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 separated 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 <asm/irq.h>
  38 #include <asm/io.h>
  39 #include <plat/i2c.h>
  40
  41 /*
  42  * I2C register offsets will be shifted 0 or 1 bit left, depending on
  43  * different SoCs
  44  */
  45 #define REG_SHIFT_0     (0 << 0)
  46 #define REG_SHIFT_1     (1 << 0)
  47 #define REG_SHIFT(d)    ((d) & 0x1)
  48
  49 static const struct platform_device_id i2c_pxa_id_table[] = {
  50         { "pxa2xx-i2c",         REG_SHIFT_1 },
  51         { "pxa3xx-pwri2c",      REG_SHIFT_0 },
  52         { },
  53 };
  54 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
  55
  56 /*
  57  * I2C registers and bit definitions
  58  */
  59 #define IBMR            (0x00)
  60 #define IDBR            (0x08)
  61 #define ICR             (0x10)
  62 #define ISR             (0x18)
  63 #define ISAR            (0x20)
  64
  65 #define ICR_START       (1 << 0)           /* start bit */
  66 #define ICR_STOP        (1 << 1)           /* stop bit */
  67 #define ICR_ACKNAK      (1 << 2)           /* send ACK(0) or NAK(1) */
  68 #define ICR_TB          (1 << 3)           /* transfer byte bit */
  69 #define ICR_MA          (1 << 4)           /* master abort */
  70 #define ICR_SCLE        (1 << 5)           /* master clock enable */
  71 #define ICR_IUE         (1 << 6)           /* unit enable */
  72 #define ICR_GCD         (1 << 7)           /* general call disable */
  73 #define ICR_ITEIE       (1 << 8)           /* enable tx interrupts */
  74 #define ICR_IRFIE       (1 << 9)           /* enable rx interrupts */
  75 #define ICR_BEIE        (1 << 10)          /* enable bus error ints */
  76 #define ICR_SSDIE       (1 << 11)          /* slave STOP detected int enable */
  77 #define ICR_ALDIE       (1 << 12)          /* enable arbitration interrupt */
  78 #define ICR_SADIE       (1 << 13)          /* slave address detected int enable */
  79 #define ICR_UR          (1 << 14)          /* unit reset */
  80 #define ICR_FM          (1 << 15)          /* fast mode */
  81
  82 #define ISR_RWM         (1 << 0)           /* read/write mode */
  83 #define ISR_ACKNAK      (1 << 1)           /* ack/nak status */
  84 #define ISR_UB          (1 << 2)           /* unit busy */
  85 #define ISR_IBB         (1 << 3)           /* bus busy */
  86 #define ISR_SSD         (1 << 4)           /* slave stop detected */
  87 #define ISR_ALD         (1 << 5)           /* arbitration loss detected */
  88 #define ISR_ITE         (1 << 6)           /* tx buffer empty */
  89 #define ISR_IRF         (1 << 7)           /* rx buffer full */
  90 #define ISR_GCAD        (1 << 8)           /* general call address detected */
  91 #define ISR_SAD         (1 << 9)           /* slave address detected */
  92 #define ISR_BED         (1 << 10)          /* bus error no ACK/NAK */
  93
  94 struct pxa_i2c {
  95         spinlock_t              lock;
  96         wait_queue_head_t       wait;
  97         struct i2c_msg          *msg;
  98         unsigned int            msg_num;
  99         unsigned int            msg_idx;
 100         unsigned int            msg_ptr;
 101         unsigned int            slave_addr;
 102
 103         struct i2c_adapter      adap;
 104         struct clk              *clk;
 105 #ifdef CONFIG_I2C_PXA_SLAVE
 106         struct i2c_slave_client *slave;
 107 #endif
 108
 109         unsigned int            irqlogidx;
 110         u32                     isrlog[32];
 111         u32                     icrlog[32];
 112
 113         void __iomem            *reg_base;
 114         unsigned int            reg_shift;
 115
 116         unsigned long           iobase;
 117         unsigned long           iosize;
 118
 119         int                     irq;
 120         unsigned int            use_pio :1;
 121         unsigned int            fast_mode :1;
 122 };
 123
 124 #define _IBMR(i2c)      ((i2c)->reg_base + (0x0 << (i2c)->reg_shift))
 125 #define _IDBR(i2c)      ((i2c)->reg_base + (0x4 << (i2c)->reg_shift))
 126 #define _ICR(i2c)       ((i2c)->reg_base + (0x8 << (i2c)->reg_shift))
 127 #define _ISR(i2c)       ((i2c)->reg_base + (0xc << (i2c)->reg_shift))
 128 #define _ISAR(i2c)      ((i2c)->reg_base + (0x10 << (i2c)->reg_shift))
 129
 130 /*
 131  * I2C Slave mode address
 132  */
 133 #define I2C_PXA_SLAVE_ADDR      0x1
 134
 135 #ifdef DEBUG
 136
 137 struct bits {
 138         u32     mask;
 139         const char *set;
 140         const char *unset;
 141 };
 142 #define PXA_BIT(m, s, u)        { .mask = m, .set = s, .unset = u }
 143
 144 static inline void
 145 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
 146 {
 147         printk("%s %08x: ", prefix, val);
 148         while (num--) {
 149                 const char *str = val & bits->mask ? bits->set : bits->unset;
 150                 if (str)
 151                         printk("%s ", str);
 152                 bits++;
 153         }
 154 }
 155
 156 static const struct bits isr_bits[] = {
 157         PXA_BIT(ISR_RWM,        "RX",           "TX"),
 158         PXA_BIT(ISR_ACKNAK,     "NAK",          "ACK"),
 159         PXA_BIT(ISR_UB,         "Bsy",          "Rdy"),
