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         cp2112_gpio_set(chip, offset, value);
 244
 245         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 246                                        sizeof(buf), HID_FEATURE_REPORT,
 247                                        HID_REQ_GET_REPORT);
 248         if (ret != sizeof(buf)) {
 249                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 250                 return ret;
 251         }
 252
 253         buf[1] |= 1 << offset;
 254         buf[2] = gpio_push_pull;
 255
 256         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
 257                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 258         if (ret < 0) {
 259                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 260                 return ret;
 261         }
 262
 263         return 0;
 264 }
 265
 266 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
 267                           u8 *data, size_t count, unsigned char report_type)
 268 {
 269         u8 *buf;
 270         int ret;
 271
 272         buf = kmalloc(count, GFP_KERNEL);
 273         if (!buf)
 274                 return -ENOMEM;
 275
 276         ret = hid_hw_raw_request(hdev, report_number, buf, count,
 277                                        report_type, HID_REQ_GET_REPORT);
 278         memcpy(data, buf, count);
 279         kfree(buf);
 280         return ret;
 281 }
 282
 283 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
 284                              unsigned char report_type)
 285 {
 286         u8 *buf;
 287         int ret;
 288
 289         buf = kmemdup(data, count, GFP_KERNEL);
 290         if (!buf)
 291                 return -ENOMEM;
 292
 293         if (report_type == HID_OUTPUT_REPORT)
 294                 ret = hid_hw_output_report(hdev, buf, count);
 295         else
 296                 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
 297                                 HID_REQ_SET_REPORT);
 298
 299         kfree(buf);
 300         return ret;
 301 }
 302
 303 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
 304 {
 305         int ret = 0;
 306
 307         /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
 308          * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
 309          * come in cp2112_raw_event or timeout. There will only be one of these
 310          * in flight at any one time. The timeout is extremely large and is a
 311          * last resort if the CP2112 has died. If we do timeout we don't expect
 312          * to receive the response which would cause data races, it's not like
 313          * we can do anything about it anyway.
 314          */
 315         ret = wait_event_interruptible_timeout(dev->wait,
 316                 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
 317         if (-ERESTARTSYS == ret)
 318                 return ret;
 319         if (!ret)
 320                 return -ETIMEDOUT;
 321
 322         atomic_set(avail, 0);
 323         return 0;
 324 }
 325
 326 static int cp2112_xfer_status(struct cp2112_device *dev)
 327 {
 328         struct hid_device *hdev = dev->hdev;
 329         u8 buf[2];
 330         int ret;
 331
 332         buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
 333         buf[1] = 0x01;
 334         atomic_set(&dev->xfer_avail, 0);
 335
 336         ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 337         if (ret < 0) {
 338                 hid_warn(hdev, "Error requesting status: %d\n", ret);
 339                 return ret;
 340         }
 341
 342         ret = cp2112_wait(dev, &dev->xfer_avail);
 343         if (ret)
 344                 return ret;
 345
 346         return dev->xfer_status;
 347 }
 348
 349 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 350 {
 351         struct hid_device *hdev = dev->hdev;
 352         struct cp2112_force_read_report report;
 353         int ret;
 354
 355         report.report = CP2112_DATA_READ_FORCE_SEND;
 356         report.length = cpu_to_be16(size);
 357
 358         atomic_set(&dev->read_avail, 0);
 359
 360         ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
 361                                 HID_OUTPUT_REPORT);
 362         if (ret < 0) {
 363                 hid_warn(hdev, "Error requesting data: %d\n", ret);
 364                 return ret;
