cpu/mpc8xx/i2c.c

   1 /*
   2  * (C) Copyright 2000
   3  * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
   4  *
   5  * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   6  * Marius Groeger <mgroeger@sysgo.de>
   7  *
   8  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  *
  26  * Back ported to the 8xx platform (from the 8260 platform) by
  27  * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
  28  */
  29
  30 #include <common.h>
  31
  32 #ifdef CONFIG_HARD_I2C
  33
  34 #include <commproc.h>
  35 #include <i2c.h>
  36 #ifdef CONFIG_LWMON
  37 #include <watchdog.h>
  38 #endif
  39
  40 DECLARE_GLOBAL_DATA_PTR;
  41
  42 /* define to enable debug messages */
  43 #undef  DEBUG_I2C
  44
  45 /*-----------------------------------------------------------------------
  46  * Set default values
  47  */
  48 #ifndef CFG_I2C_SPEED
  49 #define CFG_I2C_SPEED   50000
  50 #endif
  51
  52 #ifndef CFG_I2C_SLAVE
  53 #define CFG_I2C_SLAVE   0xFE
  54 #endif
  55 /*-----------------------------------------------------------------------
  56  */
  57
  58 /* tx/rx timeout (we need the i2c early, so we don't use get_timer()) */
  59 #define TOUT_LOOP 1000000
  60
  61 #define NUM_RX_BDS 4
  62 #define NUM_TX_BDS 4
  63 #define MAX_TX_SPACE 256
  64 #define I2C_RXTX_LEN 128        /* maximum tx/rx buffer length */
  65
  66 typedef struct I2C_BD
  67 {
  68   unsigned short status;
  69   unsigned short length;
  70   unsigned char *addr;
  71 } I2C_BD;
  72 #define BD_I2C_TX_START 0x0400  /* special status for i2c: Start condition */
  73
  74 #define BD_I2C_TX_CL    0x0001  /* collision error */
  75 #define BD_I2C_TX_UN    0x0002  /* underflow error */
  76 #define BD_I2C_TX_NAK   0x0004  /* no acknowledge error */
  77 #define BD_I2C_TX_ERR   (BD_I2C_TX_NAK|BD_I2C_TX_UN|BD_I2C_TX_CL)
  78
  79 #define BD_I2C_RX_ERR   BD_SC_OV
  80
  81 typedef void (*i2c_ecb_t)(int, int);    /* error callback function */
  82
  83 /* This structure keeps track of the bd and buffer space usage. */
  84 typedef struct i2c_state {
  85         int             rx_idx;         /* index   to next free Rx BD */
  86         int             tx_idx;         /* index   to next free Tx BD */
  87         void            *rxbd;          /* pointer to next free Rx BD */
  88         void            *txbd;          /* pointer to next free Tx BD */
  89         int             tx_space;       /* number  of Tx bytes left   */
  90         unsigned char   *tx_buf;        /* pointer to free Tx area    */
  91         i2c_ecb_t       err_cb;         /* error callback function    */
  92 } i2c_state_t;
  93
  94
  95 /* flags for i2c_send() and i2c_receive() */
  96 #define I2CF_ENABLE_SECONDARY   0x01    /* secondary_address is valid           */
  97 #define I2CF_START_COND         0x02    /* tx: generate start condition         */
  98 #define I2CF_STOP_COND          0x04    /* tx: generate stop  condition         */
  99
 100 /* return codes */
 101 #define I2CERR_NO_BUFFERS       0x01    /* no more BDs or buffer space          */
 102 #define I2CERR_MSG_TOO_LONG     0x02    /* tried to send/receive to much data   */
 103 #define I2CERR_TIMEOUT          0x03    /* timeout in i2c_doio()                */
 104 #define I2CERR_QUEUE_EMPTY      0x04    /* i2c_doio called without send/receive */
 105
 106 /* error callback flags */
 107 #define I2CECB_RX_ERR           0x10    /* this is a receive error              */
 108 #define     I2CECB_RX_ERR_OV    0x02    /* receive overrun error                */
 109 #define     I2CECB_RX_MASK      0x0f    /* mask for error bits                  */
 110 #define I2CECB_TX_ERR           0x20    /* this is a transmit error             */
 111 #define     I2CECB_TX_CL        0x01    /* transmit collision error             */
 112 #define     I2CECB_TX_UN        0x02    /* transmit underflow error             */
 113 #define     I2CECB_TX_NAK       0x04    /* transmit no ack error                */
 114 #define     I2CECB_TX_MASK      0x0f    /* mask for error bits                  */
 115 #define I2CECB_TIMEOUT          0x40    /* this is a timeout error              */
 116
 117 #ifdef DEBUG_I2C
 118 #define PRINTD(x) printf x
 119 #else
 120 #define PRINTD(x)
 121 #endif
 122
 123 /*
 124  * Returns the best value of I2BRG to meet desired clock speed of I2C with
 125  * input parameters (clock speed, filter, and predivider value).
