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 = hdev->hid_get_raw_report(hdev, CP2112_GPIO_CONFIG, buf,
 178                                        sizeof(buf), HID_FEATURE_REPORT);
 179         if (ret != sizeof(buf)) {
 180                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 181                 return ret;
 182         }
 183
 184         buf[1] &= ~(1 << offset);
 185         buf[2] = gpio_push_pull;
 186
 187         ret = hdev->hid_output_raw_report(hdev, buf, sizeof(buf),
 188                                           HID_FEATURE_REPORT);
 189         if (ret < 0) {
 190                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 191                 return ret;
 192         }
 193
 194         return 0;
 195 }
 196
 197 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 198 {
 199         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 200                                                  gc);
 201         struct hid_device *hdev = dev->hdev;
 202         u8 buf[3];
 203         int ret;
 204
 205         buf[0] = CP2112_GPIO_SET;
 206         buf[1] = value ? 0xff : 0;
 207         buf[2] = 1 << offset;
 208
 209         ret = hdev->hid_output_raw_report(hdev, buf, sizeof(buf),
 210                                           HID_FEATURE_REPORT);
 211         if (ret < 0)
 212                 hid_err(hdev, "error setting GPIO values: %d\n", ret);
 213 }
 214
 215 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
 216 {
 217         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 218                                                  gc);
 219         struct hid_device *hdev = dev->hdev;
 220         u8 buf[2];
 221         int ret;
 222
 223         ret = hdev->hid_get_raw_report(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
 224                                        HID_FEATURE_REPORT);
 225         if (ret != sizeof(buf)) {
 226                 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
 227                 return ret;
 228         }
 229
 230         return (buf[1] >> offset) & 1;
 231 }
 232
 233 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
 234                                         unsigned offset, int value)
 235 {
 236         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 237                                                  gc);
 238         struct hid_device *hdev = dev->hdev;
 239         u8 buf[5];
 240         int ret;
 241
 242         cp2112_gpio_set(chip, offset, value);
 243
 244         ret = hdev->hid_get_raw_report(hdev, CP2112_GPIO_CONFIG, buf,
 245                                        sizeof(buf), HID_FEATURE_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 = hdev->hid_output_raw_report(hdev, buf, sizeof(buf),
 255                                           HID_FEATURE_REPORT);
 256         if (ret < 0) {
 257                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 258                 return ret;
 259         }
 260
 261         return 0;
 262 }
 263
 264 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
 265                           u8 *data, size_t count, unsigned char report_type)
 266 {
 267         u8 *buf;
 268         int ret;
 269
 270         buf = kmalloc(count, GFP_KERNEL);
 271         if (!buf)
 272                 return -ENOMEM;
 273
 274         ret = hdev->hid_get_raw_report(hdev, report_number, buf, count,
 275                                        report_type);
 276         memcpy(data, buf, count);
 277         kfree(buf);
 278         return ret;
 279 }
 280
 281 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
 282                              unsigned char report_type)
 283 {
 284         u8 *buf;
 285         int ret;
 286
 287         buf = kmemdup(data, count, GFP_KERNEL);
 288         if (!buf)
 289                 return -ENOMEM;
 290
 291         ret = hdev->hid_output_raw_report(hdev, buf, count, report_type);
 292         kfree(buf);
 293         return ret;
 294 }
 295
 296 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
 297 {
 298         int ret = 0;
 299
 300         /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
 301          * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
 302          * come in cp2112_raw_event or timeout. There will only be one of these
 303          * in flight at any one time. The timeout is extremely large and is a
 304          * last resort if the CP2112 has died. If we do timeout we don't expect
 305          * to receive the response which would cause data races, it's not like
 306          * we can do anything about it anyway.
