drivers/hid/hid-cp2112.c

   1 /*
   2  * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
   3  * Copyright (c) 2013,2014 Uplogix, Inc.
   4  * David Barksdale <dbarksdale@uplogix.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  */
  15
  16 /*
  17  * The Silicon Labs CP2112 chip is a USB HID device which provides an
  18  * SMBus controller for talking to slave devices and 8 GPIO pins. The
  19  * host communicates with the CP2112 via raw HID reports.
  20  *
  21  * Data Sheet:
  22  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
  23  * Programming Interface Specification:
  24  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
  25  */
  26
  27 #include <linux/gpio.h>
  28 #include <linux/hid.h>
  29 #include <linux/i2c.h>
  30 #include <linux/module.h>
  31 #include <linux/nls.h>
  32 #include <linux/usb/ch9.h>
  33 #include "hid-ids.h"
  34
  35 enum {
  36         CP2112_GPIO_CONFIG              = 0x02,
  37         CP2112_GPIO_GET                 = 0x03,
  38         CP2112_GPIO_SET                 = 0x04,
  39         CP2112_GET_VERSION_INFO         = 0x05,
  40         CP2112_SMBUS_CONFIG             = 0x06,
  41         CP2112_DATA_READ_REQUEST        = 0x10,
  42         CP2112_DATA_WRITE_READ_REQUEST  = 0x11,
  43         CP2112_DATA_READ_FORCE_SEND     = 0x12,
  44         CP2112_DATA_READ_RESPONSE       = 0x13,
  45         CP2112_DATA_WRITE_REQUEST       = 0x14,
  46         CP2112_TRANSFER_STATUS_REQUEST  = 0x15,
  47         CP2112_TRANSFER_STATUS_RESPONSE = 0x16,
  48         CP2112_CANCEL_TRANSFER          = 0x17,
  49         CP2112_LOCK_BYTE                = 0x20,
  50         CP2112_USB_CONFIG               = 0x21,
  51         CP2112_MANUFACTURER_STRING      = 0x22,
  52         CP2112_PRODUCT_STRING           = 0x23,
  53         CP2112_SERIAL_STRING            = 0x24,
  54 };
  55
  56 enum {
  57         STATUS0_IDLE            = 0x00,
  58         STATUS0_BUSY            = 0x01,
  59         STATUS0_COMPLETE        = 0x02,
  60         STATUS0_ERROR           = 0x03,
  61 };
  62
  63 enum {
  64         STATUS1_TIMEOUT_NACK            = 0x00,
  65         STATUS1_TIMEOUT_BUS             = 0x01,
  66         STATUS1_ARBITRATION_LOST        = 0x02,
  67         STATUS1_READ_INCOMPLETE         = 0x03,
  68         STATUS1_WRITE_INCOMPLETE        = 0x04,
  69         STATUS1_SUCCESS                 = 0x05,
  70 };
  71
  72 struct cp2112_smbus_config_report {
  73         u8 report;              /* CP2112_SMBUS_CONFIG */
  74         __be32 clock_speed;     /* Hz */
  75         u8 device_address;      /* Stored in the upper 7 bits */
  76         u8 auto_send_read;      /* 1 = enabled, 0 = disabled */
  77         __be16 write_timeout;   /* ms, 0 = no timeout */
  78         __be16 read_timeout;    /* ms, 0 = no timeout */
  79         u8 scl_low_timeout;     /* 1 = enabled, 0 = disabled */
  80         __be16 retry_time;      /* # of retries, 0 = no limit */
  81 } __packed;
  82
  83 struct cp2112_usb_config_report {
  84         u8 report;      /* CP2112_USB_CONFIG */
  85         __le16 vid;     /* Vendor ID */
  86         __le16 pid;     /* Product ID */
  87         u8 max_power;   /* Power requested in 2mA units */
  88         u8 power_mode;  /* 0x00 = bus powered
  89                            0x01 = self powered & regulator off
  90                            0x02 = self powered & regulator on */
  91         u8 release_major;
  92         u8 release_minor;
  93         u8 mask;        /* What fields to program */
  94 } __packed;
  95
  96 struct cp2112_read_req_report {
  97         u8 report;      /* CP2112_DATA_READ_REQUEST */
  98         u8 slave_address;
  99         __be16 length;
 100 } __packed;
 101
 102 struct cp2112_write_read_req_report {
 103         u8 report;      /* CP2112_DATA_WRITE_READ_REQUEST */
 104         u8 slave_address;
 105         __be16 length;
 106         u8 target_address_length;
 107         u8 target_address[16];
 108 } __packed;
 109
 110 struct cp2112_write_req_report {
 111         u8 report;      /* CP2112_DATA_WRITE_REQUEST */
 112         u8 slave_address;
 113         u8 length;
 114         u8 data[61];
 115 } __packed;
 116
 117 struct cp2112_force_read_report {
 118         u8 report;      /* CP2112_DATA_READ_FORCE_SEND */
 119         __be16 length;
 120 } __packed;
 121
 122 struct cp2112_xfer_status_report {
 123         u8 report;      /* CP2112_TRANSFER_STATUS_RESPONSE */
 124         u8 status0;     /* STATUS0_* */
 125         u8 status1;     /* STATUS1_* */
 126         __be16 retries;
 127         __be16 length;
 128 } __packed;
 129
 130 struct cp2112_string_report {
 131         u8 dummy;               /* force .string to be aligned */
 132         u8 report;              /* CP2112_*_STRING */
 133         u8 length;              /* length in bytes of everyting after .report */
 134         u8 type;                /* USB_DT_STRING */
 135         wchar_t string[30];     /* UTF16_LITTLE_ENDIAN string */
 136 } __packed;
 137
 138 /* Number of times to request transfer status before giving up waiting for a
 139    transfer to complete. This may need to be changed if SMBUS clock, retries,
 140    or read/write/scl_low timeout settings are changed. */
 141 static const int XFER_STATUS_RETRIES = 10;
 142
 143 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
 144    CP2112_TRANSFER_STATUS_RESPONSE. */
 145 static const int RESPONSE_TIMEOUT = 50;
 146
 147 static const struct hid_device_id cp2112_devices[] = {
 148         { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
 149         { }
 150 };
 151 MODULE_DEVICE_TABLE(hid, cp2112_devices);
 152
 153 struct cp2112_device {
 154         struct i2c_adapter adap;
 155         struct hid_device *hdev;
 156         wait_queue_head_t wait;
 157         u8 read_data[61];
 158         u8 read_length;
