drivers/i2c/busses/i2c-pxa.c

   1 /*
   2  *  i2c_adap_pxa.c
   3  *
   4  *  I2C adapter for the PXA I2C bus access.
   5  *
   6  *  Copyright (C) 2002 Intrinsyc Software Inc.
   7  *  Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2 as
  11  *  published by the Free Software Foundation.
  12  *
  13  *  History:
  14  *    Apr 2002: Initial version [CS]
  15  *    Jun 2002: Properly seperated algo/adap [FB]
  16  *    Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
  17  *    Jan 2003: added limited signal handling [Kai-Uwe Bloem]
  18  *    Sep 2004: Major rework to ensure efficient bus handling [RMK]
  19  *    Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
  20  *    Feb 2005: Rework slave mode handling [RMK]
  21  */
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/i2c.h>
  25 #include <linux/i2c-id.h>
  26 #include <linux/init.h>
  27 #include <linux/time.h>
  28 #include <linux/sched.h>
  29 #include <linux/delay.h>
  30 #include <linux/errno.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/i2c-pxa.h>
  33 #include <linux/platform_device.h>
  34
  35 #include <asm/hardware.h>
  36 #include <asm/irq.h>
  37 #include <asm/io.h>
  38 #include <asm/arch/i2c.h>
  39 #include <asm/arch/pxa-regs.h>
  40
  41 struct pxa_i2c {
  42         spinlock_t              lock;
  43         wait_queue_head_t       wait;
  44         struct i2c_msg          *msg;
  45         unsigned int            msg_num;
  46         unsigned int            msg_idx;
  47         unsigned int            msg_ptr;
  48         unsigned int            slave_addr;
  49
  50         struct i2c_adapter      adap;
  51 #ifdef CONFIG_I2C_PXA_SLAVE
  52         struct i2c_slave_client *slave;
  53 #endif
  54
  55         unsigned int            irqlogidx;
  56         u32                     isrlog[32];
  57         u32                     icrlog[32];
  58
  59         void __iomem            *reg_base;
  60
  61         unsigned long           iobase;
  62         unsigned long           iosize;
  63
  64         int                     irq;
  65 };
  66
  67 #define _IBMR(i2c)      ((i2c)->reg_base + 0)
  68 #define _IDBR(i2c)      ((i2c)->reg_base + 8)
  69 #define _ICR(i2c)       ((i2c)->reg_base + 0x10)
  70 #define _ISR(i2c)       ((i2c)->reg_base + 0x18)
  71 #define _ISAR(i2c)      ((i2c)->reg_base + 0x20)
  72
  73 /*
  74  * I2C Slave mode address
  75  */
  76 #define I2C_PXA_SLAVE_ADDR      0x1
  77
  78 #ifdef DEBUG
  79
  80 struct bits {
  81         u32     mask;
  82         const char *set;
  83         const char *unset;
  84 };
  85 #define BIT(m, s, u)    { .mask = m, .set = s, .unset = u }
  86
  87 static inline void
  88 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
  89 {
  90         printk("%s %08x: ", prefix, val);
  91         while (num--) {
  92                 const char *str = val & bits->mask ? bits->set : bits->unset;
  93                 if (str)
  94                         printk("%s ", str);
  95                 bits++;
  96         }
  97 }
  98
  99 static const struct bits isr_bits[] = {
 100         BIT(ISR_RWM,    "RX",           "TX"),
 101         BIT(ISR_ACKNAK, "NAK",          "ACK"),
 102         BIT(ISR_UB,     "Bsy",          "Rdy"),
 103         BIT(ISR_IBB,    "BusBsy",       "BusRdy"),
 104         BIT(ISR_SSD,    "SlaveStop",    NULL),
 105         BIT(ISR_ALD,    "ALD",          NULL),
 106         BIT(ISR_ITE,    "TxEmpty",      NULL),
 107         BIT(ISR_IRF,    "RxFull",       NULL),
 108         BIT(ISR_GCAD,   "GenCall",      NULL),
 109         BIT(ISR_SAD,    "SlaveAddr",    NULL),
 110         BIT(ISR_BED,    "BusErr",       NULL),
 111 };
 112
 113 static void decode_ISR(unsigned int val)
 114 {
 115         decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
 116         printk("\n");
 117 }
 118
 119 static const struct bits icr_bits[] = {
 120         BIT(ICR_START,  "START",        NULL),
 121         BIT(ICR_STOP,   "STOP",         NULL),
 122         BIT(ICR_ACKNAK, "ACKNAK",       NULL),
 123         BIT(ICR_TB,     "TB",           NULL),
 124         BIT(ICR_MA,     "MA",           NULL),
 125         BIT(ICR_SCLE,   "SCLE",         "scle"),
