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