drivers/i2c/busses/i2c-ibm_iic.c

   1 /*
   2  * drivers/i2c/busses/i2c-ibm_iic.c
   3  *
   4  * Support for the IIC peripheral on IBM PPC 4xx
   5  *
   6  * Copyright (c) 2003, 2004 Zultys Technologies.
   7  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
   8  *
   9  * Copyright (c) 2008 PIKA Technologies
  10  * Sean MacLennan <smaclennan@pikatech.com>
  11  *
  12  * Based on original work by
  13  *      Ian DaSilva  <idasilva@mvista.com>
  14  *      Armin Kuster <akuster@mvista.com>
  15  *      Matt Porter  <mporter@mvista.com>
  16  *
  17  *      Copyright 2000-2003 MontaVista Software Inc.
  18  *
  19  * Original driver version was highly leveraged from i2c-elektor.c
  20  *
  21  *      Copyright 1995-97 Simon G. Vogl
  22  *                1998-99 Hans Berglund
  23  *
  24  *      With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>
  25  *      and even Frodo Looijaard <frodol@dds.nl>
  26  *
  27  * This program is free software; you can redistribute  it and/or modify it
  28  * under  the terms of  the GNU General  Public License as published by the
  29  * Free Software Foundation;  either version 2 of the  License, or (at your
  30  * option) any later version.
  31  *
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/kernel.h>
  36 #include <linux/ioport.h>
  37 #include <linux/delay.h>
  38 #include <linux/slab.h>
  39 #include <linux/init.h>
  40 #include <linux/interrupt.h>
  41 #include <asm/irq.h>
  42 #include <asm/io.h>
  43 #include <linux/i2c.h>
  44 #include <linux/i2c-id.h>
  45
  46 #ifdef CONFIG_IBM_OCP
  47 #include <asm/ocp.h>
  48 #include <asm/ibm4xx.h>
  49 #else
  50 #include <linux/of_platform.h>
  51 #endif
  52
  53 #include "i2c-ibm_iic.h"
  54
  55 #define DRIVER_VERSION "2.2"
  56
  57 MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION);
  58 MODULE_LICENSE("GPL");
  59
  60 static int iic_force_poll;
  61 module_param(iic_force_poll, bool, 0);
  62 MODULE_PARM_DESC(iic_force_poll, "Force polling mode");
  63
  64 static int iic_force_fast;
  65 module_param(iic_force_fast, bool, 0);
  66 MODULE_PARM_DESC(iic_force_fast, "Force fast mode (400 kHz)");
  67
  68 #define DBG_LEVEL 0
  69
  70 #ifdef DBG
  71 #undef DBG
  72 #endif
  73
  74 #ifdef DBG2
  75 #undef DBG2
  76 #endif
  77
  78 #if DBG_LEVEL > 0
  79 #  define DBG(f,x...)   printk(KERN_DEBUG "ibm-iic" f, ##x)
  80 #else
  81 #  define DBG(f,x...)   ((void)0)
  82 #endif
  83 #if DBG_LEVEL > 1
  84 #  define DBG2(f,x...)  DBG(f, ##x)
  85 #else
  86 #  define DBG2(f,x...)  ((void)0)
  87 #endif
  88 #if DBG_LEVEL > 2
  89 static void dump_iic_regs(const char* header, struct ibm_iic_private* dev)
  90 {
  91         volatile struct iic_regs __iomem *iic = dev->vaddr;
  92         printk(KERN_DEBUG "ibm-iic%d: %s\n", dev->idx, header);
  93         printk(KERN_DEBUG "  cntl     = 0x%02x, mdcntl = 0x%02x\n"
  94                KERN_DEBUG "  sts      = 0x%02x, extsts = 0x%02x\n"
  95                KERN_DEBUG "  clkdiv   = 0x%02x, xfrcnt = 0x%02x\n"
  96                KERN_DEBUG "  xtcntlss = 0x%02x, directcntl = 0x%02x\n",
  97                 in_8(&iic->cntl), in_8(&iic->mdcntl), in_8(&iic->sts),
  98                 in_8(&iic->extsts), in_8(&iic->clkdiv), in_8(&iic->xfrcnt),
  99                 in_8(&iic->xtcntlss), in_8(&iic->directcntl));
 100 }
 101 #  define DUMP_REGS(h,dev)      dump_iic_regs((h),(dev))
 102 #else
 103 #  define DUMP_REGS(h,dev)      ((void)0)
 104 #endif
 105
 106 /* Bus timings (in ns) for bit-banging */
 107 static struct i2c_timings {
 108         unsigned int hd_sta;
 109         unsigned int su_sto;
 110         unsigned int low;
 111         unsigned int high;
 112         unsigned int buf;
 113 } timings [] = {
 114 /* Standard mode (100 KHz) */
 115 {
 116         .hd_sta = 4000,
 117         .su_sto = 4000,
 118         .low    = 4700,
 119         .high   = 4000,
 120         .buf    = 4700,
 121 },
 122 /* Fast mode (400 KHz) */
 123 {
 124         .hd_sta = 600,
 125         .su_sto = 600,
 126         .low    = 1300,
 127         .high   = 600,
 128         .buf    = 1300,
 129 }};
 130
 131 /* Enable/disable interrupt generation */
 132 static inline void iic_interrupt_mode(struct ibm_iic_private* dev, int enable)
 133 {
 134         out_8(&dev->vaddr->intmsk, enable ? INTRMSK_EIMTC : 0);
 135 }
 136
 137 /*
 138  * Initialize IIC interface.
