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