1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Synopsys DesignWare I2C adapter driver (master only). 4 * 5 * Based on the TI DAVINCI I2C adapter driver. 6 * 7 * Copyright (C) 2006 Texas Instruments. 8 * Copyright (C) 2007 MontaVista Software Inc. 9 * Copyright (C) 2009 Provigent Ltd. 10 */ 11 #include <linux/delay.h> 12 #include <linux/err.h> 13 #include <linux/errno.h> 14 #include <linux/export.h> 15 #include <linux/gpio/consumer.h> 16 #include <linux/i2c.h> 17 #include <linux/interrupt.h> 18 #include <linux/io.h> 19 #include <linux/module.h> 20 #include <linux/pinctrl/consumer.h> 21 #include <linux/pm_runtime.h> 22 #include <linux/regmap.h> 23 #include <linux/reset.h> 24 25 #include "i2c-designware-core.h" 26 27 #define AMD_TIMEOUT_MIN_US 25 28 #define AMD_TIMEOUT_MAX_US 250 29 #define AMD_MASTERCFG_MASK GENMASK(15, 0) 30 31 static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev) 32 { 33 /* Configure Tx/Rx FIFO threshold levels */ 34 regmap_write(dev->map, DW_IC_TX_TL, dev->tx_fifo_depth / 2); 35 regmap_write(dev->map, DW_IC_RX_TL, 0); 36 37 /* Configure the I2C master */ 38 regmap_write(dev->map, DW_IC_CON, dev->master_cfg); 39 } 40 41 static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) 42 { 43 unsigned int comp_param1; 44 u32 sda_falling_time, scl_falling_time; 45 struct i2c_timings *t = &dev->timings; 46 const char *fp_str = ""; 47 u32 ic_clk; 48 int ret; 49 50 ret = i2c_dw_acquire_lock(dev); 51 if (ret) 52 return ret; 53 54 ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &comp_param1); 55 i2c_dw_release_lock(dev); 56 if (ret) 57 return ret; 58 59 /* Set standard and fast speed dividers for high/low periods */ 60 sda_falling_time = t->sda_fall_ns ?: 300; /* ns */ 61 scl_falling_time = t->scl_fall_ns ?: 300; /* ns */ 62 63 /* Calculate SCL timing parameters for standard mode if not set */ 64 if (!dev->ss_hcnt || !dev->ss_lcnt) { 65 ic_clk = i2c_dw_clk_rate(dev); 66 dev->ss_hcnt = 67 i2c_dw_scl_hcnt(ic_clk, 68 4000, /* tHD;STA = tHIGH = 4.0 us */ 69 sda_falling_time, 70 0, /* 0: DW default, 1: Ideal */ 71 0); /* No offset */ 72 dev->ss_lcnt = 73 i2c_dw_scl_lcnt(ic_clk, 74 4700, /* tLOW = 4.7 us */ 75 scl_falling_time, 76 0); /* No offset */ 77 } 78 dev_dbg(dev->dev, "Standard Mode HCNT:LCNT = %d:%d\n", 79 dev->ss_hcnt, dev->ss_lcnt); 80 81 /* 82 * Set SCL timing parameters for fast mode or fast mode plus. Only 83 * difference is the timing parameter values since the registers are 84 * the same. 85 */ 86 if (t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ) { 87 /* 88 * Check are Fast Mode Plus parameters available. Calculate 89 * SCL timing parameters for Fast Mode Plus if not set. 90 */ 91 if (dev->fp_hcnt && dev->fp_lcnt) { 92 dev->fs_hcnt = dev->fp_hcnt; 93 dev->fs_lcnt = dev->fp_lcnt; 94 } else { 95 ic_clk = i2c_dw_clk_rate(dev); 96 dev->fs_hcnt = 97 i2c_dw_scl_hcnt(ic_clk, 98 260, /* tHIGH = 260 ns */ 99 sda_falling_time, 100 0, /* DW default */ 101 0); /* No offset */ 102 dev->fs_lcnt = 103 i2c_dw_scl_lcnt(ic_clk, 104 500, /* tLOW = 500 ns */ 105 scl_falling_time, 106 0); /* No offset */ 107 } 108 fp_str = " Plus"; 109 } 110 /* 111 * Calculate SCL timing parameters for fast mode if not set. They are 112 * needed also in high speed mode. 113 */ 114 if (!dev->fs_hcnt || !dev->fs_lcnt) { 115 ic_clk = i2c_dw_clk_rate(dev); 116 dev->fs_hcnt = 117 i2c_dw_scl_hcnt(ic_clk, 118 600, /* tHD;STA = tHIGH = 0.6 us */ 119 sda_falling_time, 120 0, /* 0: DW default, 1: Ideal */ 121 0); /* No offset */ 122 dev->fs_lcnt = 123 i2c_dw_scl_lcnt(ic_clk, 124 1300, /* tLOW = 1.3 us */ 125 scl_falling_time, 126 0); /* No offset */ 127 } 128 dev_dbg(dev->dev, "Fast Mode%s HCNT:LCNT = %d:%d\n", 129 fp_str, dev->fs_hcnt, dev->fs_lcnt); 130 131 /* Check is high speed possible and fall back to fast mode if not */ 132 if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) == 133 DW_IC_CON_SPEED_HIGH) { 134 if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK) 135 != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) { 136 dev_err(dev->dev, "High Speed not supported!\n"); 137 t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ; 138 dev->master_cfg &= ~DW_IC_CON_SPEED_MASK; 139 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 140 dev->hs_hcnt = 0; 141 dev->hs_lcnt = 0; 142 } else if (!dev->hs_hcnt || !dev->hs_lcnt) { 143 ic_clk = i2c_dw_clk_rate(dev); 144 dev->hs_hcnt = 145 i2c_dw_scl_hcnt(ic_clk, 146 160, /* tHIGH = 160 ns */ 147 sda_falling_time, 148 0, /* DW default */ 149 0); /* No offset */ 150 dev->hs_lcnt = 151 i2c_dw_scl_lcnt(ic_clk, 152 320, /* tLOW = 320 ns */ 153 scl_falling_time, 154 0); /* No offset */ 155 } 156 dev_dbg(dev->dev, "High Speed Mode HCNT:LCNT = %d:%d\n", 157 dev->hs_hcnt, dev->hs_lcnt); 158 } 159 160 ret = i2c_dw_set_sda_hold(dev); 161 if (ret) 162 return ret; 163 164 dev_dbg(dev->dev, "Bus speed: %s\n", i2c_freq_mode_string(t->bus_freq_hz)); 165 return 0; 166 } 167 168 /** 169 * i2c_dw_init_master() - Initialize the designware I2C master hardware 170 * @dev: device private data 171 * 172 * This functions configures and enables the I2C master. 173 * This function is called during I2C init function, and in case of timeout at 174 * run time. 175 */ 176 static int i2c_dw_init_master(struct dw_i2c_dev *dev) 177 { 178 int ret; 179 180 ret = i2c_dw_acquire_lock(dev); 181 if (ret) 182 return ret; 183 184 /* Disable the adapter */ 185 __i2c_dw_disable(dev); 186 187 /* Write standard speed timing parameters */ 188 regmap_write(dev->map, DW_IC_SS_SCL_HCNT, dev->ss_hcnt); 189 regmap_write(dev->map, DW_IC_SS_SCL_LCNT, dev->ss_lcnt); 190 191 /* Write fast mode/fast mode plus timing parameters */ 192 regmap_write(dev->map, DW_IC_FS_SCL_HCNT, dev->fs_hcnt); 193 regmap_write(dev->map, DW_IC_FS_SCL_LCNT, dev->fs_lcnt); 194 195 /* Write high speed timing parameters if supported */ 196 if (dev->hs_hcnt && dev->hs_lcnt) { 197 regmap_write(dev->map, DW_IC_HS_SCL_HCNT, dev->hs_hcnt); 198 regmap_write(dev->map, DW_IC_HS_SCL_LCNT, dev->hs_lcnt); 199 } 200 201 /* Write SDA hold time if supported */ 202 if (dev->sda_hold_time) 203 regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time); 204 205 i2c_dw_configure_fifo_master(dev); 206 i2c_dw_release_lock(dev); 207 208 return 0; 209 } 210 211 static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) 212 { 213 struct i2c_msg *msgs = dev->msgs; 214 u32 ic_con = 0, ic_tar = 0; 215 unsigned int dummy; 216 217 /* Disable the adapter */ 218 __i2c_dw_disable(dev); 219 220 /* If the slave address is ten bit address, enable 10BITADDR */ 221 if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) { 222 ic_con = DW_IC_CON_10BITADDR_MASTER; 223 /* 224 * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing 225 * mode has to be enabled via bit 12 of IC_TAR register. 226 * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be 227 * detected from registers. 228 */ 229 ic_tar = DW_IC_TAR_10BITADDR_MASTER; 230 } 231 232 regmap_update_bits(dev->map, DW_IC_CON, DW_IC_CON_10BITADDR_MASTER, 233 ic_con); 234 235 /* 236 * Set the slave (target) address and enable 10-bit addressing mode 237 * if applicable. 