 139  */
 140 static void iic_dev_init(struct ibm_iic_private* dev)
 141 {
 142         volatile struct iic_regs __iomem *iic = dev->vaddr;
 143
 144         DBG("%d: init\n", dev->idx);
 145
 146         /* Clear master address */
 147         out_8(&iic->lmadr, 0);
 148         out_8(&iic->hmadr, 0);
 149
 150         /* Clear slave address */
 151         out_8(&iic->lsadr, 0);
 152         out_8(&iic->hsadr, 0);
 153
 154         /* Clear status & extended status */
 155         out_8(&iic->sts, STS_SCMP | STS_IRQA);
 156         out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD | EXTSTS_LA
 157                             | EXTSTS_ICT | EXTSTS_XFRA);
 158
 159         /* Set clock divider */
 160         out_8(&iic->clkdiv, dev->clckdiv);
 161
 162         /* Clear transfer count */
 163         out_8(&iic->xfrcnt, 0);
 164
 165         /* Clear extended control and status */
 166         out_8(&iic->xtcntlss, XTCNTLSS_SRC | XTCNTLSS_SRS | XTCNTLSS_SWC
 167                             | XTCNTLSS_SWS);
 168
 169         /* Clear control register */
 170         out_8(&iic->cntl, 0);
 171
 172         /* Enable interrupts if possible */
 173         iic_interrupt_mode(dev, dev->irq >= 0);
 174
 175         /* Set mode control */
 176         out_8(&iic->mdcntl, MDCNTL_FMDB | MDCNTL_EINT | MDCNTL_EUBS
 177                             | (dev->fast_mode ? MDCNTL_FSM : 0));
 178
 179         DUMP_REGS("iic_init", dev);
 180 }
 181
 182 /*
 183  * Reset IIC interface
 184  */
 185 static void iic_dev_reset(struct ibm_iic_private* dev)
 186 {
 187         volatile struct iic_regs __iomem *iic = dev->vaddr;
 188         int i;
 189         u8 dc;
 190
 191         DBG("%d: soft reset\n", dev->idx);
 192         DUMP_REGS("reset", dev);
 193
 194         /* Place chip in the reset state */
 195         out_8(&iic->xtcntlss, XTCNTLSS_SRST);
 196
 197         /* Check if bus is free */
 198         dc = in_8(&iic->directcntl);
 199         if (!DIRCTNL_FREE(dc)){
 200                 DBG("%d: trying to regain bus control\n", dev->idx);
 201
 202                 /* Try to set bus free state */
 203                 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
 204
 205                 /* Wait until we regain bus control */
 206                 for (i = 0; i < 100; ++i){
 207                         dc = in_8(&iic->directcntl);
 208                         if (DIRCTNL_FREE(dc))
 209                                 break;
 210
 211                         /* Toggle SCL line */
 212                         dc ^= DIRCNTL_SCC;
 213                         out_8(&iic->directcntl, dc);
 214                         udelay(10);
 215                         dc ^= DIRCNTL_SCC;
 216                         out_8(&iic->directcntl, dc);
 217
 218                         /* be nice */
 219                         cond_resched();
 220                 }
 221         }
 222
 223         /* Remove reset */
 224         out_8(&iic->xtcntlss, 0);
 225
 226         /* Reinitialize interface */
 227         iic_dev_init(dev);
 228 }
 229
 230 /*
 231  * Do 0-length transaction using bit-banging through IIC_DIRECTCNTL register.
