git.oblomov.eu Git - linux-2.6/blob - arch/cris/arch-v10/drivers/i2c.c

   1 /*!***************************************************************************
   2 *!
   3 *! FILE NAME  : i2c.c
   4 *!
   5 *! DESCRIPTION: implements an interface for IIC/I2C, both directly from other
   6 *!              kernel modules (i2c_writereg/readreg) and from userspace using
   7 *!              ioctl()'s
   8 *!
   9 *! Nov 30 1998  Torbjorn Eliasson  Initial version.
  10 *!              Bjorn Wesen        Elinux kernel version.
  11 *! Jan 14 2000  Johan Adolfsson    Fixed PB shadow register stuff -
  12 *!                                 don't use PB_I2C if DS1302 uses same bits,
  13 *!                                 use PB.
  14 *! $Log: i2c.c,v $
  15 *! Revision 1.13  2005/03/07 13:13:07  starvik
  16 *! Added spinlocks to protect states etc
  17 *!
  18 *! Revision 1.12  2005/01/05 06:11:22  starvik
  19 *! No need to do local_irq_disable after local_irq_save.
  20 *!
  21 *! Revision 1.11  2004/12/13 12:21:52  starvik
  22 *! Added I/O and DMA allocators from Linux 2.4
  23 *!
  24 *! Revision 1.9  2004/08/24 06:49:14  starvik
  25 *! Whitespace cleanup
  26 *!
  27 *! Revision 1.8  2004/06/08 08:48:26  starvik
  28 *! Removed unused code
  29 *!
  30 *! Revision 1.7  2004/05/28 09:26:59  starvik
  31 *! Modified I2C initialization to work in 2.6.
  32 *!
  33 *! Revision 1.6  2004/05/14 07:58:03  starvik
  34 *! Merge of changes from 2.4
  35 *!
  36 *! Revision 1.4  2002/12/11 13:13:57  starvik
  37 *! Added arch/ to v10 specific includes
  38 *! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
  39 *!
  40 *! Revision 1.3  2002/11/20 11:56:11  starvik
  41 *! Merge of Linux 2.5.48
  42 *!
  43 *! Revision 1.2  2002/11/18 13:16:06  starvik
  44 *! Linux 2.5 port of latest 2.4 drivers
  45 *!
  46 *! Revision 1.9  2002/10/31 15:32:26  starvik
  47 *! Update Port B register and shadow even when running with hardware support
  48 *!   to avoid glitches when reading bits
  49 *! Never set direction to out in i2c_inbyte
  50 *! Removed incorrect clock togling at end of i2c_inbyte
  51 *!
  52 *! Revision 1.8  2002/08/13 06:31:53  starvik
  53 *! Made SDA and SCL line configurable
  54 *! Modified i2c_inbyte to work with PCF8563
  55 *!
  56 *! Revision 1.7  2001/04/04 13:11:36  markusl
  57 *! Updated according to review remarks
  58 *!
  59 *! Revision 1.6  2001/03/19 12:43:00  markusl
  60 *! Made some symbols unstatic (used by the eeprom driver)
  61 *!
  62 *! Revision 1.5  2001/02/27 13:52:48  bjornw
  63 *! malloc.h -> slab.h
  64 *!
  65 *! Revision 1.4  2001/02/15 07:17:40  starvik
  66 *! Corrected usage if port_pb_i2c_shadow
  67 *!
  68 *! Revision 1.3  2001/01/26 17:55:13  bjornw
  69 *! * Made I2C_USES_PB_NOT_PB_I2C a CONFIG option instead of assigning it
  70 *!   magically. Config.in needs to set it for the options that need it, like
  71 *!   Dallas 1302 support. Actually, it should be default since it screws up
  72 *!   the PB bits even if you don't use I2C..
  73 *! * Include linux/config.h to get the above
  74 *!
  75 *! Revision 1.2  2001/01/18 15:49:30  bjornw
  76 *! 2.4 port of I2C including some cleanups (untested of course)
  77 *!
  78 *! Revision 1.1  2001/01/18 15:35:25  bjornw
  79 *! Verbatim copy of the Etrax i2c driver, 2.0 elinux version
  80 *!
