1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * i2c-ocores.c: I2C bus driver for OpenCores I2C controller 4 * (https://opencores.org/project/i2c/overview) 5 * 6 * Peter Korsgaard <peter@korsgaard.com> 7 * 8 * Support for the GRLIB port of the controller by 9 * Andreas Larsson <andreas@gaisler.com> 10 */ 11 12 #include <linux/clk.h> 13 #include <linux/delay.h> 14 #include <linux/err.h> 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/errno.h> 18 #include <linux/platform_device.h> 19 #include <linux/i2c.h> 20 #include <linux/interrupt.h> 21 #include <linux/wait.h> 22 #include <linux/platform_data/i2c-ocores.h> 23 #include <linux/slab.h> 24 #include <linux/io.h> 25 #include <linux/log2.h> 26 #include <linux/spinlock.h> 27 #include <linux/jiffies.h> 28 29 /* 30 * 'process_lock' exists because ocores_process() and ocores_process_timeout() 31 * can't run in parallel. 32 */ 33 struct ocores_i2c { 34 void __iomem *base; 35 u32 reg_shift; 36 u32 reg_io_width; 37 unsigned long flags; 38 wait_queue_head_t wait; 39 struct i2c_adapter adap; 40 struct i2c_msg *msg; 41 int pos; 42 int nmsgs; 43 int state; /* see STATE_ */ 44 spinlock_t process_lock; 45 struct clk *clk; 46 int ip_clock_khz; 47 int bus_clock_khz; 48 void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value); 49 u8 (*getreg)(struct ocores_i2c *i2c, int reg); 50 }; 51 52 /* registers */ 53 #define OCI2C_PRELOW 0 54 #define OCI2C_PREHIGH 1 55 #define OCI2C_CONTROL 2 56 #define OCI2C_DATA 3 57 #define OCI2C_CMD 4 /* write only */ 58 #define OCI2C_STATUS 4 /* read only, same address as OCI2C_CMD */ 59 60 #define OCI2C_CTRL_IEN 0x40 61 #define OCI2C_CTRL_EN 0x80 62 63 #define OCI2C_CMD_START 0x91 64 #define OCI2C_CMD_STOP 0x41 65 #define OCI2C_CMD_READ 0x21 66 #define OCI2C_CMD_WRITE 0x11 67 #define OCI2C_CMD_READ_ACK 0x21 68 #define OCI2C_CMD_READ_NACK 0x29 69 #define OCI2C_CMD_IACK 0x01 70 71 #define OCI2C_STAT_IF 0x01 72 #define OCI2C_STAT_TIP 0x02 73 #define OCI2C_STAT_ARBLOST 0x20 74 #define OCI2C_STAT_BUSY 0x40 75 #define OCI2C_STAT_NACK 0x80 76 77 #define STATE_DONE 0 78 #define STATE_START 1 79 #define STATE_WRITE 2 80 #define STATE_READ 3 81 #define STATE_ERROR 4 82 83 #define TYPE_OCORES 0 84 #define TYPE_GRLIB 1 85 86 #define OCORES_FLAG_BROKEN_IRQ BIT(1) /* Broken IRQ for FU540-C000 SoC */ 87 88 static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value) 89 { 90 iowrite8(value, i2c->base + (reg << i2c->reg_shift)); 91 } 92 93 static void oc_setreg_16(struct ocores_i2c *i2c, int reg, u8 value) 94 { 95 iowrite16(value, i2c->base + (reg << i2c->reg_shift)); 96 } 97 98 static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value) 99 { 100 iowrite32(value, i2c->base + (reg << i2c->reg_shift)); 101 } 102 103 static void oc_setreg_16be(struct ocores_i2c *i2c, int reg, u8 value) 104 { 105 iowrite16be(value, i2c->base + (reg << i2c->reg_shift)); 106 } 107 108 static void oc_setreg_32be(struct ocores_i2c *i2c, int reg, u8 value) 109 { 110 iowrite32be(value, i2c->base + (reg << i2c->reg_shift)); 111 } 112 113 static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg) 114 { 115 return ioread8(i2c->base + (reg << i2c->reg_shift)); 116 } 117 118 static inline u8 oc_getreg_16(struct ocores_i2c *i2c, int reg) 119 { 120 return ioread16(i2c->base + (reg << i2c->reg_shift)); 121 } 122 123 static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg) 124 { 125 return ioread32(i2c->base + (reg << i2c->reg_shift)); 126 } 127 128 static inline u8 oc_getreg_16be(struct ocores_i2c *i2c, int reg) 129 { 130 return ioread16be(i2c->base + (reg << i2c->reg_shift)); 