 159         int xfer_status;
 160         atomic_t read_avail;
 161         atomic_t xfer_avail;
 162         struct gpio_chip gc;
 163 };
 164
 165 static int gpio_push_pull = 0xFF;
 166 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
 167 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
 168
 169 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 170 {
 171         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 172                                                  gc);
 173         struct hid_device *hdev = dev->hdev;
 174         u8 buf[5];
 175         int ret;
 176
 177         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 178                                        sizeof(buf), HID_FEATURE_REPORT,
 179                                        HID_REQ_GET_REPORT);
 180         if (ret != sizeof(buf)) {
 181                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 182                 return ret;
 183         }
 184
 185         buf[1] &= ~(1 << offset);
 186         buf[2] = gpio_push_pull;
 187
 188         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
 189                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 190         if (ret < 0) {
 191                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 192                 return ret;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 199 {
 200         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 201                                                  gc);
 202         struct hid_device *hdev = dev->hdev;
 203         u8 buf[3];
 204         int ret;
 205
 206         buf[0] = CP2112_GPIO_SET;
 207         buf[1] = value ? 0xff : 0;
 208         buf[2] = 1 << offset;
 209
 210         ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
 211                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 212         if (ret < 0)
 213                 hid_err(hdev, "error setting GPIO values: %d\n", ret);
 214 }
 215
 216 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
 217 {
 218         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 219                                                  gc);
 220         struct hid_device *hdev = dev->hdev;
 221         u8 buf[2];
 222         int ret;
 223
 224         ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
 225                                        HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
 226         if (ret != sizeof(buf)) {
 227                 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
 228                 return ret;
 229         }
 230
 231         return (buf[1] >> offset) & 1;
 232 }
 233
 234 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
 235                                         unsigned offset, int value)
 236 {
 237         struct cp2112_device *dev = container_of(chip, struct cp2112_device,
 238                                                  gc);
 239         struct hid_device *hdev = dev->hdev;
 240         u8 buf[5];
 241         int ret;
 242
 243         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
 244                                        sizeof(buf), HID_FEATURE_REPORT,
 245                                        HID_REQ_GET_REPORT);
 246         if (ret != sizeof(buf)) {
 247                 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
 248                 return ret;
 249         }
 250
 251         buf[1] |= 1 << offset;
 252         buf[2] = gpio_push_pull;
 253
 254         ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
 255                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 256         if (ret < 0) {
 257                 hid_err(hdev, "error setting GPIO config: %d\n", ret);
 258                 return ret;
 259         }
 260
 261         /*
 262          * Set gpio value when output direction is already set,
 263          * as specified in AN495, Rev. 0.2, cpt. 4.4
 264          */
 265         cp2112_gpio_set(chip, offset, value);
 266
 267         return 0;
 268 }
 269
 270 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
 271                           u8 *data, size_t count, unsigned char report_type)
 272 {
 273         u8 *buf;
 274         int ret;
 275
 276         buf = kmalloc(count, GFP_KERNEL);
 277         if (!buf)
 278                 return -ENOMEM;
 279
 280         ret = hid_hw_raw_request(hdev, report_number, buf, count,
 281                                        report_type, HID_REQ_GET_REPORT);
 282         memcpy(data, buf, count);
 283         kfree(buf);
 284         return ret;
 285 }
 286
 287 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
 288                              unsigned char report_type)
 289 {
 290         u8 *buf;
 291         int ret;
 292
 293         buf = kmemdup(data, count, GFP_KERNEL);
 294         if (!buf)
 295                 return -ENOMEM;
 296
 297         if (report_type == HID_OUTPUT_REPORT)
 298                 ret = hid_hw_output_report(hdev, buf, count);
 299         else
 300                 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
 301                                 HID_REQ_SET_REPORT);
 302
 303         kfree(buf);
 304         return ret;
 305 }
 306
 307 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
 308 {
 309         int ret = 0;
 310
 311         /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
 312          * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
 313          * come in cp2112_raw_event or timeout. There will only be one of these
 314          * in flight at any one time. The timeout is extremely large and is a
 315          * last resort if the CP2112 has died. If we do timeout we don't expect
 316          * to receive the response which would cause data races, it's not like
 317          * we can do anything about it anyway.
