drivers/i2c/mv_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  * (C) Copyright 2003 Pengutronix e.K.
   9  * Robert Schwebel <r.schwebel@pengutronix.de>
  10  *
  11  * (C) Copyright 2011 Marvell Inc.
  12  * Lei Wen <leiwen@marvell.com>
  13  *
  14  * See file CREDITS for list of people who contributed to this
  15  * project.
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License as
  19  * published by the Free Software Foundation; either version 2 of
  20  * the License, or (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  30  * MA 02111-1307 USA
  31  *
  32  * Back ported to the 8xx platform (from the 8260 platform) by
  33  * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
  34  */
  35
  36 #include <common.h>
  37 #include <asm/io.h>
  38
  39 #ifdef CONFIG_HARD_I2C
  40 #include <i2c.h>
  41 #include "mv_i2c.h"
  42
  43 #ifdef DEBUG_I2C
  44 #define PRINTD(x) printf x
  45 #else
  46 #define PRINTD(x)
  47 #endif
  48
  49 /* All transfers are described by this data structure */
  50 struct i2c_msg {
  51         u8 condition;
  52         u8 acknack;
  53         u8 direction;
  54         u8 data;
  55 };
  56
  57 struct mv_i2c {
  58         u32 ibmr;
  59         u32 pad0;
  60         u32 idbr;
  61         u32 pad1;
  62         u32 icr;
  63         u32 pad2;
  64         u32 isr;
  65         u32 pad3;
  66         u32 isar;
  67 };
  68
  69 static struct mv_i2c *base;
  70 static void i2c_board_init(struct mv_i2c *base)
  71 {
  72 #ifdef CONFIG_SYS_I2C_INIT_BOARD
  73         u32 icr;
  74         /*
  75          * call board specific i2c bus reset routine before accessing the
  76          * environment, which might be in a chip on that bus. For details
  77          * about this problem see doc/I2C_Edge_Conditions.
  78          *
  79          * disable I2C controller first, otherwhise it thinks we want to
  80          * talk to the slave port...
  81          */
  82         icr = readl(&base->icr);
  83         writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
  84
  85         i2c_init_board();
  86
  87         writel(icr, &base->icr);
  88 #endif
  89 }
  90
  91 #ifdef CONFIG_I2C_MULTI_BUS
  92 static u32 i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG;
  93 static unsigned int bus_initialized[CONFIG_MV_I2C_NUM];
  94 static unsigned int current_bus;
  95
  96 int i2c_set_bus_num(unsigned int bus)
  97 {
  98         if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) {
  99                 printf("Bad bus: %d\n", bus);
 100                 return -1;
 101         }
 102
 103         base = (struct mv_i2c *)i2c_regs[bus];
 104         current_bus = bus;
 105
 106         if (!bus_initialized[current_bus]) {
 107                 i2c_board_init(base);
 108                 bus_initialized[current_bus] = 1;
 109         }
 110
 111         return 0;
 112 }
 113
 114 unsigned int i2c_get_bus_num(void)
 115 {
 116         return current_bus;
 117 }
 118 #endif
 119
 120 /*
 121  * i2c_reset: - reset the host controller
 122  *
 123  */
 124 static void i2c_reset(void)
 125 {
 126         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
 127         writel(readl(&base->icr) | ICR_UR, &base->icr);   /* reset the unit */
 128         udelay(100);
 129         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
 130
 131         i2c_clk_enable();
 132
 133         writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
 134         writel(I2C_ICR_INIT, &base->icr); /* set control reg values */
 135         writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
 136         writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
 137         udelay(100);
 138 }
 139
 140 /*
 141  * i2c_isr_set_cleared: - wait until certain bits of the I2C status register
 142  *                        are set and cleared
 143  *
 144  * @return: 1 in case of success, 0 means timeout (no match within 10 ms).
 145  */
 146 static int i2c_isr_set_cleared(unsigned long set_mask,
 147                                unsigned long cleared_mask)
 148 {
 149         int timeout = 1000, isr;
 150
 151         do {
 152                 isr = readl(&base->isr);
 153                 udelay(10);
 154                 if (timeout-- < 0)
 155                         return 0;
 156         } while (((isr & set_mask) != set_mask)
 157                 || ((isr & cleared_mask) != 0));
 158
 159         return 1;
 160 }
 161
 162 /*
 163  * i2c_transfer: - Transfer one byte over the i2c bus
 164  *
 165  * This function can tranfer a byte over the i2c bus in both directions.
 166  * It is used by the public API functions.