131 } 132 133 static inline u8 oc_getreg_32be(struct ocores_i2c *i2c, int reg) 134 { 135 return ioread32be(i2c->base + (reg << i2c->reg_shift)); 136 } 137 138 static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) 139 { 140 i2c->setreg(i2c, reg, value); 141 } 142 143 static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) 144 { 145 return i2c->getreg(i2c, reg); 146 } 147 148 static void ocores_process(struct ocores_i2c *i2c, u8 stat) 149 { 150 struct i2c_msg *msg = i2c->msg; 151 unsigned long flags; 152 153 /* 154 * If we spin here is because we are in timeout, so we are going 155 * to be in STATE_ERROR. See ocores_process_timeout() 156 */ 157 spin_lock_irqsave(&i2c->process_lock, flags); 158 159 if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) { 160 /* stop has been sent */ 161 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); 162 wake_up(&i2c->wait); 163 goto out; 164 } 165 166 /* error? */ 167 if (stat & OCI2C_STAT_ARBLOST) { 168 i2c->state = STATE_ERROR; 169 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); 170 goto out; 171 } 172 173 if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) { 174 i2c->state = 175 (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE; 176 177 if (stat & OCI2C_STAT_NACK) { 178 i2c->state = STATE_ERROR; 179 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); 180 goto out; 181 } 182 } else { 183 msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA); 184 } 185 186 /* end of msg? */ 187 if (i2c->pos == msg->len) { 188 i2c->nmsgs--; 189 i2c->msg++; 190 i2c->pos = 0; 191 msg = i2c->msg; 192 193 if (i2c->nmsgs) { /* end? */ 194 /* send start? */ 195 if (!(msg->flags & I2C_M_NOSTART)) { 196 u8 addr = i2c_8bit_addr_from_msg(msg); 197 198 i2c->state = STATE_START; 199 200 oc_setreg(i2c, OCI2C_DATA, addr); 201 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); 202 goto out; 203 } 204 i2c->state = (msg->flags & I2C_M_RD) 205 ? STATE_READ : STATE_WRITE; 206 } else { 207 i2c->state = STATE_DONE; 208 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); 209 goto out; 210 } 211 } 212 213 if (i2c->state == STATE_READ) { 214 oc_setreg(i2c, OCI2C_CMD, i2c->pos == (msg->len-1) ? 215 OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK); 216 } else { 217 oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]); 218 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_WRITE); 219 } 220 221 out: 222 spin_unlock_irqrestore(&i2c->process_lock, flags); 223 } 224 225 static irqreturn_t ocores_isr(int irq, void *dev_id) 226 { 227 struct ocores_i2c *i2c = dev_id; 228 u8 stat = oc_getreg(i2c, OCI2C_STATUS); 229 230 if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) { 231 if ((stat & OCI2C_STAT_IF) && !(stat & OCI2C_STAT_BUSY)) 232 return IRQ_NONE; 233 } else if (!(stat & OCI2C_STAT_IF)) { 234 return IRQ_NONE; 235 } 236 ocores_process(i2c, stat); 237 238 return IRQ_HANDLED; 239 } 240 241 /** 242 * ocores_process_timeout() - Process timeout event 243 * @i2c: ocores I2C device instance 244 */ 245 static void ocores_process_timeout(struct ocores_i2c *i2c) 246 { 247 unsigned long flags; 248 249 spin_lock_irqsave(&i2c->process_lock, flags); 250 i2c->state = STATE_ERROR; 251 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); 252 spin_unlock_irqrestore(&i2c->process_lock, flags); 253 } 254 255 /** 256 * ocores_wait() - Wait until something change in a given register 257 * @i2c: ocores I2C device instance 258 * @reg: register to query 259 * @mask: bitmask to apply on register value 260 * @val: expected result 261 * @timeout: timeout in jiffies 262 * 263 * Timeout is necessary to avoid to stay here forever when the chip 264 * does not answer correctly. 