1 /* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. 2 * 3 * This program is free software; you can redistribute it and/or modify 4 * it under the terms of the GNU General Public License version 2 and 5 * only version 2 as published by the Free Software Foundation. 6 * 7 * This program is distributed in the hope that it will be useful, 8 * but WITHOUT ANY WARRANTY; without even the implied warranty of 9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 * GNU General Public License for more details. 11 */ 12 #include <linux/of.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/rtc.h> 16 #include <linux/platform_device.h> 17 #include <linux/pm.h> 18 #include <linux/regmap.h> 19 #include <linux/slab.h> 20 #include <linux/spinlock.h> 21 22 /* RTC Register offsets from RTC CTRL REG */ 23 #define PM8XXX_ALARM_CTRL_OFFSET 0x01 24 #define PM8XXX_RTC_WRITE_OFFSET 0x02 25 #define PM8XXX_RTC_READ_OFFSET 0x06 26 #define PM8XXX_ALARM_RW_OFFSET 0x0A 27 28 /* RTC_CTRL register bit fields */ 29 #define PM8xxx_RTC_ENABLE BIT(7) 30 #define PM8xxx_RTC_ALARM_CLEAR BIT(0) 31 32 #define NUM_8_BIT_RTC_REGS 0x4 33 34 /** 35 * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions 36 * @ctrl: base address of control register 37 * @write: base address of write register 38 * @read: base address of read register 39 * @alarm_ctrl: base address of alarm control register 40 * @alarm_ctrl2: base address of alarm control2 register 41 * @alarm_rw: base address of alarm read-write register 42 * @alarm_en: alarm enable mask 43 */ 44 struct pm8xxx_rtc_regs { 45 unsigned int ctrl; 46 unsigned int write; 47 unsigned int read; 48 unsigned int alarm_ctrl; 49 unsigned int alarm_ctrl2; 50 unsigned int alarm_rw; 51 unsigned int alarm_en; 52 }; 53 54 /** 55 * struct pm8xxx_rtc - rtc driver internal structure 56 * @rtc: rtc device for this driver. 57 * @regmap: regmap used to access RTC registers 58 * @allow_set_time: indicates whether writing to the RTC is allowed 59 * @rtc_alarm_irq: rtc alarm irq number. 60 * @ctrl_reg: rtc control register. 61 * @rtc_dev: device structure. 62 * @ctrl_reg_lock: spinlock protecting access to ctrl_reg. 63 */ 64 struct pm8xxx_rtc { 65 struct rtc_device *rtc; 66 struct regmap *regmap; 67 bool allow_set_time; 68 int rtc_alarm_irq; 69 const struct pm8xxx_rtc_regs *regs; 70 struct device *rtc_dev; 71 spinlock_t ctrl_reg_lock; 72 }; 73 74 /* 75 * Steps to write the RTC registers. 76 * 1. Disable alarm if enabled. 77 * 2. Write 0x00 to LSB. 78 * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0]. 79 * 4. Enable alarm if disabled in step 1. 80 */ 81 static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) 82 { 83 int rc, i; 84 unsigned long secs, irq_flags; 85 u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0; 86 unsigned int ctrl_reg; 87 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 88 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 89 90 if (!rtc_dd->allow_set_time) 91 return -EACCES; 92 93 rtc_tm_to_time(tm, &secs); 94 95 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) { 96 value[i] = secs & 0xFF; 97 secs >>= 8; 98 } 99 100 dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs); 101 102 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 103 104 rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg); 105 if (rc) 106 goto rtc_rw_fail; 107 108 if (ctrl_reg & regs->alarm_en) { 109 alarm_enabled = 1; 110 ctrl_reg &= ~regs->alarm_en; 111 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg); 112 if (rc) { 113 dev_err(dev, "Write to RTC control register failed\n"); 114 goto rtc_rw_fail; 115 } 116 } 117 118 /* Write 0 to Byte[0] */ 119 rc = regmap_write(rtc_dd->regmap, regs->write, 0); 120 if (rc) { 121 dev_err(dev, "Write to RTC write data register failed\n"); 122 goto rtc_rw_fail; 123 } 124 