1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * TI DAVINCI I2C adapter driver. 4 * 5 * Copyright (C) 2006 Texas Instruments. 6 * Copyright (C) 2007 MontaVista Software Inc. 7 * 8 * Updated by Vinod & Sudhakar Feb 2005 9 * 10 * ---------------------------------------------------------------------------- 11 * 12 * ---------------------------------------------------------------------------- 13 */ 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/delay.h> 17 #include <linux/i2c.h> 18 #include <linux/clk.h> 19 #include <linux/errno.h> 20 #include <linux/sched.h> 21 #include <linux/err.h> 22 #include <linux/interrupt.h> 23 #include <linux/platform_device.h> 24 #include <linux/io.h> 25 #include <linux/slab.h> 26 #include <linux/cpufreq.h> 27 #include <linux/gpio/consumer.h> 28 #include <linux/of.h> 29 #include <linux/platform_data/i2c-davinci.h> 30 #include <linux/pm_runtime.h> 31 32 /* ----- global defines ----------------------------------------------- */ 33 34 #define DAVINCI_I2C_TIMEOUT (1*HZ) 35 #define DAVINCI_I2C_MAX_TRIES 2 36 #define DAVINCI_I2C_OWN_ADDRESS 0x08 37 #define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_SCD | \ 38 DAVINCI_I2C_IMR_ARDY | \ 39 DAVINCI_I2C_IMR_NACK | \ 40 DAVINCI_I2C_IMR_AL) 41 42 #define DAVINCI_I2C_OAR_REG 0x00 43 #define DAVINCI_I2C_IMR_REG 0x04 44 #define DAVINCI_I2C_STR_REG 0x08 45 #define DAVINCI_I2C_CLKL_REG 0x0c 46 #define DAVINCI_I2C_CLKH_REG 0x10 47 #define DAVINCI_I2C_CNT_REG 0x14 48 #define DAVINCI_I2C_DRR_REG 0x18 49 #define DAVINCI_I2C_SAR_REG 0x1c 50 #define DAVINCI_I2C_DXR_REG 0x20 51 #define DAVINCI_I2C_MDR_REG 0x24 52 #define DAVINCI_I2C_IVR_REG 0x28 53 #define DAVINCI_I2C_EMDR_REG 0x2c 54 #define DAVINCI_I2C_PSC_REG 0x30 55 #define DAVINCI_I2C_FUNC_REG 0x48 56 #define DAVINCI_I2C_DIR_REG 0x4c 57 #define DAVINCI_I2C_DIN_REG 0x50 58 #define DAVINCI_I2C_DOUT_REG 0x54 59 #define DAVINCI_I2C_DSET_REG 0x58 60 #define DAVINCI_I2C_DCLR_REG 0x5c 61 62 #define DAVINCI_I2C_IVR_AAS 0x07 63 #define DAVINCI_I2C_IVR_SCD 0x06 64 #define DAVINCI_I2C_IVR_XRDY 0x05 65 #define DAVINCI_I2C_IVR_RDR 0x04 66 #define DAVINCI_I2C_IVR_ARDY 0x03 67 #define DAVINCI_I2C_IVR_NACK 0x02 68 #define DAVINCI_I2C_IVR_AL 0x01 69 70 #define DAVINCI_I2C_STR_BB BIT(12) 71 #define DAVINCI_I2C_STR_RSFULL BIT(11) 72 #define DAVINCI_I2C_STR_SCD BIT(5) 73 #define DAVINCI_I2C_STR_ARDY BIT(2) 74 #define DAVINCI_I2C_STR_NACK BIT(1) 75 #define DAVINCI_I2C_STR_AL BIT(0) 76 77 #define DAVINCI_I2C_MDR_NACK BIT(15) 78 #define DAVINCI_I2C_MDR_STT BIT(13) 79 #define DAVINCI_I2C_MDR_STP BIT(11) 80 #define DAVINCI_I2C_MDR_MST BIT(10) 81 #define DAVINCI_I2C_MDR_TRX BIT(9) 82 #define DAVINCI_I2C_MDR_XA BIT(8) 83 #define DAVINCI_I2C_MDR_RM BIT(7) 84 #define DAVINCI_I2C_MDR_IRS BIT(5) 85 86 #define DAVINCI_I2C_IMR_AAS BIT(6) 87 #define DAVINCI_I2C_IMR_SCD BIT(5) 88 #define DAVINCI_I2C_IMR_XRDY BIT(4) 89 #define DAVINCI_I2C_IMR_RRDY BIT(3) 90 #define DAVINCI_I2C_IMR_ARDY BIT(2) 91 #define DAVINCI_I2C_IMR_NACK BIT(1) 92 #define DAVINCI_I2C_IMR_AL BIT(0) 93 94 /* set SDA and SCL as GPIO */ 95 #define DAVINCI_I2C_FUNC_PFUNC0 BIT(0) 96 97 /* set SCL as output when used as GPIO*/ 98 #define DAVINCI_I2C_DIR_PDIR0 BIT(0) 99 /* set SDA as output when used as GPIO*/ 100 #define DAVINCI_I2C_DIR_PDIR1 BIT(1) 101 102 /* read SCL GPIO level */ 103 #define DAVINCI_I2C_DIN_PDIN0 BIT(0) 104 /* read SDA GPIO level */ 105 #define DAVINCI_I2C_DIN_PDIN1 BIT(1) 106 107 /*set the SCL GPIO high */ 108 #define