238 */ 239 regmap_write(dev->map, DW_IC_TAR, 240 msgs[dev->msg_write_idx].addr | ic_tar); 241 242 /* Enforce disabled interrupts (due to HW issues) */ 243 __i2c_dw_write_intr_mask(dev, 0); 244 245 /* Enable the adapter */ 246 __i2c_dw_enable(dev); 247 248 /* Dummy read to avoid the register getting stuck on Bay Trail */ 249 regmap_read(dev->map, DW_IC_ENABLE_STATUS, &dummy); 250 251 /* Clear and enable interrupts */ 252 regmap_read(dev->map, DW_IC_CLR_INTR, &dummy); 253 __i2c_dw_write_intr_mask(dev, DW_IC_INTR_MASTER_MASK); 254 } 255 256 static int i2c_dw_check_stopbit(struct dw_i2c_dev *dev) 257 { 258 u32 val; 259 int ret; 260 261 ret = regmap_read_poll_timeout(dev->map, DW_IC_INTR_STAT, val, 262 !(val & DW_IC_INTR_STOP_DET), 263 1100, 20000); 264 if (ret) 265 dev_err(dev->dev, "i2c timeout error %d\n", ret); 266 267 return ret; 268 } 269 270 static int i2c_dw_status(struct dw_i2c_dev *dev) 271 { 272 int status; 273 274 status = i2c_dw_wait_bus_not_busy(dev); 275 if (status) 276 return status; 277 278 return i2c_dw_check_stopbit(dev); 279 } 280 281 /* 282 * Initiate and continue master read/write transaction with polling 283 * based transfer routine afterward write messages into the Tx buffer. 284 */ 285 static int amd_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs, int num_msgs) 286 { 287 struct dw_i2c_dev *dev = i2c_get_adapdata(adap); 288 int msg_wrt_idx, msg_itr_lmt, buf_len, data_idx; 289 int cmd = 0, status; 290 u8 *tx_buf; 291 unsigned int val; 292 293 /* 294 * In order to enable the interrupt for UCSI i.e. AMD NAVI GPU card, 295 * it is mandatory to set the right value in specific register 296 * (offset:0x474) as per the hardware IP specification. 297 */ 298 regmap_write(dev->map, AMD_UCSI_INTR_REG, AMD_UCSI_INTR_EN); 299 300 dev->msgs = msgs; 301 dev->msgs_num = num_msgs; 302 i2c_dw_xfer_init(dev); 303 304 /* Initiate messages read/write transaction */ 305 for (msg_wrt_idx = 0; msg_wrt_idx < num_msgs; msg_wrt_idx++) { 306 tx_buf = msgs[msg_wrt_idx].buf; 307 buf_len = msgs[msg_wrt_idx].len; 308 309 if (!(msgs[msg_wrt_idx].flags & I2C_M_RD)) 310 regmap_write(dev->map, DW_IC_TX_TL, buf_len - 1); 311 /* 312 * Initiate the i2c read/write transaction of buffer length, 313 * and poll for bus busy status. For the last message transfer, 314 * update the command with stopbit enable. 315 */ 316 for (msg_itr_lmt = buf_len; msg_itr_lmt > 0; msg_itr_lmt--) { 317 if (msg_wrt_idx == num_msgs - 1 && msg_itr_lmt == 1) 318 cmd |= BIT(9); 319 320 if (msgs[msg_wrt_idx].flags & I2C_M_RD) { 321 /* Due to hardware bug, need to write the same command twice. */ 322 regmap_write(dev->map, DW_IC_DATA_CMD, 0x100); 323 regmap_write(dev->map, DW_IC_DATA_CMD, 0x100 | cmd); 324 if (cmd) { 325 regmap_write(dev->map, DW_IC_TX_TL, 2 * (buf_len - 1)); 326 regmap_write(dev->map, DW_IC_RX_TL, 2 * (buf_len - 1)); 327 /* 328 * Need to check the stop bit. However, it cannot be 329 * detected from the registers so we check it always 330 * when read/write the last byte. 331 */ 332 status = i2c_dw_status(dev); 333 if (status) 334 return status; 335 336 for (data_idx = 0; data_idx < buf_len; data_idx++) { 337 regmap_read(dev->map, DW_IC_DATA_CMD, &val); 338 tx_buf[data_idx] = val; 339 } 340 status = i2c_dw_check_stopbit(dev); 341 if (status) 342 return status; 343 } 344 } else { 345 regmap_write(dev->map, DW_IC_DATA_CMD, *tx_buf++ | cmd); 346 usleep_range(AMD_TIMEOUT_MIN_US, AMD_TIMEOUT_MAX_US); 347 } 348 } 349 status = i2c_dw_check_stopbit(dev); 350 if (status) 351 return status; 352 } 353 354 return 0; 355 } 356 357 /* 358 * Initiate (and continue) low level master read/write transaction. 359 * This function is only called from i2c_dw_isr, and pumping i2c_msg 360 * messages into the tx buffer. Even if the size of i2c_msg data is 361 * longer than the size of the tx buffer, it handles everything. 