drivers/i2c/mv_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2000
   4  * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
   5  *
   6  * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Marius Groeger <mgroeger@sysgo.de>
   8  *
   9  * (C) Copyright 2003 Pengutronix e.K.
  10  * Robert Schwebel <r.schwebel@pengutronix.de>
  11  *
  12  * (C) Copyright 2011 Marvell Inc.
  13  * Lei Wen <leiwen@marvell.com>
  14  *
  15  * Back ported to the 8xx platform (from the 8260 platform) by
  16  * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
  17  */
  18
  19 #include <common.h>
  20 #include <dm.h>
  21 #include <i2c.h>
  22 #include <log.h>
  23 #include <asm/io.h>
  24 #include <linux/delay.h>
  25 #include "mv_i2c.h"
  26
  27 /* All transfers are described by this data structure */
  28 struct mv_i2c_msg {
  29         u8 condition;
  30         u8 acknack;
  31         u8 direction;
  32         u8 data;
  33 };
  34
  35 #ifdef CONFIG_ARMADA_3700
  36 /* Armada 3700 has no padding between the registers */
  37 struct mv_i2c {
  38         u32 ibmr;
  39         u32 idbr;
  40         u32 icr;
  41         u32 isr;
  42         u32 isar;
  43 };
  44 #else
  45 struct mv_i2c {
  46         u32 ibmr;
  47         u32 pad0;
  48         u32 idbr;
  49         u32 pad1;
  50         u32 icr;
  51         u32 pad2;
  52         u32 isr;
  53         u32 pad3;
  54         u32 isar;
  55 };
  56 #endif
  57
  58 /*
  59  * Dummy implementation that can be overwritten by a board
  60  * specific function
  61  */
  62 __weak void i2c_clk_enable(void)
  63 {
  64 }
  65
  66 /*
  67  * i2c_reset: - reset the host controller
  68  *
  69  */
  70 static void i2c_reset(struct mv_i2c *base)
  71 {
  72         u32 icr_mode;
  73
  74         /* Save bus mode (standard or fast speed) for later use */
  75         icr_mode = readl(&base->icr) & ICR_MODE_MASK;
  76         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
  77         writel(readl(&base->icr) | ICR_UR, &base->icr);   /* reset the unit */
  78         udelay(100);
  79         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
  80
  81         i2c_clk_enable();
  82
  83         writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
  84         /* set control reg values */
  85         writel(I2C_ICR_INIT | icr_mode, &base->icr);
  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(struct mv_i2c *base, 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 static int i2c_transfer(struct mv_i2c *base, struct mv_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(base, 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(base, 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(base, 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(base, 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(base, 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         debug("i2c_transfer: error: 'msg' is empty\n");
 205         ret = -1;
 206         goto i2c_transfer_finish;
 207
 208 transfer_error_transmit_timeout:
 209         debug("i2c_transfer: error: transmit timeout\n");
 210         ret = -2;
 211         goto i2c_transfer_finish;
 212
 213 transfer_error_ack_missing:
 214         debug("i2c_transfer: error: ACK missing\n");
 215         ret = -3;
 216         goto i2c_transfer_finish;
 217
 218 transfer_error_receive_timeout:
 219         debug("i2c_transfer: error: receive timeout\n");
 220         ret = -4;
 221         goto i2c_transfer_finish;
 222
 223 transfer_error_illegal_param:
 224         debug("i2c_transfer: error: illegal parameters\n");
 225         ret = -5;
 226         goto i2c_transfer_finish;
 227
 228 transfer_error_bus_busy:
 229         debug("i2c_transfer: error: bus is busy\n");
 230         ret = -6;
 231         goto i2c_transfer_finish;
 232
 233 i2c_transfer_finish:
 234         debug("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr));
 235         i2c_reset(base);
 236         return ret;
 237 }
 238
 239 static int __i2c_read(struct mv_i2c *base, uchar chip, u8 *addr, int alen,
 240                       uchar *buffer, int len)
 241 {
 242         struct mv_i2c_msg msg;
 243
 244         debug("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 245               "len=0x%02x)\n", chip, *addr, alen, len);
 246
 247         if (len == 0) {
 248                 printf("reading zero byte is invalid\n");
 249                 return -EINVAL;
 250         }
 251
 252         i2c_reset(base);
 253
 254         /* dummy chip address write */
 255         debug("i2c_read: dummy chip address write\n");
 256         msg.condition = I2C_COND_START;
 257         msg.acknack   = I2C_ACKNAK_WAITACK;
 258         msg.direction = I2C_WRITE;
 259         msg.data = (chip << 1);
 260         msg.data &= 0xFE;
 261         if (i2c_transfer(base, &msg))
 262                 return -1;
 263
 264         /*
 265          * send memory address bytes;
 266          * alen defines how much bytes we have to send.
