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 <dm.h> 22 #include <i2c.h> 23 #include <asm/io.h> 24 #include "mv_i2c.h" 25 26 /* All transfers are described by this data structure */ 27 struct mv_i2c_msg { 28 u8 condition; 29 u8 acknack; 30 u8 direction; 31 u8 data; 32 }; 33 34 #ifdef CONFIG_ARMADA_3700 35 /* Armada 3700 has no padding between the registers */ 36 struct mv_i2c { 37 u32 ibmr; 38 u32 idbr; 39 u32 icr; 40 u32 isr; 41 u32 isar; 42 }; 43 #else 44 struct mv_i2c { 45 u32 ibmr; 46 u32 pad0; 47 u32 idbr; 48 u32 pad1; 49 u32 icr; 50 u32 pad2; 51 u32 isr; 52 u32 pad3; 53 u32 isar; 54 }; 55 #endif 56 57 /* 58 * Dummy implementation that can be overwritten by a board 59 * specific function 60 */ 61 __weak void i2c_clk_enable(void) 62 { 63 } 64 65 /* 66 * i2c_reset: - reset the host controller 67 * 68 */ 69 static void i2c_reset(struct mv_i2c *base) 70 { 71 u32 icr_mode; 72 73 /* Save bus mode (standard or fast speed) for later use */ 74 icr_mode = readl(&base->icr) & ICR_MODE_MASK; 75 writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */ 76 writel(readl(&base->icr) | ICR_UR, &base->icr); /* reset the unit */ 77 udelay(100); 78 writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */ 79 80 i2c_clk_enable(); 81 82 writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */ 83 /* set control reg values */ 84 writel(I2C_ICR_INIT | icr_mode, &base->icr); 85 writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */ 86 writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */ 87 udelay(100); 88 } 89 90 /* 91 * i2c_isr_set_cleared: - wait until certain bits of the I2C status register 92 * are set and cleared 93 * 94 * @return: 1 in case of success, 0 means timeout (no match within 10 ms). 95 */ 96 static int i2c_isr_set_cleared(struct mv_i2c *base, unsigned long set_mask, 97 unsigned long cleared_mask) 98 { 99 int timeout = 1000, isr; 100 101 do { 102 isr = readl(&base->isr); 103 udelay(10); 104 if (timeout-- < 0) 105 return 0; 106 } while (((isr & set_mask) != set_mask) 107 || ((isr & cleared_mask) != 0)); 108 109 return 1; 110 } 111 112 /* 113 * i2c_transfer: - Transfer one byte over the i2c bus 114 * 115 * This function can tranfer a byte over the i2c bus in both directions. 116 * It is used by the public API functions. 117 * 118 * @return: 0: transfer successful 119 * -1: message is empty 120 * -2: transmit timeout 121 * -3: ACK missing 122 * -4: receive timeout 123 * -5: illegal parameters 124 * -6: bus is busy and couldn't be aquired 125 */ 126 static int i2c_transfer(struct mv_i2c *base, struct mv_i2c_msg *msg) 127 { 128 int ret; 129 130 if (!msg) 131 goto transfer_error_msg_empty; 132 133 switch (msg->direction) { 134 case I2C_WRITE: 135 /* check if bus is not busy */ 136 if (!i2c_isr_set_cleared(base, 0, ISR_IBB)) 137 goto transfer_error_bus_busy; 138 139 /* start transmission */ 140 writel(readl(&base->icr) & ~ICR_START, &base->icr); 141 writel(readl(&base->icr) & ~ICR_STOP, &base->icr); 142 writel(msg->data, &base->idbr); 143 if (msg->condition == I2C_COND_START) 144 writel(readl(&base->icr) | ICR_START, &base->icr); 145 if (msg->condition == I2C_COND_STOP) 146 writel(readl(&base->icr) | ICR_STOP, &base->icr); 147 if (msg->acknack == I2C_ACKNAK_SENDNAK) 148 writel(readl(&base->icr) | ICR_ACKNAK, &base->icr); 149 if (msg->acknack == I2C_ACKNAK_SENDACK) 150 writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr); 151 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr); 152 writel(readl(&base->icr) | ICR_TB, &base->icr); 153 154 /* transmit register empty? */ 155 if (!i2c_isr_set_cleared(base, ISR_ITE, 0)) 156 goto transfer_error_transmit_timeout; 157 158 /* clear 'transmit empty' state */ 159 writel(readl(&base->isr) | ISR_ITE, &base->isr); 160 161 /* wait for ACK from slave */ 162 if (msg->acknack == I2C_ACKNAK_WAITACK) 163 if (!i2c_isr_set_cleared(base, 0, ISR_ACKNAK)) 164 goto transfer_error_ack_missing; 165 break; 166 167 case I2C_READ: 168 169 /* check if bus is not busy */ 170 if (!i2c_isr_set_cleared(base, 0, ISR_IBB)) 171 goto transfer_error_bus_busy; 172 173 /* start receive */ 174 writel(readl(&base->icr) & ~ICR_START, &base->icr); 175 writel(readl(&base->icr) & ~ICR_STOP, &base->icr); 176 if (msg->condition == I2C_COND_START) 177 writel(readl(&base->icr) | ICR_START, &base->icr); 178 if (msg->condition == I2C_COND_STOP) 179 writel(readl(&base->icr) | ICR_STOP, &base->icr); 180 if (msg->acknack == I2C_ACKNAK_SENDNAK) 181 writel(readl(&base->icr) | ICR_ACKNAK, &base->icr); 182 if (msg->acknack == I2C_ACKNAK_SENDACK) 183 writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr); 184 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr); 185 writel(readl(&base->icr) | ICR_TB, &base->icr); 186 187 /* receive register full? */ 188 if (!i2c_isr_set_cleared(base, ISR_IRF, 0)) 189 goto transfer_error_receive_timeout; 190 191 msg->data = readl(&base->idbr); 192 193 /* clear 'receive empty' state */ 194 writel(readl(&base->isr) | ISR_IRF, &base->isr); 195 break; 196 default: 197 goto transfer_error_illegal_param; 198 } 199 200 return 0; 201 202 transfer_error_msg_empty: 203 debug("i2c_transfer: error: 'msg' is empty\n"); 204 ret = -1; 205 goto i2c_transfer_finish; 206 207 transfer_error_transmit_timeout: 208 debug("i2c_transfer: error: transmit timeout\n"); 209 ret = -2; 210 goto i2c_transfer_finish; 211 212 transfer_error_ack_missing: 213 debug("i2c_transfer: error: ACK missing\n"); 214 ret = -3; 215 goto i2c_transfer_finish; 216 217 transfer_error_receive_timeout: 218 debug("i2c_transfer: error: receive timeout\n"); 219 ret = -4; 220 goto i2c_transfer_finish; 221 222 transfer_error_illegal_param: 223 debug("i2c_transfer: error: illegal parameters\n"); 224 ret = -5; 225 goto i2c_transfer_finish; 226 227 transfer_error_bus_busy: 228 debug("i2c_transfer: error: bus is busy\n"); 229 ret = -6; 230 goto i2c_transfer_finish; 231 232 i2c_transfer_finish: 233 debug("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr)); 234 i2c_reset(base); 235 return ret; 236 } 237 238 static int __i2c_read(struct mv_i2c *base, uchar chip, u8 *addr, int alen, 239 uchar *buffer, int len) 240 { 241 struct mv_i2c_msg msg; 242 243 debug("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, " 