 160         PXA_BIT(ISR_IBB,        "BusBsy",       "BusRdy"),
 161         PXA_BIT(ISR_SSD,        "SlaveStop",    NULL),
 162         PXA_BIT(ISR_ALD,        "ALD",          NULL),
 163         PXA_BIT(ISR_ITE,        "TxEmpty",      NULL),
 164         PXA_BIT(ISR_IRF,        "RxFull",       NULL),
 165         PXA_BIT(ISR_GCAD,       "GenCall",      NULL),
 166         PXA_BIT(ISR_SAD,        "SlaveAddr",    NULL),
 167         PXA_BIT(ISR_BED,        "BusErr",       NULL),
 168 };
 169
 170 static void decode_ISR(unsigned int val)
 171 {
 172         decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
 173         printk("\n");
 174 }
 175
 176 static const struct bits icr_bits[] = {
 177         PXA_BIT(ICR_START,  "START",    NULL),
 178         PXA_BIT(ICR_STOP,   "STOP",     NULL),
 179         PXA_BIT(ICR_ACKNAK, "ACKNAK",   NULL),
 180         PXA_BIT(ICR_TB,     "TB",       NULL),
 181         PXA_BIT(ICR_MA,     "MA",       NULL),
 182         PXA_BIT(ICR_SCLE,   "SCLE",     "scle"),
 183         PXA_BIT(ICR_IUE,    "IUE",      "iue"),
 184         PXA_BIT(ICR_GCD,    "GCD",      NULL),
 185         PXA_BIT(ICR_ITEIE,  "ITEIE",    NULL),
 186         PXA_BIT(ICR_IRFIE,  "IRFIE",    NULL),
 187         PXA_BIT(ICR_BEIE,   "BEIE",     NULL),
 188         PXA_BIT(ICR_SSDIE,  "SSDIE",    NULL),
 189         PXA_BIT(ICR_ALDIE,  "ALDIE",    NULL),
 190         PXA_BIT(ICR_SADIE,  "SADIE",    NULL),
 191         PXA_BIT(ICR_UR,     "UR",               "ur"),
 192 };
 193
 194 #ifdef CONFIG_I2C_PXA_SLAVE
 195 static void decode_ICR(unsigned int val)
 196 {
 197         decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
 198         printk("\n");
 199 }
 200 #endif
 201
 202 static unsigned int i2c_debug = DEBUG;
 203
 204 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
 205 {
 206         dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
 207                 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 208 }
 209
 210 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
 211 #else
 212 #define i2c_debug       0
 213
 214 #define show_state(i2c) do { } while (0)
 215 #define decode_ISR(val) do { } while (0)
 216 #define decode_ICR(val) do { } while (0)
 217 #endif
 218
 219 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
 220
 221 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
 222 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
 223
 224 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
 225 {
 226         unsigned int i;
 227         printk(KERN_ERR "i2c: error: %s\n", why);
 228         printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
 229                 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
 230         printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
 231                readl(_ICR(i2c)), readl(_ISR(i2c)));
 232         printk(KERN_DEBUG "i2c: log: ");
 233         for (i = 0; i < i2c->irqlogidx; i++)
 234                 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
 235         printk("\n");
 236 }
 237
 238 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
 239 {
 240         return !(readl(_ICR(i2c)) & ICR_SCLE);
 241 }
 242
 243 static void i2c_pxa_abort(struct pxa_i2c *i2c)
 244 {
 245         int i = 250;
 246
 247         if (i2c_pxa_is_slavemode(i2c)) {
 248                 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
 249                 return;
 250         }
 251
 252         while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
 253                 unsigned long icr = readl(_ICR(i2c));
 254
 255                 icr &= ~ICR_START;
 256                 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
 257
 258                 writel(icr, _ICR(i2c));
 259
 260                 show_state(i2c);
 261
 262                 mdelay(1);
 263                 i --;
 264         }
 265
 266         writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
 267                _ICR(i2c));
 268 }
 269
 270 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
 271 {
 272         int timeout = DEF_TIMEOUT;
 273
 274         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
 275                 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
 276                         timeout += 4;
 277
 278                 msleep(2);
 279                 show_state(i2c);
 280         }
 281
 282         if (timeout < 0)
 283                 show_state(i2c);
 284
 285         return timeout < 0 ? I2C_RETRY : 0;
 286 }
 287
 288 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
 289 {
 290         unsigned long timeout = jiffies + HZ*4;
 291
 292         while (time_before(jiffies, timeout)) {
 293                 if (i2c_debug > 1)
 294                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 295                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 296
 297                 if (readl(_ISR(i2c)) & ISR_SAD) {
 298                         if (i2c_debug > 0)
 299                                 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
 300                         goto out;
 301                 }
 302
 303                 /* wait for unit and bus being not busy, and we also do a