 267          */
 268         while (--alen >= 0) {
 269                 debug("i2c_read: send address byte %02x (alen=%d)\n",
 270                       *addr, alen);
 271                 msg.condition = I2C_COND_NORMAL;
 272                 msg.acknack   = I2C_ACKNAK_WAITACK;
 273                 msg.direction = I2C_WRITE;
 274                 msg.data      = addr[alen];
 275                 if (i2c_transfer(base, &msg))
 276                         return -1;
 277         }
 278
 279         /* start read sequence */
 280         debug("i2c_read: start read sequence\n");
 281         msg.condition = I2C_COND_START;
 282         msg.acknack   = I2C_ACKNAK_WAITACK;
 283         msg.direction = I2C_WRITE;
 284         msg.data      = (chip << 1);
 285         msg.data     |= 0x01;
 286         if (i2c_transfer(base, &msg))
 287                 return -1;
 288
 289         /* read bytes; send NACK at last byte */
 290         while (len--) {
 291                 if (len == 0) {
 292                         msg.condition = I2C_COND_STOP;
 293                         msg.acknack   = I2C_ACKNAK_SENDNAK;
 294                 } else {
 295                         msg.condition = I2C_COND_NORMAL;
 296                         msg.acknack   = I2C_ACKNAK_SENDACK;
 297                 }
 298
 299                 msg.direction = I2C_READ;
 300                 msg.data      = 0x00;
 301                 if (i2c_transfer(base, &msg))
 302                         return -1;
 303
 304                 *buffer = msg.data;
 305                 debug("i2c_read: reading byte (%p)=0x%02x\n",
 306                       buffer, *buffer);
 307                 buffer++;
 308         }
 309
 310         i2c_reset(base);
 311
 312         return 0;
 313 }
 314
 315 static int __i2c_write(struct mv_i2c *base, uchar chip, u8 *addr, int alen,
 316                        uchar *buffer, int len)
 317 {
 318         struct mv_i2c_msg msg;
 319
 320         debug("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 321               "len=0x%02x)\n", chip, *addr, alen, len);
 322
 323         i2c_reset(base);
 324
 325         /* chip address write */
 326         debug("i2c_write: chip address write\n");
 327         msg.condition = I2C_COND_START;
 328         msg.acknack   = I2C_ACKNAK_WAITACK;
 329         msg.direction = I2C_WRITE;
 330         msg.data = (chip << 1);
 331         msg.data &= 0xFE;
 332         if (i2c_transfer(base, &msg))
 333                 return -1;
 334
 335         /*
 336          * send memory address bytes;
 337          * alen defines how much bytes we have to send.
 338          */
 339         while (--alen >= 0) {
 340                 debug("i2c_read: send address byte %02x (alen=%d)\n",
 341                       *addr, alen);
 342                 msg.condition = I2C_COND_NORMAL;
 343                 msg.acknack   = I2C_ACKNAK_WAITACK;
 344                 msg.direction = I2C_WRITE;
 345                 msg.data      = addr[alen];
 346                 if (i2c_transfer(base, &msg))
 347                         return -1;
 348         }
 349
 350         /* write bytes; send NACK at last byte */
 351         while (len--) {
 352                 debug("i2c_write: writing byte (%p)=0x%02x\n",
 353                       buffer, *buffer);
 354
 355                 if (len == 0)
 356                         msg.condition = I2C_COND_STOP;
 357                 else
 358                         msg.condition = I2C_COND_NORMAL;
 359
 360                 msg.acknack   = I2C_ACKNAK_WAITACK;
 361                 msg.direction = I2C_WRITE;
 362                 msg.data      = *(buffer++);
 363
 364                 if (i2c_transfer(base, &msg))
 365                         return -1;
 366         }
 367
 368         i2c_reset(base);
 369
 370         return 0;
 371 }
 372
 373 #ifndef CONFIG_DM_I2C
 374
 375 static struct mv_i2c *base_glob;
 376
 377 static void i2c_board_init(struct mv_i2c *base)
 378 {
 379 #ifdef CONFIG_SYS_I2C_INIT_BOARD
 380         u32 icr;
 381         /*
 382          * call board specific i2c bus reset routine before accessing the
 383          * environment, which might be in a chip on that bus. For details
 384          * about this problem see doc/I2C_Edge_Conditions.