244 "len=0x%02x)\n", chip, *addr, alen, len); 245 246 if (len == 0) { 247 printf("reading zero byte is invalid\n"); 248 return -EINVAL; 249 } 250 251 i2c_reset(base); 252 253 /* dummy chip address write */ 254 debug("i2c_read: dummy chip address write\n"); 255 msg.condition = I2C_COND_START; 256 msg.acknack = I2C_ACKNAK_WAITACK; 257 msg.direction = I2C_WRITE; 258 msg.data = (chip << 1); 259 msg.data &= 0xFE; 260 if (i2c_transfer(base, &msg)) 261 return -1; 262 263 /* 264 * send memory address bytes; 265 * alen defines how much bytes we have to send. 266 */ 267 while (--alen >= 0) { 268 debug("i2c_read: send address byte %02x (alen=%d)\n", 269 *addr, alen); 270 msg.condition = I2C_COND_NORMAL; 271 msg.acknack = I2C_ACKNAK_WAITACK; 272 msg.direction = I2C_WRITE; 273 msg.data = addr[alen]; 274 if (i2c_transfer(base, &msg)) 275 return -1; 276 } 277 278 /* start read sequence */ 279 debug("i2c_read: start read sequence\n"); 280 msg.condition = I2C_COND_START; 281 msg.acknack = I2C_ACKNAK_WAITACK; 282 msg.direction = I2C_WRITE; 283 msg.data = (chip << 1); 284 msg.data |= 0x01; 285 if (i2c_transfer(base, &msg)) 286 return -1; 287 288 /* read bytes; send NACK at last byte */ 289 while (len--) { 290 if (len == 0) { 291 msg.condition = I2C_COND_STOP; 292 msg.acknack = I2C_ACKNAK_SENDNAK; 293 } else { 294 msg.condition = I2C_COND_NORMAL; 295 msg.acknack = I2C_ACKNAK_SENDACK; 296 } 297 298 msg.direction = I2C_READ; 299 msg.data = 0x00; 300 if (i2c_transfer(base, &msg)) 301 return -1; 302 303 *buffer = msg.data; 304 debug("i2c_read: reading byte (%p)=0x%02x\n", 305 buffer, *buffer); 306 buffer++; 307 } 308 309 i2c_reset(base); 310 311 return 0; 312 } 313 314 static int __i2c_write(struct mv_i2c *base, uchar chip, u8 *addr, int alen, 315 uchar *buffer, int len) 316 { 317 struct mv_i2c_msg msg; 318 319 debug("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, " 320 "len=0x%02x)\n", chip, *addr, alen, len); 321 322 i2c_reset(base); 323 324 /* chip address write */ 325 debug("i2c_write: chip address write\n"); 326 msg.condition = I2C_COND_START; 327 msg.acknack = I2C_ACKNAK_WAITACK; 328 msg.direction = I2C_WRITE; 329 msg.data = (chip << 1); 330 msg.data &= 0xFE; 331 if (i2c_transfer(base, &msg)) 332 return -1; 333 334 /* 335 * send memory address bytes; 336 * alen defines how much bytes we have to send. 337 */ 338 while (--alen >= 0) { 339 debug("i2c_read: send address byte %02x (alen=%d)\n", 340 *addr, alen); 341 msg.condition = I2C_COND_NORMAL; 342 msg.acknack = I2C_ACKNAK_WAITACK; 343 msg.direction = I2C_WRITE; 344 msg.data = addr[alen]; 345 if (i2c_transfer(base, &msg)) 346 return -1; 347 } 348 349 /* write bytes; send NACK at last byte */ 350 while (len--) { 351 debug("i2c_write: writing byte (%p)=0x%02x\n", 352 buffer, *buffer); 353 354 if (len == 0) 355 msg.condition = I2C_COND_STOP; 356 else 357 msg.condition = I2C_COND_NORMAL; 358 359 msg.acknack = I2C_ACKNAK_WAITACK; 360 msg.direction = I2C_WRITE; 361 msg.data = *(buffer++); 362 363 if (i2c_transfer(base, &msg)) 364 return -1; 365 } 366 367 i2c_reset(base); 368 369 return 0; 370 } 371 372 #ifndef CONFIG_DM_I2C 373 374 static struct mv_i2c *base_glob; 375 376 static void i2c_board_init(struct mv_i2c *base) 377 { 378 #ifdef CONFIG_SYS_I2C_INIT_BOARD 379 u32 icr; 380 /* 381 * call board specific i2c bus reset routine before accessing the 382 * environment, which might be in a chip on that bus. For details 383 * about this problem see doc/I2C_Edge_Conditions. 