159
 160 struct cp2112_device {
 161         struct i2c_adapter adap;
 162         struct hid_device *hdev;
 163         wait_queue_head_t wait;
 164         u8 read_data[61];
 165         u8 read_length;
 166         u8 hwversion;
 167         int xfer_status;
 168         atomic_t read_avail;
 169         atomic_t xfer_avail;
 170         struct gpio_chip gc;
 171         u8 *in_out_buffer;
 172         struct mutex lock;
 173
 174         struct gpio_desc *desc[8];
 175         bool gpio_poll;
 176         struct delayed_work gpio_poll_worker;
 177         unsigned long irq_mask;
 178         u8 gpio_prev_state;
 179 };
 180
 181 static int gpio_push_pull = 0xFF;
 182 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
 183 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
 184
 185 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 186 {
 187         struct cp2112_device *dev = gpiochip_get_data(chip);
 188         struct hid_device *hdev = dev->hdev;
 189         u8 *buf = dev->in_out_buffer;
 190         int ret;
 191
 192         mutex_lock(&dev->lock);
 193
 194         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 195                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 196                                  HID_REQ_GET_REPORT);
 197         if (ret != CP2112_GPIO_CONFIG_LENGTH) {
 198                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 199                 if (ret >= 0)
 200                         ret = -EIO;
 201                 goto exit;
 202         }
 203
 204         buf[1] &= ~(1 << offset);
 205         buf[2] = gpio_push_pull;
 206
 207         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 208                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 209                                  HID_REQ_SET_REPORT);
 210         if (ret != CP2112_GPIO_CONFIG_LENGTH) {
 211                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 212                 if (ret >= 0)
 213                         ret = -EIO;
 214                 goto exit;
 215         }
 216
 217         ret = 0;
 218
 219 exit:
 220         mutex_unlock(&dev->lock);
 221         return ret;
 222 }
 223
 224 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 225 {
 226         struct cp2112_device *dev = gpiochip_get_data(chip);
 227         struct hid_device *hdev = dev->hdev;
 228         u8 *buf = dev->in_out_buffer;
 229         int ret;
 230
 231         mutex_lock(&dev->lock);
 232
 233         buf[0] = CP2112_GPIO_SET;
 234         buf[1] = value ? 0xff : 0;
 235         buf[2] = 1 << offset;
 236
 237         ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
 238                                  CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
 239                                  HID_REQ_SET_REPORT);
 240         if (ret < 0)
 241                 hid_err(hdev, "error setting GPIO values: %d\n", ret);
 242
 243         mutex_unlock(&dev->lock);
 244 }
 245
 246 static int cp2112_gpio_get_all(struct gpio_chip *chip)
 247 {
 248         struct cp2112_device *dev = gpiochip_get_data(chip);
 249         struct hid_device *hdev = dev->hdev;
 250         u8 *buf = dev->in_out_buffer;
 251         int ret;
 252
 253         mutex_lock(&dev->lock);
 254
 255         ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
 256                                  CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
 257                                  HID_REQ_GET_REPORT);
 258         if (ret != CP2112_GPIO_GET_LENGTH) {
 259                 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
 260                 ret = ret < 0 ? ret : -EIO;
 261                 goto exit;
 262         }
 263
 264         ret = buf[1];
 265
 266 exit:
 267         mutex_unlock(&dev->lock);
 268
 269         return ret;
 270 }
 271
 272 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
 273 {
 274         int ret;
 275
 276         ret = cp2112_gpio_get_all(chip);
 277         if (ret < 0)
 278                 return ret;
 279
 280         return (ret >> offset) & 1;
 281 }
 282
 283 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
 284                                         unsigned offset, int value)
 285 {
 286         struct cp2112_device *dev = gpiochip_get_data(chip);
 287         struct hid_device *hdev = dev->hdev;
 288         u8 *buf = dev->in_out_buffer;
 289         int ret;
 290
 291         mutex_lock(&dev->lock);
 292
 293         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 294                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 295                                  HID_REQ_GET_REPORT);
 296         if (ret != CP2112_GPIO_CONFIG_LENGTH) {
 297                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 298                 goto fail;
 299         }
 300
 301         buf[1] |= 1 << offset;
 302         buf[2] = gpio_push_pull;
 303
 304         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 305                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 306                                  HID_REQ_SET_REPORT);
 307         if (ret < 0) {
 308                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 309                 goto fail;
 310         }
 311
 312         mutex_unlock(&dev->lock);
 313
 314         /*
 315          * Set gpio value when output direction is already set,
 316          * as specified in AN495, Rev. 0.2, cpt. 4.4
 317          */
 318         cp2112_gpio_set(chip, offset, value);
 319
 320         return 0;
 321
 322 fail:
 323         mutex_unlock(&dev->lock);
 324         return ret < 0 ? ret : -EIO;
 325 }
 326
 327 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
 328                           u8 *data, size_t count, unsigned char report_type)
 329 {
 330         u8 *buf;
 331         int ret;
 332
 333         buf = kmalloc(count, GFP_KERNEL);
 334         if (!buf)
 335                 return -ENOMEM;
 336
 337         ret = hid_hw_raw_request(hdev, report_number, buf, count,
 338                                        report_type, HID_REQ_GET_REPORT);
 339         memcpy(data, buf, count);
 340         kfree(buf);
 341         return ret;
 342 }
 343
 344 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
 345                              unsigned char report_type)
 346 {
 347         u8 *buf;
 348         int ret;
 349
 350         buf = kmemdup(data, count, GFP_KERNEL);
 351         if (!buf)
 352                 return -ENOMEM;
 353
 354         if (report_type == HID_OUTPUT_REPORT)
 355                 ret = hid_hw_output_report(hdev, buf, count);
 356         else
 357                 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
 358                                 HID_REQ_SET_REPORT);
 359
 360         kfree(buf);
 361         return ret;
 362 }
 363
 364 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
 365 {
 366         int ret = 0;
 367
 368         /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
 369          * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
 370          * come in cp2112_raw_event or timeout. There will only be one of these
 371          * in flight at any one time. The timeout is extremely large and is a
 372          * last resort if the CP2112 has died. If we do timeout we don't expect
 373          * to receive the response which would cause data races, it's not like
 374          * we can do anything about it anyway.