 365         }
 366
 367         ret = cp2112_wait(dev, &dev->read_avail);
 368         if (ret)
 369                 return ret;
 370
 371         hid_dbg(hdev, "read %d of %zd bytes requested\n",
 372                 dev->read_length, size);
 373
 374         if (size > dev->read_length)
 375                 size = dev->read_length;
 376
 377         memcpy(data, dev->read_data, size);
 378         return dev->read_length;
 379 }
 380
 381 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
 382 {
 383         struct cp2112_read_req_report *report = buf;
 384
 385         if (length < 1 || length > 512)
 386                 return -EINVAL;
 387
 388         report->report = CP2112_DATA_READ_REQUEST;
 389         report->slave_address = slave_address << 1;
 390         report->length = cpu_to_be16(length);
 391         return sizeof(*report);
 392 }
 393
 394 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
 395                                  u8 command, u8 *data, u8 data_length)
 396 {
 397         struct cp2112_write_read_req_report *report = buf;
 398
 399         if (length < 1 || length > 512
 400             || data_length > sizeof(report->target_address) - 1)
 401                 return -EINVAL;
 402
 403         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 404         report->slave_address = slave_address << 1;
 405         report->length = cpu_to_be16(length);
 406         report->target_address_length = data_length + 1;
 407         report->target_address[0] = command;
 408         memcpy(&report->target_address[1], data, data_length);
 409         return data_length + 6;
 410 }
 411
 412 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
 413                             u8 data_length)
 414 {
 415         struct cp2112_write_req_report *report = buf;
 416
 417         if (data_length > sizeof(report->data) - 1)
 418                 return -EINVAL;
 419
 420         report->report = CP2112_DATA_WRITE_REQUEST;
 421         report->slave_address = slave_address << 1;
 422         report->length = data_length + 1;
 423         report->data[0] = command;
 424         memcpy(&report->data[1], data, data_length);
 425         return data_length + 4;
 426 }
 427
 428 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 429                        unsigned short flags, char read_write, u8 command,
 430                        int size, union i2c_smbus_data *data)
 431 {
 432         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 433         struct hid_device *hdev = dev->hdev;
 434         u8 buf[64];
 435         __be16 word;
 436         ssize_t count;
 437         size_t read_length = 0;
 438         unsigned int retries;
 439         int ret;
 440
 441         hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
 442                 read_write == I2C_SMBUS_WRITE ? "write" : "read",
 443                 addr, flags, command, size);
 444
 445         switch (size) {
 446         case I2C_SMBUS_BYTE:
 447                 read_length = 1;
 448
 449                 if (I2C_SMBUS_READ == read_write)
 450                         count = cp2112_read_req(buf, addr, read_length);
 451                 else
 452                         count = cp2112_write_req(buf, addr, data->byte, NULL,
 453                                                  0);
 454                 break;
 455         case I2C_SMBUS_BYTE_DATA:
 456                 read_length = 1;
 457
 458                 if (I2C_SMBUS_READ == read_write)
 459                         count = cp2112_write_read_req(buf, addr, read_length,
 460                                                       command, NULL, 0);
 461                 else
 462                         count = cp2112_write_req(buf, addr, command,
 463                                                  &data->byte, 1);
 464                 break;
 465         case I2C_SMBUS_WORD_DATA:
 466                 read_length = 2;
 467                 word = cpu_to_be16(data->word);
 468
 469                 if (I2C_SMBUS_READ == read_write)
 470                         count = cp2112_write_read_req(buf, addr, read_length,
 471                                                       command, NULL, 0);
 472                 else
 473                         count = cp2112_write_req(buf, addr, command,
 474                                                  (u8 *)&word, 2);