 167  *
 168  * @return:  0: transfer successful
 169  *          -1: message is empty
 170  *          -2: transmit timeout
 171  *          -3: ACK missing
 172  *          -4: receive timeout
 173  *          -5: illegal parameters
 174  *          -6: bus is busy and couldn't be aquired
 175  */
 176 int i2c_transfer(struct i2c_msg *msg)
 177 {
 178         int ret;
 179
 180         if (!msg)
 181                 goto transfer_error_msg_empty;
 182
 183         switch (msg->direction) {
 184         case I2C_WRITE:
 185                 /* check if bus is not busy */
 186                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 187                         goto transfer_error_bus_busy;
 188
 189                 /* start transmission */
 190                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 191                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 192                 writel(msg->data, &base->idbr);
 193                 if (msg->condition == I2C_COND_START)
 194                         writel(readl(&base->icr) | ICR_START, &base->icr);
 195                 if (msg->condition == I2C_COND_STOP)
 196                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 197                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 198                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 199                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 200                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 201                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 202                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 203
 204                 /* transmit register empty? */
 205                 if (!i2c_isr_set_cleared(ISR_ITE, 0))
 206                         goto transfer_error_transmit_timeout;
 207
 208                 /* clear 'transmit empty' state */
 209                 writel(readl(&base->isr) | ISR_ITE, &base->isr);
 210
 211                 /* wait for ACK from slave */
 212                 if (msg->acknack == I2C_ACKNAK_WAITACK)
 213                         if (!i2c_isr_set_cleared(0, ISR_ACKNAK))
 214                                 goto transfer_error_ack_missing;
 215                 break;
 216
 217         case I2C_READ:
 218
 219                 /* check if bus is not busy */
 220                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 221                         goto transfer_error_bus_busy;
 222
 223                 /* start receive */
 224                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 225                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 226                 if (msg->condition == I2C_COND_START)
 227                         writel(readl(&base->icr) | ICR_START, &base->icr);
 228                 if (msg->condition == I2C_COND_STOP)
 229                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 230                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 231                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 232                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 233                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 234                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 235                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 236
 237                 /* receive register full? */
 238                 if (!i2c_isr_set_cleared(ISR_IRF, 0))
 239                         goto transfer_error_receive_timeout;
 240
 241                 msg->data = readl(&base->idbr);
 242
 243                 /* clear 'receive empty' state */
 244                 writel(readl(&base->isr) | ISR_IRF, &base->isr);
 245                 break;
 246         default:
 247                 goto transfer_error_illegal_param;
 248         }
 249
 250         return 0;
 251
 252 transfer_error_msg_empty:
 253                 PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
 254                 ret = -1; goto i2c_transfer_finish;
 255
 256 transfer_error_transmit_timeout:
 257                 PRINTD(("i2c_transfer: error: transmit timeout\n"));
 258                 ret = -2; goto i2c_transfer_finish;
 259
 260 transfer_error_ack_missing:
 261                 PRINTD(("i2c_transfer: error: ACK missing\n"));
 262                 ret = -3; goto i2c_transfer_finish;
 263
 264 transfer_error_receive_timeout:
 265                 PRINTD(("i2c_transfer: error: receive timeout\n"));
 266                 ret = -4; goto i2c_transfer_finish;
 267
 268 transfer_error_illegal_param:
 269                 PRINTD(("i2c_transfer: error: illegal parameters\n"));
 270                 ret = -5; goto i2c_transfer_finish;
 271
 272 transfer_error_bus_busy:
 273                 PRINTD(("i2c_transfer: error: bus is busy\n"));
 274                 ret = -6; goto i2c_transfer_finish;
 275
 276 i2c_transfer_finish:
 277                 PRINTD(("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr)));
 278                 i2c_reset();
 279                 return ret;
 280 }
 281
 282 /* ------------------------------------------------------------------------ */
 283 /* API Functions                                                            */
 284 /* ------------------------------------------------------------------------ */
 285 void i2c_init(int speed, int slaveaddr)
 286 {
 287 #ifdef CONFIG_I2C_MULTI_BUS
 288         current_bus = 0;
 289         base = (struct mv_i2c *)i2c_regs[current_bus];
 290 #else
 291         base = (struct mv_i2c *)CONFIG_MV_I2C_REG;
 292 #endif
 293
 294         i2c_board_init(base);
 295 }
 296
 297 /*
 298  * i2c_probe: - Test if a chip answers for a given i2c address
 299  *
 300  * @chip:       address of the chip which is searched for
 301  * @return:     0 if a chip was found, -1 otherwhise
 302  */
 303 int i2c_probe(uchar chip)
 304 {
 305         struct i2c_msg msg;
 306
 307         i2c_reset();
 308
 309         msg.condition = I2C_COND_START;
 310         msg.acknack   = I2C_ACKNAK_WAITACK;
 311         msg.direction = I2C_WRITE;
 312         msg.data      = (chip << 1) + 1;
 313         if (i2c_transfer(&msg))
 314                 return -1;
 315
 316         msg.condition = I2C_COND_STOP;
 317         msg.acknack   = I2C_ACKNAK_SENDNAK;
 318         msg.direction = I2C_READ;
 319         msg.data      = 0x00;
 320         if (i2c_transfer(&msg))
 321                 return -1;
 322
 323         return 0;
 324 }
 325
 326 /*
 327  * i2c_read: - Read multiple bytes from an i2c device
 328  *
 329  * The higher level routines take into account that this function is only
 330  * called with len < page length of the device (see configuration file)
 331  *
 332  * @chip:       address of the chip which is to be read
 333  * @addr:       i2c data address within the chip
 334  * @alen:       length of the i2c data address (1..2 bytes)
 335  * @buffer:     where to write the data
 336  * @len:        how much byte do we want to read
 337  * @return:     0 in case of success
 338  */
 339 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 340 {
 341         struct i2c_msg msg;
 342         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 343
 344         PRINTD(("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 345                 "len=0x%02x)\n", chip, addr, alen, len));
 346
 347         i2c_reset();
 348
 349         /* dummy chip address write */
 350         PRINTD(("i2c_read: dummy chip address write\n"));
 351         msg.condition = I2C_COND_START;
 352         msg.acknack   = I2C_ACKNAK_WAITACK;
 353         msg.direction = I2C_WRITE;
 354         msg.data = (chip << 1);
 355         msg.data &= 0xFE;
 356         if (i2c_transfer(&msg))
 357                 return -1;
 358
 359         /*
 360          * send memory address bytes;
 361          * alen defines how much bytes we have to send.