 126         BIT(ICR_IUE,    "IUE",          "iue"),
 127         BIT(ICR_GCD,    "GCD",          NULL),
 128         BIT(ICR_ITEIE,  "ITEIE",        NULL),
 129         BIT(ICR_IRFIE,  "IRFIE",        NULL),
 130         BIT(ICR_BEIE,   "BEIE",         NULL),
 131         BIT(ICR_SSDIE,  "SSDIE",        NULL),
 132         BIT(ICR_ALDIE,  "ALDIE",        NULL),
 133         BIT(ICR_SADIE,  "SADIE",        NULL),
 134         BIT(ICR_UR,     "UR",           "ur"),
 135 };
 136
 137 static void decode_ICR(unsigned int val)
 138 {
 139         decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
 140         printk("\n");
 141 }
 142
 143 static unsigned int i2c_debug = DEBUG;
 144
 145 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
 146 {
 147         dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
 148                 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 149 }
 150
 151 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __FUNCTION__)
 152 #else
 153 #define i2c_debug       0
 154
 155 #define show_state(i2c) do { } while (0)
 156 #define decode_ISR(val) do { } while (0)
 157 #define decode_ICR(val) do { } while (0)
 158 #endif
 159
 160 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
 161
 162 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
 163
 164 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
 165 {
 166         unsigned int i;
 167         printk("i2c: error: %s\n", why);
 168         printk("i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
 169                 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
 170         printk("i2c: ICR: %08x ISR: %08x\n"
 171                "i2c: log: ", readl(_ICR(i2c)), readl(_ISR(i2c)));
 172         for (i = 0; i < i2c->irqlogidx; i++)
 173                 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
 174         printk("\n");
 175 }
 176
 177 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
 178 {
 179         return !(readl(_ICR(i2c)) & ICR_SCLE);
 180 }
 181
 182 static void i2c_pxa_abort(struct pxa_i2c *i2c)
 183 {
 184         unsigned long timeout = jiffies + HZ/4;
 185
 186         if (i2c_pxa_is_slavemode(i2c)) {
 187                 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
 188                 return;
 189         }
 190
 191         while (time_before(jiffies, timeout) && (readl(_IBMR(i2c)) & 0x1) == 0) {
 192                 unsigned long icr = readl(_ICR(i2c));
 193
 194                 icr &= ~ICR_START;
 195                 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
 196
 197                 writel(icr, _ICR(i2c));
 198
 199                 show_state(i2c);
 200
 201                 msleep(1);
 202         }
 203
 204         writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
 205                _ICR(i2c));
 206 }
 207
 208 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
 209 {
 210         int timeout = DEF_TIMEOUT;
 211
 212         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
 213                 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
 214                         timeout += 4;
 215
 216                 msleep(2);
 217                 show_state(i2c);
 218         }
 219
 220         if (timeout <= 0)
 221                 show_state(i2c);
 222
 223         return timeout <= 0 ? I2C_RETRY : 0;
 224 }
 225
 226 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
 227 {
 228         unsigned long timeout = jiffies + HZ*4;
 229
 230         while (time_before(jiffies, timeout)) {
 231                 if (i2c_debug > 1)
 232                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 233                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 234
 235                 if (readl(_ISR(i2c)) & ISR_SAD) {
 236                         if (i2c_debug > 0)
 237                                 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
 238                         goto out;
 239                 }
 240
 241                 /* wait for unit and bus being not busy, and we also do a
 242                  * quick check of the i2c lines themselves to ensure they've
 243                  * gone high...