 126  * It returns computer speed value and the difference between it and desired
 127  * speed.
 128  */
 129 static inline int
 130 i2c_roundrate(int hz, int speed, int filter, int modval,
 131                 int *brgval, int *totspeed)
 132 {
 133     int moddiv = 1 << (5-(modval & 3)), brgdiv, div;
 134
 135     PRINTD(("\t[I2C] trying hz=%d, speed=%d, filter=%d, modval=%d\n",
 136         hz, speed, filter, modval));
 137
 138     div = moddiv * speed;
 139     brgdiv = (hz + div - 1) / div;
 140
 141     PRINTD(("\t\tmoddiv=%d, brgdiv=%d\n", moddiv, brgdiv));
 142
 143     *brgval = ((brgdiv + 1) / 2) - 3 - (2*filter);
 144
 145     if ((*brgval < 0) || (*brgval > 255)) {
 146           PRINTD(("\t\trejected brgval=%d\n", *brgval));
 147           return -1;
 148     }
 149
 150     brgdiv = 2 * (*brgval + 3 + (2 * filter));
 151     div = moddiv * brgdiv ;
 152     *totspeed = hz / div;
 153
 154     PRINTD(("\t\taccepted brgval=%d, totspeed=%d\n", *brgval, *totspeed));
 155
 156     return  0;
 157 }
 158
 159 /*
 160  * Sets the I2C clock predivider and divider to meet required clock speed.
 161  */
 162 static int
 163 i2c_setrate (int hz, int speed)
 164 {
 165         immap_t         *immap = (immap_t *) CFG_IMMR;
 166         volatile i2c8xx_t *i2c = (i2c8xx_t *) & immap->im_i2c;
 167         int             brgval,
 168                         modval,         /* 0-3 */
 169                         bestspeed_diff = speed,
 170                         bestspeed_brgval = 0,
 171                         bestspeed_modval = 0,
 172                         bestspeed_filter = 0,
 173                         totspeed,
 174                         filter = 0;     /* Use this fixed value */
 175
 176         for (modval = 0; modval < 4; modval++) {
 177                 if (i2c_roundrate(hz,speed,filter,modval,&brgval,&totspeed) == 0) {
 178                         int diff = speed - totspeed;
 179
 180                         if ((diff >= 0) && (diff < bestspeed_diff)) {
 181                                 bestspeed_diff = diff;
 182                                 bestspeed_modval = modval;
 183                                 bestspeed_brgval = brgval;
 184                                 bestspeed_filter = filter;
 185                         }
 186                 }
 187         }
 188
 189         PRINTD (("[I2C] Best is:\n"));
 190         PRINTD (("[I2C] CPU=%dhz RATE=%d F=%d I2MOD=%08x I2BRG=%08x DIFF=%dhz\n",
 191                 hz,
 192                 speed,
 193                 bestspeed_filter,
 194                 bestspeed_modval,
 195                 bestspeed_brgval,
 196                 bestspeed_diff));
 197
 198         i2c->i2c_i2mod |= ((bestspeed_modval & 3) << 1) | (bestspeed_filter << 3);
 199         i2c->i2c_i2brg = bestspeed_brgval & 0xff;
 200
 201         PRINTD (("[I2C] i2mod=%08x i2brg=%08x\n", i2c->i2c_i2mod,
 202                          i2c->i2c_i2brg));
 203
 204         return 1;
 205 }
 206
 207 void
 208 i2c_init(int speed, int slaveaddr)
 209 {
 210         volatile immap_t *immap = (immap_t *)CFG_IMMR ;
 211         volatile cpm8xx_t *cp = (cpm8xx_t *)&immap->im_cpm;
 212         volatile i2c8xx_t *i2c  = (i2c8xx_t *)&immap->im_i2c;
 213         volatile iic_t *iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
