drivers/staging/kpc2000/kpc2000_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * KPC2000 i2c driver
   4  *
   5  * Adapted i2c-i801.c for use with Kadoka hardware.
   6  *
   7  * Copyright (C) 1998 - 2002
   8  *      Frodo Looijaard <frodol@dds.nl>,
   9  *      Philip Edelbrock <phil@netroedge.com>,
  10  *      Mark D. Studebaker <mdsxyz123@yahoo.com>
  11  * Copyright (C) 2007 - 2012
  12  *      Jean Delvare <khali@linux-fr.org>
  13  * Copyright (C) 2010 Intel Corporation
  14  *      David Woodhouse <dwmw2@infradead.org>
  15  * Copyright (C) 2014-2018 Daktronics
  16  *      Matt Sickler <matt.sickler@daktronics.com>,
  17  *      Jordon Hofer <jordon.hofer@daktronics.com>
  18  */
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/io.h>
  23 #include <linux/io-64-nonatomic-lo-hi.h>
  24 #include <linux/export.h>
  25 #include <linux/slab.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/fs.h>
  28 #include <linux/delay.h>
  29 #include <linux/i2c.h>
  30 #include "kpc.h"
  31
  32 MODULE_LICENSE("GPL");
  33 MODULE_AUTHOR("Matt.Sickler@Daktronics.com");
  34
  35 struct i2c_device {
  36         unsigned long           smba;
  37         struct i2c_adapter      adapter;
  38         unsigned int            features;
  39 };
  40
  41 /*****************************
  42  *** Part 1 - i2c Handlers ***
  43  *****************************/
  44
  45 #define REG_SIZE 8
  46
  47 /* I801 SMBus address offsets */
  48 #define SMBHSTSTS(p)    ((0  * REG_SIZE) + (p)->smba)
  49 #define SMBHSTCNT(p)    ((2  * REG_SIZE) + (p)->smba)
  50 #define SMBHSTCMD(p)    ((3  * REG_SIZE) + (p)->smba)
  51 #define SMBHSTADD(p)    ((4  * REG_SIZE) + (p)->smba)
  52 #define SMBHSTDAT0(p)   ((5  * REG_SIZE) + (p)->smba)
  53 #define SMBHSTDAT1(p)   ((6  * REG_SIZE) + (p)->smba)
  54 #define SMBBLKDAT(p)    ((7  * REG_SIZE) + (p)->smba)
  55 #define SMBPEC(p)       ((8  * REG_SIZE) + (p)->smba)   /* ICH3 and later */
  56 #define SMBAUXSTS(p)    ((12 * REG_SIZE) + (p)->smba)   /* ICH4 and later */
  57 #define SMBAUXCTL(p)    ((13 * REG_SIZE) + (p)->smba)   /* ICH4 and later */
  58
  59 /* PCI Address Constants */
  60 #define SMBBAR      4
  61 #define SMBHSTCFG   0x040
  62
  63 /* Host configuration bits for SMBHSTCFG */
  64 #define SMBHSTCFG_HST_EN        1
  65 #define SMBHSTCFG_SMB_SMI_EN    2
  66 #define SMBHSTCFG_I2C_EN        4
  67
  68 /* Auxiliary control register bits, ICH4+ only */
  69 #define SMBAUXCTL_CRC       1
  70 #define SMBAUXCTL_E32B      2
  71
  72 /* kill bit for SMBHSTCNT */
  73 #define SMBHSTCNT_KILL      2
  74
  75 /* Other settings */
  76 #define MAX_RETRIES         400
  77 #define ENABLE_INT9         0       /* set to 0x01 to enable - untested */
  78
  79 /* I801 command constants */
  80 #define I801_QUICK              0x00
  81 #define I801_BYTE               0x04
  82 #define I801_BYTE_DATA          0x08
  83 #define I801_WORD_DATA          0x0C
  84 #define I801_PROC_CALL          0x10    /* unimplemented */
  85 #define I801_BLOCK_DATA         0x14
  86 #define I801_I2C_BLOCK_DATA     0x18    /* ICH5 and later */
  87 #define I801_BLOCK_LAST         0x34
  88 #define I801_I2C_BLOCK_LAST     0x38    /* ICH5 and later */
  89 #define I801_START              0x40
  90 #define I801_PEC_EN             0x80    /* ICH3 and later */
  91
  92 /* I801 Hosts Status register bits */
  93 #define SMBHSTSTS_BYTE_DONE     0x80
  94 #define SMBHSTSTS_INUSE_STS     0x40
  95 #define SMBHSTSTS_SMBALERT_STS  0x20
  96 #define SMBHSTSTS_FAILED        0x10
  97 #define SMBHSTSTS_BUS_ERR       0x08
  98 #define SMBHSTSTS_DEV_ERR       0x04
  99 #define SMBHSTSTS_INTR          0x02
 100 #define SMBHSTSTS_HOST_BUSY     0x01
 101
 102 #define STATUS_FLAGS        (SMBHSTSTS_BYTE_DONE | SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | SMBHSTSTS_DEV_ERR | SMBHSTSTS_INTR)