 307          */
 308         ret = wait_event_interruptible_timeout(dev->wait,
 309                 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
 310         if (-ERESTARTSYS == ret)
 311                 return ret;
 312         if (!ret)
 313                 return -ETIMEDOUT;
 314
 315         atomic_set(avail, 0);
 316         return 0;
 317 }
 318
 319 static int cp2112_xfer_status(struct cp2112_device *dev)
 320 {
 321         struct hid_device *hdev = dev->hdev;
 322         u8 buf[2];
 323         int ret;
 324
 325         buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
 326         buf[1] = 0x01;
 327         atomic_set(&dev->xfer_avail, 0);
 328
 329         ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 330         if (ret < 0) {
 331                 hid_warn(hdev, "Error requesting status: %d\n", ret);
 332                 return ret;
 333         }
 334
 335         ret = cp2112_wait(dev, &dev->xfer_avail);
 336         if (ret)
 337                 return ret;
 338
 339         return dev->xfer_status;
 340 }
 341
 342 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 343 {
 344         struct hid_device *hdev = dev->hdev;
 345         struct cp2112_force_read_report report;
 346         int ret;
 347
 348         report.report = CP2112_DATA_READ_FORCE_SEND;
 349         report.length = cpu_to_be16(size);
 350
 351         atomic_set(&dev->read_avail, 0);
 352
 353         ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
 354                                 HID_OUTPUT_REPORT);
 355         if (ret < 0) {
 356                 hid_warn(hdev, "Error requesting data: %d\n", ret);
 357                 return ret;
 358         }
 359
 360         ret = cp2112_wait(dev, &dev->read_avail);
 361         if (ret)
 362                 return ret;
 363
 364         hid_dbg(hdev, "read %d of %d bytes requested\n",
 365                 dev->read_length, size);
 366
 367         if (size > dev->read_length)
 368                 size = dev->read_length;
 369
 370         memcpy(data, dev->read_data, size);
 371         return dev->read_length;
 372 }
 373
 374 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
 375 {
 376         struct cp2112_read_req_report *report = buf;
 377
 378         if (length < 1 || length > 512)
 379                 return -EINVAL;
 380
 381         report->report = CP2112_DATA_READ_REQUEST;
 382         report->slave_address = slave_address << 1;
 383         report->length = cpu_to_be16(length);
 384         return sizeof(*report);
 385 }
 386
 387 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
 388                                  u8 command, u8 *data, u8 data_length)
 389 {
 390         struct cp2112_write_read_req_report *report = buf;
 391
 392         if (length < 1 || length > 512
 393             || data_length > sizeof(report->target_address) - 1)
 394                 return -EINVAL;
 395
 396         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 397         report->slave_address = slave_address << 1;
 398         report->length = cpu_to_be16(length);
 399         report->target_address_length = data_length + 1;
 400         report->target_address[0] = command;
 401         memcpy(&report->target_address[1], data, data_length);
 402         return data_length + 6;
 403 }
 404
 405 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
 406                             u8 data_length)
 407 {
 408         struct cp2112_write_req_report *report = buf;
 409
 410         if (data_length > sizeof(report->data) - 1)
 411                 return -EINVAL;
 412
 413         report->report = CP2112_DATA_WRITE_REQUEST;
 414         report->slave_address = slave_address << 1;
 415         report->length = data_length + 1;
 416         report->data[0] = command;
 417         memcpy(&report->data[1], data, data_length);
 418         return data_length + 4;
 419 }
 420
 421 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 422                        unsigned short flags, char read_write, u8 command,
 423                        int size, union i2c_smbus_data *data)
 424 {
 425         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 426         struct hid_device *hdev = dev->hdev;
 427         u8 buf[64];
 428         __be16 word;
 429         size_t count;
 430         size_t read_length = 0;
 431         unsigned int retries;
 432         int ret;
 433
 434         hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
 435                 read_write == I2C_SMBUS_WRITE ? "write" : "read",
 436                 addr, flags, command, size);
 437
 438         switch (size) {
 439         case I2C_SMBUS_BYTE:
 440                 read_length = 1;
 441