 214         ulong rbase, tbase;
 215         volatile I2C_BD *rxbd, *txbd;
 216         uint dpaddr;
 217
 218 #ifdef CFG_I2C_INIT_BOARD
 219         /* call board specific i2c bus reset routine before accessing the   */
 220         /* environment, which might be in a chip on that bus. For details   */
 221         /* about this problem see doc/I2C_Edge_Conditions.                  */
 222         i2c_init_board();
 223 #endif
 224
 225 #ifdef CFG_I2C_UCODE_PATCH
 226         iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
 227 #else
 228         /* Disable relocation */
 229         iip->iic_rpbase = 0;
 230 #endif
 231
 232 #ifdef CFG_ALLOC_DPRAM
 233         dpaddr = iip->iic_rbase;
 234         if (dpaddr == 0) {
 235             /* need to allocate dual port ram */
 236             dpaddr = dpram_alloc_align(
 237                 (NUM_RX_BDS * sizeof(I2C_BD)) + (NUM_TX_BDS * sizeof(I2C_BD)) +
 238                 MAX_TX_SPACE, 8);
 239         }
 240 #else
 241         dpaddr = CPM_I2C_BASE;
 242 #endif
 243
 244         /*
 245          * initialise data in dual port ram:
 246          *
 247          * dpaddr->rbase -> rx BD         (NUM_RX_BDS * sizeof(I2C_BD) bytes)
 248          *         tbase -> tx BD         (NUM_TX_BDS * sizeof(I2C_BD) bytes)
 249          *                  tx buffer     (MAX_TX_SPACE bytes)
 250          */
 251
 252         rbase = dpaddr;
 253         tbase = rbase + NUM_RX_BDS * sizeof(I2C_BD);
 254
 255         /* Initialize Port B I2C pins. */
 256         cp->cp_pbpar |= 0x00000030;
 257         cp->cp_pbdir |= 0x00000030;
 258         cp->cp_pbodr |= 0x00000030;
 259
 260         /* Disable interrupts */
 261         i2c->i2c_i2mod = 0x00;
 262         i2c->i2c_i2cmr = 0x00;
 263         i2c->i2c_i2cer = 0xff;
 264         i2c->i2c_i2add = slaveaddr;
 265
 266         /*
 267          * Set the I2C BRG Clock division factor from desired i2c rate
 268          * and current CPU rate (we assume sccr dfbgr field is 0;
 269          * divide BRGCLK by 1)
 270          */
 271         PRINTD(("[I2C] Setting rate...\n"));
 272         i2c_setrate (gd->cpu_clk, CFG_I2C_SPEED) ;
 273
 274         /* Set I2C controller in master mode */
 275         i2c->i2c_i2com = 0x01;
 276
 277         /* Set SDMA bus arbitration level to 5 (SDCR) */
 278         immap->im_siu_conf.sc_sdcr = 0x0001 ;
 279
 280         /* Initialize Tx/Rx parameters */
 281         iip->iic_rbase = rbase;
 282         iip->iic_tbase = tbase;
 283         rxbd = (I2C_BD *)((unsigned char *)&cp->cp_dpmem[iip->iic_rbase]);
 284         txbd = (I2C_BD *)((unsigned char *)&cp->cp_dpmem[iip->iic_tbase]);
 285
 286         PRINTD(("[I2C] rbase = %04x\n", iip->iic_rbase));
 287         PRINTD(("[I2C] tbase = %04x\n", iip->iic_tbase));
 288         PRINTD(("[I2C] rxbd = %08x\n", (int)rxbd));
 289         PRINTD(("[I2C] txbd = %08x\n", (int)txbd));
 290
 291         /* Set big endian byte order */
 292         iip->iic_tfcr = 0x10;
 293         iip->iic_rfcr = 0x10;
 294
 295         /* Set maximum receive size. */
 296         iip->iic_mrblr = I2C_RXTX_LEN;
 297
 298 #ifdef CFG_I2C_UCODE_PATCH
 299         /*
 300          *  Initialize required parameters if using microcode patch.