384 * 385 * disable I2C controller first, otherwhise it thinks we want to 386 * talk to the slave port... 387 */ 388 icr = readl(&base->icr); 389 writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr); 390 391 i2c_init_board(); 392 393 writel(icr, &base->icr); 394 #endif 395 } 396 397 #ifdef CONFIG_I2C_MULTI_BUS 398 static unsigned long i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG; 399 static unsigned int bus_initialized[CONFIG_MV_I2C_NUM]; 400 static unsigned int current_bus; 401 402 int i2c_set_bus_num(unsigned int bus) 403 { 404 if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) { 405 printf("Bad bus: %d\n", bus); 406 return -1; 407 } 408 409 base_glob = (struct mv_i2c *)i2c_regs[bus]; 410 current_bus = bus; 411 412 if (!bus_initialized[current_bus]) { 413 i2c_board_init(base_glob); 414 bus_initialized[current_bus] = 1; 415 } 416 417 return 0; 418 } 419 420 unsigned int i2c_get_bus_num(void) 421 { 422 return current_bus; 423 } 424 #endif 425 426 /* API Functions */ 427 void i2c_init(int speed, int slaveaddr) 428 { 429 u32 val; 430 431 #ifdef CONFIG_I2C_MULTI_BUS 432 current_bus = 0; 433 base_glob = (struct mv_i2c *)i2c_regs[current_bus]; 434 #else 435 base_glob = (struct mv_i2c *)CONFIG_MV_I2C_REG; 436 #endif 437 438 if (speed > 100000) 439 val = ICR_FM; 440 else 441 val = ICR_SM; 442 clrsetbits_le32(&base_glob->icr, ICR_MODE_MASK, val); 443 444 i2c_board_init(base_glob); 445 } 446 447 static int __i2c_probe_chip(struct mv_i2c *base, uchar chip) 448 { 449 struct mv_i2c_msg msg; 450 451 i2c_reset(base); 452 453 msg.condition = I2C_COND_START; 454 msg.acknack = I2C_ACKNAK_WAITACK; 455 msg.direction = I2C_WRITE; 456 msg.data = (chip << 1) + 1; 457 if (i2c_transfer(base, &msg)) 458 return -1; 459 460 msg.condition = I2C_COND_STOP; 461 msg.acknack = I2C_ACKNAK_SENDNAK; 462 msg.direction = I2C_READ; 463 msg.data = 0x00; 464 if (i2c_transfer(base, &msg)) 465 return -1; 466 467 return 0; 468 } 469 470 /* 471 * i2c_probe: - Test if a chip answers for a given i2c address 472 * 473 * @chip: address of the chip which is searched for 474 * @return: 0 if a chip was found, -1 otherwhise 475 */ 476 int i2c_probe(uchar chip) 477 { 478 return __i2c_probe_chip(base_glob, chip); 479 } 480 481 /* 482 * i2c_read: - Read multiple bytes from an i2c device 483 * 484 * The higher level routines take into account that this function is only 485 * called with len < page length of the device (see configuration file) 486 * 487 * @chip: address of the chip which is to be read 488 * @addr: i2c data address within the chip 489 * @alen: length of the i2c data address (1..2 bytes) 490 * @buffer: where to write the data 491 * @len: how much byte do we want to read 492 * @return: 0 in case of success 493 */ 494 