 375          */
 376         ret = wait_event_interruptible_timeout(dev->wait,
 377                 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
 378         if (-ERESTARTSYS == ret)
 379                 return ret;
 380         if (!ret)
 381                 return -ETIMEDOUT;
 382
 383         atomic_set(avail, 0);
 384         return 0;
 385 }
 386
 387 static int cp2112_xfer_status(struct cp2112_device *dev)
 388 {
 389         struct hid_device *hdev = dev->hdev;
 390         u8 buf[2];
 391         int ret;
 392
 393         buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
 394         buf[1] = 0x01;
 395         atomic_set(&dev->xfer_avail, 0);
 396
 397         ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 398         if (ret < 0) {
 399                 hid_warn(hdev, "Error requesting status: %d\n", ret);
 400                 return ret;
 401         }
 402
 403         ret = cp2112_wait(dev, &dev->xfer_avail);
 404         if (ret)
 405                 return ret;
 406
 407         return dev->xfer_status;
 408 }
 409
 410 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 411 {
 412         struct hid_device *hdev = dev->hdev;
 413         struct cp2112_force_read_report report;
 414         int ret;
 415
 416         if (size > sizeof(dev->read_data))
 417                 size = sizeof(dev->read_data);
 418         report.report = CP2112_DATA_READ_FORCE_SEND;
 419         report.length = cpu_to_be16(size);
 420
 421         atomic_set(&dev->read_avail, 0);
 422
 423         ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
 424                                 HID_OUTPUT_REPORT);
 425         if (ret < 0) {
 426                 hid_warn(hdev, "Error requesting data: %d\n", ret);
 427                 return ret;
 428         }
 429
 430         ret = cp2112_wait(dev, &dev->read_avail);
 431         if (ret)
 432                 return ret;
 433
 434         hid_dbg(hdev, "read %d of %zd bytes requested\n",
 435                 dev->read_length, size);
 436
 437         if (size > dev->read_length)
 438                 size = dev->read_length;
 439
 440         memcpy(data, dev->read_data, size);
 441         return dev->read_length;
 442 }
 443
 444 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
 445 {
 446         struct cp2112_read_req_report *report = buf;
 447
 448         if (length < 1 || length > 512)
 449                 return -EINVAL;
 450
 451         report->report = CP2112_DATA_READ_REQUEST;
 452         report->slave_address = slave_address << 1;
 453         report->length = cpu_to_be16(length);
 454         return sizeof(*report);
 455 }
 456
 457 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
 458                                  u8 command, u8 *data, u8 data_length)
 459 {
 460         struct cp2112_write_read_req_report *report = buf;
 461
 462         if (length < 1 || length > 512
 463             || data_length > sizeof(report->target_address) - 1)
 464                 return -EINVAL;
 465
 466         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 467         report->slave_address = slave_address << 1;
 468         report->length = cpu_to_be16(length);
 469         report->target_address_length = data_length + 1;
 470         report->target_address[0] = command;
 471         memcpy(&report->target_address[1], data, data_length);
 472         return data_length + 6;
 473 }
 474
 475 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
 476                             u8 data_length)
 477 {
 478         struct cp2112_write_req_report *report = buf;
 479
 480         if (data_length > sizeof(report->data) - 1)
 481                 return -EINVAL;
 482
 483         report->report = CP2112_DATA_WRITE_REQUEST;
 484         report->slave_address = slave_address << 1;
 485         report->length = data_length + 1;
 486         report->data[0] = command;
 487         memcpy(&report->data[1], data, data_length);
 488         return data_length + 4;
 489 }
 490
 491 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
 492                                 u8 data_length)
 493 {
 494         struct cp2112_write_req_report *report = buf;
 495
 496         if (data_length > sizeof(report->data))
 497                 return -EINVAL;
 498
 499         report->report = CP2112_DATA_WRITE_REQUEST;
 500         report->slave_address = slave_address << 1;
 501         report->length = data_length;
 502         memcpy(report->data, data, data_length);
 503         return data_length + 3;
 504 }
 505
 506 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
 507                                      u8 *addr, int addr_length,
 508                                      int read_length)
 509 {
 510         struct cp2112_write_read_req_report *report = buf;
 511
 512         if (read_length < 1 || read_length > 512 ||
 513             addr_length > sizeof(report->target_address))
 514                 return -EINVAL;
 515
 516         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 517         report->slave_address = slave_address << 1;
 518         report->length = cpu_to_be16(read_length);
 519         report->target_address_length = addr_length;
 520         memcpy(report->target_address, addr, addr_length);
 521         return addr_length + 5;
 522 }
 523
 524 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 525                            int num)
 526 {
 527         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 528         struct hid_device *hdev = dev->hdev;
 529         u8 buf[64];
 530         ssize_t count;
 531         ssize_t read_length = 0;
 532         u8 *read_buf = NULL;
 533         unsigned int retries;
 534         int ret;
 535
 536         hid_dbg(hdev, "I2C %d messages\n", num);
 537
 538         if (num == 1) {
 539                 if (msgs->flags & I2C_M_RD) {
 540                         hid_dbg(hdev, "I2C read %#04x len %d\n",
 541                                 msgs->addr, msgs->len);
 542                         read_length = msgs->len;
 543                         read_buf = msgs->buf;