 442                 if (I2C_SMBUS_READ == read_write)
 443                         count = cp2112_read_req(buf, addr, read_length);
 444                 else
 445                         count = cp2112_write_req(buf, addr, data->byte, NULL,
 446                                                  0);
 447                 break;
 448         case I2C_SMBUS_BYTE_DATA:
 449                 read_length = 1;
 450
 451                 if (I2C_SMBUS_READ == read_write)
 452                         count = cp2112_write_read_req(buf, addr, read_length,
 453                                                       command, NULL, 0);
 454                 else
 455                         count = cp2112_write_req(buf, addr, command,
 456                                                  &data->byte, 1);
 457                 break;
 458         case I2C_SMBUS_WORD_DATA:
 459                 read_length = 2;
 460                 word = cpu_to_be16(data->word);
 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                                                  (u8 *)&word, 2);
 468                 break;
 469         case I2C_SMBUS_PROC_CALL:
 470                 size = I2C_SMBUS_WORD_DATA;
 471                 read_write = I2C_SMBUS_READ;
 472                 read_length = 2;
 473                 word = cpu_to_be16(data->word);
 474
 475                 count = cp2112_write_read_req(buf, addr, read_length, command,
 476                                               (u8 *)&word, 2);
 477                 break;
 478         case I2C_SMBUS_I2C_BLOCK_DATA:
 479                 size = I2C_SMBUS_BLOCK_DATA;
 480                 /* fallthrough */
 481         case I2C_SMBUS_BLOCK_DATA:
 482                 if (I2C_SMBUS_READ == read_write) {
 483                         count = cp2112_write_read_req(buf, addr,
 484                                                       I2C_SMBUS_BLOCK_MAX,
 485                                                       command, NULL, 0);
 486                 } else {
 487                         count = cp2112_write_req(buf, addr, command,
 488                                                  data->block,
 489                                                  data->block[0] + 1);
 490                 }
 491                 break;
 492         case I2C_SMBUS_BLOCK_PROC_CALL:
 493                 size = I2C_SMBUS_BLOCK_DATA;
 494                 read_write = I2C_SMBUS_READ;
 495
 496                 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
 497                                               command, data->block,
 498                                               data->block[0] + 1);
 499                 break;
 500         default:
 501                 hid_warn(hdev, "Unsupported transaction %d\n", size);
 502                 return -EOPNOTSUPP;
 503         }
 504
 505         if (count < 0)
 506                 return count;
 507
 508         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 509         if (ret < 0) {
 510                 hid_err(hdev, "power management error: %d\n", ret);
 511                 return ret;
 512         }
 513
 514         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 515         if (ret < 0) {
 516                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 517                 goto power_normal;
 518         }
 519
 520         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 521                 ret = cp2112_xfer_status(dev);
 522                 if (-EBUSY == ret)
 523                         continue;
 524                 if (ret < 0)
 525                         goto power_normal;
 526                 break;
 527         }
 528
 529         if (XFER_STATUS_RETRIES <= retries) {
 530                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 531                 buf[0] = CP2112_CANCEL_TRANSFER;
 532                 buf[1] = 0x01;
 533
 534                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 535                 if (ret < 0)
 536                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 537                                  ret);
 538
 539                 ret = -ETIMEDOUT;
 540                 goto power_normal;
 541         }
 542
 543         if (I2C_SMBUS_WRITE == read_write) {
 544                 ret = 0;
 545                 goto power_normal;
 546         }
 547
 548         if (I2C_SMBUS_BLOCK_DATA == size)
 549                 read_length = ret;
 550
 551         ret = cp2112_read(dev, buf, read_length);
 552         if (ret < 0)
 553                 goto power_normal;
 554         if (ret != read_length) {
 555                 hid_warn(hdev, "short read: %d < %d\n", ret, read_length);
 556                 ret = -EIO;