 475                 break;
 476         case I2C_SMBUS_PROC_CALL:
 477                 size = I2C_SMBUS_WORD_DATA;
 478                 read_write = I2C_SMBUS_READ;
 479                 read_length = 2;
 480                 word = cpu_to_be16(data->word);
 481
 482                 count = cp2112_write_read_req(buf, addr, read_length, command,
 483                                               (u8 *)&word, 2);
 484                 break;
 485         case I2C_SMBUS_I2C_BLOCK_DATA:
 486                 size = I2C_SMBUS_BLOCK_DATA;
 487                 /* fallthrough */
 488         case I2C_SMBUS_BLOCK_DATA:
 489                 if (I2C_SMBUS_READ == read_write) {
 490                         count = cp2112_write_read_req(buf, addr,
 491                                                       I2C_SMBUS_BLOCK_MAX,
 492                                                       command, NULL, 0);
 493                 } else {
 494                         count = cp2112_write_req(buf, addr, command,
 495                                                  data->block,
 496                                                  data->block[0] + 1);
 497                 }
 498                 break;
 499         case I2C_SMBUS_BLOCK_PROC_CALL:
 500                 size = I2C_SMBUS_BLOCK_DATA;
 501                 read_write = I2C_SMBUS_READ;
 502
 503                 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
 504                                               command, data->block,
 505                                               data->block[0] + 1);
 506                 break;
 507         default:
 508                 hid_warn(hdev, "Unsupported transaction %d\n", size);
 509                 return -EOPNOTSUPP;
 510         }
 511
 512         if (count < 0)
 513                 return count;
 514
 515         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 516         if (ret < 0) {
 517                 hid_err(hdev, "power management error: %d\n", ret);
 518                 return ret;
 519         }
 520
 521         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 522         if (ret < 0) {
 523                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 524                 goto power_normal;
 525         }
 526
 527         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 528                 ret = cp2112_xfer_status(dev);
 529                 if (-EBUSY == ret)
 530                         continue;
 531                 if (ret < 0)
 532                         goto power_normal;
 533                 break;
 534         }
 535
 536         if (XFER_STATUS_RETRIES <= retries) {
 537                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 538                 buf[0] = CP2112_CANCEL_TRANSFER;
 539                 buf[1] = 0x01;
 540
 541                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 542                 if (ret < 0)
 543                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 544                                  ret);
 545
 546                 ret = -ETIMEDOUT;
 547                 goto power_normal;
 548         }
 549
 550         if (I2C_SMBUS_WRITE == read_write) {
 551                 ret = 0;
 552                 goto power_normal;
 553         }
 554
 555         if (I2C_SMBUS_BLOCK_DATA == size)
 556                 read_length = ret;
 557
 558         ret = cp2112_read(dev, buf, read_length);
 559         if (ret < 0)
 560                 goto power_normal;
 561         if (ret != read_length) {
 562                 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
 563                 ret = -EIO;
 564                 goto power_normal;
 565         }
 566
 567         switch (size) {
 568         case I2C_SMBUS_BYTE:
 569         case I2C_SMBUS_BYTE_DATA:
 570                 data->byte = buf[0];
 571                 break;
 572         case I2C_SMBUS_WORD_DATA:
 573                 data->word = be16_to_cpup((__be16 *)buf);
 574                 break;
 575         case I2C_SMBUS_BLOCK_DATA:
 576                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 577                         ret = -EPROTO;
 578                         goto power_normal;
 579                 }
 580
 581                 memcpy(data->block, buf, read_length);
 582                 break;
 583         }
 584
 585         ret = 0;