 232  */
 233
 234 /* Wait for SCL and/or SDA to be high */
 235 static int iic_dc_wait(volatile struct iic_regs __iomem *iic, u8 mask)
 236 {
 237         unsigned long x = jiffies + HZ / 28 + 2;
 238         while ((in_8(&iic->directcntl) & mask) != mask){
 239                 if (unlikely(time_after(jiffies, x)))
 240                         return -1;
 241                 cond_resched();
 242         }
 243         return 0;
 244 }
 245
 246 static int iic_smbus_quick(struct ibm_iic_private* dev, const struct i2c_msg* p)
 247 {
 248         volatile struct iic_regs __iomem *iic = dev->vaddr;
 249         const struct i2c_timings* t = &timings[dev->fast_mode ? 1 : 0];
 250         u8 mask, v, sda;
 251         int i, res;
 252
 253         /* Only 7-bit addresses are supported */
 254         if (unlikely(p->flags & I2C_M_TEN)){
 255                 DBG("%d: smbus_quick - 10 bit addresses are not supported\n",
 256                         dev->idx);
 257                 return -EINVAL;
 258         }
 259
 260         DBG("%d: smbus_quick(0x%02x)\n", dev->idx, p->addr);
 261
 262         /* Reset IIC interface */
 263         out_8(&iic->xtcntlss, XTCNTLSS_SRST);
 264
 265         /* Wait for bus to become free */
 266         out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
 267         if (unlikely(iic_dc_wait(iic, DIRCNTL_MSDA | DIRCNTL_MSC)))
 268                 goto err;
 269         ndelay(t->buf);
 270
 271         /* START */
 272         out_8(&iic->directcntl, DIRCNTL_SCC);
 273         sda = 0;
 274         ndelay(t->hd_sta);
 275
 276         /* Send address */
 277         v = (u8)((p->addr << 1) | ((p->flags & I2C_M_RD) ? 1 : 0));
 278         for (i = 0, mask = 0x80; i < 8; ++i, mask >>= 1){
 279                 out_8(&iic->directcntl, sda);
 280                 ndelay(t->low / 2);
 281                 sda = (v & mask) ? DIRCNTL_SDAC : 0;
 282                 out_8(&iic->directcntl, sda);
 283                 ndelay(t->low / 2);
 284
 285                 out_8(&iic->directcntl, DIRCNTL_SCC | sda);
 286                 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
 287                         goto err;
 288                 ndelay(t->high);
 289         }
 290
 291         /* ACK */
 292         out_8(&iic->directcntl, sda);
 293         ndelay(t->low / 2);
 294         out_8(&iic->directcntl, DIRCNTL_SDAC);
 295         ndelay(t->low / 2);
 296         out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
 297         if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
 298                 goto err;
 299         res = (in_8(&iic->directcntl) & DIRCNTL_MSDA) ? -EREMOTEIO : 1;
 300         ndelay(t->high);
 301
 302         /* STOP */
 303         out_8(&iic->directcntl, 0);
 304         ndelay(t->low);
 305         out_8(&iic->directcntl, DIRCNTL_SCC);
 306         if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
 307                 goto err;
 308         ndelay(t->su_sto);
 309         out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
 310
 311         ndelay(t->buf);
 312
 313         DBG("%d: smbus_quick -> %s\n", dev->idx, res ? "NACK" : "ACK");
 314 out:
 315         /* Remove reset */
 316         out_8(&iic->xtcntlss, 0);
 317
 318         /* Reinitialize interface */
 319         iic_dev_init(dev);
 320
 321         return res;
 322 err:
 323         DBG("%d: smbus_quick - bus is stuck\n", dev->idx);
 324         res = -EREMOTEIO;
 325         goto out;
 326 }
 327
 328 /*
 329  * IIC interrupt handler
 330  */
 331 static irqreturn_t iic_handler(int irq, void *dev_id)
 332 {
 333         struct ibm_iic_private* dev = (struct ibm_iic_private*)dev_id;
 334         volatile struct iic_regs __iomem *iic = dev->vaddr;
 335
 336         DBG2("%d: irq handler, STS = 0x%02x, EXTSTS = 0x%02x\n",
 337              dev->idx, in_8(&iic->sts), in_8(&iic->extsts));
 338
 339         /* Acknowledge IRQ and wakeup iic_wait_for_tc */
 340         out_8(&iic->sts, STS_IRQA | STS_SCMP);
 341         wake_up_interruptible(&dev->wq);
 342
 343         return IRQ_HANDLED;
 344 }
 345
 346 /*
 347  * Get master transfer result and clear errors if any.
 348  * Returns the number of actually transferred bytes or error (<0)
 349  */
 350 static int iic_xfer_result(struct ibm_iic_private* dev)
 351 {
 352         volatile struct iic_regs __iomem *iic = dev->vaddr;
 353
 354         if (unlikely(in_8(&iic->sts) & STS_ERR)){
 355                 DBG("%d: xfer error, EXTSTS = 0x%02x\n", dev->idx,
 356                         in_8(&iic->extsts));
 357
 358                 /* Clear errors and possible pending IRQs */
 359                 out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD |
 360                         EXTSTS_LA | EXTSTS_ICT | EXTSTS_XFRA);
 361
 362                 /* Flush master data buffer */
 363                 out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB);
 364
 365                 /* Is bus free?
 366                  * If error happened during combined xfer
 367                  * IIC interface is usually stuck in some strange
 368                  * state, the only way out - soft reset.
 369                  */
 370                 if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
 371                         DBG("%d: bus is stuck, resetting\n", dev->idx);
 372                         iic_dev_reset(dev);
 373                 }
 374                 return -EREMOTEIO;
 375         }
 376         else
 377                 return in_8(&iic->xfrcnt) & XFRCNT_MTC_MASK;
 378 }
 379
 380 /*
 381  * Try to abort active transfer.