 244                  */
 245                 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
 246                         if (i2c_debug > 0)
 247                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
 248                         return 1;
 249                 }
 250
 251                 msleep(1);
 252         }
 253
 254         if (i2c_debug > 0)
 255                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
 256  out:
 257         return 0;
 258 }
 259
 260 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
 261 {
 262         if (i2c_debug)
 263                 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
 264
 265         if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
 266                 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
 267                 if (!i2c_pxa_wait_master(i2c)) {
 268                         dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
 269                         return I2C_RETRY;
 270                 }
 271         }
 272
 273         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
 274         return 0;
 275 }
 276
 277 #ifdef CONFIG_I2C_PXA_SLAVE
 278 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
 279 {
 280         unsigned long timeout = jiffies + HZ*1;
 281
 282         /* wait for stop */
 283
 284         show_state(i2c);
 285
 286         while (time_before(jiffies, timeout)) {
 287                 if (i2c_debug > 1)
 288                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 289                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 290
 291                 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
 292                     (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
 293                     (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
 294                         if (i2c_debug > 1)
 295                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
 296                         return 1;
 297                 }
 298
 299                 msleep(1);
 300         }
 301
 302         if (i2c_debug > 0)
 303                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
 304         return 0;
 305 }
 306
 307 /*
 308  * clear the hold on the bus, and take of anything else
 309  * that has been configured
 310  */
 311 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
 312 {
 313         show_state(i2c);
 314
 315         if (errcode < 0) {
 316                 udelay(100);   /* simple delay */
 317         } else {
 318                 /* we need to wait for the stop condition to end */
 319
 320                 /* if we where in stop, then clear... */
 321                 if (readl(_ICR(i2c)) & ICR_STOP) {
 322                         udelay(100);
 323                         writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
 324                 }
 325
 326                 if (!i2c_pxa_wait_slave(i2c)) {
 327                         dev_err(&i2c->adap.dev, "%s: wait timedout\n",
 328                                 __func__);
 329                         return;
 330                 }
 331         }
 332
 333         writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
 334         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 335
 336         if (i2c_debug) {
 337                 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
 338                 decode_ICR(readl(_ICR(i2c)));
 339         }
 340 }
 341 #else
 342 #define i2c_pxa_set_slave(i2c, err)     do { } while (0)
 343 #endif
 344
 345 static void i2c_pxa_reset(struct pxa_i2c *i2c)
 346 {
 347         pr_debug("Resetting I2C Controller Unit\n");
 348
 349         /* abort any transfer currently under way */
 350         i2c_pxa_abort(i2c);
 351
 352         /* reset according to 9.8 */
 353         writel(ICR_UR, _ICR(i2c));
 354         writel(I2C_ISR_INIT, _ISR(i2c));
 355         writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
 356
 357         writel(i2c->slave_addr, _ISAR(i2c));
 358
 359         /* set control register values */
 360         writel(I2C_ICR_INIT, _ICR(i2c));
 361
 362 #ifdef CONFIG_I2C_PXA_SLAVE
 363         dev_info(&i2c->adap.dev, "Enabling slave mode\n");
 364         writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
 365 #endif
 366
 367         i2c_pxa_set_slave(i2c, 0);
 368
 369         /* enable unit */
 370         writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
 371         udelay(100);
 372 }
 373
 374
 375 #ifdef CONFIG_I2C_PXA_SLAVE
 376 /*
 377  * PXA I2C Slave mode
 378  */
 379
 380 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
 381 {
 382         if (isr & ISR_BED) {
 383                 /* what should we do here? */
 384         } else {
 385                 int ret = 0;
 386
 387                 if (i2c->slave != NULL)
 388                         ret = i2c->slave->read(i2c->slave->data);
 389
 390                 writel(ret, _IDBR(i2c));
 391                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));   /* allow next byte */
 392         }
 393 }
 394
 395 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
 396 {
 397         unsigned int byte = readl(_IDBR(i2c));
 398
 399         if (i2c->slave != NULL)
 400                 i2c->slave->write(i2c->slave->data, byte);
 401
 402         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 403 }
 404
 405 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
 406 {
 407         int timeout;
 408
 409         if (i2c_debug > 0)
 410                 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
 411                        (isr & ISR_RWM) ? 'r' : 't');
 412
 413         if (i2c->slave != NULL)
 414                 i2c->slave->event(i2c->slave->data,
 415                                  (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
 416
 417         /*
 418          * slave could interrupt in the middle of us generating a
 419          * start condition... if this happens, we'd better back off
 420          * and stop holding the poor thing up
 421          */
 422         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
 423         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 424
 425         timeout = 0x10000;
 426
 427         while (1) {
 428                 if ((readl(_IBMR(i2c)) & 2) == 2)
 429                         break;
 430
 431                 timeout--;
 432
 433                 if (timeout <= 0) {
 434                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
 435                         break;
 436                 }
 437         }
 438
 439         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 440 }
 441
 442 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
 443 {
 444         if (i2c_debug > 2)
 445                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
 446
 447         if (i2c->slave != NULL)
 448                 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
 449
 450         if (i2c_debug > 2)
 451                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
 452
 453         /*
 454          * If we have a master-mode message waiting,
 455          * kick it off now that the slave has completed.