 586 power_normal:
 587         hid_hw_power(hdev, PM_HINT_NORMAL);
 588         hid_dbg(hdev, "transfer finished: %d\n", ret);
 589         return ret;
 590 }
 591
 592 static u32 cp2112_functionality(struct i2c_adapter *adap)
 593 {
 594         return I2C_FUNC_SMBUS_BYTE |
 595                 I2C_FUNC_SMBUS_BYTE_DATA |
 596                 I2C_FUNC_SMBUS_WORD_DATA |
 597                 I2C_FUNC_SMBUS_BLOCK_DATA |
 598                 I2C_FUNC_SMBUS_I2C_BLOCK |
 599                 I2C_FUNC_SMBUS_PROC_CALL |
 600                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 601 }
 602
 603 static const struct i2c_algorithm smbus_algorithm = {
 604         .smbus_xfer     = cp2112_xfer,
 605         .functionality  = cp2112_functionality,
 606 };
 607
 608 static int cp2112_get_usb_config(struct hid_device *hdev,
 609                                  struct cp2112_usb_config_report *cfg)
 610 {
 611         int ret;
 612
 613         ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
 614                              HID_FEATURE_REPORT);
 615         if (ret != sizeof(*cfg)) {
 616                 hid_err(hdev, "error reading usb config: %d\n", ret);
 617                 if (ret < 0)
 618                         return ret;
 619                 return -EIO;
 620         }
 621
 622         return 0;
 623 }
 624
 625 static int cp2112_set_usb_config(struct hid_device *hdev,
 626                                  struct cp2112_usb_config_report *cfg)
 627 {
 628         int ret;
 629
 630         BUG_ON(cfg->report != CP2112_USB_CONFIG);
 631
 632         ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
 633                                 HID_FEATURE_REPORT);
 634         if (ret != sizeof(*cfg)) {
 635                 hid_err(hdev, "error writing usb config: %d\n", ret);
 636                 if (ret < 0)
 637                         return ret;
 638                 return -EIO;
 639         }
 640
 641         return 0;
 642 }
 643
 644 static void chmod_sysfs_attrs(struct hid_device *hdev);
 645
 646 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
 647 static ssize_t name##_store(struct device *kdev, \
 648                             struct device_attribute *attr, const char *buf, \
 649                             size_t count) \
 650 { \
 651         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 652         struct cp2112_usb_config_report cfg; \
 653         int ret = cp2112_get_usb_config(hdev, &cfg); \
 654         if (ret) \
 655                 return ret; \
 656         store; \
 657         ret = cp2112_set_usb_config(hdev, &cfg); \
 658         if (ret) \
 659                 return ret; \
 660         chmod_sysfs_attrs(hdev); \
 661         return count; \
 662 } \
 663 static ssize_t name##_show(struct device *kdev, \
 664                            struct device_attribute *attr, char *buf) \
 665 { \
 666         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 667         struct cp2112_usb_config_report cfg; \
 668         int ret = cp2112_get_usb_config(hdev, &cfg); \
 669         if (ret) \
 670                 return ret; \
 671         return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
 672 } \
 673 static DEVICE_ATTR_RW(name);
 674
 675 CP2112_CONFIG_ATTR(vendor_id, ({
 676         u16 vid;
 677
 678         if (sscanf(buf, "%hi", &vid) != 1)
 679                 return -EINVAL;
 680
 681         cfg.vid = cpu_to_le16(vid);
 682         cfg.mask = 0x01;
 683 }), "0x%04x\n", le16_to_cpu(cfg.vid));
 684
 685 CP2112_CONFIG_ATTR(product_id, ({
 686         u16 pid;
 687
 688         if (sscanf(buf, "%hi", &pid) != 1)
 689                 return -EINVAL;
 690
 691         cfg.pid = cpu_to_le16(pid);
 692         cfg.mask = 0x02;
 693 }), "0x%04x\n", le16_to_cpu(cfg.pid));
 694
 695 CP2112_CONFIG_ATTR(max_power, ({
 696         int mA;
 697
 698         if (sscanf(buf, "%i", &mA) != 1)
 699                 return -EINVAL;
 700
 701         cfg.max_power = (mA + 1) / 2;
 702         cfg.mask = 0x04;
 703 }), "%u mA\n", cfg.max_power * 2);
 704
 705 CP2112_CONFIG_ATTR(power_mode, ({
 706         if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
 707                 return -EINVAL;
 708
 709         cfg.mask = 0x08;
 710 }), "%u\n", cfg.power_mode);
 711
 712 CP2112_CONFIG_ATTR(release_version, ({
