drivers/hid/hid-cp2112.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
   4  * Copyright (c) 2013,2014 Uplogix, Inc.
   5  * David Barksdale <dbarksdale@uplogix.com>
   6  */
   7
   8 /*
   9  * The Silicon Labs CP2112 chip is a USB HID device which provides an
  10  * SMBus controller for talking to slave devices and 8 GPIO pins. The
  11  * host communicates with the CP2112 via raw HID reports.
  12  *
  13  * Data Sheet:
  14  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
  15  * Programming Interface Specification:
  16  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
  17  */
  18
  19 #include <linux/gpio/consumer.h>
  20 #include <linux/gpio/machine.h>
  21 #include <linux/gpio/driver.h>
  22 #include <linux/hid.h>
  23 #include <linux/hidraw.h>
  24 #include <linux/i2c.h>
  25 #include <linux/module.h>
  26 #include <linux/nls.h>
  27 #include <linux/usb/ch9.h>
  28 #include "hid-ids.h"
  29
  30 #define CP2112_REPORT_MAX_LENGTH                64
  31 #define CP2112_GPIO_CONFIG_LENGTH               5
  32 #define CP2112_GPIO_GET_LENGTH                  2
  33 #define CP2112_GPIO_SET_LENGTH                  3
  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         u8 *in_out_buffer;
 165         struct mutex lock;
 166
 167         struct gpio_desc *desc[8];
 168         bool gpio_poll;
 169         struct delayed_work gpio_poll_worker;
 170         unsigned long irq_mask;
 171         u8 gpio_prev_state;
 172 };
 173
 174 static int gpio_push_pull = 0xFF;
 175 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
 176 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
 177
 178 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 179 {
 180         struct cp2112_device *dev = gpiochip_get_data(chip);
 181         struct hid_device *hdev = dev->hdev;
 182         u8 *buf = dev->in_out_buffer;
 183         int ret;
 184
 185         mutex_lock(&dev->lock);
 186
 187         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 188                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 189                                  HID_REQ_GET_REPORT);
 190         if (ret != CP2112_GPIO_CONFIG_LENGTH) {
 191                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 192                 if (ret >= 0)
 193                         ret = -EIO;
 194                 goto exit;
 195         }
 196
 197         buf[1] &= ~(1 << offset);
 198         buf[2] = gpio_push_pull;
 199
 200         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 201                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 202                                  HID_REQ_SET_REPORT);
 203         if (ret != CP2112_GPIO_CONFIG_LENGTH) {
 204                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 205                 if (ret >= 0)
 206                         ret = -EIO;
 207                 goto exit;
 208         }
 209
 210         ret = 0;
 211
 212 exit:
 213         mutex_unlock(&dev->lock);
 214         return ret;
 215 }
 216
 217 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 218 {
 219         struct cp2112_device *dev = gpiochip_get_data(chip);
 220         struct hid_device *hdev = dev->hdev;
 221         u8 *buf = dev->in_out_buffer;
 222         int ret;
 223
 224         mutex_lock(&dev->lock);
 225
 226         buf[0] = CP2112_GPIO_SET;
 227         buf[1] = value ? 0xff : 0;
 228         buf[2] = 1 << offset;
 229
 230         ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
 231                                  CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
 232                                  HID_REQ_SET_REPORT);
 233         if (ret < 0)
 234                 hid_err(hdev, "error setting GPIO values: %d\n", ret);
 235
 236         mutex_unlock(&dev->lock);
 237 }
 238
 239 static int cp2112_gpio_get_all(struct gpio_chip *chip)
 240 {
 241         struct cp2112_device *dev = gpiochip_get_data(chip);
 242         struct hid_device *hdev = dev->hdev;
 243         u8 *buf = dev->in_out_buffer;
 244         int ret;
 245
 246         mutex_lock(&dev->lock);
 247
 248         ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
 249                                  CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
 250                                  HID_REQ_GET_REPORT);
 251         if (ret != CP2112_GPIO_GET_LENGTH) {
 252                 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
 253                 ret = ret < 0 ? ret : -EIO;
 254                 goto exit;
 255         }
 256
 257         ret = buf[1];
 258
 259 exit:
 260         mutex_unlock(&dev->lock);
 261
 262         return ret;
 263 }
 264
 265 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
 266 {
 267         int ret;
 268
 269         ret = cp2112_gpio_get_all(chip);
 270         if (ret < 0)
 271                 return ret;
 272
 273         return (ret >> offset) & 1;
 274 }
 275
 276 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
 277                                         unsigned offset, int value)
 278 {
 279         struct cp2112_device *dev = gpiochip_get_data(chip);
 280         struct hid_device *hdev = dev->hdev;
 281         u8 *buf = dev->in_out_buffer;
 282         int ret;
 283
 284         mutex_lock(&dev->lock);
 285
 286         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 287                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 288                                  HID_REQ_GET_REPORT);
 289         if (ret != CP2112_GPIO_CONFIG_LENGTH) {
 290                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 291                 goto fail;
 292         }
 293
 294         buf[1] |= 1 << offset;
 295         buf[2] = gpio_push_pull;
 296
 297         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 298                                  CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
 299                                  HID_REQ_SET_REPORT);
 300         if (ret < 0) {
 301                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 302                 goto fail;
 303         }
 304
 305         mutex_unlock(&dev->lock);
 306
 307         /*
 308          * Set gpio value when output direction is already set,
 309          * as specified in AN495, Rev. 0.2, cpt. 4.4
 310          */
 311         cp2112_gpio_set(chip, offset, value);
 312
 313         return 0;
 314
 315 fail:
 316         mutex_unlock(&dev->lock);
 317         return ret < 0 ? ret : -EIO;
 318 }
 319
 320 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
 321                           u8 *data, size_t count, unsigned char report_type)
 322 {
 323         u8 *buf;
 324         int ret;
 325
 326         buf = kmalloc(count, GFP_KERNEL);
 327         if (!buf)
 328                 return -ENOMEM;
 329
 330         ret = hid_hw_raw_request(hdev, report_number, buf, count,
 331                                        report_type, HID_REQ_GET_REPORT);
 332         memcpy(data, buf, count);
 333         kfree(buf);
 334         return ret;
 335 }
 336
 337 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
 338                              unsigned char report_type)
 339 {
 340         u8 *buf;
 341         int ret;
 342
 343         buf = kmemdup(data, count, GFP_KERNEL);
 344         if (!buf)
 345                 return -ENOMEM;
 346
 347         if (report_type == HID_OUTPUT_REPORT)
 348                 ret = hid_hw_output_report(hdev, buf, count);
 349         else
 350                 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
 351                                 HID_REQ_SET_REPORT);
 352
 353         kfree(buf);
 354         return ret;
 355 }
 356
 357 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
 358 {
 359         int ret = 0;
 360
 361         /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
 362          * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
 363          * come in cp2112_raw_event or timeout. There will only be one of these
 364          * in flight at any one time. The timeout is extremely large and is a
 365          * last resort if the CP2112 has died. If we do timeout we don't expect
 366          * to receive the response which would cause data races, it's not like
 367          * we can do anything about it anyway.