DAVINCI_I2C_DSET_PDSET0 BIT(0) 109 /*set the SDA GPIO high */ 110 #define DAVINCI_I2C_DSET_PDSET1 BIT(1) 111 112 /* set the SCL GPIO low */ 113 #define DAVINCI_I2C_DCLR_PDCLR0 BIT(0) 114 /* set the SDA GPIO low */ 115 #define DAVINCI_I2C_DCLR_PDCLR1 BIT(1) 116 117 /* timeout for pm runtime autosuspend */ 118 #define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */ 119 120 struct davinci_i2c_dev { 121 struct device *dev; 122 void __iomem *base; 123 struct completion cmd_complete; 124 struct clk *clk; 125 int cmd_err; 126 u8 *buf; 127 size_t buf_len; 128 int irq; 129 int stop; 130 u8 terminate; 131 struct i2c_adapter adapter; 132 #ifdef CONFIG_CPU_FREQ 133 struct notifier_block freq_transition; 134 #endif 135 struct davinci_i2c_platform_data *pdata; 136 }; 137 138 /* default platform data to use if not supplied in the platform_device */ 139 static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = { 140 .bus_freq = 100, 141 .bus_delay = 0, 142 }; 143 144 static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev, 145 int reg, u16 val) 146 { 147 writew_relaxed(val, i2c_dev->base + reg); 148 } 149 150 static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) 151 { 152 return readw_relaxed(i2c_dev->base + reg); 153 } 154 155 static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, 156 int val) 157 { 158 u16 w; 159 160 w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG); 161 if (!val) /* put I2C into reset */ 162 w &= ~DAVINCI_I2C_MDR_IRS; 163 else /* take I2C out of reset */ 164 w |= DAVINCI_I2C_MDR_IRS; 165 166 davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w); 167 } 168 169 static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev) 170 { 171 struct davinci_i2c_platform_data *pdata = dev->pdata; 172 u16 psc; 173 u32 clk; 174 u32 d; 175 u32 clkh; 176 u32 clkl; 177 u32 input_clock = clk_get_rate(dev->clk); 178 struct device_node *of_node = dev->dev->of_node; 179 180 /* NOTE: I2C Clock divider programming info 181 * As per I2C specs the following formulas provide prescaler 182 * and low/high divider values 183 * input clk --> PSC Div -----------> ICCL/H Div --> output clock 184 * module clk 185 * 186 * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ] 187 * 188 * Thus, 189 * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d; 190 * 191 * where if PSC == 0, d = 7, 192 * if PSC == 1, d = 6 193 * if PSC > 1 , d = 5 194 * 195 * Note: 196 * d is always 6 on Keystone I2C controller 197 */ 198 199 /* 200 * Both Davinci and current Keystone User Guides recommend a value 201 * between 7MHz and 12MHz. In reality 7MHz module clock doesn't 202 * always produce enough margin between SDA and SCL transitions. 203 * Measurements show that the higher the module clock is, the 204 * bigger is the margin, providing more reliable communication. 205 * So we better target for 12MHz. 206 */ 207 psc = (input_clock / 12000000) - 1; 208 if ((input_clock / (psc + 1)) > 12000000) 209 psc++; /* better to run under spec than over */ 210 d = (psc >= 2) ? 