125 /* Write Byte[1], Byte[2], Byte[3] */ 126 rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1, 127 &value[1], sizeof(value) - 1); 128 if (rc) { 129 dev_err(dev, "Write to RTC write data register failed\n"); 130 goto rtc_rw_fail; 131 } 132 133 /* Write Byte[0] */ 134 rc = regmap_write(rtc_dd->regmap, regs->write, value[0]); 135 if (rc) { 136 dev_err(dev, "Write to RTC write data register failed\n"); 137 goto rtc_rw_fail; 138 } 139 140 if (alarm_enabled) { 141 ctrl_reg |= regs->alarm_en; 142 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg); 143 if (rc) { 144 dev_err(dev, "Write to RTC control register failed\n"); 145 goto rtc_rw_fail; 146 } 147 } 148 149 rtc_rw_fail: 150 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 151 152 return rc; 153 } 154 155 static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm) 156 { 157 int rc; 158 u8 value[NUM_8_BIT_RTC_REGS]; 159 unsigned long secs; 160 unsigned int reg; 161 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 162 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 163 164 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value)); 165 if (rc) { 166 dev_err(dev, "RTC read data register failed\n"); 167 return rc; 168 } 169 170 /* 171 * Read the LSB again and check if there has been a carry over. 172 * If there is, redo the read operation. 173 */ 174 rc = regmap_read(rtc_dd->regmap, regs->read, ®); 175 if (rc < 0) { 176 dev_err(dev, "RTC read data register failed\n"); 177 return rc; 178 } 179 180 if (unlikely(reg < value[0])) { 181 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, 182 value, sizeof(value)); 183 if (rc) { 184 dev_err(dev, "RTC read data register failed\n"); 185 return rc; 186 } 187 } 188 189 secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24); 190 191 rtc_time_to_tm(secs, tm); 192 193 rc = rtc_valid_tm(tm); 194 if (rc < 0) { 195 dev_err(dev, "Invalid time read from RTC\n"); 196 return rc; 197 } 198 199 dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n", 200 secs, tm->tm_hour, tm->tm_min, tm->tm_sec, 201 tm->tm_mday, tm->tm_mon, tm->tm_year); 202 203 return 0; 204 } 205 206 static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 207 { 208 int rc, i; 209 u8 value[NUM_8_BIT_RTC_REGS]; 210 unsigned int ctrl_reg; 211 unsigned long secs, irq_flags; 212 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 213 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 214 215 rtc_tm_to_time(&alarm->time, &secs); 216 217 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) { 218 value[i] = secs & 0xFF; 219 secs >>= 8; 220 } 221 222 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 223 224 rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, 225 sizeof(value)); 226 if (rc) { 227 dev_err(dev, "Write to RTC ALARM register failed\n"); 228 goto rtc_rw_fail; 229 } 230 231 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 232 if (rc) 233 goto rtc_rw_fail; 234 235 if (alarm->enabled) 236 ctrl_reg |= regs->alarm_en; 237 else 238 ctrl_reg &= ~regs->alarm_en; 239 240 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 241 if (rc) { 242 dev_err(dev, "Write to RTC alarm control register failed\n"); 243 goto rtc_rw_fail; 244 } 245 246 dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n", 247 alarm->time.tm_hour, alarm->time.tm_min, 248 alarm->time.tm_sec, alarm->time.tm_mday, 249 alarm->time.tm_mon, alarm->time.tm_year); 250 rtc_rw_fail: 251 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 252 return rc; 253 } 254 255 static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 256 { 257 int rc; 258 u8 value[NUM_8_BIT_RTC_REGS]; 259 unsigned long secs; 260 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 261 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 262 263 rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value, 