 385          *
 386          * disable I2C controller first, otherwhise it thinks we want to
 387          * talk to the slave port...
 388          */
 389         icr = readl(&base->icr);
 390         writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
 391
 392         i2c_init_board();
 393
 394         writel(icr, &base->icr);
 395 #endif
 396 }
 397
 398 #ifdef CONFIG_I2C_MULTI_BUS
 399 static unsigned long i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG;
 400 static unsigned int bus_initialized[CONFIG_MV_I2C_NUM];
 401 static unsigned int current_bus;
 402
 403 int i2c_set_bus_num(unsigned int bus)
 404 {
 405         if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) {
 406                 printf("Bad bus: %d\n", bus);
 407                 return -1;
 408         }
 409
 410         base_glob = (struct mv_i2c *)i2c_regs[bus];
 411         current_bus = bus;
 412
 413         if (!bus_initialized[current_bus]) {
 414                 i2c_board_init(base_glob);
 415                 bus_initialized[current_bus] = 1;
 416         }
 417
 418         return 0;
 419 }
 420
 421 unsigned int i2c_get_bus_num(void)
 422 {
 423         return current_bus;
 424 }
 425 #endif
 426
 427 /* API Functions */
 428 void i2c_init(int speed, int slaveaddr)
 429 {
 430         u32 val;
 431
 432 #ifdef CONFIG_I2C_MULTI_BUS
 433         current_bus = 0;
 434         base_glob = (struct mv_i2c *)i2c_regs[current_bus];
 435 #else
 436         base_glob = (struct mv_i2c *)CONFIG_MV_I2C_REG;
 437 #endif
 438
 439         if (speed > I2C_SPEED_STANDARD_RATE)
 440                 val = ICR_FM;
 441         else
 442                 val = ICR_SM;
 443         clrsetbits_le32(&base_glob->icr, ICR_MODE_MASK, val);
 444
 445         i2c_board_init(base_glob);
 446 }
 447
 448 static int __i2c_probe_chip(struct mv_i2c *base, uchar chip)
 449 {
 450         struct mv_i2c_msg msg;
 451
 452         i2c_reset(base);
 453
 454         msg.condition = I2C_COND_START;
 455         msg.acknack   = I2C_ACKNAK_WAITACK;
 456         msg.direction = I2C_WRITE;
 457         msg.data      = (chip << 1) + 1;
 458         if (i2c_transfer(base, &msg))
 459                 return -1;
 460
 461         msg.condition = I2C_COND_STOP;
 462         msg.acknack   = I2C_ACKNAK_SENDNAK;
 463         msg.direction = I2C_READ;
 464         msg.data      = 0x00;
 465         if (i2c_transfer(base, &msg))
 466                 return -1;
 467
 468         return 0;
 469 }
 470
 471 /*
 472  * i2c_probe: - Test if a chip answers for a given i2c address
 473  *
 474  * @chip:       address of the chip which is searched for
 475  * @return:     0 if a chip was found, -1 otherwhise
 476  */
 477 int i2c_probe(uchar chip)
 478 {
 479         return __i2c_probe_chip(base_glob, chip);
 480 }
 481
 482 /*
 483  * i2c_read: - Read multiple bytes from an i2c device
 484  *
 485  * The higher level routines take into account that this function is only
 486  * called with len < page length of the device (see configuration file)
 487  *
 488  * @chip:      address of the chip which is to be read
 489  * @addr:      i2c data address within the chip
 490  * @alen:      length of the i2c data address (1..2 bytes)
 491  * @buffer:    where to write the data
 492  * @len:       how much byte do we want to read
 493  * @return:    0 in case of success
 494  */
 495 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 496 {
 497         u8 addr_bytes[4];
 498
 499         addr_bytes[0] = (addr >> 0) & 0xFF;
 500         addr_bytes[1] = (addr >> 8) & 0xFF;
 501         addr_bytes[2] = (addr >> 16) & 0xFF;
