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