  81 *!
  82 *! ---------------------------------------------------------------------------
  83 *!
  84 *! (C) Copyright 1999-2002 Axis Communications AB, LUND, SWEDEN
  85 *!
  86 *!***************************************************************************/
  87 /* $Id: i2c.c,v 1.13 2005/03/07 13:13:07 starvik Exp $ */
  88
  89 /****************** INCLUDE FILES SECTION ***********************************/
  90
  91 #include <linux/module.h>
  92 #include <linux/sched.h>
  93 #include <linux/slab.h>
  94 #include <linux/errno.h>
  95 #include <linux/kernel.h>
  96 #include <linux/fs.h>
  97 #include <linux/string.h>
  98 #include <linux/init.h>
  99 #include <linux/config.h>
 100
 101 #include <asm/etraxi2c.h>
 102
 103 #include <asm/system.h>
 104 #include <asm/arch/svinto.h>
 105 #include <asm/io.h>
 106 #include <asm/delay.h>
 107 #include <asm/arch/io_interface_mux.h>
 108
 109 #include "i2c.h"
 110
 111 /****************** I2C DEFINITION SECTION *************************/
 112
 113 #define D(x)
 114
 115 #define I2C_MAJOR 123  /* LOCAL/EXPERIMENTAL */
 116 static const char i2c_name[] = "i2c";
 117
 118 #define CLOCK_LOW_TIME            8
 119 #define CLOCK_HIGH_TIME           8
 120 #define START_CONDITION_HOLD_TIME 8
 121 #define STOP_CONDITION_HOLD_TIME  8
 122 #define ENABLE_OUTPUT 0x01
 123 #define ENABLE_INPUT 0x00
 124 #define I2C_CLOCK_HIGH 1
 125 #define I2C_CLOCK_LOW 0
 126 #define I2C_DATA_HIGH 1
 127 #define I2C_DATA_LOW 0
 128
 129 #ifdef CONFIG_ETRAX_I2C_USES_PB_NOT_PB_I2C
 130 /* Use PB and not PB_I2C */
 131 #ifndef CONFIG_ETRAX_I2C_DATA_PORT
 132 #define CONFIG_ETRAX_I2C_DATA_PORT 0
 133 #endif
 134 #ifndef CONFIG_ETRAX_I2C_CLK_PORT
 135 #define CONFIG_ETRAX_I2C_CLK_PORT 1
 136 #endif
 137
 138 #define SDABIT CONFIG_ETRAX_I2C_DATA_PORT
 139 #define SCLBIT CONFIG_ETRAX_I2C_CLK_PORT
 140 #define i2c_enable()
 141 #define i2c_disable()
 142
 143 /* enable or disable output-enable, to select output or input on the i2c bus */
 144
 145 #define i2c_dir_out() \
 146   REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, SDABIT, 1)
 147 #define i2c_dir_in()  \
 148   REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, SDABIT, 0)
 149
 150 /* control the i2c clock and data signals */
 151
 152 #define i2c_clk(x) \
 153   REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, SCLBIT, x)
 154 #define i2c_data(x) \
 155   REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, SDABIT, x)
 156
 157 /* read a bit from the i2c interface */
 158
 159 #define i2c_getbit() (((*R_PORT_PB_READ & (1 << SDABIT))) >> SDABIT)
 160
 161 #else
 162 /* enable or disable the i2c interface */
 163
 164 #define i2c_enable() *R_PORT_PB_I2C = (port_pb_i2c_shadow |= IO_MASK(R_PORT_PB_I2C, i2c_en))
 165 #define i2c_disable() *R_PORT_PB_I2C = (port_pb_i2c_shadow &= ~IO_MASK(R_PORT_PB_I2C, i2c_en))
 166
 167 /* enable or disable output-enable, to select output or input on the i2c bus */
 168
 169 #define i2c_dir_out() \
 170         *R_PORT_PB_I2C = (port_pb_i2c_shadow &= ~IO_MASK(R_PORT_PB_I2C, i2c_oe_)); \
 171         REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, 0, 1);
 172 #define i2c_dir_in() \
 173         *R_PORT_PB_I2C = (port_pb_i2c_shadow |= IO_MASK(R_PORT_PB_I2C, i2c_oe_)); \