 103
 104 /* Older devices have their ID defined in <linux/pci_ids.h> */
 105 #define PCI_DEVICE_ID_INTEL_COUGARPOINT_SMBUS       0x1c22
 106 #define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS          0x1d22
 107 /* Patsburg also has three 'Integrated Device Function' SMBus controllers */
 108 #define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF0     0x1d70
 109 #define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF1     0x1d71
 110 #define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF2     0x1d72
 111 #define PCI_DEVICE_ID_INTEL_PANTHERPOINT_SMBUS      0x1e22
 112 #define PCI_DEVICE_ID_INTEL_DH89XXCC_SMBUS          0x2330
 113 #define PCI_DEVICE_ID_INTEL_5_3400_SERIES_SMBUS     0x3b30
 114 #define PCI_DEVICE_ID_INTEL_LYNXPOINT_SMBUS         0x8c22
 115 #define PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_SMBUS      0x9c22
 116
 117 #define FEATURE_SMBUS_PEC       BIT(0)
 118 #define FEATURE_BLOCK_BUFFER    BIT(1)
 119 #define FEATURE_BLOCK_PROC      BIT(2)
 120 #define FEATURE_I2C_BLOCK_READ  BIT(3)
 121 /* Not really a feature, but it's convenient to handle it as such */
 122 #define FEATURE_IDF             BIT(15)
 123
 124 // FIXME!
 125 #undef inb_p
 126 #define inb_p(a) readq((void __iomem *)a)
 127 #undef outb_p
 128 #define outb_p(d, a) writeq(d, (void __iomem *)a)
 129
 130 /* Make sure the SMBus host is ready to start transmitting.
 131  * Return 0 if it is, -EBUSY if it is not.
 132  */
 133 static int i801_check_pre(struct i2c_device *priv)
 134 {
 135         int status;
 136
 137         status = inb_p(SMBHSTSTS(priv));
 138         if (status & SMBHSTSTS_HOST_BUSY) {
 139                 dev_err(&priv->adapter.dev, "SMBus is busy, can't use it! (status=%x)\n", status);
 140                 return -EBUSY;
 141         }
 142
 143         status &= STATUS_FLAGS;
 144         if (status) {
 145                 //dev_dbg(&priv->adapter.dev, "Clearing status flags (%02x)\n", status);
 146                 outb_p(status, SMBHSTSTS(priv));
 147                 status = inb_p(SMBHSTSTS(priv)) & STATUS_FLAGS;
 148                 if (status) {
 149                         dev_err(&priv->adapter.dev, "Failed clearing status flags (%02x)\n", status);
 150                         return -EBUSY;
 151                 }
 152         }
 153         return 0;
 154 }
 155
 156 /* Convert the status register to an error code, and clear it. */
 157 static int i801_check_post(struct i2c_device *priv, int status, int timeout)
 158 {
 159         int result = 0;
 160
 161         /* If the SMBus is still busy, we give up */
 162         if (timeout) {
 163                 dev_err(&priv->adapter.dev, "Transaction timeout\n");
 164                 /* try to stop the current command */
 165                 dev_dbg(&priv->adapter.dev, "Terminating the current operation\n");
 166                 outb_p(inb_p(SMBHSTCNT(priv)) | SMBHSTCNT_KILL, SMBHSTCNT(priv));
 167                 usleep_range(1000, 2000);
 168                 outb_p(inb_p(SMBHSTCNT(priv)) & (~SMBHSTCNT_KILL), SMBHSTCNT(priv));
 169
 170                 /* Check if it worked */
 171                 status = inb_p(SMBHSTSTS(priv));
 172                 if ((status & SMBHSTSTS_HOST_BUSY) || !(status & SMBHSTSTS_FAILED))
 173                         dev_err(&priv->adapter.dev, "Failed terminating the transaction\n");
 174                 outb_p(STATUS_FLAGS, SMBHSTSTS(priv));
 175                 return -ETIMEDOUT;
 176         }
 177
 178         if (status & SMBHSTSTS_FAILED) {
 179                 result = -EIO;
 180                 dev_err(&priv->adapter.dev, "Transaction failed\n");
 181         }
 182         if (status & SMBHSTSTS_DEV_ERR) {
 183                 result = -ENXIO;