 382  */
 383 static void iic_abort_xfer(struct ibm_iic_private* dev)
 384 {
 385         volatile struct iic_regs __iomem *iic = dev->vaddr;
 386         unsigned long x;
 387
 388         DBG("%d: iic_abort_xfer\n", dev->idx);
 389
 390         out_8(&iic->cntl, CNTL_HMT);
 391
 392         /*
 393          * Wait for the abort command to complete.
 394          * It's not worth to be optimized, just poll (timeout >= 1 tick)
 395          */
 396         x = jiffies + 2;
 397         while ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
 398                 if (time_after(jiffies, x)){
 399                         DBG("%d: abort timeout, resetting...\n", dev->idx);
 400                         iic_dev_reset(dev);
 401                         return;
 402                 }
 403                 schedule();
 404         }
 405
 406         /* Just to clear errors */
 407         iic_xfer_result(dev);
 408 }
 409
 410 /*
 411  * Wait for master transfer to complete.
 412  * It puts current process to sleep until we get interrupt or timeout expires.
 413  * Returns the number of transferred bytes or error (<0)
 414  */
 415 static int iic_wait_for_tc(struct ibm_iic_private* dev){
 416
 417         volatile struct iic_regs __iomem *iic = dev->vaddr;
 418         int ret = 0;
 419
 420         if (dev->irq >= 0){
 421                 /* Interrupt mode */
 422                 ret = wait_event_interruptible_timeout(dev->wq,
 423                         !(in_8(&iic->sts) & STS_PT), dev->adap.timeout * HZ);
 424
 425                 if (unlikely(ret < 0))
 426                         DBG("%d: wait interrupted\n", dev->idx);
 427                 else if (unlikely(in_8(&iic->sts) & STS_PT)){
 428                         DBG("%d: wait timeout\n", dev->idx);
 429                         ret = -ETIMEDOUT;
 430                 }
 431         }
 432         else {
 433                 /* Polling mode */
 434                 unsigned long x = jiffies + dev->adap.timeout * HZ;
 435
 436                 while (in_8(&iic->sts) & STS_PT){
 437                         if (unlikely(time_after(jiffies, x))){
 438                                 DBG("%d: poll timeout\n", dev->idx);
 439                                 ret = -ETIMEDOUT;
 440                                 break;
 441                         }
 442
 443                         if (unlikely(signal_pending(current))){
 444                                 DBG("%d: poll interrupted\n", dev->idx);
 445                                 ret = -ERESTARTSYS;
 446                                 break;
 447                         }
 448                         schedule();
 449                 }
 450         }
 451
 452         if (unlikely(ret < 0))
 453                 iic_abort_xfer(dev);
 454         else
 455                 ret = iic_xfer_result(dev);
 456
 457         DBG2("%d: iic_wait_for_tc -> %d\n", dev->idx, ret);
 458
 459         return ret;
 460 }
 461
 462 /*
 463  * Low level master transfer routine
 464  */
 465 static int iic_xfer_bytes(struct ibm_iic_private* dev, struct i2c_msg* pm,
 466                           int combined_xfer)
 467 {
 468         volatile struct iic_regs __iomem *iic = dev->vaddr;
 469         char* buf = pm->buf;
 470         int i, j, loops, ret = 0;
 471         int len = pm->len;
 472
 473         u8 cntl = (in_8(&iic->cntl) & CNTL_AMD) | CNTL_PT;
 474         if (pm->flags & I2C_M_RD)
 475                 cntl |= CNTL_RW;
 476
 477         loops = (len + 3) / 4;
 478         for (i = 0; i < loops; ++i, len -= 4){
 479                 int count = len > 4 ? 4 : len;
 480                 u8 cmd = cntl | ((count - 1) << CNTL_TCT_SHIFT);
 481
 482                 if (!(cntl & CNTL_RW))
 483                         for (j = 0; j < count; ++j)
 484                                 out_8((void __iomem *)&iic->mdbuf, *buf++);
 485
 486                 if (i < loops - 1)
 487                         cmd |= CNTL_CHT;
 488                 else if (combined_xfer)
 489                         cmd |= CNTL_RPST;
 490
 491                 DBG2("%d: xfer_bytes, %d, CNTL = 0x%02x\n", dev->idx, count, cmd);
 492
 493                 /* Start transfer */
 494                 out_8(&iic->cntl, cmd);
 495
 496                 /* Wait for completion */
 497                 ret = iic_wait_for_tc(dev);
 498
 499                 if (unlikely(ret < 0))
 500                         break;
 501                 else if (unlikely(ret != count)){
 502                         DBG("%d: xfer_bytes, requested %d, transfered %d\n",
 503                                 dev->idx, count, ret);
 504
 505                         /* If it's not a last part of xfer, abort it */
 506                         if (combined_xfer || (i < loops - 1))
 507                                 iic_abort_xfer(dev);
 508
 509                         ret = -EREMOTEIO;
 510                         break;
 511                 }
 512
 513                 if (cntl & CNTL_RW)
 514                         for (j = 0; j < count; ++j)
 515                                 *buf++ = in_8((void __iomem *)&iic->mdbuf);
 516         }
 517
