1 /* 2 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 3 * Copyright (c) 2010-2011 NVIDIA Corporation 4 * NVIDIA Corporation <www.nvidia.com> 5 * 6 * See file CREDITS for list of people who contributed to this 7 * project. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation; either version 2 of 12 * the License, or (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 22 * MA 02111-1307 USA 23 */ 24 25 #include <common.h> 26 #include <fdtdec.h> 27 #include <i2c.h> 28 #include <asm/io.h> 29 #include <asm/arch/clk_rst.h> 30 #include <asm/arch/clock.h> 31 #include <asm/arch/funcmux.h> 32 #include <asm/arch/gpio.h> 33 #include <asm/arch/pinmux.h> 34 #include <asm/arch/tegra_i2c.h> 35 36 DECLARE_GLOBAL_DATA_PTR; 37 38 static unsigned int i2c_bus_num; 39 40 /* Information about i2c controller */ 41 struct i2c_bus { 42 int id; 43 enum periph_id periph_id; 44 int speed; 45 int pinmux_config; 46 struct i2c_control *control; 47 struct i2c_ctlr *regs; 48 int is_dvc; /* DVC type, rather than I2C */ 49 int inited; /* bus is inited */ 50 }; 51 52 static struct i2c_bus i2c_controllers[TEGRA_I2C_NUM_CONTROLLERS]; 53 54 static void set_packet_mode(struct i2c_bus *i2c_bus) 55 { 56 u32 config; 57 58 config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK; 59 60 if (i2c_bus->is_dvc) { 61 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs; 62 63 writel(config, &dvc->cnfg); 64 } else { 65 writel(config, &i2c_bus->regs->cnfg); 66 /* 67 * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe 68 * issues, i.e., some slaves may be wrongly detected. 69 */ 70 setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK); 71 } 72 } 73 74 static void i2c_reset_controller(struct i2c_bus *i2c_bus) 75 { 76 /* Reset I2C controller. */ 77 reset_periph(i2c_bus->periph_id, 1); 78 79 /* re-program config register to packet mode */ 80 set_packet_mode(i2c_bus); 81 } 82 83 static void i2c_init_controller(struct i2c_bus *i2c_bus) 84 { 85 /* 86 * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8 87 * here, in section 23.3.1, but in fact we seem to need a factor of 88 * 16 to get the right frequency. 89 */ 90 clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH, 91 i2c_bus->speed * 2 * 8); 92 93 /* Reset I2C controller. */ 94 i2c_reset_controller(i2c_bus); 95 96 /* Configure I2C controller. */ 97 if (i2c_bus->is_dvc) { /* only for DVC I2C */ 98 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs; 99 100 setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK); 101 } 102 103 funcmux_select(i2c_bus->periph_id, i2c_bus->pinmux_config); 104 } 105 106 static void send_packet_headers( 107 struct i2c_bus *i2c_bus, 108 struct i2c_trans_info *trans, 109 u32 packet_id) 110 { 111 u32 data; 112 113 /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */ 114 data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT; 115 data |= packet_id << PKT_HDR1_PKT_ID_SHIFT; 116 data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT; 117 writel(data, &i2c_bus->control->tx_fifo); 118 debug("pkt header 1 sent (0x%x)\n", data); 119 120 /* prepare header2 */ 121 data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT; 122 writel(data, &i2c_bus->control->tx_fifo); 123 debug("pkt header 2 sent (0x%x)\n", data); 124 125 /* prepare IO specific header: configure the slave address */ 126 data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT; 127 128 /* Enable Read if it is not a write transaction */ 129 if (!