git.oblomov.eu Git - linux-2.6/blob - 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 #include <linux/err.h>
  35 #include <linux/clk.h>
  36
  37 #include <mach/hardware.h>
  38 #include <asm/irq.h>
  39 #include <asm/io.h>
  40 #include <mach/i2c.h>
  41
  42 /*
  43  * I2C registers and bit definitions
  44  */
  45 #define IBMR            (0x00)
  46 #define IDBR            (0x08)
  47 #define ICR             (0x10)
  48 #define ISR             (0x18)
  49 #define ISAR            (0x20)
  50
  51 #define ICR_START       (1 << 0)           /* start bit */
  52 #define ICR_STOP        (1 << 1)           /* stop bit */
  53 #define ICR_ACKNAK      (1 << 2)           /* send ACK(0) or NAK(1) */
  54 #define ICR_TB          (1 << 3)           /* transfer byte bit */
  55 #define ICR_MA          (1 << 4)           /* master abort */
  56 #define ICR_SCLE        (1 << 5)           /* master clock enable */
  57 #define ICR_IUE         (1 << 6)           /* unit enable */
  58 #define ICR_GCD         (1 << 7)           /* general call disable */
  59 #define ICR_ITEIE       (1 << 8)           /* enable tx interrupts */
  60 #define ICR_IRFIE       (1 << 9)           /* enable rx interrupts */
  61 #define ICR_BEIE        (1 << 10)          /* enable bus error ints */
  62 #define ICR_SSDIE       (1 << 11)          /* slave STOP detected int enable */
  63 #define ICR_ALDIE       (1 << 12)          /* enable arbitration interrupt */
  64 #define ICR_SADIE       (1 << 13)          /* slave address detected int enable */
  65 #define ICR_UR          (1 << 14)          /* unit reset */
  66 #define ICR_FM          (1 << 15)          /* fast mode */
  67
  68 #define ISR_RWM         (1 << 0)           /* read/write mode */
  69 #define ISR_ACKNAK      (1 << 1)           /* ack/nak status */
  70 #define ISR_UB          (1 << 2)           /* unit busy */
  71 #define ISR_IBB         (1 << 3)           /* bus busy */
  72 #define ISR_SSD         (1 << 4)           /* slave stop detected */
  73 #define ISR_ALD         (1 << 5)           /* arbitration loss detected */
  74 #define ISR_ITE         (1 << 6)           /* tx buffer empty */
  75 #define ISR_IRF         (1 << 7)           /* rx buffer full */
  76 #define ISR_GCAD        (1 << 8)           /* general call address detected */
  77 #define ISR_SAD         (1 << 9)           /* slave address detected */
  78 #define ISR_BED         (1 << 10)          /* bus error no ACK/NAK */
  79
  80 struct pxa_i2c {
  81         spinlock_t              lock;
  82         wait_queue_head_t       wait;
  83         struct i2c_msg          *msg;
  84         unsigned int            msg_num;
  85         unsigned int            msg_idx;
  86         unsigned int            msg_ptr;
  87         unsigned int            slave_addr;
  88
  89         struct i2c_adapter      adap;
  90         struct clk              *clk;
  91 #ifdef CONFIG_I2C_PXA_SLAVE
  92         struct i2c_slave_client *slave;
  93 #endif
  94
  95         unsigned int            irqlogidx;
  96         u32                     isrlog[32];
  97         u32                     icrlog[32];
  98
  99         void __iomem            *reg_base;
 100         unsigned int            reg_shift;
 101
 102         unsigned long           iobase;
 103         unsigned long           iosize;
 104
 105         int                     irq;
 106         unsigned int            use_pio :1;
 107         unsigned int            fast_mode :1;
 108 };
 109
 110 #define _IBMR(i2c)      ((i2c)->reg_base + (0x0 << (i2c)->reg_shift))
 111 #define _IDBR(i2c)      ((i2c)->reg_base + (0x4 << (i2c)->reg_shift))
 112 #define _ICR(i2c)       ((i2c)->reg_base + (0x8 << (i2c)->reg_shift))
 113 #define _ISR(i2c)       ((i2c)->reg_base + (0xc << (i2c)->reg_shift))
 114 #define _ISAR(i2c)      ((i2c)->reg_base + (0x10 << (i2c)->reg_shift))
 115
 116 /*
 117  * I2C Slave mode address
 118  */
 119 #define I2C_PXA_SLAVE_ADDR      0x1
 120
 121 #ifdef DEBUG
 122
 123 struct bits {
 124         u32     mask;
 125         const char *set;
 126         const char *unset;
 127 };
 128 #define PXA_BIT(m, s, u)        { .mask = m, .set = s, .unset = u }
 129
 130 static inline void
 131 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
 132 {
 133         printk("%s %08x: ", prefix, val);
 134         while (num--) {
 135                 const char *str = val & bits->mask ? bits->set : bits->unset;
 136                 if (str)
 137                         printk("%s ", str);
 138                 bits++;
 139         }
 140 }
 141
 142 static const struct bits isr_bits[] = {
 143         PXA_BIT(ISR_RWM,        "RX",           "TX"),
 144         PXA_BIT(ISR_ACKNAK,     "NAK",          "ACK"),
 145         PXA_BIT(ISR_UB,         "Bsy",          "Rdy"),
 146         PXA_BIT(ISR_IBB,        "BusBsy",       "BusRdy"),
 147         PXA_BIT(ISR_SSD,        "SlaveStop",    NULL),
 148         PXA_BIT(ISR_ALD,        "ALD",          NULL),
 149         PXA_BIT(ISR_ITE,        "TxEmpty",      NULL),