 544                         count = cp2112_read_req(buf, msgs->addr, msgs->len);
 545                 } else {
 546                         hid_dbg(hdev, "I2C write %#04x len %d\n",
 547                                 msgs->addr, msgs->len);
 548                         count = cp2112_i2c_write_req(buf, msgs->addr,
 549                                                      msgs->buf, msgs->len);
 550                 }
 551                 if (count < 0)
 552                         return count;
 553         } else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
 554                    num == 2 &&
 555                    msgs[0].addr == msgs[1].addr &&
 556                    !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
 557                 hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
 558                         msgs[0].addr, msgs[0].len, msgs[1].len);
 559                 read_length = msgs[1].len;
 560                 read_buf = msgs[1].buf;
 561                 count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
 562                                 msgs[0].buf, msgs[0].len, msgs[1].len);
 563                 if (count < 0)
 564                         return count;
 565         } else {
 566                 hid_err(hdev,
 567                         "Multi-message I2C transactions not supported\n");
 568                 return -EOPNOTSUPP;
 569         }
 570
 571         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 572         if (ret < 0) {
 573                 hid_err(hdev, "power management error: %d\n", ret);
 574                 return ret;
 575         }
 576
 577         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 578         if (ret < 0) {
 579                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 580                 goto power_normal;
 581         }
 582
 583         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 584                 ret = cp2112_xfer_status(dev);
 585                 if (-EBUSY == ret)
 586                         continue;
 587                 if (ret < 0)
 588                         goto power_normal;
 589                 break;
 590         }
 591
 592         if (XFER_STATUS_RETRIES <= retries) {
 593                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 594                 buf[0] = CP2112_CANCEL_TRANSFER;
 595                 buf[1] = 0x01;
 596
 597                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 598                 if (ret < 0)
 599                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 600                                  ret);
 601
 602                 ret = -ETIMEDOUT;
 603                 goto power_normal;
 604         }
 605
 606         for (count = 0; count < read_length;) {
 607                 ret = cp2112_read(dev, read_buf + count, read_length - count);
 608                 if (ret < 0)
 609                         goto power_normal;
 610                 if (ret == 0) {
 611                         hid_err(hdev, "read returned 0\n");
 612                         ret = -EIO;
 613                         goto power_normal;
 614                 }
 615                 count += ret;
 616                 if (count > read_length) {
 617                         /*
 618                          * The hardware returned too much data.
 619                          * This is mostly harmless because cp2112_read()
 620                          * has a limit check so didn't overrun our
 621                          * buffer.  Nevertheless, we return an error
 622                          * because something is seriously wrong and
 623                          * it shouldn't go unnoticed.
 624                          */
 625                         hid_err(hdev, "long read: %d > %zd\n",
 626                                 ret, read_length - count + ret);
 627                         ret = -EIO;
 628                         goto power_normal;
 629                 }
 630         }
 631
 632         /* return the number of transferred messages */
 633         ret = num;
 634
 635 power_normal:
 636         hid_hw_power(hdev, PM_HINT_NORMAL);
 637         hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
 638         return ret;
 639 }
 640
 641 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 642                        unsigned short flags, char read_write, u8 command,
 643                        int size, union i2c_smbus_data *data)
 644 {
 645         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 646         struct hid_device *hdev = dev->hdev;
 647         u8 buf[64];
 648         __le16 word;
 649         ssize_t count;
 650         size_t read_length = 0;
 651         unsigned int retries;
 652         int ret;
 653
 654         hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
 655                 read_write == I2C_SMBUS_WRITE ? "write" : "read",
 656                 addr, flags, command, size);
 657
 658         switch (size) {
 659         case I2C_SMBUS_BYTE:
 660                 read_length = 1;
 661
 662                 if (I2C_SMBUS_READ == read_write)
 663                         count = cp2112_read_req(buf, addr, read_length);
 664                 else
 665                         count = cp2112_write_req(buf, addr, command, NULL,
 666                                                  0);
 667                 break;
 668         case I2C_SMBUS_BYTE_DATA:
 669                 read_length = 1;
 670
 671                 if (I2C_SMBUS_READ == read_write)
 672                         count = cp2112_write_read_req(buf, addr, read_length,
 673                                                       command, NULL, 0);
 674                 else
 675                         count = cp2112_write_req(buf, addr, command,
 676                                                  &data->byte, 1);
 677                 break;
 678         case I2C_SMBUS_WORD_DATA:
 679                 read_length = 2;
 680                 word = cpu_to_le16(data->word);
 681