 304                  * quick check of the i2c lines themselves to ensure they've
 305                  * gone high...
 306                  */
 307                 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
 308                         if (i2c_debug > 0)
 309                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
 310                         return 1;
 311                 }
 312
 313                 msleep(1);
 314         }
 315
 316         if (i2c_debug > 0)
 317                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
 318  out:
 319         return 0;
 320 }
 321
 322 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
 323 {
 324         if (i2c_debug)
 325                 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
 326
 327         if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
 328                 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
 329                 if (!i2c_pxa_wait_master(i2c)) {
 330                         dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
 331                         return I2C_RETRY;
 332                 }
 333         }
 334
 335         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
 336         return 0;
 337 }
 338
 339 #ifdef CONFIG_I2C_PXA_SLAVE
 340 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
 341 {
 342         unsigned long timeout = jiffies + HZ*1;
 343
 344         /* wait for stop */
 345
 346         show_state(i2c);
 347
 348         while (time_before(jiffies, timeout)) {
 349                 if (i2c_debug > 1)
 350                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 351                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
 352
 353                 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
 354                     (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
 355                     (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
 356                         if (i2c_debug > 1)
 357                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
 358                         return 1;
 359                 }
 360
 361                 msleep(1);
 362         }
 363
 364         if (i2c_debug > 0)
 365                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
 366         return 0;
 367 }
 368
 369 /*
 370  * clear the hold on the bus, and take of anything else
 371  * that has been configured
 372  */
 373 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
 374 {
 375         show_state(i2c);
 376
 377         if (errcode < 0) {
 378                 udelay(100);   /* simple delay */
 379         } else {
 380                 /* we need to wait for the stop condition to end */
 381
 382                 /* if we where in stop, then clear... */
 383                 if (readl(_ICR(i2c)) & ICR_STOP) {
 384                         udelay(100);
 385                         writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
 386                 }
 387
 388                 if (!i2c_pxa_wait_slave(i2c)) {
 389                         dev_err(&i2c->adap.dev, "%s: wait timedout\n",
 390                                 __func__);
 391                         return;
 392                 }
 393         }
 394
 395         writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
 396         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 397
 398         if (i2c_debug) {
 399                 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
 400                 decode_ICR(readl(_ICR(i2c)));
 401         }
 402 }
 403 #else
 404 #define i2c_pxa_set_slave(i2c, err)     do { } while (0)
 405 #endif
 406
 407 static void i2c_pxa_reset(struct pxa_i2c *i2c)
 408 {
 409         pr_debug("Resetting I2C Controller Unit\n");
 410
 411         /* abort any transfer currently under way */
 412         i2c_pxa_abort(i2c);
 413
 414         /* reset according to 9.8 */
 415         writel(ICR_UR, _ICR(i2c));
 416         writel(I2C_ISR_INIT, _ISR(i2c));
 417         writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
 418
 419         writel(i2c->slave_addr, _ISAR(i2c));
 420
 421         /* set control register values */
 422         writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
 423
 424 #ifdef CONFIG_I2C_PXA_SLAVE
 425         dev_info(&i2c->adap.dev, "Enabling slave mode\n");
 426         writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
 427 #endif
 428
 429         i2c_pxa_set_slave(i2c, 0);
 430
 431         /* enable unit */
 432         writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
 433         udelay(100);
 434 }
 435
 436
 437 #ifdef CONFIG_I2C_PXA_SLAVE
 438 /*
 439  * PXA I2C Slave mode
 440  */
 441
 442 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
 443 {
 444         if (isr & ISR_BED) {
 445                 /* what should we do here? */
 446         } else {
 447                 int ret = 0;
 448
 449                 if (i2c->slave != NULL)
 450                         ret = i2c->slave->read(i2c->slave->data);
 451
 452                 writel(ret, _IDBR(i2c));
 453                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));   /* allow next byte */