 368          */
 369         ret = wait_event_interruptible_timeout(dev->wait,
 370                 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
 371         if (-ERESTARTSYS == ret)
 372                 return ret;
 373         if (!ret)
 374                 return -ETIMEDOUT;
 375
 376         atomic_set(avail, 0);
 377         return 0;
 378 }
 379
 380 static int cp2112_xfer_status(struct cp2112_device *dev)
 381 {
 382         struct hid_device *hdev = dev->hdev;
 383         u8 buf[2];
 384         int ret;
 385
 386         buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
 387         buf[1] = 0x01;
 388         atomic_set(&dev->xfer_avail, 0);
 389
 390         ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 391         if (ret < 0) {
 392                 hid_warn(hdev, "Error requesting status: %d\n", ret);
 393                 return ret;
 394         }
 395
 396         ret = cp2112_wait(dev, &dev->xfer_avail);
 397         if (ret)
 398                 return ret;
 399
 400         return dev->xfer_status;
 401 }
 402
 403 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 404 {
 405         struct hid_device *hdev = dev->hdev;
 406         struct cp2112_force_read_report report;
 407         int ret;
 408
 409         if (size > sizeof(dev->read_data))
 410                 size = sizeof(dev->read_data);
 411         report.report = CP2112_DATA_READ_FORCE_SEND;
 412         report.length = cpu_to_be16(size);
 413
 414         atomic_set(&dev->read_avail, 0);
 415
 416         ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
 417                                 HID_OUTPUT_REPORT);
 418         if (ret < 0) {
 419                 hid_warn(hdev, "Error requesting data: %d\n", ret);
 420                 return ret;
 421         }
 422
 423         ret = cp2112_wait(dev, &dev->read_avail);
 424         if (ret)
 425                 return ret;
 426
 427         hid_dbg(hdev, "read %d of %zd bytes requested\n",
 428                 dev->read_length, size);
 429
 430         if (size > dev->read_length)
 431                 size = dev->read_length;
 432
 433         memcpy(data, dev->read_data, size);
 434         return dev->read_length;
 435 }
 436
 437 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
 438 {
 439         struct cp2112_read_req_report *report = buf;
 440
 441         if (length < 1 || length > 512)
 442                 return -EINVAL;
 443
 444         report->report = CP2112_DATA_READ_REQUEST;
 445         report->slave_address = slave_address << 1;
 446         report->length = cpu_to_be16(length);
 447         return sizeof(*report);
 448 }
 449
 450 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
 451                                  u8 command, u8 *data, u8 data_length)
 452 {
 453         struct cp2112_write_read_req_report *report = buf;
 454
 455         if (length < 1 || length > 512
 456             || data_length > sizeof(report->target_address) - 1)
 457                 return -EINVAL;
 458
 459         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 460         report->slave_address = slave_address << 1;
 461         report->length = cpu_to_be16(length);
 462         report->target_address_length = data_length + 1;
 463         report->target_address[0] = command;
 464         memcpy(&report->target_address[1], data, data_length);
 465         return data_length + 6;
 466 }
 467
 468 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
 469                             u8 data_length)
 470 {
 471         struct cp2112_write_req_report *report = buf;
 472
 473         if (data_length > sizeof(report->data) - 1)
 474                 return -EINVAL;
 475
 476         report->report = CP2112_DATA_WRITE_REQUEST;
 477         report->slave_address = slave_address << 1;
 478         report->length = data_length + 1;
 479         report->data[0] = command;
 480         memcpy(&report->data[1], data, data_length);
 481         return data_length + 4;
 482 }
 483
 484 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
 485                                 u8 data_length)
 486 {
 487         struct cp2112_write_req_report *report = buf;
 488
 489         if (data_length > sizeof(report->data))
 490                 return -EINVAL;
 491
 492         report->report = CP2112_DATA_WRITE_REQUEST;
 493         report->slave_address = slave_address << 1;
 494         report->length = data_length;
 495         memcpy(report->data, data, data_length);
 496         return data_length + 3;
 497 }
 498
 499 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
 500                                      u8 *addr, int addr_length,
 501                                      int read_length)
 502 {
 503         struct cp2112_write_read_req_report *report = buf;
 504
 505         if (read_length < 1 || read_length > 512 ||
 506             addr_length > sizeof(report->target_address))