 150         PXA_BIT(ISR_IRF,        "RxFull",       NULL),
 151         PXA_BIT(ISR_GCAD,       "GenCall",      NULL),
 152         PXA_BIT(ISR_SAD,        "SlaveAddr",    NULL),
 153         PXA_BIT(ISR_BED,        "BusErr",       NULL),
 154 };
 155
 156 static void decode_ISR(unsigned int val)
 157 {
 158         decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
 159         printk("\n");
 160 }
 161
 162 static const struct bits icr_bits[] = {
 163         PXA_BIT(ICR_START,  "START",    NULL),
 164         PXA_BIT(ICR_STOP,   "STOP",     NULL),
 165         PXA_BIT(ICR_ACKNAK, "ACKNAK",   NULL),
 166         PXA_BIT(ICR_TB,     "TB",       NULL),
 167         PXA_BIT(ICR_MA,     "MA",       NULL),
 168         PXA_BIT(ICR_SCLE,   "SCLE",     "scle"),
 169         PXA_BIT(ICR_IUE,    "IUE",      "iue"),
 170         PXA_BIT(ICR_GCD,    "GCD",      NULL),
 171         PXA_BIT(ICR_ITEIE,  "ITEIE",    NULL),
 172         PXA_BIT(ICR_IRFIE,  "IRFIE",    NULL),
 173         PXA_BIT(ICR_BEIE,   "BEIE",     NULL),
 174         PXA_BIT(ICR_SSDIE,  "SSDIE",    NULL),
 175         PXA_BIT(ICR_ALDIE,  "ALDIE",    NULL),
 176         PXA_BIT(ICR_SADIE,  "SADIE",    NULL),
 177         PXA_BIT(ICR_UR,     "UR",               "ur"),
 178 };
 179
 180 #ifdef CONFIG_I2C_PXA_SLAVE
 181 static void decode_ICR(unsigned int val)
 182 {
 183         decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
 184         printk("\n");
 185 }
 186 #endif
 187
 188 static unsigned int i2c_debug = DEBUG;
 189
 190 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
 191 {
 192         dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
 193                 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 194 }
 195
 196 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
 197 #else
 198 #define i2c_debug       0
 199
 200 #define show_state(i2c) do { } while (0)
 201 #define decode_ISR(val) do { } while (0)
 202 #define decode_ICR(val) do { } while (0)
 203 #endif
 204
 205 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
 206
 207 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
 208 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
 209
 210 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
 211 {
 212         unsigned int i;
 213         printk(KERN_ERR "i2c: error: %s\n", why);
 214         printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
 215                 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
 216         printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
 217                readl(_ICR(i2c)), readl(_ISR(i2c)));
 218         printk(KERN_DEBUG "i2c: log: ");
 219         for (i = 0; i < i2c->irqlogidx; i++)
 220                 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
 221         printk("\n");
 222 }
 223
 224 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
 225 {
 226         return !(readl(_ICR(i2c)) & ICR_SCLE);
 227 }
 228
 229 static void i2c_pxa_abort(struct pxa_i2c *i2c)
 230 {
 231         int i = 250;
 232
 233         if (i2c_pxa_is_slavemode(i2c)) {
 234                 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
 235                 return;
 236         }
 237
 238         while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
 239                 unsigned long icr = readl(_ICR(i2c));
 240
 241                 icr &= ~ICR_START;
 242                 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
 243
 244                 writel(icr, _ICR(i2c));
 245
 246                 show_state(i2c);
 247
 248                 mdelay(1);
 249                 i --;
 250         }
 251
 252         writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
 253                _ICR(i2c));
 254 }
 255
 256 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
 257 {
 258         int timeout = DEF_TIMEOUT;
 259
 260         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
 261                 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
 262                         timeout += 4;
 263
 264                 msleep(2);
 265                 show_state(i2c);
 266         }
 267
 268         if (timeout < 0)
 269                 show_state(i2c);
 270
 271         return timeout < 0 ? I2C_RETRY : 0;
 272 }
 273
 274 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
 275 {
 276         unsigned long timeout = jiffies + HZ*4;
 277
 278         while (time_before(jiffies, timeout)) {
 279                 if (i2c_debug > 1)
 280                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 281                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 282
 283                 if (readl(_ISR(i2c)) & ISR_SAD) {
 284                         if (i2c_debug > 0)
 285                                 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
 286                         goto out;
 287                 }
 288
 289                 /* wait for unit and bus being not busy, and we also do a
 290                  * quick check of the i2c lines themselves to ensure they've