 318          */
 319         ret = wait_event_interruptible_timeout(dev->wait,
 320                 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
 321         if (-ERESTARTSYS == ret)
 322                 return ret;
 323         if (!ret)
 324                 return -ETIMEDOUT;
 325
 326         atomic_set(avail, 0);
 327         return 0;
 328 }
 329
 330 static int cp2112_xfer_status(struct cp2112_device *dev)
 331 {
 332         struct hid_device *hdev = dev->hdev;
 333         u8 buf[2];
 334         int ret;
 335
 336         buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
 337         buf[1] = 0x01;
 338         atomic_set(&dev->xfer_avail, 0);
 339
 340         ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 341         if (ret < 0) {
 342                 hid_warn(hdev, "Error requesting status: %d\n", ret);
 343                 return ret;
 344         }
 345
 346         ret = cp2112_wait(dev, &dev->xfer_avail);
 347         if (ret)
 348                 return ret;
 349
 350         return dev->xfer_status;
 351 }
 352
 353 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 354 {
 355         struct hid_device *hdev = dev->hdev;
 356         struct cp2112_force_read_report report;
 357         int ret;
 358
 359         report.report = CP2112_DATA_READ_FORCE_SEND;
 360         report.length = cpu_to_be16(size);
 361
 362         atomic_set(&dev->read_avail, 0);
 363
 364         ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
 365                                 HID_OUTPUT_REPORT);
 366         if (ret < 0) {
 367                 hid_warn(hdev, "Error requesting data: %d\n", ret);
 368                 return ret;
 369         }
 370
 371         ret = cp2112_wait(dev, &dev->read_avail);
 372         if (ret)
 373                 return ret;
 374
 375         hid_dbg(hdev, "read %d of %zd bytes requested\n",
 376                 dev->read_length, size);
 377
 378         if (size > dev->read_length)
 379                 size = dev->read_length;
 380
 381         memcpy(data, dev->read_data, size);
 382         return dev->read_length;
 383 }
 384
 385 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
 386 {
 387         struct cp2112_read_req_report *report = buf;
 388
 389         if (length < 1 || length > 512)
 390                 return -EINVAL;
 391
 392         report->report = CP2112_DATA_READ_REQUEST;
 393         report->slave_address = slave_address << 1;
 394         report->length = cpu_to_be16(length);
 395         return sizeof(*report);
 396 }
 397
 398 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
 399                                  u8 command, u8 *data, u8 data_length)
 400 {
 401         struct cp2112_write_read_req_report *report = buf;
 402
 403         if (length < 1 || length > 512
 404             || data_length > sizeof(report->target_address) - 1)
 405                 return -EINVAL;
 406
 407         report->report = CP2112_DATA_WRITE_READ_REQUEST;
 408         report->slave_address = slave_address << 1;
 409         report->length = cpu_to_be16(length);
 410         report->target_address_length = data_length + 1;
 411         report->target_address[0] = command;
 412         memcpy(&report->target_address[1], data, data_length);
 413         return data_length + 6;
 414 }
 415
 416 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
 417                             u8 data_length)
 418 {
 419         struct cp2112_write_req_report *report = buf;
 420
 421         if (data_length > sizeof(report->data) - 1)
 422                 return -EINVAL;
 423
 424         report->report = CP2112_DATA_WRITE_REQUEST;
 425         report->slave_address = slave_address << 1;
 426         report->length = data_length + 1;
 427         report->data[0] = command;
 428         memcpy(&report->data[1], data, data_length);
 429         return data_length + 4;
 430 }
 431
 432 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
 433                                 u8 data_length)
 434 {
 435         struct cp2112_write_req_report *report = buf;
 436
 437         if (data_length > sizeof(report->data))
 438                 return -EINVAL;
 439
 440         report->report = CP2112_DATA_WRITE_REQUEST;
 441         report->slave_address = slave_address << 1;
 442         report->length = data_length;
 443         memcpy(report->data, data, data_length);
 444         return data_length + 3;
 445 }
 446
 447 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 448                            int num)
 449 {
 450         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 451         struct hid_device *hdev = dev->hdev;
 452         u8 buf[64];
 453         ssize_t count;
 454         unsigned int retries;
 455         int ret;
 456
 457         hid_dbg(hdev, "I2C %d messages\n", num);
 458
 459         if (num != 1) {
 460                 hid_err(hdev,
 461                         "Multi-message I2C transactions not supported\n");
 462                 return -EOPNOTSUPP;
 463         }
 464
 465         if (msgs->flags & I2C_M_RD)
 466                 count = cp2112_read_req(buf, msgs->addr, msgs->len);
 467         else
 468                 count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf,
 469                                              msgs->len);
 470
 471         if (count < 0)
 472                 return count;
 473
 474         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 475         if (ret < 0) {
 476                 hid_err(hdev, "power management error: %d\n", ret);
 477                 return ret;
 478         }
 479
 480         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 481         if (ret < 0) {