 174         REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, 0, 0);
 175
 176 /* control the i2c clock and data signals */
 177
 178 #define i2c_clk(x) \
 179         *R_PORT_PB_I2C = (port_pb_i2c_shadow = (port_pb_i2c_shadow & \
 180        ~IO_MASK(R_PORT_PB_I2C, i2c_clk)) | IO_FIELD(R_PORT_PB_I2C, i2c_clk, (x))); \
 181        REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, 1, x);
 182
 183 #define i2c_data(x) \
 184         *R_PORT_PB_I2C = (port_pb_i2c_shadow = (port_pb_i2c_shadow & \
 185            ~IO_MASK(R_PORT_PB_I2C, i2c_d)) | IO_FIELD(R_PORT_PB_I2C, i2c_d, (x))); \
 186         REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, 0, x);
 187
 188 /* read a bit from the i2c interface */
 189
 190 #define i2c_getbit() (*R_PORT_PB_READ & 0x1)
 191 #endif
 192
 193 /* use the kernels delay routine */
 194
 195 #define i2c_delay(usecs) udelay(usecs)
 196
 197 static DEFINE_SPINLOCK(i2c_lock); /* Protect directions etc */
 198
 199 /****************** FUNCTION DEFINITION SECTION *************************/
 200
 201
 202 /* generate i2c start condition */
 203
 204 void
 205 i2c_start(void)
 206 {
 207         /*
 208          * SCL=1 SDA=1
 209          */
 210         i2c_dir_out();
 211         i2c_delay(CLOCK_HIGH_TIME/6);
 212         i2c_data(I2C_DATA_HIGH);
 213         i2c_clk(I2C_CLOCK_HIGH);
 214         i2c_delay(CLOCK_HIGH_TIME);
 215         /*
 216          * SCL=1 SDA=0
 217          */
 218         i2c_data(I2C_DATA_LOW);
 219         i2c_delay(START_CONDITION_HOLD_TIME);
 220         /*
 221          * SCL=0 SDA=0
 222          */
 223         i2c_clk(I2C_CLOCK_LOW);
 224         i2c_delay(CLOCK_LOW_TIME);
 225 }
 226
 227 /* generate i2c stop condition */
 228
 229 void
 230 i2c_stop(void)
 231 {
 232         i2c_dir_out();
 233
 234         /*
 235          * SCL=0 SDA=0
 236          */
 237         i2c_clk(I2C_CLOCK_LOW);
 238         i2c_data(I2C_DATA_LOW);
 239         i2c_delay(CLOCK_LOW_TIME*2);
 240         /*
 241          * SCL=1 SDA=0
 242          */
 243         i2c_clk(I2C_CLOCK_HIGH);
 244         i2c_delay(CLOCK_HIGH_TIME*2);
 245         /*
 246          * SCL=1 SDA=1
 247          */
 248         i2c_data(I2C_DATA_HIGH);
 249         i2c_delay(STOP_CONDITION_HOLD_TIME);
 250
 251         i2c_dir_in();
 252 }
 253
 254 /* write a byte to the i2c interface */
 255
 256 void
 257 i2c_outbyte(unsigned char x)
 258 {
 259         int i;
 260
 261         i2c_dir_out();
 262
 263         for (i = 0; i < 8; i++) {
 264                 if (x & 0x80) {
 265                         i2c_data(I2C_DATA_HIGH);
 266                 } else {
 267                         i2c_data(I2C_DATA_LOW);
 268                 }
 269
 270                 i2c_delay(CLOCK_LOW_TIME/2);
 271                 i2c_clk(I2C_CLOCK_HIGH);
 272                 i2c_delay(CLOCK_HIGH_TIME);
 273                 i2c_clk(I2C_CLOCK_LOW);
 274                 i2c_delay(CLOCK_LOW_TIME/2);
 275                 x <<= 1;
 276         }
 277         i2c_data(I2C_DATA_LOW);
 278         i2c_delay(CLOCK_LOW_TIME/2);
 279
 280         /*
 281          * enable input
 282          */
 283         i2c_dir_in();
 284 }
 285
 286 /* read a byte from the i2c interface */
 287
 288 unsigned char
 289 i2c_inbyte(void)