 557                 goto power_normal;
 558         }
 559
 560         switch (size) {
 561         case I2C_SMBUS_BYTE:
 562         case I2C_SMBUS_BYTE_DATA:
 563                 data->byte = buf[0];
 564                 break;
 565         case I2C_SMBUS_WORD_DATA:
 566                 data->word = be16_to_cpup((__be16 *)buf);
 567                 break;
 568         case I2C_SMBUS_BLOCK_DATA:
 569                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 570                         ret = -EPROTO;
 571                         goto power_normal;
 572                 }
 573
 574                 memcpy(data->block, buf, read_length);
 575                 break;
 576         }
 577
 578         ret = 0;
 579 power_normal:
 580         hid_hw_power(hdev, PM_HINT_NORMAL);
 581         hid_dbg(hdev, "transfer finished: %d\n", ret);
 582         return ret;
 583 }
 584
 585 static u32 cp2112_functionality(struct i2c_adapter *adap)
 586 {
 587         return I2C_FUNC_SMBUS_BYTE |
 588                 I2C_FUNC_SMBUS_BYTE_DATA |
 589                 I2C_FUNC_SMBUS_WORD_DATA |
 590                 I2C_FUNC_SMBUS_BLOCK_DATA |
 591                 I2C_FUNC_SMBUS_I2C_BLOCK |
 592                 I2C_FUNC_SMBUS_PROC_CALL |
 593                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 594 }
 595
 596 static const struct i2c_algorithm smbus_algorithm = {
 597         .smbus_xfer     = cp2112_xfer,
 598         .functionality  = cp2112_functionality,
 599 };
 600
 601 static int cp2112_get_usb_config(struct hid_device *hdev,
 602                                  struct cp2112_usb_config_report *cfg)
 603 {
 604         int ret;
 605
 606         ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
 607                              HID_FEATURE_REPORT);
 608         if (ret != sizeof(*cfg)) {
 609                 hid_err(hdev, "error reading usb config: %d\n", ret);
 610                 if (ret < 0)
 611                         return ret;
 612                 return -EIO;
 613         }
 614
 615         return 0;
 616 }
 617
 618 static int cp2112_set_usb_config(struct hid_device *hdev,
 619                                  struct cp2112_usb_config_report *cfg)
 620 {
 621         int ret;
 622
 623         BUG_ON(cfg->report != CP2112_USB_CONFIG);
 624
 625         ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
 626                                 HID_FEATURE_REPORT);
 627         if (ret != sizeof(*cfg)) {
 628                 hid_err(hdev, "error writing usb config: %d\n", ret);
 629                 if (ret < 0)
 630                         return ret;
 631                 return -EIO;
 632         }
 633
 634         return 0;
 635 }
 636
 637 static void chmod_sysfs_attrs(struct hid_device *hdev);
 638
 639 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
 640 static ssize_t name##_store(struct device *kdev, \
 641                             struct device_attribute *attr, const char *buf, \
 642                             size_t count) \
 643 { \
 644         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 645         struct cp2112_usb_config_report cfg; \
 646         int ret = cp2112_get_usb_config(hdev, &cfg); \
 647         if (ret) \
 648                 return ret; \
 649         store; \
 650         ret = cp2112_set_usb_config(hdev, &cfg); \
 651         if (ret) \
 652                 return ret; \
 653         chmod_sysfs_attrs(hdev); \
 654         return count; \
 655 } \
 656 static ssize_t name##_show(struct device *kdev, \
 657                            struct device_attribute *attr, char *buf) \
 658 { \
 659         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 660         struct cp2112_usb_config_report cfg; \
 661         int ret = cp2112_get_usb_config(hdev, &cfg); \
 662         if (ret) \
 663                 return ret; \
 664         return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
 665 } \
 666 static DEVICE_ATTR_RW(name);
 667
 668 CP2112_CONFIG_ATTR(vendor_id, ({
 669         u16 vid;
 670
 671         if (sscanf(buf, "%hi", &vid) != 1)
 672                 return -EINVAL;
 673
 674         cfg.vid = cpu_to_le16(vid);
 675         cfg.mask = 0x01;
 676 }), "0x%04x\n", le16_to_cpu(cfg.vid));
 677
 678 CP2112_CONFIG_ATTR(product_id, ({
 679         u16 pid;
 680
 681         if (sscanf(buf, "%hi", &pid) != 1)
 682                 return -EINVAL;
 683
 684         cfg.pid = cpu_to_le16(pid);
 685         cfg.mask = 0x02;
 686 }), "0x%04x\n", le16_to_cpu(cfg.pid));
 687
 688 CP2112_CONFIG_ATTR(max_power, ({
 689         int mA;
 690
 691         if (sscanf(buf, "%i", &mA) != 1)
 692                 return -EINVAL;
 693
 694         cfg.max_power = (mA + 1) / 2;
 695         cfg.mask = 0x04;