 291                  * gone high...
 292                  */
 293                 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
 294                         if (i2c_debug > 0)
 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  out:
 305         return 0;
 306 }
 307
 308 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
 309 {
 310         if (i2c_debug)
 311                 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
 312
 313         if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
 314                 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
 315                 if (!i2c_pxa_wait_master(i2c)) {
 316                         dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
 317                         return I2C_RETRY;
 318                 }
 319         }
 320
 321         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
 322         return 0;
 323 }
 324
 325 #ifdef CONFIG_I2C_PXA_SLAVE
 326 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
 327 {
 328         unsigned long timeout = jiffies + HZ*1;
 329
 330         /* wait for stop */
 331
 332         show_state(i2c);
 333
 334         while (time_before(jiffies, timeout)) {
 335                 if (i2c_debug > 1)
 336                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 337                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 338
 339                 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
 340                     (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
 341                     (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
 342                         if (i2c_debug > 1)
 343                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
 344                         return 1;
 345                 }
 346
 347                 msleep(1);
 348         }
 349
 350         if (i2c_debug > 0)
 351                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
 352         return 0;
 353 }
 354
 355 /*
 356  * clear the hold on the bus, and take of anything else
 357  * that has been configured
 358  */
 359 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
 360 {
 361         show_state(i2c);
 362
 363         if (errcode < 0) {
 364                 udelay(100);   /* simple delay */
 365         } else {
 366                 /* we need to wait for the stop condition to end */
 367
 368                 /* if we where in stop, then clear... */
 369                 if (readl(_ICR(i2c)) & ICR_STOP) {
 370                         udelay(100);
 371                         writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
 372                 }
 373
 374                 if (!i2c_pxa_wait_slave(i2c)) {
 375                         dev_err(&i2c->adap.dev, "%s: wait timedout\n",
 376                                 __func__);
 377                         return;
 378                 }
 379         }
 380
 381         writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
 382         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 383
 384         if (i2c_debug) {
 385                 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
 386                 decode_ICR(readl(_ICR(i2c)));
 387         }
 388 }
 389 #else
 390 #define i2c_pxa_set_slave(i2c, err)     do { } while (0)
 391 #endif
 392
 393 static void i2c_pxa_reset(struct pxa_i2c *i2c)
 394 {
 395         pr_debug("Resetting I2C Controller Unit\n");
 396
 397         /* abort any transfer currently under way */
 398         i2c_pxa_abort(i2c);
 399
 400         /* reset according to 9.8 */
 401         writel(ICR_UR, _ICR(i2c));
 402         writel(I2C_ISR_INIT, _ISR(i2c));
 403         writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
 404
 405         writel(i2c->slave_addr, _ISAR(i2c));
 406
 407         /* set control register values */
 408         writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
 409
 410 #ifdef CONFIG_I2C_PXA_SLAVE
 411         dev_info(&i2c->adap.dev, "Enabling slave mode\n");
 412         writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
 413 #endif
 414
 415         i2c_pxa_set_slave(i2c, 0);
 416
 417         /* enable unit */
 418         writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
 419         udelay(100);
 420 }
 421
 422
 423 #ifdef CONFIG_I2C_PXA_SLAVE
 424 /*
 425  * PXA I2C Slave mode
 426  */
 427
 428 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
 429 {
 430         if (isr & ISR_BED) {
 431                 /* what should we do here? */
 432         } else {
 433                 int ret = 0;
 434
 435                 if (i2c->slave != NULL)
 436                         ret = i2c->slave->read(i2c->slave->data);
 437
 438                 writel(ret, _IDBR(i2c));
 439                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));   /* allow next byte */
 440         }
 441 }
 442
 443 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
 444 {
 445         unsigned int byte = readl(_IDBR(i2c));