 482                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 483                 goto power_normal;
 484         }
 485
 486         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 487                 ret = cp2112_xfer_status(dev);
 488                 if (-EBUSY == ret)
 489                         continue;
 490                 if (ret < 0)
 491                         goto power_normal;
 492                 break;
 493         }
 494
 495         if (XFER_STATUS_RETRIES <= retries) {
 496                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 497                 buf[0] = CP2112_CANCEL_TRANSFER;
 498                 buf[1] = 0x01;
 499
 500                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 501                 if (ret < 0)
 502                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 503                                  ret);
 504
 505                 ret = -ETIMEDOUT;
 506                 goto power_normal;
 507         }
 508
 509         if (!(msgs->flags & I2C_M_RD))
 510                 goto finish;
 511
 512         ret = cp2112_read(dev, msgs->buf, msgs->len);
 513         if (ret < 0)
 514                 goto power_normal;
 515         if (ret != msgs->len) {
 516                 hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);
 517                 ret = -EIO;
 518                 goto power_normal;
 519         }
 520
 521 finish:
 522         /* return the number of transferred messages */
 523         ret = 1;
 524
 525 power_normal:
 526         hid_hw_power(hdev, PM_HINT_NORMAL);
 527         hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
 528         return ret;
 529 }
 530
 531 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 532                        unsigned short flags, char read_write, u8 command,
 533                        int size, union i2c_smbus_data *data)
 534 {
 535         struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
 536         struct hid_device *hdev = dev->hdev;
 537         u8 buf[64];
 538         __be16 word;
 539         ssize_t count;
 540         size_t read_length = 0;
 541         unsigned int retries;
 542         int ret;
 543
 544         hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
 545                 read_write == I2C_SMBUS_WRITE ? "write" : "read",
 546                 addr, flags, command, size);
 547
 548         switch (size) {
 549         case I2C_SMBUS_BYTE:
 550                 read_length = 1;
 551
 552                 if (I2C_SMBUS_READ == read_write)
 553                         count = cp2112_read_req(buf, addr, read_length);
 554                 else
 555                         count = cp2112_write_req(buf, addr, data->byte, NULL,
 556                                                  0);
 557                 break;
 558         case I2C_SMBUS_BYTE_DATA:
 559                 read_length = 1;
 560
 561                 if (I2C_SMBUS_READ == read_write)
 562                         count = cp2112_write_read_req(buf, addr, read_length,
 563                                                       command, NULL, 0);
 564                 else
 565                         count = cp2112_write_req(buf, addr, command,
 566                                                  &data->byte, 1);
 567                 break;
 568         case I2C_SMBUS_WORD_DATA:
 569                 read_length = 2;
 570                 word = cpu_to_be16(data->word);
 571
 572                 if (I2C_SMBUS_READ == read_write)
 573                         count = cp2112_write_read_req(buf, addr, read_length,
 574                                                       command, NULL, 0);
 575                 else
 576                         count = cp2112_write_req(buf, addr, command,
 577                                                  (u8 *)&word, 2);
 578                 break;
 579         case I2C_SMBUS_PROC_CALL:
 580                 size = I2C_SMBUS_WORD_DATA;
 581                 read_write = I2C_SMBUS_READ;
 582                 read_length = 2;
 583                 word = cpu_to_be16(data->word);
 584
 585                 count = cp2112_write_read_req(buf, addr, read_length, command,
 586                                               (u8 *)&word, 2);
 587                 break;
 588         case I2C_SMBUS_I2C_BLOCK_DATA:
 589                 size = I2C_SMBUS_BLOCK_DATA;
 590                 /* fallthrough */
 591         case I2C_SMBUS_BLOCK_DATA:
 592                 if (I2C_SMBUS_READ == read_write) {
 593                         count = cp2112_write_read_req(buf, addr,
 594                                                       I2C_SMBUS_BLOCK_MAX,
 595                                                       command, NULL, 0);
 596                 } else {
 597                         count = cp2112_write_req(buf, addr, command,
 598                                                  data->block,
 599                                                  data->block[0] + 1);
 600                 }
 601                 break;
 602         case I2C_SMBUS_BLOCK_PROC_CALL:
 603                 size = I2C_SMBUS_BLOCK_DATA;
 604                 read_write = I2C_SMBUS_READ;
 605
 606                 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
 607                                               command, data->block,
 608                                               data->block[0] + 1);
 609                 break;
 610         default:
 611                 hid_warn(hdev, "Unsupported transaction %d\n", size);
 612                 return -EOPNOTSUPP;
 613         }
 614
 615         if (count < 0)
 616                 return count;
 617