5 : 7 - psc; 211 212 if (of_node && of_device_is_compatible(of_node, "ti,keystone-i2c")) 213 d = 6; 214 215 clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)); 216 /* Avoid driving the bus too fast because of rounding errors above */ 217 if (input_clock / (psc + 1) / clk > pdata->bus_freq * 1000) 218 clk++; 219 /* 220 * According to I2C-BUS Spec 2.1, in FAST-MODE LOW period should be at 221 * least 1.3uS, which is not the case with 50% duty cycle. Driving HIGH 222 * to LOW ratio as 1 to 2 is more safe. 223 */ 224 if (pdata->bus_freq > 100) 225 clkl = (clk << 1) / 3; 226 else 227 clkl = (clk >> 1); 228 /* 229 * It's not always possible to have 1 to 2 ratio when d=7, so fall back 230 * to minimal possible clkh in this case. 231 * 232 * Note: 233 * CLKH is not allowed to be 0, in this case I2C clock is not generated 234 * at all 235 */ 236 if (clk > clkl + d) { 237 clkh = clk - clkl - d; 238 clkl -= d; 239 } else { 240 clkh = 1; 241 clkl = clk - (d << 1); 242 } 243 244 davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc); 245 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh); 246 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl); 247 248 dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); 249 } 250 251 /* 252 * This function configures I2C and brings I2C out of reset. 253 * This function is called during I2C init function. This function 254 * also gets called if I2C encounters any errors. 255 */ 256 static int i2c_davinci_init(struct davinci_i2c_dev *dev) 257 { 258 struct davinci_i2c_platform_data *pdata = dev->pdata; 259 260 /* put I2C into reset */ 261 davinci_i2c_reset_ctrl(dev, 0); 262 263 /* compute clock dividers */ 264 i2c_davinci_calc_clk_dividers(dev); 265 266 /* Respond at reserved "SMBus Host" target address" (and zero); 267 * we seem to have no option to not respond... 268 */ 269 davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, DAVINCI_I2C_OWN_ADDRESS); 270 271 dev_dbg(dev->dev, "PSC = %d\n", 272 davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG)); 273 dev_dbg(dev->dev, "CLKL = %d\n", 274 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG)); 275 dev_dbg(dev->dev, "CLKH = %d\n", 276 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG)); 277 dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n", 278 pdata->bus_freq, pdata->bus_delay); 279 280 281 /* Take the I2C module out of reset: */ 282 davinci_i2c_reset_ctrl(dev, 1); 283 284 /* Enable interrupts */ 285 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL); 286 287 return 0; 288 } 289 290 /* 291 * This routine does i2c bus recovery by using i2c_generic_scl_recovery 292 * which is provided by I2C Bus recovery infrastructure. 293 */ 294 static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap) 295 { 296 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 297 298 /* Disable interrupts */ 299 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0); 300 301 /* put I2C into reset */ 302 davinci_i2c_reset_ctrl(dev, 0); 303 } 304 305 static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap) 306 { 307 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 308 309 i2c_davinci_init(dev); 310 } 311 312 static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = { 313 .recover_bus = i2c_generic_scl_recovery, 314 .prepare_recovery = davinci_i2c_prepare_recovery, 315 .unprepare_recovery = davinci_i2c_unprepare_recovery, 316 }; 317 318 static void davinci_i2c_set_scl(struct i2c_adapter *adap, int val) 319 { 320 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 321 322 if (val) 323 davinci_i2c_write_reg(dev, DAVINCI_I2C_DSET_REG, 324 DAVINCI_I2C_DSET_PDSET0); 325 else 326 davinci_i2c_write_reg(dev, DAVINCI_I2C_DCLR_REG, 327 DAVINCI_I2C_DCLR_PDCLR0); 328 } 329 330 static int davinci_i2c_get_scl(struct i2c_adapter *adap) 331 { 332 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 333 int val; 334 335 /* read the state of