 446
 447         if (i2c->slave != NULL)
 448                 i2c->slave->write(i2c->slave->data, byte);
 449
 450         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 451 }
 452
 453 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
 454 {
 455         int timeout;
 456
 457         if (i2c_debug > 0)
 458                 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
 459                        (isr & ISR_RWM) ? 'r' : 't');
 460
 461         if (i2c->slave != NULL)
 462                 i2c->slave->event(i2c->slave->data,
 463                                  (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
 464
 465         /*
 466          * slave could interrupt in the middle of us generating a
 467          * start condition... if this happens, we'd better back off
 468          * and stop holding the poor thing up
 469          */
 470         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
 471         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 472
 473         timeout = 0x10000;
 474
 475         while (1) {
 476                 if ((readl(_IBMR(i2c)) & 2) == 2)
 477                         break;
 478
 479                 timeout--;
 480
 481                 if (timeout <= 0) {
 482                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
 483                         break;
 484                 }
 485         }
 486
 487         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 488 }
 489
 490 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
 491 {
 492         if (i2c_debug > 2)
 493                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
 494
 495         if (i2c->slave != NULL)
 496                 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
 497
 498         if (i2c_debug > 2)
 499                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
 500
 501         /*
 502          * If we have a master-mode message waiting,
 503          * kick it off now that the slave has completed.
 504          */
 505         if (i2c->msg)
 506                 i2c_pxa_master_complete(i2c, I2C_RETRY);
 507 }
 508 #else
 509 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
 510 {
 511         if (isr & ISR_BED) {
 512                 /* what should we do here? */
 513         } else {
 514                 writel(0, _IDBR(i2c));
 515                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 516         }
 517 }
 518
 519 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
 520 {
 521         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
 522 }
 523
 524 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
 525 {
 526         int timeout;
 527
 528         /*
 529          * slave could interrupt in the middle of us generating a
 530          * start condition... if this happens, we'd better back off
 531          * and stop holding the poor thing up
 532          */
 533         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
 534         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
 535
 536         timeout = 0x10000;
 537
 538         while (1) {
 539                 if ((readl(_IBMR(i2c)) & 2) == 2)
 540                         break;
 541
 542                 timeout--;
 543
 544                 if (timeout <= 0) {
 545                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
 546                         break;
 547                 }
 548         }
 549
 550         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 551 }
 552
 553 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
 554 {
 555         if (i2c->msg)
 556                 i2c_pxa_master_complete(i2c, I2C_RETRY);
 557 }
 558 #endif
 559
 560 /*
 561  * PXA I2C Master mode
 562  */
 563
 564 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
 565 {
 566         unsigned int addr = (msg->addr & 0x7f) << 1;
 567
 568         if (msg->flags & I2C_M_RD)
 569                 addr |= 1;
 570
 571         return addr;
 572 }
 573
 574 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
 575 {
 576         u32 icr;
 577
 578         /*
 579          * Step 1: target slave address into IDBR
 580          */
 581         writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
 582
 583         /*
 584          * Step 2: initiate the write.
 585          */
 586         icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
 587         writel(icr | ICR_START | ICR_TB, _ICR(i2c));
 588 }
 589
 590 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
 591 {
 592         u32 icr;
 593
 594         /*
 595          * Clear the STOP and ACK flags
 596          */
 597         icr = readl(_ICR(i2c));
 598         icr &= ~(ICR_STOP | ICR_ACKNAK);
 599         writel(icr, _ICR(i2c));
 600 }
 601
 602 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
 603 {
 604         /* make timeout the same as for interrupt based functions */
 605         long timeout = 2 * DEF_TIMEOUT;
 606
 607         /*
 608          * Wait for the bus to become free.
