err.no Git - linux-2.6/blob - drivers/i2c/busses/scx200_acb.c

   1 /*
   2     Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
   3
   4     National Semiconductor SCx200 ACCESS.bus support
   5     Also supports the AMD CS5535 and AMD CS5536
   6
   7     Based on i2c-keywest.c which is:
   8         Copyright (c) 2001 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   9         Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
  10
  11     This program is free software; you can redistribute it and/or
  12     modify it under the terms of the GNU General Public License as
  13     published by the Free Software Foundation; either version 2 of the
  14     License, or (at your option) any later version.
  15
  16     This program is distributed in the hope that it will be useful,
  17     but WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19     General Public License for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with this program; if not, write to the Free Software
  23     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/i2c.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/pci.h>
  33 #include <linux/delay.h>
  34 #include <asm/io.h>
  35 #include <asm/msr.h>
  36
  37 #include <linux/scx200.h>
  38
  39 #define NAME "scx200_acb"
  40
  41 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
  42 MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
  43 MODULE_LICENSE("GPL");
  44
  45 #define MAX_DEVICES 4
  46 static int base[MAX_DEVICES] = { 0x820, 0x840 };
  47 module_param_array(base, int, NULL, 0);
  48 MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
  49
  50 /* The hardware supports interrupt driven mode too, but I haven't
  51    implemented that. */
  52 #define POLLED_MODE 1
  53 #define POLL_TIMEOUT (HZ)
  54
  55 enum scx200_acb_state {
  56         state_idle,
  57         state_address,
  58         state_command,
  59         state_repeat_start,
  60         state_quick,
  61         state_read,
  62         state_write,
  63 };
  64
  65 static const char *scx200_acb_state_name[] = {
  66         "idle",
  67         "address",
  68         "command",
  69         "repeat_start",
  70         "quick",
  71         "read",
  72         "write",
  73 };
  74
  75 /* Physical interface */
  76 struct scx200_acb_iface {
  77         struct scx200_acb_iface *next;
  78         struct i2c_adapter adapter;
  79         unsigned base;
  80         struct semaphore sem;
  81
  82         /* State machine data */
  83         enum scx200_acb_state state;
  84         int result;
  85         u8 address_byte;
  86         u8 command;
  87         u8 *ptr;
  88         char needs_reset;
  89         unsigned len;
  90 };
  91
  92 /* Register Definitions */
  93 #define ACBSDA          (iface->base + 0)
  94 #define ACBST           (iface->base + 1)
  95 #define    ACBST_SDAST          0x40 /* SDA Status */
  96 #define    ACBST_BER            0x20
  97 #define    ACBST_NEGACK         0x10 /* Negative Acknowledge */
  98 #define    ACBST_STASTR         0x08 /* Stall After Start */
  99 #define    ACBST_MASTER         0x02
 100 #define ACBCST          (iface->base + 2)
 101 #define    ACBCST_BB            0x02
 102 #define ACBCTL1         (iface->base + 3)
 103 #define    ACBCTL1_STASTRE      0x80
 104 #define    ACBCTL1_NMINTE       0x40
 105 #define    ACBCTL1_ACK          0x10
 106 #define    ACBCTL1_STOP         0x02
 107 #define    ACBCTL1_START        0x01
 108 #define ACBADDR         (iface->base + 4)
 109 #define ACBCTL2         (iface->base + 5)
 110 #define    ACBCTL2_ENABLE       0x01
 111
 112 /************************************************************************/
 113
 114 static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
 115 {
 116         const char *errmsg;
 117
 118         dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
 119                 scx200_acb_state_name[iface->state], status);
 120
 121         if (status & ACBST_BER) {
 122                 errmsg = "bus error";
 123                 goto error;
 124         }
 125         if (!(status & ACBST_MASTER)) {
 126                 errmsg = "not master";
 127                 goto error;
 128         }
 129         if (status & ACBST_NEGACK) {
 130                 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
 131                         scx200_acb_state_name[iface->state]);
 132
 133                 iface->state = state_idle;
 134                 iface->result = -ENXIO;
 135
 136                 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
 137                 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
 138                 return;
 139         }
 140
 141         switch (iface->state) {