265 * 266 * Return: 0 on success, -ETIMEDOUT on timeout 267 */ 268 static int ocores_wait(struct ocores_i2c *i2c, 269 int reg, u8 mask, u8 val, 270 const unsigned long timeout) 271 { 272 unsigned long j; 273 274 j = jiffies + timeout; 275 while (1) { 276 u8 status = oc_getreg(i2c, reg); 277 278 if ((status & mask) == val) 279 break; 280 281 if (time_after(jiffies, j)) 282 return -ETIMEDOUT; 283 } 284 return 0; 285 } 286 287 /** 288 * ocores_poll_wait() - Wait until is possible to process some data 289 * @i2c: ocores I2C device instance 290 * 291 * Used when the device is in polling mode (interrupts disabled). 292 * 293 * Return: 0 on success, -ETIMEDOUT on timeout 294 */ 295 static int ocores_poll_wait(struct ocores_i2c *i2c) 296 { 297 u8 mask; 298 int err; 299 300 if (i2c->state == STATE_DONE || i2c->state == STATE_ERROR) { 301 /* transfer is over */ 302 mask = OCI2C_STAT_BUSY; 303 } else { 304 /* on going transfer */ 305 mask = OCI2C_STAT_TIP; 306 /* 307 * We wait for the data to be transferred (8bit), 308 * then we start polling on the ACK/NACK bit 309 */ 310 udelay((8 * 1000) / i2c->bus_clock_khz); 311 } 312 313 /* 314 * once we are here we expect to get the expected result immediately 315 * so if after 1ms we timeout then something is broken. 316 */ 317 err = ocores_wait(i2c, OCI2C_STATUS, mask, 0, msecs_to_jiffies(1)); 318 if (err) 319 dev_warn(i2c->adap.dev.parent, 320 "%s: STATUS timeout, bit 0x%x did not clear in 1ms\n", 321 __func__, mask); 322 return err; 323 } 324 325 /** 326 * ocores_process_polling() - It handles an IRQ-less transfer 327 * @i2c: ocores I2C device instance 328 * 329 * Even if IRQ are disabled, the I2C OpenCore IP behavior is exactly the same 330 * (only that IRQ are not produced). This means that we can re-use entirely 331 * ocores_isr(), we just add our polling code around it. 332 * 333 * It can run in atomic context 334 * 335 * Return: 0 on success, -ETIMEDOUT on timeout 336 */ 337 static int ocores_process_polling(struct ocores_i2c *i2c) 338 { 339 irqreturn_t ret; 340 int err = 0; 341 342 while (1) { 343 err = ocores_poll_wait(i2c); 344 if (err) 345 break; /* timeout */ 346 347 ret = ocores_isr(-1, i2c); 348 if (ret == IRQ_NONE) 349 break; /* all messages have been transferred */ 350 else { 351 if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) 352 if (i2c->state == STATE_DONE) 353 break; 354 } 355 } 356 357 return err; 358 } 359 360 static int ocores_xfer_core(struct ocores_i2c *i2c, 361 struct i2c_msg *msgs, int num, 362 bool polling) 363 { 364 int ret = 0; 365 u8 ctrl; 366 367 ctrl = oc_getreg(i2c, OCI2C_CONTROL); 368 if (polling) 369 oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~OCI2C_CTRL_IEN); 370 else 371 oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN); 372 373 i2c->msg = msgs; 374 i2c->pos = 0; 375 i2c->nmsgs = num; 376 i2c->state = STATE_START; 377 378 oc_setreg(i2c, OCI2C_DATA, i2c_8bit_addr_from_msg(i2c->msg)); 379 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); 380 381 if (polling) { 382 ret = ocores_process_polling(i2c); 383 } else { 384 if (wait_event_timeout(i2c->wait, 385 (i2c->state == STATE_ERROR) || 386 (i2c->state == STATE_DONE), HZ) == 0) 387 ret = -ETIMEDOUT; 388 } 389 if (ret) { 390 ocores_process_timeout(i2c); 391 return ret; 392 } 393 394 return (i2c->state == STATE_DONE) ? num : -EIO; 395 } 396 397 static int ocores_xfer_polling(struct i2c_adapter *adap, 398 struct i2c_msg *msgs, int num) 399 { 400 