root/drivers/i2c/busses/i2c-ali15x3.c

DEFINITIONS

1. ali15x3_setup
2. ali15x3_transaction
3. ali15x3_access
4. ali15x3_func
5. ali15x3_probe
6. ali15x3_remove

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3     Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
   4     Philip Edelbrock <phil@netroedge.com> and
   5     Mark D. Studebaker <mdsxyz123@yahoo.com>
   6 
   7 */
   8 
   9 /*
  10     This is the driver for the SMB Host controller on
  11     Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
  12 
  13     The M1543C is a South bridge for desktop systems.
  14     The M1533 is a South bridge for portable systems.
  15     They are part of the following ALI chipsets:
  16        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
  17        with AGP and 100MHz CPU Front Side bus
  18        "Aladdin V": Includes the M1541 Socket 7 North bridge
  19        with AGP and 100MHz CPU Front Side bus
  20        "Aladdin IV": Includes the M1541 Socket 7 North bridge
  21        with host bus up to 83.3 MHz.
  22     For an overview of these chips see http://www.acerlabs.com
  23 
  24     The M1533/M1543C devices appear as FOUR separate devices
  25     on the PCI bus. An output of lspci will show something similar
  26     to the following:
  27 
  28         00:02.0 USB Controller: Acer Laboratories Inc. M5237
  29         00:03.0 Bridge: Acer Laboratories Inc. M7101
  30         00:07.0 ISA bridge: Acer Laboratories Inc. M1533
  31         00:0f.0 IDE interface: Acer Laboratories Inc. M5229
  32 
  33     The SMB controller is part of the 7101 device, which is an
  34     ACPI-compliant Power Management Unit (PMU).
  35 
  36     The whole 7101 device has to be enabled for the SMB to work.
  37     You can't just enable the SMB alone.
  38     The SMB and the ACPI have separate I/O spaces.
  39     We make sure that the SMB is enabled. We leave the ACPI alone.
  40 
  41     This driver controls the SMB Host only.
  42     The SMB Slave controller on the M15X3 is not enabled.
  43 
  44     This driver does not use interrupts.
  45 */
  46 
  47 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
  48 
  49 #include <linux/module.h>
  50 #include <linux/pci.h>
  51 #include <linux/kernel.h>
  52 #include <linux/stddef.h>
  53 #include <linux/ioport.h>
  54 #include <linux/delay.h>
  55 #include <linux/i2c.h>
  56 #include <linux/acpi.h>
  57 #include <linux/io.h>
  58 
  59 /* ALI15X3 SMBus address offsets */
  60 #define SMBHSTSTS       (0 + ali15x3_smba)
  61 #define SMBHSTCNT       (1 + ali15x3_smba)
  62 #define SMBHSTSTART     (2 + ali15x3_smba)
  63 #define SMBHSTCMD       (7 + ali15x3_smba)
  64 #define SMBHSTADD       (3 + ali15x3_smba)
  65 #define SMBHSTDAT0      (4 + ali15x3_smba)
  66 #define SMBHSTDAT1      (5 + ali15x3_smba)
  67 #define SMBBLKDAT       (6 + ali15x3_smba)
  68 
  69 /* PCI Address Constants */
  70 #define SMBCOM          0x004
  71 #define SMBBA           0x014
  72 #define SMBATPC         0x05B   /* used to unlock xxxBA registers */
  73 #define SMBHSTCFG       0x0E0
  74 #define SMBSLVC         0x0E1
  75 #define SMBCLK          0x0E2
  76 #define SMBREV          0x008
  77 
  78 /* Other settings */
  79 #define MAX_TIMEOUT             200     /* times 1/100 sec */
  80 #define ALI15X3_SMB_IOSIZE      32
  81 
  82 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
  83    We don't use these here. If the bases aren't set to some value we
  84    tell user to upgrade BIOS and we fail.