 507                 return -EINVAL;
 508
 509         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 510         report->slave_address = slave_address << 1;
 511         report->length = cpu_to_be16(read_length);
 512         report->target_address_length = addr_length;
 513         memcpy(report->target_address, addr, addr_length);
 514         return addr_length + 5;
 515 }
 516
 517 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 518                            int num)
 519 {
 520         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 521         struct hid_device *hdev = dev->hdev;
 522         u8 buf[64];
 523         ssize_t count;
 524         ssize_t read_length = 0;
 525         u8 *read_buf = NULL;
 526         unsigned int retries;
 527         int ret;
 528
 529         hid_dbg(hdev, "I2C %d messages\n", num);
 530
 531         if (num == 1) {
 532                 if (msgs->flags & I2C_M_RD) {
 533                         hid_dbg(hdev, "I2C read %#04x len %d\n",
 534                                 msgs->addr, msgs->len);
 535                         read_length = msgs->len;
 536                         read_buf = msgs->buf;
 537                         count = cp2112_read_req(buf, msgs->addr, msgs->len);
 538                 } else {
 539                         hid_dbg(hdev, "I2C write %#04x len %d\n",
 540                                 msgs->addr, msgs->len);
 541                         count = cp2112_i2c_write_req(buf, msgs->addr,
 542                                                      msgs->buf, msgs->len);
 543                 }
 544                 if (count < 0)
 545                         return count;
 546         } else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
 547                    num == 2 &&
 548                    msgs[0].addr == msgs[1].addr &&
 549                    !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
 550                 hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
 551                         msgs[0].addr, msgs[0].len, msgs[1].len);
 552                 read_length = msgs[1].len;
 553                 read_buf = msgs[1].buf;
 554                 count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
 555                                 msgs[0].buf, msgs[0].len, msgs[1].len);
 556                 if (count < 0)
 557                         return count;
 558         } else {
 559                 hid_err(hdev,
 560                         "Multi-message I2C transactions not supported\n");
 561                 return -EOPNOTSUPP;
 562         }
 563
 564         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 565         if (ret < 0) {
 566                 hid_err(hdev, "power management error: %d\n", ret);
 567                 return ret;
 568         }
 569
 570         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 571         if (ret < 0) {
 572                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 573                 goto power_normal;
 574         }
 575
 576         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 577                 ret = cp2112_xfer_status(dev);
 578                 if (-EBUSY == ret)
 579                         continue;
 580                 if (ret < 0)
 581                         goto power_normal;
 582                 break;
 583         }
 584
 585         if (XFER_STATUS_RETRIES <= retries) {
 586                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 587                 buf[0] = CP2112_CANCEL_TRANSFER;
 588                 buf[1] = 0x01;
 589
 590                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 591                 if (ret < 0)
 592                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 593                                  ret);
 594
 595                 ret = -ETIMEDOUT;
 596                 goto power_normal;
 597         }
 598
 599         for (count = 0; count < read_length;) {
 600                 ret = cp2112_read(dev, read_buf + count, read_length - count);
 601                 if (ret < 0)
 602                         goto power_normal;
 603                 if (ret == 0) {
 604                         hid_err(hdev, "read returned 0\n");
 605                         ret = -EIO;
 606                         goto power_normal;
 607                 }
 608                 count += ret;
 609                 if (count > read_length) {
 610                         /*
 611                          * The hardware returned too much data.
 612                          * This is mostly harmless because cp2112_read()
 613                          * has a limit check so didn't overrun our
 614                          * buffer.  Nevertheless, we return an error
 615                          * because something is seriously wrong and
 616                          * it shouldn't go unnoticed.