return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, true); 401 } 402 403 static int ocores_xfer(struct i2c_adapter *adap, 404 struct i2c_msg *msgs, int num) 405 { 406 return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, false); 407 } 408 409 static int ocores_init(struct device *dev, struct ocores_i2c *i2c) 410 { 411 int prescale; 412 int diff; 413 u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); 414 415 /* make sure the device is disabled */ 416 ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN); 417 oc_setreg(i2c, OCI2C_CONTROL, ctrl); 418 419 prescale = (i2c->ip_clock_khz / (5 * i2c->bus_clock_khz)) - 1; 420 prescale = clamp(prescale, 0, 0xffff); 421 422 diff = i2c->ip_clock_khz / (5 * (prescale + 1)) - i2c->bus_clock_khz; 423 if (abs(diff) > i2c->bus_clock_khz / 10) { 424 dev_err(dev, 425 "Unsupported clock settings: core: %d KHz, bus: %d KHz\n", 426 i2c->ip_clock_khz, i2c->bus_clock_khz); 427 return -EINVAL; 428 } 429 430 oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff); 431 oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8); 432 433 /* Init the device */ 434 oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); 435 oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_EN); 436 437 return 0; 438 } 439 440 441 static u32 ocores_func(struct i2c_adapter *adap) 442 { 443 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 444 } 445 446 static struct i2c_algorithm ocores_algorithm = { 447 .master_xfer = ocores_xfer, 448 .master_xfer_atomic = ocores_xfer_polling, 449 .functionality = ocores_func, 450 }; 451 452 static const struct i2c_adapter ocores_adapter = { 453 .owner = THIS_MODULE, 454 .name = "i2c-ocores", 455 .class = I2C_CLASS_DEPRECATED, 456 .algo = &ocores_algorithm, 457 }; 458 459 static const struct of_device_id ocores_i2c_match[] = { 460 { 461 .compatible = "opencores,i2c-ocores", 462 .data = (void *)TYPE_OCORES, 463 }, 464 { 465 .compatible = "aeroflexgaisler,i2cmst", 466 .data = (void *)TYPE_GRLIB, 467 }, 468 { 469 .compatible = "sifive,fu540-c000-i2c", 470 }, 471 { 472 .compatible = "sifive,i2c0", 473 }, 474 {}, 475 }; 476 MODULE_DEVICE_TABLE(of, ocores_i2c_match); 477 478 #ifdef CONFIG_OF 479 /* 480 * Read and write functions for the GRLIB port of the controller. Registers are 481 * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one 482 * register. The subsequent registers have their offsets decreased accordingly. 483 */ 484 static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg) 485 { 486 u32 rd; 487 int rreg = reg; 488 489 if (reg != OCI2C_PRELOW) 490 rreg--; 491 rd = ioread32be(i2c->base + (rreg << i2c->reg_shift)); 492 if (reg == OCI2C_PREHIGH) 493 return (u8)(rd >> 8); 494 else 495 return (u8)rd; 496 } 497 498 static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value) 499 { 500 u32 curr, wr; 501 int rreg = reg; 502 503 if (reg != OCI2C_PRELOW) 504 rreg--; 505 if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) { 506 curr = ioread32be(i2c->base + (rreg << i2c->reg_shift)); 507 if (reg == OCI2C_PRELOW) 508 wr = (curr & 0xff00) | value; 509 else 510 wr = (((u32)value) << 8) | (curr & 0xff); 511 } else { 512 wr = value; 513 } 514 iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift)); 515 } 516 517 static int ocores_i2c_of_probe(struct platform_device *pdev, 518 struct ocores_i2c *i2c) 519 { 520 struct device_node *np = pdev->dev.of_node; 521 const struct of_device_id *match; 522 u32 val; 523 u32 clock_frequency; 524 bool clock_frequency_present; 525 526 if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) { 527 /* no 'reg-shift', check