 518         return ret > 0 ? 0 : ret;
 519 }
 520
 521 /*
 522  * Set target slave address for master transfer
 523  */
 524 static inline void iic_address(struct ibm_iic_private* dev, struct i2c_msg* msg)
 525 {
 526         volatile struct iic_regs __iomem *iic = dev->vaddr;
 527         u16 addr = msg->addr;
 528
 529         DBG2("%d: iic_address, 0x%03x (%d-bit)\n", dev->idx,
 530                 addr, msg->flags & I2C_M_TEN ? 10 : 7);
 531
 532         if (msg->flags & I2C_M_TEN){
 533             out_8(&iic->cntl, CNTL_AMD);
 534             out_8(&iic->lmadr, addr);
 535             out_8(&iic->hmadr, 0xf0 | ((addr >> 7) & 0x06));
 536         }
 537         else {
 538             out_8(&iic->cntl, 0);
 539             out_8(&iic->lmadr, addr << 1);
 540         }
 541 }
 542
 543 static inline int iic_invalid_address(const struct i2c_msg* p)
 544 {
 545         return (p->addr > 0x3ff) || (!(p->flags & I2C_M_TEN) && (p->addr > 0x7f));
 546 }
 547
 548 static inline int iic_address_neq(const struct i2c_msg* p1,
 549                                   const struct i2c_msg* p2)
 550 {
 551         return (p1->addr != p2->addr)
 552                 || ((p1->flags & I2C_M_TEN) != (p2->flags & I2C_M_TEN));
 553 }
 554
 555 /*
 556  * Generic master transfer entrypoint.
 557  * Returns the number of processed messages or error (<0)
 558  */
 559 static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 560 {
 561         struct ibm_iic_private* dev = (struct ibm_iic_private*)(i2c_get_adapdata(adap));
 562         volatile struct iic_regs __iomem *iic = dev->vaddr;
 563         int i, ret = 0;
 564
 565         DBG2("%d: iic_xfer, %d msg(s)\n", dev->idx, num);
 566
 567         if (!num)
 568                 return 0;
 569
 570         /* Check the sanity of the passed messages.
 571          * Uhh, generic i2c layer is more suitable place for such code...
 572          */
 573         if (unlikely(iic_invalid_address(&msgs[0]))){
 574                 DBG("%d: invalid address 0x%03x (%d-bit)\n", dev->idx,
 575                         msgs[0].addr, msgs[0].flags & I2C_M_TEN ? 10 : 7);
 576                 return -EINVAL;
 577         }
 578         for (i = 0; i < num; ++i){
 579                 if (unlikely(msgs[i].len <= 0)){
 580                         if (num == 1 && !msgs[0].len){
 581                                 /* Special case for I2C_SMBUS_QUICK emulation.
 582                                  * IBM IIC doesn't support 0-length transactions
 583                                  * so we have to emulate them using bit-banging.
 584                                  */
 585                                 return iic_smbus_quick(dev, &msgs[0]);
 586                         }
 587                         DBG("%d: invalid len %d in msg[%d]\n", dev->idx,
 588                                 msgs[i].len, i);
 589                         return -EINVAL;
 590                 }
 591                 if (unlikely(iic_address_neq(&msgs[0], &msgs[i]))){
 592                         DBG("%d: invalid addr in msg[%d]\n", dev->idx, i);
 593                         return -EINVAL;
 594                 }
 595         }
 596
 597         /* Check bus state */
 598         if (unlikely((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE)){
 599                 DBG("%d: iic_xfer, bus is not free\n", dev->idx);
 600
 601                 /* Usually it means something serious has happend.
 602                  * We *cannot* have unfinished previous transfer
 603                  * so it doesn't make any sense to try to stop it.
 604                  * Probably we were not able to recover from the
 605                  * previous error.
 606                  * The only *reasonable* thing I can think of here
 607                  * is soft reset.  --ebs
 608                  */
 609                 iic_dev_reset(dev);
 610
 611                 if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
 612                         DBG("%d: iic_xfer, bus is still not free\n", dev->idx);
 613                         return -EREMOTEIO;
 614                 }
 615         }
 616         else {
 617                 /* Flush master data buffer (just in case) */
 618                 out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB);
 619         }
 620
 621         /* Load slave address */
 622         iic_address(dev, &msgs[0]);
 623
 624         /* Do real transfer */
 625         for (i = 0; i < num && !ret; ++i)
 626                 ret = iic_xfer_bytes(dev, &msgs[i], i < num - 1);
 627
 628         return ret < 0 ? ret : num;
 629 }
 630
 631 static u32 iic_func(struct i2c_adapter *adap)
 632 {
 633         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 634 }
 635
 636 static const struct i2c_algorithm iic_algo = {
 637         .master_xfer    = iic_xfer,
 638         .functionality  = iic_func
 639 };
 640
 641 /*
 642  * Calculates IICx_CLCKDIV value for a specific OPB clock frequency
 643  */
 644 static inline u8 iic_clckdiv(unsigned int opb)
 645 {
 646         /* Compatibility kludge, should go away after all cards
 647          * are fixed to fill correct value for opbfreq.