  85 */
  86 #define ALI15X3_SMB_DEFAULTBASE 0xE800
  87 
  88 /* ALI15X3 address lock bits */
  89 #define ALI15X3_LOCK            0x06
  90 
  91 /* ALI15X3 command constants */
  92 #define ALI15X3_ABORT           0x02
  93 #define ALI15X3_T_OUT           0x04
  94 #define ALI15X3_QUICK           0x00
  95 #define ALI15X3_BYTE            0x10
  96 #define ALI15X3_BYTE_DATA       0x20
  97 #define ALI15X3_WORD_DATA       0x30
  98 #define ALI15X3_BLOCK_DATA      0x40
  99 #define ALI15X3_BLOCK_CLR       0x80
 100 
 101 /* ALI15X3 status register bits */
 102 #define ALI15X3_STS_IDLE        0x04
 103 #define ALI15X3_STS_BUSY        0x08
 104 #define ALI15X3_STS_DONE        0x10
 105 #define ALI15X3_STS_DEV         0x20    /* device error */
 106 #define ALI15X3_STS_COLL        0x40    /* collision or no response */
 107 #define ALI15X3_STS_TERM        0x80    /* terminated by abort */
 108 #define ALI15X3_STS_ERR         0xE0    /* all the bad error bits */
 109 
 110 
 111 /* If force_addr is set to anything different from 0, we forcibly enable
 112    the device at the given address. */
 113 static u16 force_addr;
 114 module_param_hw(force_addr, ushort, ioport, 0);
 115 MODULE_PARM_DESC(force_addr,
 116                  "Initialize the base address of the i2c controller");
 117 
 118 static struct pci_driver ali15x3_driver;
 119 static unsigned short ali15x3_smba;
 120 
 121 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
 122 {
 123         u16 a;
 124         unsigned char temp;
 125 
 126         /* Check the following things:
 127                 - SMB I/O address is initialized
 128                 - Device is enabled
 129                 - We can use the addresses
 130         */
 131 
 132         /* Unlock the register.
 133            The data sheet says that the address registers are read-only
 134            if the lock bits are 1, but in fact the address registers
 135            are zero unless you clear the lock bits.
 136         */
 137         pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
 138         if (temp & ALI15X3_LOCK) {
 139                 temp &= ~ALI15X3_LOCK;
 140                 pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
 141         }
 142 
 143         /* Determine the address of the SMBus area */
 144         pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
 145         ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
 146         if (ali15x3_smba == 0 && force_addr == 0) {
 147                 dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
 148                         "- upgrade BIOS or use force_addr=0xaddr\n");
 149                 return -ENODEV;
 150         }
 151 
 152         if(force_addr)
 153                 ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
 154 
 155         if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
 156                               ali15x3_driver.name))
 157                 return -EBUSY;
 158 
 159         if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
 160                             ali15x3_driver.name)) {
 161                 dev_err(&ALI15X3_dev->dev,
 162                         "ALI15X3_smb region 0x%x already in use!\n",
 163                         ali15x3_smba);
 164                 return -ENODEV;
 165         }
 166 
 167         if(force_addr) {
 168                 dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
 169                         ali15x3_smba);
 170                 if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
 171                                                                 SMBBA,
 172                                                                 ali15x3_smba))
 173                         goto error;
 174                 if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
 175                                                                 SMBBA, &a))
 176                         goto error;
 177                 if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
 178                         /* make sure it works */
 179                         dev_err(&ALI15X3_dev->dev,
 180                                 "force address failed - not supported?\n");
 181                         goto error;
 182                 }
 183         }
 184         /* check if whole device is enabled */
 185         pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
 186         if ((temp & 1) == 0) {
 187                 dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
 188                 pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
 189         }
 190 
 191         /* Is SMB Host controller enabled? */
 192         pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
 193         if ((temp & 1) == 0) {
 194                 dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
 195                 pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
 196         }
 197 
 198         /* set SMB clock to 74KHz as recommended in data sheet */
 199         pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
 200 
 201         /*
 202           The interrupt routing for SMB is set up in register 0x77 in the
 203           1533 ISA Bridge device, NOT in the 7101 device.
 204           Don't bother with finding the 1533 device and reading the register.
 205         if ((....... & 0x0F) == 1)
 206                 dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
 207         */
 208         pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
 209         dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
 210         dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
 211 
 212         return 0;
 213 error:
 214         release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
 215         return -ENODEV;
 216 }
 217 
 218 /* Another internally used function */
 219 static int ali15x3_transaction(struct i2c_adapter *adap)
 220 {
 221         int temp;
 222         int result = 0;
 223         int timeout = 0;
 224 
 225         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
 226                 "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
 227                 inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
 228                 inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 229 
 230         /* get status */
 231         temp = inb_p(SMBHSTSTS);
 232 
 233         /* Make sure the SMBus host is ready to start transmitting */
 234         /* Check the busy bit first */
 235         if (temp & ALI15X3_STS_BUSY) {
 236         /*
 237            If the host controller is still busy, it may have timed out in the
 238            previous transaction, resulting in a "SMBus Timeout" Dev.
 239            I've tried the following to reset a stuck busy bit.
 240                 1. Reset the controller with an ABORT command.