362 */ 363 static void 364 i2c_dw_xfer_msg(struct dw_i2c_dev *dev) 365 { 366 struct i2c_msg *msgs = dev->msgs; 367 u32 intr_mask; 368 int tx_limit, rx_limit; 369 u32 addr = msgs[dev->msg_write_idx].addr; 370 u32 buf_len = dev->tx_buf_len; 371 u8 *buf = dev->tx_buf; 372 bool need_restart = false; 373 unsigned int flr; 374 375 intr_mask = DW_IC_INTR_MASTER_MASK; 376 377 for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) { 378 u32 flags = msgs[dev->msg_write_idx].flags; 379 380 /* 381 * If target address has changed, we need to 382 * reprogram the target address in the I2C 383 * adapter when we are done with this transfer. 384 */ 385 if (msgs[dev->msg_write_idx].addr != addr) { 386 dev_err(dev->dev, 387 "%s: invalid target address\n", __func__); 388 dev->msg_err = -EINVAL; 389 break; 390 } 391 392 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) { 393 /* new i2c_msg */ 394 buf = msgs[dev->msg_write_idx].buf; 395 buf_len = msgs[dev->msg_write_idx].len; 396 397 /* If both IC_EMPTYFIFO_HOLD_MASTER_EN and 398 * IC_RESTART_EN are set, we must manually 399 * set restart bit between messages. 400 */ 401 if ((dev->master_cfg & DW_IC_CON_RESTART_EN) && 402 (dev->msg_write_idx > 0)) 403 need_restart = true; 404 } 405 406 regmap_read(dev->map, DW_IC_TXFLR, &flr); 407 tx_limit = dev->tx_fifo_depth - flr; 408 409 regmap_read(dev->map, DW_IC_RXFLR, &flr); 410 rx_limit = dev->rx_fifo_depth - flr; 411 412 while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { 413 u32 cmd = 0; 414 415 /* 416 * If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must 417 * manually set the stop bit. However, it cannot be 418 * detected from the registers so we set it always 419 * when writing/reading the last byte. 420 */ 421 422 /* 423 * i2c-core always sets the buffer length of 424 * I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will 425 * be adjusted when receiving the first byte. 426 * Thus we can't stop the transaction here. 427 */ 428 if (dev->msg_write_idx == dev->msgs_num - 1 && 429 buf_len == 1 && !(flags & I2C_M_RECV_LEN)) 430 cmd |= BIT(9); 431 432 if (need_restart) { 433 cmd |= BIT(10); 434 need_restart = false; 435 } 436 437 if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { 438 439 /* Avoid rx buffer overrun */ 440 if (dev->rx_outstanding >= dev->rx_fifo_depth) 441 break; 442 443 regmap_write(dev->map, DW_IC_DATA_CMD, 444 cmd | 0x100); 445 rx_limit--; 446 dev->rx_outstanding++; 447 } else { 448 regmap_write(dev->map, DW_IC_DATA_CMD, 449 cmd | *buf++); 450 } 451 tx_limit--; buf_len--; 452 } 453 454 dev->tx_buf = buf; 455 dev->tx_buf_len = buf_len; 456 457 /* 458 * Because we don't know the buffer length in the 459 * I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop the 460 * transaction here. Also disable the TX_EMPTY IRQ 461 * while waiting for the data length byte to avoid the 462 * bogus interrupts flood. 463 */ 464 if (flags & I2C_M_RECV_LEN) { 465 dev->status |= STATUS_WRITE_IN_PROGRESS; 466 intr_mask &= ~DW_IC_INTR_TX_EMPTY; 467 break; 468 } else if (buf_len > 0) { 469 /* more bytes to be written */ 470 dev->status |= STATUS_WRITE_IN_PROGRESS; 471 break; 472 } else 473 dev->status &= ~STATUS_WRITE_IN_PROGRESS; 474 } 475 476 /* 477 * If i2c_msg index search is completed, we don't need TX_EMPTY 478 * interrupt any more. 479 */ 480 if (dev->msg_write_idx == dev->msgs_num) 481 intr_mask &= ~DW_IC_INTR_TX_EMPTY; 482 483 if (dev->msg_err) 484 intr_mask = 0; 485 486 __i2c_dw_write_intr_mask(dev, intr_mask); 487 } 488 489 static u8 490 i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len) 491 { 492 struct i2c_msg *msgs = dev->msgs; 493 u32 flags = msgs[dev->msg_read_idx].flags; 494 unsigned int intr_mask; 495 496 /* 497 * Adjust the buffer length and mask the flag 498 * after receiving the first byte. 499 */ 500 len += (flags & I2C_CLIENT_PEC) ? 