1 /* 2 * rtc-twl.c -- TWL Real Time Clock interface 3 * 4 * Copyright (C) 2007 MontaVista Software, Inc 5 * Author: Alexandre Rusev <source@mvista.com> 6 * 7 * Based on original TI driver twl4030-rtc.c 8 * Copyright (C) 2006 Texas Instruments, Inc. 9 * 10 * Based on rtc-omap.c 11 * Copyright (C) 2003 MontaVista Software, Inc. 12 * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com> 13 * Copyright (C) 2006 David Brownell 14 * 15 * This program is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU General Public License 17 * as published by the Free Software Foundation; either version 18 * 2 of the License, or (at your option) any later version. 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/errno.h> 23 #include <linux/init.h> 24 #include <linux/module.h> 25 #include <linux/types.h> 26 #include <linux/rtc.h> 27 #include <linux/bcd.h> 28 #include <linux/platform_device.h> 29 #include <linux/interrupt.h> 30 31 #include <linux/i2c/twl.h> 32 33 34 /* 35 * RTC block register offsets (use TWL_MODULE_RTC) 36 */ 37 enum { 38 REG_SECONDS_REG = 0, 39 REG_MINUTES_REG, 40 REG_HOURS_REG, 41 REG_DAYS_REG, 42 REG_MONTHS_REG, 43 REG_YEARS_REG, 44 REG_WEEKS_REG, 45 46 REG_ALARM_SECONDS_REG, 47 REG_ALARM_MINUTES_REG, 48 REG_ALARM_HOURS_REG, 49 REG_ALARM_DAYS_REG, 50 REG_ALARM_MONTHS_REG, 51 REG_ALARM_YEARS_REG, 52 53 REG_RTC_CTRL_REG, 54 REG_RTC_STATUS_REG, 55 REG_RTC_INTERRUPTS_REG, 56 57 REG_RTC_COMP_LSB_REG, 58 REG_RTC_COMP_MSB_REG, 59 }; 60 static const u8 twl4030_rtc_reg_map[] = { 61 [REG_SECONDS_REG] = 0x00, 62 [REG_MINUTES_REG] = 0x01, 63 [REG_HOURS_REG] = 0x02, 64 [REG_DAYS_REG] = 0x03, 65 [REG_MONTHS_REG] = 0x04, 66 [REG_YEARS_REG] = 0x05, 67 [REG_WEEKS_REG] = 0x06, 68 69 [REG_ALARM_SECONDS_REG] = 0x07, 70 [REG_ALARM_MINUTES_REG] = 0x08, 71 [REG_ALARM_HOURS_REG] = 0x09, 72 [REG_ALARM_DAYS_REG] = 0x0A, 73 [REG_ALARM_MONTHS_REG] = 0x0B, 74 [REG_ALARM_YEARS_REG] = 0x0C, 75 76 [REG_RTC_CTRL_REG] = 0x0D, 77 [REG_RTC_STATUS_REG] = 0x0E, 78 [REG_RTC_INTERRUPTS_REG] = 0x0F, 79 80 [REG_RTC_COMP_LSB_REG] = 0x10, 81 [REG_RTC_COMP_MSB_REG] = 0x11, 82 }; 83 static const u8 twl6030_rtc_reg_map[] = { 84 [REG_SECONDS_REG] = 0x00, 85 [REG_MINUTES_REG] = 0x01, 86 [REG_HOURS_REG] = 0x02, 87 [REG_DAYS_REG] = 0x03, 88 [REG_MONTHS_REG] = 0x04, 89 [REG_YEARS_REG] = 0x05, 90 [REG_WEEKS_REG] = 0x06, 91 92 [REG_ALARM_SECONDS_REG] = 0x08, 93 [REG_ALARM_MINUTES_REG] = 0x09, 94 [REG_ALARM_HOURS_REG] = 0x0A, 95 [REG_ALARM_DAYS_REG] = 0x0B, 96 [REG_ALARM_MONTHS_REG] = 0x0C, 97 [REG_ALARM_YEARS_REG] = 0x0D, 98 99 [REG_RTC_CTRL_REG] = 0x10, 100 [REG_RTC_STATUS_REG] = 0x11, 101 [REG_RTC_INTERRUPTS_REG] = 0x12, 102 103 [REG_RTC_COMP_LSB_REG] = 0x13, 104 [REG_RTC_COMP_MSB_REG] = 0x14, 105 }; 106 107 /* RTC_CTRL_REG bitfields */ 108 #define BIT_RTC_CTRL_REG_STOP_RTC_M 0x01 109 #define BIT_RTC_CTRL_REG_ROUND_30S_M 0x02 110 #define BIT_RTC_CTRL_REG_AUTO_COMP_M 0x04 111 #define BIT_RTC_CTRL_REG_MODE_12_24_M 0x08 112 #define BIT_RTC_CTRL_REG_TEST_MODE_M 0x10 113 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M 0x20 114 #define BIT_RTC_CTRL_REG_GET_TIME_M 0x40 115 116 /* RTC_STATUS_REG bitfields */ 117 #define BIT_RTC_STATUS_REG_RUN_M 0x02 118 #define BIT_RTC_STATUS_REG_1S_EVENT_M 0x04 119 #define BIT_RTC_STATUS_REG_1M_EVENT_M 0x08 120 #define BIT_RTC_STATUS_REG_1H_EVENT_M 0x10 121 #define BIT_RTC_STATUS_REG_1D_EVENT_M 0x20 122 #define