 617                          */
 618                         hid_err(hdev, "long read: %d > %zd\n",
 619                                 ret, read_length - count + ret);
 620                         ret = -EIO;
 621                         goto power_normal;
 622                 }
 623         }
 624
 625         /* return the number of transferred messages */
 626         ret = num;
 627
 628 power_normal:
 629         hid_hw_power(hdev, PM_HINT_NORMAL);
 630         hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
 631         return ret;
 632 }
 633
 634 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 635                        unsigned short flags, char read_write, u8 command,
 636                        int size, union i2c_smbus_data *data)
 637 {
 638         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 639         struct hid_device *hdev = dev->hdev;
 640         u8 buf[64];
 641         __le16 word;
 642         ssize_t count;
 643         size_t read_length = 0;
 644         unsigned int retries;
 645         int ret;
 646
 647         hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
 648                 read_write == I2C_SMBUS_WRITE ? "write" : "read",
 649                 addr, flags, command, size);
 650
 651         switch (size) {
 652         case I2C_SMBUS_BYTE:
 653                 read_length = 1;
 654
 655                 if (I2C_SMBUS_READ == read_write)
 656                         count = cp2112_read_req(buf, addr, read_length);
 657                 else
 658                         count = cp2112_write_req(buf, addr, command, NULL,
 659                                                  0);
 660                 break;
 661         case I2C_SMBUS_BYTE_DATA:
 662                 read_length = 1;
 663
 664                 if (I2C_SMBUS_READ == read_write)
 665                         count = cp2112_write_read_req(buf, addr, read_length,
 666                                                       command, NULL, 0);
 667                 else
 668                         count = cp2112_write_req(buf, addr, command,
 669                                                  &data->byte, 1);
 670                 break;
 671         case I2C_SMBUS_WORD_DATA:
 672                 read_length = 2;
 673                 word = cpu_to_le16(data->word);
 674
 675                 if (I2C_SMBUS_READ == read_write)
 676                         count = cp2112_write_read_req(buf, addr, read_length,
 677                                                       command, NULL, 0);
 678                 else
 679                         count = cp2112_write_req(buf, addr, command,
 680                                                  (u8 *)&word, 2);
 681                 break;
 682         case I2C_SMBUS_PROC_CALL:
 683                 size = I2C_SMBUS_WORD_DATA;
 684                 read_write = I2C_SMBUS_READ;
 685                 read_length = 2;
 686                 word = cpu_to_le16(data->word);
 687
 688                 count = cp2112_write_read_req(buf, addr, read_length, command,
 689                                               (u8 *)&word, 2);
 690                 break;
 691         case I2C_SMBUS_I2C_BLOCK_DATA:
 692                 if (read_write == I2C_SMBUS_READ) {
 693                         read_length = data->block[0];
 694                         count = cp2112_write_read_req(buf, addr, read_length,
 695                                                       command, NULL, 0);
 696                 } else {
 697                         count = cp2112_write_req(buf, addr, command,
 698                                                  data->block + 1,
 699                                                  data->block[0]);
 700                 }
 701                 break;
 702         case I2C_SMBUS_BLOCK_DATA:
 703                 if (I2C_SMBUS_READ == read_write) {
 704                         count = cp2112_write_read_req(buf, addr,
 705                                                       I2C_SMBUS_BLOCK_MAX,
 706                                                       command, NULL, 0);
 707                 } else {
 708                         count = cp2112_write_req(buf, addr, command,
 709                                                  data->block,
 710                                                  data->block[0] + 1);
 711                 }
 712                 break;
 713         case I2C_SMBUS_BLOCK_PROC_CALL:
 714                 size = I2C_SMBUS_BLOCK_DATA;
 715                 read_write = I2C_SMBUS_READ;
 716
 717                 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
 718                                               command, data->block,
 719                                               data->block[0] + 1);
 720                 break;
 721         default:
 722                 hid_warn(hdev, "Unsupported transaction %d\n", size);
 723                 return -EOPNOTSUPP;
 724         }
 725
 726         if (count < 0)
 727                 return count;
 728
 729         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 730         if (ret < 0) {
 731                 hid_err(hdev, "power management error: %d\n", ret);
 732                 return ret;
 733         }
 734
 735         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 736         if (ret < 0) {
 737                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 738                 goto power_normal;
 739         }
 740
 741         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 742                 ret = cp2112_xfer_status(dev);
 743                 if (-EBUSY == ret)
 744                         continue;
 745                 if (ret < 0)
 746                         goto power_normal;
 747                 break;
 748         }
 749
 750         if (XFER_STATUS_RETRIES <= retries) {
 751                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 752                 buf[0] = CP2112_CANCEL_TRANSFER;
 753                 buf[1] = 0x01;
 754
 755                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 756                 if (ret < 0)
 757                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 758                                  ret);
 759
 760                 ret = -ETIMEDOUT;
 761                 goto power_normal;
 762         }
 763
 764         if (I2C_SMBUS_WRITE == read_write) {
 765                 ret = 0;
 766                 goto power_normal;
 767         }
 768
 769         if (I2C_SMBUS_BLOCK_DATA == size)