 682                 if (I2C_SMBUS_READ == read_write)
 683                         count = cp2112_write_read_req(buf, addr, read_length,
 684                                                       command, NULL, 0);
 685                 else
 686                         count = cp2112_write_req(buf, addr, command,
 687                                                  (u8 *)&word, 2);
 688                 break;
 689         case I2C_SMBUS_PROC_CALL:
 690                 size = I2C_SMBUS_WORD_DATA;
 691                 read_write = I2C_SMBUS_READ;
 692                 read_length = 2;
 693                 word = cpu_to_le16(data->word);
 694
 695                 count = cp2112_write_read_req(buf, addr, read_length, command,
 696                                               (u8 *)&word, 2);
 697                 break;
 698         case I2C_SMBUS_I2C_BLOCK_DATA:
 699                 if (read_write == I2C_SMBUS_READ) {
 700                         read_length = data->block[0];
 701                         count = cp2112_write_read_req(buf, addr, read_length,
 702                                                       command, NULL, 0);
 703                 } else {
 704                         count = cp2112_write_req(buf, addr, command,
 705                                                  data->block + 1,
 706                                                  data->block[0]);
 707                 }
 708                 break;
 709         case I2C_SMBUS_BLOCK_DATA:
 710                 if (I2C_SMBUS_READ == read_write) {
 711                         count = cp2112_write_read_req(buf, addr,
 712                                                       I2C_SMBUS_BLOCK_MAX,
 713                                                       command, NULL, 0);
 714                 } else {
 715                         count = cp2112_write_req(buf, addr, command,
 716                                                  data->block,
 717                                                  data->block[0] + 1);
 718                 }
 719                 break;
 720         case I2C_SMBUS_BLOCK_PROC_CALL:
 721                 size = I2C_SMBUS_BLOCK_DATA;
 722                 read_write = I2C_SMBUS_READ;
 723
 724                 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
 725                                               command, data->block,
 726                                               data->block[0] + 1);
 727                 break;
 728         default:
 729                 hid_warn(hdev, "Unsupported transaction %d\n", size);
 730                 return -EOPNOTSUPP;
 731         }
 732
 733         if (count < 0)
 734                 return count;
 735
 736         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 737         if (ret < 0) {
 738                 hid_err(hdev, "power management error: %d\n", ret);
 739                 return ret;
 740         }
 741
 742         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 743         if (ret < 0) {
 744                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 745                 goto power_normal;
 746         }
 747
 748         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 749                 ret = cp2112_xfer_status(dev);
 750                 if (-EBUSY == ret)
 751                         continue;
 752                 if (ret < 0)
 753                         goto power_normal;
 754                 break;
 755         }
 756
 757         if (XFER_STATUS_RETRIES <= retries) {
 758                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 759                 buf[0] = CP2112_CANCEL_TRANSFER;
 760                 buf[1] = 0x01;
 761
 762                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 763                 if (ret < 0)
 764                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 765                                  ret);
 766
 767                 ret = -ETIMEDOUT;
 768                 goto power_normal;
 769         }
 770
 771         if (I2C_SMBUS_WRITE == read_write) {
 772                 ret = 0;
 773                 goto power_normal;
 774         }
 775
 776         if (I2C_SMBUS_BLOCK_DATA == size)
 777                 read_length = ret;
 778
 779         ret = cp2112_read(dev, buf, read_length);
 780         if (ret < 0)
 781                 goto power_normal;
 782         if (ret != read_length) {
 783                 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
 784                 ret = -EIO;
 785                 goto power_normal;
 786         }
 787
 788         switch (size) {
 789         case I2C_SMBUS_BYTE:
 790         case I2C_SMBUS_BYTE_DATA:
 791                 data->byte = buf[0];
 792                 break;
 793         case I2C_SMBUS_WORD_DATA:
 794                 data->word = le16_to_cpup((__le16 *)buf);
 795                 break;
 796         case I2C_SMBUS_I2C_BLOCK_DATA:
 797                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 798                         ret = -EINVAL;
 799                         goto power_normal;
 800                 }
 801
 802                 memcpy(data->block + 1, buf, read_length);
 803                 break;
 804         case I2C_SMBUS_BLOCK_DATA:
 805                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 806                         ret = -EPROTO;
 807                         goto power_normal;
 808                 }
 809
 810                 memcpy(data->block, buf, read_length);
 811                 break;
 812         }
 813
 814         ret = 0;
 815 power_normal:
 816         hid_hw_power(hdev, PM_HINT_NORMAL);
 817         hid_dbg(hdev, "transfer finished: %d\n", ret);
 818         return ret;
 819 }
 820
 821 static u32 cp2112_functionality(struct i2c_adapter *adap)
 822 {
 823         return I2C_FUNC_I2C |
 824                 I2C_FUNC_SMBUS_BYTE |
 825                 I2C_FUNC_SMBUS_BYTE_DATA |
 826                 I2C_FUNC_SMBUS_WORD_DATA |
 827                 I2C_FUNC_SMBUS_BLOCK_DATA |
 828                 I2C_FUNC_SMBUS_I2C_BLOCK |
 829                 I2C_FUNC_SMBUS_PROC_CALL |