 648          * Previous driver version used hardcoded divider value 4,
 649          * it corresponds to OPB frequency from the range (40, 50] MHz
 650          */
 651         if (!opb){
 652                 printk(KERN_WARNING "ibm-iic: using compatibility value for OPB freq,"
 653                         " fix your board specific setup\n");
 654                 opb = 50000000;
 655         }
 656
 657         /* Convert to MHz */
 658         opb /= 1000000;
 659
 660         if (opb < 20 || opb > 150){
 661                 printk(KERN_WARNING "ibm-iic: invalid OPB clock frequency %u MHz\n",
 662                         opb);
 663                 opb = opb < 20 ? 20 : 150;
 664         }
 665         return (u8)((opb + 9) / 10 - 1);
 666 }
 667
 668 #ifdef CONFIG_IBM_OCP
 669 /*
 670  * Register single IIC interface
 671  */
 672 static int __devinit iic_probe(struct ocp_device *ocp){
 673
 674         struct ibm_iic_private* dev;
 675         struct i2c_adapter* adap;
 676         struct ocp_func_iic_data* iic_data = ocp->def->additions;
 677         int ret;
 678
 679         if (!iic_data)
 680                 printk(KERN_WARNING"ibm-iic%d: missing additional data!\n",
 681                         ocp->def->index);
 682
 683         if (!(dev = kzalloc(sizeof(*dev), GFP_KERNEL))) {
 684                 printk(KERN_ERR "ibm-iic%d: failed to allocate device data\n",
 685                         ocp->def->index);
 686                 return -ENOMEM;
 687         }
 688
 689         dev->idx = ocp->def->index;
 690         ocp_set_drvdata(ocp, dev);
 691
 692         if (!request_mem_region(ocp->def->paddr, sizeof(struct iic_regs),
 693                                 "ibm_iic")) {
 694                 ret = -EBUSY;
 695                 goto fail1;
 696         }
 697
 698         if (!(dev->vaddr = ioremap(ocp->def->paddr, sizeof(struct iic_regs)))){
 699                 printk(KERN_ERR "ibm-iic%d: failed to ioremap device registers\n",
 700                         dev->idx);
 701                 ret = -ENXIO;
 702                 goto fail2;
 703         }
 704
 705         init_waitqueue_head(&dev->wq);
 706
 707         dev->irq = iic_force_poll ? -1 : ocp->def->irq;
 708         if (dev->irq >= 0){
 709                 /* Disable interrupts until we finish initialization,
 710                    assumes level-sensitive IRQ setup...
 711                  */
 712                 iic_interrupt_mode(dev, 0);
 713                 if (request_irq(dev->irq, iic_handler, 0, "IBM IIC", dev)){
 714                         printk(KERN_ERR "ibm-iic%d: request_irq %d failed\n",
 715                                 dev->idx, dev->irq);
 716                         /* Fallback to the polling mode */
 717                         dev->irq = -1;
 718                 }
 719         }
 720
 721         if (dev->irq < 0)
 722                 printk(KERN_WARNING "ibm-iic%d: using polling mode\n",
 723                         dev->idx);
 724
 725         /* Board specific settings */
 726         dev->fast_mode = iic_force_fast ? 1 : (iic_data ? iic_data->fast_mode : 0);
 727
 728         /* clckdiv is the same for *all* IIC interfaces,
 729          * but I'd rather make a copy than introduce another global. --ebs
 730          */
 731         dev->clckdiv = iic_clckdiv(ocp_sys_info.opb_bus_freq);
 732         DBG("%d: clckdiv = %d\n", dev->idx, dev->clckdiv);
 733
 734         /* Initialize IIC interface */
 735         iic_dev_init(dev);
 736
 737         /* Register it with i2c layer */
 738         adap = &dev->adap;
 739         adap->dev.parent = &ocp->dev;
 740         strcpy(adap->name, "IBM IIC");
 741         i2c_set_adapdata(adap, dev);
 742         adap->id = I2C_HW_OCP;
 743         adap->class = I2C_CLASS_HWMON;
 744         adap->algo = &iic_algo;
 745         adap->client_register = NULL;
 746         adap->client_unregister = NULL;
 747         adap->timeout = 1;
 748
 749         /*
 750          * If "dev->idx" is negative we consider it as zero.
