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  * SPDX-License-Identifier:     GPL-2.0+
  15  *
  16  * Back ported to the 8xx platform (from the 8260 platform) by
  17  * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
  18  */
  19
  20 #include <common.h>
  21 #include <asm/io.h>
  22
  23 #ifdef CONFIG_HARD_I2C
  24 #include <i2c.h>
  25 #include "mv_i2c.h"
  26
  27 #ifdef DEBUG_I2C
  28 #define PRINTD(x) printf x
  29 #else
  30 #define PRINTD(x)
  31 #endif
  32
  33 /* All transfers are described by this data structure */
  34 struct i2c_msg {
  35         u8 condition;
  36         u8 acknack;
  37         u8 direction;
  38         u8 data;
  39 };
  40
  41 struct mv_i2c {
  42         u32 ibmr;
  43         u32 pad0;
  44         u32 idbr;
  45         u32 pad1;
  46         u32 icr;
  47         u32 pad2;
  48         u32 isr;
  49         u32 pad3;
  50         u32 isar;
  51 };
  52
  53 static struct mv_i2c *base;
  54 static void i2c_board_init(struct mv_i2c *base)
  55 {
  56 #ifdef CONFIG_SYS_I2C_INIT_BOARD
  57         u32 icr;
  58         /*
  59          * call board specific i2c bus reset routine before accessing the
  60          * environment, which might be in a chip on that bus. For details
  61          * about this problem see doc/I2C_Edge_Conditions.
  62          *
  63          * disable I2C controller first, otherwhise it thinks we want to
  64          * talk to the slave port...
  65          */
  66         icr = readl(&base->icr);
  67         writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
  68
  69         i2c_init_board();
  70
  71         writel(icr, &base->icr);
  72 #endif
  73 }
  74
  75 #ifdef CONFIG_I2C_MULTI_BUS
  76 static u32 i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG;
  77 static unsigned int bus_initialized[CONFIG_MV_I2C_NUM];
  78 static unsigned int current_bus;
  79
  80 int i2c_set_bus_num(unsigned int bus)
  81 {
  82         if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) {
  83                 printf("Bad bus: %d\n", bus);
  84                 return -1;
  85         }
  86
  87         base = (struct mv_i2c *)i2c_regs[bus];
  88         current_bus = bus;
  89
  90         if (!bus_initialized[current_bus]) {
  91                 i2c_board_init(base);
  92                 bus_initialized[current_bus] = 1;
  93         }
  94
  95         return 0;
  96 }
  97
  98 unsigned int i2c_get_bus_num(void)
  99 {
 100         return current_bus;
 101 }
 102 #endif
 103
 104 /*
 105  * i2c_reset: - reset the host controller
 106  *
 107  */
 108 static void i2c_reset(void)
 109 {
 110         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
 111         writel(readl(&base->icr) | ICR_UR, &base->icr);   /* reset the unit */
 112         udelay(100);
 113         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
 114
 115         i2c_clk_enable();
 116
 117         writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
 118         writel(I2C_ICR_INIT, &base->icr); /* set control reg values */
 119         writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
 120         writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
 121         udelay(100);
 122 }
 123
 124 /*
 125  * i2c_isr_set_cleared: - wait until certain bits of the I2C status register
 126  *                        are set and cleared
 127  *
 128  * @return: 1 in case of success, 0 means timeout (no match within 10 ms).
 129  */
 130 static int i2c_isr_set_cleared(unsigned long set_mask,
 131                                unsigned long cleared_mask)
 132 {
 133         int timeout = 1000, isr;
 134
 135         do {
 136                 isr = readl(&base->isr);
 137                 udelay(10);
 138                 if (timeout-- < 0)
 139                         return 0;
 140         } while (((isr & set_mask) != set_mask)
 141                 || ((isr & cleared_mask) != 0));
 142
 143         return 1;
 144 }
 145
 146 /*
 147  * i2c_transfer: - Transfer one byte over the i2c bus
 148  *
 149  * This function can tranfer a byte over the i2c bus in both directions.
 150  * It is used by the public API functions.