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) 495 { 496 u8 addr_bytes[4]; 497 498 addr_bytes[0] = (addr >> 0) & 0xFF; 499 addr_bytes[1] = (addr >> 8) & 0xFF; 500 addr_bytes[2] = (addr >> 16) & 0xFF; 501 addr_bytes[3] = (addr >> 24) & 0xFF; 502 503 return __i2c_read(base_glob, chip, addr_bytes, alen, buffer, len); 504 } 505 506 /* 507 * i2c_write: - Write multiple bytes to an i2c device 508 * 509 * The higher level routines take into account that this function is only 510 * called with len < page length of the device (see configuration file) 511 * 512 * @chip: address of the chip which is to be written 513 * @addr: i2c data address within the chip 514 * @alen: length of the i2c data address (1..2 bytes) 515 * @buffer: where to find the data to be written 516 * @len: how much byte do we want to read 517 * @return: 0 in case of success 518 */ 519 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) 520 { 521 u8 addr_bytes[4]; 522 523 addr_bytes[0] = (addr >> 0) & 0xFF; 524 addr_bytes[1] = (addr >> 8) & 0xFF; 525 addr_bytes[2] = (addr >> 16) & 0xFF; 526 addr_bytes[3] = (addr >> 24) & 0xFF; 527 528 return __i2c_write(base_glob, chip, addr_bytes, alen, buffer, len); 529 } 530 531 #else /* CONFIG_DM_I2C */ 532 533 struct mv_i2c_priv { 534 struct mv_i2c *base; 535 }; 536 537 static int mv_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) 538 { 539 struct mv_i2c_priv *i2c = dev_get_priv(bus); 540 struct i2c_msg *dmsg, *omsg, dummy; 541 542 memset(&dummy, 0, sizeof(struct i2c_msg)); 543 544 /* 545 * We expect either two messages (one with an offset and one with the 546 * actual data) or one message (just data or offset/data combined) 547 */ 548 if (nmsgs > 2 || nmsgs == 0) { 549 debug("%s: Only one or two messages are supported.", __func__); 550 return -1; 551 } 552 553 omsg = nmsgs == 1 ? &dummy : msg; 554 dmsg = nmsgs == 1 ? msg : msg + 1; 555 556 if (dmsg->flags & I2C_M_RD) 557 return __i2c_read(i2c->base, dmsg->addr, omsg->buf, 558 omsg->len, dmsg->buf, dmsg->len); 559 else 560 return __i2c_write(i2c->base, dmsg->addr, omsg->buf, 561 omsg->len, dmsg->buf, dmsg->len); 562 } 563 564 static int mv_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) 565 { 566 struct mv_i2c_priv *priv = dev_get_priv(bus); 567 u32 val; 568 569 if (speed > 100000) 570 val = ICR_FM; 571 else 572 val = ICR_SM; 573 clrsetbits_le32(&priv->base->icr, ICR_MODE_MASK, val); 574 575 return 0; 576 } 577 578 static int mv_i2c_probe(struct udevice *bus) 579 { 580 struct mv_i2c_priv *priv = dev_get_priv(bus); 581 582 priv->base = (void *)devfdt_get_addr_ptr(bus); 583 584 return 0; 585 } 586 587 static const struct dm_i2c_ops mv_i2c_ops = { 588 .xfer = mv_i2c_xfer, 589 .set_bus_speed = mv_i2c_set_bus_speed, 590 }; 591 592 static const struct udevice_id mv_i2c_ids[] = { 593 { .compatible = "marvell,armada-3700-i2c" }, 594 { } 595 }; 596 597 U_BOOT_DRIVER(i2c_mv) = { 598 .name = "i2c_mv", 599 .id = UCLASS_I2C, 600 .of_match = mv_i2c_ids, 601 .probe = mv_i2c_probe, 602 .priv_auto_alloc_size = sizeof(struct mv_i2c_priv), 603 .ops = &mv_i2c_ops, 604 }; 605 #endif /* CONFIG_DM_I2C */ 606