 751          * The reason to do so is to avoid sysfs names that only make
 752          * sense when there are multiple adapters.
 753          */
 754         adap->nr = dev->idx >= 0 ? dev->idx : 0;
 755
 756         if ((ret = i2c_add_numbered_adapter(adap)) < 0) {
 757                 printk(KERN_ERR "ibm-iic%d: failed to register i2c adapter\n",
 758                         dev->idx);
 759                 goto fail;
 760         }
 761
 762         printk(KERN_INFO "ibm-iic%d: using %s mode\n", dev->idx,
 763                 dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)");
 764
 765         return 0;
 766
 767 fail:
 768         if (dev->irq >= 0){
 769                 iic_interrupt_mode(dev, 0);
 770                 free_irq(dev->irq, dev);
 771         }
 772
 773         iounmap(dev->vaddr);
 774 fail2:
 775         release_mem_region(ocp->def->paddr, sizeof(struct iic_regs));
 776 fail1:
 777         ocp_set_drvdata(ocp, NULL);
 778         kfree(dev);
 779         return ret;
 780 }
 781
 782 /*
 783  * Cleanup initialized IIC interface
 784  */
 785 static void __devexit iic_remove(struct ocp_device *ocp)
 786 {
 787         struct ibm_iic_private* dev = (struct ibm_iic_private*)ocp_get_drvdata(ocp);
 788         BUG_ON(dev == NULL);
 789         if (i2c_del_adapter(&dev->adap)){
 790                 printk(KERN_ERR "ibm-iic%d: failed to delete i2c adapter :(\n",
 791                         dev->idx);
 792                 /* That's *very* bad, just shutdown IRQ ... */
 793                 if (dev->irq >= 0){
 794                     iic_interrupt_mode(dev, 0);
 795                     free_irq(dev->irq, dev);
 796                     dev->irq = -1;
 797                 }
 798         } else {
 799                 if (dev->irq >= 0){
 800                     iic_interrupt_mode(dev, 0);
 801                     free_irq(dev->irq, dev);
 802                 }
 803                 iounmap(dev->vaddr);
 804                 release_mem_region(ocp->def->paddr, sizeof(struct iic_regs));
 805                 kfree(dev);
 806         }
 807 }
 808
 809 static struct ocp_device_id ibm_iic_ids[] __devinitdata =
 810 {
 811         { .vendor = OCP_VENDOR_IBM, .function = OCP_FUNC_IIC },
 812         { .vendor = OCP_VENDOR_INVALID }
 813 };
 814
 815 MODULE_DEVICE_TABLE(ocp, ibm_iic_ids);
 816
 817 static struct ocp_driver ibm_iic_driver =
 818 {
 819         .name           = "iic",
 820         .id_table       = ibm_iic_ids,
 821         .probe          = iic_probe,
 822         .remove         = __devexit_p(iic_remove),
 823 #if defined(CONFIG_PM)
 824         .suspend        = NULL,
 825         .resume         = NULL,
 826 #endif
 827 };
 828
 829 static int __init iic_init(void)
 830 {
 831         printk(KERN_INFO "IBM IIC driver v" DRIVER_VERSION "\n");
 832         return ocp_register_driver(&ibm_iic_driver);
 833 }
 834
 835 static void __exit iic_exit(void)
 836 {
 837         ocp_unregister_driver(&ibm_iic_driver);
 838 }
 839
 840 #else  /* !CONFIG_IBM_OCP */
 841
 842 static int __devinit iic_request_irq(struct of_device *ofdev,
 843                                      struct ibm_iic_private *dev)
 844 {
 845         struct device_node *np = ofdev->node;
 846         int irq;
 847
 848         if (iic_force_poll)
 849                 return NO_IRQ;
 850
 851         irq = irq_of_parse_and_map(np, 0);
 852         if (irq == NO_IRQ) {
 853                 dev_err(&ofdev->dev, "irq_of_parse_and_map failed\n");
 854                 return NO_IRQ;
 855         }
 856
 857         /* Disable interrupts until we finish initialization, assumes
 858          *  level-sensitive IRQ setup...