 290 {
 291         unsigned char aBitByte = 0;
 292         int i;
 293
 294         /* Switch off I2C to get bit */
 295         i2c_disable();
 296         i2c_dir_in();
 297         i2c_delay(CLOCK_HIGH_TIME/2);
 298
 299         /* Get bit */
 300         aBitByte |= i2c_getbit();
 301
 302         /* Enable I2C */
 303         i2c_enable();
 304         i2c_delay(CLOCK_LOW_TIME/2);
 305
 306         for (i = 1; i < 8; i++) {
 307                 aBitByte <<= 1;
 308                 /* Clock pulse */
 309                 i2c_clk(I2C_CLOCK_HIGH);
 310                 i2c_delay(CLOCK_HIGH_TIME);
 311                 i2c_clk(I2C_CLOCK_LOW);
 312                 i2c_delay(CLOCK_LOW_TIME);
 313
 314                 /* Switch off I2C to get bit */
 315                 i2c_disable();
 316                 i2c_dir_in();
 317                 i2c_delay(CLOCK_HIGH_TIME/2);
 318
 319                 /* Get bit */
 320                 aBitByte |= i2c_getbit();
 321
 322                 /* Enable I2C */
 323                 i2c_enable();
 324                 i2c_delay(CLOCK_LOW_TIME/2);
 325         }
 326         i2c_clk(I2C_CLOCK_HIGH);
 327         i2c_delay(CLOCK_HIGH_TIME);
 328
 329         /*
 330          * we leave the clock low, getbyte is usually followed
 331          * by sendack/nack, they assume the clock to be low
 332          */
 333         i2c_clk(I2C_CLOCK_LOW);
 334         return aBitByte;
 335 }
 336
 337 /*#---------------------------------------------------------------------------
 338 *#
 339 *# FUNCTION NAME: i2c_getack
 340 *#
 341 *# DESCRIPTION  : checks if ack was received from ic2
 342 *#
 343 *#--------------------------------------------------------------------------*/
 344
 345 int
 346 i2c_getack(void)
 347 {
 348         int ack = 1;
 349         /*
 350          * enable output
 351          */
 352         i2c_dir_out();
 353         /*
 354          * Release data bus by setting
 355          * data high
 356          */
 357         i2c_data(I2C_DATA_HIGH);
 358         /*
 359          * enable input
 360          */
 361         i2c_dir_in();
 362         i2c_delay(CLOCK_HIGH_TIME/4);
 363         /*
 364          * generate ACK clock pulse
 365          */
 366         i2c_clk(I2C_CLOCK_HIGH);
 367         /*
 368          * Use PORT PB instead of I2C
 369          * for input. (I2C not working)
 370          */
 371         i2c_clk(1);
 372         i2c_data(1);
 373         /*
 374          * switch off I2C
 375          */
 376         i2c_data(1);
 377         i2c_disable();
 378         i2c_dir_in();
 379         /*
 380          * now wait for ack
 381          */
 382         i2c_delay(CLOCK_HIGH_TIME/2);
 383         /*
 384          * check for ack
 385          */
 386         if(i2c_getbit())
 387                 ack = 0;
 388         i2c_delay(CLOCK_HIGH_TIME/2);
 389         if(!ack){
 390                 if(!i2c_getbit()) /* receiver pulld SDA low */
 391                         ack = 1;
 392                 i2c_delay(CLOCK_HIGH_TIME/2);
 393         }
 394
 395         /*
 396          * our clock is high now, make sure data is low
 397          * before we enable our output. If we keep data high
 398          * and enable output, we would generate a stop condition.