 454         }
 455 }
 456
 457 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
 458 {
 459         unsigned int byte = readl(_IDBR(i2c));
 460
 461         if (i2c->slave != NULL)
 462                 i2c->slave->write(i2c->slave->data, byte);
 463
 464         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 465 }
 466
 467 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
 468 {
 469         int timeout;
 470
 471         if (i2c_debug > 0)
 472                 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
 473                        (isr & ISR_RWM) ? 'r' : 't');
 474
 475         if (i2c->slave != NULL)
 476                 i2c->slave->event(i2c->slave->data,
 477                                  (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
 478
 479         /*
 480          * slave could interrupt in the middle of us generating a
 481          * start condition... if this happens, we'd better back off
 482          * and stop holding the poor thing up
 483          */
 484         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
 485         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 486
 487         timeout = 0x10000;
 488
 489         while (1) {
 490                 if ((readl(_IBMR(i2c)) & 2) == 2)
 491                         break;
 492
 493                 timeout--;
 494
 495                 if (timeout <= 0) {
 496                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
 497                         break;
 498                 }
 499         }
 500
 501         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 502 }
 503
 504 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
 505 {
 506         if (i2c_debug > 2)
 507                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
 508
 509         if (i2c->slave != NULL)
 510                 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
 511
 512         if (i2c_debug > 2)
 513                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
 514
 515         /*
 516          * If we have a master-mode message waiting,
 517          * kick it off now that the slave has completed.
 518          */
 519         if (i2c->msg)
 520                 i2c_pxa_master_complete(i2c, I2C_RETRY);
 521 }
 522 #else
 523 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
 524 {
 525         if (isr & ISR_BED) {
 526                 /* what should we do here? */
 527         } else {
 528                 writel(0, _IDBR(i2c));
 529                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
 530         }
 531 }
 532
 533 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
 534 {
 535         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
 536 }
 537
 538 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
 539 {
 540         int timeout;
 541
 542         /*
 543          * slave could interrupt in the middle of us generating a
 544          * start condition... if this happens, we'd better back off
 545          * and stop holding the poor thing up
 546          */
 547         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
 548         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
 549
 550         timeout = 0x10000;
 551
 552         while (1) {
 553                 if ((readl(_IBMR(i2c)) & 2) == 2)
 554                         break;
 555
 556                 timeout--;
 557
 558                 if (timeout <= 0) {
 559                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
 560                         break;
 561                 }
 562         }
 563
 564         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
 565 }
 566
 567 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
 568 {
 569         if (i2c->msg)
 570                 i2c_pxa_master_complete(i2c, I2C_RETRY);
 571 }
 572 #endif
 573
 574 /*
 575  * PXA I2C Master mode
 576  */
 577
 578 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
 579 {
 580         unsigned int addr = (msg->addr & 0x7f) << 1;
 581
 582         if (msg->flags & I2C_M_RD)
 583                 addr |= 1;
 584
 585         return addr;
 586 }
 587
 588 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
 589 {
 590         u32 icr;
 591
 592         /*
 593          * Step 1: target slave address into IDBR
 594          */
 595         writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
 596
 597         /*
 598          * Step 2: initiate the write.
 599          */
 600         icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
 601         writel(icr | ICR_START | ICR_TB, _ICR(i2c));
 602 }
 603
 604 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
 605 {
 606         u32 icr;
 607
 608         /*
 609          * Clear the STOP and ACK flags
 610          */
 611         icr = readl(_ICR(i2c));
 612         icr &= ~(ICR_STOP | ICR_ACKNAK);
 613         writel(icr, _ICR(i2c));
 614 }
 615
 616 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
 617 {
 618         /* make timeout the same as for interrupt based functions */
 619         long timeout = 2 * DEF_TIMEOUT;
 620
 621         /*
 622          * Wait for the bus to become free.