 301          */
 302         iip->iic_rbptr  = iip->iic_rbase;
 303         iip->iic_tbptr  = iip->iic_tbase;
 304         iip->iic_rstate = 0;
 305         iip->iic_tstate = 0;
 306 #else
 307         cp->cp_cpcr = mk_cr_cmd(CPM_CR_CH_I2C, CPM_CR_INIT_TRX) | CPM_CR_FLG;
 308         do {
 309                 __asm__ __volatile__ ("eieio");
 310         } while (cp->cp_cpcr & CPM_CR_FLG);
 311 #endif
 312
 313         /* Clear events and interrupts */
 314         i2c->i2c_i2cer = 0xff;
 315         i2c->i2c_i2cmr = 0x00;
 316 }
 317
 318 static void
 319 i2c_newio(i2c_state_t *state)
 320 {
 321         volatile immap_t *immap = (immap_t *)CFG_IMMR ;
 322         volatile cpm8xx_t *cp = (cpm8xx_t *)&immap->im_cpm;
 323         volatile iic_t *iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
 324
 325         PRINTD(("[I2C] i2c_newio\n"));
 326
 327 #ifdef CFG_I2C_UCODE_PATCH
 328         iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
 329 #endif
 330         state->rx_idx = 0;
 331         state->tx_idx = 0;
 332         state->rxbd = (void*)&cp->cp_dpmem[iip->iic_rbase];
 333         state->txbd = (void*)&cp->cp_dpmem[iip->iic_tbase];
 334         state->tx_space = MAX_TX_SPACE;
 335         state->tx_buf = (uchar*)state->txbd + NUM_TX_BDS * sizeof(I2C_BD);
 336         state->err_cb = NULL;
 337
 338         PRINTD(("[I2C] rxbd = %08x\n", (int)state->rxbd));
 339         PRINTD(("[I2C] txbd = %08x\n", (int)state->txbd));
 340         PRINTD(("[I2C] tx_buf = %08x\n", (int)state->tx_buf));
 341
 342         /* clear the buffer memory */
 343         memset((char *)state->tx_buf, 0, MAX_TX_SPACE);
 344 }
 345
 346 static int
 347 i2c_send(i2c_state_t *state,
 348          unsigned char address,
 349          unsigned char secondary_address,
 350          unsigned int flags,
 351          unsigned short size,
 352          unsigned char *dataout)
 353 {
 354         volatile I2C_BD *txbd;
 355         int i,j;
 356
 357         PRINTD(("[I2C] i2c_send add=%02d sec=%02d flag=%02d size=%d\n",
 358                         address, secondary_address, flags, size));
 359
 360         /* trying to send message larger than BD */
 361         if (size > I2C_RXTX_LEN)
 362           return I2CERR_MSG_TOO_LONG;
 363
 364         /* no more free bds */
 365         if (state->tx_idx >= NUM_TX_BDS || state->tx_space < (2 + size))
 366           return I2CERR_NO_BUFFERS;
 367
 368         txbd = (I2C_BD *)state->txbd;
 369         txbd->addr = state->tx_buf;
 370
 371         PRINTD(("[I2C] txbd = %08x\n", (int)txbd));
 372
 373         if (flags & I2CF_START_COND) {
 374                 PRINTD(("[I2C] Formatting addresses...\n"));
 375                 if (flags & I2CF_ENABLE_SECONDARY) {
 376                         txbd->length = size + 2;  /* Length of msg + dest addr */
 377                         txbd->addr[0] = address << 1;
 378                         txbd->addr[1] = secondary_address;
 379                         i = 2;
 380                 } else {
 381                         txbd->length = size + 1;  /* Length of msg + dest addr */
 382                         txbd->addr[0] = address << 1;  /* Write dest addr to BD */
 383                         i = 1;
 384                 }
 385         } else {
 386                 txbd->length = size;  /* Length of message */
 387                 i = 0;
 388         }
 389
 390         /* set up txbd */
 391         txbd->status = BD_SC_READY;
 392         if (flags & I2CF_START_COND)
 393           txbd->status |= BD_I2C_TX_START;
 394         if (flags & I2CF_STOP_COND)
 395           txbd->status |= BD_SC_LAST | BD_SC_WRAP;
 396
 397         /* Copy data to send into buffer */
 398         PRINTD(("[I2C] copy data...\n"));
 399         for(j = 0; j < size; i++, j++)
 400           txbd->addr[i] = dataout[j];
 401
 402         PRINTD(("[I2C] txbd: length=0x%04x status=0x%04x addr[0]=0x%02x addr[1]=0x%02x\n",
 403                    txbd->length,
 404                    txbd->status,
 405                    txbd->addr[0],
 406                    txbd->addr[1]));
 407
 408         /* advance state */
