drivers/hid/hid-cp2112.c

   1 /*
   2  * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
   3  * Copyright (c) 2013,2014 Uplogix, Inc.
   4  * David Barksdale <dbarksdale@uplogix.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  */
  15
  16 /*
  17  * The Silicon Labs CP2112 chip is a USB HID device which provides an
  18  * SMBus controller for talking to slave devices and 8 GPIO pins. The
  19  * host communicates with the CP2112 via raw HID reports.
  20  *
  21  * Data Sheet:
  22  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
  23  * Programming Interface Specification:
  24  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
  25  */
  26
  27 #include <linux/gpio.h>
  28 #include <linux/hid.h>
  29 #include <linux/i2c.h>
  30 #include <linux/module.h>
  31 #include <linux/nls.h>
  32 #include <linux/usb/ch9.h>
  33 #include "hid-ids.h"
  34
  35 enum {
  36         CP2112_GPIO_CONFIG              = 0x02,
  37         CP2112_GPIO_GET                 = 0x03,
  38         CP2112_GPIO_SET                 = 0x04,
  39         CP2112_GET_VERSION_INFO         = 0x05,
  40         CP2112_SMBUS_CONFIG             = 0x06,
  41         CP2112_DATA_READ_REQUEST        = 0x10,
  42         CP2112_DATA_WRITE_READ_REQUEST  = 0x11,
  43         CP2112_DATA_READ_FORCE_SEND     = 0x12,
  44         CP2112_DATA_READ_RESPONSE       = 0x13,
  45         CP2112_DATA_WRITE_REQUEST       = 0x14,
  46         CP2112_TRANSFER_STATUS_REQUEST  = 0x15,
  47         CP2112_TRANSFER_STATUS_RESPONSE = 0x16,
  48         CP2112_CANCEL_TRANSFER          = 0x17,
  49         CP2112_LOCK_BYTE                = 0x20,
  50         CP2112_USB_CONFIG               = 0x21,
  51         CP2112_MANUFACTURER_STRING      = 0x22,
  52         CP2112_PRODUCT_STRING           = 0x23,
  53         CP2112_SERIAL_STRING            = 0x24,
  54 };
  55
  56 enum {
  57         STATUS0_IDLE            = 0x00,
  58         STATUS0_BUSY            = 0x01,
  59         STATUS0_COMPLETE        = 0x02,
  60         STATUS0_ERROR           = 0x03,
  61 };
  62
  63 enum {
  64         STATUS1_TIMEOUT_NACK            = 0x00,
  65         STATUS1_TIMEOUT_BUS             = 0x01,
  66         STATUS1_ARBITRATION_LOST        = 0x02,
  67         STATUS1_READ_INCOMPLETE         = 0x03,
  68         STATUS1_WRITE_INCOMPLETE        = 0x04,
  69         STATUS1_SUCCESS                 = 0x05,
  70 };
  71
  72 struct cp2112_smbus_config_report {
  73         u8 report;              /* CP2112_SMBUS_CONFIG */
  74         __be32 clock_speed;     /* Hz */
  75         u8 device_address;      /* Stored in the upper 7 bits */
  76         u8 auto_send_read;      /* 1 = enabled, 0 = disabled */
  77         __be16 write_timeout;   /* ms, 0 = no timeout */
  78         __be16 read_timeout;    /* ms, 0 = no timeout */
  79         u8 scl_low_timeout;     /* 1 = enabled, 0 = disabled */
  80         __be16 retry_time;      /* # of retries, 0 = no limit */
  81 } __packed;
  82
  83 struct cp2112_usb_config_report {
  84         u8 report;      /* CP2112_USB_CONFIG */
  85         __le16 vid;     /* Vendor ID */
  86         __le16 pid;     /* Product ID */
  87         u8 max_power;   /* Power requested in 2mA units */
  88         u8 power_mode;  /* 0x00 = bus powered
  89                            0x01 = self powered & regulator off
  90                            0x02 = self powered & regulator on */
  91         u8 release_major;
  92         u8 release_minor;
  93         u8 mask;        /* What fields to program */
  94 } __packed;
  95
  96 struct cp2112_read_req_report {
  97         u8 report;      /* CP2112_DATA_READ_REQUEST */
  98         u8 slave_address;
  99         __be16 length;
 100 } __packed;
 101
 102 struct cp2112_write_read_req_report {
 103         u8 report;      /* CP2112_DATA_WRITE_READ_REQUEST */
 104         u8 slave_address;
 105         __be16 length;
 106         u8 target_address_length;
 107         u8 target_address[16];
 108 } __packed;
 109
 110 struct cp2112_write_req_report {
 111         u8 report;      /* CP2112_DATA_WRITE_REQUEST */
 112         u8 slave_address;
 113         u8 length;
 114         u8 data[61];
 115 } __packed;
 116
 117 struct cp2112_force_read_report {
 118         u8 report;      /* CP2112_DATA_READ_FORCE_SEND */
 119         __be16 length;
 120 } __packed;
 121
 122 struct cp2112_xfer_status_report {
 123         u8 report;      /* CP2112_TRANSFER_STATUS_RESPONSE */
 124         u8 status0;     /* STATUS0_* */
 125         u8 status1;     /* STATUS1_* */
 126         __be16 retries;
 127         __be16 length;
 128 } __packed;
 129
 130 struct cp2112_string_report {
 131         u8 dummy;               /* force .string to be aligned */
 132         u8 report;              /* CP2112_*_STRING */
 133         u8 length;              /* length in bytes of everyting after .report */
 134         u8 type;                /* USB_DT_STRING */
 135         wchar_t string[30];     /* UTF16_LITTLE_ENDIAN string */
 136 } __packed;
 137
 138 /* Number of times to request transfer status before giving up waiting for a
