Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 | // SPDX-License-Identifier: GPL-2.0-only /* ------------------------------------------------------------------------- */ /* i2c-iop3xx.c i2c driver algorithms for Intel XScale IOP3xx & IXP46x */ /* ------------------------------------------------------------------------- */ /* Copyright (C) 2003 Peter Milne, D-TACQ Solutions Ltd * <Peter dot Milne at D hyphen TACQ dot com> * * With acknowledgements to i2c-algo-ibm_ocp.c by * Ian DaSilva, MontaVista Software, Inc. idasilva@mvista.com * * And i2c-algo-pcf.c, which was created by Simon G. Vogl and Hans Berglund: * * Copyright (C) 1995-1997 Simon G. Vogl, 1998-2000 Hans Berglund * * And which acknowledged Kyösti Mälkki <kmalkki@cc.hut.fi>, * Frodo Looijaard <frodol@dds.nl>, Martin Bailey<mbailey@littlefeet-inc.com> * * Major cleanup by Deepak Saxena <dsaxena@plexity.net>, 01/2005: * * - Use driver model to pass per-chip info instead of hardcoding and #ifdefs * - Use ioremap/__raw_readl/__raw_writel instead of direct dereference * - Make it work with IXP46x chips * - Cleanup function names, coding style, etc * * - writing to slave address causes latchup on iop331. * fix: driver refuses to address self. */ #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/slab.h> #include <linux/errno.h> #include <linux/platform_device.h> #include <linux/i2c.h> #include <linux/io.h> #include <linux/gpio/consumer.h> #include "i2c-iop3xx.h" /* global unit counter */ static int i2c_id; static inline unsigned char iic_cook_addr(struct i2c_msg *msg) { unsigned char addr; addr = i2c_8bit_addr_from_msg(msg); return addr; } static void iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap) { /* Follows devman 9.3 */ __raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET); __raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET); __raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET); } static void iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap) { u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE; /* * Every time unit enable is asserted, GPOD needs to be cleared * on IOP3XX to avoid data corruption on the bus. We use the * gpiod_set_raw_value() to make sure the 0 hits the hardware * GPOD register. These descriptors are only passed along to * the device if this is necessary. */ if (iop3xx_adap->gpio_scl) gpiod_set_raw_value(iop3xx_adap->gpio_scl, 0); if (iop3xx_adap->gpio_sda) gpiod_set_raw_value(iop3xx_adap->gpio_sda, 0); /* NB SR bits not same position as CR IE bits :-( */ iop3xx_adap->SR_enabled = IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD | IOP3XX_ISR_RXFULL | IOP3XX_ISR_TXEMPTY; cr |= IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE | IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE; __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); } static void iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap) { unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); cr &= ~(IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE | IOP3XX_ICR_MSTOP | IOP3XX_ICR_SCLEN); __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); } /* * NB: the handler has to clear the source of the interrupt! * Then it passes the SR flags of interest to BH via adap data */ static irqreturn_t iop3xx_i2c_irq_handler(int this_irq, void *dev_id) { struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id; u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET); if ((sr &= iop3xx_adap->SR_enabled)) { __raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET); iop3xx_adap->SR_received |= sr; wake_up_interruptible(&iop3xx_adap->waitq); } return IRQ_HANDLED; } /* check all error conditions, clear them , report most important */ static int iop3xx_i2c_error(u32 sr) { int rc = 0; if ((sr & IOP3XX_ISR_BERRD)) { if (!rc) rc = -I2C_ERR_BERR; } if ((sr & IOP3XX_ISR_ALD)) { if (!rc) rc = -I2C_ERR_ALD; } return rc; } static inline u32 iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap) { unsigned long flags; u32 sr; spin_lock_irqsave(&iop3xx_adap->lock, flags); sr = iop3xx_adap->SR_received; iop3xx_adap->SR_received = 0; spin_unlock_irqrestore(&iop3xx_adap->lock, flags); return sr; } /* * sleep until interrupted, then recover and analyse the SR * saved by handler */ typedef int (*compare_func)(unsigned test, unsigned mask); /* returns 1 on correct comparison */ static int iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap, unsigned flags, unsigned *status, compare_func compare) { unsigned sr = 0; int interrupted; int done; int rc = 0; do { interrupted = wait_event_interruptible_timeout ( iop3xx_adap->waitq, (done = compare(sr = iop3xx_i2c_get_srstat(iop3xx_adap), flags)), 1 * HZ ); if ((rc = iop3xx_i2c_error(sr)) < 0) { *status = sr; return rc; } else if (!interrupted) { *status = sr; return -ETIMEDOUT; } } while (!done); *status = sr; return 0; } /* * Concrete compare_funcs */ static int all_bits_clear(unsigned test, unsigned mask) { return (test & mask) == 0; } static int any_bits_set(unsigned test, unsigned mask) { return (test & mask) != 0; } static int iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status) { return iop3xx_i2c_wait_event( iop3xx_adap, IOP3XX_ISR_TXEMPTY | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD, status, any_bits_set); } static int iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status) { return iop3xx_i2c_wait_event( iop3xx_adap, IOP3XX_ISR_RXFULL | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD, status, any_bits_set); } static int iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status) { return iop3xx_i2c_wait_event( iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear); } static int iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap, struct i2c_msg *msg) { unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); int status; int rc; /* avoid writing to my slave address (hangs on 80331), * forbidden in Intel developer manual */ if (msg->addr == MYSAR) { return -EBUSY; } __raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET); cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK); cr |= IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE; __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status); return rc; } static int iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte, int stop) { unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); int status; int rc = 0; __raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET); cr &= ~IOP3XX_ICR_MSTART; if (stop) { cr |= IOP3XX_ICR_MSTOP; } else { cr &= ~IOP3XX_ICR_MSTOP; } cr |= IOP3XX_ICR_TBYTE; __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status); return rc; } static int iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char *byte, int stop) { unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); int status; int rc = 0; cr &= ~IOP3XX_ICR_MSTART; if (stop) { cr |= IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK; } else { cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK); } cr |= IOP3XX_ICR_TBYTE; __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status); *byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET); return rc; } static int iop3xx_i2c_writebytes(struct i2c_adapter *i2c_adap, const char *buf, int count) { struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; int ii; int rc = 0; for (ii = 0; rc == 0 && ii != count; ++ii) rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii == count-1); return rc; } static int iop3xx_i2c_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count) { struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; int ii; int rc = 0; for (ii = 0; rc == 0 && ii != count; ++ii) rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii == count-1); return rc; } /* * Description: This function implements combined transactions. Combined * transactions consist of combinations of reading and writing blocks of data. * FROM THE SAME ADDRESS * Each transfer (i.e. a read or a write) is separated by a repeated start * condition. */ static int iop3xx_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg *pmsg) { struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; int rc; rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg); if (rc < 0) { return rc; } if ((pmsg->flags&I2C_M_RD)) { return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len); } else { return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len); } } /* * master_xfer() - main read/write entry */ static int iop3xx_i2c_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) { struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; int im = 0; int ret = 0; int status; iop3xx_i2c_wait_idle(iop3xx_adap, &status); iop3xx_i2c_reset(iop3xx_adap); iop3xx_i2c_enable(iop3xx_adap); for (im = 0; ret == 0 && im != num; im++) { ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]); } iop3xx_i2c_transaction_cleanup(iop3xx_adap); if (ret) return ret; return im; } static u32 iop3xx_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static const struct i2c_algorithm iop3xx_i2c_algo = { .master_xfer = iop3xx_i2c_master_xfer, .functionality = iop3xx_i2c_func, }; static int iop3xx_i2c_remove(struct platform_device *pdev) { struct i2c_adapter *padapter = platform_get_drvdata(pdev); struct i2c_algo_iop3xx_data *adapter_data = (struct i2c_algo_iop3xx_data *)padapter->algo_data; struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET); /* * Disable the actual HW unit */ cr &= ~(IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE | IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE); __raw_writel(cr, adapter_data->ioaddr + CR_OFFSET); iounmap(adapter_data->ioaddr); release_mem_region(res->start, IOP3XX_I2C_IO_SIZE); kfree(adapter_data); kfree(padapter); return 0; } static int iop3xx_i2c_probe(struct platform_device *pdev) { struct resource *res; int ret, irq; struct i2c_adapter *new_adapter; struct i2c_algo_iop3xx_data *adapter_data; new_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); if (!new_adapter) { ret = -ENOMEM; goto out; } adapter_data = kzalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL); if (!adapter_data) { ret = -ENOMEM; goto free_adapter; } adapter_data->gpio_scl = devm_gpiod_get_optional(&pdev->dev, "scl", GPIOD_ASIS); if (IS_ERR(adapter_data->gpio_scl)) { ret = PTR_ERR(adapter_data->gpio_scl); goto free_both; } adapter_data->gpio_sda = devm_gpiod_get_optional(&pdev->dev, "sda", GPIOD_ASIS); if (IS_ERR(adapter_data->gpio_sda)) { ret = PTR_ERR(adapter_data->gpio_sda); goto free_both; } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { ret = -ENODEV; goto free_both; } if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) { ret = -EBUSY; goto free_both; } /* set the adapter enumeration # */ adapter_data->id = i2c_id++; adapter_data->ioaddr = ioremap(res->start, IOP3XX_I2C_IO_SIZE); if (!adapter_data->ioaddr) { ret = -ENOMEM; goto release_region; } irq = platform_get_irq(pdev, 0); if (irq < 0) { ret = irq; goto unmap; } ret = request_irq(irq, iop3xx_i2c_irq_handler, 0, pdev->name, adapter_data); if (ret) goto unmap; memcpy(new_adapter->name, pdev->name, strlen(pdev->name)); new_adapter->owner = THIS_MODULE; new_adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; new_adapter->dev.parent = &pdev->dev; new_adapter->dev.of_node = pdev->dev.of_node; new_adapter->nr = pdev->id; /* * Default values...should these come in from board code? */ new_adapter->timeout = HZ; new_adapter->algo = &iop3xx_i2c_algo; init_waitqueue_head(&adapter_data->waitq); spin_lock_init(&adapter_data->lock); iop3xx_i2c_reset(adapter_data); iop3xx_i2c_enable(adapter_data); platform_set_drvdata(pdev, new_adapter); new_adapter->algo_data = adapter_data; i2c_add_numbered_adapter(new_adapter); return 0; unmap: iounmap(adapter_data->ioaddr); release_region: release_mem_region(res->start, IOP3XX_I2C_IO_SIZE); free_both: kfree(adapter_data); free_adapter: kfree(new_adapter); out: return ret; } static const struct of_device_id i2c_iop3xx_match[] = { { .compatible = "intel,iop3xx-i2c", }, { .compatible = "intel,ixp4xx-i2c", }, {}, }; MODULE_DEVICE_TABLE(of, i2c_iop3xx_match); static struct platform_driver iop3xx_i2c_driver = { .probe = iop3xx_i2c_probe, .remove = iop3xx_i2c_remove, .driver = { .name = "IOP3xx-I2C", .of_match_table = i2c_iop3xx_match, }, }; module_platform_driver(iop3xx_i2c_driver); MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>"); MODULE_DESCRIPTION("IOP3xx iic algorithm and driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:IOP3xx-I2C"); |