 456          */
 457         if (i2c->msg)
 458                 i2c_pxa_master_complete(i2c, I2C_RETRY);
 459 }
 460 #else
 461 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
 462 {
 463         if (isr & ISR_BED) {
 464                 /* what should we do here? */
 465         } else {
 466                 writel(0, _IDBR(i2c));
 467                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 468         }
 469 }
 470
 471 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
 472 {
 473         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
 474 }
 475
 476 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
 477 {
 478         int timeout;
 479
 480         /*
 481          * slave could interrupt in the middle of us generating a
 482          * start condition... if this happens, we'd better back off
 483          * and stop holding the poor thing up
 484          */
 485         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
 486         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
 487
 488         timeout = 0x10000;
 489
 490         while (1) {
 491                 if ((readl(_IBMR(i2c)) & 2) == 2)
 492                         break;
 493
 494                 timeout--;
 495
 496                 if (timeout <= 0) {
 497                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
 498                         break;
 499                 }
 500         }
 501
 502         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 503 }
 504
 505 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
 506 {
 507         if (i2c->msg)
 508                 i2c_pxa_master_complete(i2c, I2C_RETRY);
 509 }
 510 #endif
 511
 512 /*
 513  * PXA I2C Master mode
 514  */
 515
 516 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
 517 {
 518         unsigned int addr = (msg->addr & 0x7f) << 1;
 519
 520         if (msg->flags & I2C_M_RD)
 521                 addr |= 1;
 522
 523         return addr;
 524 }
 525
 526 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
 527 {
 528         u32 icr;
 529
 530         /*
 531          * Step 1: target slave address into IDBR
 532          */
 533         writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
 534
 535         /*
 536          * Step 2: initiate the write.
 537          */
 538         icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
 539         writel(icr | ICR_START | ICR_TB, _ICR(i2c));
 540 }
 541
 542 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
 543 {
 544         u32 icr;
 545
 546         /*
 547          * Clear the STOP and ACK flags
 548          */
 549         icr = readl(_ICR(i2c));
 550         icr &= ~(ICR_STOP | ICR_ACKNAK);
 551         writel(icr, _IRC(i2c));
 552 }
 553
 554 /*
 555  * We are protected by the adapter bus mutex.
 556  */
 557 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 558 {
 559         long timeout;
 560         int ret;
 561
 562         /*
 563          * Wait for the bus to become free.
 564          */
 565         ret = i2c_pxa_wait_bus_not_busy(i2c);
 566         if (ret) {
 567                 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
 568                 goto out;
 569         }
 570
 571         /*
 572          * Set master mode.
 573          */
 574         ret = i2c_pxa_set_master(i2c);
 575         if (ret) {
 576                 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
 577                 goto out;
 578         }
 579
 580         spin_lock_irq(&i2c->lock);
 581
 582         i2c->msg = msg;
 583         i2c->msg_num = num;
 584         i2c->msg_idx = 0;
 585         i2c->msg_ptr = 0;
 586         i2c->irqlogidx = 0;
 587
 588         i2c_pxa_start_message(i2c);
 589
 590         spin_unlock_irq(&i2c->lock);
 591
 592         /*
 593          * The rest of the processing occurs in the interrupt handler.
 594          */
 595         timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
 596         i2c_pxa_stop_message(i2c);
 597
 598         /*
 599          * We place the return code in i2c->msg_idx.
 600          */
 601         ret = i2c->msg_idx;
 602
 603         if (timeout == 0)
 604                 i2c_pxa_scream_blue_murder(i2c, "timeout");
 605
 606  out:
 607         return ret;
 608 }
 609
 610 /*
 611  * i2c_pxa_master_complete - complete the message and wake up.
 612  */
 613 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
 614 {
 615         i2c->msg_ptr = 0;
 616         i2c->msg = NULL;
 617         i2c->msg_idx ++;
 618         i2c->msg_num = 0;
 619         if (ret)
 620                 i2c->msg_idx = ret;
 621         wake_up(&i2c->wait);
 622 }
 623
 624 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
 625 {
 626         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
 627
 628  again:
 629         /*
 630          * If ISR_ALD is set, we lost arbitration.