BIT_RTC_STATUS_REG_ALARM_M 0x40 123 #define BIT_RTC_STATUS_REG_POWER_UP_M 0x80 124 125 /* RTC_INTERRUPTS_REG bitfields */ 126 #define BIT_RTC_INTERRUPTS_REG_EVERY_M 0x03 127 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M 0x04 128 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M 0x08 129 130 131 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */ 132 #define ALL_TIME_REGS 6 133 134 /*----------------------------------------------------------------------*/ 135 static u8 *rtc_reg_map; 136 137 /* 138 * Supports 1 byte read from TWL RTC register. 139 */ 140 static int twl_rtc_read_u8(u8 *data, u8 reg) 141 { 142 int ret; 143 144 ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg])); 145 if (ret < 0) 146 pr_err("twl_rtc: Could not read TWL" 147 "register %X - error %d\n", reg, ret); 148 return ret; 149 } 150 151 /* 152 * Supports 1 byte write to TWL RTC registers. 153 */ 154 static int twl_rtc_write_u8(u8 data, u8 reg) 155 { 156 int ret; 157 158 ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg])); 159 if (ret < 0) 160 pr_err("twl_rtc: Could not write TWL" 161 "register %X - error %d\n", reg, ret); 162 return ret; 163 } 164 165 /* 166 * Cache the value for timer/alarm interrupts register; this is 167 * only changed by callers holding rtc ops lock (or resume). 168 */ 169 static unsigned char rtc_irq_bits; 170 171 /* 172 * Enable 1/second update and/or alarm interrupts. 173 */ 174 static int set_rtc_irq_bit(unsigned char bit) 175 { 176 unsigned char val; 177 int ret; 178 179 val = rtc_irq_bits | bit; 180 val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M; 181 ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG); 182 if (ret == 0) 183 rtc_irq_bits = val; 184 185 return ret; 186 } 187 188 /* 189 * Disable update and/or alarm interrupts. 190 */ 191 static int mask_rtc_irq_bit(unsigned char bit) 192 { 193 unsigned char val; 194 int ret; 195 196 val = rtc_irq_bits & ~bit; 197 ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG); 198 if (ret == 0) 199 rtc_irq_bits = val; 200 201 return ret; 202 } 203 204 static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) 205 { 206 int ret; 207 208 if (enabled) 209 ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); 210 else 211 ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); 212 213 return ret; 214 } 215 216 static int twl_rtc_update_irq_enable(struct device *dev, unsigned enabled) 217 { 218 int ret; 219 220 if (enabled) 221 ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); 222 else 223 ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); 224 225 return ret; 226 } 227 228 /* 229 * Gets current TWL RTC time and date parameters. 230 * 231 * The RTC's time/alarm representation is not what gmtime(3) requires 232 * Linux to use: 233 * 234 * - Months are 1..12 vs Linux 0-11 235 * - Years are 0..99 vs Linux 1900..N (we assume 21st century) 236 */ 237 static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm) 238 { 239 unsigned char rtc_data[ALL_TIME_REGS + 1]; 240 int ret; 241 u8 save_control; 242 243 ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG); 244 if (ret < 0) 245 return ret; 246 247 save_control |= BIT_RTC_CTRL_REG_GET_TIME_M; 248 249 ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG); 250 if (ret < 0) 251 return ret; 252 253 ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data, 254 (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS); 255 256 if (ret < 0) { 257 dev_err(dev, "rtc_read_time error %d\n", ret); 258 return ret; 259 } 260 261 tm->tm_sec = bcd2bin(rtc_data[0]); 262 tm->tm_min = bcd2bin(rtc_data[1]); 263 tm->tm_hour = bcd2bin(rtc_data[2]); 264 tm->tm_mday = bcd2bin(rtc_data[3]); 265 tm->tm_mon = bcd2bin(rtc_data[4]) - 1; 266 tm->tm_year = bcd2bin(rtc_data[5]) + 100; 267 268 return ret; 269 } 270 271 static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm) 272 { 273 unsigned char save_control; 274 unsigned char rtc_data[ALL_TIME_REGS + 1]; 275 int ret; 276 277 rtc_data[1] = bin2bcd(tm->tm_sec); 278 rtc_data[2] = bin2bcd(tm->tm_min); 279 rtc_data[3] = bin2bcd(tm->tm_hour); 280 rtc_data[4] = bin2bcd(tm->tm_mday); 281 rtc_data[5] = bin2bcd(tm->tm_mon + 1); 282 rtc_data[6] = bin2bcd(tm->tm_year - 100); 283 284 /* Stop RTC while updating the TC registers */ 285 ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG); 286 if (ret < 0) 287 goto out; 288 289 save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M; 290 twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG); 291 if (ret < 0) 292 goto out; 293 294 /* update all the time registers in one shot */ 295 ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data, 296 (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS); 297 if (ret < 0) { 298 dev_err(dev, "rtc_set_time error %d\n", ret); 299 goto out; 300 } 301 302 /* Start back RTC */ 303 save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M; 304 ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG); 305 306 out: 307 return ret; 308 } 309 310 /* 311 * Gets current TWL RTC alarm time. 312 */ 313 static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 314 { 315 unsigned char rtc_data[ALL_TIME_REGS + 1]; 316 int ret; 317 318 ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data, 319 (rtc_reg_map[REG_ALARM_SECONDS_REG]), ALL_TIME_REGS); 320 if (ret < 0) { 321 dev_err(dev, "rtc_read_alarm error %d\n", ret); 322 return ret; 323 } 324 325 /* some of these fields may be wildcard/"match all" */ 326 alm->time.tm_sec = bcd2bin(rtc_data[0]); 327 alm->time.tm_min = bcd2bin(rtc_data[1]); 328 alm->time.tm_hour = bcd2bin(rtc_data[2]); 329 alm->time.tm_mday = bcd2bin(rtc_data[3]); 330 alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1; 331 alm->time.tm_year = bcd2bin(rtc_data[5]) + 100; 332 333 /* report cached alarm enable state */ 334 if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) 335 alm->enabled = 1; 336 337 return ret; 338 } 339 340 static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 341 { 342 unsigned char alarm_data[ALL_TIME_REGS + 1]; 343 int ret; 344 345 ret = twl_rtc_alarm_irq_enable(dev, 0); 346 if (ret) 347 goto out; 348 349 alarm_data[1] = bin2bcd(alm->time.tm_sec); 350 alarm_data[2] = bin2bcd(alm->time.tm_min); 351 alarm_data[3] = bin2bcd(alm->time.tm_hour); 352 alarm_data[4] = bin2bcd(alm->time.tm_mday); 353 alarm_data[5] = bin2bcd(alm->time.tm_mon + 1); 354 alarm_data[6] = bin2bcd(alm->time.tm_year - 100); 355 356 /* update all the alarm registers in one shot */ 357 ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data, 358 (rtc_reg_map[REG_ALARM_SECONDS_REG]), ALL_TIME_REGS); 359 if (ret) { 360 dev_err(dev, "rtc_set_alarm error %d\n", ret); 361 goto out; 362 } 363 364 if (alm->enabled) 365 ret = twl_rtc_alarm_irq_enable(dev, 1); 366 out: 367 return ret; 368 } 369 370 static irqreturn_t twl_rtc_interrupt(int irq, void *rtc) 371 { 372 unsigned long events = 0; 373 int ret = IRQ_NONE; 374 int res; 375 u8 rd_reg; 376 377 #ifdef CONFIG_LOCKDEP 378 /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which 379 * we don't want and can't tolerate. Although it might be 380 * friendlier not to borrow this thread context... 