 623          */
 624         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
 625                 udelay(1000);
 626                 show_state(i2c);
 627         }
 628
 629         if (timeout < 0) {
 630                 show_state(i2c);
 631                 dev_err(&i2c->adap.dev,
 632                         "i2c_pxa: timeout waiting for bus free\n");
 633                 return I2C_RETRY;
 634         }
 635
 636         /*
 637          * Set master mode.
 638          */
 639         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
 640
 641         return 0;
 642 }
 643
 644 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
 645                                struct i2c_msg *msg, int num)
 646 {
 647         unsigned long timeout = 500000; /* 5 seconds */
 648         int ret = 0;
 649
 650         ret = i2c_pxa_pio_set_master(i2c);
 651         if (ret)
 652                 goto out;
 653
 654         i2c->msg = msg;
 655         i2c->msg_num = num;
 656         i2c->msg_idx = 0;
 657         i2c->msg_ptr = 0;
 658         i2c->irqlogidx = 0;
 659
 660         i2c_pxa_start_message(i2c);
 661
 662         while (i2c->msg_num > 0 && --timeout) {
 663                 i2c_pxa_handler(0, i2c);
 664                 udelay(10);
 665         }
 666
 667         i2c_pxa_stop_message(i2c);
 668
 669         /*
 670          * We place the return code in i2c->msg_idx.
 671          */
 672         ret = i2c->msg_idx;
 673
 674 out:
 675         if (timeout == 0)
 676                 i2c_pxa_scream_blue_murder(i2c, "timeout");
 677
 678         return ret;
 679 }
 680
 681 /*
 682  * We are protected by the adapter bus mutex.
 683  */
 684 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 685 {
 686         long timeout;
 687         int ret;
 688
 689         /*
 690          * Wait for the bus to become free.
 691          */
 692         ret = i2c_pxa_wait_bus_not_busy(i2c);
 693         if (ret) {
 694                 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
 695                 goto out;
 696         }
 697
 698         /*
 699          * Set master mode.
 700          */
 701         ret = i2c_pxa_set_master(i2c);
 702         if (ret) {
 703                 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
 704                 goto out;
 705         }
 706
 707         spin_lock_irq(&i2c->lock);
 708
 709         i2c->msg = msg;
 710         i2c->msg_num = num;
 711         i2c->msg_idx = 0;
 712         i2c->msg_ptr = 0;
 713         i2c->irqlogidx = 0;
 714
 715         i2c_pxa_start_message(i2c);
 716
 717         spin_unlock_irq(&i2c->lock);
 718
 719         /*
 720          * The rest of the processing occurs in the interrupt handler.
 721          */
 722         timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
 723         i2c_pxa_stop_message(i2c);
 724
 725         /*
 726          * We place the return code in i2c->msg_idx.
 727          */
 728         ret = i2c->msg_idx;
 729
 730         if (timeout == 0)
 731                 i2c_pxa_scream_blue_murder(i2c, "timeout");
 732
 733  out:
 734         return ret;
 735 }
 736
 737 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
 738                             struct i2c_msg msgs[], int num)
 739 {
 740         struct pxa_i2c *i2c = adap->algo_data;
 741         int ret, i;
 742
 743         /* If the I2C controller is disabled we need to reset it
 744           (probably due to a suspend/resume destroying state). We do
 745           this here as we can then avoid worrying about resuming the
 746           controller before its users. */
 747         if (!(readl(_ICR(i2c)) & ICR_IUE))
 748                 i2c_pxa_reset(i2c);
 749
 750         for (i = adap->retries; i >= 0; i--) {
 751                 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
 752                 if (ret != I2C_RETRY)
 753                         goto out;
 754
 755                 if (i2c_debug)
 756                         dev_dbg(&adap->dev, "Retrying transmission\n");
 757                 udelay(100);
 758         }
 759         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 760         ret = -EREMOTEIO;
 761  out:
 762         i2c_pxa_set_slave(i2c, ret);
 763         return ret;
 764 }
 765
 766 /*
 767  * i2c_pxa_master_complete - complete the message and wake up.