(trans->flags & I2C_IS_WRITE)) 130 data |= PKT_HDR3_READ_MODE_MASK; 131 132 /* Write I2C specific header */ 133 writel(data, &i2c_bus->control->tx_fifo); 134 debug("pkt header 3 sent (0x%x)\n", data); 135 } 136 137 static int wait_for_tx_fifo_empty(struct i2c_control *control) 138 { 139 u32 count; 140 int timeout_us = I2C_TIMEOUT_USEC; 141 142 while (timeout_us >= 0) { 143 count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK) 144 >> TX_FIFO_EMPTY_CNT_SHIFT; 145 if (count == I2C_FIFO_DEPTH) 146 return 1; 147 udelay(10); 148 timeout_us -= 10; 149 } 150 151 return 0; 152 } 153 154 static int wait_for_rx_fifo_notempty(struct i2c_control *control) 155 { 156 u32 count; 157 int timeout_us = I2C_TIMEOUT_USEC; 158 159 while (timeout_us >= 0) { 160 count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK) 161 >> TX_FIFO_FULL_CNT_SHIFT; 162 if (count) 163 return 1; 164 udelay(10); 165 timeout_us -= 10; 166 } 167 168 return 0; 169 } 170 171 static int wait_for_transfer_complete(struct i2c_control *control) 172 { 173 int int_status; 174 int timeout_us = I2C_TIMEOUT_USEC; 175 176 while (timeout_us >= 0) { 177 int_status = readl(&control->int_status); 178 if (int_status & I2C_INT_NO_ACK_MASK) 179 return -int_status; 180 if (int_status & I2C_INT_ARBITRATION_LOST_MASK) 181 return -int_status; 182 if (int_status & I2C_INT_XFER_COMPLETE_MASK) 183 return 0; 184 185 udelay(10); 186 timeout_us -= 10; 187 } 188 189 return -1; 190 } 191 192 static int send_recv_packets(struct i2c_bus *i2c_bus, 193 struct i2c_trans_info *trans) 194 { 195 struct i2c_control *control = i2c_bus->control; 196 u32 int_status; 197 u32 words; 198 u8 *dptr; 199 u32 local; 200 uchar last_bytes; 201 int error = 0; 202 int is_write = trans->flags & I2C_IS_WRITE; 203 204 /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */ 205 int_status = readl(&control->int_status); 206 writel(int_status, &control->int_status); 207 208 send_packet_headers(i2c_bus, trans, 1); 209 210 words = DIV_ROUND_UP(trans->num_bytes, 4); 211 last_bytes = trans->num_bytes & 3; 212 dptr = trans->buf; 213 214 while (words) { 215 u32 *wptr = (u32 *)dptr; 216 217 if (is_write) { 218 /* deal with word alignment */ 219 if ((unsigned)dptr & 3) { 220 memcpy(&local, dptr, sizeof(u32)); 221 writel(local, &control->tx_fifo); 222 debug("pkt data sent (0x%x)\n", local); 223 } else { 224 writel(*wptr, &control->tx_fifo); 225 debug("pkt data sent (0x%x)\n", *wptr); 226 } 227 if (!wait_for_tx_fifo_empty(control)) { 228 error = -1; 229 goto exit; 230 } 231 } else { 232 if (!wait_for_rx_fifo_notempty(control)) { 233 error = -1; 234 goto exit; 235 } 236 /* 237 * for the last word, we read into our local buffer, 238 * in case that caller did not provide enough buffer. 239 */ 240 local = readl(&control->rx_fifo); 241 if ((words == 1) && last_bytes) 242 memcpy(dptr, (char *)&local, last_bytes); 243 else if ((unsigned)dptr & 3) 244 memcpy(dptr, &local, sizeof(u32)); 245 else 246 *wptr = local; 247 debug("pkt data received (0x%x)\n", local); 248 } 249 words--; 250 dptr += sizeof(u32); 251 } 252 253 if (wait_for_transfer_complete(control)) { 254 error = -1; 255 goto exit; 256 } 257 return 0; 258 exit: 259 /* error, reset the controller. */ 260 i2c_reset_controller(i2c_bus); 261 262 return error; 263 } 264 265 static int tegra2_i2c_write_data(u32 addr, u8 *data, u32 len) 266 { 267 int error; 268 struct i2c_trans_info trans_info; 269 270 trans_info.address = addr; 271 trans_info.buf = data; 272 trans_info.flags = I2C_IS_WRITE; 273 trans_info.num_bytes = len; 274 trans_info.is_10bit_address = 0; 275 276 error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info); 277 if (error) 278 debug("tegra2_i2c_write_data: Error (%d) !!!