 770                 read_length = ret;
 771
 772         ret = cp2112_read(dev, buf, read_length);
 773         if (ret < 0)
 774                 goto power_normal;
 775         if (ret != read_length) {
 776                 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
 777                 ret = -EIO;
 778                 goto power_normal;
 779         }
 780
 781         switch (size) {
 782         case I2C_SMBUS_BYTE:
 783         case I2C_SMBUS_BYTE_DATA:
 784                 data->byte = buf[0];
 785                 break;
 786         case I2C_SMBUS_WORD_DATA:
 787                 data->word = le16_to_cpup((__le16 *)buf);
 788                 break;
 789         case I2C_SMBUS_I2C_BLOCK_DATA:
 790                 memcpy(data->block + 1, buf, read_length);
 791                 break;
 792         case I2C_SMBUS_BLOCK_DATA:
 793                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 794                         ret = -EPROTO;
 795                         goto power_normal;
 796                 }
 797
 798                 memcpy(data->block, buf, read_length);
 799                 break;
 800         }
 801
 802         ret = 0;
 803 power_normal:
 804         hid_hw_power(hdev, PM_HINT_NORMAL);
 805         hid_dbg(hdev, "transfer finished: %d\n", ret);
 806         return ret;
 807 }
 808
 809 static u32 cp2112_functionality(struct i2c_adapter *adap)
 810 {
 811         return I2C_FUNC_I2C |
 812                 I2C_FUNC_SMBUS_BYTE |
 813                 I2C_FUNC_SMBUS_BYTE_DATA |
 814                 I2C_FUNC_SMBUS_WORD_DATA |
 815                 I2C_FUNC_SMBUS_BLOCK_DATA |
 816                 I2C_FUNC_SMBUS_I2C_BLOCK |
 817                 I2C_FUNC_SMBUS_PROC_CALL |
 818                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 819 }
 820
 821 static const struct i2c_algorithm smbus_algorithm = {
 822         .master_xfer    = cp2112_i2c_xfer,
 823         .smbus_xfer     = cp2112_xfer,
 824         .functionality  = cp2112_functionality,
 825 };
 826
 827 static int cp2112_get_usb_config(struct hid_device *hdev,
 828                                  struct cp2112_usb_config_report *cfg)
 829 {
 830         int ret;
 831
 832         ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
 833                              HID_FEATURE_REPORT);
 834         if (ret != sizeof(*cfg)) {
 835                 hid_err(hdev, "error reading usb config: %d\n", ret);
 836                 if (ret < 0)
 837                         return ret;
 838                 return -EIO;
 839         }
 840
 841         return 0;
 842 }
 843
 844 static int cp2112_set_usb_config(struct hid_device *hdev,
 845                                  struct cp2112_usb_config_report *cfg)
 846 {
 847         int ret;
 848
 849         BUG_ON(cfg->report != CP2112_USB_CONFIG);
 850
 851         ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
 852                                 HID_FEATURE_REPORT);
 853         if (ret != sizeof(*cfg)) {
 854                 hid_err(hdev, "error writing usb config: %d\n", ret);
 855                 if (ret < 0)
 856                         return ret;
 857                 return -EIO;
 858         }
 859
 860         return 0;
 861 }
 862
 863 static void chmod_sysfs_attrs(struct hid_device *hdev);
 864
 865 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
 866 static ssize_t name##_store(struct device *kdev, \
 867                             struct device_attribute *attr, const char *buf, \
 868                             size_t count) \
 869 { \
 870         struct hid_device *hdev = to_hid_device(kdev); \
 871         struct cp2112_usb_config_report cfg; \
 872         int ret = cp2112_get_usb_config(hdev, &cfg); \
 873         if (ret) \
 874                 return ret; \
 875         store; \
 876         ret = cp2112_set_usb_config(hdev, &cfg); \
 877         if (ret) \
 878                 return ret; \
 879         chmod_sysfs_attrs(hdev); \
 880         return count; \
 881 } \
 882 static ssize_t name##_show(struct device *kdev, \
 883                            struct device_attribute *attr, char *buf) \
 884 { \
 885         struct hid_device *hdev = to_hid_device(kdev); \
 886         struct cp2112_usb_config_report cfg; \
 887         int ret = cp2112_get_usb_config(hdev, &cfg); \
 888         if (ret) \
 889                 return ret; \
 890         return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
 891 } \
 892 static DEVICE_ATTR_RW(name);
 893
 894 CP2112_CONFIG_ATTR(vendor_id, ({
 895         u16 vid;
 896
 897         if (sscanf(buf, "%hi", &vid) != 1)
 898                 return -EINVAL;
 899
 900         cfg.vid = cpu_to_le16(vid);
 901         cfg.mask = 0x01;
 902 }), "0x%04x\n", le16_to_cpu(cfg.vid));
 903
 904 CP2112_CONFIG_ATTR(product_id, ({
 905         u16 pid;
 906
 907         if (sscanf(buf, "%hi", &pid) != 1)
 908                 return -EINVAL;
 909
 910         cfg.pid = cpu_to_le16(pid);
 911         cfg.mask = 0x02;
 912 }), "0x%04x\n", le16_to_cpu(cfg.pid));
 913
 914 CP2112_CONFIG_ATTR(max_power, ({
 915         int mA;
 916
 917         if (sscanf(buf, "%i", &mA) != 1)
 918                 return -EINVAL;
 919
 920         cfg.max_power = (mA + 1) / 2;
 921         cfg.mask = 0x04;
 922 }), "%u mA\n", cfg.max_power * 2);
 923
 924 CP2112_CONFIG_ATTR(power_mode, ({
 925         if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
 926                 return -EINVAL;
 927
 928         cfg.mask = 0x08;
 929 }), "%u\n", cfg.power_mode);
 930
 931 CP2112_CONFIG_ATTR(release_version, ({
 932         if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
 933             != 2)
 934                 return -EINVAL;
 935
 936         cfg.mask = 0x10;
 937 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
 938
 939 #undef CP2112_CONFIG_ATTR
 940
 941 struct cp2112_pstring_attribute {
 942         struct device_attribute attr;
 943         unsigned char report;
 944 };
 945
 946 static ssize_t pstr_store(struct device *kdev,
 947                           struct device_attribute *kattr, const char *buf,
 948                           size_t count)
 949 {
 950         struct hid_device *hdev = to_hid_device(kdev);
 951         struct cp2112_pstring_attribute *attr =
 952                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 953         struct cp2112_string_report report;
 954         int ret;
 955
 956         memset(&report, 0, sizeof(report));
 957
 958         ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 959                               report.string, ARRAY_SIZE(report.string));