2 : 1; 501 dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding); 502 msgs[dev->msg_read_idx].len = len; 503 msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN; 504 505 /* 506 * Received buffer length, re-enable TX_EMPTY interrupt 507 * to resume the SMBUS transaction. 508 */ 509 __i2c_dw_read_intr_mask(dev, &intr_mask); 510 intr_mask |= DW_IC_INTR_TX_EMPTY; 511 __i2c_dw_write_intr_mask(dev, intr_mask); 512 513 return len; 514 } 515 516 static void 517 i2c_dw_read(struct dw_i2c_dev *dev) 518 { 519 struct i2c_msg *msgs = dev->msgs; 520 unsigned int rx_valid; 521 522 for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) { 523 unsigned int tmp; 524 u32 len; 525 u8 *buf; 526 527 if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD)) 528 continue; 529 530 if (!(dev->status & STATUS_READ_IN_PROGRESS)) { 531 len = msgs[dev->msg_read_idx].len; 532 buf = msgs[dev->msg_read_idx].buf; 533 } else { 534 len = dev->rx_buf_len; 535 buf = dev->rx_buf; 536 } 537 538 regmap_read(dev->map, DW_IC_RXFLR, &rx_valid); 539 540 for (; len > 0 && rx_valid > 0; len--, rx_valid--) { 541 u32 flags = msgs[dev->msg_read_idx].flags; 542 543 regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); 544 tmp &= DW_IC_DATA_CMD_DAT; 545 /* Ensure length byte is a valid value */ 546 if (flags & I2C_M_RECV_LEN) { 547 /* 548 * if IC_EMPTYFIFO_HOLD_MASTER_EN is set, which cannot be 549 * detected from the registers, the controller can be 550 * disabled if the STOP bit is set. But it is only set 551 * after receiving block data response length in 552 * I2C_FUNC_SMBUS_BLOCK_DATA case. That needs to read 553 * another byte with STOP bit set when the block data 554 * response length is invalid to complete the transaction. 555 */ 556 if (!tmp || tmp > I2C_SMBUS_BLOCK_MAX) 557 tmp = 1; 558 559 len = i2c_dw_recv_len(dev, tmp); 560 } 561 *buf++ = tmp; 562 dev->rx_outstanding--; 563 } 564 565 if (len > 0) { 566 dev->status |= STATUS_READ_IN_PROGRESS; 567 dev->rx_buf_len = len; 568 dev->rx_buf = buf; 569 return; 570 } else 571 dev->status &= ~STATUS_READ_IN_PROGRESS; 572 } 573 } 574 575 static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev) 576 { 577 unsigned int stat, dummy; 578 579 /* 580 * The IC_INTR_STAT register just indicates "enabled" interrupts. 581 * The unmasked raw version of interrupt status bits is available 582 * in the IC_RAW_INTR_STAT register. 583 * 584 * That is, 585 * stat = readl(IC_INTR_STAT); 586 * equals to, 587 * stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK); 588 * 589 * The raw version might be useful for debugging purposes. 590 */ 591 if (!(dev->flags & ACCESS_POLLING)) { 592 regmap_read(dev->map, DW_IC_INTR_STAT, &stat); 593 } else { 594 regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &stat); 595 stat &= dev->sw_mask; 596 } 597 598 /* 599 * Do not use the IC_CLR_INTR register to clear interrupts, or 600 * you'll miss some interrupts, triggered during the period from 601 * readl(IC_INTR_STAT) to readl(IC_CLR_INTR). 602 * 603 * Instead, use the separately-prepared IC_CLR_* registers. 604 */ 605 if (stat & DW_IC_INTR_RX_UNDER) 606 regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &dummy); 607 if (stat & DW_IC_INTR_RX_OVER) 608 regmap_read(dev->map, DW_IC_CLR_RX_OVER, &dummy); 609 if (stat & DW_IC_INTR_TX_OVER) 610 regmap_read(dev->map, DW_IC_CLR_TX_OVER, &dummy); 611 if (stat & DW_IC_INTR_RD_REQ) 612 regmap_read(dev->map, DW_IC_CLR_RD_REQ, &dummy); 613 if (stat & DW_IC_INTR_TX_ABRT) { 614 /* 615 * The IC_TX_ABRT_SOURCE register is cleared whenever 616 * the IC_CLR_TX_ABRT is read. Preserve it beforehand. 