 696 }), "%u mA\n", cfg.max_power * 2);
 697
 698 CP2112_CONFIG_ATTR(power_mode, ({
 699         if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
 700                 return -EINVAL;
 701
 702         cfg.mask = 0x08;
 703 }), "%u\n", cfg.power_mode);
 704
 705 CP2112_CONFIG_ATTR(release_version, ({
 706         if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
 707             != 2)
 708                 return -EINVAL;
 709
 710         cfg.mask = 0x10;
 711 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
 712
 713 #undef CP2112_CONFIG_ATTR
 714
 715 struct cp2112_pstring_attribute {
 716         struct device_attribute attr;
 717         unsigned char report;
 718 };
 719
 720 static ssize_t pstr_store(struct device *kdev,
 721                           struct device_attribute *kattr, const char *buf,
 722                           size_t count)
 723 {
 724         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 725         struct cp2112_pstring_attribute *attr =
 726                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 727         struct cp2112_string_report report;
 728         int ret;
 729
 730         memset(&report, 0, sizeof(report));
 731
 732         ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 733                               report.string, ARRAY_SIZE(report.string));
 734         report.report = attr->report;
 735         report.length = ret * sizeof(report.string[0]) + 2;
 736         report.type = USB_DT_STRING;
 737
 738         ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
 739                                 HID_FEATURE_REPORT);
 740         if (ret != report.length + 1) {
 741                 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
 742                         ret);
 743                 if (ret < 0)
 744                         return ret;
 745                 return -EIO;
 746         }
 747
 748         chmod_sysfs_attrs(hdev);
 749         return count;
 750 }
 751
 752 static ssize_t pstr_show(struct device *kdev,
 753                          struct device_attribute *kattr, char *buf)
 754 {
 755         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 756         struct cp2112_pstring_attribute *attr =
 757                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 758         struct cp2112_string_report report;
 759         u8 length;
 760         int ret;
 761
 762         ret = cp2112_hid_get(hdev, attr->report, &report.report,
 763                              sizeof(report) - 1, HID_FEATURE_REPORT);
 764         if (ret < 3) {
 765                 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
 766                         ret);
 767                 if (ret < 0)
 768                         return ret;
 769                 return -EIO;
 770         }
 771
 772         if (report.length < 2) {
 773                 hid_err(hdev, "invalid %s string length: %d\n",
 774                         kattr->attr.name, report.length);
 775                 return -EIO;
 776         }
 777
 778         length = report.length > ret - 1 ? ret - 1 : report.length;
 779         length = (length - 2) / sizeof(report.string[0]);
 780         ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
 781                               PAGE_SIZE - 1);
 782         buf[ret++] = '\n';
 783         return ret;
 784 }
 785
 786 #define CP2112_PSTR_ATTR(name, _report) \
 787 static struct cp2112_pstring_attribute dev_attr_##name = { \
 788         .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
 789         .report = _report, \
 790 };
 791
 792 CP2112_PSTR_ATTR(manufacturer,  CP2112_MANUFACTURER_STRING);
 793 CP2112_PSTR_ATTR(product,       CP2112_PRODUCT_STRING);
 794 CP2112_PSTR_ATTR(serial,        CP2112_SERIAL_STRING);
 795
 796 #undef CP2112_PSTR_ATTR
 797
 798 static const struct attribute_group cp2112_attr_group = {
 799         .attrs = (struct attribute *[]){
 800                 &dev_attr_vendor_id.attr,
 801                 &dev_attr_product_id.attr,
 802                 &dev_attr_max_power.attr,
 803                 &dev_attr_power_mode.attr,
 804                 &dev_attr_release_version.attr,
 805                 &dev_attr_manufacturer.attr.attr,
 806                 &dev_attr_product.attr.attr,
 807                 &dev_attr_serial.attr.attr,
 808                 NULL
 809         }
 810 };
 811
 812 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
 813  * PROM have already been programmed. We do not depend on this preventing
 814  * writing to these attributes since the CP2112 will simply ignore writes to
 815  * already-programmed fields. This is why there is no sense in fixing this
 816  * racy behaviour.