 139    transfer to complete. This may need to be changed if SMBUS clock, retries,
 140    or read/write/scl_low timeout settings are changed. */
 141 static const int XFER_STATUS_RETRIES = 10;
 142
 143 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
 144    CP2112_TRANSFER_STATUS_RESPONSE. */
 145 static const int RESPONSE_TIMEOUT = 50;
 146
 147 static const struct hid_device_id cp2112_devices[] = {
 148         { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
 149         { }
 150 };
 151 MODULE_DEVICE_TABLE(hid, cp2112_devices);
 152
 153 struct cp2112_device {
 154         struct i2c_adapter adap;
 155         struct hid_device *hdev;
 156         wait_queue_head_t wait;
 157         u8 read_data[61];
 158         u8 read_length;
 159         int xfer_status;
 160         atomic_t read_avail;
 161         atomic_t xfer_avail;
 162         struct gpio_chip gc;
 163 };
 164
 165 static int gpio_push_pull = 0xFF;
 166 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
 167 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
 168
 169 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 170 {
 171         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 172                                                  gc);
 173         struct hid_device *hdev = dev->hdev;
 174         u8 buf[5];
 175         int ret;
 176
 177         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 178                                        sizeof(buf), HID_FEATURE_REPORT,
 179                                        HID_REQ_GET_REPORT);
 180         if (ret != sizeof(buf)) {
 181                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 182                 return ret;
 183         }
 184
 185         buf[1] &= ~(1 << offset);
 186         buf[2] = gpio_push_pull;
 187
 188         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
 189                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 190         if (ret < 0) {
 191                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 192                 return ret;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 199 {
 200         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 201                                                  gc);
 202         struct hid_device *hdev = dev->hdev;
 203         u8 buf[3];
 204         int ret;
 205
 206         buf[0] = CP2112_GPIO_SET;
 207         buf[1] = value ? 0xff : 0;
 208         buf[2] = 1 << offset;
 209
 210         ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
 211                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 212         if (ret < 0)
 213                 hid_err(hdev, "error setting GPIO values: %d\n", ret);
 214 }
 215
 216 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
 217 {
 218         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 219                                                  gc);
 220         struct hid_device *hdev = dev->hdev;
 221         u8 buf[2];
 222         int ret;
 223
 224         ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
 225                                        HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
 226         if (ret != sizeof(buf)) {
 227                 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
 228                 return ret;
 229         }
 230
 231         return (buf[1] >> offset) & 1;
 232 }
 233
 234 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
 235                                         unsigned offset, int value)
 236 {
 237         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 238                                                  gc);
 239         struct hid_device *hdev = dev->hdev;
 240         u8 buf[5];
 241         int ret;
 242
 243         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 244                                        sizeof(buf), HID_FEATURE_REPORT,
 245                                        HID_REQ_GET_REPORT);
 246         if (ret != sizeof(buf)) {
 247                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 248                 return ret;
 249         }
 250
 251         buf[1] |= 1 << offset;
 252         buf[2] = gpio_push_pull;
 253
 254         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
 255                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 256         if (ret < 0) {
 257                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 258                 return ret;
 259         }
 260
 261         /*
 262          * Set gpio value when output direction is already set,
 263          * as specified in AN495, Rev. 0.2, cpt. 4.4
 264          */
 265         cp2112_gpio_set(chip, offset, value);
 266
 267         return 0;
 268 }
 269
 270 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
 271                           u8 *data, size_t count, unsigned char report_type)
 272 {
 273         u8 *buf;
 274         int ret;
 275
 276         buf = kmalloc(count, GFP_KERNEL);
 277         if (!buf)
 278                 return -ENOMEM;
 279
 280         ret = hid_hw_raw_request(hdev, report_number, buf, count,