SCL */ 336 val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG); 337 return val & DAVINCI_I2C_DIN_PDIN0; 338 } 339 340 static int davinci_i2c_get_sda(struct i2c_adapter *adap) 341 { 342 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 343 int val; 344 345 /* read the state of SDA */ 346 val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG); 347 return val & DAVINCI_I2C_DIN_PDIN1; 348 } 349 350 static void davinci_i2c_scl_prepare_recovery(struct i2c_adapter *adap) 351 { 352 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 353 354 davinci_i2c_prepare_recovery(adap); 355 356 /* SCL output, SDA input */ 357 davinci_i2c_write_reg(dev, DAVINCI_I2C_DIR_REG, DAVINCI_I2C_DIR_PDIR0); 358 359 /* change to GPIO mode */ 360 davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 361 DAVINCI_I2C_FUNC_PFUNC0); 362 } 363 364 static void davinci_i2c_scl_unprepare_recovery(struct i2c_adapter *adap) 365 { 366 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 367 368 /* change back to I2C mode */ 369 davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 0); 370 371 davinci_i2c_unprepare_recovery(adap); 372 } 373 374 static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = { 375 .recover_bus = i2c_generic_scl_recovery, 376 .set_scl = davinci_i2c_set_scl, 377 .get_scl = davinci_i2c_get_scl, 378 .get_sda = davinci_i2c_get_sda, 379 .prepare_recovery = davinci_i2c_scl_prepare_recovery, 380 .unprepare_recovery = davinci_i2c_scl_unprepare_recovery, 381 }; 382 383 /* 384 * Waiting for bus not busy 385 */ 386 static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev) 387 { 388 unsigned long timeout = jiffies + dev->adapter.timeout; 389 390 do { 391 if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)) 392 return 0; 393 schedule_timeout_uninterruptible(1); 394 } while (time_before_eq(jiffies, timeout)); 395 396 dev_warn(dev->dev, "timeout waiting for bus ready\n"); 397 i2c_recover_bus(&dev->adapter); 398 399 /* 400 * if bus is still "busy" here, it's most probably a HW problem like 401 * short-circuit 402 */ 403 if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB) 404 return -EIO; 405 406 return 0; 407 } 408 409 /* 410 * Low level read/write transaction. This function is called from 411 * i2c_davinci_xfer. 412 */ 413 static int 414 i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) 415 { 416 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 417 struct davinci_i2c_platform_data *pdata = dev->pdata; 418 u32 flag; 419 u16 w; 420 unsigned long time_left; 421 422 if (msg->addr == DAVINCI_I2C_OWN_ADDRESS) { 423 dev_warn(dev->dev, "transfer to own address aborted\n"); 424 return -EADDRNOTAVAIL; 425 } 426 427 /* Introduce a delay, required for some boards (e.g Davinci EVM) */ 428 if (pdata->bus_delay) 429 udelay(pdata->bus_delay); 430 431 /* set the target address */ 432 davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr); 433 434 dev->buf = msg->buf; 435 dev->buf_len = msg->len; 436 dev->stop = stop; 437 438 davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); 439 440 reinit_completion(&dev->cmd_complete); 441 dev->cmd_err = 0; 442 443 /* Take I2C out of reset and configure it as controller */ 444 flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST; 445 446 if (msg->flags & I2C_M_TEN) 447 flag |= DAVINCI_I2C_MDR_XA; 448 if (!