617 */ 618 regmap_read(dev->map, DW_IC_TX_ABRT_SOURCE, &dev->abort_source); 619 regmap_read(dev->map, DW_IC_CLR_TX_ABRT, &dummy); 620 } 621 if (stat & DW_IC_INTR_RX_DONE) 622 regmap_read(dev->map, DW_IC_CLR_RX_DONE, &dummy); 623 if (stat & DW_IC_INTR_ACTIVITY) 624 regmap_read(dev->map, DW_IC_CLR_ACTIVITY, &dummy); 625 if ((stat & DW_IC_INTR_STOP_DET) && 626 ((dev->rx_outstanding == 0) || (stat & DW_IC_INTR_RX_FULL))) 627 regmap_read(dev->map, DW_IC_CLR_STOP_DET, &dummy); 628 if (stat & DW_IC_INTR_START_DET) 629 regmap_read(dev->map, DW_IC_CLR_START_DET, &dummy); 630 if (stat & DW_IC_INTR_GEN_CALL) 631 regmap_read(dev->map, DW_IC_CLR_GEN_CALL, &dummy); 632 633 return stat; 634 } 635 636 static void i2c_dw_process_transfer(struct dw_i2c_dev *dev, unsigned int stat) 637 { 638 if (stat & DW_IC_INTR_TX_ABRT) { 639 dev->cmd_err |= DW_IC_ERR_TX_ABRT; 640 dev->status &= ~STATUS_MASK; 641 dev->rx_outstanding = 0; 642 643 /* 644 * Anytime TX_ABRT is set, the contents of the tx/rx 645 * buffers are flushed. Make sure to skip them. 646 */ 647 __i2c_dw_write_intr_mask(dev, 0); 648 goto tx_aborted; 649 } 650 651 if (stat & DW_IC_INTR_RX_FULL) 652 i2c_dw_read(dev); 653 654 if (stat & DW_IC_INTR_TX_EMPTY) 655 i2c_dw_xfer_msg(dev); 656 657 /* 658 * No need to modify or disable the interrupt mask here. 659 * i2c_dw_xfer_msg() will take care of it according to 660 * the current transmit status. 661 */ 662 663 tx_aborted: 664 if (((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err) && 665 (dev->rx_outstanding == 0)) 666 complete(&dev->cmd_complete); 667 else if (unlikely(dev->flags & ACCESS_INTR_MASK)) { 668 /* Workaround to trigger pending interrupt */ 669 __i2c_dw_read_intr_mask(dev, &stat); 670 __i2c_dw_write_intr_mask(dev, 0); 671 __i2c_dw_write_intr_mask(dev, stat); 672 } 673 } 674 675 /* 676 * Interrupt service routine. This gets called whenever an I2C master interrupt 677 * occurs. 678 */ 679 static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) 680 { 681 struct dw_i2c_dev *dev = dev_id; 682 unsigned int stat, enabled; 683 684 regmap_read(dev->map, DW_IC_ENABLE, &enabled); 685 regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &stat); 686 if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY)) 687 return IRQ_NONE; 688 if (pm_runtime_suspended(dev->dev) || stat == GENMASK(31, 0)) 689 return IRQ_NONE; 690 dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat); 691 692 stat = i2c_dw_read_clear_intrbits(dev); 693 694 if (!(dev->status & STATUS_ACTIVE)) { 695 /* 696 * Unexpected interrupt in driver point of view. State 697 * variables are either unset or stale so acknowledge and 698 * disable interrupts for suppressing further interrupts if 699 * interrupt really came from this HW (E.g. firmware has left 700 * the HW active). 701 */ 702 __i2c_dw_write_intr_mask(dev, 0); 703 return IRQ_HANDLED; 704 } 705 706 i2c_dw_process_transfer(dev, stat); 707 708 return IRQ_HANDLED; 709 } 710 711 static int i2c_dw_wait_transfer(struct dw_i2c_dev *dev) 712 { 713 unsigned long timeout = dev->adapter.timeout; 714 unsigned int stat; 715 int ret; 716 717 if (!(dev->flags & ACCESS_POLLING)) { 718 ret = wait_for_completion_timeout(&dev->cmd_complete, timeout); 719 } else { 720 timeout += jiffies; 721 do { 722 ret = try_wait_for_completion(&dev->cmd_complete); 723 if (ret) 724 break; 725 726 stat = i2c_dw_read_clear_intrbits(dev); 727 if (stat) 728 i2c_dw_process_transfer(dev, stat); 729 else 730 /* Try save some power */ 731 usleep_range(3, 25); 732 } while (time_before(jiffies, timeout)); 733 } 734 735 return ret ? 