for deprecated 'regstep' */ 528 if (!of_property_read_u32(np, "regstep", &val)) { 529 if (!is_power_of_2(val)) { 530 dev_err(&pdev->dev, "invalid regstep %d\n", 531 val); 532 return -EINVAL; 533 } 534 i2c->reg_shift = ilog2(val); 535 dev_warn(&pdev->dev, 536 "regstep property deprecated, use reg-shift\n"); 537 } 538 } 539 540 clock_frequency_present = !of_property_read_u32(np, "clock-frequency", 541 &clock_frequency); 542 i2c->bus_clock_khz = 100; 543 544 i2c->clk = devm_clk_get_optional_enabled(&pdev->dev, NULL); 545 if (IS_ERR(i2c->clk)) 546 return dev_err_probe(&pdev->dev, PTR_ERR(i2c->clk), 547 "devm_clk_get_optional_enabled failed\n"); 548 549 i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000; 550 if (clock_frequency_present) 551 i2c->bus_clock_khz = clock_frequency / 1000; 552 if (i2c->ip_clock_khz == 0) { 553 if (of_property_read_u32(np, "opencores,ip-clock-frequency", 554 &val)) { 555 if (!clock_frequency_present) { 556 dev_err(&pdev->dev, 557 "Missing required parameter 'opencores,ip-clock-frequency'\n"); 558 return -ENODEV; 559 } 560 i2c->ip_clock_khz = clock_frequency / 1000; 561 dev_warn(&pdev->dev, 562 "Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n"); 563 } else { 564 i2c->ip_clock_khz = val / 1000; 565 if (clock_frequency_present) 566 i2c->bus_clock_khz = clock_frequency / 1000; 567 } 568 } 569 570 of_property_read_u32(pdev->dev.of_node, "reg-io-width", 571 &i2c->reg_io_width); 572 573 match = of_match_node(ocores_i2c_match, pdev->dev.of_node); 574 if (match && (long)match->data == TYPE_GRLIB) { 575 dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n"); 576 i2c->setreg = oc_setreg_grlib; 577 i2c->getreg = oc_getreg_grlib; 578 } 579 580 return 0; 581 } 582 #else 583 #define ocores_i2c_of_probe(pdev, i2c) -ENODEV 584 #endif 585 586 static int ocores_i2c_probe(struct platform_device *pdev) 587 { 588 struct ocores_i2c *i2c; 589 struct ocores_i2c_platform_data *pdata; 590 struct resource *res; 591 int irq; 592 int ret; 593 int i; 594 595 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); 596 if (!i2c) 597 return -ENOMEM; 598 599 spin_lock_init(&i2c->process_lock); 600 601 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 602 if (res) { 603 i2c->base = devm_ioremap_resource(&pdev->dev, res); 604 if (IS_ERR(i2c->base)) 605 return PTR_ERR(i2c->base); 606 } else { 607 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 608 if (!res) 609 return -EINVAL; 610 if (!devm_request_region(&pdev->dev, res->start, 611 resource_size(res), 612 pdev->name)) { 613 dev_err(&pdev->dev, "Can't get I/O resource.\n"); 614 return -EBUSY; 615 } 616 i2c->base = devm_ioport_map(&pdev->dev, res->start, 617 resource_size(res)); 618 if (!i2c->base) { 619 dev_err(&pdev->dev, "Can't map I/O resource.\n"); 620 return -EBUSY; 621 } 622 i2c->reg_io_width = 1; 623 } 624 625 pdata = dev_get_platdata(&pdev->dev); 626 if (pdata) { 627 i2c->reg_shift = pdata->reg_shift; 628 i2c->reg_io_width = pdata->reg_io_width; 629 i2c->ip_clock_khz = pdata->clock_khz; 630 if (pdata->bus_khz) 631 i2c->bus_clock_khz = pdata->bus_khz; 632 else 633 i2c->bus_clock_khz = 100; 634 } else { 635 ret = ocores_i2c_of_probe(pdev, i2c); 636 if (ret) 637 return ret; 638 } 639 640 if (i2c->reg_io_width == 0) 641 i2c->reg_io_width = 1; /* Set to default value */ 642 643 if (!i2c->setreg || !i2c->getreg) { 644 bool be = pdata ? pdata->big_endian : 645 of_device_is_big_endian(pdev->dev.of_node); 646 647 switch (i2c->reg_io_width) { 648 case 1: 649 i2c->setreg = oc_setreg_8; 650 i2c->getreg = oc_getreg_8; 651 break; 652 653 case 2: 654 