(msg->flags & I2C_M_RD)) 449 flag |= DAVINCI_I2C_MDR_TRX; 450 if (msg->len == 0) 451 flag |= DAVINCI_I2C_MDR_RM; 452 453 /* Enable receive or transmit interrupts */ 454 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); 455 if (msg->flags & I2C_M_RD) 456 w |= DAVINCI_I2C_IMR_RRDY; 457 else 458 w |= DAVINCI_I2C_IMR_XRDY; 459 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); 460 461 dev->terminate = 0; 462 463 /* 464 * Write mode register first as needed for correct behaviour 465 * on OMAP-L138, but don't set STT yet to avoid a race with XRDY 466 * occurring before we have loaded DXR 467 */ 468 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); 469 470 /* 471 * First byte should be set here, not after interrupt, 472 * because transmit-data-ready interrupt can come before 473 * NACK-interrupt during sending of previous message and 474 * ICDXR may have wrong data 475 * It also saves us one interrupt, slightly faster 476 */ 477 if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) { 478 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++); 479 dev->buf_len--; 480 } 481 482 /* Set STT to begin transmit now DXR is loaded */ 483 flag |= DAVINCI_I2C_MDR_STT; 484 if (stop && msg->len != 0) 485 flag |= DAVINCI_I2C_MDR_STP; 486 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); 487 488 time_left = wait_for_completion_timeout(&dev->cmd_complete, 489 dev->adapter.timeout); 490 if (!time_left) { 491 i2c_recover_bus(adap); 492 dev->buf_len = 0; 493 return -ETIMEDOUT; 494 } 495 if (dev->buf_len) { 496 /* This should be 0 if all bytes were transferred 497 * or dev->cmd_err denotes an error. 498 */ 499 dev_err(dev->dev, "abnormal termination buf_len=%zu\n", 500 dev->buf_len); 501 dev->terminate = 1; 502 wmb(); 503 dev->buf_len = 0; 504 return -EREMOTEIO; 505 } 506 507 /* no error */ 508 if (likely(!dev->cmd_err)) 509 return msg->len; 510 511 /* We have an error */ 512 if (dev->cmd_err & DAVINCI_I2C_STR_AL) { 513 i2c_davinci_init(dev); 514 return -EIO; 515 } 516 517 if (dev->cmd_err & DAVINCI_I2C_STR_NACK) { 518 if (msg->flags & I2C_M_IGNORE_NAK) 519 return msg->len; 520 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); 521 w |= DAVINCI_I2C_MDR_STP; 522 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); 523 return -EREMOTEIO; 524 } 525 return -EIO; 526 } 527 528 /* 529 * Prepare controller for a transaction and call i2c_davinci_xfer_msg 530 */ 531 static int 532 i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 533 { 534 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); 535 int i; 536 int ret; 537 538 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); 539 540 ret = pm_runtime_resume_and_get(dev->dev); 541 if (ret < 0) { 542 dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret); 543 return ret; 544 } 545 546 ret = i2c_davinci_wait_bus_not_busy(dev); 547 if (ret < 0) { 548 dev_warn(dev->dev, "timeout waiting for bus ready\n"); 549 goto out; 550 } 551 552 for (i = 0; i < num; i++) { 553 ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1))); 554 dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num, 555 ret); 556 if (ret < 0) 557 goto out; 558 } 559 560 ret = num; 561 562 out: 563 pm_runtime_mark_last_busy(dev->dev); 564 pm_runtime_put_autosuspend(dev->dev); 565 566 return ret; 567 } 568 569 static u32 i2c_davinci_func(struct i2c_adapter *adap) 570 { 571 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 572 } 573 574 static void terminate_read(struct davinci_i2c_dev *dev) 575 { 576 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); 577 w |= DAVINCI_I2C_MDR_NACK; 578 