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 = (struct mv_i2c *)CONFIG_MV_I2C_REG;
  70
  71 /*
  72  * i2c_reset: - reset the host controller
  73  *
  74  */
  75 static void i2c_reset(void)
  76 {
  77         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
  78         writel(readl(&base->icr) | ICR_UR, &base->icr);   /* reset the unit */
  79         udelay(100);
  80         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
  81
  82         i2c_clk_enable();
  83
  84         writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
  85         writel(I2C_ICR_INIT, &base->icr); /* set control reg values */
  86         writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
  87         writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
  88         udelay(100);
  89 }
  90
  91 /*
  92  * i2c_isr_set_cleared: - wait until certain bits of the I2C status register
  93  *                        are set and cleared
  94  *
  95  * @return: 1 in case of success, 0 means timeout (no match within 10 ms).
  96  */
  97 static int i2c_isr_set_cleared(unsigned long set_mask,
  98                                unsigned long cleared_mask)
  99 {
 100         int timeout = 1000, isr;
 101
 102         do {
 103                 isr = readl(&base->isr);
 104                 udelay(10);
 105                 if (timeout-- < 0)
 106                         return 0;
 107         } while (((isr & set_mask) != set_mask)
 108                 || ((isr & cleared_mask) != 0));
 109
 110         return 1;
 111 }
 112
 113 /*
 114  * i2c_transfer: - Transfer one byte over the i2c bus
 115  *
 116  * This function can tranfer a byte over the i2c bus in both directions.
 117  * It is used by the public API functions.
 118  *
 119  * @return:  0: transfer successful
 120  *          -1: message is empty
 121  *          -2: transmit timeout
 122  *          -3: ACK missing
 123  *          -4: receive timeout
 124  *          -5: illegal parameters
 125  *          -6: bus is busy and couldn't be aquired
 126  */
 127 int i2c_transfer(struct i2c_msg *msg)
 128 {
 129         int ret;
 130
 131         if (!msg)
 132                 goto transfer_error_msg_empty;
 133
 134         switch (msg->direction) {
 135         case I2C_WRITE:
 136                 /* check if bus is not busy */
 137                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 138                         goto transfer_error_bus_busy;
 139
 140                 /* start transmission */
 141                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 142                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 143                 writel(msg->data, &base->idbr);
 144                 if (msg->condition == I2C_COND_START)
 145                         writel(readl(&base->icr) | ICR_START, &base->icr);
 146                 if (msg->condition == I2C_COND_STOP)
 147                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 148                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 149                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 150                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 151                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 152                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 153                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 154
 155                 /* transmit register empty? */
 156                 if (!i2c_isr_set_cleared(ISR_ITE, 0))
 157                         goto transfer_error_transmit_timeout;
 158
 159                 /* clear 'transmit empty' state */
 160                 writel(readl(&base->isr) | ISR_ITE, &base->isr);
 161
 162                 /* wait for ACK from slave */
 163                 if (msg->acknack == I2C_ACKNAK_WAITACK)
 164                         if (!i2c_isr_set_cleared(0, ISR_ACKNAK))
 165                                 goto transfer_error_ack_missing;
 166                 break;
 167
 168         case I2C_READ:
 169
 170                 /* check if bus is not busy */
 171                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 172                         goto transfer_error_bus_busy;
 173
 174                 /* start receive */
 175                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 176                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 177                 if (msg->condition == I2C_COND_START)
 178                         writel(readl(&base->icr) | ICR_START, &base->icr);
 179                 if (msg->condition == I2C_COND_STOP)
 180                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 181                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 182                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 183                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 184                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 185                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 186                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 187