 281                                        report_type, HID_REQ_GET_REPORT);
 282         memcpy(data, buf, count);
 283         kfree(buf);
 284         return ret;
 285 }
 286
 287 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
 288                              unsigned char report_type)
 289 {
 290         u8 *buf;
 291         int ret;
 292
 293         buf = kmemdup(data, count, GFP_KERNEL);
 294         if (!buf)
 295                 return -ENOMEM;
 296
 297         if (report_type == HID_OUTPUT_REPORT)
 298                 ret = hid_hw_output_report(hdev, buf, count);
 299         else
 300                 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
 301                                 HID_REQ_SET_REPORT);
 302
 303         kfree(buf);
 304         return ret;
 305 }
 306
 307 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
 308 {
 309         int ret = 0;
 310
 311         /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
 312          * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
 313          * come in cp2112_raw_event or timeout. There will only be one of these
 314          * in flight at any one time. The timeout is extremely large and is a
 315          * last resort if the CP2112 has died. If we do timeout we don't expect
 316          * to receive the response which would cause data races, it's not like
 317          * we can do anything about it anyway.
 318          */
 319         ret = wait_event_interruptible_timeout(dev->wait,
 320                 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
 321         if (-ERESTARTSYS == ret)
 322                 return ret;
 323         if (!ret)
 324                 return -ETIMEDOUT;
 325
 326         atomic_set(avail, 0);
 327         return 0;
 328 }
 329
 330 static int cp2112_xfer_status(struct cp2112_device *dev)
 331 {
 332         struct hid_device *hdev = dev->hdev;
 333         u8 buf[2];
 334         int ret;
 335
 336         buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
 337         buf[1] = 0x01;
 338         atomic_set(&dev->xfer_avail, 0);
 339
 340         ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 341         if (ret < 0) {
 342                 hid_warn(hdev, "Error requesting status: %d\n", ret);
 343                 return ret;
 344         }
 345
 346         ret = cp2112_wait(dev, &dev->xfer_avail);
 347         if (ret)
 348                 return ret;
 349
 350         return dev->xfer_status;
 351 }
 352
 353 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 354 {
 355         struct hid_device *hdev = dev->hdev;
 356         struct cp2112_force_read_report report;
 357         int ret;
 358
 359         report.report = CP2112_DATA_READ_FORCE_SEND;
 360         report.length = cpu_to_be16(size);
 361
 362         atomic_set(&dev->read_avail, 0);
 363
 364         ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
 365                                 HID_OUTPUT_REPORT);
 366         if (ret < 0) {
 367                 hid_warn(hdev, "Error requesting data: %d\n", ret);
 368                 return ret;
 369         }
 370
 371         ret = cp2112_wait(dev, &dev->read_avail);
 372         if (ret)
 373                 return ret;
 374
 375         hid_dbg(hdev, "read %d of %zd bytes requested\n",
 376                 dev->read_length, size);
 377
 378         if (size > dev->read_length)
 379                 size = dev->read_length;
 380
 381         memcpy(data, dev->read_data, size);
 382         return dev->read_length;
 383 }
 384
 385 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
 386 {
 387         struct cp2112_read_req_report *report = buf;
 388
 389         if (length < 1 || length > 512)
 390                 return -EINVAL;
 391
 392         report->report = CP2112_DATA_READ_REQUEST;
 393         report->slave_address = slave_address << 1;
 394         report->length = cpu_to_be16(length);
 395         return sizeof(*report);
 396 }
 397
 398 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
 399                                  u8 command, u8 *data, u8 data_length)
 400 {
 401         struct cp2112_write_read_req_report *report = buf;
 402
 403         if (length < 1 || length > 512
 404             || data_length > sizeof(report->target_address) - 1)
 405                 return -EINVAL;
 406
 407         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 408         report->slave_address = slave_address << 1;
 409         report->length = cpu_to_be16(length);
 410         report->target_address_length = data_length + 1;
 411         report->target_address[0] = command;
 412         memcpy(&report->target_address[1], data, data_length);
 413         return data_length + 6;
 414 }
 415
 416 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
 417                             u8 data_length)
 418 {
 419         struct cp2112_write_req_report *report = buf;
 420
 421         if (data_length > sizeof(report->data) - 1)
 422                 return -EINVAL;
 423
 424         report->report = CP2112_DATA_WRITE_REQUEST;
 425         report->slave_address = slave_address << 1;