 713         if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
 714             != 2)
 715                 return -EINVAL;
 716
 717         cfg.mask = 0x10;
 718 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
 719
 720 #undef CP2112_CONFIG_ATTR
 721
 722 struct cp2112_pstring_attribute {
 723         struct device_attribute attr;
 724         unsigned char report;
 725 };
 726
 727 static ssize_t pstr_store(struct device *kdev,
 728                           struct device_attribute *kattr, const char *buf,
 729                           size_t count)
 730 {
 731         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 732         struct cp2112_pstring_attribute *attr =
 733                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 734         struct cp2112_string_report report;
 735         int ret;
 736
 737         memset(&report, 0, sizeof(report));
 738
 739         ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 740                               report.string, ARRAY_SIZE(report.string));
 741         report.report = attr->report;
 742         report.length = ret * sizeof(report.string[0]) + 2;
 743         report.type = USB_DT_STRING;
 744
 745         ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
 746                                 HID_FEATURE_REPORT);
 747         if (ret != report.length + 1) {
 748                 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
 749                         ret);
 750                 if (ret < 0)
 751                         return ret;
 752                 return -EIO;
 753         }
 754
 755         chmod_sysfs_attrs(hdev);
 756         return count;
 757 }
 758
 759 static ssize_t pstr_show(struct device *kdev,
 760                          struct device_attribute *kattr, char *buf)
 761 {
 762         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 763         struct cp2112_pstring_attribute *attr =
 764                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 765         struct cp2112_string_report report;
 766         u8 length;
 767         int ret;
 768
 769         ret = cp2112_hid_get(hdev, attr->report, &report.report,
 770                              sizeof(report) - 1, HID_FEATURE_REPORT);
 771         if (ret < 3) {
 772                 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
 773                         ret);
 774                 if (ret < 0)
 775                         return ret;
 776                 return -EIO;
 777         }
 778
 779         if (report.length < 2) {
 780                 hid_err(hdev, "invalid %s string length: %d\n",
 781                         kattr->attr.name, report.length);
 782                 return -EIO;
 783         }
 784
 785         length = report.length > ret - 1 ? ret - 1 : report.length;
 786         length = (length - 2) / sizeof(report.string[0]);
 787         ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
 788                               PAGE_SIZE - 1);
 789         buf[ret++] = '\n';
 790         return ret;
 791 }
 792
 793 #define CP2112_PSTR_ATTR(name, _report) \
 794 static struct cp2112_pstring_attribute dev_attr_##name = { \
 795         .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
 796         .report = _report, \
 797 };
 798
 799 CP2112_PSTR_ATTR(manufacturer,  CP2112_MANUFACTURER_STRING);
 800 CP2112_PSTR_ATTR(product,       CP2112_PRODUCT_STRING);
 801 CP2112_PSTR_ATTR(serial,        CP2112_SERIAL_STRING);
 802
 803 #undef CP2112_PSTR_ATTR
 804
 805 static const struct attribute_group cp2112_attr_group = {
 806         .attrs = (struct attribute *[]){
 807                 &dev_attr_vendor_id.attr,
 808                 &dev_attr_product_id.attr,
 809                 &dev_attr_max_power.attr,
 810                 &dev_attr_power_mode.attr,
 811                 &dev_attr_release_version.attr,
 812                 &dev_attr_manufacturer.attr.attr,
 813                 &dev_attr_product.attr.attr,
 814                 &dev_attr_serial.attr.attr,
 815                 NULL
 816         }
 817 };
 818
 819 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
 820  * PROM have already been programmed. We do not depend on this preventing
 821  * writing to these attributes since the CP2112 will simply ignore writes to
 822  * already-programmed fields. This is why there is no sense in fixing this
 823  * racy behaviour.