 362          */
 363         /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
 364         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 365         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 366         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 367
 368         while (--alen >= 0) {
 369                 PRINTD(("i2c_read: send memory word address byte %1d\n", alen));
 370                 msg.condition = I2C_COND_NORMAL;
 371                 msg.acknack   = I2C_ACKNAK_WAITACK;
 372                 msg.direction = I2C_WRITE;
 373                 msg.data      = addr_bytes[alen];
 374                 if (i2c_transfer(&msg))
 375                         return -1;
 376         }
 377
 378         /* start read sequence */
 379         PRINTD(("i2c_read: start read sequence\n"));
 380         msg.condition = I2C_COND_START;
 381         msg.acknack   = I2C_ACKNAK_WAITACK;
 382         msg.direction = I2C_WRITE;
 383         msg.data      = (chip << 1);
 384         msg.data     |= 0x01;
 385         if (i2c_transfer(&msg))
 386                 return -1;
 387
 388         /* read bytes; send NACK at last byte */
 389         while (len--) {
 390                 if (len == 0) {
 391                         msg.condition = I2C_COND_STOP;
 392                         msg.acknack   = I2C_ACKNAK_SENDNAK;
 393                 } else {
 394                         msg.condition = I2C_COND_NORMAL;
 395                         msg.acknack   = I2C_ACKNAK_SENDACK;
 396                 }
 397
 398                 msg.direction = I2C_READ;
 399                 msg.data      = 0x00;
 400                 if (i2c_transfer(&msg))
 401                         return -1;
 402
 403                 *buffer = msg.data;
 404                 PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n",
 405                         (unsigned int)buffer, *buffer));
 406                 buffer++;
 407         }
 408
 409         i2c_reset();
 410
 411         return 0;
 412 }
 413
 414 /*
 415  * i2c_write: -  Write multiple bytes to an i2c device
 416  *
 417  * The higher level routines take into account that this function is only
 418  * called with len < page length of the device (see configuration file)
 419  *
 420  * @chip:       address of the chip which is to be written
 421  * @addr:       i2c data address within the chip
 422  * @alen:       length of the i2c data address (1..2 bytes)
 423  * @buffer:     where to find the data to be written
 424  * @len:        how much byte do we want to read
 425  * @return:     0 in case of success
 426  */
 427 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 428 {
 429         struct i2c_msg msg;
 430         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 431
 432         PRINTD(("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 433                 "len=0x%02x)\n", chip, addr, alen, len));
 434
 435         i2c_reset();
 436
 437         /* chip address write */
 438         PRINTD(("i2c_write: chip address write\n"));
 439         msg.condition = I2C_COND_START;
 440         msg.acknack   = I2C_ACKNAK_WAITACK;
 441         msg.direction = I2C_WRITE;
 442         msg.data = (chip << 1);
 443         msg.data &= 0xFE;
 444         if (i2c_transfer(&msg))
 445                 return -1;
 446
 447         /*
 448          * send memory address bytes;
 449          * alen defines how much bytes we have to send.
 450          */
 451         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 452         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 453         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 454
 455         while (--alen >= 0) {
 456                 PRINTD(("i2c_write: send memory word address\n"));
 457                 msg.condition = I2C_COND_NORMAL;
 458                 msg.acknack   = I2C_ACKNAK_WAITACK;
 459                 msg.direction = I2C_WRITE;
 460                 msg.data      = addr_bytes[alen];
 461                 if (i2c_transfer(&msg))
 462                         return -1;
 463         }
 464
 465         /* write bytes; send NACK at last byte */
 466         while (len--) {
 467                 PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n",
 468                         (unsigned int)buffer, *buffer));
 469
 470                 if (len == 0)
 471                         msg.condition = I2C_COND_STOP;
 472                 else
 473                         msg.condition = I2C_COND_NORMAL;
 474
 475                 msg.acknack   = I2C_ACKNAK_WAITACK;
 476                 msg.direction = I2C_WRITE;
 477                 msg.data      = *(buffer++);
 478
 479                 if (i2c_transfer(&msg))
 480                         return -1;
 481         }
 482
 483         i2c_reset();
 484
 485         return 0;
 486 }
 487 #endif  /* CONFIG_HARD_I2C */