 768  */
 769 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
 770 {
 771         i2c->msg_ptr = 0;
 772         i2c->msg = NULL;
 773         i2c->msg_idx ++;
 774         i2c->msg_num = 0;
 775         if (ret)
 776                 i2c->msg_idx = ret;
 777         if (!i2c->use_pio)
 778                 wake_up(&i2c->wait);
 779 }
 780
 781 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
 782 {
 783         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
 784
 785  again:
 786         /*
 787          * If ISR_ALD is set, we lost arbitration.
 788          */
 789         if (isr & ISR_ALD) {
 790                 /*
 791                  * Do we need to do anything here?  The PXA docs
 792                  * are vague about what happens.
 793                  */
 794                 i2c_pxa_scream_blue_murder(i2c, "ALD set");
 795
 796                 /*
 797                  * We ignore this error.  We seem to see spurious ALDs
 798                  * for seemingly no reason.  If we handle them as I think
 799                  * they should, we end up causing an I2C error, which
 800                  * is painful for some systems.
 801                  */
 802                 return; /* ignore */
 803         }
 804
 805         if (isr & ISR_BED) {
 806                 int ret = BUS_ERROR;
 807
 808                 /*
 809                  * I2C bus error - either the device NAK'd us, or
 810                  * something more serious happened.  If we were NAK'd
 811                  * on the initial address phase, we can retry.
 812                  */
 813                 if (isr & ISR_ACKNAK) {
 814                         if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
 815                                 ret = I2C_RETRY;
 816                         else
 817                                 ret = XFER_NAKED;
 818                 }
 819                 i2c_pxa_master_complete(i2c, ret);
 820         } else if (isr & ISR_RWM) {
 821                 /*
 822                  * Read mode.  We have just sent the address byte, and
 823                  * now we must initiate the transfer.
 824                  */
 825                 if (i2c->msg_ptr == i2c->msg->len - 1 &&
 826                     i2c->msg_idx == i2c->msg_num - 1)
 827                         icr |= ICR_STOP | ICR_ACKNAK;
 828
 829                 icr |= ICR_ALDIE | ICR_TB;
 830         } else if (i2c->msg_ptr < i2c->msg->len) {
 831                 /*
 832                  * Write mode.  Write the next data byte.
 833                  */
 834                 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
 835
 836                 icr |= ICR_ALDIE | ICR_TB;
 837
 838                 /*
 839                  * If this is the last byte of the last message, send
 840                  * a STOP.
 841                  */
 842                 if (i2c->msg_ptr == i2c->msg->len &&
 843                     i2c->msg_idx == i2c->msg_num - 1)
 844                         icr |= ICR_STOP;
 845         } else if (i2c->msg_idx < i2c->msg_num - 1) {
 846                 /*
 847                  * Next segment of the message.
 848                  */
 849                 i2c->msg_ptr = 0;
 850                 i2c->msg_idx ++;
 851                 i2c->msg++;
 852
 853                 /*
 854                  * If we aren't doing a repeated start and address,
 855                  * go back and try to send the next byte.  Note that
 856                  * we do not support switching the R/W direction here.
 857                  */
 858                 if (i2c->msg->flags & I2C_M_NOSTART)
 859                         goto again;
 860
 861                 /*
 862                  * Write the next address.
 863                  */
 864                 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
 865
 866                 /*
 867                  * And trigger a repeated start, and send the byte.
 868                  */
 869                 icr &= ~ICR_ALDIE;
 870                 icr |= ICR_START | ICR_TB;
 871         } else {
 872                 if (i2c->msg->len == 0) {
 873                         /*
 874                          * Device probes have a message length of zero
 875                          * and need the bus to be reset before it can
 876                          * be used again.
 877                          */
 878                         i2c_pxa_reset(i2c);
 879                 }
 880                 i2c_pxa_master_complete(i2c, 0);
 881         }
 882
 883         i2c->icrlog[i2c->irqlogidx-1] = icr;
 884
 885         writel(icr, _ICR(i2c));
 886         show_state(i2c);
 887 }
 888
 889 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
 890 {
 891         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
 892
 893         /*
 894          * Read the byte.
 895          */
 896         i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
 897
 898         if (i2c->msg_ptr < i2c->msg->len) {
 899                 /*
 900                  * If this is the last byte of the last
 901                  * message, send a STOP.