 184                 dev_dbg(&priv->adapter.dev, "No response\n");
 185         }
 186         if (status & SMBHSTSTS_BUS_ERR) {
 187                 result = -EAGAIN;
 188                 dev_dbg(&priv->adapter.dev, "Lost arbitration\n");
 189         }
 190
 191         if (result) {
 192                 /* Clear error flags */
 193                 outb_p(status & STATUS_FLAGS, SMBHSTSTS(priv));
 194                 status = inb_p(SMBHSTSTS(priv)) & STATUS_FLAGS;
 195                 if (status)
 196                         dev_warn(&priv->adapter.dev, "Failed clearing status flags at end of transaction (%02x)\n", status);
 197         }
 198
 199         return result;
 200 }
 201
 202 static int i801_transaction(struct i2c_device *priv, int xact)
 203 {
 204         int status;
 205         int result;
 206         int timeout = 0;
 207
 208         result = i801_check_pre(priv);
 209         if (result < 0)
 210                 return result;
 211         /* the current contents of SMBHSTCNT can be overwritten, since PEC,
 212          * INTREN, SMBSCMD are passed in xact
 213          */
 214         outb_p(xact | I801_START, SMBHSTCNT(priv));
 215
 216         /* We will always wait for a fraction of a second! */
 217         do {
 218                 usleep_range(250, 500);
 219                 status = inb_p(SMBHSTSTS(priv));
 220         } while ((status & SMBHSTSTS_HOST_BUSY) && (timeout++ < MAX_RETRIES));
 221
 222         result = i801_check_post(priv, status, timeout > MAX_RETRIES);
 223         if (result < 0)
 224                 return result;
 225
 226         outb_p(SMBHSTSTS_INTR, SMBHSTSTS(priv));
 227         return 0;
 228 }
 229
 230 /* wait for INTR bit as advised by Intel */
 231 static void i801_wait_hwpec(struct i2c_device *priv)
 232 {
 233         int timeout = 0;
 234         int status;
 235
 236         do {
 237                 usleep_range(250, 500);
 238                 status = inb_p(SMBHSTSTS(priv));
 239         } while ((!(status & SMBHSTSTS_INTR)) && (timeout++ < MAX_RETRIES));
 240
 241         if (timeout > MAX_RETRIES)
 242                 dev_dbg(&priv->adapter.dev, "PEC Timeout!\n");
 243
 244         outb_p(status, SMBHSTSTS(priv));
 245 }
 246
 247 static int i801_block_transaction_by_block(struct i2c_device *priv, union i2c_smbus_data *data, char read_write, int hwpec)
 248 {
 249         int i, len;
 250         int status;
 251
 252         inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
 253
 254         /* Use 32-byte buffer to process this transaction */
 255         if (read_write == I2C_SMBUS_WRITE) {
 256                 len = data->block[0];
 257                 outb_p(len, SMBHSTDAT0(priv));
 258                 for (i = 0; i < len; i++)
 259                         outb_p(data->block[i + 1], SMBBLKDAT(priv));
 260         }
 261
 262         status = i801_transaction(priv, I801_BLOCK_DATA | ENABLE_INT9 | I801_PEC_EN * hwpec);
 263         if (status)
 264                 return status;
 265
 266         if (read_write == I2C_SMBUS_READ) {
 267                 len = inb_p(SMBHSTDAT0(priv));
 268                 if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
 269                         return -EPROTO;
 270
 271                 data->block[0] = len;
 272                 for (i = 0; i < len; i++)
 273                         data->block[i + 1] = inb_p(SMBBLKDAT(priv));
 274         }
 275         return 0;
 276 }
 277
 278 static int i801_block_transaction_byte_by_byte(struct i2c_device *priv, union i2c_smbus_data *data, char read_write, int command, int hwpec)
 279 {
 280         int i, len;
 281         int smbcmd;
 282         int status;
 283         int result;
 284         int timeout;
 285
 286         result = i801_check_pre(priv);
 287         if (result < 0)
 288                 return result;