 824  */
 825 static void chmod_sysfs_attrs(struct hid_device *hdev)
 826 {
 827         struct attribute **attr;
 828         u8 buf[2];
 829         int ret;
 830
 831         ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
 832                              HID_FEATURE_REPORT);
 833         if (ret != sizeof(buf)) {
 834                 hid_err(hdev, "error reading lock byte: %d\n", ret);
 835                 return;
 836         }
 837
 838         for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
 839                 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
 840                 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
 841                 if (ret < 0)
 842                         hid_err(hdev, "error chmoding sysfs file %s\n",
 843                                 (*attr)->name);
 844                 buf[1] >>= 1;
 845         }
 846 }
 847
 848 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 849 {
 850         struct cp2112_device *dev;
 851         u8 buf[3];
 852         struct cp2112_smbus_config_report config;
 853         int ret;
 854
 855         ret = hid_parse(hdev);
 856         if (ret) {
 857                 hid_err(hdev, "parse failed\n");
 858                 return ret;
 859         }
 860
 861         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 862         if (ret) {
 863                 hid_err(hdev, "hw start failed\n");
 864                 return ret;
 865         }
 866
 867         ret = hid_hw_open(hdev);
 868         if (ret) {
 869                 hid_err(hdev, "hw open failed\n");
 870                 goto err_hid_stop;
 871         }
 872
 873         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 874         if (ret < 0) {
 875                 hid_err(hdev, "power management error: %d\n", ret);
 876                 goto err_hid_close;
 877         }
 878
 879         ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
 880                              HID_FEATURE_REPORT);
 881         if (ret != sizeof(buf)) {
 882                 hid_err(hdev, "error requesting version\n");
 883                 if (ret >= 0)
 884                         ret = -EIO;
 885                 goto err_power_normal;
 886         }
 887
 888         hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
 889                  buf[1], buf[2]);
 890
 891         ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
 892                              sizeof(config), HID_FEATURE_REPORT);
 893         if (ret != sizeof(config)) {
 894                 hid_err(hdev, "error requesting SMBus config\n");
 895                 if (ret >= 0)
 896                         ret = -EIO;
 897                 goto err_power_normal;
 898         }
 899
 900         config.retry_time = cpu_to_be16(1);
 901
 902         ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
 903                                 HID_FEATURE_REPORT);
 904         if (ret != sizeof(config)) {
 905                 hid_err(hdev, "error setting SMBus config\n");
 906                 if (ret >= 0)
 907                         ret = -EIO;
 908                 goto err_power_normal;
 909         }
 910
 911         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 912         if (!dev) {
 913                 ret = -ENOMEM;
 914                 goto err_power_normal;
 915         }
 916
 917         hid_set_drvdata(hdev, (void *)dev);
 918         dev->hdev               = hdev;
 919         dev->adap.owner         = THIS_MODULE;
 920         dev->adap.class         = I2C_CLASS_HWMON;
 921         dev->adap.algo          = &smbus_algorithm;
 922         dev->adap.algo_data     = dev;
 923         dev->adap.dev.parent    = &hdev->dev;
 924         snprintf(dev->adap.name, sizeof(dev->adap.name),
 925                  "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
 926         init_waitqueue_head(&dev->wait);
 927
 928         hid_device_io_start(hdev);
 929         ret = i2c_add_adapter(&dev->adap);
 930         hid_device_io_stop(hdev);
 931
 932         if (ret) {
 933                 hid_err(hdev, "error registering i2c adapter\n");
 934                 goto err_free_dev;
 935         }
 936
 937         hid_dbg(hdev, "adapter registered\n");
 938
 939         dev->gc.label                   = "cp2112_gpio";
 940         dev->gc.direction_input         = cp2112_gpio_direction_input;
 941         dev->gc.direction_output        = cp2112_gpio_direction_output;
 942         dev->gc.set                     = cp2112_gpio_set;
 943         dev->gc.get                     = cp2112_gpio_get;
 944         dev->gc.base                    = -1;
 945         dev->gc.ngpio                   = 8;
 946         dev->gc.can_sleep               = 1;
 947         dev->gc.dev                     = &hdev->dev;
 948
