drivers/i2c/busses/i2c-sis96x.c

   1 /*
   2     sis96x.c - Part of lm_sensors, Linux kernel modules for hardware
   3               monitoring
   4
   5     Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 /*
  23     This module must be considered BETA unless and until
  24     the chipset manufacturer releases a datasheet.
  25     The register definitions are based on the SiS630.
  26
  27     This module relies on quirk_sis_96x_smbus (drivers/pci/quirks.c)
  28     for just about every machine for which users have reported.
  29     If this module isn't detecting your 96x south bridge, have a
  30     look there.
  31
  32     We assume there can only be one SiS96x with one SMBus interface.
  33 */
  34
  35 #include <linux/module.h>
  36 #include <linux/pci.h>
  37 #include <linux/kernel.h>
  38 #include <linux/delay.h>
  39 #include <linux/stddef.h>
  40 #include <linux/sched.h>
  41 #include <linux/ioport.h>
  42 #include <linux/i2c.h>
  43 #include <linux/init.h>
  44 #include <asm/io.h>
  45
  46 /*
  47         HISTORY:
  48         2003-05-11      1.0.0   Updated from lm_sensors project for kernel 2.5
  49                                 (was i2c-sis645.c from lm_sensors 2.7.0)
  50 */
  51 #define SIS96x_VERSION "1.0.0"
  52
  53 /* base address register in PCI config space */
  54 #define SIS96x_BAR 0x04
  55
  56 /* SiS96x SMBus registers */
  57 #define SMB_STS      0x00
  58 #define SMB_EN       0x01
  59 #define SMB_CNT      0x02
  60 #define SMB_HOST_CNT 0x03
  61 #define SMB_ADDR     0x04
  62 #define SMB_CMD      0x05
  63 #define SMB_PCOUNT   0x06
  64 #define SMB_COUNT    0x07
  65 #define SMB_BYTE     0x08
  66 #define SMB_DEV_ADDR 0x10
  67 #define SMB_DB0      0x11
  68 #define SMB_DB1      0x12
  69 #define SMB_SAA      0x13
  70
  71 /* register count for request_region */
  72 #define SMB_IOSIZE 0x20
  73
  74 /* Other settings */
  75 #define MAX_TIMEOUT 500
  76
  77 /* SiS96x SMBus constants */
  78 #define SIS96x_QUICK      0x00
  79 #define SIS96x_BYTE       0x01
  80 #define SIS96x_BYTE_DATA  0x02
  81 #define SIS96x_WORD_DATA  0x03
  82 #define SIS96x_PROC_CALL  0x04
  83 #define SIS96x_BLOCK_DATA 0x05
  84
  85 static struct i2c_adapter sis96x_adapter;
  86 static u16 sis96x_smbus_base = 0;
  87
  88 static inline u8 sis96x_read(u8 reg)
  89 {
  90         return inb(sis96x_smbus_base + reg) ;
  91 }
  92
  93 static inline void sis96x_write(u8 reg, u8 data)
  94 {
  95         outb(data, sis96x_smbus_base + reg) ;
  96 }
  97
  98 /* Execute a SMBus transaction.