 631          */
 632         if (isr & ISR_ALD) {
 633                 /*
 634                  * Do we need to do anything here?  The PXA docs
 635                  * are vague about what happens.
 636                  */
 637                 i2c_pxa_scream_blue_murder(i2c, "ALD set");
 638
 639                 /*
 640                  * We ignore this error.  We seem to see spurious ALDs
 641                  * for seemingly no reason.  If we handle them as I think
 642                  * they should, we end up causing an I2C error, which
 643                  * is painful for some systems.
 644                  */
 645                 return; /* ignore */
 646         }
 647
 648         if (isr & ISR_BED) {
 649                 int ret = BUS_ERROR;
 650
 651                 /*
 652                  * I2C bus error - either the device NAK'd us, or
 653                  * something more serious happened.  If we were NAK'd
 654                  * on the initial address phase, we can retry.
 655                  */
 656                 if (isr & ISR_ACKNAK) {
 657                         if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
 658                                 ret = I2C_RETRY;
 659                         else
 660                                 ret = XFER_NAKED;
 661                 }
 662                 i2c_pxa_master_complete(i2c, ret);
 663         } else if (isr & ISR_RWM) {
 664                 /*
 665                  * Read mode.  We have just sent the address byte, and
 666                  * now we must initiate the transfer.
 667                  */
 668                 if (i2c->msg_ptr == i2c->msg->len - 1 &&
 669                     i2c->msg_idx == i2c->msg_num - 1)
 670                         icr |= ICR_STOP | ICR_ACKNAK;
 671
 672                 icr |= ICR_ALDIE | ICR_TB;
 673         } else if (i2c->msg_ptr < i2c->msg->len) {
 674                 /*
 675                  * Write mode.  Write the next data byte.
 676                  */
 677                 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
 678
 679                 icr |= ICR_ALDIE | ICR_TB;
 680
 681                 /*
 682                  * If this is the last byte of the last message, send
 683                  * a STOP.
 684                  */
 685                 if (i2c->msg_ptr == i2c->msg->len &&
 686                     i2c->msg_idx == i2c->msg_num - 1)
 687                         icr |= ICR_STOP;
 688         } else if (i2c->msg_idx < i2c->msg_num - 1) {
 689                 /*
 690                  * Next segment of the message.
 691                  */
 692                 i2c->msg_ptr = 0;
 693                 i2c->msg_idx ++;
 694                 i2c->msg++;
 695
 696                 /*
 697                  * If we aren't doing a repeated start and address,
 698                  * go back and try to send the next byte.  Note that
 699                  * we do not support switching the R/W direction here.
 700                  */
 701                 if (i2c->msg->flags & I2C_M_NOSTART)
 702                         goto again;
 703
 704                 /*
 705                  * Write the next address.
 706                  */
 707                 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
 708
 709                 /*
 710                  * And trigger a repeated start, and send the byte.
 711                  */
 712                 icr &= ~ICR_ALDIE;
 713                 icr |= ICR_START | ICR_TB;
 714         } else {
 715                 if (i2c->msg->len == 0) {
 716                         /*
 717                          * Device probes have a message length of zero
 718                          * and need the bus to be reset before it can
 719                          * be used again.
 720                          */
 721                         i2c_pxa_reset(i2c);
 722                 }
 723                 i2c_pxa_master_complete(i2c, 0);
 724         }
 725
 726         i2c->icrlog[i2c->irqlogidx-1] = icr;
 727
 728         writel(icr, _ICR(i2c));
 729         show_state(i2c);
 730 }
 731
 732 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
 733 {
 734         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
 735
 736         /*
 737          * Read the byte.
 738          */
 739         i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
 740
 741         if (i2c->msg_ptr < i2c->msg->len) {
 742                 /*
 743                  * If this is the last byte of the last
 744                  * message, send a STOP.