\n", error); 279 280 return error; 281 } 282 283 static int tegra2_i2c_read_data(u32 addr, u8 *data, u32 len) 284 { 285 int error; 286 struct i2c_trans_info trans_info; 287 288 trans_info.address = addr | 1; 289 trans_info.buf = data; 290 trans_info.flags = 0; 291 trans_info.num_bytes = len; 292 trans_info.is_10bit_address = 0; 293 294 error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info); 295 if (error) 296 debug("tegra2_i2c_read_data: Error (%d) !!!\n", error); 297 298 return error; 299 } 300 301 #ifndef CONFIG_OF_CONTROL 302 #error "Please enable device tree support to use this driver" 303 #endif 304 305 unsigned int i2c_get_bus_speed(void) 306 { 307 return i2c_controllers[i2c_bus_num].speed; 308 } 309 310 int i2c_set_bus_speed(unsigned int speed) 311 { 312 struct i2c_bus *i2c_bus; 313 314 i2c_bus = &i2c_controllers[i2c_bus_num]; 315 i2c_bus->speed = speed; 316 i2c_init_controller(i2c_bus); 317 318 return 0; 319 } 320 321 static int i2c_get_config(const void *blob, int node, struct i2c_bus *i2c_bus) 322 { 323 i2c_bus->regs = (struct i2c_ctlr *)fdtdec_get_addr(blob, node, "reg"); 324 325 /* 326 * We don't have a binding for pinmux yet. Leave it out for now. So 327 * far no one needs anything other than the default. 328 */ 329 i2c_bus->pinmux_config = FUNCMUX_DEFAULT; 330 i2c_bus->speed = fdtdec_get_int(blob, node, "clock-frequency", 0); 331 i2c_bus->periph_id = clock_decode_periph_id(blob, node); 332 333 /* 334 * We can't specify the pinmux config in the fdt, so I2C2 will not 335 * work on Seaboard. It normally has no devices on it anyway. 336 * You could add in this little hack if you need to use it. 337 * The correct solution is a pinmux binding in the fdt. 338 * 339 * if (i2c_bus->periph_id == PERIPH_ID_I2C2) 340 * i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA; 341 */ 342 if (i2c_bus->periph_id == -1) 343 return -FDT_ERR_NOTFOUND; 344 345 return 0; 346 } 347 348 /* 349 * Process a list of nodes, adding them to our list of I2C ports. 350 * 351 * @param blob fdt blob 352 * @param node_list list of nodes to process (any <=0 are ignored) 353 * @param count number of nodes to process 354 * @param is_dvc 1 if these are DVC ports, 0 if standard I2C 355 * @return 0 if ok, -1 on error 356 */ 357 static int process_nodes(const void *blob, int node_list[], int count, 358 int is_dvc) 359 { 360 struct i2c_bus *i2c_bus; 361 int i; 362 363 /* build the i2c_controllers[] for each controller */ 364 for (i = 0; i < count; i++) { 365 int node = node_list[i]; 366 367 if (node <= 0) 368 continue; 369 370 i2c_bus = &i2c_controllers[i]; 371 i2c_bus->id = i; 372 373 if (i2c_get_config(blob, node, i2c_bus)) { 374 printf("i2c_init_board: failed to decode bus %d\n", i); 375 return -1; 376 } 377 378 i2c_bus->is_dvc = is_dvc; 379 if (is_dvc) { 380 i2c_bus->control = 381 &((struct dvc_ctlr *)i2c_bus->regs)->control; 382 } else { 383 i2c_bus->control = &i2c_bus->regs->control; 384 } 385 debug("%s: controller bus %d at %p, periph_id %d, speed %d: ", 386 is_dvc ? "dvc" : "i2c", i, i2c_bus->regs, 387 i2c_bus->periph_id, i2c_bus->speed); 388 i2c_init_controller(i2c_bus); 389 debug("ok\n"); 390 i2c_bus->inited = 1; 391 392 /* Mark position as used */ 393 node_list[i] = -1; 394 } 395 396 return 0; 397 } 398 399 /* Sadly there is no error return from this function */ 400 void i2c_init_board(void) 401 { 402 int node_list[TEGRA_I2C_NUM_CONTROLLERS]; 403 const void *blob = gd->fdt_blob; 404 int count; 405 406 /* First get the normal i2c ports */ 407 count = fdtdec_find_aliases_for_id(blob, "i2c", 408 COMPAT_NVIDIA_TEGRA20_I2C, node_list, 409 TEGRA_I2C_NUM_CONTROLLERS); 410 if (process_nodes(blob, node_list, count, 0)) 411 return; 412 413 /* Now look for dvc ports */ 414 count = fdtdec_add_aliases_for_id(blob, "i2c", 415 COMPAT_NVIDIA_TEGRA20_DVC, node_list, 416 TEGRA_I2C_NUM_CONTROLLERS); 417 if (process_nodes(blob, node_list, count, 