 609          */
 610         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
 611                 udelay(1000);
 612                 show_state(i2c);
 613         }
 614
 615         if (timeout < 0) {
 616                 show_state(i2c);
 617                 dev_err(&i2c->adap.dev,
 618                         "i2c_pxa: timeout waiting for bus free\n");
 619                 return I2C_RETRY;
 620         }
 621
 622         /*
 623          * Set master mode.
 624          */
 625         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
 626
 627         return 0;
 628 }
 629
 630 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
 631                                struct i2c_msg *msg, int num)
 632 {
 633         unsigned long timeout = 500000; /* 5 seconds */
 634         int ret = 0;
 635
 636         ret = i2c_pxa_pio_set_master(i2c);
 637         if (ret)
 638                 goto out;
 639
 640         i2c->msg = msg;
 641         i2c->msg_num = num;
 642         i2c->msg_idx = 0;
 643         i2c->msg_ptr = 0;
 644         i2c->irqlogidx = 0;
 645
 646         i2c_pxa_start_message(i2c);
 647
 648         while (i2c->msg_num > 0 && --timeout) {
 649                 i2c_pxa_handler(0, i2c);
 650                 udelay(10);
 651         }
 652
 653         i2c_pxa_stop_message(i2c);
 654
 655         /*
 656          * We place the return code in i2c->msg_idx.
 657          */
 658         ret = i2c->msg_idx;
 659
 660 out:
 661         if (timeout == 0)
 662                 i2c_pxa_scream_blue_murder(i2c, "timeout");
 663
 664         return ret;
 665 }
 666
 667 /*
 668  * We are protected by the adapter bus mutex.
 669  */
 670 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 671 {
 672         long timeout;
 673         int ret;
 674
 675         /*
 676          * Wait for the bus to become free.
 677          */
 678         ret = i2c_pxa_wait_bus_not_busy(i2c);
 679         if (ret) {
 680                 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
 681                 goto out;
 682         }
 683
 684         /*
 685          * Set master mode.
 686          */
 687         ret = i2c_pxa_set_master(i2c);
 688         if (ret) {
 689                 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
 690                 goto out;
 691         }
 692
 693         spin_lock_irq(&i2c->lock);
 694
 695         i2c->msg = msg;
 696         i2c->msg_num = num;
 697         i2c->msg_idx = 0;
 698         i2c->msg_ptr = 0;
 699         i2c->irqlogidx = 0;
 700
 701         i2c_pxa_start_message(i2c);
 702
 703         spin_unlock_irq(&i2c->lock);
 704
 705         /*
 706          * The rest of the processing occurs in the interrupt handler.
 707          */
 708         timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
 709         i2c_pxa_stop_message(i2c);
 710
 711         /*
 712          * We place the return code in i2c->msg_idx.
 713          */
 714         ret = i2c->msg_idx;
 715
 716         if (timeout == 0)
 717                 i2c_pxa_scream_blue_murder(i2c, "timeout");
 718
 719  out:
 720         return ret;
 721 }
 722
 723 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
 724                             struct i2c_msg msgs[], int num)
 725 {
 726         struct pxa_i2c *i2c = adap->algo_data;
 727         int ret, i;
 728
 729         /* If the I2C controller is disabled we need to reset it
 730           (probably due to a suspend/resume destroying state). We do
 731           this here as we can then avoid worrying about resuming the
 732           controller before its users. */
 733         if (!(readl(_ICR(i2c)) & ICR_IUE))
 734                 i2c_pxa_reset(i2c);
 735
 736         for (i = adap->retries; i >= 0; i--) {
 737                 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
 738                 if (ret != I2C_RETRY)
 739                         goto out;
 740
 741                 if (i2c_debug)
 742                         dev_dbg(&adap->dev, "Retrying transmission\n");
 743                 udelay(100);
 744         }
 745         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 746         ret = -EREMOTEIO;
 747  out:
 748         i2c_pxa_set_slave(i2c, ret);
 749         return ret;
 750 }
 751
 752 /*
 753  * i2c_pxa_master_complete - complete the message and wake up.
 754  */
 755 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
 756 {
 757         i2c->msg_ptr = 0;
 758         i2c->msg = NULL;
 759         i2c->msg_idx ++;
 760         i2c->msg_num = 0;
 761         if (ret)
 762                 i2c->msg_idx = ret;
 763         if (!i2c->use_pio)
 764                 wake_up(&i2c->wait);
 765 }
 766
 767 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
 768 {
 769         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
 770
 771  again:
 772         /*
 773          * If ISR_ALD is set, we lost arbitration.