 289
 290         len = data->block[0];
 291
 292         if (read_write == I2C_SMBUS_WRITE) {
 293                 outb_p(len, SMBHSTDAT0(priv));
 294                 outb_p(data->block[1], SMBBLKDAT(priv));
 295         }
 296
 297         for (i = 1; i <= len; i++) {
 298                 if (i == len && read_write == I2C_SMBUS_READ) {
 299                         if (command == I2C_SMBUS_I2C_BLOCK_DATA)
 300                                 smbcmd = I801_I2C_BLOCK_LAST;
 301                         else
 302                                 smbcmd = I801_BLOCK_LAST;
 303                 } else {
 304                         if (command == I2C_SMBUS_I2C_BLOCK_DATA && read_write == I2C_SMBUS_READ)
 305                                 smbcmd = I801_I2C_BLOCK_DATA;
 306                         else
 307                                 smbcmd = I801_BLOCK_DATA;
 308                 }
 309                 outb_p(smbcmd | ENABLE_INT9, SMBHSTCNT(priv));
 310
 311                 if (i == 1)
 312                         outb_p(inb(SMBHSTCNT(priv)) | I801_START, SMBHSTCNT(priv));
 313                 /* We will always wait for a fraction of a second! */
 314                 timeout = 0;
 315                 do {
 316                         usleep_range(250, 500);
 317                         status = inb_p(SMBHSTSTS(priv));
 318                 } while ((!(status & SMBHSTSTS_BYTE_DONE)) && (timeout++ < MAX_RETRIES));
 319
 320                 result = i801_check_post(priv, status, timeout > MAX_RETRIES);
 321                 if (result < 0)
 322                         return result;
 323                 if (i == 1 && read_write == I2C_SMBUS_READ && command != I2C_SMBUS_I2C_BLOCK_DATA) {
 324                         len = inb_p(SMBHSTDAT0(priv));
 325                         if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) {
 326                                 dev_err(&priv->adapter.dev, "Illegal SMBus block read size %d\n", len);
 327                                 /* Recover */
 328                                 while (inb_p(SMBHSTSTS(priv)) & SMBHSTSTS_HOST_BUSY)
 329                                         outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv));
 330                                 outb_p(SMBHSTSTS_INTR, SMBHSTSTS(priv));
 331                                 return -EPROTO;
 332                         }
 333                         data->block[0] = len;
 334                 }
 335
 336                 /* Retrieve/store value in SMBBLKDAT */
 337                 if (read_write == I2C_SMBUS_READ)
 338                         data->block[i] = inb_p(SMBBLKDAT(priv));
 339                 if (read_write == I2C_SMBUS_WRITE && i + 1 <= len)
 340                         outb_p(data->block[i + 1], SMBBLKDAT(priv));
 341                 /* signals SMBBLKDAT ready */
 342                 outb_p(SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INTR, SMBHSTSTS(priv));
 343         }
 344
 345         return 0;
 346 }
 347
 348 static int i801_set_block_buffer_mode(struct i2c_device *priv)
 349 {
 350         outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv));
 351         if ((inb_p(SMBAUXCTL(priv)) & SMBAUXCTL_E32B) == 0)
 352                 return -EIO;
 353         return 0;
 354 }
 355
 356 /* Block transaction function */
 357 static int i801_block_transaction(struct i2c_device *priv, union i2c_smbus_data *data, char read_write, int command, int hwpec)
 358 {
 359         int result = 0;
 360         //unsigned char hostc;
 361
 362         if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
 363                 if (read_write == I2C_SMBUS_WRITE) {
 364                         /* set I2C_EN bit in configuration register */
 365                         //TODO: Figure out the right thing to do here...