 399          */
 400         i2c_data(I2C_DATA_LOW);
 401
 402         /*
 403          * end clock pulse
 404          */
 405         i2c_enable();
 406         i2c_dir_out();
 407         i2c_clk(I2C_CLOCK_LOW);
 408         i2c_delay(CLOCK_HIGH_TIME/4);
 409         /*
 410          * enable output
 411          */
 412         i2c_dir_out();
 413         /*
 414          * remove ACK clock pulse
 415          */
 416         i2c_data(I2C_DATA_HIGH);
 417         i2c_delay(CLOCK_LOW_TIME/2);
 418         return ack;
 419 }
 420
 421 /*#---------------------------------------------------------------------------
 422 *#
 423 *# FUNCTION NAME: I2C::sendAck
 424 *#
 425 *# DESCRIPTION  : Send ACK on received data
 426 *#
 427 *#--------------------------------------------------------------------------*/
 428 void
 429 i2c_sendack(void)
 430 {
 431         /*
 432          * enable output
 433          */
 434         i2c_delay(CLOCK_LOW_TIME);
 435         i2c_dir_out();
 436         /*
 437          * set ack pulse high
 438          */
 439         i2c_data(I2C_DATA_LOW);
 440         /*
 441          * generate clock pulse
 442          */
 443         i2c_delay(CLOCK_HIGH_TIME/6);
 444         i2c_clk(I2C_CLOCK_HIGH);
 445         i2c_delay(CLOCK_HIGH_TIME);
 446         i2c_clk(I2C_CLOCK_LOW);
 447         i2c_delay(CLOCK_LOW_TIME/6);
 448         /*
 449          * reset data out
 450          */
 451         i2c_data(I2C_DATA_HIGH);
 452         i2c_delay(CLOCK_LOW_TIME);
 453
 454         i2c_dir_in();
 455 }
 456
 457 /*#---------------------------------------------------------------------------
 458 *#
 459 *# FUNCTION NAME: i2c_sendnack
 460 *#
 461 *# DESCRIPTION  : Sends NACK on received data
 462 *#
 463 *#--------------------------------------------------------------------------*/
 464 void
 465 i2c_sendnack(void)
 466 {
 467         /*
 468          * enable output
 469          */
 470         i2c_delay(CLOCK_LOW_TIME);
 471         i2c_dir_out();
 472         /*
 473          * set data high
 474          */
 475         i2c_data(I2C_DATA_HIGH);
 476         /*
 477          * generate clock pulse
 478          */
 479         i2c_delay(CLOCK_HIGH_TIME/6);
 480         i2c_clk(I2C_CLOCK_HIGH);
 481         i2c_delay(CLOCK_HIGH_TIME);
 482         i2c_clk(I2C_CLOCK_LOW);
 483         i2c_delay(CLOCK_LOW_TIME);
 484
 485         i2c_dir_in();
 486 }
 487
 488 /*#---------------------------------------------------------------------------
 489 *#
 490 *# FUNCTION NAME: i2c_writereg
 491 *#
 492 *# DESCRIPTION  : Writes a value to an I2C device
 493 *#
 494 *#--------------------------------------------------------------------------*/
 495 int
 496 i2c_writereg(unsigned char theSlave, unsigned char theReg,
 497              unsigned char theValue)
 498 {
 499         int error, cntr = 3;
 500         unsigned long flags;
 501
 502         spin_lock(&i2c_lock);
 503
 504         do {
 505                 error = 0;
 506                 /*
 507                  * we don't like to be interrupted
 508                  */
 509                 local_irq_save(flags);
 510
 511                 i2c_start();
 512                 /*
 513                  * send slave address
 514                  */
 515                 i2c_outbyte((theSlave & 0xfe));
 516                 /*
 517                  * wait for ack
 518                  */
 519                 if(!i2c_getack())
 520                         error = 1;
 521                 /*
 522                  * now select register
 523                  */
 524                 i2c_dir_out();
 525                 i2c_outbyte(theReg);
 526                 /*
 527                  * now it's time to wait for ack
 528                  */
 529                 if(!i2c_getack())
 530                         error |= 2;
 531                 /*
 532                  * send register register data
 533                  */
 534                 i2c_outbyte(theValue);
 535                 /*
 536                  * now it's time to wait for ack
 537                  */
 538                 if(!i2c_getack())
 539                         error |= 4;
 540                 /*
 541                  * end byte stream
 542                  */
 543                 i2c_stop();
 544                 /*
 545                  * enable interrupt again
 546                  */
 547                 local_irq_restore(flags);
 548
 549         } while(error && cntr--);
 550
 551         i2c_delay(CLOCK_LOW_TIME);
 552
 553         spin_unlock(&i2c_lock);
 554
 555         return -error;
 556 }
 557
 558 /*#---------------------------------------------------------------------------
 559 *#
 560 *# FUNCTION NAME: i2c_readreg
 561 *#
 562 *# DESCRIPTION  : Reads a value from the decoder registers.