1)) 418 return; 419 } 420 421 void i2c_init(int speed, int slaveaddr) 422 { 423 /* This will override the speed selected in the fdt for that port */ 424 debug("i2c_init(speed=%u, slaveaddr=0x%x)\n", speed, slaveaddr); 425 i2c_set_bus_speed(speed); 426 } 427 428 /* i2c write version without the register address */ 429 int i2c_write_data(uchar chip, uchar *buffer, int len) 430 { 431 int rc; 432 433 debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len); 434 debug("write_data: "); 435 /* use rc for counter */ 436 for (rc = 0; rc < len; ++rc) 437 debug(" 0x%02x", buffer[rc]); 438 debug("\n"); 439 440 /* Shift 7-bit address over for lower-level i2c functions */ 441 rc = tegra2_i2c_write_data(chip << 1, buffer, len); 442 if (rc) 443 debug("i2c_write_data(): rc=%d\n", rc); 444 445 return rc; 446 } 447 448 /* i2c read version without the register address */ 449 int i2c_read_data(uchar chip, uchar *buffer, int len) 450 { 451 int rc; 452 453 debug("inside i2c_read_data():\n"); 454 /* Shift 7-bit address over for lower-level i2c functions */ 455 rc = tegra2_i2c_read_data(chip << 1, buffer, len); 456 if (rc) { 457 debug("i2c_read_data(): rc=%d\n", rc); 458 return rc; 459 } 460 461 debug("i2c_read_data: "); 462 /* reuse rc for counter*/ 463 for (rc = 0; rc < len; ++rc) 464 debug(" 0x%02x", buffer[rc]); 465 debug("\n"); 466 467 return 0; 468 } 469 470 /* Probe to see if a chip is present. */ 471 int i2c_probe(uchar chip) 472 { 473 int rc; 474 uchar reg; 475 476 debug("i2c_probe: addr=0x%x\n", chip); 477 reg = 0; 478 rc = i2c_write_data(chip, ®, 1); 479 if (rc) { 480 debug("Error probing 0x%x.\n", chip); 481 return 1; 482 } 483 return 0; 484 } 485 486 static int i2c_addr_ok(const uint addr, const int alen) 487 { 488 /* We support 7 or 10 bit addresses, so one or two bytes each */ 489 return alen == 1 || alen == 2; 490 } 491 492 /* Read bytes */ 493 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) 494 { 495 uint offset; 496 int i; 497 498 debug("i2c_read: chip=0x%x, addr=0x%x, len=0x%x\n", 499 chip, addr, len); 500 if (!i2c_addr_ok(addr, alen)) { 501 debug("i2c_read: Bad address %x.%d.\n", addr, alen); 502 return 1; 503 } 504 for (offset = 0; offset < len; offset++) { 505 if (alen) { 506 uchar data[alen]; 507 for (i = 0; i < alen; i++) { 508 data[alen - i - 1] = 509 (addr + offset) >> (8 * i); 510 } 511 if (i2c_write_data(chip, data, alen)) { 512 debug("i2c_read: error sending (0x%x)\n", 513 addr); 514 return 1; 515 } 516 } 517 if (i2c_read_data(chip, buffer + offset, 1)) { 518 debug("i2c_read: error reading (0x%x)\n", addr); 519 return 1; 520 } 521 } 522 523 return 0; 524 } 525 526 /* Write bytes */ 527 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) 528 { 529 uint offset; 530 int i; 531 532 debug("i2c_write: chip=0x%x, addr=0x%x, len=0x%x\n", 533 chip, addr, len); 534 if (!i2c_addr_ok(addr, alen)) { 535 debug("i2c_write: Bad address %x.%d.\n", addr, alen); 536 return 1; 537 } 538 for (offset = 0; offset < len; offset++) { 539 uchar data[alen + 1]; 540 for (i = 0; i < alen; i++) 541 data[alen - i - 1] = (addr + offset) >> (8 * i); 542 data[alen] = buffer[offset]; 543 if (i2c_write_data(chip, data, alen + 1)) { 544 debug("i2c_write: error sending (0x%x)\n", addr); 545 return 1; 546 } 547 } 548 549 return 0; 550 } 551 552 #if defined(CONFIG_I2C_MULTI_BUS) 553 /* 554 * Functions for multiple I2C bus handling 555 */ 556 unsigned int i2c_get_bus_num(void) 557 { 558 return i2c_bus_num; 559 } 560 561 int i2c_set_bus_num(unsigned int bus) 562 { 563 if (bus >= TEGRA_I2C_NUM_CONTROLLERS || !i2c_controllers[bus].inited) 564 return -1; 565 i2c_bus_num = bus; 566 567 return 0; 568 } 569 #endif 570