 426         report->length = data_length + 1;
 427         report->data[0] = command;
 428         memcpy(&report->data[1], data, data_length);
 429         return data_length + 4;
 430 }
 431
 432 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 433                        unsigned short flags, char read_write, u8 command,
 434                        int size, union i2c_smbus_data *data)
 435 {
 436         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 437         struct hid_device *hdev = dev->hdev;
 438         u8 buf[64];
 439         __be16 word;
 440         ssize_t count;
 441         size_t read_length = 0;
 442         unsigned int retries;
 443         int ret;
 444
 445         hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
 446                 read_write == I2C_SMBUS_WRITE ? "write" : "read",
 447                 addr, flags, command, size);
 448
 449         switch (size) {
 450         case I2C_SMBUS_BYTE:
 451                 read_length = 1;
 452
 453                 if (I2C_SMBUS_READ == read_write)
 454                         count = cp2112_read_req(buf, addr, read_length);
 455                 else
 456                         count = cp2112_write_req(buf, addr, data->byte, NULL,
 457                                                  0);
 458                 break;
 459         case I2C_SMBUS_BYTE_DATA:
 460                 read_length = 1;
 461
 462                 if (I2C_SMBUS_READ == read_write)
 463                         count = cp2112_write_read_req(buf, addr, read_length,
 464                                                       command, NULL, 0);
 465                 else
 466                         count = cp2112_write_req(buf, addr, command,
 467                                                  &data->byte, 1);
 468                 break;
 469         case I2C_SMBUS_WORD_DATA:
 470                 read_length = 2;
 471                 word = cpu_to_be16(data->word);
 472
 473                 if (I2C_SMBUS_READ == read_write)
 474                         count = cp2112_write_read_req(buf, addr, read_length,
 475                                                       command, NULL, 0);
 476                 else
 477                         count = cp2112_write_req(buf, addr, command,
 478                                                  (u8 *)&word, 2);
 479                 break;
 480         case I2C_SMBUS_PROC_CALL:
 481                 size = I2C_SMBUS_WORD_DATA;
 482                 read_write = I2C_SMBUS_READ;
 483                 read_length = 2;
 484                 word = cpu_to_be16(data->word);
 485
 486                 count = cp2112_write_read_req(buf, addr, read_length, command,
 487                                               (u8 *)&word, 2);
 488                 break;
 489         case I2C_SMBUS_I2C_BLOCK_DATA:
 490                 size = I2C_SMBUS_BLOCK_DATA;
 491                 /* fallthrough */
 492         case I2C_SMBUS_BLOCK_DATA:
 493                 if (I2C_SMBUS_READ == read_write) {
 494                         count = cp2112_write_read_req(buf, addr,
 495                                                       I2C_SMBUS_BLOCK_MAX,
 496                                                       command, NULL, 0);
 497                 } else {
 498                         count = cp2112_write_req(buf, addr, command,
 499                                                  data->block,
 500                                                  data->block[0] + 1);
 501                 }
 502                 break;
 503         case I2C_SMBUS_BLOCK_PROC_CALL:
 504                 size = I2C_SMBUS_BLOCK_DATA;
 505                 read_write = I2C_SMBUS_READ;
 506
 507                 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
 508                                               command, data->block,
 509                                               data->block[0] + 1);
 510                 break;
 511         default:
 512                 hid_warn(hdev, "Unsupported transaction %d\n", size);
 513                 return -EOPNOTSUPP;
 514         }
 515
 516         if (count < 0)
 517                 return count;
 518
 519         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 520         if (ret < 0) {
 521                 hid_err(hdev, "power management error: %d\n", ret);
 522                 return ret;
 523         }
 524
 525         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 526         if (ret < 0) {
 527                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 528                 goto power_normal;
 529         }
 530
 531         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 532                 ret = cp2112_xfer_status(dev);
 533                 if (-EBUSY == ret)
 534                         continue;
 535                 if (ret < 0)
 536                         goto power_normal;
 537                 break;
 538         }
 539
 540         if (XFER_STATUS_RETRIES <= retries) {
 541                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 542                 buf[0] = CP2112_CANCEL_TRANSFER;
 543                 buf[1] = 0x01;
 544