 774          */
 775         if (isr & ISR_ALD) {
 776                 /*
 777                  * Do we need to do anything here?  The PXA docs
 778                  * are vague about what happens.
 779                  */
 780                 i2c_pxa_scream_blue_murder(i2c, "ALD set");
 781
 782                 /*
 783                  * We ignore this error.  We seem to see spurious ALDs
 784                  * for seemingly no reason.  If we handle them as I think
 785                  * they should, we end up causing an I2C error, which
 786                  * is painful for some systems.
 787                  */
 788                 return; /* ignore */
 789         }
 790
 791         if (isr & ISR_BED) {
 792                 int ret = BUS_ERROR;
 793
 794                 /*
 795                  * I2C bus error - either the device NAK'd us, or
 796                  * something more serious happened.  If we were NAK'd
 797                  * on the initial address phase, we can retry.
 798                  */
 799                 if (isr & ISR_ACKNAK) {
 800                         if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
 801                                 ret = I2C_RETRY;
 802                         else
 803                                 ret = XFER_NAKED;
 804                 }
 805                 i2c_pxa_master_complete(i2c, ret);
 806         } else if (isr & ISR_RWM) {
 807                 /*
 808                  * Read mode.  We have just sent the address byte, and
 809                  * now we must initiate the transfer.
 810                  */
 811                 if (i2c->msg_ptr == i2c->msg->len - 1 &&
 812                     i2c->msg_idx == i2c->msg_num - 1)
 813                         icr |= ICR_STOP | ICR_ACKNAK;
 814
 815                 icr |= ICR_ALDIE | ICR_TB;
 816         } else if (i2c->msg_ptr < i2c->msg->len) {
 817                 /*
 818                  * Write mode.  Write the next data byte.
 819                  */
 820                 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
 821
 822                 icr |= ICR_ALDIE | ICR_TB;
 823
 824                 /*
 825                  * If this is the last byte of the last message, send
 826                  * a STOP.
 827                  */
 828                 if (i2c->msg_ptr == i2c->msg->len &&
 829                     i2c->msg_idx == i2c->msg_num - 1)
 830                         icr |= ICR_STOP;
 831         } else if (i2c->msg_idx < i2c->msg_num - 1) {
 832                 /*
 833                  * Next segment of the message.
 834                  */
 835                 i2c->msg_ptr = 0;
 836                 i2c->msg_idx ++;
 837                 i2c->msg++;
 838
 839                 /*
 840                  * If we aren't doing a repeated start and address,
 841                  * go back and try to send the next byte.  Note that
 842                  * we do not support switching the R/W direction here.
 843                  */
 844                 if (i2c->msg->flags & I2C_M_NOSTART)
 845                         goto again;
 846
 847                 /*
 848                  * Write the next address.
 849                  */
 850                 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
 851
 852                 /*
 853                  * And trigger a repeated start, and send the byte.
 854                  */
 855                 icr &= ~ICR_ALDIE;
 856                 icr |= ICR_START | ICR_TB;
 857         } else {
 858                 if (i2c->msg->len == 0) {
 859                         /*
 860                          * Device probes have a message length of zero
 861                          * and need the bus to be reset before it can
 862                          * be used again.
 863                          */
 864                         i2c_pxa_reset(i2c);
 865                 }
 866                 i2c_pxa_master_complete(i2c, 0);
 867         }
 868
 869         i2c->icrlog[i2c->irqlogidx-1] = icr;
 870
 871         writel(icr, _ICR(i2c));
 872         show_state(i2c);
 873 }
 874
 875 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
 876 {
 877         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
 878
 879         /*
 880          * Read the byte.
 881          */
 882         i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
 883
 884         if (i2c->msg_ptr < i2c->msg->len) {
 885                 /*
 886                  * If this is the last byte of the last
 887                  * message, send a STOP.