 618         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 619         if (ret < 0) {
 620                 hid_err(hdev, "power management error: %d\n", ret);
 621                 return ret;
 622         }
 623
 624         ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
 625         if (ret < 0) {
 626                 hid_warn(hdev, "Error starting transaction: %d\n", ret);
 627                 goto power_normal;
 628         }
 629
 630         for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
 631                 ret = cp2112_xfer_status(dev);
 632                 if (-EBUSY == ret)
 633                         continue;
 634                 if (ret < 0)
 635                         goto power_normal;
 636                 break;
 637         }
 638
 639         if (XFER_STATUS_RETRIES <= retries) {
 640                 hid_warn(hdev, "Transfer timed out, cancelling.\n");
 641                 buf[0] = CP2112_CANCEL_TRANSFER;
 642                 buf[1] = 0x01;
 643
 644                 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
 645                 if (ret < 0)
 646                         hid_warn(hdev, "Error cancelling transaction: %d\n",
 647                                  ret);
 648
 649                 ret = -ETIMEDOUT;
 650                 goto power_normal;
 651         }
 652
 653         if (I2C_SMBUS_WRITE == read_write) {
 654                 ret = 0;
 655                 goto power_normal;
 656         }
 657
 658         if (I2C_SMBUS_BLOCK_DATA == size)
 659                 read_length = ret;
 660
 661         ret = cp2112_read(dev, buf, read_length);
 662         if (ret < 0)
 663                 goto power_normal;
 664         if (ret != read_length) {
 665                 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
 666                 ret = -EIO;
 667                 goto power_normal;
 668         }
 669
 670         switch (size) {
 671         case I2C_SMBUS_BYTE:
 672         case I2C_SMBUS_BYTE_DATA:
 673                 data->byte = buf[0];
 674                 break;
 675         case I2C_SMBUS_WORD_DATA:
 676                 data->word = be16_to_cpup((__be16 *)buf);
 677                 break;
 678         case I2C_SMBUS_BLOCK_DATA:
 679                 if (read_length > I2C_SMBUS_BLOCK_MAX) {
 680                         ret = -EPROTO;
 681                         goto power_normal;
 682                 }
 683
 684                 memcpy(data->block, buf, read_length);
 685                 break;
 686         }
 687
 688         ret = 0;
 689 power_normal:
 690         hid_hw_power(hdev, PM_HINT_NORMAL);
 691         hid_dbg(hdev, "transfer finished: %d\n", ret);
 692         return ret;
 693 }
 694
 695 static u32 cp2112_functionality(struct i2c_adapter *adap)
 696 {
 697         return I2C_FUNC_I2C |
 698                 I2C_FUNC_SMBUS_BYTE |
 699                 I2C_FUNC_SMBUS_BYTE_DATA |
 700                 I2C_FUNC_SMBUS_WORD_DATA |
 701                 I2C_FUNC_SMBUS_BLOCK_DATA |
 702                 I2C_FUNC_SMBUS_I2C_BLOCK |
 703                 I2C_FUNC_SMBUS_PROC_CALL |
 704                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 705 }
 706
 707 static const struct i2c_algorithm smbus_algorithm = {
 708         .master_xfer    = cp2112_i2c_xfer,
 709         .smbus_xfer     = cp2112_xfer,
 710         .functionality  = cp2112_functionality,
 711 };
 712
 713 static int cp2112_get_usb_config(struct hid_device *hdev,
 714                                  struct cp2112_usb_config_report *cfg)
 715 {
 716         int ret;
 717
 718         ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
 719                              HID_FEATURE_REPORT);
 720         if (ret != sizeof(*cfg)) {
 721                 hid_err(hdev, "error reading usb config: %d\n", ret);
 722                 if (ret < 0)
 723                         return ret;
 724                 return -EIO;
 725         }
 726
 727         return 0;
 728 }
 729
 730 static int cp2112_set_usb_config(struct hid_device *hdev,
 731                                  struct cp2112_usb_config_report *cfg)
 732 {
 733         int ret;
 734
 735         BUG_ON(cfg->report != CP2112_USB_CONFIG);
 736
 737         ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
 738                                 HID_FEATURE_REPORT);
 739         if (ret != sizeof(*cfg)) {
 740                 hid_err(hdev, "error writing usb config: %d\n", ret);
 741                 if (ret < 0)
 742                         return ret;
 743                 return -EIO;
 744         }
 745
 746         return 0;
 747 }
 748
 749 static void chmod_sysfs_attrs(struct hid_device *hdev);
 750
 751 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
 752 static ssize_t name##_store(struct device *kdev, \
 753                             struct device_attribute *attr, const char *buf, \
 754                             size_t count) \
 755 { \
 756         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 757         struct cp2112_usb_config_report cfg; \
 758         int ret = cp2112_get_usb_config(hdev, &cfg); \
 759         if (ret) \
 760                 return ret; \
 761         store; \
 762         ret = cp2112_set_usb_config(hdev, &cfg); \
 763         if (ret) \
 764                 return ret; \
 765         chmod_sysfs_attrs(hdev); \
 766         return count; \
 767 } \
 768 static ssize_t name##_show(struct device *kdev, \
 769                            struct device_attribute *attr, char *buf) \
 770 { \
 771         struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
 772         struct cp2112_usb_config_report cfg; \
 773         int ret = cp2112_get_usb_config(hdev, &cfg); \