 502         addr_bytes[3] = (addr >> 24) & 0xFF;
 503
 504         return __i2c_read(base_glob, chip, addr_bytes, alen, buffer, len);
 505 }
 506
 507 /*
 508  * i2c_write: -  Write multiple bytes to an i2c device
 509  *
 510  * The higher level routines take into account that this function is only
 511  * called with len < page length of the device (see configuration file)
 512  *
 513  * @chip:       address of the chip which is to be written
 514  * @addr:       i2c data address within the chip
 515  * @alen:       length of the i2c data address (1..2 bytes)
 516  * @buffer:     where to find the data to be written
 517  * @len:        how much byte do we want to read
 518  * @return:     0 in case of success
 519  */
 520 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 521 {
 522         u8 addr_bytes[4];
 523
 524         addr_bytes[0] = (addr >> 0) & 0xFF;
 525         addr_bytes[1] = (addr >> 8) & 0xFF;
 526         addr_bytes[2] = (addr >> 16) & 0xFF;
 527         addr_bytes[3] = (addr >> 24) & 0xFF;
 528
 529         return __i2c_write(base_glob, chip, addr_bytes, alen, buffer, len);
 530 }
 531
 532 #else /* CONFIG_DM_I2C */
 533
 534 struct mv_i2c_priv {
 535         struct mv_i2c *base;
 536 };
 537
 538 static int mv_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
 539 {
 540         struct mv_i2c_priv *i2c = dev_get_priv(bus);
 541         struct i2c_msg *dmsg, *omsg, dummy;
 542
 543         memset(&dummy, 0, sizeof(struct i2c_msg));
 544
 545         /*
 546          * We expect either two messages (one with an offset and one with the
 547          * actual data) or one message (just data or offset/data combined)
 548          */
 549         if (nmsgs > 2 || nmsgs == 0) {
 550                 debug("%s: Only one or two messages are supported.", __func__);
 551                 return -1;
 552         }
 553
 554         omsg = nmsgs == 1 ? &dummy : msg;
 555         dmsg = nmsgs == 1 ? msg : msg + 1;
 556
 557         if (dmsg->flags & I2C_M_RD)
 558                 return __i2c_read(i2c->base, dmsg->addr, omsg->buf,
 559                                   omsg->len, dmsg->buf, dmsg->len);
 560         else
 561                 return __i2c_write(i2c->base, dmsg->addr, omsg->buf,
 562                                    omsg->len, dmsg->buf, dmsg->len);
 563 }
 564
 565 static int mv_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 566 {
 567         struct mv_i2c_priv *priv = dev_get_priv(bus);
 568         u32 val;
 569
 570         if (speed > I2C_SPEED_STANDARD_RATE)
 571                 val = ICR_FM;
 572         else
 573                 val = ICR_SM;
 574         clrsetbits_le32(&priv->base->icr, ICR_MODE_MASK, val);
 575
 576         return 0;
 577 }
 578
 579 static int mv_i2c_probe(struct udevice *bus)
 580 {
 581         struct mv_i2c_priv *priv = dev_get_priv(bus);
 582
 583         priv->base = (void *)devfdt_get_addr_ptr(bus);
 584
 585         return 0;
 586 }
 587
 588 static const struct dm_i2c_ops mv_i2c_ops = {
 589         .xfer           = mv_i2c_xfer,
 590         .set_bus_speed  = mv_i2c_set_bus_speed,
 591 };
 592
 593 static const struct udevice_id mv_i2c_ids[] = {
 594         { .compatible = "marvell,armada-3700-i2c" },
 595         { }
 596 };
 597
 598 U_BOOT_DRIVER(i2c_mv) = {
 599         .name   = "i2c_mv",
 600         .id     = UCLASS_I2C,
 601         .of_match = mv_i2c_ids,
 602         .probe  = mv_i2c_probe,
 603         .priv_auto_alloc_size = sizeof(struct mv_i2c_priv),
 604         .ops    = &mv_i2c_ops,
 605 };
 606 #endif /* CONFIG_DM_I2C */