 830                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 831 }
 832
 833 static const struct i2c_algorithm smbus_algorithm = {
 834         .master_xfer    = cp2112_i2c_xfer,
 835         .smbus_xfer     = cp2112_xfer,
 836         .functionality  = cp2112_functionality,
 837 };
 838
 839 static int cp2112_get_usb_config(struct hid_device *hdev,
 840                                  struct cp2112_usb_config_report *cfg)
 841 {
 842         int ret;
 843
 844         ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
 845                              HID_FEATURE_REPORT);
 846         if (ret != sizeof(*cfg)) {
 847                 hid_err(hdev, "error reading usb config: %d\n", ret);
 848                 if (ret < 0)
 849                         return ret;
 850                 return -EIO;
 851         }
 852
 853         return 0;
 854 }
 855
 856 static int cp2112_set_usb_config(struct hid_device *hdev,
 857                                  struct cp2112_usb_config_report *cfg)
 858 {
 859         int ret;
 860
 861         BUG_ON(cfg->report != CP2112_USB_CONFIG);
 862
 863         ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
 864                                 HID_FEATURE_REPORT);
 865         if (ret != sizeof(*cfg)) {
 866                 hid_err(hdev, "error writing usb config: %d\n", ret);
 867                 if (ret < 0)
 868                         return ret;
 869                 return -EIO;
 870         }
 871
 872         return 0;
 873 }
 874
 875 static void chmod_sysfs_attrs(struct hid_device *hdev);
 876
 877 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
 878 static ssize_t name##_store(struct device *kdev, \
 879                             struct device_attribute *attr, const char *buf, \
 880                             size_t count) \
 881 { \
 882         struct hid_device *hdev = to_hid_device(kdev); \
 883         struct cp2112_usb_config_report cfg; \
 884         int ret = cp2112_get_usb_config(hdev, &cfg); \
 885         if (ret) \
 886                 return ret; \
 887         store; \
 888         ret = cp2112_set_usb_config(hdev, &cfg); \
 889         if (ret) \
 890                 return ret; \
 891         chmod_sysfs_attrs(hdev); \
 892         return count; \
 893 } \
 894 static ssize_t name##_show(struct device *kdev, \
 895                            struct device_attribute *attr, char *buf) \
 896 { \
 897         struct hid_device *hdev = to_hid_device(kdev); \
 898         struct cp2112_usb_config_report cfg; \
 899         int ret = cp2112_get_usb_config(hdev, &cfg); \
 900         if (ret) \
 901                 return ret; \
 902         return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
 903 } \
 904 static DEVICE_ATTR_RW(name);
 905
 906 CP2112_CONFIG_ATTR(vendor_id, ({
 907         u16 vid;
 908
 909         if (sscanf(buf, "%hi", &vid) != 1)
 910                 return -EINVAL;
 911
 912         cfg.vid = cpu_to_le16(vid);
 913         cfg.mask = 0x01;
 914 }), "0x%04x\n", le16_to_cpu(cfg.vid));
 915
 916 CP2112_CONFIG_ATTR(product_id, ({
 917         u16 pid;
 918
 919         if (sscanf(buf, "%hi", &pid) != 1)
 920                 return -EINVAL;
 921
 922         cfg.pid = cpu_to_le16(pid);
 923         cfg.mask = 0x02;
 924 }), "0x%04x\n", le16_to_cpu(cfg.pid));
 925
 926 CP2112_CONFIG_ATTR(max_power, ({
 927         int mA;
 928
 929         if (sscanf(buf, "%i", &mA) != 1)
 930                 return -EINVAL;
 931
 932         cfg.max_power = (mA + 1) / 2;
 933         cfg.mask = 0x04;
 934 }), "%u mA\n", cfg.max_power * 2);
 935
 936 CP2112_CONFIG_ATTR(power_mode, ({
 937         if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
 938                 return -EINVAL;
 939
 940         cfg.mask = 0x08;
 941 }), "%u\n", cfg.power_mode);
 942
 943 CP2112_CONFIG_ATTR(release_version, ({
 944         if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
 945             != 2)
 946                 return -EINVAL;
 947
 948         cfg.mask = 0x10;
 949 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
 950
 951 #undef CP2112_CONFIG_ATTR
 952
 953 struct cp2112_pstring_attribute {
 954         struct device_attribute attr;
 955         unsigned char report;
 956 };
 957
 958 static ssize_t pstr_store(struct device *kdev,
 959                           struct device_attribute *kattr, const char *buf,
 960                           size_t count)
 961 {
 962         struct hid_device *hdev = to_hid_device(kdev);
 963         struct cp2112_pstring_attribute *attr =
 964                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 965         struct cp2112_string_report report;
 966         int ret;
 967
 968         memset(&report, 0, sizeof(report));
 969
 970         ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 971                               report.string, ARRAY_SIZE(report.string));
 972         report.report = attr->report;
 973         report.length = ret * sizeof(report.string[0]) + 2;
 974         report.type = USB_DT_STRING;
 975
 976         ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
 977                                 HID_FEATURE_REPORT);
 978         if (ret != report.length + 1) {
 979                 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
 980                         ret);
 981                 if (ret < 0)
 982                         return ret;
 983                 return -EIO;
 984         }
 985
 986         chmod_sysfs_attrs(hdev);
 987         return count;
 988 }
 989
 990 static ssize_t pstr_show(struct device *kdev,
 991                          struct device_attribute *kattr, char *buf)
 992 {
 993         struct hid_device *hdev = to_hid_device(kdev);
 994         struct cp2112_pstring_attribute *attr =
 995                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 996         struct cp2112_string_report report;
 997         u8 length;
 998         int ret;
 999
1000         ret = cp2112_hid_get(hdev, attr->report, &report.report,