 774         if (ret) \
 775                 return ret; \
 776         return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
 777 } \
 778 static DEVICE_ATTR_RW(name);
 779
 780 CP2112_CONFIG_ATTR(vendor_id, ({
 781         u16 vid;
 782
 783         if (sscanf(buf, "%hi", &vid) != 1)
 784                 return -EINVAL;
 785
 786         cfg.vid = cpu_to_le16(vid);
 787         cfg.mask = 0x01;
 788 }), "0x%04x\n", le16_to_cpu(cfg.vid));
 789
 790 CP2112_CONFIG_ATTR(product_id, ({
 791         u16 pid;
 792
 793         if (sscanf(buf, "%hi", &pid) != 1)
 794                 return -EINVAL;
 795
 796         cfg.pid = cpu_to_le16(pid);
 797         cfg.mask = 0x02;
 798 }), "0x%04x\n", le16_to_cpu(cfg.pid));
 799
 800 CP2112_CONFIG_ATTR(max_power, ({
 801         int mA;
 802
 803         if (sscanf(buf, "%i", &mA) != 1)
 804                 return -EINVAL;
 805
 806         cfg.max_power = (mA + 1) / 2;
 807         cfg.mask = 0x04;
 808 }), "%u mA\n", cfg.max_power * 2);
 809
 810 CP2112_CONFIG_ATTR(power_mode, ({
 811         if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
 812                 return -EINVAL;
 813
 814         cfg.mask = 0x08;
 815 }), "%u\n", cfg.power_mode);
 816
 817 CP2112_CONFIG_ATTR(release_version, ({
 818         if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
 819             != 2)
 820                 return -EINVAL;
 821
 822         cfg.mask = 0x10;
 823 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
 824
 825 #undef CP2112_CONFIG_ATTR
 826
 827 struct cp2112_pstring_attribute {
 828         struct device_attribute attr;
 829         unsigned char report;
 830 };
 831
 832 static ssize_t pstr_store(struct device *kdev,
 833                           struct device_attribute *kattr, const char *buf,
 834                           size_t count)
 835 {
 836         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 837         struct cp2112_pstring_attribute *attr =
 838                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 839         struct cp2112_string_report report;
 840         int ret;
 841
 842         memset(&report, 0, sizeof(report));
 843
 844         ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 845                               report.string, ARRAY_SIZE(report.string));
 846         report.report = attr->report;
 847         report.length = ret * sizeof(report.string[0]) + 2;
 848         report.type = USB_DT_STRING;
 849
 850         ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
 851                                 HID_FEATURE_REPORT);
 852         if (ret != report.length + 1) {
 853                 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
 854                         ret);
 855                 if (ret < 0)
 856                         return ret;
 857                 return -EIO;
 858         }
 859
 860         chmod_sysfs_attrs(hdev);
 861         return count;
 862 }
 863
 864 static ssize_t pstr_show(struct device *kdev,
 865                          struct device_attribute *kattr, char *buf)
 866 {
 867         struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
 868         struct cp2112_pstring_attribute *attr =
 869                 container_of(kattr, struct cp2112_pstring_attribute, attr);
 870         struct cp2112_string_report report;
 871         u8 length;
 872         int ret;
 873
 874         ret = cp2112_hid_get(hdev, attr->report, &report.report,
 875                              sizeof(report) - 1, HID_FEATURE_REPORT);
 876         if (ret < 3) {
 877                 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
 878                         ret);
 879                 if (ret < 0)
 880                         return ret;
 881                 return -EIO;
 882         }
 883
 884         if (report.length < 2) {
 885                 hid_err(hdev, "invalid %s string length: %d\n",
 886                         kattr->attr.name, report.length);
 887                 return -EIO;
 888         }
 889
 890         length = report.length > ret - 1 ? ret - 1 : report.length;
 891         length = (length - 2) / sizeof(report.string[0]);
 892         ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
 893                               PAGE_SIZE - 1);
 894         buf[ret++] = '\n';
 895         return ret;
 896 }
 897
 898 #define CP2112_PSTR_ATTR(name, _report) \
 899 static struct cp2112_pstring_attribute dev_attr_##name = { \
 900         .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
 901         .report = _report, \
 902 };
 903
 904 CP2112_PSTR_ATTR(manufacturer,  CP2112_MANUFACTURER_STRING);
 905 CP2112_PSTR_ATTR(product,       CP2112_PRODUCT_STRING);
 906 CP2112_PSTR_ATTR(serial,        CP2112_SERIAL_STRING);
 907
 908 #undef CP2112_PSTR_ATTR
 909
 910 static const struct attribute_group cp2112_attr_group = {
 911         .attrs = (struct attribute *[]){
 912                 &dev_attr_vendor_id.attr,
 913                 &dev_attr_product_id.attr,
 914                 &dev_attr_max_power.attr,
 915                 &dev_attr_power_mode.attr,
 916                 &dev_attr_release_version.attr,
 917                 &dev_attr_manufacturer.attr.attr,
 918                 &dev_attr_product.attr.attr,
 919                 &dev_attr_serial.attr.attr,
 920                 NULL
 921         }
 922 };
 923
 924 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
 925  * PROM have already been programmed. We do not depend on this preventing
 926  * writing to these attributes since the CP2112 will simply ignore writes to
 927  * already-programmed fields. This is why there is no sense in fixing this
 928  * racy behaviour.