 902                  */
 903                 if (i2c->msg_ptr == i2c->msg->len - 1)
 904                         icr |= ICR_STOP | ICR_ACKNAK;
 905
 906                 icr |= ICR_ALDIE | ICR_TB;
 907         } else {
 908                 i2c_pxa_master_complete(i2c, 0);
 909         }
 910
 911         i2c->icrlog[i2c->irqlogidx-1] = icr;
 912
 913         writel(icr, _ICR(i2c));
 914 }
 915
 916 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
 917 {
 918         struct pxa_i2c *i2c = dev_id;
 919         u32 isr = readl(_ISR(i2c));
 920
 921         if (i2c_debug > 2 && 0) {
 922                 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
 923                         __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
 924                 decode_ISR(isr);
 925         }
 926
 927         if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
 928                 i2c->isrlog[i2c->irqlogidx++] = isr;
 929
 930         show_state(i2c);
 931
 932         /*
 933          * Always clear all pending IRQs.
 934          */
 935         writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
 936
 937         if (isr & ISR_SAD)
 938                 i2c_pxa_slave_start(i2c, isr);
 939         if (isr & ISR_SSD)
 940                 i2c_pxa_slave_stop(i2c);
 941
 942         if (i2c_pxa_is_slavemode(i2c)) {
 943                 if (isr & ISR_ITE)
 944                         i2c_pxa_slave_txempty(i2c, isr);
 945                 if (isr & ISR_IRF)
 946                         i2c_pxa_slave_rxfull(i2c, isr);
 947         } else if (i2c->msg) {
 948                 if (isr & ISR_ITE)
 949                         i2c_pxa_irq_txempty(i2c, isr);
 950                 if (isr & ISR_IRF)
 951                         i2c_pxa_irq_rxfull(i2c, isr);
 952         } else {
 953                 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
 954         }
 955
 956         return IRQ_HANDLED;
 957 }
 958
 959
 960 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 961 {
 962         struct pxa_i2c *i2c = adap->algo_data;
 963         int ret, i;
 964
 965         for (i = adap->retries; i >= 0; i--) {
 966                 ret = i2c_pxa_do_xfer(i2c, msgs, num);
 967                 if (ret != I2C_RETRY)
 968                         goto out;
 969
 970                 if (i2c_debug)
 971                         dev_dbg(&adap->dev, "Retrying transmission\n");
 972                 udelay(100);
 973         }
 974         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
 975         ret = -EREMOTEIO;
 976  out:
 977         i2c_pxa_set_slave(i2c, ret);
 978         return ret;
 979 }
 980
 981 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
 982 {
 983         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 984 }
 985
 986 static const struct i2c_algorithm i2c_pxa_algorithm = {
 987         .master_xfer    = i2c_pxa_xfer,
 988         .functionality  = i2c_pxa_functionality,
 989 };
 990
 991 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
 992         .master_xfer    = i2c_pxa_pio_xfer,
 993         .functionality  = i2c_pxa_functionality,
 994 };
 995
 996 static int i2c_pxa_probe(struct platform_device *dev)
 997 {
 998         struct pxa_i2c *i2c;
 999         struct resource *res;
1000         struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
1001         struct platform_device_id *id = platform_get_device_id(dev);
1002         int ret;
1003         int irq;
1004
1005         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1006         irq = platform_get_irq(dev, 0);
1007         if (res == NULL || irq < 0)
1008                 return -ENODEV;
1009
1010         if (!request_mem_region(res->start, resource_size(res), res->name))
1011                 return -ENOMEM;
1012
1013         i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1014         if (!i2c) {
1015                 ret = -ENOMEM;
1016                 goto emalloc;
1017         }
1018
1019         i2c->adap.owner   = THIS_MODULE;
1020         i2c->adap.retries = 5;
1021
1022         spin_lock_init(&i2c->lock);
1023         init_waitqueue_head(&i2c->wait);
1024
1025         /*
1026          * If "dev->id" is negative we consider it as zero.
1027          * The reason to do so is to avoid sysfs names that only make
1028          * sense when there are multiple adapters.