 409         state->tx_buf += txbd->length;
 410         state->tx_space -= txbd->length;
 411         state->tx_idx++;
 412         state->txbd = (void*)(txbd + 1);
 413
 414         return 0;
 415 }
 416
 417 static int
 418 i2c_receive(i2c_state_t *state,
 419             unsigned char address,
 420             unsigned char secondary_address,
 421             unsigned int flags,
 422             unsigned short size_to_expect,
 423             unsigned char *datain)
 424 {
 425         volatile I2C_BD *rxbd, *txbd;
 426
 427         PRINTD(("[I2C] i2c_receive %02d %02d %02d\n", address, secondary_address, flags));
 428
 429         /* Expected to receive too much */
 430         if (size_to_expect > I2C_RXTX_LEN)
 431           return I2CERR_MSG_TOO_LONG;
 432
 433         /* no more free bds */
 434         if (state->tx_idx >= NUM_TX_BDS || state->rx_idx >= NUM_RX_BDS
 435                  || state->tx_space < 2)
 436           return I2CERR_NO_BUFFERS;
 437
 438         rxbd = (I2C_BD *)state->rxbd;
 439         txbd = (I2C_BD *)state->txbd;
 440
 441         PRINTD(("[I2C] rxbd = %08x\n", (int)rxbd));
 442         PRINTD(("[I2C] txbd = %08x\n", (int)txbd));
 443
 444         txbd->addr = state->tx_buf;
 445
 446         /* set up TXBD for destination address */
 447         if (flags & I2CF_ENABLE_SECONDARY) {
 448                 txbd->length = 2;
 449                 txbd->addr[0] = address << 1;   /* Write data */
 450                 txbd->addr[1] = secondary_address;  /* Internal address */
 451                 txbd->status = BD_SC_READY;
 452         } else {
 453                 txbd->length = 1 + size_to_expect;
 454                 txbd->addr[0] = (address << 1) | 0x01;
 455                 txbd->status = BD_SC_READY;
 456                 memset(&txbd->addr[1], 0, txbd->length);
 457         }
 458
 459         /* set up rxbd for reception */
 460         rxbd->status = BD_SC_EMPTY;
 461         rxbd->length = size_to_expect;
 462         rxbd->addr = datain;
 463
 464         txbd->status |= BD_I2C_TX_START;
 465         if (flags & I2CF_STOP_COND) {
 466                 txbd->status |= BD_SC_LAST | BD_SC_WRAP;
 467                 rxbd->status |= BD_SC_WRAP;
 468         }
 469
 470         PRINTD(("[I2C] txbd: length=0x%04x status=0x%04x addr[0]=0x%02x addr[1]=0x%02x\n",
 471                    txbd->length,
 472                    txbd->status,
 473                    txbd->addr[0],
 474                    txbd->addr[1]));
 475         PRINTD(("[I2C] rxbd: length=0x%04x status=0x%04x addr[0]=0x%02x addr[1]=0x%02x\n",
 476                    rxbd->length,
 477                    rxbd->status,
 478                    rxbd->addr[0],
 479                    rxbd->addr[1]));
 480
 481         /* advance state */
 482         state->tx_buf += txbd->length;
 483         state->tx_space -= txbd->length;
 484         state->tx_idx++;
 485         state->txbd = (void*)(txbd + 1);
 486         state->rx_idx++;
 487         state->rxbd = (void*)(rxbd + 1);
 488
 489         return 0;
 490 }
 491
 492
 493 static int i2c_doio(i2c_state_t *state)
 494 {
 495         volatile immap_t *immap = (immap_t *)CFG_IMMR ;
 496         volatile cpm8xx_t *cp = (cpm8xx_t *)&immap->im_cpm;
 497         volatile i2c8xx_t *i2c  = (i2c8xx_t *)&immap->im_i2c;
 498         volatile iic_t *iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
 499         volatile I2C_BD *txbd, *rxbd;
 500         volatile int j = 0;
 501
 502         PRINTD(("[I2C] i2c_doio\n"));
 503
 504 #ifdef CFG_I2C_UCODE_PATCH
 505         iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
 506 #endif
 507
 508         if (state->tx_idx <= 0 && state->rx_idx <= 0) {
 509                 PRINTD(("[I2C] No I/O is queued\n"));
 510                 return I2CERR_QUEUE_EMPTY;
 511         }
 512
 513         iip->iic_rbptr = iip->iic_rbase;
 514         iip->iic_tbptr = iip->iic_tbase;
 515
 516         /* Enable I2C */
 517         PRINTD(("[I2C] Enabling I2C...\n"));
 518         i2c->i2c_i2mod |= 0x01;
 519
 520         /* Begin transmission */
 521         i2c->i2c_i2com |= 0x80;