1001                              sizeof(report) - 1, HID_FEATURE_REPORT);
1002         if (ret < 3) {
1003                 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
1004                         ret);
1005                 if (ret < 0)
1006                         return ret;
1007                 return -EIO;
1008         }
1009
1010         if (report.length < 2) {
1011                 hid_err(hdev, "invalid %s string length: %d\n",
1012                         kattr->attr.name, report.length);
1013                 return -EIO;
1014         }
1015
1016         length = report.length > ret - 1 ? ret - 1 : report.length;
1017         length = (length - 2) / sizeof(report.string[0]);
1018         ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1019                               PAGE_SIZE - 1);
1020         buf[ret++] = '\n';
1021         return ret;
1022 }
1023
1024 #define CP2112_PSTR_ATTR(name, _report) \
1025 static struct cp2112_pstring_attribute dev_attr_##name = { \
1026         .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
1027         .report = _report, \
1028 };
1029
1030 CP2112_PSTR_ATTR(manufacturer,  CP2112_MANUFACTURER_STRING);
1031 CP2112_PSTR_ATTR(product,       CP2112_PRODUCT_STRING);
1032 CP2112_PSTR_ATTR(serial,        CP2112_SERIAL_STRING);
1033
1034 #undef CP2112_PSTR_ATTR
1035
1036 static const struct attribute_group cp2112_attr_group = {
1037         .attrs = (struct attribute *[]){
1038                 &dev_attr_vendor_id.attr,
1039                 &dev_attr_product_id.attr,
1040                 &dev_attr_max_power.attr,
1041                 &dev_attr_power_mode.attr,
1042                 &dev_attr_release_version.attr,
1043                 &dev_attr_manufacturer.attr.attr,
1044                 &dev_attr_product.attr.attr,
1045                 &dev_attr_serial.attr.attr,
1046                 NULL
1047         }
1048 };
1049
1050 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1051  * PROM have already been programmed. We do not depend on this preventing
1052  * writing to these attributes since the CP2112 will simply ignore writes to
1053  * already-programmed fields. This is why there is no sense in fixing this
1054  * racy behaviour.
1055  */
1056 static void chmod_sysfs_attrs(struct hid_device *hdev)
1057 {
1058         struct attribute **attr;
1059         u8 buf[2];
1060         int ret;
1061
1062         ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1063                              HID_FEATURE_REPORT);
1064         if (ret != sizeof(buf)) {
1065                 hid_err(hdev, "error reading lock byte: %d\n", ret);
1066                 return;
1067         }
1068
1069         for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1070                 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
1071                 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1072                 if (ret < 0)
1073                         hid_err(hdev, "error chmoding sysfs file %s\n",
1074                                 (*attr)->name);
1075                 buf[1] >>= 1;
1076         }
1077 }
1078
1079 static void cp2112_gpio_irq_ack(struct irq_data *d)
1080 {
1081 }
1082
1083 static void cp2112_gpio_irq_mask(struct irq_data *d)
1084 {
1085         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1086         struct cp2112_device *dev = gpiochip_get_data(gc);
1087
1088         __clear_bit(d->hwirq, &dev->irq_mask);
1089 }
1090
1091 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1092 {
1093         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1094         struct cp2112_device *dev = gpiochip_get_data(gc);
1095
1096         __set_bit(d->hwirq, &dev->irq_mask);
1097 }
1098
1099 static void cp2112_gpio_poll_callback(struct work_struct *work)
1100 {
1101         struct cp2112_device *dev = container_of(work, struct cp2112_device,
1102                                                  gpio_poll_worker.work);
1103         struct irq_data *d;
1104         u8 gpio_mask;
1105         u8 virqs = (u8)dev->irq_mask;
1106         u32 irq_type;
1107         int irq, virq, ret;
1108
1109         ret = cp2112_gpio_get_all(&dev->gc);
1110         if (ret == -ENODEV) /* the hardware has been disconnected */
1111                 return;
1112         if (ret < 0)
1113                 goto exit;
1114
1115         gpio_mask = ret;
1116
1117         while (virqs) {
1118                 virq = ffs(virqs) - 1;
1119                 virqs &= ~BIT(virq);
1120
1121                 if (!dev->gc.to_irq)
1122                         break;
1123
1124                 irq = dev->gc.to_irq(&dev->gc, virq);
1125
1126                 d = irq_get_irq_data(irq);
1127                 if (!d)
1128                         continue;
1129
1130                 irq_type = irqd_get_trigger_type(d);
1131
1132                 if (gpio_mask & BIT(virq)) {
1133                         /* Level High */
1134
1135                         if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1136                                 handle_nested_irq(irq);
1137
1138                         if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1139                             !(dev->gpio_prev_state & BIT(virq)))
1140                                 handle_nested_irq(irq);
1141                 } else {
1142                         /* Level Low */
1143
1144                         if (irq_type & IRQ_TYPE_LEVEL_LOW)
1145                                 handle_nested_irq(irq);
1146
1147                         if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1148                             (dev->gpio_prev_state & BIT(virq)))
1149                                 handle_nested_irq(irq);
1150                 }
1151         }
1152
1153         dev->gpio_prev_state = gpio_mask;
1154
1155 exit:
1156         if (dev->gpio_poll)
1157                 schedule_delayed_work(&dev->gpio_poll_worker, 10);
1158 }
1159
1160
1161 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1162 {
1163         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1164         struct cp2112_device *dev = gpiochip_get_data(gc);