 545                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 546                 if (ret < 0)
 547                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 548                                  ret);
 549
 550                 ret = -ETIMEDOUT;
 551                 goto power_normal;
 552         }
 553
 554         if (I2C_SMBUS_WRITE == read_write) {
 555                 ret = 0;
 556                 goto power_normal;
 557         }
 558
 559         if (I2C_SMBUS_BLOCK_DATA == size)
 560                 read_length = ret;
 561
 562         ret = cp2112_read(dev, buf, read_length);
 563         if (ret < 0)
 564                 goto power_normal;
 565         if (ret != read_length) {
 566                 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
 567                 ret = -EIO;
 568                 goto power_normal;
 569         }
 570
 571         switch (size) {
 572         case I2C_SMBUS_BYTE:
 573         case I2C_SMBUS_BYTE_DATA:
 574                 data->byte = buf[0];
 575                 break;
 576         case I2C_SMBUS_WORD_DATA:
 577                 data->word = be16_to_cpup((__be16 *)buf);
 578                 break;
 579         case I2C_SMBUS_BLOCK_DATA:
 580                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 581                         ret = -EPROTO;
 582                         goto power_normal;
 583                 }
 584
 585                 memcpy(data->block, buf, read_length);
 586                 break;
 587         }
 588
 589         ret = 0;
 590 power_normal:
 591         hid_hw_power(hdev, PM_HINT_NORMAL);
 592         hid_dbg(hdev, "transfer finished: %d\n", ret);
 593         return ret;
 594 }
 595
 596 static u32 cp2112_functionality(struct i2c_adapter *adap)
 597 {
 598         return I2C_FUNC_SMBUS_BYTE |
 599                 I2C_FUNC_SMBUS_BYTE_DATA |
 600                 I2C_FUNC_SMBUS_WORD_DATA |
 601                 I2C_FUNC_SMBUS_BLOCK_DATA |
 602                 I2C_FUNC_SMBUS_I2C_BLOCK |
 603                 I2C_FUNC_SMBUS_PROC_CALL |
 604                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 605 }
 606
 607 static const struct i2c_algorithm smbus_algorithm = {
 608         .smbus_xfer     = cp2112_xfer,
 609         .functionality  = cp2112_functionality,
 610 };
 611
 612 static int cp2112_get_usb_config(struct hid_device *hdev,
 613                                  struct cp2112_usb_config_report *cfg)
 614 {
 615         int ret;
 616
 617         ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
 618                              HID_FEATURE_REPORT);
 619         if (ret != sizeof(*cfg)) {
 620                 hid_err(hdev, "error reading usb config: %d\n", ret);
 621                 if (ret < 0)
 622                         return ret;
 623                 return -EIO;
 624         }
 625
 626         return 0;
 627 }
 628
 629 static int cp2112_set_usb_config(struct hid_device *hdev,
 630                                  struct cp2112_usb_config_report *cfg)
 631 {
 632         int ret;
 633
 634         BUG_ON(cfg->report != CP2112_USB_CONFIG);
 635
 636         ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
 637                                 HID_FEATURE_REPORT);
 638         if (ret != sizeof(*cfg)) {
 639                 hid_err(hdev, "error writing usb config: %d\n", ret);
 640                 if (ret < 0)
 641                         return ret;
 642                 return -EIO;
 643         }
 644
 645         return 0;
 646 }
 647
 648 static void chmod_sysfs_attrs(struct hid_device *hdev);
 649
 650 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
 651 static ssize_t name##_store(struct device *kdev, \
 652                             struct device_attribute *attr, const char *buf, \
 653                             size_t count) \
 654 { \
 655         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 656         struct cp2112_usb_config_report cfg; \
 657         int ret = cp2112_get_usb_config(hdev, &cfg); \
 658         if (ret) \
 659                 return ret; \
 660         store; \
 661         ret = cp2112_set_usb_config(hdev, &cfg); \
 662         if (ret) \
 663                 return ret; \
 664         chmod_sysfs_attrs(hdev); \
 665         return count; \
 666 } \
 667 static ssize_t name##_show(struct device *kdev, \
 668                            struct device_attribute *attr, char *buf) \
 669 { \
 670         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 671         struct cp2112_usb_config_report cfg; \
 672         int ret = cp2112_get_usb_config(hdev, &cfg); \
 673         if (ret) \
 674                 return ret; \
 675         return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
 676 } \
 677 static DEVICE_ATTR_RW(name);
 678
 679 CP2112_CONFIG_ATTR(vendor_id, ({
 680         u16 vid;
 681
 682         if (sscanf(buf, "%hi", &vid) != 1)
 683                 return -EINVAL;
 684
 685         cfg.vid = cpu_to_le16(vid);
 686         cfg.mask = 0x01;
 687 }), "0x%04x\n", le16_to_cpu(cfg.vid));
 688
 689 CP2112_CONFIG_ATTR(product_id, ({
 690         u16 pid;
 691