 151  *
 152  * @return:  0: transfer successful
 153  *          -1: message is empty
 154  *          -2: transmit timeout
 155  *          -3: ACK missing
 156  *          -4: receive timeout
 157  *          -5: illegal parameters
 158  *          -6: bus is busy and couldn't be aquired
 159  */
 160 int i2c_transfer(struct i2c_msg *msg)
 161 {
 162         int ret;
 163
 164         if (!msg)
 165                 goto transfer_error_msg_empty;
 166
 167         switch (msg->direction) {
 168         case I2C_WRITE:
 169                 /* check if bus is not busy */
 170                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 171                         goto transfer_error_bus_busy;
 172
 173                 /* start transmission */
 174                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 175                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 176                 writel(msg->data, &base->idbr);
 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                 /* transmit register empty? */
 189                 if (!i2c_isr_set_cleared(ISR_ITE, 0))
 190                         goto transfer_error_transmit_timeout;
 191
 192                 /* clear 'transmit empty' state */
 193                 writel(readl(&base->isr) | ISR_ITE, &base->isr);
 194
 195                 /* wait for ACK from slave */
 196                 if (msg->acknack == I2C_ACKNAK_WAITACK)
 197                         if (!i2c_isr_set_cleared(0, ISR_ACKNAK))
 198                                 goto transfer_error_ack_missing;
 199                 break;
 200
 201         case I2C_READ:
 202
 203                 /* check if bus is not busy */
 204                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 205                         goto transfer_error_bus_busy;
 206
 207                 /* start receive */
 208                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 209                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 210                 if (msg->condition == I2C_COND_START)
 211                         writel(readl(&base->icr) | ICR_START, &base->icr);
 212                 if (msg->condition == I2C_COND_STOP)
 213                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 214                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 215                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 216                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 217                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 218                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 219                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 220
 221                 /* receive register full? */
 222                 if (!i2c_isr_set_cleared(ISR_IRF, 0))
 223                         goto transfer_error_receive_timeout;
 224
 225                 msg->data = readl(&base->idbr);
 226
 227                 /* clear 'receive empty' state */
 228                 writel(readl(&base->isr) | ISR_IRF, &base->isr);
 229                 break;
 230         default:
 231                 goto transfer_error_illegal_param;
 232         }
 233
 234         return 0;
 235
 236 transfer_error_msg_empty:
 237                 PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
 238                 ret = -1; goto i2c_transfer_finish;
 239
 240 transfer_error_transmit_timeout:
 241                 PRINTD(("i2c_transfer: error: transmit timeout\n"));
 242                 ret = -2; goto i2c_transfer_finish;
 243
 244 transfer_error_ack_missing:
 245                 PRINTD(("i2c_transfer: error: ACK missing\n"));
 246                 ret = -3; goto i2c_transfer_finish;
 247
 248 transfer_error_receive_timeout:
 249                 PRINTD(("i2c_transfer: error: receive timeout\n"));
 250                 ret = -4; goto i2c_transfer_finish;
 251
 252 transfer_error_illegal_param:
 253                 PRINTD(("i2c_transfer: error: illegal parameters\n"));
 254                 ret = -5; goto i2c_transfer_finish;
 255
 256 transfer_error_bus_busy:
 257                 PRINTD(("i2c_transfer: error: bus is busy\n"));
 258                 ret = -6; goto i2c_transfer_finish;
 259
 260 i2c_transfer_finish:
 261                 PRINTD(("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr)));
 262                 i2c_reset();
 263                 return ret;
 264 }
 265
 266 /* ------------------------------------------------------------------------ */
 267 /* API Functions                                                            */
 268 /* ------------------------------------------------------------------------ */
 269 void i2c_init(int speed, int slaveaddr)
 270 {
 271 #ifdef CONFIG_I2C_MULTI_BUS
 272         current_bus = 0;
 273         base = (struct mv_i2c *)i2c_regs[current_bus];
 274 #else
 275         base = (struct mv_i2c *)CONFIG_MV_I2C_REG;
 276 #endif
 277
 278         i2c_board_init(base);
 279 }
 280
 281 /*
 282  * i2c_probe: - Test if a chip answers for a given i2c address
 283  *
 284  * @chip:       address of the chip which is searched for
 285  * @return:     0 if a chip was found, -1 otherwhise
 286  */
 287 int i2c_probe(uchar chip)
 288 {
 289         struct i2c_msg msg;
 290
 291         i2c_reset();
 292
 293         msg.condition = I2C_COND_START;
 294         msg.acknack   = I2C_ACKNAK_WAITACK;
 295         msg.direction = I2C_WRITE;
 296         msg.data      = (chip << 1) + 1;
 297         if (i2c_transfer(&msg))
 298                 return -1;
 299
 300         msg.condition = I2C_COND_STOP;
 301         msg.acknack   = I2C_ACKNAK_SENDNAK;
 302         msg.direction = I2C_READ;
 303         msg.data      = 0x00;
 304         if (i2c_transfer(&msg))
 305                 return -1;
 306
 307         return 0;
 308 }
 309
 310 /*
 311  * i2c_read: - Read multiple bytes from an i2c device
 312  *
 313  * The higher level routines take into account that this function is only
 314  * called with len < page length of the device (see configuration file)
 315  *
 316  * @chip:       address of the chip which is to be read
 317  * @addr:       i2c data address within the chip
 318  * @alen:       length of the i2c data address (1..2 bytes)
 319  * @buffer:     where to write the data
 320  * @len:        how much byte do we want to read
 321  * @return:     0 in case of success
 322  */
 323 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 324 {
 325         struct i2c_msg msg;
 326         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 327
 328         PRINTD(("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 329                 "len=0x%02x)\n", chip, addr, alen, len));
 330
 331         i2c_reset();
 332
 333         /* dummy chip address write */
 334         PRINTD(("i2c_read: dummy chip address write\n"));
 335         msg.condition = I2C_COND_START;
 336         msg.acknack   = I2C_ACKNAK_WAITACK;
 337         msg.direction = I2C_WRITE;
 338         msg.data = (chip << 1);
 339         msg.data &= 0xFE;
 340         if (i2c_transfer(&msg))
 341                 return -1;
 342
 343         /*
 344          * send memory address bytes;
 345          * alen defines how much bytes we have to send.