1165
1166         INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1167
1168         if (!dev->gpio_poll) {
1169                 dev->gpio_poll = true;
1170                 schedule_delayed_work(&dev->gpio_poll_worker, 0);
1171         }
1172
1173         cp2112_gpio_irq_unmask(d);
1174         return 0;
1175 }
1176
1177 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1178 {
1179         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1180         struct cp2112_device *dev = gpiochip_get_data(gc);
1181
1182         cancel_delayed_work_sync(&dev->gpio_poll_worker);
1183 }
1184
1185 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1186 {
1187         return 0;
1188 }
1189
1190 static struct irq_chip cp2112_gpio_irqchip = {
1191         .name = "cp2112-gpio",
1192         .irq_startup = cp2112_gpio_irq_startup,
1193         .irq_shutdown = cp2112_gpio_irq_shutdown,
1194         .irq_ack = cp2112_gpio_irq_ack,
1195         .irq_mask = cp2112_gpio_irq_mask,
1196         .irq_unmask = cp2112_gpio_irq_unmask,
1197         .irq_set_type = cp2112_gpio_irq_type,
1198 };
1199
1200 static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
1201                                               int pin)
1202 {
1203         int ret;
1204
1205         if (dev->desc[pin])
1206                 return -EINVAL;
1207
1208         dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
1209                                                    "HID/I2C:Event");
1210         if (IS_ERR(dev->desc[pin])) {
1211                 dev_err(dev->gc.parent, "Failed to request GPIO\n");
1212                 return PTR_ERR(dev->desc[pin]);
1213         }
1214
1215         ret = cp2112_gpio_direction_input(&dev->gc, pin);
1216         if (ret < 0) {
1217                 dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n");
1218                 goto err_desc;
1219         }
1220
1221         ret = gpiochip_lock_as_irq(&dev->gc, pin);
1222         if (ret) {
1223                 dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
1224                 goto err_desc;
1225         }
1226
1227         ret = gpiod_to_irq(dev->desc[pin]);
1228         if (ret < 0) {
1229                 dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
1230                 goto err_lock;
1231         }
1232
1233         return ret;
1234
1235 err_lock:
1236         gpiochip_unlock_as_irq(&dev->gc, pin);
1237 err_desc:
1238         gpiochip_free_own_desc(dev->desc[pin]);
1239         dev->desc[pin] = NULL;
1240         return ret;
1241 }
1242
1243 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1244 {
1245         struct cp2112_device *dev;
1246         u8 buf[3];
1247         struct cp2112_smbus_config_report config;
1248         int ret;
1249
1250         dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1251         if (!dev)
1252                 return -ENOMEM;
1253
1254         dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1255                                           GFP_KERNEL);
1256         if (!dev->in_out_buffer)
1257                 return -ENOMEM;
1258
1259         mutex_init(&dev->lock);
1260
1261         ret = hid_parse(hdev);
1262         if (ret) {
1263                 hid_err(hdev, "parse failed\n");
1264                 return ret;
1265         }
1266
1267         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1268         if (ret) {
1269                 hid_err(hdev, "hw start failed\n");
1270                 return ret;
1271         }
1272
1273         ret = hid_hw_open(hdev);
1274         if (ret) {
1275                 hid_err(hdev, "hw open failed\n");
1276                 goto err_hid_stop;
1277         }
1278
1279         ret = hid_hw_power(hdev, PM_HINT_FULLON);
1280         if (ret < 0) {
1281                 hid_err(hdev, "power management error: %d\n", ret);
1282                 goto err_hid_close;
1283         }
1284
1285         ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1286                              HID_FEATURE_REPORT);
1287         if (ret != sizeof(buf)) {
1288                 hid_err(hdev, "error requesting version\n");
1289                 if (ret >= 0)
1290                         ret = -EIO;
1291                 goto err_power_normal;
1292         }
1293
1294         hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1295                  buf[1], buf[2]);
1296
1297         ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1298                              sizeof(config), HID_FEATURE_REPORT);
1299         if (ret != sizeof(config)) {
1300                 hid_err(hdev, "error requesting SMBus config\n");
1301                 if (ret >= 0)
1302                         ret = -EIO;
1303                 goto err_power_normal;
1304         }
1305
1306         config.retry_time = cpu_to_be16(1);
1307
1308         ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1309                                 HID_FEATURE_REPORT);
1310         if (ret != sizeof(config)) {
1311                 hid_err(hdev, "error setting SMBus config\n");
1312                 if (ret >= 0)
1313                         ret = -EIO;
1314                 goto err_power_normal;
1315         }
1316
1317         hid_set_drvdata(hdev, (void *)dev);
1318         dev->hdev               = hdev;
1319         dev->adap.owner         = THIS_MODULE;
1320         dev->adap.class         = I2C_CLASS_HWMON;
1321         dev->adap.algo          = &smbus_algorithm;
1322         dev->adap.algo_data     = dev;
1323         dev->adap.dev.parent    = &hdev->dev;
1324         snprintf(dev->adap.name, sizeof(dev->adap.name),
1325                  "CP2112 SMBus Bridge on hidraw%d",
1326                  ((struct hidraw *)hdev->hidraw)->minor);
1327         dev->hwversion = buf[2];
1328         init_waitqueue_head(&dev->wait);
1329
1330         hid_device_io_start(hdev);
1331         ret = i2c_add_adapter(&dev->adap);
1332         hid_device_io_stop(hdev);
1333
1334         if (ret) {
1335                 hid_err(hdev, "error registering i2c adapter\n");