 366                         //pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &hostc);
 367                         //pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc | SMBHSTCFG_I2C_EN);
 368                 } else if (!(priv->features & FEATURE_I2C_BLOCK_READ)) {
 369                         dev_err(&priv->adapter.dev, "I2C block read is unsupported!\n");
 370                         return -EOPNOTSUPP;
 371                 }
 372         }
 373
 374         if (read_write == I2C_SMBUS_WRITE || command == I2C_SMBUS_I2C_BLOCK_DATA) {
 375                 if (data->block[0] < 1)
 376                         data->block[0] = 1;
 377                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 378                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 379         } else {
 380                 data->block[0] = 32;    /* max for SMBus block reads */
 381         }
 382
 383         /* Experience has shown that the block buffer can only be used for
 384          * SMBus (not I2C) block transactions, even though the datasheet
 385          * doesn't mention this limitation.
 386          */
 387         if ((priv->features & FEATURE_BLOCK_BUFFER) && command != I2C_SMBUS_I2C_BLOCK_DATA && i801_set_block_buffer_mode(priv) == 0)
 388                 result = i801_block_transaction_by_block(priv, data, read_write, hwpec);
 389         else
 390                 result = i801_block_transaction_byte_by_byte(priv, data, read_write, command, hwpec);
 391         if (result == 0 && hwpec)
 392                 i801_wait_hwpec(priv);
 393         if (command == I2C_SMBUS_I2C_BLOCK_DATA && read_write == I2C_SMBUS_WRITE) {
 394                 /* restore saved configuration register value */
 395                 //TODO: Figure out the right thing to do here...
 396                 //pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc);
 397         }
 398         return result;
 399 }
 400
 401 /* Return negative errno on error. */
 402 static s32 i801_access(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data)
 403 {
 404         int hwpec;
 405         int block = 0;
 406         int ret, xact = 0;
 407         struct i2c_device *priv = i2c_get_adapdata(adap);
 408
 409         hwpec = (priv->features & FEATURE_SMBUS_PEC) && (flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA;
 410
 411         switch (size) {
 412         case I2C_SMBUS_QUICK:
 413                 dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_QUICK\n");
 414                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
 415                 xact = I801_QUICK;
 416                 break;
 417         case I2C_SMBUS_BYTE:
 418                 dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_BYTE\n");
 419
 420                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
 421                 if (read_write == I2C_SMBUS_WRITE)
 422                         outb_p(command, SMBHSTCMD(priv));
 423                 xact = I801_BYTE;
 424                 break;
 425         case I2C_SMBUS_BYTE_DATA:
 426                 dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_BYTE_DATA\n");
 427                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
 428                 outb_p(command, SMBHSTCMD(priv));
 429                 if (read_write == I2C_SMBUS_WRITE)
 430                         outb_p(data->byte, SMBHSTDAT0(priv));
 431                 xact = I801_BYTE_DATA;
 432                 break;
 433         case I2C_SMBUS_WORD_DATA:
 434                 dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_WORD_DATA\n");
 435                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
 436                 outb_p(command, SMBHSTCMD(priv));
 437                 if (read_write == I2C_SMBUS_WRITE) {
 438                         outb_p(data->word & 0xff, SMBHSTDAT0(priv));
 439                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
 440                 }
 441                 xact = I801_WORD_DATA;
 442                 break;
 443         case I2C_SMBUS_BLOCK_DATA:
 444                 dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_BLOCK_DATA\n");
 445                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
 446                 outb_p(command, SMBHSTCMD(priv));
 447                 block = 1;
 448                 break;
 449         case I2C_SMBUS_I2C_BLOCK_DATA:
 450                 dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_I2C_BLOCK_DATA\n");
 451                 /* NB: page 240 of ICH5 datasheet shows that the R/#W
 452                  * bit should be cleared here, even when reading
 453                  */
 454                 outb_p((addr & 0x7f) << 1, SMBHSTADD(priv));
 455                 if (read_write == I2C_SMBUS_READ) {
 456                         /* NB: page 240 of ICH5 datasheet also shows
 457                          * that DATA1 is the cmd field when reading
 458                          */
 459                         outb_p(command, SMBHSTDAT1(priv));
 460                 } else {
 461                         outb_p(command, SMBHSTCMD(priv));
 462                 }
 463                 block = 1;
 464                 break;
 465         default:
 466                 dev_dbg(&priv->adapter.dev, "  [acc] Unsupported transaction %d\n", size);
 467                 return -EOPNOTSUPP;
 468         }
 469
 470         if (hwpec) { /* enable/disable hardware PEC */
 471                 dev_dbg(&priv->adapter.dev, "  [acc] hwpec: yes\n");
 472                 outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_CRC, SMBAUXCTL(priv));
 473         } else {
 474                 dev_dbg(&priv->adapter.dev, "  [acc] hwpec: no\n");
 475                 outb_p(inb_p(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC), SMBAUXCTL(priv));
 476         }
 477
 478         if (block) {
 479                 //ret = 0;
 480                 dev_dbg(&priv->adapter.dev, "  [acc] block: yes\n");
 481                 ret = i801_block_transaction(priv, data, read_write, size, hwpec);
 482         } else {
 483                 dev_dbg(&priv->adapter.dev, "  [acc] block: no\n");
 484                 ret = i801_transaction(priv, xact | ENABLE_INT9);
 485         }
 486
 487         /* Some BIOSes don't like it when PEC is enabled at reboot or resume
 488          * time, so we forcibly disable it after every transaction. Turn off
 489          * E32B for the same reason.