 745                  */
 746                 if (i2c->msg_ptr == i2c->msg->len - 1)
 747                         icr |= ICR_STOP | ICR_ACKNAK;
 748
 749                 icr |= ICR_ALDIE | ICR_TB;
 750         } else {
 751                 i2c_pxa_master_complete(i2c, 0);
 752         }
 753
 754         i2c->icrlog[i2c->irqlogidx-1] = icr;
 755
 756         writel(icr, _ICR(i2c));
 757 }
 758
 759 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
 760 {
 761         struct pxa_i2c *i2c = dev_id;
 762         u32 isr = readl(_ISR(i2c));
 763
 764         if (i2c_debug > 2 && 0) {
 765                 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 766                         __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
 767                 decode_ISR(isr);
 768         }
 769
 770         if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
 771                 i2c->isrlog[i2c->irqlogidx++] = isr;
 772
 773         show_state(i2c);
 774
 775         /*
 776          * Always clear all pending IRQs.
 777          */
 778         writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
 779
 780         if (isr & ISR_SAD)
 781                 i2c_pxa_slave_start(i2c, isr);
 782         if (isr & ISR_SSD)
 783                 i2c_pxa_slave_stop(i2c);
 784
 785         if (i2c_pxa_is_slavemode(i2c)) {
 786                 if (isr & ISR_ITE)
 787                         i2c_pxa_slave_txempty(i2c, isr);
 788                 if (isr & ISR_IRF)
 789                         i2c_pxa_slave_rxfull(i2c, isr);
 790         } else if (i2c->msg) {
 791                 if (isr & ISR_ITE)
 792                         i2c_pxa_irq_txempty(i2c, isr);
 793                 if (isr & ISR_IRF)
 794                         i2c_pxa_irq_rxfull(i2c, isr);
 795         } else {
 796                 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
 797         }
 798
 799         return IRQ_HANDLED;
 800 }
 801
 802
 803 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 804 {
 805         struct pxa_i2c *i2c = adap->algo_data;
 806         int ret, i;
 807
 808         /* If the I2C controller is disabled we need to reset it (probably due
 809            to a suspend/resume destroying state). We do this here as we can then
 810            avoid worrying about resuming the controller before its users. */
 811         if (!(readl(_ICR(i2c)) & ICR_IUE))
 812                 i2c_pxa_reset(i2c);
 813
 814         for (i = adap->retries; i >= 0; i--) {
 815                 ret = i2c_pxa_do_xfer(i2c, msgs, num);
 816                 if (ret != I2C_RETRY)
 817                         goto out;
 818
 819                 if (i2c_debug)
 820                         dev_dbg(&adap->dev, "Retrying transmission\n");
 821                 udelay(100);
 822         }
 823         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 824         ret = -EREMOTEIO;
 825  out:
 826         i2c_pxa_set_slave(i2c, ret);
 827         return ret;
 828 }
 829
 830 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
 831 {
 832         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 833 }
 834
 835 static const struct i2c_algorithm i2c_pxa_algorithm = {
 836         .master_xfer    = i2c_pxa_xfer,
 837         .functionality  = i2c_pxa_functionality,
 838 };
 839
 840 static struct pxa_i2c i2c_pxa = {
 841         .lock   = __SPIN_LOCK_UNLOCKED(i2c_pxa.lock),
 842         .adap   = {
 843                 .owner          = THIS_MODULE,
 844                 .algo           = &i2c_pxa_algorithm,
 845                 .name           = "pxa2xx-i2c.0",
 846                 .retries        = 5,
 847         },
 848 };
 849
 850 #define res_len(r)              ((r)->end - (r)->start + 1)
 851 static int i2c_pxa_probe(struct platform_device *dev)
 852 {
 853         struct pxa_i2c *i2c = &i2c_pxa;
 854         struct resource *res;
 855         struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
 856         int ret;
 857         int irq;
 858
 859         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 860         irq = platform_get_irq(dev, 0);
 861         if (res == NULL || irq < 0)
 862                 return -ENODEV;
 863
 864         if (!request_mem_region(res->start, res_len(res), res->name))
 865                 return -ENOMEM;
 866
 867         i2c = kmalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