 241                    (this doesn't seem to clear the controller if an external
 242                    device is hung)
 243                 2. Reset the controller and the other SMBus devices with a
 244                    T_OUT command.  (this clears the host busy bit if an
 245                    external device is hung, but it comes back upon a new access
 246                    to a device)
 247                 3. Disable and reenable the controller in SMBHSTCFG
 248            Worst case, nothing seems to work except power reset.
 249         */
 250         /* Abort - reset the host controller */
 251         /*
 252            Try resetting entire SMB bus, including other devices -
 253            This may not work either - it clears the BUSY bit but
 254            then the BUSY bit may come back on when you try and use the chip again.
 255            If that's the case you are stuck.
 256         */
 257                 dev_info(&adap->dev, "Resetting entire SMB Bus to "
 258                         "clear busy condition (%02x)\n", temp);
 259                 outb_p(ALI15X3_T_OUT, SMBHSTCNT);
 260                 temp = inb_p(SMBHSTSTS);
 261         }
 262 
 263         /* now check the error bits and the busy bit */
 264         if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
 265                 /* do a clear-on-write */
 266                 outb_p(0xFF, SMBHSTSTS);
 267                 if ((temp = inb_p(SMBHSTSTS)) &
 268                     (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
 269                         /* this is probably going to be correctable only by a power reset
 270                            as one of the bits now appears to be stuck */
 271                         /* This may be a bus or device with electrical problems. */
 272                         dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
 273                                 "controller or device on bus is probably hung\n",
 274                                 temp);
 275                         return -EBUSY;
 276                 }
 277         } else {
 278                 /* check and clear done bit */
 279                 if (temp & ALI15X3_STS_DONE) {
 280                         outb_p(temp, SMBHSTSTS);
 281                 }
 282         }
 283 
 284         /* start the transaction by writing anything to the start register */
 285         outb_p(0xFF, SMBHSTSTART);
 286 
 287         /* We will always wait for a fraction of a second! */
 288         timeout = 0;
 289         do {
 290                 msleep(1);
 291                 temp = inb_p(SMBHSTSTS);
 292         } while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
 293                  && (timeout++ < MAX_TIMEOUT));
 294 
 295         /* If the SMBus is still busy, we give up */
 296         if (timeout > MAX_TIMEOUT) {
 297                 result = -ETIMEDOUT;
 298                 dev_err(&adap->dev, "SMBus Timeout!\n");
 299         }
 300 
 301         if (temp & ALI15X3_STS_TERM) {
 302                 result = -EIO;
 303                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 304         }
 305 
 306         /*
 307           Unfortunately the ALI SMB controller maps "no response" and "bus
 308           collision" into a single bit. No response is the usual case so don't
 309           do a printk.
 310           This means that bus collisions go unreported.
 311         */
 312         if (temp & ALI15X3_STS_COLL) {
 313                 result = -ENXIO;
 314                 dev_dbg(&adap->dev,
 315                         "Error: no response or bus collision ADD=%02x\n",
 316                         inb_p(SMBHSTADD));
 317         }
 318 
 319         /* haven't ever seen this */
 320         if (temp & ALI15X3_STS_DEV) {
 321                 result = -EIO;
 322                 dev_err(&adap->dev, "Error: device error\n");
 323         }
 324         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
 325                 "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
 326                 inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
 327                 inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 328         return result;
 329 }
 330 
 331 /* Return negative errno on error. */
 332 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
 333                    unsigned short flags, char read_write, u8 command,
 334                    int size, union i2c_smbus_data * data)
 335 {
 336         int i, len;
 337         int temp;
 338         int timeout;
 339 
 340         /* clear all the bits (clear-on-write) */
 341         outb_p(0xFF, SMBHSTSTS);
 342         /* make sure SMBus is idle */
 343         temp = inb_p(SMBHSTSTS);
 344         for (timeout = 0;
 345              (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
 346              timeout++) {
 347                 msleep(1);
 348                 temp = inb_p(SMBHSTSTS);
 349         }
 350         if (timeout >= MAX_TIMEOUT) {
 351                 dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 352         }
 353 
 354         switch (size) {
 355         case I2C_SMBUS_QUICK:
 356                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 357                        SMBHSTADD);
 358                 size = ALI15X3_QUICK;
 359                 break;
 360         case I2C_SMBUS_BYTE:
 361                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 362                        SMBHSTADD);
 363                 if (read_write == I2C_SMBUS_WRITE)
 364                         outb_p(command, SMBHSTCMD);
 365                 size = ALI15X3_BYTE;
 366                 break;
 367         case I2C_SMBUS_BYTE_DATA:
 368                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 369                        SMBHSTADD);
 370                 outb_p(command, SMBHSTCMD);
 371                 if (read_write == I2C_SMBUS_WRITE)
 372                         outb_p(data->byte, SMBHSTDAT0);
 373                 size = ALI15X3_BYTE_DATA;
 374                 break;
 375         case I2C_SMBUS_WORD_DATA:
 376                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 377                        SMBHSTADD);
 378                 outb_p(command, SMBHSTCMD);
 379                 if (read_write == I2C_SMBUS_WRITE) {
 380                         outb_p(data->word & 0xff, SMBHSTDAT0);
 381                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 382                 }
 383                 size = ALI15X3_WORD_DATA;
 384                 break;
 385         case I2C_SMBUS_BLOCK_DATA:
 386                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 387                        SMBHSTADD);
 388                 outb_p(command, SMBHSTCMD);
 389                 if (read_write == I2C_SMBUS_WRITE) {
 390                         len = data->block[0];
 391                         if (len < 0) {
 392                                 len = 0;
 393                                 data->block[0] = len;
 394                         }
 395                         if (len > 32) {
 396                                 len = 32;
 397                                 data->block[0] = len;
 398                         }
 399                         outb_p(len, SMBHSTDAT0);
 400                         /* Reset SMBBLKDAT */
 401                         outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
 402                         for (i = 1; i <= len; i++)
 403                                 outb_p(data->block[i], SMBBLKDAT);
 404                 }
 405                 size = ALI15X3_BLOCK_DATA;
 406                 break;
 407         default:
 408                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 409                 return -EOPNOTSUPP;
 410         }
 411 
 412         outb_p(size, SMBHSTCNT);        /* output command */
 413 
 414         temp = ali15x3_transaction(adap);
 415         if (temp)
 416                 return temp;
 417 
 418         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
 419                 return 0;
 420 
 421 
 422         switch (size) {
 423         case ALI15X3_BYTE:      /* Result put in SMBHSTDAT0 */
 424                 data->byte = inb_p(SMBHSTDAT0);
 425                 break;
 426         case ALI15X3_BYTE_DATA:
 427                 data->byte = inb_p(SMBHSTDAT0);
 428                 break;
 429         case ALI15X3_WORD_DATA:
 430                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 431                 break;
 432         case ALI15X3_BLOCK_DATA:
 433                 len = inb_p(SMBHSTDAT0);
 434                 if (len > 32)
 435                         len = 32;
 436                 data->block[0] = len;
 437                 /* Reset SMBBLKDAT */
 438                 outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
 439                 for (i = 1; i <= data->block[0]; i++) {
 440                         data->block[i] = inb_p(SMBBLKDAT);
 441                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 442                                 len, i, data->block[i]);
 443                 }
 444                 break;
 445         }
 446         return 0;
 447 }
 448 
 449 static u32 ali15x3_func(struct i2c_adapter *adapter)
 450 {
 451         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 452             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 453             I2C_FUNC_SMBUS_BLOCK_DATA;
 454 }
 455 
 456 static const struct i2c_algorithm smbus_algorithm = {
 457         .smbus_xfer     = ali15x3_access,
 458         .functionality  = ali15x3_func,
 459 };
 460 
 461 static struct i2c_adapter ali15x3_adapter = {
 462         .owner          = THIS_MODULE,
 463         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 464         .algo           = &smbus_algorithm,
 465 };
 466 
 467 static const struct pci_device_id ali15x3_ids[] = {
 468         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 469         { 0, }
 470 };
 471 
 472 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
 473 
 474 static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
 475 {
 476         if (ali15x3_setup(dev)) {
 477                 dev_err(&dev->dev,
 478                         "ALI15X3 not detected, module not inserted.\n");
 479                 return -ENODEV;
 480         }
 481 
 482         /* set up the sysfs linkage to our parent device */
 483         ali15x3_adapter.dev.parent = &dev->dev;
 484 
 485         snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
 486                 "SMBus ALI15X3 adapter at %04x", ali15x3_smba);
 487         return i2c_add_adapter(&ali15x3_adapter);
 488 }
 489 
 490 static void ali15x3_remove(struct pci_dev *dev)
 491 {
 492         i2c_del_adapter(&ali15x3_adapter);
 493         release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
 494 }
 495 
 496 static struct pci_driver ali15x3_driver = {
 497         .name           = "ali15x3_smbus",
 498         .id_table       = ali15x3_ids,
 499         .probe          = ali15x3_probe,
 500         .remove         = ali15x3_remove,
 501 };
 502 
 503 module_pci_driver(ali15x3_driver);
 504 
 505 MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl>, "
 506                 "Philip Edelbrock <phil@netroedge.com>, "
 507                 "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
 508 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
 509 MODULE_LICENSE("GPL");