 522
 523         /* Loop until transmit & receive completed */
 524
 525         if (state->tx_idx > 0) {
 526                 txbd = ((I2C_BD*)state->txbd) - 1;
 527                 PRINTD(("[I2C] Transmitting...(txbd=0x%08lx)\n", (ulong)txbd));
 528                 while((txbd->status & BD_SC_READY) && (j++ < TOUT_LOOP)) {
 529                         if (ctrlc()) {
 530                                 return (-1);
 531                         }
 532                         __asm__ __volatile__ ("eieio");
 533                 }
 534         }
 535
 536         if ((state->rx_idx > 0) && (j < TOUT_LOOP)) {
 537                 rxbd = ((I2C_BD*)state->rxbd) - 1;
 538                 PRINTD(("[I2C] Receiving...(rxbd=0x%08lx)\n", (ulong)rxbd));
 539                 while((rxbd->status & BD_SC_EMPTY) && (j++ < TOUT_LOOP)) {
 540                         if (ctrlc()) {
 541                                 return (-1);
 542                         }
 543                         __asm__ __volatile__ ("eieio");
 544                 }
 545         }
 546
 547         /* Turn off I2C */
 548         i2c->i2c_i2mod &= ~0x01;
 549
 550         if (state->err_cb != NULL) {
 551                 int n, i, b;
 552
 553                 /*
 554                  * if we have an error callback function, look at the
 555                  * error bits in the bd status and pass them back
 556                  */
 557
 558                 if ((n = state->tx_idx) > 0) {
 559                         for (i = 0; i < n; i++) {
 560                                 txbd = ((I2C_BD*)state->txbd) - (n - i);
 561                                 if ((b = txbd->status & BD_I2C_TX_ERR) != 0)
 562                                         (*state->err_cb)(I2CECB_TX_ERR|b, i);
 563                         }
 564                 }
 565
 566                 if ((n = state->rx_idx) > 0) {
 567                         for (i = 0; i < n; i++) {
 568                                 rxbd = ((I2C_BD*)state->rxbd) - (n - i);
 569                                 if ((b = rxbd->status & BD_I2C_RX_ERR) != 0)
 570                                         (*state->err_cb)(I2CECB_RX_ERR|b, i);
 571                         }
 572                 }
 573
 574                 if (j >= TOUT_LOOP)
 575                         (*state->err_cb)(I2CECB_TIMEOUT, 0);
 576         }
 577
 578         return (j >= TOUT_LOOP) ? I2CERR_TIMEOUT : 0;
 579 }
 580
 581 static int had_tx_nak;
 582
 583 static void
 584 i2c_test_callback(int flags, int xnum)
 585 {
 586         if ((flags & I2CECB_TX_ERR) && (flags & I2CECB_TX_NAK))
 587                 had_tx_nak = 1;
 588 }
 589
 590 int i2c_probe(uchar chip)
 591 {
 592         i2c_state_t state;
 593         int rc;
 594         uchar buf[1];
 595
 596         i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE);
 597
 598         i2c_newio(&state);
 599
 600         state.err_cb = i2c_test_callback;
 601         had_tx_nak = 0;
 602
 603         rc = i2c_receive(&state, chip, 0, I2CF_START_COND|I2CF_STOP_COND, 1, buf);
 604
 605         if (rc != 0)
 606                 return (rc);
 607
 608         rc = i2c_doio(&state);
 609
 610         if ((rc != 0) && (rc != I2CERR_TIMEOUT))
 611                 return (rc);
 612
 613         return (had_tx_nak);
 614 }
 615
 616 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 617 {
 618         i2c_state_t state;
 619         uchar xaddr[4];
 620         int rc;
 621
 622 #ifdef CONFIG_LWMON
 623         WATCHDOG_RESET();
 624 #endif
 625
 626         xaddr[0] = (addr >> 24) & 0xFF;
 627         xaddr[1] = (addr >> 16) & 0xFF;
 628         xaddr[2] = (addr >>  8) & 0xFF;
 629         xaddr[3] =  addr        & 0xFF;
 630
 631 #ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
 632         /*
 633          * EEPROM chips that implement "address overflow" are ones like
 634          * Catalyst 24WC04/08/16 which has 9/10/11 bits of address and the
 635          * extra bits end up in the "chip address" bit slots.  This makes
 636          * a 24WC08 (1Kbyte) chip look like four 256 byte chips.