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); 579 580 /* Throw away data */ 581 davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG); 582 if (!dev->terminate) 583 dev_err(dev->dev, "RDR IRQ while no data requested\n"); 584 } 585 static void terminate_write(struct davinci_i2c_dev *dev) 586 { 587 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); 588 w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP; 589 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); 590 591 if (!dev->terminate) 592 dev_dbg(dev->dev, "TDR IRQ while no data to send\n"); 593 } 594 595 /* 596 * Interrupt service routine. This gets called whenever an I2C interrupt 597 * occurs. 598 */ 599 static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) 600 { 601 struct davinci_i2c_dev *dev = dev_id; 602 u32 stat; 603 int count = 0; 604 u16 w; 605 606 if (pm_runtime_suspended(dev->dev)) 607 return IRQ_NONE; 608 609 while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) { 610 dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat); 611 if (count++ == 100) { 612 dev_warn(dev->dev, "Too much work in one IRQ\n"); 613 break; 614 } 615 616 switch (stat) { 617 case DAVINCI_I2C_IVR_AL: 618 /* Arbitration lost, must retry */ 619 dev->cmd_err |= DAVINCI_I2C_STR_AL; 620 dev->buf_len = 0; 621 complete(&dev->cmd_complete); 622 break; 623 624 case DAVINCI_I2C_IVR_NACK: 625 dev->cmd_err |= DAVINCI_I2C_STR_NACK; 626 dev->buf_len = 0; 627 complete(&dev->cmd_complete); 628 break; 629 630 case DAVINCI_I2C_IVR_ARDY: 631 davinci_i2c_write_reg(dev, 632 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY); 633 if (((dev->buf_len == 0) && (dev->stop != 0)) || 634 (dev->cmd_err & DAVINCI_I2C_STR_NACK)) { 635 w = davinci_i2c_read_reg(dev, 636 DAVINCI_I2C_MDR_REG); 637 w |= DAVINCI_I2C_MDR_STP; 638 davinci_i2c_write_reg(dev, 639 DAVINCI_I2C_MDR_REG, w); 640 } 641 complete(&dev->cmd_complete); 642 break; 643 644 case DAVINCI_I2C_IVR_RDR: 645 if (dev->buf_len) { 646 *dev->buf++ = 647 davinci_i2c_read_reg(dev, 648 DAVINCI_I2C_DRR_REG); 649 dev->buf_len--; 650 if (dev->buf_len) 651 continue; 652 653 davinci_i2c_write_reg(dev, 654 DAVINCI_I2C_STR_REG, 655 DAVINCI_I2C_IMR_RRDY); 656 } else { 657 /* signal can terminate transfer */ 658 terminate_read(dev); 659 } 660 break; 661 662 case DAVINCI_I2C_IVR_XRDY: 663 if (dev->buf_len) { 664 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, 665 *dev->buf++); 666 dev->buf_len--; 667 if (dev->buf_len) 668 continue; 669 670 w = davinci_i2c_read_reg(dev, 671 DAVINCI_I2C_IMR_REG); 672 w &= ~DAVINCI_I2C_IMR_XRDY; 673 davinci_i2c_write_reg(dev, 674 DAVINCI_I2C_IMR_REG, 675 w); 676 } else { 677 /* signal can terminate transfer */ 678 terminate_write(dev); 679 } 680 break; 681 682 case DAVINCI_I2C_IVR_SCD: 683 davinci_i2c_write_reg(dev, 684 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD); 685 complete(&dev->cmd_complete); 686 break; 687 688 case DAVINCI_I2C_IVR_AAS: 689 dev_dbg(dev->dev, "Address as target interrupt\n"); 690 break; 691 692 default: 693 dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat); 694 break; 695 } 696 } 697 698 return count ? IRQ_HANDLED : IRQ_NONE; 699 } 700 701 #ifdef CONFIG_CPU_FREQ 702 static int i2c_davinci_cpufreq_transition(struct notifier_block *nb, 703 unsigned long val, void *data) 704 { 705 struct davinci_i2c_dev *dev; 706 707 dev = container_of(nb, struct davinci_i2c_dev, freq_transition); 708 709 i2c_lock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER); 