 188                 /* receive register full? */
 189                 if (!i2c_isr_set_cleared(ISR_IRF, 0))
 190                         goto transfer_error_receive_timeout;
 191
 192                 msg->data = readl(&base->idbr);
 193
 194                 /* clear 'receive empty' state */
 195                 writel(readl(&base->isr) | ISR_IRF, &base->isr);
 196                 break;
 197         default:
 198                 goto transfer_error_illegal_param;
 199         }
 200
 201         return 0;
 202
 203 transfer_error_msg_empty:
 204                 PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
 205                 ret = -1; goto i2c_transfer_finish;
 206
 207 transfer_error_transmit_timeout:
 208                 PRINTD(("i2c_transfer: error: transmit timeout\n"));
 209                 ret = -2; goto i2c_transfer_finish;
 210
 211 transfer_error_ack_missing:
 212                 PRINTD(("i2c_transfer: error: ACK missing\n"));
 213                 ret = -3; goto i2c_transfer_finish;
 214
 215 transfer_error_receive_timeout:
 216                 PRINTD(("i2c_transfer: error: receive timeout\n"));
 217                 ret = -4; goto i2c_transfer_finish;
 218
 219 transfer_error_illegal_param:
 220                 PRINTD(("i2c_transfer: error: illegal parameters\n"));
 221                 ret = -5; goto i2c_transfer_finish;
 222
 223 transfer_error_bus_busy:
 224                 PRINTD(("i2c_transfer: error: bus is busy\n"));
 225                 ret = -6; goto i2c_transfer_finish;
 226
 227 i2c_transfer_finish:
 228                 PRINTD(("i2c_transfer: ISR: 0x%04x\n", ISR));
 229                 i2c_reset();
 230                 return ret;
 231 }
 232
 233 /* ------------------------------------------------------------------------ */
 234 /* API Functions                                                            */
 235 /* ------------------------------------------------------------------------ */
 236 void i2c_init(int speed, int slaveaddr)
 237 {
 238 #ifdef CONFIG_SYS_I2C_INIT_BOARD
 239         u32 icr;
 240         /*
 241          * call board specific i2c bus reset routine before accessing the
 242          * environment, which might be in a chip on that bus. For details
 243          * about this problem see doc/I2C_Edge_Conditions.
 244          *
 245          * disable I2C controller first, otherwhise it thinks we want to
 246          * talk to the slave port...
 247          */
 248         icr = readl(&base->icr);
 249         writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
 250
 251         i2c_init_board();
 252
 253         writel(icr, &base->icr);
 254 #endif
 255 }
 256
 257 /*
 258  * i2c_probe: - Test if a chip answers for a given i2c address
 259  *
 260  * @chip:       address of the chip which is searched for
 261  * @return:     0 if a chip was found, -1 otherwhise
 262  */
 263 int i2c_probe(uchar chip)
 264 {
 265         struct i2c_msg msg;
 266
 267         i2c_reset();
 268
 269         msg.condition = I2C_COND_START;
 270         msg.acknack   = I2C_ACKNAK_WAITACK;
 271         msg.direction = I2C_WRITE;
 272         msg.data      = (chip << 1) + 1;
 273         if (i2c_transfer(&msg))
 274                 return -1;
 275
 276         msg.condition = I2C_COND_STOP;
 277         msg.acknack   = I2C_ACKNAK_SENDNAK;
 278         msg.direction = I2C_READ;
 279         msg.data      = 0x00;
 280         if (i2c_transfer(&msg))
 281                 return -1;
 282
 283         return 0;
 284 }
 285
 286 /*
 287  * i2c_read: - Read multiple bytes from an i2c device
 288  *
 289  * The higher level routines take into account that this function is only
 290  * called with len < page length of the device (see configuration file)
 291  *
 292  * @chip:       address of the chip which is to be read
 293  * @addr:       i2c data address within the chip
 294  * @alen:       length of the i2c data address (1..2 bytes)
 295  * @buffer:     where to write the data
 296  * @len:        how much byte do we want to read
 297  * @return:     0 in case of success
 298  */
 299 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 300 {
 301         struct i2c_msg msg;
 302         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 303
 304         PRINTD(("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 305                 "len=0x%02x)\n", chip, addr, alen, len));
 306
 307         i2c_reset();
 308
 309         /* dummy chip address write */
 310         PRINTD(("i2c_read: dummy chip address write\n"));
 311         msg.condition = I2C_COND_START;
 312         msg.acknack   = I2C_ACKNAK_WAITACK;
 313         msg.direction = I2C_WRITE;
 314         msg.data = (chip << 1);
 315         msg.data &= 0xFE;
 316         if (i2c_transfer(&msg))
 317                 return -1;
 318
 319         /*
 320          * send memory address bytes;
 321          * alen defines how much bytes we have to send.