 929  */
 930 static void chmod_sysfs_attrs(struct hid_device *hdev)
 931 {
 932         struct attribute **attr;
 933         u8 buf[2];
 934         int ret;
 935
 936         ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
 937                              HID_FEATURE_REPORT);
 938         if (ret != sizeof(buf)) {
 939                 hid_err(hdev, "error reading lock byte: %d\n", ret);
 940                 return;
 941         }
 942
 943         for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
 944                 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
 945                 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
 946                 if (ret < 0)
 947                         hid_err(hdev, "error chmoding sysfs file %s\n",
 948                                 (*attr)->name);
 949                 buf[1] >>= 1;
 950         }
 951 }
 952
 953 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 954 {
 955         struct cp2112_device *dev;
 956         u8 buf[3];
 957         struct cp2112_smbus_config_report config;
 958         int ret;
 959
 960         ret = hid_parse(hdev);
 961         if (ret) {
 962                 hid_err(hdev, "parse failed\n");
 963                 return ret;
 964         }
 965
 966         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 967         if (ret) {
 968                 hid_err(hdev, "hw start failed\n");
 969                 return ret;
 970         }
 971
 972         ret = hid_hw_open(hdev);
 973         if (ret) {
 974                 hid_err(hdev, "hw open failed\n");
 975                 goto err_hid_stop;
 976         }
 977
 978         ret = hid_hw_power(hdev, PM_HINT_FULLON);
 979         if (ret < 0) {
 980                 hid_err(hdev, "power management error: %d\n", ret);
 981                 goto err_hid_close;
 982         }
 983
 984         ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
 985                              HID_FEATURE_REPORT);
 986         if (ret != sizeof(buf)) {
 987                 hid_err(hdev, "error requesting version\n");
 988                 if (ret >= 0)
 989                         ret = -EIO;
 990                 goto err_power_normal;
 991         }
 992
 993         hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
 994                  buf[1], buf[2]);
 995
 996         ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
 997                              sizeof(config), HID_FEATURE_REPORT);
 998         if (ret != sizeof(config)) {
 999                 hid_err(hdev, "error requesting SMBus config\n");
1000                 if (ret >= 0)
1001                         ret = -EIO;
1002                 goto err_power_normal;
1003         }
1004
1005         config.retry_time = cpu_to_be16(1);
1006
1007         ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1008                                 HID_FEATURE_REPORT);
1009         if (ret != sizeof(config)) {
1010                 hid_err(hdev, "error setting SMBus config\n");
1011                 if (ret >= 0)
1012                         ret = -EIO;
1013                 goto err_power_normal;
1014         }
1015
1016         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1017         if (!dev) {
1018                 ret = -ENOMEM;
1019                 goto err_power_normal;
1020         }
1021
1022         hid_set_drvdata(hdev, (void *)dev);
1023         dev->hdev               = hdev;
1024         dev->adap.owner         = THIS_MODULE;
1025         dev->adap.class         = I2C_CLASS_HWMON;
1026         dev->adap.algo          = &smbus_algorithm;
1027         dev->adap.algo_data     = dev;
1028         dev->adap.dev.parent    = &hdev->dev;
1029         snprintf(dev->adap.name, sizeof(dev->adap.name),
1030                  "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
1031         init_waitqueue_head(&dev->wait);
1032
1033         hid_device_io_start(hdev);
1034         ret = i2c_add_adapter(&dev->adap);
1035         hid_device_io_stop(hdev);
1036
1037         if (ret) {
1038                 hid_err(hdev, "error registering i2c adapter\n");
1039                 goto err_free_dev;
1040         }
1041
1042         hid_dbg(hdev, "adapter registered\n");
1043
1044         dev->gc.label                   = "cp2112_gpio";
1045         dev->gc.direction_input         = cp2112_gpio_direction_input;
1046         dev->gc.direction_output        = cp2112_gpio_direction_output;
1047         dev->gc.set                     = cp2112_gpio_set;
1048         dev->gc.get                     = cp2112_gpio_get;
1049         dev->gc.base                    = -1;
1050         dev->gc.ngpio                   = 8;
1051         dev->gc.can_sleep               = 1;