 637          *
 638          * Note that we consider the length of the address field to still
 639          * be one byte because the extra address bits are hidden in the
 640          * chip address.
 641          */
 642          chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
 643 #endif
 644
 645         i2c_newio(&state);
 646
 647         rc = i2c_send(&state, chip, 0, I2CF_START_COND, alen, &xaddr[4-alen]);
 648         if (rc != 0) {
 649                 if (gd->have_console)
 650                         printf("i2c_read: i2c_send failed (%d)\n", rc);
 651                 return 1;
 652         }
 653
 654         rc = i2c_receive(&state, chip, 0, I2CF_STOP_COND, len, buffer);
 655         if (rc != 0) {
 656                 if (gd->have_console)
 657                         printf("i2c_read: i2c_receive failed (%d)\n", rc);
 658                 return 1;
 659         }
 660
 661         rc = i2c_doio(&state);
 662         if (rc != 0) {
 663                 if (gd->have_console)
 664                         printf("i2c_read: i2c_doio failed (%d)\n", rc);
 665                 return 1;
 666         }
 667         return 0;
 668 }
 669
 670 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 671 {
 672         i2c_state_t state;
 673         uchar xaddr[4];
 674         int rc;
 675
 676         xaddr[0] = (addr >> 24) & 0xFF;
 677         xaddr[1] = (addr >> 16) & 0xFF;
 678         xaddr[2] = (addr >>  8) & 0xFF;
 679         xaddr[3] =  addr        & 0xFF;
 680
 681 #ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
 682         /*
 683          * EEPROM chips that implement "address overflow" are ones like
 684          * Catalyst 24WC04/08/16 which has 9/10/11 bits of address and the
 685          * extra bits end up in the "chip address" bit slots.  This makes
 686          * a 24WC08 (1Kbyte) chip look like four 256 byte chips.
 687          *
 688          * Note that we consider the length of the address field to still
 689          * be one byte because the extra address bits are hidden in the
 690          * chip address.
 691          */
 692          chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
 693 #endif
 694
 695         i2c_newio(&state);
 696
 697         rc = i2c_send(&state, chip, 0, I2CF_START_COND, alen, &xaddr[4-alen]);
 698         if (rc != 0) {
 699                 if (gd->have_console)
 700                         printf("i2c_write: first i2c_send failed (%d)\n", rc);
 701                 return 1;
 702         }
 703
 704         rc = i2c_send(&state, 0, 0, I2CF_STOP_COND, len, buffer);
 705         if (rc != 0) {
 706                 if (gd->have_console)
 707                         printf("i2c_write: second i2c_send failed (%d)\n", rc);
 708                 return 1;
 709         }
 710
 711         rc = i2c_doio(&state);
 712         if (rc != 0) {
 713                 if (gd->have_console)
 714                         printf("i2c_write: i2c_doio failed (%d)\n", rc);
 715                 return 1;
 716         }
 717         return 0;
 718 }
 719
 720 uchar
 721 i2c_reg_read(uchar i2c_addr, uchar reg)
 722 {
 723         uchar buf;
 724
 725         i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE);
 726
 727         i2c_read(i2c_addr, reg, 1, &buf, 1);
 728
 729         return (buf);
 730 }
 731
 732 void
 733 i2c_reg_write(uchar i2c_addr, uchar reg, uchar val)
 734 {
 735         i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE);
 736
 737         i2c_write(i2c_addr, reg, 1, &val, 1);
 738 }
 739
 740 #endif  /* CONFIG_HARD_I2C */