 817  */
 818 static void chmod_sysfs_attrs(struct hid_device *hdev)
 819 {
 820         struct attribute **attr;
 821         u8 buf[2];
 822         int ret;
 823
 824         ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
 825                              HID_FEATURE_REPORT);
 826         if (ret != sizeof(buf)) {
 827                 hid_err(hdev, "error reading lock byte: %d\n", ret);
 828                 return;
 829         }
 830
 831         for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
 832                 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
 833                 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
 834                 if (ret < 0)
 835                         hid_err(hdev, "error chmoding sysfs file %s\n",
 836                                 (*attr)->name);
 837                 buf[1] >>= 1;
 838         }
 839 }
 840
 841 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 842 {
 843         struct cp2112_device *dev;
 844         u8 buf[3];
 845         struct cp2112_smbus_config_report config;
 846         int ret;
 847
 848         ret = hid_parse(hdev);
 849         if (ret) {
 850                 hid_err(hdev, "parse failed\n");
 851                 return ret;
 852         }
 853
 854         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 855         if (ret) {
 856                 hid_err(hdev, "hw start failed\n");
 857                 return ret;
 858         }
 859
 860         ret = hid_hw_open(hdev);
 861         if (ret) {
 862                 hid_err(hdev, "hw open failed\n");
 863                 goto err_hid_stop;
 864         }
 865
 866         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 867         if (ret < 0) {
 868                 hid_err(hdev, "power management error: %d\n", ret);
 869                 goto err_hid_close;
 870         }
 871
 872         ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
 873                              HID_FEATURE_REPORT);
 874         if (ret != sizeof(buf)) {
 875                 hid_err(hdev, "error requesting version\n");
 876                 if (ret >= 0)
 877                         ret = -EIO;
 878                 goto err_power_normal;
 879         }
 880
 881         hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
 882                  buf[1], buf[2]);
 883
 884         ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
 885                              sizeof(config), HID_FEATURE_REPORT);
 886         if (ret != sizeof(config)) {
 887                 hid_err(hdev, "error requesting SMBus config\n");
 888                 if (ret >= 0)
 889                         ret = -EIO;
 890                 goto err_power_normal;
 891         }
 892
 893         config.retry_time = cpu_to_be16(1);
 894
 895         ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
 896                                 HID_FEATURE_REPORT);
 897         if (ret != sizeof(config)) {
 898                 hid_err(hdev, "error setting SMBus config\n");
 899                 if (ret >= 0)
 900                         ret = -EIO;
 901                 goto err_power_normal;
 902         }
 903
 904         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 905         if (!dev) {
 906                 ret = -ENOMEM;
 907                 goto err_power_normal;
 908         }
 909
 910         hid_set_drvdata(hdev, (void *)dev);
 911         dev->hdev               = hdev;
 912         dev->adap.owner         = THIS_MODULE;
 913         dev->adap.class         = I2C_CLASS_HWMON;
 914         dev->adap.algo          = &smbus_algorithm;
 915         dev->adap.algo_data     = dev;
 916         dev->adap.dev.parent    = &hdev->dev;
 917         snprintf(dev->adap.name, sizeof(dev->adap.name),
 918                  "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
 919         init_waitqueue_head(&dev->wait);
 920
 921         hid_device_io_start(hdev);
 922         ret = i2c_add_adapter(&dev->adap);
 923         hid_device_io_stop(hdev);
 924
 925         if (ret) {
 926                 hid_err(hdev, "error registering i2c adapter\n");
 927                 goto err_free_dev;
 928         }
 929
 930         hid_dbg(hdev, "adapter registered\n");
 931
 932         dev->gc.label                   = "cp2112_gpio";
 933         dev->gc.direction_input         = cp2112_gpio_direction_input;
 934         dev->gc.direction_output        = cp2112_gpio_direction_output;
 935         dev->gc.set                     = cp2112_gpio_set;
 936         dev->gc.get                     = cp2112_gpio_get;
 937         dev->gc.base                    = -1;
 938         dev->gc.ngpio                   = 8;
 939         dev->gc.can_sleep               = 1;
 940         dev->gc.dev                     = &hdev->dev;
 941