 346          */
 347         /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
 348         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 349         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 350         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 351
 352         while (--alen >= 0) {
 353                 PRINTD(("i2c_read: send memory word address byte %1d\n", alen));
 354                 msg.condition = I2C_COND_NORMAL;
 355                 msg.acknack   = I2C_ACKNAK_WAITACK;
 356                 msg.direction = I2C_WRITE;
 357                 msg.data      = addr_bytes[alen];
 358                 if (i2c_transfer(&msg))
 359                         return -1;
 360         }
 361
 362         /* start read sequence */
 363         PRINTD(("i2c_read: start read sequence\n"));
 364         msg.condition = I2C_COND_START;
 365         msg.acknack   = I2C_ACKNAK_WAITACK;
 366         msg.direction = I2C_WRITE;
 367         msg.data      = (chip << 1);
 368         msg.data     |= 0x01;
 369         if (i2c_transfer(&msg))
 370                 return -1;
 371
 372         /* read bytes; send NACK at last byte */
 373         while (len--) {
 374                 if (len == 0) {
 375                         msg.condition = I2C_COND_STOP;
 376                         msg.acknack   = I2C_ACKNAK_SENDNAK;
 377                 } else {
 378                         msg.condition = I2C_COND_NORMAL;
 379                         msg.acknack   = I2C_ACKNAK_SENDACK;
 380                 }
 381
 382                 msg.direction = I2C_READ;
 383                 msg.data      = 0x00;
 384                 if (i2c_transfer(&msg))
 385                         return -1;
 386
 387                 *buffer = msg.data;
 388                 PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n",
 389                         (unsigned int)buffer, *buffer));
 390                 buffer++;
 391         }
 392
 393         i2c_reset();
 394
 395         return 0;
 396 }
 397
 398 /*
 399  * i2c_write: -  Write multiple bytes to an i2c device
 400  *
 401  * The higher level routines take into account that this function is only
 402  * called with len < page length of the device (see configuration file)
 403  *
 404  * @chip:       address of the chip which is to be written
 405  * @addr:       i2c data address within the chip
 406  * @alen:       length of the i2c data address (1..2 bytes)
 407  * @buffer:     where to find the data to be written
 408  * @len:        how much byte do we want to read
 409  * @return:     0 in case of success
 410  */
 411 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 412 {
 413         struct i2c_msg msg;
 414         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 415
 416         PRINTD(("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 417                 "len=0x%02x)\n", chip, addr, alen, len));
 418
 419         i2c_reset();
 420
 421         /* chip address write */
 422         PRINTD(("i2c_write: chip address write\n"));
 423         msg.condition = I2C_COND_START;
 424         msg.acknack   = I2C_ACKNAK_WAITACK;
 425         msg.direction = I2C_WRITE;
 426         msg.data = (chip << 1);
 427         msg.data &= 0xFE;
 428         if (i2c_transfer(&msg))
 429                 return -1;
 430
 431         /*
 432          * send memory address bytes;
 433          * alen defines how much bytes we have to send.
 434          */
 435         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 436         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 437         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 438
 439         while (--alen >= 0) {
 440                 PRINTD(("i2c_write: send memory word address\n"));
 441                 msg.condition = I2C_COND_NORMAL;
 442                 msg.acknack   = I2C_ACKNAK_WAITACK;
 443                 msg.direction = I2C_WRITE;
 444                 msg.data      = addr_bytes[alen];
 445                 if (i2c_transfer(&msg))
 446                         return -1;
 447         }
 448
 449         /* write bytes; send NACK at last byte */
 450         while (len--) {
 451                 PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n",
 452                         (unsigned int)buffer, *buffer));
 453
 454                 if (len == 0)
 455                         msg.condition = I2C_COND_STOP;
 456                 else
 457                         msg.condition = I2C_COND_NORMAL;
 458
 459                 msg.acknack   = I2C_ACKNAK_WAITACK;
 460                 msg.direction = I2C_WRITE;
 461                 msg.data      = *(buffer++);
 462
 463                 if (i2c_transfer(&msg))
 464                         return -1;
 465         }
 466
 467         i2c_reset();
 468
 469         return 0;
 470 }
 471 #endif  /* CONFIG_HARD_I2C */