 960         report.report = attr->report;
 961         report.length = ret * sizeof(report.string[0]) + 2;
 962         report.type = USB_DT_STRING;
 963
 964         ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
 965                                 HID_FEATURE_REPORT);
 966         if (ret != report.length + 1) {
 967                 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
 968                         ret);
 969                 if (ret < 0)
 970                         return ret;
 971                 return -EIO;
 972         }
 973
 974         chmod_sysfs_attrs(hdev);
 975         return count;
 976 }
 977
 978 static ssize_t pstr_show(struct device *kdev,
 979                          struct device_attribute *kattr, char *buf)
 980 {
 981         struct hid_device *hdev = to_hid_device(kdev);
 982         struct cp2112_pstring_attribute *attr =
 983                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 984         struct cp2112_string_report report;
 985         u8 length;
 986         int ret;
 987
 988         ret = cp2112_hid_get(hdev, attr->report, &report.report,
 989                              sizeof(report) - 1, HID_FEATURE_REPORT);
 990         if (ret < 3) {
 991                 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
 992                         ret);
 993                 if (ret < 0)
 994                         return ret;
 995                 return -EIO;
 996         }
 997
 998         if (report.length < 2) {
 999                 hid_err(hdev, "invalid %s string length: %d\n",
1000                         kattr->attr.name, report.length);
1001                 return -EIO;
1002         }
1003
1004         length = report.length > ret - 1 ? ret - 1 : report.length;
1005         length = (length - 2) / sizeof(report.string[0]);
1006         ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1007                               PAGE_SIZE - 1);
1008         buf[ret++] = '\n';
1009         return ret;
1010 }
1011
1012 #define CP2112_PSTR_ATTR(name, _report) \
1013 static struct cp2112_pstring_attribute dev_attr_##name = { \
1014         .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
1015         .report = _report, \
1016 };
1017
1018 CP2112_PSTR_ATTR(manufacturer,  CP2112_MANUFACTURER_STRING);
1019 CP2112_PSTR_ATTR(product,       CP2112_PRODUCT_STRING);
1020 CP2112_PSTR_ATTR(serial,        CP2112_SERIAL_STRING);
1021
1022 #undef CP2112_PSTR_ATTR
1023
1024 static const struct attribute_group cp2112_attr_group = {
1025         .attrs = (struct attribute *[]){
1026                 &dev_attr_vendor_id.attr,
1027                 &dev_attr_product_id.attr,
1028                 &dev_attr_max_power.attr,
1029                 &dev_attr_power_mode.attr,
1030                 &dev_attr_release_version.attr,
1031                 &dev_attr_manufacturer.attr.attr,
1032                 &dev_attr_product.attr.attr,
1033                 &dev_attr_serial.attr.attr,
1034                 NULL
1035         }
1036 };
1037
1038 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1039  * PROM have already been programmed. We do not depend on this preventing
1040  * writing to these attributes since the CP2112 will simply ignore writes to
1041  * already-programmed fields. This is why there is no sense in fixing this
1042  * racy behaviour.
1043  */
1044 static void chmod_sysfs_attrs(struct hid_device *hdev)
1045 {
1046         struct attribute **attr;
1047         u8 buf[2];
1048         int ret;
1049
1050         ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1051                              HID_FEATURE_REPORT);
1052         if (ret != sizeof(buf)) {
1053                 hid_err(hdev, "error reading lock byte: %d\n", ret);
1054                 return;
1055         }
1056
1057         for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1058                 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
1059                 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1060                 if (ret < 0)
1061                         hid_err(hdev, "error chmoding sysfs file %s\n",
1062                                 (*attr)->name);
1063                 buf[1] >>= 1;
1064         }
1065 }
1066
1067 static void cp2112_gpio_irq_ack(struct irq_data *d)
1068 {
1069 }
1070
1071 static void cp2112_gpio_irq_mask(struct irq_data *d)
1072 {
1073         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1074         struct cp2112_device *dev = gpiochip_get_data(gc);
1075
1076         __clear_bit(d->hwirq, &dev->irq_mask);
1077 }
1078
1079 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1080 {
1081         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1082         struct cp2112_device *dev = gpiochip_get_data(gc);
1083
1084         __set_bit(d->hwirq, &dev->irq_mask);
1085 }
1086
1087 static void cp2112_gpio_poll_callback(struct work_struct *work)
1088 {
1089         struct cp2112_device *dev = container_of(work, struct cp2112_device,
1090                                                  gpio_poll_worker.work);
1091         struct irq_data *d;
1092         u8 gpio_mask;
1093         u8 virqs = (u8)dev->irq_mask;
1094         u32 irq_type;
1095         int irq, virq, ret;
1096
1097         ret = cp2112_gpio_get_all(&dev->gc);
1098         if (ret == -ENODEV) /* the hardware has been disconnected */
1099                 return;
1100         if (ret < 0)
1101                 goto exit;
1102
1103         gpio_mask = ret;
1104
1105         while (virqs) {
1106                 virq = ffs(virqs) - 1;
1107                 virqs &= ~BIT(virq);
1108
1109                 if (!dev->gc.to_irq)
1110                         break;
1111
1112                 irq = dev->gc.to_irq(&dev->gc, virq);
1113
1114                 d = irq_get_irq_data(irq);
1115                 if (!d)
1116                         continue;
1117
1118                 irq_type = irqd_get_trigger_type(d);
1119
1120                 if (gpio_mask & BIT(virq)) {
1121                         /* Level High */
1122
1123                         if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1124                                 handle_nested_irq(irq);
1125
1126                         if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1127                             !(dev->gpio_prev_state & BIT(virq)))
1128                                 handle_nested_irq(irq);
1129                 } else {