 692         if (sscanf(buf, "%hi", &pid) != 1)
 693                 return -EINVAL;
 694
 695         cfg.pid = cpu_to_le16(pid);
 696         cfg.mask = 0x02;
 697 }), "0x%04x\n", le16_to_cpu(cfg.pid));
 698
 699 CP2112_CONFIG_ATTR(max_power, ({
 700         int mA;
 701
 702         if (sscanf(buf, "%i", &mA) != 1)
 703                 return -EINVAL;
 704
 705         cfg.max_power = (mA + 1) / 2;
 706         cfg.mask = 0x04;
 707 }), "%u mA\n", cfg.max_power * 2);
 708
 709 CP2112_CONFIG_ATTR(power_mode, ({
 710         if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
 711                 return -EINVAL;
 712
 713         cfg.mask = 0x08;
 714 }), "%u\n", cfg.power_mode);
 715
 716 CP2112_CONFIG_ATTR(release_version, ({
 717         if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
 718             != 2)
 719                 return -EINVAL;
 720
 721         cfg.mask = 0x10;
 722 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
 723
 724 #undef CP2112_CONFIG_ATTR
 725
 726 struct cp2112_pstring_attribute {
 727         struct device_attribute attr;
 728         unsigned char report;
 729 };
 730
 731 static ssize_t pstr_store(struct device *kdev,
 732                           struct device_attribute *kattr, const char *buf,
 733                           size_t count)
 734 {
 735         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 736         struct cp2112_pstring_attribute *attr =
 737                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 738         struct cp2112_string_report report;
 739         int ret;
 740
 741         memset(&report, 0, sizeof(report));
 742
 743         ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 744                               report.string, ARRAY_SIZE(report.string));
 745         report.report = attr->report;
 746         report.length = ret * sizeof(report.string[0]) + 2;
 747         report.type = USB_DT_STRING;
 748
 749         ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
 750                                 HID_FEATURE_REPORT);
 751         if (ret != report.length + 1) {
 752                 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
 753                         ret);
 754                 if (ret < 0)
 755                         return ret;
 756                 return -EIO;
 757         }
 758
 759         chmod_sysfs_attrs(hdev);
 760         return count;
 761 }
 762
 763 static ssize_t pstr_show(struct device *kdev,
 764                          struct device_attribute *kattr, char *buf)
 765 {
 766         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 767         struct cp2112_pstring_attribute *attr =
 768                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 769         struct cp2112_string_report report;
 770         u8 length;
 771         int ret;
 772
 773         ret = cp2112_hid_get(hdev, attr->report, &report.report,
 774                              sizeof(report) - 1, HID_FEATURE_REPORT);
 775         if (ret < 3) {
 776                 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
 777                         ret);
 778                 if (ret < 0)
 779                         return ret;
 780                 return -EIO;
 781         }
 782
 783         if (report.length < 2) {
 784                 hid_err(hdev, "invalid %s string length: %d\n",
 785                         kattr->attr.name, report.length);
 786                 return -EIO;
 787         }
 788
 789         length = report.length > ret - 1 ? ret - 1 : report.length;
 790         length = (length - 2) / sizeof(report.string[0]);
 791         ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
 792                               PAGE_SIZE - 1);
 793         buf[ret++] = '\n';
 794         return ret;
 795 }
 796
 797 #define CP2112_PSTR_ATTR(name, _report) \
 798 static struct cp2112_pstring_attribute dev_attr_##name = { \
 799         .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
 800         .report = _report, \
 801 };
 802
 803 CP2112_PSTR_ATTR(manufacturer,  CP2112_MANUFACTURER_STRING);
 804 CP2112_PSTR_ATTR(product,       CP2112_PRODUCT_STRING);
 805 CP2112_PSTR_ATTR(serial,        CP2112_SERIAL_STRING);
 806
 807 #undef CP2112_PSTR_ATTR
 808
 809 static const struct attribute_group cp2112_attr_group = {
 810         .attrs = (struct attribute *[]){
 811                 &dev_attr_vendor_id.attr,
 812                 &dev_attr_product_id.attr,
 813                 &dev_attr_max_power.attr,
 814                 &dev_attr_power_mode.attr,
 815                 &dev_attr_release_version.attr,
 816                 &dev_attr_manufacturer.attr.attr,
 817                 &dev_attr_product.attr.attr,
 818                 &dev_attr_serial.attr.attr,
 819                 NULL
 820         }
 821 };
 822
 823 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
 824  * PROM have already been programmed. We do not depend on this preventing
 825  * writing to these attributes since the CP2112 will simply ignore writes to
 826  * already-programmed fields. This is why there is no sense in fixing this
 827  * racy behaviour.