 563 *#
 564 *#--------------------------------------------------------------------------*/
 565 unsigned char
 566 i2c_readreg(unsigned char theSlave, unsigned char theReg)
 567 {
 568         unsigned char b = 0;
 569         int error, cntr = 3;
 570         unsigned long flags;
 571
 572         spin_lock(&i2c_lock);
 573
 574         do {
 575                 error = 0;
 576                 /*
 577                  * we don't like to be interrupted
 578                  */
 579                 local_irq_save(flags);
 580                 /*
 581                  * generate start condition
 582                  */
 583                 i2c_start();
 584
 585                 /*
 586                  * send slave address
 587                  */
 588                 i2c_outbyte((theSlave & 0xfe));
 589                 /*
 590                  * wait for ack
 591                  */
 592                 if(!i2c_getack())
 593                         error = 1;
 594                 /*
 595                  * now select register
 596                  */
 597                 i2c_dir_out();
 598                 i2c_outbyte(theReg);
 599                 /*
 600                  * now it's time to wait for ack
 601                  */
 602                 if(!i2c_getack())
 603                         error = 1;
 604                 /*
 605                  * repeat start condition
 606                  */
 607                 i2c_delay(CLOCK_LOW_TIME);
 608                 i2c_start();
 609                 /*
 610                  * send slave address
 611                  */
 612                 i2c_outbyte(theSlave | 0x01);
 613                 /*
 614                  * wait for ack
 615                  */
 616                 if(!i2c_getack())
 617                         error = 1;
 618                 /*
 619                  * fetch register
 620                  */
 621                 b = i2c_inbyte();
 622                 /*
 623                  * last received byte needs to be nacked
 624                  * instead of acked
 625                  */
 626                 i2c_sendack();
 627                 /*
 628                  * end sequence
 629                  */
 630                 i2c_stop();
 631                 /*
 632                  * enable interrupt again
 633                  */
 634                 local_irq_restore(flags);
 635
 636         } while(error && cntr--);
 637
 638         spin_unlock(&i2c_lock);
 639
 640         return b;
 641 }
 642
 643 static int
 644 i2c_open(struct inode *inode, struct file *filp)
 645 {
 646         return 0;
 647 }
 648
 649 static int
 650 i2c_release(struct inode *inode, struct file *filp)
 651 {
 652         return 0;
 653 }
 654
 655 /* Main device API. ioctl's to write or read to/from i2c registers.