 142         case state_idle:
 143                 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
 144                 break;
 145
 146         case state_address:
 147                 /* Do a pointer write first */
 148                 outb(iface->address_byte & ~1, ACBSDA);
 149
 150                 iface->state = state_command;
 151                 break;
 152
 153         case state_command:
 154                 outb(iface->command, ACBSDA);
 155
 156                 if (iface->address_byte & 1)
 157                         iface->state = state_repeat_start;
 158                 else
 159                         iface->state = state_write;
 160                 break;
 161
 162         case state_repeat_start:
 163                 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
 164                 /* fallthrough */
 165
 166         case state_quick:
 167                 if (iface->address_byte & 1) {
 168                         if (iface->len == 1)
 169                                 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
 170                         else
 171                                 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
 172                         outb(iface->address_byte, ACBSDA);
 173
 174                         iface->state = state_read;
 175                 } else {
 176                         outb(iface->address_byte, ACBSDA);
 177
 178                         iface->state = state_write;
 179                 }
 180                 break;
 181
 182         case state_read:
 183                 /* Set ACK if receiving the last byte */
 184                 if (iface->len == 1)
 185                         outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
 186                 else
 187                         outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
 188
 189                 *iface->ptr++ = inb(ACBSDA);
 190                 --iface->len;
 191
 192                 if (iface->len == 0) {
 193                         iface->result = 0;
 194                         iface->state = state_idle;
 195                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
 196                 }
 197
 198                 break;
 199
 200         case state_write:
 201                 if (iface->len == 0) {
 202                         iface->result = 0;
 203                         iface->state = state_idle;
 204                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
 205                         break;
 206                 }
 207
 208                 outb(*iface->ptr++, ACBSDA);
 209                 --iface->len;
 210
 211                 break;
 212         }
 213
 214         return;
 215
 216  error:
 217         dev_err(&iface->adapter.dev, "%s in state %s\n", errmsg,
 218                 scx200_acb_state_name[iface->state]);
 219
 220         iface->state = state_idle;
 221         iface->result = -EIO;
 222         iface->needs_reset = 1;
 223 }
 224
 225 #ifdef POLLED_MODE
 226 static void scx200_acb_poll(struct scx200_acb_iface *iface)
 227 {
 228         u8 status;
 229         unsigned long timeout;
 230
 231         timeout = jiffies + POLL_TIMEOUT;
 232         while (time_before(jiffies, timeout)) {
 233                 status = inb(ACBST);
 234                 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
 235                         scx200_acb_machine(iface, status);
 236                         return;
 237                 }
 238                 msleep(10);
 239         }
 240
 241         dev_err(&iface->adapter.dev, "timeout in state %s\n",
 242                 scx200_acb_state_name[iface->state]);
 243
 244         iface->state = state_idle;
 245         iface->result = -EIO;
 246         iface->needs_reset = 1;
 247 }
 248 #endif /* POLLED_MODE */
 249
 250 static void scx200_acb_reset(struct scx200_acb_iface *iface)
 251 {
 252         /* Disable the ACCESS.bus device and Configure the SCL
 253            frequency: 16 clock cycles */
 254         outb(0x70, ACBCTL2);
 255         /* Polling mode */
 256         outb(0, ACBCTL1);
 257         /* Disable slave address */
 258         outb(0, ACBADDR);
 259         /* Enable the ACCESS.bus device */
 260         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
 261         /* Free STALL after START */
 262         outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
 263         /* Send a STOP */
 264         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
 265         /* Clear BER, NEGACK and STASTR bits */
 266         outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
 267         /* Clear BB bit */
 268         outb(inb(ACBCST) | ACBCST_BB, ACBCST);
 269 }
 270