 942         ret = gpiochip_add(&dev->gc);
 943         if (ret < 0) {
 944                 hid_err(hdev, "error registering gpio chip\n");
 945                 goto err_free_i2c;
 946         }
 947
 948         ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
 949         if (ret < 0) {
 950                 hid_err(hdev, "error creating sysfs attrs\n");
 951                 goto err_gpiochip_remove;
 952         }
 953
 954         chmod_sysfs_attrs(hdev);
 955         hid_hw_power(hdev, PM_HINT_NORMAL);
 956
 957         return ret;
 958
 959 err_gpiochip_remove:
 960         if (gpiochip_remove(&dev->gc) < 0)
 961                 hid_err(hdev, "error removing gpio chip\n");
 962 err_free_i2c:
 963         i2c_del_adapter(&dev->adap);
 964 err_free_dev:
 965         kfree(dev);
 966 err_power_normal:
 967         hid_hw_power(hdev, PM_HINT_NORMAL);
 968 err_hid_close:
 969         hid_hw_close(hdev);
 970 err_hid_stop:
 971         hid_hw_stop(hdev);
 972         return ret;
 973 }
 974
 975 static void cp2112_remove(struct hid_device *hdev)
 976 {
 977         struct cp2112_device *dev = hid_get_drvdata(hdev);
 978
 979         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
 980         if (gpiochip_remove(&dev->gc))
 981                 hid_err(hdev, "unable to remove gpio chip\n");
 982         i2c_del_adapter(&dev->adap);
 983         /* i2c_del_adapter has finished removing all i2c devices from our
 984          * adapter. Well behaved devices should no longer call our cp2112_xfer
 985          * and should have waited for any pending calls to finish. It has also
 986          * waited for device_unregister(&adap->dev) to complete. Therefore we
 987          * can safely free our struct cp2112_device.
 988          */
 989         hid_hw_close(hdev);
 990         hid_hw_stop(hdev);
 991         kfree(dev);
 992 }
 993
 994 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
 995                             u8 *data, int size)
 996 {
 997         struct cp2112_device *dev = hid_get_drvdata(hdev);
 998         struct cp2112_xfer_status_report *xfer = (void *)data;
 999
1000         switch (data[0]) {
1001         case CP2112_TRANSFER_STATUS_RESPONSE:
1002                 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1003                         xfer->status0, xfer->status1,
1004                         be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1005
1006                 switch (xfer->status0) {
1007                 case STATUS0_IDLE:
1008                         dev->xfer_status = -EAGAIN;
1009                         break;
1010                 case STATUS0_BUSY:
1011                         dev->xfer_status = -EBUSY;
1012                         break;
1013                 case STATUS0_COMPLETE:
1014                         dev->xfer_status = be16_to_cpu(xfer->length);
1015                         break;
1016                 case STATUS0_ERROR:
1017                         switch (xfer->status1) {
1018                         case STATUS1_TIMEOUT_NACK:
1019                         case STATUS1_TIMEOUT_BUS:
1020                                 dev->xfer_status = -ETIMEDOUT;
1021                                 break;
1022                         default:
1023                                 dev->xfer_status = -EIO;
1024                                 break;
1025                         }
1026                         break;
1027                 default:
1028                         dev->xfer_status = -EINVAL;
1029                         break;
1030                 }
1031
1032                 atomic_set(&dev->xfer_avail, 1);
1033                 break;
1034         case CP2112_DATA_READ_RESPONSE:
1035                 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1036
1037                 dev->read_length = data[2];
1038                 if (dev->read_length > sizeof(dev->read_data))
1039                         dev->read_length = sizeof(dev->read_data);
1040
1041                 memcpy(dev->read_data, &data[3], dev->read_length);
1042                 atomic_set(&dev->read_avail, 1);
1043                 break;
1044         default:
1045                 hid_err(hdev, "unknown report\n");
1046
1047                 return 0;
1048         }
1049
1050         wake_up_interruptible(&dev->wait);
1051         return 1;
1052 }
1053
1054 static struct hid_driver cp2112_driver = {
1055         .name           = "cp2112",
1056         .id_table       = cp2112_devices,
1057         .probe          = cp2112_probe,
1058         .remove         = cp2112_remove,
1059         .raw_event      = cp2112_raw_event,
1060 };
1061
1062 module_hid_driver(cp2112_driver);
1063 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1064 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1065 MODULE_LICENSE("GPL");
1066