 828  */
 829 static void chmod_sysfs_attrs(struct hid_device *hdev)
 830 {
 831         struct attribute **attr;
 832         u8 buf[2];
 833         int ret;
 834
 835         ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
 836                              HID_FEATURE_REPORT);
 837         if (ret != sizeof(buf)) {
 838                 hid_err(hdev, "error reading lock byte: %d\n", ret);
 839                 return;
 840         }
 841
 842         for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
 843                 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
 844                 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
 845                 if (ret < 0)
 846                         hid_err(hdev, "error chmoding sysfs file %s\n",
 847                                 (*attr)->name);
 848                 buf[1] >>= 1;
 849         }
 850 }
 851
 852 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 853 {
 854         struct cp2112_device *dev;
 855         u8 buf[3];
 856         struct cp2112_smbus_config_report config;
 857         int ret;
 858
 859         ret = hid_parse(hdev);
 860         if (ret) {
 861                 hid_err(hdev, "parse failed\n");
 862                 return ret;
 863         }
 864
 865         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 866         if (ret) {
 867                 hid_err(hdev, "hw start failed\n");
 868                 return ret;
 869         }
 870
 871         ret = hid_hw_open(hdev);
 872         if (ret) {
 873                 hid_err(hdev, "hw open failed\n");
 874                 goto err_hid_stop;
 875         }
 876
 877         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 878         if (ret < 0) {
 879                 hid_err(hdev, "power management error: %d\n", ret);
 880                 goto err_hid_close;
 881         }
 882
 883         ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
 884                              HID_FEATURE_REPORT);
 885         if (ret != sizeof(buf)) {
 886                 hid_err(hdev, "error requesting version\n");
 887                 if (ret >= 0)
 888                         ret = -EIO;
 889                 goto err_power_normal;
 890         }
 891
 892         hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
 893                  buf[1], buf[2]);
 894
 895         ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
 896                              sizeof(config), HID_FEATURE_REPORT);
 897         if (ret != sizeof(config)) {
 898                 hid_err(hdev, "error requesting SMBus config\n");
 899                 if (ret >= 0)
 900                         ret = -EIO;
 901                 goto err_power_normal;
 902         }
 903
 904         config.retry_time = cpu_to_be16(1);
 905
 906         ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
 907                                 HID_FEATURE_REPORT);
 908         if (ret != sizeof(config)) {
 909                 hid_err(hdev, "error setting SMBus config\n");
 910                 if (ret >= 0)
 911                         ret = -EIO;
 912                 goto err_power_normal;
 913         }
 914
 915         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 916         if (!dev) {
 917                 ret = -ENOMEM;
 918                 goto err_power_normal;
 919         }
 920
 921         hid_set_drvdata(hdev, (void *)dev);
 922         dev->hdev               = hdev;
 923         dev->adap.owner         = THIS_MODULE;
 924         dev->adap.class         = I2C_CLASS_HWMON;
 925         dev->adap.algo          = &smbus_algorithm;
 926         dev->adap.algo_data     = dev;
 927         dev->adap.dev.parent    = &hdev->dev;
 928         snprintf(dev->adap.name, sizeof(dev->adap.name),
 929                  "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
 930         init_waitqueue_head(&dev->wait);
 931
 932         hid_device_io_start(hdev);
 933         ret = i2c_add_adapter(&dev->adap);
 934         hid_device_io_stop(hdev);
 935
 936         if (ret) {
 937                 hid_err(hdev, "error registering i2c adapter\n");
 938                 goto err_free_dev;
 939         }
 940
 941         hid_dbg(hdev, "adapter registered\n");
 942
 943         dev->gc.label                   = "cp2112_gpio";
 944         dev->gc.direction_input         = cp2112_gpio_direction_input;
 945         dev->gc.direction_output        = cp2112_gpio_direction_output;
 946         dev->gc.set                     = cp2112_gpio_set;
 947         dev->gc.get                     = cp2112_gpio_get;
 948         dev->gc.base                    = -1;
 949         dev->gc.ngpio                   = 8;
 950         dev->gc.can_sleep               = 1;
 951         dev->gc.dev                     = &hdev->dev;
 952