 271 static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
 272                                  u16 address, unsigned short flags,
 273                                  char rw, u8 command, int size,
 274                                  union i2c_smbus_data *data)
 275 {
 276         struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
 277         int len;
 278         u8 *buffer;
 279         u16 cur_word;
 280         int rc;
 281
 282         switch (size) {
 283         case I2C_SMBUS_QUICK:
 284                 len = 0;
 285                 buffer = NULL;
 286                 break;
 287
 288         case I2C_SMBUS_BYTE:
 289                 len = 1;
 290                 buffer = rw ? &data->byte : &command;
 291                 break;
 292
 293         case I2C_SMBUS_BYTE_DATA:
 294                 len = 1;
 295                 buffer = &data->byte;
 296                 break;
 297
 298         case I2C_SMBUS_WORD_DATA:
 299                 len = 2;
 300                 cur_word = cpu_to_le16(data->word);
 301                 buffer = (u8 *)&cur_word;
 302                 break;
 303
 304         case I2C_SMBUS_BLOCK_DATA:
 305                 len = data->block[0];
 306                 buffer = &data->block[1];
 307                 break;
 308
 309         default:
 310                 return -EINVAL;
 311         }
 312
 313         dev_dbg(&adapter->dev,
 314                 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
 315                 size, address, command, len, rw);
 316
 317         if (!len && rw == I2C_SMBUS_READ) {
 318                 dev_dbg(&adapter->dev, "zero length read\n");
 319                 return -EINVAL;
 320         }
 321
 322         down(&iface->sem);
 323
 324         iface->address_byte = (address << 1) | rw;
 325         iface->command = command;
 326         iface->ptr = buffer;
 327         iface->len = len;
 328         iface->result = -EINVAL;
 329         iface->needs_reset = 0;
 330
 331         outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
 332
 333         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
 334                 iface->state = state_quick;
 335         else
 336                 iface->state = state_address;
 337
 338 #ifdef POLLED_MODE
 339         while (iface->state != state_idle)
 340                 scx200_acb_poll(iface);
 341 #else /* POLLED_MODE */
 342 #error Interrupt driven mode not implemented
 343 #endif /* POLLED_MODE */
 344
 345         if (iface->needs_reset)
 346                 scx200_acb_reset(iface);
 347
 348         rc = iface->result;
 349
 350         up(&iface->sem);
 351
 352         if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
 353                 data->word = le16_to_cpu(cur_word);
 354
 355 #ifdef DEBUG
 356         dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
 357         if (buffer) {
 358                 int i;
 359                 printk(" data:");
 360                 for (i = 0; i < len; ++i)
 361                         printk(" %02x", buffer[i]);
 362         }
 363         printk("\n");
 364 #endif
 365
 366         return rc;
 367 }
 368
 369 static u32 scx200_acb_func(struct i2c_adapter *adapter)
 370 {
 371         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 372                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 373                I2C_FUNC_SMBUS_BLOCK_DATA;
 374 }
 375
 376 /* For now, we only handle combined mode (smbus) */
 377 static struct i2c_algorithm scx200_acb_algorithm = {
 378         .smbus_xfer     = scx200_acb_smbus_xfer,
 379         .functionality  = scx200_acb_func,
 380 };
 381
 382 static struct scx200_acb_iface *scx200_acb_list;
 383 static DECLARE_MUTEX(scx200_acb_list_mutex);
 384
 385 static int scx200_acb_probe(struct scx200_acb_iface *iface)
 386 {
 387         u8 val;
 388
 389         /* Disable the ACCESS.bus device and Configure the SCL
 390            frequency: 16 clock cycles */
 391         outb(0x70, ACBCTL2);
 392
 393         if (inb(ACBCTL2) != 0x70) {
 394                 pr_debug(NAME ": ACBCTL2 readback failed\n");
 395                 return -ENXIO;
 396         }
 397
 398         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
 399
 400         val = inb(ACBCTL1);
 401         if (val) {
 402                 pr_debug(NAME ": disabled, but ACBCTL1=0x%02x\n",
 403                         val);
 404                 return -ENXIO;
 405         }
 406
 407         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
 408
 409         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
 410
 411         val = inb(ACBCTL1);
 412         if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