  99    int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA
 100  */
 101 static int sis96x_transaction(int size)
 102 {
 103         int temp;
 104         int result = 0;
 105         int timeout = 0;
 106
 107         dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);
 108
 109         /* Make sure the SMBus host is ready to start transmitting */
 110         if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
 111
 112                 dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "
 113                         "Resetting...\n", temp);
 114
 115                 /* kill the transaction */
 116                 sis96x_write(SMB_HOST_CNT, 0x20);
 117
 118                 /* check it again */
 119                 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
 120                         dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
 121                         return -1;
 122                 } else {
 123                         dev_dbg(&sis96x_adapter.dev, "Successful\n");
 124                 }
 125         }
 126
 127         /* Turn off timeout interrupts, set fast host clock */
 128         sis96x_write(SMB_CNT, 0x20);
 129
 130         /* clear all (sticky) status flags */
 131         temp = sis96x_read(SMB_STS);
 132         sis96x_write(SMB_STS, temp & 0x1e);
 133
 134         /* start the transaction by setting bit 4 and size bits */
 135         sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));
 136
 137         /* We will always wait for a fraction of a second! */
 138         do {
 139                 msleep(1);
 140                 temp = sis96x_read(SMB_STS);
 141         } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
 142
 143         /* If the SMBus is still busy, we give up */
 144         if (timeout >= MAX_TIMEOUT) {
 145                 dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
 146                 result = -1;
 147         }
 148
 149         /* device error - probably missing ACK */
 150         if (temp & 0x02) {
 151                 dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
 152                 result = -1;
 153         }
 154
 155         /* bus collision */
 156         if (temp & 0x04) {
 157                 dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
 158                 result = -1;
 159         }
 160
 161         /* Finish up by resetting the bus */
 162         sis96x_write(SMB_STS, temp);
 163         if ((temp = sis96x_read(SMB_STS))) {
 164                 dev_dbg(&sis96x_adapter.dev, "Failed reset at "
 165                         "end of transaction! (0x%02x)\n", temp);
 166         }
 167
 168         return result;
 169 }
 170
 171 /* Return -1 on error. */
 172 static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
 173                          unsigned short flags, char read_write,
 174                          u8 command, int size, union i2c_smbus_data * data)
 175 {
 176
 177         switch (size) {
 178         case I2C_SMBUS_QUICK:
 179                 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 180                 size = SIS96x_QUICK;
 181                 break;
 182
 183         case I2C_SMBUS_BYTE:
 184                 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 185                 if (read_write == I2C_SMBUS_WRITE)
 186                         sis96x_write(SMB_CMD, command);
 187                 size = SIS96x_BYTE;
 188                 break;
 189
 190         case I2C_SMBUS_BYTE_DATA:
 191                 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 192                 sis96x_write(SMB_CMD, command);
 193                 if (read_write == I2C_SMBUS_WRITE)
 194                         sis96x_write(SMB_BYTE, data->byte);
 195                 size = SIS96x_BYTE_DATA;
 196                 break;
 197
 198         case I2C_SMBUS_PROC_CALL:
 199         case I2C_SMBUS_WORD_DATA:
 200                 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 201                 sis96x_write(SMB_CMD, command);
 202                 if (read_write == I2C_SMBUS_WRITE) {
 203                         sis96x_write(SMB_BYTE, data->word & 0xff);
 204                         sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
 205                 }
 206                 size = (size == I2C_SMBUS_PROC_CALL ?
 207                         SIS96x_PROC_CALL : SIS96x_WORD_DATA);
 208                 break;
 209
 210         case I2C_SMBUS_BLOCK_DATA:
 211                 /* TO DO: */
 212                 dev_info(&adap->dev, "SMBus block not implemented!\n");
 213                 return -1;
 214                 break;
 215
 216         default:
 217                 dev_info(&adap->dev, "Unsupported I2C size\n");
 218                 return -1;
 219                 break;