 322          */
 323         /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
 324         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 325         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 326         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 327
 328         while (--alen >= 0) {
 329                 PRINTD(("i2c_read: send memory word address byte %1d\n", alen));
 330                 msg.condition = I2C_COND_NORMAL;
 331                 msg.acknack   = I2C_ACKNAK_WAITACK;
 332                 msg.direction = I2C_WRITE;
 333                 msg.data      = addr_bytes[alen];
 334                 if (i2c_transfer(&msg))
 335                         return -1;
 336         }
 337
 338         /* start read sequence */
 339         PRINTD(("i2c_read: start read sequence\n"));
 340         msg.condition = I2C_COND_START;
 341         msg.acknack   = I2C_ACKNAK_WAITACK;
 342         msg.direction = I2C_WRITE;
 343         msg.data      = (chip << 1);
 344         msg.data     |= 0x01;
 345         if (i2c_transfer(&msg))
 346                 return -1;
 347
 348         /* read bytes; send NACK at last byte */
 349         while (len--) {
 350                 if (len == 0) {
 351                         msg.condition = I2C_COND_STOP;
 352                         msg.acknack   = I2C_ACKNAK_SENDNAK;
 353                 } else {
 354                         msg.condition = I2C_COND_NORMAL;
 355                         msg.acknack   = I2C_ACKNAK_SENDACK;
 356                 }
 357
 358                 msg.direction = I2C_READ;
 359                 msg.data      = 0x00;
 360                 if (i2c_transfer(&msg))
 361                         return -1;
 362
 363                 *buffer = msg.data;
 364                 PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n",
 365                         (unsigned int)buffer, *buffer));
 366                 buffer++;
 367         }
 368
 369         i2c_reset();
 370
 371         return 0;
 372 }
 373
 374 /*
 375  * i2c_write: -  Write multiple bytes to an i2c device
 376  *
 377  * The higher level routines take into account that this function is only
 378  * called with len < page length of the device (see configuration file)
 379  *
 380  * @chip:       address of the chip which is to be written
 381  * @addr:       i2c data address within the chip
 382  * @alen:       length of the i2c data address (1..2 bytes)
 383  * @buffer:     where to find the data to be written
 384  * @len:        how much byte do we want to read
 385  * @return:     0 in case of success
 386  */
 387 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 388 {
 389         struct i2c_msg msg;
 390         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 391
 392         PRINTD(("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 393                 "len=0x%02x)\n", chip, addr, alen, len));
 394
 395         i2c_reset();
 396
 397         /* chip address write */
 398         PRINTD(("i2c_write: chip address write\n"));
 399         msg.condition = I2C_COND_START;
 400         msg.acknack   = I2C_ACKNAK_WAITACK;
 401         msg.direction = I2C_WRITE;
 402         msg.data = (chip << 1);
 403         msg.data &= 0xFE;
 404         if (i2c_transfer(&msg))
 405                 return -1;
 406
 407         /*
 408          * send memory address bytes;
 409          * alen defines how much bytes we have to send.
 410          */
 411         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 412         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 413         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 414
 415         while (--alen >= 0) {
 416                 PRINTD(("i2c_write: send memory word address\n"));
 417                 msg.condition = I2C_COND_NORMAL;
 418                 msg.acknack   = I2C_ACKNAK_WAITACK;
 419                 msg.direction = I2C_WRITE;
 420                 msg.data      = addr_bytes[alen];
 421                 if (i2c_transfer(&msg))
 422                         return -1;
 423         }
 424
 425         /* write bytes; send NACK at last byte */
 426         while (len--) {
 427                 PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n",
 428                         (unsigned int)buffer, *buffer));
 429
 430                 if (len == 0)
 431                         msg.condition = I2C_COND_STOP;
 432                 else
 433                         msg.condition = I2C_COND_NORMAL;
 434
 435                 msg.acknack   = I2C_ACKNAK_WAITACK;
 436                 msg.direction = I2C_WRITE;
 437                 msg.data      = *(buffer++);
 438
 439                 if (i2c_transfer(&msg))
 440                         return -1;
 441         }
 442
 443         i2c_reset();
 444
 445         return 0;
 446 }
 447 #endif  /* CONFIG_HARD_I2C */