1336                 goto err_power_normal;
1337         }
1338
1339         hid_dbg(hdev, "adapter registered\n");
1340
1341         dev->gc.label                   = "cp2112_gpio";
1342         dev->gc.direction_input         = cp2112_gpio_direction_input;
1343         dev->gc.direction_output        = cp2112_gpio_direction_output;
1344         dev->gc.set                     = cp2112_gpio_set;
1345         dev->gc.get                     = cp2112_gpio_get;
1346         dev->gc.base                    = -1;
1347         dev->gc.ngpio                   = 8;
1348         dev->gc.can_sleep               = 1;
1349         dev->gc.parent                  = &hdev->dev;
1350
1351         ret = gpiochip_add_data(&dev->gc, dev);
1352         if (ret < 0) {
1353                 hid_err(hdev, "error registering gpio chip\n");
1354                 goto err_free_i2c;
1355         }
1356
1357         ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1358         if (ret < 0) {
1359                 hid_err(hdev, "error creating sysfs attrs\n");
1360                 goto err_gpiochip_remove;
1361         }
1362
1363         chmod_sysfs_attrs(hdev);
1364         hid_hw_power(hdev, PM_HINT_NORMAL);
1365
1366         ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
1367                                    handle_simple_irq, IRQ_TYPE_NONE);
1368         if (ret) {
1369                 dev_err(dev->gc.parent, "failed to add IRQ chip\n");
1370                 goto err_sysfs_remove;
1371         }
1372
1373         return ret;
1374
1375 err_sysfs_remove:
1376         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1377 err_gpiochip_remove:
1378         gpiochip_remove(&dev->gc);
1379 err_free_i2c:
1380         i2c_del_adapter(&dev->adap);
1381 err_power_normal:
1382         hid_hw_power(hdev, PM_HINT_NORMAL);
1383 err_hid_close:
1384         hid_hw_close(hdev);
1385 err_hid_stop:
1386         hid_hw_stop(hdev);
1387         return ret;
1388 }
1389
1390 static void cp2112_remove(struct hid_device *hdev)
1391 {
1392         struct cp2112_device *dev = hid_get_drvdata(hdev);
1393         int i;
1394
1395         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1396         i2c_del_adapter(&dev->adap);
1397
1398         if (dev->gpio_poll) {
1399                 dev->gpio_poll = false;
1400                 cancel_delayed_work_sync(&dev->gpio_poll_worker);
1401         }
1402
1403         for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
1404                 gpiochip_unlock_as_irq(&dev->gc, i);
1405                 gpiochip_free_own_desc(dev->desc[i]);
1406         }
1407
1408         gpiochip_remove(&dev->gc);
1409         /* i2c_del_adapter has finished removing all i2c devices from our
1410          * adapter. Well behaved devices should no longer call our cp2112_xfer
1411          * and should have waited for any pending calls to finish. It has also
1412          * waited for device_unregister(&adap->dev) to complete. Therefore we
1413          * can safely free our struct cp2112_device.
1414          */
1415         hid_hw_close(hdev);
1416         hid_hw_stop(hdev);
1417 }
1418
1419 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1420                             u8 *data, int size)
1421 {
1422         struct cp2112_device *dev = hid_get_drvdata(hdev);
1423         struct cp2112_xfer_status_report *xfer = (void *)data;
1424
1425         switch (data[0]) {
1426         case CP2112_TRANSFER_STATUS_RESPONSE:
1427                 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1428                         xfer->status0, xfer->status1,
1429                         be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1430
1431                 switch (xfer->status0) {
1432                 case STATUS0_IDLE:
1433                         dev->xfer_status = -EAGAIN;
1434                         break;
1435                 case STATUS0_BUSY:
1436                         dev->xfer_status = -EBUSY;
1437                         break;
1438                 case STATUS0_COMPLETE:
1439                         dev->xfer_status = be16_to_cpu(xfer->length);
1440                         break;
1441                 case STATUS0_ERROR:
1442                         switch (xfer->status1) {
1443                         case STATUS1_TIMEOUT_NACK:
1444                         case STATUS1_TIMEOUT_BUS:
1445                                 dev->xfer_status = -ETIMEDOUT;
1446                                 break;
1447                         default:
1448                                 dev->xfer_status = -EIO;
1449                                 break;
1450                         }
1451                         break;
1452                 default:
1453                         dev->xfer_status = -EINVAL;
1454                         break;
1455                 }
1456
1457                 atomic_set(&dev->xfer_avail, 1);
1458                 break;
1459         case CP2112_DATA_READ_RESPONSE:
1460                 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1461
1462                 dev->read_length = data[2];
1463                 if (dev->read_length > sizeof(dev->read_data))
1464                         dev->read_length = sizeof(dev->read_data);
1465
1466                 memcpy(dev->read_data, &data[3], dev->read_length);
1467                 atomic_set(&dev->read_avail, 1);
1468                 break;
1469         default:
1470                 hid_err(hdev, "unknown report\n");
1471
1472                 return 0;
1473         }
1474
1475         wake_up_interruptible(&dev->wait);
1476         return 1;
1477 }
1478
1479 static struct hid_driver cp2112_driver = {
1480         .name           = "cp2112",
1481         .id_table       = cp2112_devices,
1482         .probe          = cp2112_probe,
1483         .remove         = cp2112_remove,
1484         .raw_event      = cp2112_raw_event,
1485 };
1486
1487 module_hid_driver(cp2112_driver);
1488 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1489 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1490 MODULE_LICENSE("GPL");
1491