 656  */
 657
 658 static int
 659 i2c_ioctl(struct inode *inode, struct file *file,
 660           unsigned int cmd, unsigned long arg)
 661 {
 662         if(_IOC_TYPE(cmd) != ETRAXI2C_IOCTYPE) {
 663                 return -EINVAL;
 664         }
 665
 666         switch (_IOC_NR(cmd)) {
 667                 case I2C_WRITEREG:
 668                         /* write to an i2c slave */
 669                         D(printk("i2cw %d %d %d\n",
 670                                  I2C_ARGSLAVE(arg),
 671                                  I2C_ARGREG(arg),
 672                                  I2C_ARGVALUE(arg)));
 673
 674                         return i2c_writereg(I2C_ARGSLAVE(arg),
 675                                             I2C_ARGREG(arg),
 676                                             I2C_ARGVALUE(arg));
 677                 case I2C_READREG:
 678                 {
 679                         unsigned char val;
 680                         /* read from an i2c slave */
 681                         D(printk("i2cr %d %d ",
 682                                 I2C_ARGSLAVE(arg),
 683                                 I2C_ARGREG(arg)));
 684                         val = i2c_readreg(I2C_ARGSLAVE(arg), I2C_ARGREG(arg));
 685                         D(printk("= %d\n", val));
 686                         return val;
 687                 }
 688                 default:
 689                         return -EINVAL;
 690
 691         }
 692
 693         return 0;
 694 }
 695
 696 static struct file_operations i2c_fops = {
 697         .owner    = THIS_MODULE,
 698         .ioctl    = i2c_ioctl,
 699         .open     = i2c_open,
 700         .release  = i2c_release,
 701 };
 702
 703 int __init
 704 i2c_init(void)
 705 {
 706         static int res = 0;
 707         static int first = 1;
 708
 709         if (!first) {
 710                 return res;
 711         }
 712
 713         /* Setup and enable the Port B I2C interface */
 714
 715 #ifndef CONFIG_ETRAX_I2C_USES_PB_NOT_PB_I2C
 716         if ((res = cris_request_io_interface(if_i2c, "I2C"))) {
 717                 printk(KERN_CRIT "i2c_init: Failed to get IO interface\n");
 718                 return res;
 719         }
 720
 721         *R_PORT_PB_I2C = port_pb_i2c_shadow |=
 722                 IO_STATE(R_PORT_PB_I2C, i2c_en,  on) |
 723                 IO_FIELD(R_PORT_PB_I2C, i2c_d,   1)  |
 724                 IO_FIELD(R_PORT_PB_I2C, i2c_clk, 1)  |
 725                 IO_STATE(R_PORT_PB_I2C, i2c_oe_, enable);
 726
 727         port_pb_dir_shadow &= ~IO_MASK(R_PORT_PB_DIR, dir0);
 728         port_pb_dir_shadow &= ~IO_MASK(R_PORT_PB_DIR, dir1);
 729
 730         *R_PORT_PB_DIR = (port_pb_dir_shadow |=
 731                           IO_STATE(R_PORT_PB_DIR, dir0, input)  |
 732                           IO_STATE(R_PORT_PB_DIR, dir1, output));
 733 #else
 734         if ((res = cris_io_interface_allocate_pins(if_i2c,
 735                                                    'b',
 736                                                    CONFIG_ETRAX_I2C_DATA_PORT,
 737                                                    CONFIG_ETRAX_I2C_DATA_PORT))) {
 738                 printk(KERN_WARNING "i2c_init: Failed to get IO pin for I2C data port\n");
 739                 return res;
 740         } else if ((res = cris_io_interface_allocate_pins(if_i2c,
 741                                                           'b',
 742                                                           CONFIG_ETRAX_I2C_CLK_PORT,
 743                                                           CONFIG_ETRAX_I2C_CLK_PORT))) {
 744                 cris_io_interface_free_pins(if_i2c,
 745                                             'b',
 746                                             CONFIG_ETRAX_I2C_DATA_PORT,
 747                                             CONFIG_ETRAX_I2C_DATA_PORT);
 748                 printk(KERN_WARNING "i2c_init: Failed to get IO pin for I2C clk port\n");
 749         }
 750 #endif
 751
 752         return res;
 753 }
 754
 755 static int __init
 756 i2c_register(void)
 757 {
 758         int res;
 759
 760         res = i2c_init();
 761         if (res < 0)
 762                 return res;
 763         res = register_chrdev(I2C_MAJOR, i2c_name, &i2c_fops);
 764         if(res < 0) {
 765                 printk(KERN_ERR "i2c: couldn't get a major number.\n");
 766                 return res;
 767         }
 768
 769         printk(KERN_INFO "I2C driver v2.2, (c) 1999-2004 Axis Communications AB\n");
 770
 771         return 0;
 772 }
 773
 774 /* this makes sure that i2c_register is called during boot */
 775
 776 module_init(i2c_register);
 777
 778 /****************** END OF FILE i2c.c ********************************/