 490          */
 491         if (hwpec || block) {
 492                 dev_dbg(&priv->adapter.dev, "  [acc] hwpec || block\n");
 493                 outb_p(inb_p(SMBAUXCTL(priv)) & ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));
 494         }
 495         if (block) {
 496                 dev_dbg(&priv->adapter.dev, "  [acc] block\n");
 497                 return ret;
 498         }
 499         if (ret) {
 500                 dev_dbg(&priv->adapter.dev, "  [acc] ret %d\n", ret);
 501                 return ret;
 502         }
 503         if ((read_write == I2C_SMBUS_WRITE) || (xact == I801_QUICK)) {
 504                 dev_dbg(&priv->adapter.dev, "  [acc] I2C_SMBUS_WRITE || I801_QUICK  -> ret 0\n");
 505                 return 0;
 506         }
 507
 508         switch (xact & 0x7f) {
 509         case I801_BYTE:  /* Result put in SMBHSTDAT0 */
 510         case I801_BYTE_DATA:
 511                 dev_dbg(&priv->adapter.dev, "  [acc] I801_BYTE or I801_BYTE_DATA\n");
 512                 data->byte = inb_p(SMBHSTDAT0(priv));
 513                 break;
 514         case I801_WORD_DATA:
 515                 dev_dbg(&priv->adapter.dev, "  [acc] I801_WORD_DATA\n");
 516                 data->word = inb_p(SMBHSTDAT0(priv)) + (inb_p(SMBHSTDAT1(priv)) << 8);
 517                 break;
 518         }
 519         return 0;
 520 }
 521
 522 static u32 i801_func(struct i2c_adapter *adapter)
 523 {
 524         struct i2c_device *priv = i2c_get_adapdata(adapter);
 525
 526         /* original settings
 527          * u32 f = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 528          * I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 529          * I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
 530          * ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
 531          * ((priv->features & FEATURE_I2C_BLOCK_READ) ?
 532          * I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
 533          */
 534
 535         // http://lxr.free-electrons.com/source/include/uapi/linux/i2c.h#L85
 536
 537         u32 f =
 538                 I2C_FUNC_I2C                     | /* 0x00000001 (I enabled this one) */
 539                 !I2C_FUNC_10BIT_ADDR             | /* 0x00000002 */
 540                 !I2C_FUNC_PROTOCOL_MANGLING      | /* 0x00000004 */
 541                 ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) | /* 0x00000008 */
 542                 !I2C_FUNC_SMBUS_BLOCK_PROC_CALL  | /* 0x00008000 */
 543                 I2C_FUNC_SMBUS_QUICK             | /* 0x00010000 */
 544                 !I2C_FUNC_SMBUS_READ_BYTE        | /* 0x00020000 */
 545                 !I2C_FUNC_SMBUS_WRITE_BYTE       | /* 0x00040000 */
 546                 !I2C_FUNC_SMBUS_READ_BYTE_DATA   | /* 0x00080000 */
 547                 !I2C_FUNC_SMBUS_WRITE_BYTE_DATA  | /* 0x00100000 */
 548                 !I2C_FUNC_SMBUS_READ_WORD_DATA   | /* 0x00200000 */
 549                 !I2C_FUNC_SMBUS_WRITE_WORD_DATA  | /* 0x00400000 */
 550                 !I2C_FUNC_SMBUS_PROC_CALL        | /* 0x00800000 */
 551                 !I2C_FUNC_SMBUS_READ_BLOCK_DATA  | /* 0x01000000 */
 552                 !I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | /* 0x02000000 */
 553                 ((priv->features & FEATURE_I2C_BLOCK_READ) ? I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) | /* 0x04000000 */
 554                 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK   | /* 0x08000000 */
 555
 556                 I2C_FUNC_SMBUS_BYTE              | /* _READ_BYTE  _WRITE_BYTE */