1029          */
1030         i2c->adap.nr = dev->id != -1 ? dev->id : 0;
1031         snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
1032                  i2c->adap.nr);
1033
1034         i2c->clk = clk_get(&dev->dev, NULL);
1035         if (IS_ERR(i2c->clk)) {
1036                 ret = PTR_ERR(i2c->clk);
1037                 goto eclk;
1038         }
1039
1040         i2c->reg_base = ioremap(res->start, resource_size(res));
1041         if (!i2c->reg_base) {
1042                 ret = -EIO;
1043                 goto eremap;
1044         }
1045         i2c->reg_shift = REG_SHIFT(id->driver_data);
1046
1047         i2c->iobase = res->start;
1048         i2c->iosize = resource_size(res);
1049
1050         i2c->irq = irq;
1051
1052         i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1053
1054 #ifdef CONFIG_I2C_PXA_SLAVE
1055         if (plat) {
1056                 i2c->slave_addr = plat->slave_addr;
1057                 i2c->slave = plat->slave;
1058         }
1059 #endif
1060
1061         clk_enable(i2c->clk);
1062
1063         if (plat) {
1064                 i2c->adap.class = plat->class;
1065                 i2c->use_pio = plat->use_pio;
1066                 i2c->fast_mode = plat->fast_mode;
1067         }
1068
1069         if (i2c->use_pio) {
1070                 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1071         } else {
1072                 i2c->adap.algo = &i2c_pxa_algorithm;
1073                 ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
1074                                   i2c->adap.name, i2c);
1075                 if (ret)
1076                         goto ereqirq;
1077         }
1078
1079         i2c_pxa_reset(i2c);
1080
1081         i2c->adap.algo_data = i2c;
1082         i2c->adap.dev.parent = &dev->dev;
1083
1084         ret = i2c_add_numbered_adapter(&i2c->adap);
1085         if (ret < 0) {
1086                 printk(KERN_INFO "I2C: Failed to add bus\n");
1087                 goto eadapt;
1088         }
1089
1090         platform_set_drvdata(dev, i2c);
1091
1092 #ifdef CONFIG_I2C_PXA_SLAVE
1093         printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1094                dev_name(&i2c->adap.dev), i2c->slave_addr);
1095 #else
1096         printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1097                dev_name(&i2c->adap.dev));
1098 #endif
1099         return 0;
1100
1101 eadapt:
1102         if (!i2c->use_pio)
1103                 free_irq(irq, i2c);
1104 ereqirq:
1105         clk_disable(i2c->clk);
1106         iounmap(i2c->reg_base);
1107 eremap:
1108         clk_put(i2c->clk);
1109 eclk:
1110         kfree(i2c);
1111 emalloc:
1112         release_mem_region(res->start, resource_size(res));
1113         return ret;
1114 }
1115
1116 static int __exit i2c_pxa_remove(struct platform_device *dev)
1117 {
1118         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1119
1120         platform_set_drvdata(dev, NULL);
1121
1122         i2c_del_adapter(&i2c->adap);
1123         if (!i2c->use_pio)
1124                 free_irq(i2c->irq, i2c);
1125
1126         clk_disable(i2c->clk);
1127         clk_put(i2c->clk);
1128
1129         iounmap(i2c->reg_base);
1130         release_mem_region(i2c->iobase, i2c->iosize);
1131         kfree(i2c);
1132
1133         return 0;
1134 }
1135
1136 #ifdef CONFIG_PM
1137 static int i2c_pxa_suspend_noirq(struct device *dev)
1138 {
1139         struct platform_device *pdev = to_platform_device(dev);
1140         struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1141
1142         clk_disable(i2c->clk);
1143
1144         return 0;
1145 }
1146
1147 static int i2c_pxa_resume_noirq(struct device *dev)
1148 {
1149         struct platform_device *pdev = to_platform_device(dev);
1150         struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1151
1152         clk_enable(i2c->clk);
1153         i2c_pxa_reset(i2c);
1154
1155         return 0;
1156 }
1157
1158 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1159         .suspend_noirq = i2c_pxa_suspend_noirq,
1160         .resume_noirq = i2c_pxa_resume_noirq,
1161 };
1162
1163 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1164 #else
1165 #define I2C_PXA_DEV_PM_OPS NULL
1166 #endif
1167
1168 static struct platform_driver i2c_pxa_driver = {
1169         .probe          = i2c_pxa_probe,
1170         .remove         = __exit_p(i2c_pxa_remove),
1171         .driver         = {
1172                 .name   = "pxa2xx-i2c",
1173                 .owner  = THIS_MODULE,
1174                 .pm     = I2C_PXA_DEV_PM_OPS,
1175         },
1176         .id_table       = i2c_pxa_id_table,
1177 };
1178
1179 static int __init i2c_adap_pxa_init(void)
1180 {
1181         return platform_driver_register(&i2c_pxa_driver);
1182 }
1183
1184 static void __exit i2c_adap_pxa_exit(void)
1185 {
1186         platform_driver_unregister(&i2c_pxa_driver);
1187 }
1188
1189 MODULE_LICENSE("GPL");
1190 MODULE_ALIAS("platform:pxa2xx-i2c");
1191
1192 subsys_initcall(i2c_adap_pxa_init);
1193 module_exit(i2c_adap_pxa_exit);