 953         ret = gpiochip_add(&dev->gc);
 954         if (ret < 0) {
 955                 hid_err(hdev, "error registering gpio chip\n");
 956                 goto err_free_i2c;
 957         }
 958
 959         ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
 960         if (ret < 0) {
 961                 hid_err(hdev, "error creating sysfs attrs\n");
 962                 goto err_gpiochip_remove;
 963         }
 964
 965         chmod_sysfs_attrs(hdev);
 966         hid_hw_power(hdev, PM_HINT_NORMAL);
 967
 968         return ret;
 969
 970 err_gpiochip_remove:
 971         if (gpiochip_remove(&dev->gc) < 0)
 972                 hid_err(hdev, "error removing gpio chip\n");
 973 err_free_i2c:
 974         i2c_del_adapter(&dev->adap);
 975 err_free_dev:
 976         kfree(dev);
 977 err_power_normal:
 978         hid_hw_power(hdev, PM_HINT_NORMAL);
 979 err_hid_close:
 980         hid_hw_close(hdev);
 981 err_hid_stop:
 982         hid_hw_stop(hdev);
 983         return ret;
 984 }
 985
 986 static void cp2112_remove(struct hid_device *hdev)
 987 {
 988         struct cp2112_device *dev = hid_get_drvdata(hdev);
 989
 990         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
 991         if (gpiochip_remove(&dev->gc))
 992                 hid_err(hdev, "unable to remove gpio chip\n");
 993         i2c_del_adapter(&dev->adap);
 994         /* i2c_del_adapter has finished removing all i2c devices from our
 995          * adapter. Well behaved devices should no longer call our cp2112_xfer
 996          * and should have waited for any pending calls to finish. It has also
 997          * waited for device_unregister(&adap->dev) to complete. Therefore we
 998          * can safely free our struct cp2112_device.
 999          */
1000         hid_hw_close(hdev);
1001         hid_hw_stop(hdev);
1002         kfree(dev);
1003 }
1004
1005 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1006                             u8 *data, int size)
1007 {
1008         struct cp2112_device *dev = hid_get_drvdata(hdev);
1009         struct cp2112_xfer_status_report *xfer = (void *)data;
1010
1011         switch (data[0]) {
1012         case CP2112_TRANSFER_STATUS_RESPONSE:
1013                 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1014                         xfer->status0, xfer->status1,
1015                         be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1016
1017                 switch (xfer->status0) {
1018                 case STATUS0_IDLE:
1019                         dev->xfer_status = -EAGAIN;
1020                         break;
1021                 case STATUS0_BUSY:
1022                         dev->xfer_status = -EBUSY;
1023                         break;
1024                 case STATUS0_COMPLETE:
1025                         dev->xfer_status = be16_to_cpu(xfer->length);
1026                         break;
1027                 case STATUS0_ERROR:
1028                         switch (xfer->status1) {
1029                         case STATUS1_TIMEOUT_NACK:
1030                         case STATUS1_TIMEOUT_BUS:
1031                                 dev->xfer_status = -ETIMEDOUT;
1032                                 break;
1033                         default:
1034                                 dev->xfer_status = -EIO;
1035                                 break;
1036                         }
1037                         break;
1038                 default:
1039                         dev->xfer_status = -EINVAL;
1040                         break;
1041                 }
1042
1043                 atomic_set(&dev->xfer_avail, 1);
1044                 break;
1045         case CP2112_DATA_READ_RESPONSE:
1046                 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1047
1048                 dev->read_length = data[2];
1049                 if (dev->read_length > sizeof(dev->read_data))
1050                         dev->read_length = sizeof(dev->read_data);
1051
1052                 memcpy(dev->read_data, &data[3], dev->read_length);
1053                 atomic_set(&dev->read_avail, 1);
1054                 break;
1055         default:
1056                 hid_err(hdev, "unknown report\n");
1057
1058                 return 0;
1059         }
1060
1061         wake_up_interruptible(&dev->wait);
1062         return 1;
1063 }
1064
1065 static struct hid_driver cp2112_driver = {
1066         .name           = "cp2112",
1067         .id_table       = cp2112_devices,
1068         .probe          = cp2112_probe,
1069         .remove         = cp2112_remove,
1070         .raw_event      = cp2112_raw_event,
1071 };
1072
1073 module_hid_driver(cp2112_driver);
1074 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1075 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1076 MODULE_LICENSE("GPL");
1077