 888                  */
 889                 if (i2c->msg_ptr == i2c->msg->len - 1)
 890                         icr |= ICR_STOP | ICR_ACKNAK;
 891
 892                 icr |= ICR_ALDIE | ICR_TB;
 893         } else {
 894                 i2c_pxa_master_complete(i2c, 0);
 895         }
 896
 897         i2c->icrlog[i2c->irqlogidx-1] = icr;
 898
 899         writel(icr, _ICR(i2c));
 900 }
 901
 902 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
 903 {
 904         struct pxa_i2c *i2c = dev_id;
 905         u32 isr = readl(_ISR(i2c));
 906
 907         if (i2c_debug > 2 && 0) {
 908                 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 909                         __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
 910                 decode_ISR(isr);
 911         }
 912
 913         if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
 914                 i2c->isrlog[i2c->irqlogidx++] = isr;
 915
 916         show_state(i2c);
 917
 918         /*
 919          * Always clear all pending IRQs.
 920          */
 921         writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
 922
 923         if (isr & ISR_SAD)
 924                 i2c_pxa_slave_start(i2c, isr);
 925         if (isr & ISR_SSD)
 926                 i2c_pxa_slave_stop(i2c);
 927
 928         if (i2c_pxa_is_slavemode(i2c)) {
 929                 if (isr & ISR_ITE)
 930                         i2c_pxa_slave_txempty(i2c, isr);
 931                 if (isr & ISR_IRF)
 932                         i2c_pxa_slave_rxfull(i2c, isr);
 933         } else if (i2c->msg) {
 934                 if (isr & ISR_ITE)
 935                         i2c_pxa_irq_txempty(i2c, isr);
 936                 if (isr & ISR_IRF)
 937                         i2c_pxa_irq_rxfull(i2c, isr);
 938         } else {
 939                 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
 940         }
 941
 942         return IRQ_HANDLED;
 943 }
 944
 945
 946 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 947 {
 948         struct pxa_i2c *i2c = adap->algo_data;
 949         int ret, i;
 950
 951         for (i = adap->retries; i >= 0; i--) {
 952                 ret = i2c_pxa_do_xfer(i2c, msgs, num);
 953                 if (ret != I2C_RETRY)
 954                         goto out;
 955
 956                 if (i2c_debug)
 957                         dev_dbg(&adap->dev, "Retrying transmission\n");
 958                 udelay(100);
 959         }
 960         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 961         ret = -EREMOTEIO;
 962  out:
 963         i2c_pxa_set_slave(i2c, ret);
 964         return ret;
 965 }
 966
 967 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
 968 {
 969         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 970 }
 971
 972 static const struct i2c_algorithm i2c_pxa_algorithm = {
 973         .master_xfer    = i2c_pxa_xfer,
 974         .functionality  = i2c_pxa_functionality,
 975 };
 976
 977 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
 978         .master_xfer    = i2c_pxa_pio_xfer,
 979         .functionality  = i2c_pxa_functionality,
 980 };
 981
 982 #define res_len(r)              ((r)->end - (r)->start + 1)
 983 static int i2c_pxa_probe(struct platform_device *dev)
 984 {
 985         struct pxa_i2c *i2c;
 986         struct resource *res;
 987         struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
 988         int ret;
 989         int irq;
 990
 991         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 992         irq = platform_get_irq(dev, 0);
 993         if (res == NULL || irq < 0)
 994                 return -ENODEV;
 995
 996         if (!request_mem_region(res->start, res_len(res), res->name))
 997                 return -ENOMEM;
 998
 999         i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1000         if (!i2c) {
1001                 ret = -ENOMEM;
1002                 goto emalloc;
1003         }
1004
1005         i2c->adap.owner   = THIS_MODULE;
1006         i2c->adap.retries = 5;
1007
1008         spin_lock_init(&i2c->lock);
1009         init_waitqueue_head(&i2c->wait);
1010
1011         /*
1012          * If "dev->id" is negative we consider it as zero.
1013          * The reason to do so is to avoid sysfs names that only make
1014          * sense when there are multiple adapters.