 413                 pr_debug(NAME ": enabled, but NMINTE won't be set, "
 414                          "ACBCTL1=0x%02x\n", val);
 415                 return -ENXIO;
 416         }
 417
 418         return 0;
 419 }
 420
 421 static int  __init scx200_acb_create(const char *text, int base, int index)
 422 {
 423         struct scx200_acb_iface *iface;
 424         struct i2c_adapter *adapter;
 425         int rc;
 426         char description[64];
 427
 428         iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 429         if (!iface) {
 430                 printk(KERN_ERR NAME ": can't allocate memory\n");
 431                 rc = -ENOMEM;
 432                 goto errout;
 433         }
 434
 435         adapter = &iface->adapter;
 436         i2c_set_adapdata(adapter, iface);
 437         snprintf(adapter->name, I2C_NAME_SIZE, "%s ACB%d", text, index);
 438         adapter->owner = THIS_MODULE;
 439         adapter->id = I2C_HW_SMBUS_SCX200;
 440         adapter->algo = &scx200_acb_algorithm;
 441         adapter->class = I2C_CLASS_HWMON;
 442
 443         init_MUTEX(&iface->sem);
 444
 445         snprintf(description, sizeof(description), "%s ACCESS.bus [%s]",
 446                  text, adapter->name);
 447
 448         if (request_region(base, 8, description) == 0) {
 449                 printk(KERN_ERR NAME ": can't allocate io 0x%x-0x%x\n",
 450                         base, base + 8-1);
 451                 rc = -EBUSY;
 452                 goto errout_free;
 453         }
 454         iface->base = base;
 455
 456         rc = scx200_acb_probe(iface);
 457         if (rc) {
 458                 printk(KERN_WARNING NAME ": probe failed\n");
 459                 goto errout_release;
 460         }
 461
 462         scx200_acb_reset(iface);
 463
 464         if (i2c_add_adapter(adapter) < 0) {
 465                 printk(KERN_ERR NAME ": failed to register\n");
 466                 rc = -ENODEV;
 467                 goto errout_release;
 468         }
 469
 470         down(&scx200_acb_list_mutex);
 471         iface->next = scx200_acb_list;
 472         scx200_acb_list = iface;
 473         up(&scx200_acb_list_mutex);
 474
 475         return 0;
 476
 477  errout_release:
 478         release_region(iface->base, 8);
 479  errout_free:
 480         kfree(iface);
 481  errout:
 482         return rc;
 483 }
 484
 485 static struct pci_device_id scx200[] = {
 486         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
 487         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
 488         { },
 489 };
 490
 491 static struct pci_device_id divil_pci[] = {
 492         { PCI_DEVICE(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA) },
 493         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
 494         { } /* NULL entry */
 495 };
 496
 497 #define MSR_LBAR_SMB            0x5140000B
 498
 499 static int scx200_add_cs553x(void)
 500 {
 501         u32     low, hi;
 502         u32     smb_base;
 503
 504         /* Grab & reserve the SMB I/O range */
 505         rdmsr(MSR_LBAR_SMB, low, hi);
 506
 507         /* Check the IO mask and whether SMB is enabled */
 508         if (hi != 0x0000F001) {
 509                 printk(KERN_WARNING NAME ": SMBus not enabled\n");
 510                 return -ENODEV;
 511         }
 512
 513         /* SMBus IO size is 8 bytes */
 514         smb_base = low & 0x0000FFF8;
 515
 516         return scx200_acb_create("CS5535", smb_base, 0);
 517 }
 518
 519 static int __init scx200_acb_init(void)
 520 {
 521         int i;
 522         int     rc = -ENODEV;
 523
 524         pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
 525
 526         /* Verify that this really is a SCx200 processor */
 527         if (pci_dev_present(scx200)) {
 528                 for (i = 0; i < MAX_DEVICES; ++i) {
 529                         if (base[i] > 0)
 530                                 rc = scx200_acb_create("SCx200", base[i], i);
 531                 }
 532         } else if (pci_dev_present(divil_pci))
 533                 rc = scx200_add_cs553x();
 534
 535         return rc;
 536 }
 537
 538 static void __exit scx200_acb_cleanup(void)
 539 {
 540         struct scx200_acb_iface *iface;
 541
 542         down(&scx200_acb_list_mutex);
 543         while ((iface = scx200_acb_list) != NULL) {
 544                 scx200_acb_list = iface->next;
 545                 up(&scx200_acb_list_mutex);
 546
 547                 i2c_del_adapter(&iface->adapter);
 548                 release_region(iface->base, 8);
 549                 kfree(iface);
 550                 down(&scx200_acb_list_mutex);
 551         }
 552         up(&scx200_acb_list_mutex);
 553 }
 554
 555 module_init(scx200_acb_init);
 556 module_exit(scx200_acb_cleanup);