381 */ 382 local_irq_enable(); 383 #endif 384 385 res = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG); 386 if (res) 387 goto out; 388 /* 389 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG. 390 * only one (ALARM or RTC) interrupt source may be enabled 391 * at time, we also could check our results 392 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM] 393 */ 394 if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M) 395 events |= RTC_IRQF | RTC_AF; 396 else 397 events |= RTC_IRQF | RTC_UF; 398 399 res = twl_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M, 400 REG_RTC_STATUS_REG); 401 if (res) 402 goto out; 403 404 if (twl_class_is_4030()) { 405 /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1 406 * needs 2 reads to clear the interrupt. One read is done in 407 * do_twl_pwrirq(). Doing the second read, to clear 408 * the bit. 409 * 410 * FIXME the reason PWR_ISR1 needs an extra read is that 411 * RTC_IF retriggered until we cleared REG_ALARM_M above. 412 * But re-reading like this is a bad hack; by doing so we 413 * risk wrongly clearing status for some other IRQ (losing 414 * the interrupt). Be smarter about handling RTC_UF ... 415 */ 416 res = twl_i2c_read_u8(TWL4030_MODULE_INT, 417 &rd_reg, TWL4030_INT_PWR_ISR1); 418 if (res) 419 goto out; 420 } 421 422 /* Notify RTC core on event */ 423 rtc_update_irq(rtc, 1, events); 424 425 ret = IRQ_HANDLED; 426 out: 427 return ret; 428 } 429 430 static struct rtc_class_ops twl_rtc_ops = { 431 .read_time = twl_rtc_read_time, 432 .set_time = twl_rtc_set_time, 433 .read_alarm = twl_rtc_read_alarm, 434 .set_alarm = twl_rtc_set_alarm, 435 .alarm_irq_enable = twl_rtc_alarm_irq_enable, 436 .update_irq_enable = twl_rtc_update_irq_enable, 437 }; 438 439 /*----------------------------------------------------------------------*/ 440 441 static int __devinit twl_rtc_probe(struct platform_device *pdev) 442 { 443 struct rtc_device *rtc; 444 int ret = 0; 445 int irq = platform_get_irq(pdev, 0); 446 u8 rd_reg; 447 448 if (irq <= 0) 449 return -EINVAL; 450 451 rtc = rtc_device_register(pdev->name, 452 &pdev->dev, &twl_rtc_ops, THIS_MODULE); 453 if (IS_ERR(rtc)) { 454 ret = PTR_ERR(rtc); 455 dev_err(&pdev->dev, "can't register RTC device, err %ld\n", 456 PTR_ERR(rtc)); 457 goto out0; 458 459 } 460 461 platform_set_drvdata(pdev, rtc); 462 463 ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG); 464 if (ret < 0) 465 goto out1; 466 467 if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M) 468 dev_warn(&pdev->dev, "Power up reset detected.\n"); 469 470 if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M) 471 dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n"); 472 473 /* Clear RTC Power up reset and pending alarm interrupts */ 474 ret = twl_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG); 475 if (ret < 0) 476 goto out1; 477 478 ret = request_irq(irq, twl_rtc_interrupt, 479 IRQF_TRIGGER_RISING, 480 dev_name(&rtc->dev), rtc); 481 if (ret < 0) { 482 dev_err(&pdev->dev, "IRQ is not free.