 868         if (!i2c) {
 869                 ret = -ENOMEM;
 870                 goto emalloc;
 871         }
 872
 873         memcpy(i2c, &i2c_pxa, sizeof(struct pxa_i2c));
 874         init_waitqueue_head(&i2c->wait);
 875         i2c->adap.name[strlen(i2c->adap.name) - 1] = '0' + dev->id % 10;
 876
 877         i2c->reg_base = ioremap(res->start, res_len(res));
 878         if (!i2c->reg_base) {
 879                 ret = -EIO;
 880                 goto eremap;
 881         }
 882
 883         i2c->iobase = res->start;
 884         i2c->iosize = res_len(res);
 885
 886         i2c->irq = irq;
 887
 888         i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
 889
 890 #ifdef CONFIG_I2C_PXA_SLAVE
 891         if (plat) {
 892                 i2c->slave_addr = plat->slave_addr;
 893                 i2c->slave = plat->slave;
 894         }
 895 #endif
 896
 897         switch (dev->id) {
 898         case 0:
 899 #ifdef CONFIG_PXA27x
 900                 pxa_gpio_mode(GPIO117_I2CSCL_MD);
 901                 pxa_gpio_mode(GPIO118_I2CSDA_MD);
 902 #endif
 903                 pxa_set_cken(CKEN_I2C, 1);
 904                 break;
 905 #ifdef CONFIG_PXA27x
 906         case 1:
 907                 local_irq_disable();
 908                 PCFR |= PCFR_PI2CEN;
 909                 local_irq_enable();
 910                 pxa_set_cken(CKEN_PWRI2C, 1);
 911 #endif
 912         }
 913
 914         ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
 915                           i2c->adap.name, i2c);
 916         if (ret)
 917                 goto ereqirq;
 918
 919
 920         i2c_pxa_reset(i2c);
 921
 922         i2c->adap.algo_data = i2c;
 923         i2c->adap.dev.parent = &dev->dev;
 924
 925         if (plat) {
 926                 i2c->adap.class = plat->class;
 927         }
 928
 929         ret = i2c_add_adapter(&i2c->adap);
 930         if (ret < 0) {
 931                 printk(KERN_INFO "I2C: Failed to add bus\n");
 932                 goto eadapt;
 933         }
 934
 935         platform_set_drvdata(dev, i2c);
 936
 937 #ifdef CONFIG_I2C_PXA_SLAVE
 938         printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
 939                i2c->adap.dev.bus_id, i2c->slave_addr);
 940 #else
 941         printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
 942                i2c->adap.dev.bus_id);
 943 #endif
 944         return 0;
 945
 946 eadapt:
 947         free_irq(irq, i2c);
 948 ereqirq:
 949         switch (dev->id) {
 950         case 0:
 951                 pxa_set_cken(CKEN_I2C, 0);
 952                 break;
 953 #ifdef CONFIG_PXA27x
 954         case 1:
 955                 pxa_set_cken(CKEN_PWRI2C, 0);
 956                 local_irq_disable();
 957                 PCFR &= ~PCFR_PI2CEN;
 958                 local_irq_enable();
 959 #endif
 960         }
 961 eremap:
 962         kfree(i2c);
 963 emalloc:
 964         release_mem_region(res->start, res_len(res));
 965         return ret;
 966 }
 967
 968 static int i2c_pxa_remove(struct platform_device *dev)
 969 {
 970         struct pxa_i2c *i2c = platform_get_drvdata(dev);
 971
 972         platform_set_drvdata(dev, NULL);
 973
 974         i2c_del_adapter(&i2c->adap);
 975         free_irq(i2c->irq, i2c);
 976         switch (dev->id) {
 977         case 0:
 978                 pxa_set_cken(CKEN_I2C, 0);
 979                 break;
 980 #ifdef CONFIG_PXA27x
 981         case 1:
 982                 pxa_set_cken(CKEN_PWRI2C, 0);
 983                 local_irq_disable();
 984                 PCFR &= ~PCFR_PI2CEN;
 985                 local_irq_enable();
 986 #endif
 987         }
 988         release_mem_region(i2c->iobase, i2c->iosize);
 989         kfree(i2c);
 990
 991         return 0;
 992 }
 993
 994 static struct platform_driver i2c_pxa_driver = {
 995         .probe          = i2c_pxa_probe,
 996         .remove         = i2c_pxa_remove,
 997         .driver         = {
 998                 .name   = "pxa2xx-i2c",
 999         },
1000 };
1001
1002 static int __init i2c_adap_pxa_init(void)
1003 {
1004         return platform_driver_register(&i2c_pxa_driver);
1005 }
1006
1007 static void i2c_adap_pxa_exit(void)
1008 {
1009         return platform_driver_unregister(&i2c_pxa_driver);
1010 }
1011
1012 MODULE_LICENSE("GPL");
1013
1014 module_init(i2c_adap_pxa_init);
1015 module_exit(i2c_adap_pxa_exit);