1015          */
1016         i2c->adap.nr = dev->id != -1 ? dev->id : 0;
1017         snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
1018                  i2c->adap.nr);
1019
1020         i2c->clk = clk_get(&dev->dev, NULL);
1021         if (IS_ERR(i2c->clk)) {
1022                 ret = PTR_ERR(i2c->clk);
1023                 goto eclk;
1024         }
1025
1026         i2c->reg_base = ioremap(res->start, res_len(res));
1027         if (!i2c->reg_base) {
1028                 ret = -EIO;
1029                 goto eremap;
1030         }
1031         i2c->reg_shift = (cpu_is_pxa3xx() && (dev->id == 1)) ? 0 : 1;
1032
1033         i2c->iobase = res->start;
1034         i2c->iosize = res_len(res);
1035
1036         i2c->irq = irq;
1037
1038         i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1039
1040 #ifdef CONFIG_I2C_PXA_SLAVE
1041         if (plat) {
1042                 i2c->slave_addr = plat->slave_addr;
1043                 i2c->slave = plat->slave;
1044         }
1045 #endif
1046
1047         clk_enable(i2c->clk);
1048
1049         if (plat) {
1050                 i2c->adap.class = plat->class;
1051                 i2c->use_pio = plat->use_pio;
1052                 i2c->fast_mode = plat->fast_mode;
1053         }
1054
1055         if (i2c->use_pio) {
1056                 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1057         } else {
1058                 i2c->adap.algo = &i2c_pxa_algorithm;
1059                 ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
1060                                   i2c->adap.name, i2c);
1061                 if (ret)
1062                         goto ereqirq;
1063         }
1064
1065         i2c_pxa_reset(i2c);
1066
1067         i2c->adap.algo_data = i2c;
1068         i2c->adap.dev.parent = &dev->dev;
1069
1070         ret = i2c_add_numbered_adapter(&i2c->adap);
1071         if (ret < 0) {
1072                 printk(KERN_INFO "I2C: Failed to add bus\n");
1073                 goto eadapt;
1074         }
1075
1076         platform_set_drvdata(dev, i2c);
1077
1078 #ifdef CONFIG_I2C_PXA_SLAVE
1079         printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1080                dev_name(&i2c->adap.dev), i2c->slave_addr);
1081 #else
1082         printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1083                dev_name(&i2c->adap.dev));
1084 #endif
1085         return 0;
1086
1087 eadapt:
1088         if (!i2c->use_pio)
1089                 free_irq(irq, i2c);
1090 ereqirq:
1091         clk_disable(i2c->clk);
1092         iounmap(i2c->reg_base);
1093 eremap:
1094         clk_put(i2c->clk);
1095 eclk:
1096         kfree(i2c);
1097 emalloc:
1098         release_mem_region(res->start, res_len(res));
1099         return ret;
1100 }
1101
1102 static int __exit i2c_pxa_remove(struct platform_device *dev)
1103 {
1104         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1105
1106         platform_set_drvdata(dev, NULL);
1107
1108         i2c_del_adapter(&i2c->adap);
1109         if (!i2c->use_pio)
1110                 free_irq(i2c->irq, i2c);
1111
1112         clk_disable(i2c->clk);
1113         clk_put(i2c->clk);
1114
1115         iounmap(i2c->reg_base);
1116         release_mem_region(i2c->iobase, i2c->iosize);
1117         kfree(i2c);
1118
1119         return 0;
1120 }
1121
1122 #ifdef CONFIG_PM
1123 static int i2c_pxa_suspend_late(struct platform_device *dev, pm_message_t state)
1124 {
1125         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1126         clk_disable(i2c->clk);
1127         return 0;
1128 }
1129
1130 static int i2c_pxa_resume_early(struct platform_device *dev)
1131 {
1132         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1133
1134         clk_enable(i2c->clk);
1135         i2c_pxa_reset(i2c);
1136
1137         return 0;
1138 }
1139 #else
1140 #define i2c_pxa_suspend_late NULL
1141 #define i2c_pxa_resume_early NULL
1142 #endif
1143
1144 static struct platform_driver i2c_pxa_driver = {
1145         .probe          = i2c_pxa_probe,
1146         .remove         = __exit_p(i2c_pxa_remove),
1147         .suspend_late   = i2c_pxa_suspend_late,
1148         .resume_early   = i2c_pxa_resume_early,
1149         .driver         = {
1150                 .name   = "pxa2xx-i2c",
1151                 .owner  = THIS_MODULE,
1152         },
1153 };
1154
1155 static int __init i2c_adap_pxa_init(void)
1156 {
1157         return platform_driver_register(&i2c_pxa_driver);
1158 }
1159
1160 static void __exit i2c_adap_pxa_exit(void)
1161 {
1162         platform_driver_unregister(&i2c_pxa_driver);
1163 }
1164
1165 MODULE_LICENSE("GPL");
1166 MODULE_ALIAS("platform:pxa2xx-i2c");
1167
1168 subsys_initcall(i2c_adap_pxa_init);
1169 module_exit(i2c_adap_pxa_exit);