 557                 I2C_FUNC_SMBUS_BYTE_DATA         | /* _READ_BYTE_DATA  _WRITE_BYTE_DATA */
 558                 I2C_FUNC_SMBUS_WORD_DATA         | /* _READ_WORD_DATA  _WRITE_WORD_DATA */
 559                 I2C_FUNC_SMBUS_BLOCK_DATA        | /* _READ_BLOCK_DATA  _WRITE_BLOCK_DATA */
 560                 !I2C_FUNC_SMBUS_I2C_BLOCK        | /* _READ_I2C_BLOCK  _WRITE_I2C_BLOCK */
 561                 !I2C_FUNC_SMBUS_EMUL;              /* _QUICK  _BYTE  _BYTE_DATA  _WORD_DATA  _PROC_CALL  _WRITE_BLOCK_DATA  _I2C_BLOCK _PEC */
 562         return f;
 563 }
 564
 565 static const struct i2c_algorithm smbus_algorithm = {
 566         .smbus_xfer     = i801_access,
 567         .functionality  = i801_func,
 568 };
 569
 570 /********************************
 571  *** Part 2 - Driver Handlers ***
 572  ********************************/
 573 static int pi2c_probe(struct platform_device *pldev)
 574 {
 575         int err;
 576         struct i2c_device *priv;
 577         struct resource *res;
 578
 579         priv = devm_kzalloc(&pldev->dev, sizeof(*priv), GFP_KERNEL);
 580         if (!priv)
 581                 return -ENOMEM;
 582
 583         i2c_set_adapdata(&priv->adapter, priv);
 584         priv->adapter.owner = THIS_MODULE;
 585         priv->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 586         priv->adapter.algo = &smbus_algorithm;
 587
 588         res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
 589         if (!res)
 590                 return -ENXIO;
 591
 592         priv->smba = (unsigned long)devm_ioremap_nocache(&pldev->dev,
 593                                                          res->start,
 594                                                          resource_size(res));
 595         if (!priv->smba)
 596                 return -ENOMEM;
 597
 598         platform_set_drvdata(pldev, priv);
 599
 600         priv->features |= FEATURE_IDF;
 601         priv->features |= FEATURE_I2C_BLOCK_READ;
 602         priv->features |= FEATURE_SMBUS_PEC;
 603         priv->features |= FEATURE_BLOCK_BUFFER;
 604
 605         //init_MUTEX(&lddata->sem);
 606
 607         /* set up the sysfs linkage to our parent device */
 608         priv->adapter.dev.parent = &pldev->dev;
 609
 610         /* Retry up to 3 times on lost arbitration */
 611         priv->adapter.retries = 3;
 612
 613         //snprintf(priv->adapter.name, sizeof(priv->adapter.name), "Fake SMBus I801 adapter at %04lx", priv->smba);
 614         snprintf(priv->adapter.name, sizeof(priv->adapter.name), "Fake SMBus I801 adapter");
 615
 616         err = i2c_add_adapter(&priv->adapter);
 617         if (err) {
 618                 dev_err(&priv->adapter.dev, "Failed to add SMBus adapter\n");
 619                 return err;
 620         }
 621
 622         return 0;
 623 }
 624
 625 static int pi2c_remove(struct platform_device *pldev)
 626 {
 627         struct i2c_device *lddev;
 628
 629         lddev = (struct i2c_device *)platform_get_drvdata(pldev);
 630
 631         i2c_del_adapter(&lddev->adapter);
 632
 633         //TODO: Figure out the right thing to do here...
 634         //pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
 635         //pci_release_region(dev, SMBBAR);
 636         //pci_set_drvdata(dev, NULL);
 637
 638         //cdev_del(&lddev->cdev);
 639
 640         return 0;
 641 }
 642
 643 static struct platform_driver i2c_plat_driver_i = {
 644         .probe      = pi2c_probe,
 645         .remove     = pi2c_remove,
 646         .driver     = {
 647                 .name   = KP_DRIVER_NAME_I2C,
 648         },
 649 };
 650
 651 module_platform_driver(i2c_plat_driver_i);