1052         dev->gc.dev                     = &hdev->dev;
1053
1054         ret = gpiochip_add(&dev->gc);
1055         if (ret < 0) {
1056                 hid_err(hdev, "error registering gpio chip\n");
1057                 goto err_free_i2c;
1058         }
1059
1060         ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1061         if (ret < 0) {
1062                 hid_err(hdev, "error creating sysfs attrs\n");
1063                 goto err_gpiochip_remove;
1064         }
1065
1066         chmod_sysfs_attrs(hdev);
1067         hid_hw_power(hdev, PM_HINT_NORMAL);
1068
1069         return ret;
1070
1071 err_gpiochip_remove:
1072         gpiochip_remove(&dev->gc);
1073 err_free_i2c:
1074         i2c_del_adapter(&dev->adap);
1075 err_free_dev:
1076         kfree(dev);
1077 err_power_normal:
1078         hid_hw_power(hdev, PM_HINT_NORMAL);
1079 err_hid_close:
1080         hid_hw_close(hdev);
1081 err_hid_stop:
1082         hid_hw_stop(hdev);
1083         return ret;
1084 }
1085
1086 static void cp2112_remove(struct hid_device *hdev)
1087 {
1088         struct cp2112_device *dev = hid_get_drvdata(hdev);
1089
1090         sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1091         gpiochip_remove(&dev->gc);
1092         i2c_del_adapter(&dev->adap);
1093         /* i2c_del_adapter has finished removing all i2c devices from our
1094          * adapter. Well behaved devices should no longer call our cp2112_xfer
1095          * and should have waited for any pending calls to finish. It has also
1096          * waited for device_unregister(&adap->dev) to complete. Therefore we
1097          * can safely free our struct cp2112_device.
1098          */
1099         hid_hw_close(hdev);
1100         hid_hw_stop(hdev);
1101         kfree(dev);
1102 }
1103
1104 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1105                             u8 *data, int size)
1106 {
1107         struct cp2112_device *dev = hid_get_drvdata(hdev);
1108         struct cp2112_xfer_status_report *xfer = (void *)data;
1109
1110         switch (data[0]) {
1111         case CP2112_TRANSFER_STATUS_RESPONSE:
1112                 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1113                         xfer->status0, xfer->status1,
1114                         be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1115
1116                 switch (xfer->status0) {
1117                 case STATUS0_IDLE:
1118                         dev->xfer_status = -EAGAIN;
1119                         break;
1120                 case STATUS0_BUSY:
1121                         dev->xfer_status = -EBUSY;
1122                         break;
1123                 case STATUS0_COMPLETE:
1124                         dev->xfer_status = be16_to_cpu(xfer->length);
1125                         break;
1126                 case STATUS0_ERROR:
1127                         switch (xfer->status1) {
1128                         case STATUS1_TIMEOUT_NACK:
1129                         case STATUS1_TIMEOUT_BUS:
1130                                 dev->xfer_status = -ETIMEDOUT;
1131                                 break;
1132                         default:
1133                                 dev->xfer_status = -EIO;
1134                                 break;
1135                         }
1136                         break;
1137                 default:
1138                         dev->xfer_status = -EINVAL;
1139                         break;
1140                 }
1141
1142                 atomic_set(&dev->xfer_avail, 1);
1143                 break;
1144         case CP2112_DATA_READ_RESPONSE:
1145                 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1146
1147                 dev->read_length = data[2];
1148                 if (dev->read_length > sizeof(dev->read_data))
1149                         dev->read_length = sizeof(dev->read_data);
1150
1151                 memcpy(dev->read_data, &data[3], dev->read_length);
1152                 atomic_set(&dev->read_avail, 1);
1153                 break;
1154         default:
1155                 hid_err(hdev, "unknown report\n");
1156
1157                 return 0;
1158         }
1159
1160         wake_up_interruptible(&dev->wait);
1161         return 1;
1162 }
1163
1164 static struct hid_driver cp2112_driver = {
1165         .name           = "cp2112",
1166         .id_table       = cp2112_devices,
1167         .probe          = cp2112_probe,
1168         .remove         = cp2112_remove,
1169         .raw_event      = cp2112_raw_event,
1170 };
1171
1172 module_hid_driver(cp2112_driver);
1173 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1174 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1175 MODULE_LICENSE("GPL");
1176