0 : -ETIMEDOUT; 736 } 737 738 /* 739 * Prepare controller for a transaction and call i2c_dw_xfer_msg. 740 */ 741 static int 742 i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 743 { 744 struct dw_i2c_dev *dev = i2c_get_adapdata(adap); 745 int ret; 746 747 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); 748 749 pm_runtime_get_sync(dev->dev); 750 751 switch (dev->flags & MODEL_MASK) { 752 case MODEL_AMD_NAVI_GPU: 753 ret = amd_i2c_dw_xfer_quirk(adap, msgs, num); 754 goto done_nolock; 755 default: 756 break; 757 } 758 759 reinit_completion(&dev->cmd_complete); 760 dev->msgs = msgs; 761 dev->msgs_num = num; 762 dev->cmd_err = 0; 763 dev->msg_write_idx = 0; 764 dev->msg_read_idx = 0; 765 dev->msg_err = 0; 766 dev->status = 0; 767 dev->abort_source = 0; 768 dev->rx_outstanding = 0; 769 770 ret = i2c_dw_acquire_lock(dev); 771 if (ret) 772 goto done_nolock; 773 774 ret = i2c_dw_wait_bus_not_busy(dev); 775 if (ret < 0) 776 goto done; 777 778 /* Start the transfers */ 779 i2c_dw_xfer_init(dev); 780 781 /* Wait for tx to complete */ 782 ret = i2c_dw_wait_transfer(dev); 783 if (ret) { 784 dev_err(dev->dev, "controller timed out\n"); 785 /* i2c_dw_init_master() implicitly disables the adapter */ 786 i2c_recover_bus(&dev->adapter); 787 i2c_dw_init_master(dev); 788 goto done; 789 } 790 791 /* 792 * We must disable the adapter before returning and signaling the end 793 * of the current transfer. Otherwise the hardware might continue 794 * generating interrupts which in turn causes a race condition with 795 * the following transfer. Needs some more investigation if the 796 * additional interrupts are a hardware bug or this driver doesn't 797 * handle them correctly yet. 798 */ 799 __i2c_dw_disable_nowait(dev); 800 801 if (dev->msg_err) { 802 ret = dev->msg_err; 803 goto done; 804 } 805 806 /* No error */ 807 if (likely(!dev->cmd_err && !dev->status)) { 808 ret = num; 809 goto done; 810 } 811 812 /* We have an error */ 813 if (dev->cmd_err == DW_IC_ERR_TX_ABRT) { 814 ret = i2c_dw_handle_tx_abort(dev); 815 goto done; 816 } 817 818 if (dev->status) 819 dev_err(dev->dev, 820 "transfer terminated early - interrupt latency too high?\n"); 821 822 ret = -EIO; 823 824 done: 825 i2c_dw_release_lock(dev); 826 827 done_nolock: 828 pm_runtime_mark_last_busy(dev->dev); 829 pm_runtime_put_autosuspend(dev->dev); 830 831 return ret; 832 } 833 834 static const struct i2c_algorithm i2c_dw_algo = { 835 .master_xfer = i2c_dw_xfer, 836 .functionality = i2c_dw_func, 837 }; 838 839 static const struct i2c_adapter_quirks i2c_dw_quirks = { 840 .flags = I2C_AQ_NO_ZERO_LEN, 841 }; 842 843 void i2c_dw_configure_master(struct dw_i2c_dev *dev) 844 { 845 struct i2c_timings *t = &dev->timings; 846 847 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 848 849 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 850 DW_IC_CON_RESTART_EN; 851 852 dev->mode = DW_IC_MASTER; 853 854 switch (t->bus_freq_hz) { 855 case I2C_MAX_STANDARD_MODE_FREQ: 856 dev->master_cfg |= DW_IC_CON_SPEED_STD; 857 break; 858 case I2C_MAX_HIGH_SPEED_MODE_FREQ: 859 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 860 break; 861 default: 862 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 863 } 864 } 865 EXPORT_SYMBOL_GPL(i2c_dw_configure_master); 866 867 static void i2c_dw_prepare_recovery(struct i2c_adapter *adap) 868 { 869 struct dw_i2c_dev *dev = i2c_get_adapdata(adap); 870 871 i2c_dw_disable(dev); 872 reset_control_assert(dev->rst); 873 i2c_dw_prepare_clk(dev, false); 874 } 875 876 static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap) 877 { 878 struct dw_i2c_dev *dev = i2c_get_adapdata(adap); 879 880 i2c_dw_prepare_clk(dev, true); 881 reset_control_deassert(dev->rst); 882 i2c_dw_init_master(dev); 883 } 884 885 static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev) 886 { 887 struct i2c_bus_recovery_info *rinfo = &dev->rinfo; 888 struct i2c_adapter *adap = &dev->adapter; 889 struct gpio_desc *gpio; 890 891 gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH); 