\n"); 483 goto out1; 484 } 485 486 if (twl_class_is_6030()) { 487 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK, 488 REG_INT_MSK_LINE_A); 489 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK, 490 REG_INT_MSK_STS_A); 491 } 492 493 /* Check RTC module status, Enable if it is off */ 494 ret = twl_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG); 495 if (ret < 0) 496 goto out2; 497 498 if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) { 499 dev_info(&pdev->dev, "Enabling TWL-RTC.\n"); 500 rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M; 501 ret = twl_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG); 502 if (ret < 0) 503 goto out2; 504 } 505 506 /* init cached IRQ enable bits */ 507 ret = twl_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG); 508 if (ret < 0) 509 goto out2; 510 511 return ret; 512 513 out2: 514 free_irq(irq, rtc); 515 out1: 516 rtc_device_unregister(rtc); 517 out0: 518 return ret; 519 } 520 521 /* 522 * Disable all TWL RTC module interrupts. 523 * Sets status flag to free. 524 */ 525 static int __devexit twl_rtc_remove(struct platform_device *pdev) 526 { 527 /* leave rtc running, but disable irqs */ 528 struct rtc_device *rtc = platform_get_drvdata(pdev); 529 int irq = platform_get_irq(pdev, 0); 530 531 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); 532 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); 533 if (twl_class_is_6030()) { 534 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK, 535 REG_INT_MSK_LINE_A); 536 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK, 537 REG_INT_MSK_STS_A); 538 } 539 540 541 free_irq(irq, rtc); 542 543 rtc_device_unregister(rtc); 544 platform_set_drvdata(pdev, NULL); 545 return 0; 546 } 547 548 static void twl_rtc_shutdown(struct platform_device *pdev) 549 { 550 /* mask timer interrupts, but leave alarm interrupts on to enable 551 power-on when alarm is triggered */ 552 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); 553 } 554 555 #ifdef CONFIG_PM 556 557 static unsigned char irqstat; 558 559 static int twl_rtc_suspend(struct platform_device *pdev, pm_message_t state) 560 { 561 irqstat = rtc_irq_bits; 562 563 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); 564 return 0; 565 } 566 567 static int twl_rtc_resume(struct platform_device *pdev) 568 { 569 set_rtc_irq_bit(irqstat); 570 return 0; 571 } 572 573 #else 574 #define twl_rtc_suspend NULL 575 #define twl_rtc_resume NULL 576 #endif 577 578 MODULE_ALIAS("platform:twl_rtc"); 579 580 static struct platform_driver twl4030rtc_driver = { 581 .probe = twl_rtc_probe, 582 .remove = __devexit_p(twl_rtc_remove), 583 .shutdown = twl_rtc_shutdown, 584 .suspend = twl_rtc_suspend, 585 .resume = twl_rtc_resume, 586 .driver = { 587 .owner = THIS_MODULE, 588 .name = "twl_rtc", 589 }, 590 }; 591 592 static int __init twl_rtc_init(void) 593 { 594 if (twl_class_is_4030()) 595 rtc_reg_map = (u8 *) twl4030_rtc_reg_map; 596 else 597 rtc_reg_map = (u8 *) twl6030_rtc_reg_map; 598 599 return platform_driver_register(&twl4030rtc_driver); 600 } 601 module_init(twl_rtc_init); 602 603 static void __exit twl_rtc_exit(void) 604 { 605 platform_driver_unregister(&twl4030rtc_driver); 606 } 607 module_exit(twl_rtc_exit); 608 609 MODULE_AUTHOR("Texas Instruments, MontaVista Software"); 610 MODULE_LICENSE("GPL"); 611