1130                         /* Level Low */
1131
1132                         if (irq_type & IRQ_TYPE_LEVEL_LOW)
1133                                 handle_nested_irq(irq);
1134
1135                         if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1136                             (dev->gpio_prev_state & BIT(virq)))
1137                                 handle_nested_irq(irq);
1138                 }
1139         }
1140
1141         dev->gpio_prev_state = gpio_mask;
1142
1143 exit:
1144         if (dev->gpio_poll)
1145                 schedule_delayed_work(&dev->gpio_poll_worker, 10);
1146 }
1147
1148
1149 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1150 {
1151         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1152         struct cp2112_device *dev = gpiochip_get_data(gc);
1153
1154         INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1155
1156         if (!dev->gpio_poll) {
1157                 dev->gpio_poll = true;
1158                 schedule_delayed_work(&dev->gpio_poll_worker, 0);
1159         }
1160
1161         cp2112_gpio_irq_unmask(d);
1162         return 0;
1163 }
1164
1165 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1166 {
1167         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1168         struct cp2112_device *dev = gpiochip_get_data(gc);
1169
1170         cancel_delayed_work_sync(&dev->gpio_poll_worker);
1171 }
1172
1173 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1174 {
1175         return 0;
1176 }
1177
1178 static struct irq_chip cp2112_gpio_irqchip = {
1179         .name = "cp2112-gpio",
1180         .irq_startup = cp2112_gpio_irq_startup,
1181         .irq_shutdown = cp2112_gpio_irq_shutdown,
1182         .irq_ack = cp2112_gpio_irq_ack,
1183         .irq_mask = cp2112_gpio_irq_mask,
1184         .irq_unmask = cp2112_gpio_irq_unmask,
1185         .irq_set_type = cp2112_gpio_irq_type,
1186 };
1187
1188 static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
1189                                               int pin)
1190 {
1191         int ret;
1192
1193         if (dev->desc[pin])
1194                 return -EINVAL;
1195
1196         dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
1197                                                    "HID/I2C:Event",
1198                                                    GPIO_ACTIVE_HIGH,
1199                                                    GPIOD_IN);
1200         if (IS_ERR(dev->desc[pin])) {
1201                 dev_err(dev->gc.parent, "Failed to request GPIO\n");
1202                 return PTR_ERR(dev->desc[pin]);
1203         }
1204
1205         ret = cp2112_gpio_direction_input(&dev->gc, pin);
1206         if (ret < 0) {
1207                 dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n");
1208                 goto err_desc;
1209         }
1210
1211         ret = gpiochip_lock_as_irq(&dev->gc, pin);
1212         if (ret) {
1213                 dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
1214                 goto err_desc;
1215         }
1216
1217         ret = gpiod_to_irq(dev->desc[pin]);
1218         if (ret < 0) {
1219                 dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
1220                 goto err_lock;
1221         }
1222
1223         return ret;
1224
1225 err_lock:
1226         gpiochip_unlock_as_irq(&dev->gc, pin);
1227 err_desc:
1228         gpiochip_free_own_desc(dev->desc[pin]);
1229         dev->desc[pin] = NULL;
1230         return ret;
1231 }
1232
1233 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1234 {
1235         struct cp2112_device *dev;
1236         u8 buf[3];
1237         struct cp2112_smbus_config_report config;
1238         int ret;
1239
1240         dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1241         if (!dev)
1242                 return -ENOMEM;
1243
1244         dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1245                                           GFP_KERNEL);
1246         if (!dev->in_out_buffer)
1247                 return -ENOMEM;
1248
1249         mutex_init(&dev->lock);
1250
1251         ret = hid_parse(hdev);
1252         if (ret) {
1253                 hid_err(hdev, "parse failed\n");
1254                 return ret;
1255         }
1256
1257         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1258         if (ret) {
1259                 hid_err(hdev, "hw start failed\n");
1260                 return ret;
1261         }
1262
1263         ret = hid_hw_open(hdev);
1264         if (ret) {
1265                 hid_err(hdev, "hw open failed\n");
1266                 goto err_hid_stop;
1267         }
1268
1269         ret = hid_hw_power(hdev, PM_HINT_FULLON);
1270         if (ret < 0) {
1271                 hid_err(hdev, "power management error: %d\n", ret);
1272                 goto err_hid_close;
1273         }
1274
1275         ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1276                              HID_FEATURE_REPORT);
1277         if (ret != sizeof(buf)) {
1278                 hid_err(hdev, "error requesting version\n");
1279                 if (ret >= 0)
1280                         ret = -EIO;
1281                 goto err_power_normal;
1282         }
1283
1284         hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1285                  buf[1], buf[2]);
1286
1287         ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1288                              sizeof(config), HID_FEATURE_REPORT);
1289         if (ret != sizeof(config)) {
1290                 hid_err(hdev, "error requesting SMBus config\n");
1291                 if (ret >= 0)
1292                         ret = -EIO;
1293                 goto err_power_normal;
1294         }
1295
1296         config.retry_time = cpu_to_be16(1);
1297
1298         ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1299                                 HID_FEATURE_REPORT);
1300         if (ret != sizeof(config)) {
1301                 hid_err(hdev, "error setting SMBus config\n");
1302                 if (ret >= 0)
1303                         ret = -EIO;
1304                 goto err_power_normal;
1305         }
1306
1307         hid_set_drvdata(hdev, (void *)dev);
1308         dev->hdev               = hdev;
1309         dev->adap.owner         = THIS_MODULE;
1310         dev->adap.class         = I2C_CLASS_HWMON;
1311         dev->adap.algo          = &smbus_algorithm;
1312         dev->adap.algo_data     = dev;
1313         dev->adap.dev.parent    = &hdev->dev;
1314         snprintf(dev->adap.name, sizeof(dev->adap.name),