892 if (IS_ERR_OR_NULL(gpio)) 893 return PTR_ERR_OR_ZERO(gpio); 894 895 rinfo->scl_gpiod = gpio; 896 897 gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN); 898 if (IS_ERR(gpio)) 899 return PTR_ERR(gpio); 900 rinfo->sda_gpiod = gpio; 901 902 rinfo->pinctrl = devm_pinctrl_get(dev->dev); 903 if (IS_ERR(rinfo->pinctrl)) { 904 if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER) 905 return PTR_ERR(rinfo->pinctrl); 906 907 rinfo->pinctrl = NULL; 908 dev_err(dev->dev, "getting pinctrl info failed: bus recovery might not work\n"); 909 } else if (!rinfo->pinctrl) { 910 dev_dbg(dev->dev, "pinctrl is disabled, bus recovery might not work\n"); 911 } 912 913 rinfo->recover_bus = i2c_generic_scl_recovery; 914 rinfo->prepare_recovery = i2c_dw_prepare_recovery; 915 rinfo->unprepare_recovery = i2c_dw_unprepare_recovery; 916 adap->bus_recovery_info = rinfo; 917 918 dev_info(dev->dev, "running with gpio recovery mode! scl%s", 919 rinfo->sda_gpiod ? ",sda" : ""); 920 921 return 0; 922 } 923 924 int i2c_dw_probe_master(struct dw_i2c_dev *dev) 925 { 926 struct i2c_adapter *adap = &dev->adapter; 927 unsigned long irq_flags; 928 unsigned int ic_con; 929 int ret; 930 931 init_completion(&dev->cmd_complete); 932 933 dev->init = i2c_dw_init_master; 934 dev->disable = i2c_dw_disable; 935 936 ret = i2c_dw_init_regmap(dev); 937 if (ret) 938 return ret; 939 940 ret = i2c_dw_set_timings_master(dev); 941 if (ret) 942 return ret; 943 944 ret = i2c_dw_set_fifo_size(dev); 945 if (ret) 946 return ret; 947 948 /* Lock the bus for accessing DW_IC_CON */ 949 ret = i2c_dw_acquire_lock(dev); 950 if (ret) 951 return ret; 952 953 /* 954 * On AMD platforms BIOS advertises the bus clear feature 955 * and enables the SCL/SDA stuck low. SMU FW does the 956 * bus recovery process. Driver should not ignore this BIOS 957 * advertisement of bus clear feature. 958 */ 959 ret = regmap_read(dev->map, DW_IC_CON, &ic_con); 960 i2c_dw_release_lock(dev); 961 if (ret) 962 return ret; 963 964 if (ic_con & DW_IC_CON_BUS_CLEAR_CTRL) 965 dev->master_cfg |= DW_IC_CON_BUS_CLEAR_CTRL; 966 967 ret = dev->init(dev); 968 if (ret) 969 return ret; 970 971 snprintf(adap->name, sizeof(adap->name), 972 "Synopsys DesignWare I2C adapter"); 973 adap->retries = 3; 974 adap->algo = &i2c_dw_algo; 975 adap->quirks = &i2c_dw_quirks; 976 adap->dev.parent = dev->dev; 977 i2c_set_adapdata(adap, dev); 978 979 if (dev->flags & ACCESS_NO_IRQ_SUSPEND) { 980 irq_flags = IRQF_NO_SUSPEND; 981 } else { 982 irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND; 983 } 984 985 ret = i2c_dw_acquire_lock(dev); 986 if (ret) 987 return ret; 988 989 __i2c_dw_write_intr_mask(dev, 0); 990 i2c_dw_release_lock(dev); 991 992 if (!(dev->flags & ACCESS_POLLING)) { 993 ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, 994 irq_flags, dev_name(dev->dev), dev); 995 if (ret) { 996 dev_err(dev->dev, "failure requesting irq %i: %d\n", 997 dev->irq, ret); 998 return ret; 999 } 1000 } 1001 1002 ret = i2c_dw_init_recovery_info(dev); 1003 if (ret) 1004 return ret; 1005 1006 /* 1007 * Increment PM usage count during adapter registration in order to 1008 * avoid possible spurious runtime suspend when adapter device is 1009 * registered to the device core and immediate resume in case bus has 1010 * registered I2C slaves that do I2C transfers in their probe. 1011 */ 1012 pm_runtime_get_noresume(dev->dev); 1013 ret = i2c_add_numbered_adapter(adap); 1014 if (ret) 1015 dev_err(dev->dev, "failure adding adapter: %d\n", ret); 1016 pm_runtime_put_noidle(dev->dev); 1017 1018 return ret; 1019 } 1020 EXPORT_SYMBOL_GPL(i2c_dw_probe_master); 1021 1022 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter"); 1023 MODULE_LICENSE("GPL"); 1024