 859          */
 860         iic_interrupt_mode(dev, 0);
 861         if (request_irq(irq, iic_handler, 0, "IBM IIC", dev)) {
 862                 dev_err(&ofdev->dev, "request_irq %d failed\n", irq);
 863                 /* Fallback to the polling mode */
 864                 return NO_IRQ;
 865         }
 866
 867         return irq;
 868 }
 869
 870 /*
 871  * Register single IIC interface
 872  */
 873 static int __devinit iic_probe(struct of_device *ofdev,
 874                                const struct of_device_id *match)
 875 {
 876         struct device_node *np = ofdev->node;
 877         struct ibm_iic_private *dev;
 878         struct i2c_adapter *adap;
 879         const u32 *indexp, *freq;
 880         int ret;
 881
 882         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 883         if (!dev) {
 884                 dev_err(&ofdev->dev, "failed to allocate device data\n");
 885                 return -ENOMEM;
 886         }
 887
 888         dev_set_drvdata(&ofdev->dev, dev);
 889
 890         indexp = of_get_property(np, "index", NULL);
 891         if (!indexp) {
 892                 dev_err(&ofdev->dev, "no index specified\n");
 893                 ret = -EINVAL;
 894                 goto error_cleanup;
 895         }
 896         dev->idx = *indexp;
 897
 898         dev->vaddr = of_iomap(np, 0);
 899         if (dev->vaddr == NULL) {
 900                 dev_err(&ofdev->dev, "failed to iomap device\n");
 901                 ret = -ENXIO;
 902                 goto error_cleanup;
 903         }
 904
 905         init_waitqueue_head(&dev->wq);
 906
 907         dev->irq = iic_request_irq(ofdev, dev);
 908         if (dev->irq == NO_IRQ)
 909                 dev_warn(&ofdev->dev, "using polling mode\n");
 910
 911         /* Board specific settings */
 912         if (iic_force_fast || of_get_property(np, "fast-mode", NULL))
 913                 dev->fast_mode = 1;
 914
 915         freq = of_get_property(np, "clock-frequency", NULL);
 916         if (freq == NULL) {
 917                 freq = of_get_property(np->parent, "clock-frequency", NULL);
 918                 if (freq == NULL) {
 919                         dev_err(&ofdev->dev, "Unable to get bus frequency\n");
 920                         ret = -EINVAL;
 921                         goto error_cleanup;
 922                 }
 923         }
 924
 925         dev->clckdiv = iic_clckdiv(*freq);
 926         dev_dbg(&ofdev->dev, "clckdiv = %d\n", dev->clckdiv);
 927
 928         /* Initialize IIC interface */
 929         iic_dev_init(dev);
 930
 931         /* Register it with i2c layer */
 932         adap = &dev->adap;
 933         adap->dev.parent = &ofdev->dev;
 934         strlcpy(adap->name, "IBM IIC", sizeof(adap->name));
 935         i2c_set_adapdata(adap, dev);
 936         adap->id = I2C_HW_OCP;
 937         adap->class = I2C_CLASS_HWMON;
 938         adap->algo = &iic_algo;
 939         adap->timeout = 1;
 940         adap->nr = dev->idx;
 941
 942         ret = i2c_add_numbered_adapter(adap);
 943         if (ret  < 0) {
 944                 dev_err(&ofdev->dev, "failed to register i2c adapter\n");
 945                 goto error_cleanup;
 946         }
 947
 948         dev_info(&ofdev->dev, "using %s mode\n",
 949                  dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)");
 950
 951         return 0;
 952
 953 error_cleanup:
 954         if (dev->irq != NO_IRQ) {
 955                 iic_interrupt_mode(dev, 0);
 956                 free_irq(dev->irq, dev);
 957         }
 958
 959         if (dev->vaddr)
 960                 iounmap(dev->vaddr);
 961
 962         dev_set_drvdata(&ofdev->dev, NULL);
 963         kfree(dev);
 964         return ret;
 965 }
 966
 967 /*
 968  * Cleanup initialized IIC interface
 969  */
 970 static int __devexit iic_remove(struct of_device *ofdev)
 971 {
 972         struct ibm_iic_private *dev = dev_get_drvdata(&ofdev->dev);
 973
 974         dev_set_drvdata(&ofdev->dev, NULL);
 975
 976         i2c_del_adapter(&dev->adap);
 977
 978         if (dev->irq != NO_IRQ) {
 979                 iic_interrupt_mode(dev, 0);
 980                 free_irq(dev->irq, dev);
 981         }
 982
 983         iounmap(dev->vaddr);
 984         kfree(dev);
 985
 986         return 0;
 987 }
 988
 989 static const struct of_device_id ibm_iic_match[] = {
 990         { .compatible = "ibm,iic-405ex", },
 991         { .compatible = "ibm,iic-405gp", },
 992         { .compatible = "ibm,iic-440gp", },
 993         { .compatible = "ibm,iic-440gpx", },
 994         { .compatible = "ibm,iic-440grx", },
 995         {}
 996 };
 997
 998 static struct of_platform_driver ibm_iic_driver = {
 999         .name   = "ibm-iic",
1000         .match_table = ibm_iic_match,
1001         .probe  = iic_probe,
1002         .remove = __devexit_p(iic_remove),
1003 };
1004
1005 static int __init iic_init(void)
1006 {
1007         return of_register_platform_driver(&ibm_iic_driver);
1008 }
1009
1010 static void __exit iic_exit(void)
1011 {
1012         of_unregister_platform_driver(&ibm_iic_driver);
1013 }
1014 #endif /* CONFIG_IBM_OCP */
1015
1016 module_init(iic_init);
1017 module_exit(iic_exit);