 949         ret = gpiochip_add(&dev->gc);
 950         if (ret < 0) {
 951                 hid_err(hdev, "error registering gpio chip\n");
 952                 goto err_free_i2c;
 953         }
 954
 955         ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
 956         if (ret < 0) {
 957                 hid_err(hdev, "error creating sysfs attrs\n");
 958                 goto err_gpiochip_remove;
 959         }
 960
 961         chmod_sysfs_attrs(hdev);
 962         hid_hw_power(hdev, PM_HINT_NORMAL);
 963
 964         return ret;
 965
 966 err_gpiochip_remove:
 967         if (gpiochip_remove(&dev->gc) < 0)
 968                 hid_err(hdev, "error removing gpio chip\n");
 969 err_free_i2c:
 970         i2c_del_adapter(&dev->adap);
 971 err_free_dev:
 972         kfree(dev);
 973 err_power_normal:
 974         hid_hw_power(hdev, PM_HINT_NORMAL);
 975 err_hid_close:
 976         hid_hw_close(hdev);
 977 err_hid_stop:
 978         hid_hw_stop(hdev);
 979         return ret;
 980 }
 981
 982 static void cp2112_remove(struct hid_device *hdev)
 983 {
 984         struct cp2112_device *dev = hid_get_drvdata(hdev);
 985
 986         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
 987         if (gpiochip_remove(&dev->gc))
 988                 hid_err(hdev, "unable to remove gpio chip\n");
 989         i2c_del_adapter(&dev->adap);
 990         /* i2c_del_adapter has finished removing all i2c devices from our
 991          * adapter. Well behaved devices should no longer call our cp2112_xfer
 992          * and should have waited for any pending calls to finish. It has also
 993          * waited for device_unregister(&adap->dev) to complete. Therefore we
 994          * can safely free our struct cp2112_device.
 995          */
 996         hid_hw_close(hdev);
 997         hid_hw_stop(hdev);
 998         kfree(dev);
 999 }
1000
1001 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1002                             u8 *data, int size)
1003 {
1004         struct cp2112_device *dev = hid_get_drvdata(hdev);
1005         struct cp2112_xfer_status_report *xfer = (void *)data;
1006
1007         switch (data[0]) {
1008         case CP2112_TRANSFER_STATUS_RESPONSE:
1009                 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1010                         xfer->status0, xfer->status1,
1011                         be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1012
1013                 switch (xfer->status0) {
1014                 case STATUS0_IDLE:
1015                         dev->xfer_status = -EAGAIN;
1016                         break;
1017                 case STATUS0_BUSY:
1018                         dev->xfer_status = -EBUSY;
1019                         break;
1020                 case STATUS0_COMPLETE:
1021                         dev->xfer_status = be16_to_cpu(xfer->length);
1022                         break;
1023                 case STATUS0_ERROR:
1024                         switch (xfer->status1) {
1025                         case STATUS1_TIMEOUT_NACK:
1026                         case STATUS1_TIMEOUT_BUS:
1027                                 dev->xfer_status = -ETIMEDOUT;
1028                                 break;
1029                         default:
1030                                 dev->xfer_status = -EIO;
1031                                 break;
1032                         }
1033                         break;
1034                 default:
1035                         dev->xfer_status = -EINVAL;
1036                         break;
1037                 }
1038
1039                 atomic_set(&dev->xfer_avail, 1);
1040                 break;
1041         case CP2112_DATA_READ_RESPONSE:
1042                 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1043
1044                 dev->read_length = data[2];
1045                 if (dev->read_length > sizeof(dev->read_data))
1046                         dev->read_length = sizeof(dev->read_data);
1047
1048                 memcpy(dev->read_data, &data[3], dev->read_length);
1049                 atomic_set(&dev->read_avail, 1);
1050                 break;
1051         default:
1052                 hid_err(hdev, "unknown report\n");
1053
1054                 return 0;
1055         }
1056
1057         wake_up_interruptible(&dev->wait);
1058         return 1;
1059 }
1060
1061 static struct hid_driver cp2112_driver = {
1062         .name           = "cp2112",
1063         .id_table       = cp2112_devices,
1064         .probe          = cp2112_probe,
1065         .remove         = cp2112_remove,
1066         .raw_event      = cp2112_raw_event,
1067 };
1068
1069 module_hid_driver(cp2112_driver);
1070 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1071 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1072 MODULE_LICENSE("GPL");
1073