264 sizeof(value)); 265 if (rc) { 266 dev_err(dev, "RTC alarm time read failed\n"); 267 return rc; 268 } 269 270 secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24); 271 272 rtc_time_to_tm(secs, &alarm->time); 273 274 rc = rtc_valid_tm(&alarm->time); 275 if (rc < 0) { 276 dev_err(dev, "Invalid alarm time read from RTC\n"); 277 return rc; 278 } 279 280 dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n", 281 alarm->time.tm_hour, alarm->time.tm_min, 282 alarm->time.tm_sec, alarm->time.tm_mday, 283 alarm->time.tm_mon, alarm->time.tm_year); 284 285 return 0; 286 } 287 288 static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) 289 { 290 int rc; 291 unsigned long irq_flags; 292 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 293 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 294 unsigned int ctrl_reg; 295 296 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 297 298 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 299 if (rc) 300 goto rtc_rw_fail; 301 302 if (enable) 303 ctrl_reg |= regs->alarm_en; 304 else 305 ctrl_reg &= ~regs->alarm_en; 306 307 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 308 if (rc) { 309 dev_err(dev, "Write to RTC control register failed\n"); 310 goto rtc_rw_fail; 311 } 312 313 rtc_rw_fail: 314 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 315 return rc; 316 } 317 318 static const struct rtc_class_ops pm8xxx_rtc_ops = { 319 .read_time = pm8xxx_rtc_read_time, 320 .set_time = pm8xxx_rtc_set_time, 321 .set_alarm = pm8xxx_rtc_set_alarm, 322 .read_alarm = pm8xxx_rtc_read_alarm, 323 .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable, 324 }; 325 326 static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id) 327 { 328 struct pm8xxx_rtc *rtc_dd = dev_id; 329 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 330 unsigned int ctrl_reg; 331 int rc; 332 unsigned long irq_flags; 333 334 rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF); 335 336 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 337 338 /* Clear the alarm enable bit */ 339 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 340 if (rc) { 341 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 342 goto rtc_alarm_handled; 343 } 344 345 ctrl_reg &= ~regs->alarm_en; 346 347 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 348 if (rc) { 349 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 350 dev_err(rtc_dd->rtc_dev, 351 "Write to alarm control register failed\n"); 352 goto rtc_alarm_handled; 353 } 354 355 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 356 357 /* Clear RTC alarm register */ 358 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl2, &ctrl_reg); 359 if (rc) { 360 dev_err(rtc_dd->rtc_dev, 361 "RTC Alarm control2 register read failed\n"); 362 goto rtc_alarm_handled; 363 } 364 365 ctrl_reg |= PM8xxx_RTC_ALARM_CLEAR; 366 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl2, ctrl_reg); 367 if (rc) 368 dev_err(rtc_dd->rtc_dev, 369 "Write to RTC Alarm control2 register failed\n"); 370 371 rtc_alarm_handled: 372 return IRQ_HANDLED; 373 } 374 375 static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd) 376 { 377 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 378 unsigned int ctrl_reg; 379 int rc; 380 381 /* Check if the RTC is on, else turn it on */ 382 rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg); 383 if (rc) 384 return rc; 385 386 if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) { 387 ctrl_reg |= PM8xxx_RTC_ENABLE; 388 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg); 389 if (rc) 390 return rc; 391 } 392 393 return 0; 394 } 395 396 static const struct pm8xxx_rtc_regs pm8921_regs = { 397 .ctrl = 0x11d, 398 .write = 0x11f, 399 .read = 0x123, 400 .alarm_rw = 0x127, 401 .alarm_ctrl = 0x11d, 402 .alarm_ctrl2 = 0x11e, 403 .alarm_en = BIT(1), 404 }; 405 406 static const struct pm8xxx_rtc_regs pm8058_regs = { 407 .ctrl = 0x1e8, 408 .write = 0x1ea, 409 .read = 0x1ee, 410 .alarm_rw = 0x1f2, 411 .alarm_ctrl = 0x1e8, 412 .alarm_ctrl2 = 0x1e9, 413 .alarm_en = BIT(1), 414 }; 415 416 static const struct pm8xxx_rtc_regs pm8941_regs = { 417 .ctrl = 0x6046, 418 .write = 0x6040, 419 .read = 0x6048, 420 .alarm_rw = 0x6140, 421 .alarm_ctrl = 0x6146, 422 .alarm_ctrl2 = 0x6148, 423 .alarm_en = BIT(7), 424 }; 425 426 /* 427 * Hardcoded RTC bases until IORESOURCE_REG mapping is figured out 428 */ 429 static const struct of_device_id pm8xxx_id_table[] = { 430 { .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs }, 431 { .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs }, 432 { .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs }, 433 { }, 434 }; 435 MODULE_DEVICE_TABLE(of, pm8xxx_id_table); 436 437 static int pm8xxx_rtc_probe(struct platform_device *pdev) 438 { 439 int rc; 440 struct pm8xxx_rtc *rtc_dd; 441 const struct of_device_id *match; 442 443 match = of_match_node(pm8xxx_id_table, pdev->dev.of_node); 444 if (!match) 445 return -ENXIO; 446 447 rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL); 448 if (rtc_dd == NULL) 449 return -ENOMEM; 450 451 /* Initialise spinlock to protect RTC control register */ 452 spin_lock_init(&rtc_dd->ctrl_reg_lock); 453 454 rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL); 455 if (!rtc_dd->regmap) { 456 dev_err(&pdev->dev, "Parent regmap unavailable.\n"); 457 return -ENXIO; 458 } 459 460 rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0); 461 if (rtc_dd->rtc_alarm_irq < 0) { 462 dev_err(&pdev->dev, "Alarm IRQ resource absent!\n"); 463 return -ENXIO; 464 } 465 466 rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node, 467 "allow-set-time"); 468 469 rtc_dd->regs = match->data; 470 rtc_dd->rtc_dev = &pdev->dev; 471 472 rc = pm8xxx_rtc_enable(rtc_dd); 473 if (rc) 474 return rc; 475 476 platform_set_drvdata(pdev, rtc_dd); 477 478 device_init_wakeup(&pdev->dev, 1); 479 480 /* Register the RTC device */ 481 rtc_dd->rtc = devm_rtc_device_register(&pdev->dev, "pm8xxx_rtc", 482 &pm8xxx_rtc_ops, THIS_MODULE); 483 if (IS_ERR(rtc_dd->rtc)) { 484 dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n", 485 __func__, PTR_ERR(rtc_dd->rtc)); 486 return PTR_ERR(rtc_dd->rtc); 487 } 488 489 /* Request the alarm IRQ */ 490 rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->rtc_alarm_irq, 491 pm8xxx_alarm_trigger, 492 IRQF_TRIGGER_RISING, 493 "pm8xxx_rtc_alarm", rtc_dd); 494 if (rc < 0) { 495 dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc); 496 return rc; 497 } 498 499 dev_dbg(&pdev->dev, "Probe success !!\n"); 500 501 return 0; 502 } 503 504 #ifdef CONFIG_PM_SLEEP 505 static int pm8xxx_rtc_resume(struct device *dev) 506 { 507 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 508 509 if (device_may_wakeup(dev)) 510 disable_irq_wake(rtc_dd->rtc_alarm_irq); 511 512 return 0; 513 } 514 515 static int pm8xxx_rtc_suspend(struct device *dev) 516 { 517 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 518 519 if (device_may_wakeup(dev)) 520 enable_irq_wake(rtc_dd->rtc_alarm_irq); 521 522 return 0; 523 } 524 #endif 525 526 static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops, 527 pm8xxx_rtc_suspend, 528 pm8xxx_rtc_resume); 529 530 static struct platform_driver pm8xxx_rtc_driver = { 531 .probe = pm8xxx_rtc_probe, 532 .driver = { 533 .name = "rtc-pm8xxx", 534 .pm = &pm8xxx_rtc_pm_ops, 535 .of_match_table = pm8xxx_id_table, 536 }, 537 }; 538 539 module_platform_driver(pm8xxx_rtc_driver); 540 541 MODULE_ALIAS("platform:rtc-pm8xxx"); 542 MODULE_DESCRIPTION("PMIC8xxx RTC driver"); 543 MODULE_LICENSE("GPL v2"); 544 MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>"); 545