710 if (val == CPUFREQ_PRECHANGE) { 711 davinci_i2c_reset_ctrl(dev, 0); 712 } else if (val == CPUFREQ_POSTCHANGE) { 713 i2c_davinci_calc_clk_dividers(dev); 714 davinci_i2c_reset_ctrl(dev, 1); 715 } 716 i2c_unlock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER); 717 718 return 0; 719 } 720 721 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) 722 { 723 dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition; 724 725 return cpufreq_register_notifier(&dev->freq_transition, 726 CPUFREQ_TRANSITION_NOTIFIER); 727 } 728 729 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) 730 { 731 cpufreq_unregister_notifier(&dev->freq_transition, 732 CPUFREQ_TRANSITION_NOTIFIER); 733 } 734 #else 735 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) 736 { 737 return 0; 738 } 739 740 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) 741 { 742 } 743 #endif 744 745 static const struct i2c_algorithm i2c_davinci_algo = { 746 .xfer = i2c_davinci_xfer, 747 .functionality = i2c_davinci_func, 748 }; 749 750 static const struct of_device_id davinci_i2c_of_match[] = { 751 {.compatible = "ti,davinci-i2c", }, 752 {.compatible = "ti,keystone-i2c", }, 753 {}, 754 }; 755 MODULE_DEVICE_TABLE(of, davinci_i2c_of_match); 756 757 static int davinci_i2c_probe(struct platform_device *pdev) 758 { 759 struct davinci_i2c_dev *dev; 760 struct i2c_adapter *adap; 761 struct i2c_bus_recovery_info *rinfo; 762 int r, irq; 763 764 irq = platform_get_irq(pdev, 0); 765 if (irq < 0) 766 return irq; 767 768 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); 769 if (!dev) 770 return -ENOMEM; 771 772 init_completion(&dev->cmd_complete); 773 774 dev->dev = &pdev->dev; 775 dev->irq = irq; 776 dev->pdata = dev_get_platdata(&pdev->dev); 777 platform_set_drvdata(pdev, dev); 778 779 if (!dev->pdata && pdev->dev.of_node) { 780 u32 prop; 781 782 dev->pdata = devm_kzalloc(&pdev->dev, 783 sizeof(struct davinci_i2c_platform_data), GFP_KERNEL); 784 if (!dev->pdata) 785 return -ENOMEM; 786 787 memcpy(dev->pdata, &davinci_i2c_platform_data_default, 788 sizeof(struct davinci_i2c_platform_data)); 789 if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency", 790 &prop)) 791 dev->pdata->bus_freq = prop / 1000; 792 793 dev->pdata->has_pfunc = 794 of_property_read_bool(pdev->dev.of_node, 795 "ti,has-pfunc"); 796 } else if (!dev->pdata) { 797 dev->pdata = &davinci_i2c_platform_data_default; 798 } 799 800 dev->clk = devm_clk_get(&pdev->dev, NULL); 801 if (IS_ERR(dev->clk)) 802 return PTR_ERR(dev->clk); 803 804 dev->base = devm_platform_ioremap_resource(pdev, 0); 805 if (IS_ERR(dev->base)) { 806 return PTR_ERR(dev->base); 807 } 808 809 pm_runtime_set_autosuspend_delay(dev->dev, 810 DAVINCI_I2C_PM_TIMEOUT); 811 pm_runtime_use_autosuspend(dev->dev); 812 813 pm_runtime_enable(dev->dev); 814 815 r = pm_runtime_resume_and_get(dev->dev); 816 if (r < 0) { 817 dev_err(dev->dev, "failed to runtime_get device: %d\n", r); 818 goto err_pm; 819 } 820 821 i2c_davinci_init(dev); 822 823 r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0, 824 pdev->name, dev); 825 if (r) { 826 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 827 goto err_unuse_clocks; 828 } 829 830 r = i2c_davinci_cpufreq_register(dev); 831 if (r) { 832 dev_err(&pdev->dev, "failed to register cpufreq\n"); 833 goto err_unuse_clocks; 834 } 835 836 adap = &dev->adapter; 837 i2c_set_adapdata(adap, dev); 838 adap->owner = THIS_MODULE; 839 adap->class = I2C_CLASS_DEPRECATED; 840 strscpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name)); 841 adap->algo = &i2c_davinci_algo; 842 adap->dev.parent = &pdev->dev; 843 adap->timeout = DAVINCI_I2C_TIMEOUT; 844 adap->dev.of_node = pdev->dev.of_node; 845 846 if (dev->pdata->has_pfunc) 847 adap->bus_recovery_info = &davinci_i2c_scl_recovery_info; 848 else if (dev->pdata->gpio_recovery) { 849 rinfo = &davinci_i2c_gpio_recovery_info; 850 adap->bus_recovery_info = rinfo; 851 rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", 852 GPIOD_OUT_HIGH_OPEN_DRAIN); 853 if (IS_ERR(rinfo->scl_gpiod)) { 854 r = PTR_ERR(rinfo->scl_gpiod); 855 goto err_unuse_clocks; 856 } 857 rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN); 858 if (IS_ERR(rinfo->sda_gpiod)) { 859 r = PTR_ERR(rinfo->sda_gpiod); 860 goto err_unuse_clocks; 861 } 862 } 863 864 adap->nr = pdev->id; 865 r = i2c_add_numbered_adapter(adap); 866 if (r) 867 goto err_unuse_clocks; 868 869 pm_runtime_mark_last_busy(dev->dev); 870 pm_runtime_put_autosuspend(dev->dev); 871 872 return 0; 873 874 err_unuse_clocks: 875 pm_runtime_dont_use_autosuspend(dev->dev); 876 pm_runtime_put_sync(dev->dev); 877 err_pm: 878 pm_runtime_disable(dev->dev); 879 880 return r; 881 } 882 883 static void davinci_i2c_remove(struct platform_device *pdev) 884 { 885 struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); 886 int ret; 887 888 i2c_davinci_cpufreq_deregister(dev); 889 890 i2c_del_adapter(&dev->adapter); 891 892 ret = pm_runtime_get_sync(&pdev->dev); 893 if (ret < 0) 894 dev_err(&pdev->dev, "Failed to resume device\n"); 895 else 896 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0); 897 898 pm_runtime_dont_use_autosuspend(dev->dev); 899 pm_runtime_put_sync(dev->dev); 900 pm_runtime_disable(dev->dev); 901 } 902 903 static int davinci_i2c_suspend(struct device *dev) 904 { 905 struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev); 906 907 /* put I2C into reset */ 908 davinci_i2c_reset_ctrl(i2c_dev, 0); 909 910 return 0; 911 } 912 913 static int davinci_i2c_resume(struct device *dev) 914 { 915 struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev); 916 917 /* take I2C out of reset */ 918 davinci_i2c_reset_ctrl(i2c_dev, 1); 919 920 return 0; 921 } 922 923 static const struct dev_pm_ops davinci_i2c_pm = { 924 .suspend = davinci_i2c_suspend, 925 .resume = davinci_i2c_resume, 926 NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 927 pm_runtime_force_resume) 928 }; 929 930 static const struct platform_device_id davinci_i2c_driver_ids[] = { 931 { .name = "i2c_davinci", }, 932 { /* sentinel */ } 933 }; 934 MODULE_DEVICE_TABLE(platform, davinci_i2c_driver_ids); 935 936 static struct platform_driver davinci_i2c_driver = { 937 .probe = davinci_i2c_probe, 938 .remove = davinci_i2c_remove, 939 .id_table = davinci_i2c_driver_ids, 940 .driver = { 941 .name = "i2c_davinci", 942 .pm = pm_sleep_ptr(&davinci_i2c_pm), 943 .of_match_table = davinci_i2c_of_match, 944 }, 945 }; 946 947 /* I2C may be needed to bring up other drivers */ 948 static int __init davinci_i2c_init_driver(void) 949 { 950 return platform_driver_register(&davinci_i2c_driver); 951 } 952 subsys_initcall(davinci_i2c_init_driver); 953 954 static void __exit davinci_i2c_exit_driver(void) 955 { 956 platform_driver_unregister(&davinci_i2c_driver); 957 } 958 module_exit(davinci_i2c_exit_driver); 959 960 MODULE_AUTHOR("Texas Instruments India"); 961 MODULE_DESCRIPTION("TI DaVinci I2C bus adapter"); 962 MODULE_LICENSE("GPL"); 963