 220         }
 221
 222         if (sis96x_transaction(size))
 223                 return -1;
 224
 225         if ((size != SIS96x_PROC_CALL) &&
 226                 ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK)))
 227                 return 0;
 228
 229         switch (size) {
 230         case SIS96x_BYTE:
 231         case SIS96x_BYTE_DATA:
 232                 data->byte = sis96x_read(SMB_BYTE);
 233                 break;
 234
 235         case SIS96x_WORD_DATA:
 236         case SIS96x_PROC_CALL:
 237                 data->word = sis96x_read(SMB_BYTE) +
 238                                 (sis96x_read(SMB_BYTE + 1) << 8);
 239                 break;
 240         }
 241         return 0;
 242 }
 243
 244 static u32 sis96x_func(struct i2c_adapter *adapter)
 245 {
 246         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 247             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 248             I2C_FUNC_SMBUS_PROC_CALL;
 249 }
 250
 251 static struct i2c_algorithm smbus_algorithm = {
 252         .smbus_xfer     = sis96x_access,
 253         .functionality  = sis96x_func,
 254 };
 255
 256 static struct i2c_adapter sis96x_adapter = {
 257         .owner          = THIS_MODULE,
 258         .class          = I2C_CLASS_HWMON,
 259         .algo           = &smbus_algorithm,
 260         .name           = "unset",
 261 };
 262
 263 static struct pci_device_id sis96x_ids[] = {
 264         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },
 265         { 0, }
 266 };
 267
 268 MODULE_DEVICE_TABLE (pci, sis96x_ids);
 269
 270 static int __devinit sis96x_probe(struct pci_dev *dev,
 271                                 const struct pci_device_id *id)
 272 {
 273         u16 ww = 0;
 274         int retval;
 275
 276         if (sis96x_smbus_base) {
 277                 dev_err(&dev->dev, "Only one device supported.\n");
 278                 return -EBUSY;
 279         }
 280
 281         pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww);
 282         if (PCI_CLASS_SERIAL_SMBUS != ww) {
 283                 dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww);
 284                 return -ENODEV;
 285         }
 286
 287         sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR);
 288         if (!sis96x_smbus_base) {
 289                 dev_err(&dev->dev, "SiS96x SMBus base address "
 290                         "not initialized!\n");
 291                 return -EINVAL;
 292         }
 293         dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n",
 294                         sis96x_smbus_base);
 295
 296         /* Everything is happy, let's grab the memory and set things up. */
 297         if (!request_region(sis96x_smbus_base, SMB_IOSIZE, "sis96x-smbus")) {
 298                 dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x "
 299                         "already in use!\n", sis96x_smbus_base,
 300                         sis96x_smbus_base + SMB_IOSIZE - 1);
 301
 302                 sis96x_smbus_base = 0;
 303                 return -EINVAL;
 304         }
 305
 306         /* set up the driverfs linkage to our parent device */
 307         sis96x_adapter.dev.parent = &dev->dev;
 308
 309         snprintf(sis96x_adapter.name, I2C_NAME_SIZE,
 310                 "SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base);
 311
 312         if ((retval = i2c_add_adapter(&sis96x_adapter))) {
 313                 dev_err(&dev->dev, "Couldn't register adapter!\n");
 314                 release_region(sis96x_smbus_base, SMB_IOSIZE);
 315                 sis96x_smbus_base = 0;
 316         }
 317
 318         return retval;
 319 }
 320
 321 static void __devexit sis96x_remove(struct pci_dev *dev)
 322 {
 323         if (sis96x_smbus_base) {
 324                 i2c_del_adapter(&sis96x_adapter);
 325                 release_region(sis96x_smbus_base, SMB_IOSIZE);
 326                 sis96x_smbus_base = 0;
 327         }
 328 }
 329
 330 static struct pci_driver sis96x_driver = {
 331         .name           = "sis96x_smbus",
 332         .id_table       = sis96x_ids,
 333         .probe          = sis96x_probe,
 334         .remove         = __devexit_p(sis96x_remove),
 335 };
 336
 337 static int __init i2c_sis96x_init(void)
 338 {
 339         printk(KERN_INFO "i2c-sis96x version %s\n", SIS96x_VERSION);
 340         return pci_register_driver(&sis96x_driver);
 341 }
 342
 343 static void __exit i2c_sis96x_exit(void)
 344 {
 345         pci_unregister_driver(&sis96x_driver);
 346 }
 347
 348 MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
 349 MODULE_DESCRIPTION("SiS96x SMBus driver");
 350 MODULE_LICENSE("GPL");
 351
 352 /* Register initialization functions using helper macros */
 353 module_init(i2c_sis96x_init);
 354 module_exit(i2c_sis96x_exit);
 355