1315                  "CP2112 SMBus Bridge on hidraw%d",
1316                  ((struct hidraw *)hdev->hidraw)->minor);
1317         dev->hwversion = buf[2];
1318         init_waitqueue_head(&dev->wait);
1319
1320         hid_device_io_start(hdev);
1321         ret = i2c_add_adapter(&dev->adap);
1322         hid_device_io_stop(hdev);
1323
1324         if (ret) {
1325                 hid_err(hdev, "error registering i2c adapter\n");
1326                 goto err_power_normal;
1327         }
1328
1329         hid_dbg(hdev, "adapter registered\n");
1330
1331         dev->gc.label                   = "cp2112_gpio";
1332         dev->gc.direction_input         = cp2112_gpio_direction_input;
1333         dev->gc.direction_output        = cp2112_gpio_direction_output;
1334         dev->gc.set                     = cp2112_gpio_set;
1335         dev->gc.get                     = cp2112_gpio_get;
1336         dev->gc.base                    = -1;
1337         dev->gc.ngpio                   = 8;
1338         dev->gc.can_sleep               = 1;
1339         dev->gc.parent                  = &hdev->dev;
1340
1341         ret = gpiochip_add_data(&dev->gc, dev);
1342         if (ret < 0) {
1343                 hid_err(hdev, "error registering gpio chip\n");
1344                 goto err_free_i2c;
1345         }
1346
1347         ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1348         if (ret < 0) {
1349                 hid_err(hdev, "error creating sysfs attrs\n");
1350                 goto err_gpiochip_remove;
1351         }
1352
1353         chmod_sysfs_attrs(hdev);
1354         hid_hw_power(hdev, PM_HINT_NORMAL);
1355
1356         ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
1357                                    handle_simple_irq, IRQ_TYPE_NONE);
1358         if (ret) {
1359                 dev_err(dev->gc.parent, "failed to add IRQ chip\n");
1360                 goto err_sysfs_remove;
1361         }
1362
1363         return ret;
1364
1365 err_sysfs_remove:
1366         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1367 err_gpiochip_remove:
1368         gpiochip_remove(&dev->gc);
1369 err_free_i2c:
1370         i2c_del_adapter(&dev->adap);
1371 err_power_normal:
1372         hid_hw_power(hdev, PM_HINT_NORMAL);
1373 err_hid_close:
1374         hid_hw_close(hdev);
1375 err_hid_stop:
1376         hid_hw_stop(hdev);
1377         return ret;
1378 }
1379
1380 static void cp2112_remove(struct hid_device *hdev)
1381 {
1382         struct cp2112_device *dev = hid_get_drvdata(hdev);
1383         int i;
1384
1385         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1386         i2c_del_adapter(&dev->adap);
1387
1388         if (dev->gpio_poll) {
1389                 dev->gpio_poll = false;
1390                 cancel_delayed_work_sync(&dev->gpio_poll_worker);
1391         }
1392
1393         for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
1394                 gpiochip_unlock_as_irq(&dev->gc, i);
1395                 gpiochip_free_own_desc(dev->desc[i]);
1396         }
1397
1398         gpiochip_remove(&dev->gc);
1399         /* i2c_del_adapter has finished removing all i2c devices from our
1400          * adapter. Well behaved devices should no longer call our cp2112_xfer
1401          * and should have waited for any pending calls to finish. It has also
1402          * waited for device_unregister(&adap->dev) to complete. Therefore we
1403          * can safely free our struct cp2112_device.
1404          */
1405         hid_hw_close(hdev);
1406         hid_hw_stop(hdev);
1407 }
1408
1409 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1410                             u8 *data, int size)
1411 {
1412         struct cp2112_device *dev = hid_get_drvdata(hdev);
1413         struct cp2112_xfer_status_report *xfer = (void *)data;
1414
1415         switch (data[0]) {
1416         case CP2112_TRANSFER_STATUS_RESPONSE:
1417                 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1418                         xfer->status0, xfer->status1,
1419                         be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1420
1421                 switch (xfer->status0) {
1422                 case STATUS0_IDLE:
1423                         dev->xfer_status = -EAGAIN;
1424                         break;
1425                 case STATUS0_BUSY:
1426                         dev->xfer_status = -EBUSY;
1427                         break;
1428                 case STATUS0_COMPLETE:
1429                         dev->xfer_status = be16_to_cpu(xfer->length);
1430                         break;
1431                 case STATUS0_ERROR:
1432                         switch (xfer->status1) {
1433                         case STATUS1_TIMEOUT_NACK:
1434                         case STATUS1_TIMEOUT_BUS:
1435                                 dev->xfer_status = -ETIMEDOUT;
1436                                 break;
1437                         default:
1438                                 dev->xfer_status = -EIO;
1439                                 break;
1440                         }
1441                         break;
1442                 default:
1443                         dev->xfer_status = -EINVAL;
1444                         break;
1445                 }
1446
1447                 atomic_set(&dev->xfer_avail, 1);
1448                 break;
1449         case CP2112_DATA_READ_RESPONSE:
1450                 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1451
1452                 dev->read_length = data[2];
1453                 if (dev->read_length > sizeof(dev->read_data))
1454                         dev->read_length = sizeof(dev->read_data);
1455
1456                 memcpy(dev->read_data, &data[3], dev->read_length);
1457                 atomic_set(&dev->read_avail, 1);
1458                 break;
1459         default:
1460                 hid_err(hdev, "unknown report\n");
1461
1462                 return 0;
1463         }
1464
1465         wake_up_interruptible(&dev->wait);
1466         return 1;
1467 }
1468
1469 static struct hid_driver cp2112_driver = {
1470         .name           = "cp2112",
1471         .id_table       = cp2112_devices,
1472         .probe          = cp2112_probe,
1473         .remove         = cp2112_remove,
1474         .raw_event      = cp2112_raw_event,
1475 };
1476
1477 module_hid_driver(cp2112_driver);
1478 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1479 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1480 MODULE_LICENSE("GPL");
1481