i2c->setreg = be ? oc_setreg_16be : oc_setreg_16; 655 i2c->getreg = be ? oc_getreg_16be : oc_getreg_16; 656 break; 657 658 case 4: 659 i2c->setreg = be ? oc_setreg_32be : oc_setreg_32; 660 i2c->getreg = be ? oc_getreg_32be : oc_getreg_32; 661 break; 662 663 default: 664 dev_err(&pdev->dev, "Unsupported I/O width (%d)\n", 665 i2c->reg_io_width); 666 return -EINVAL; 667 } 668 } 669 670 init_waitqueue_head(&i2c->wait); 671 672 irq = platform_get_irq_optional(pdev, 0); 673 /* 674 * Since the SoC does have an interrupt, its DT has an interrupt 675 * property - But this should be bypassed as the IRQ logic in this 676 * SoC is broken. 677 */ 678 if (of_device_is_compatible(pdev->dev.of_node, 679 "sifive,fu540-c000-i2c")) { 680 i2c->flags |= OCORES_FLAG_BROKEN_IRQ; 681 irq = -ENXIO; 682 } 683 684 if (irq == -ENXIO) { 685 ocores_algorithm.master_xfer = ocores_xfer_polling; 686 } else { 687 if (irq < 0) 688 return irq; 689 } 690 691 if (ocores_algorithm.master_xfer != ocores_xfer_polling) { 692 ret = devm_request_any_context_irq(&pdev->dev, irq, 693 ocores_isr, 0, 694 pdev->name, i2c); 695 if (ret) { 696 dev_err(&pdev->dev, "Cannot claim IRQ\n"); 697 return ret; 698 } 699 } 700 701 ret = ocores_init(&pdev->dev, i2c); 702 if (ret) 703 return ret; 704 705 /* hook up driver to tree */ 706 platform_set_drvdata(pdev, i2c); 707 i2c->adap = ocores_adapter; 708 i2c_set_adapdata(&i2c->adap, i2c); 709 i2c->adap.dev.parent = &pdev->dev; 710 i2c->adap.dev.of_node = pdev->dev.of_node; 711 712 /* add i2c adapter to i2c tree */ 713 ret = i2c_add_adapter(&i2c->adap); 714 if (ret) 715 return ret; 716 717 /* add in known devices to the bus */ 718 if (pdata) { 719 for (i = 0; i < pdata->num_devices; i++) 720 i2c_new_client_device(&i2c->adap, pdata->devices + i); 721 } 722 723 return 0; 724 } 725 726 static void ocores_i2c_remove(struct platform_device *pdev) 727 { 728 struct ocores_i2c *i2c = platform_get_drvdata(pdev); 729 u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); 730 731 /* disable i2c logic */ 732 ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN); 733 oc_setreg(i2c, OCI2C_CONTROL, ctrl); 734 735 /* remove adapter & data */ 736 i2c_del_adapter(&i2c->adap); 737 } 738 739 static int ocores_i2c_suspend(struct device *dev) 740 { 741 struct ocores_i2c *i2c = dev_get_drvdata(dev); 742 u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); 743 744 /* make sure the device is disabled */ 745 ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN); 746 oc_setreg(i2c, OCI2C_CONTROL, ctrl); 747 748 clk_disable_unprepare(i2c->clk); 749 return 0; 750 } 751 752 static int ocores_i2c_resume(struct device *dev) 753 { 754 struct ocores_i2c *i2c = dev_get_drvdata(dev); 755 unsigned long rate; 756 int ret; 757 758 ret = clk_prepare_enable(i2c->clk); 759 if (ret) 760 return dev_err_probe(dev, ret, "clk_prepare_enable failed\n"); 761 rate = clk_get_rate(i2c->clk) / 1000; 762 if (rate) 763 i2c->ip_clock_khz = rate; 764 return ocores_init(dev, i2c); 765 } 766 767 static DEFINE_NOIRQ_DEV_PM_OPS(ocores_i2c_pm, 768 ocores_i2c_suspend, ocores_i2c_resume); 769 770 static struct platform_driver ocores_i2c_driver = { 771 .probe = ocores_i2c_probe, 772 .remove_new = ocores_i2c_remove, 773 .driver = { 774 .name = "ocores-i2c", 775 .of_match_table = ocores_i2c_match, 776 .pm = pm_sleep_ptr(&ocores_i2c_pm), 777 }, 778 }; 779 780 module_platform_driver(ocores_i2c_driver); 781 782 MODULE_AUTHOR("Peter Korsgaard <peter@korsgaard.com>"); 783 MODULE_DESCRIPTION("OpenCores I2C bus driver"); 784 MODULE_LICENSE("GPL"); 785 MODULE_ALIAS("platform:ocores-i2c"); 786