1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. 3 */ 4 #include <linux/of.h> 5 #include <linux/module.h> 6 #include <linux/init.h> 7 #include <linux/rtc.h> 8 #include <linux/platform_device.h> 9 #include <linux/pm.h> 10 #include <linux/regmap.h> 11 #include <linux/slab.h> 12 #include <linux/spinlock.h> 13 14 /* RTC Register offsets from RTC CTRL REG */ 15 #define PM8XXX_ALARM_CTRL_OFFSET 0x01 16 #define PM8XXX_RTC_WRITE_OFFSET 0x02 17 #define PM8XXX_RTC_READ_OFFSET 0x06 18 #define PM8XXX_ALARM_RW_OFFSET 0x0A 19 20 /* RTC_CTRL register bit fields */ 21 #define PM8xxx_RTC_ENABLE BIT(7) 22 #define PM8xxx_RTC_ALARM_CLEAR BIT(0) 23 #define PM8xxx_RTC_ALARM_ENABLE BIT(7) 24 25 #define NUM_8_BIT_RTC_REGS 0x4 26 27 /** 28 * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions 29 * @ctrl: base address of control register 30 * @write: base address of write register 31 * @read: base address of read register 32 * @alarm_ctrl: base address of alarm control register 33 * @alarm_ctrl2: base address of alarm control2 register 34 * @alarm_rw: base address of alarm read-write register 35 * @alarm_en: alarm enable mask 36 */ 37 struct pm8xxx_rtc_regs { 38 unsigned int ctrl; 39 unsigned int write; 40 unsigned int read; 41 unsigned int alarm_ctrl; 42 unsigned int alarm_ctrl2; 43 unsigned int alarm_rw; 44 unsigned int alarm_en; 45 }; 46 47 /** 48 * struct pm8xxx_rtc - rtc driver internal structure 49 * @rtc: rtc device for this driver. 50 * @regmap: regmap used to access RTC registers 51 * @allow_set_time: indicates whether writing to the RTC is allowed 52 * @rtc_alarm_irq: rtc alarm irq number. 53 * @regs: rtc registers description. 54 * @rtc_dev: device structure. 55 * @ctrl_reg_lock: spinlock protecting access to ctrl_reg. 56 */ 57 struct pm8xxx_rtc { 58 struct rtc_device *rtc; 59 struct regmap *regmap; 60 bool allow_set_time; 61 int rtc_alarm_irq; 62 const struct pm8xxx_rtc_regs *regs; 63 struct device *rtc_dev; 64 spinlock_t ctrl_reg_lock; 65 }; 66 67 /* 68 * Steps to write the RTC registers. 69 * 1. Disable alarm if enabled. 70 * 2. Disable rtc if enabled. 71 * 3. Write 0x00 to LSB. 72 * 4. Write Byte[1], Byte[2], Byte[3] then Byte[0]. 73 * 5. Enable rtc if disabled in step 2. 74 * 6. Enable alarm if disabled in step 1. 75 */ 76 static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) 77 { 78 int rc, i; 79 unsigned long secs, irq_flags; 80 u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0, rtc_disabled = 0; 81 unsigned int ctrl_reg, rtc_ctrl_reg; 82 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 83 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 84 85 if (!rtc_dd->allow_set_time) 86 return -EACCES; 87 88 secs = rtc_tm_to_time64(tm); 89 90 dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs); 91 92 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) { 93 value[i] = secs & 0xFF; 94 secs >>= 8; 95 } 96 97 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 98 99 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 100 if (rc) 101 goto rtc_rw_fail; 102 103 if (ctrl_reg & regs->alarm_en) { 104 alarm_enabled = 1; 105 ctrl_reg &= ~regs->alarm_en; 106 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 107 if (rc) { 108 dev_err(dev, "Write to RTC Alarm control register failed\n"); 109 goto rtc_rw_fail; 110 } 111 } 112 113 /* Disable RTC H/w before writing on RTC register */ 114 rc = regmap_read(rtc_dd->regmap, regs->ctrl, &rtc_ctrl_reg); 115 if (rc) 116 goto rtc_rw_fail; 117 118 if (rtc_ctrl_reg & PM8xxx_RTC_ENABLE) { 119 rtc_disabled = 1; 120 rtc_ctrl_reg &= ~PM8xxx_RTC_ENABLE; 121 rc = regmap_write(rtc_dd->regmap, regs->ctrl, rtc_ctrl_reg); 122 if (rc) { 123 dev_err(dev, "Write to RTC control register failed\n"); 124 goto rtc_rw_fail; 125 } 126 } 127 128 /* Write 0 to Byte[0] */ 129 rc = regmap_write(rtc_dd->regmap, regs->write, 0); 130 if (rc) { 131 dev_err(dev, "Write to RTC write data register failed\n"); 132 goto rtc_rw_fail; 133 } 134 135 /* Write Byte[1], Byte[2], Byte[3] */ 136 rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1, 137 &value[1], sizeof(value) - 1); 138 if (rc) { 139 dev_err(dev, "Write to RTC write data register failed\n"); 140 goto rtc_rw_fail; 141 } 142 143 /* Write Byte[0] */ 144 rc = regmap_write(rtc_dd->regmap, regs->write, value[0]); 145 if (rc) { 146 dev_err(dev, "Write to RTC write data register failed\n"); 147 goto rtc_rw_fail; 148 } 149 150 /* Enable RTC H/w after writing on RTC register */ 151 if (rtc_disabled) { 152 rtc_ctrl_reg |= PM8xxx_RTC_ENABLE; 153 rc = regmap_write(rtc_dd->regmap, regs->ctrl, rtc_ctrl_reg); 154 if (rc) { 155 dev_err(dev, "Write to RTC control register failed\n"); 156 goto rtc_rw_fail; 157 } 158 } 159 160 if (alarm_enabled) { 161 ctrl_reg |= regs->alarm_en; 162 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 163 if (rc) { 164 dev_err(dev, "Write to RTC Alarm control register failed\n"); 165 goto rtc_rw_fail; 166 } 167 } 168 169 rtc_rw_fail: 170 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 171 172 return rc; 173 } 174 175 static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm) 176 { 177 int rc; 178 u8 value[NUM_8_BIT_RTC_REGS]; 179 unsigned long secs; 180 unsigned int reg; 181 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 182 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 183 184 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value)); 185 if (rc) { 186 dev_err(dev, "RTC read data register failed\n"); 187 return rc; 188 } 189 190 /* 191 * Read the LSB again and check if there has been a carry over. 192 * If there is, redo the read operation. 193 */ 194 rc = regmap_read(rtc_dd->regmap, regs->read, ®); 195 if (rc < 0) { 196 dev_err(dev, "RTC read data register failed\n"); 197 return rc; 198 } 199 200 if (unlikely(reg < value[0])) { 201 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, 202 value, sizeof(value)); 203 if (rc) { 204 dev_err(dev, "RTC read data register failed\n"); 205 return rc; 206 } 207 } 208 209 secs = value[0] | (value[1] << 8) | (value[2] << 16) | 210 ((unsigned long)value[3] << 24); 211 212 rtc_time64_to_tm(secs, tm); 213 214 dev_dbg(dev, "secs = %lu, h:m:s == %ptRt, y-m-d = %ptRdr\n", secs, tm, tm); 215 216 return 0; 217 } 218 219 static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 220 { 221 int rc, i; 222 u8 value[NUM_8_BIT_RTC_REGS]; 223 unsigned int ctrl_reg; 224 unsigned long secs, irq_flags; 225 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 226 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 227 228 secs = rtc_tm_to_time64(&alarm->time); 229 230 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) { 231 value[i] = secs & 0xFF; 232 secs >>= 8; 233 } 234 235 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 236 237 rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, 238 sizeof(value)); 239 if (rc) { 240 dev_err(dev, "Write to RTC ALARM register failed\n"); 241 goto rtc_rw_fail; 242 } 243 244 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 245 if (rc) 246 goto rtc_rw_fail; 247 248 if (alarm->enabled) 249 ctrl_reg |= regs->alarm_en; 250 else 251 ctrl_reg &= ~regs->alarm_en; 252 253 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 254 if (rc) { 255 dev_err(dev, "Write to RTC alarm control register failed\n"); 256 goto rtc_rw_fail; 257 } 258 259 dev_dbg(dev, "Alarm Set for h:m:s=%ptRt, y-m-d=%ptRdr\n", 260 &alarm->time, &alarm->time); 261 rtc_rw_fail: 262 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 263 return rc; 264 } 265 266 static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 267 { 268 int rc; 269 unsigned int ctrl_reg; 270 u8 value[NUM_8_BIT_RTC_REGS]; 271 unsigned long secs; 272 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 273 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 274 275 rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value, 276 sizeof(value)); 277 if (rc) { 278 dev_err(dev, "RTC alarm time read failed\n"); 279 return rc; 280 } 281 282 secs = value[0] | (value[1] << 8) | (value[2] << 16) | 283 ((unsigned long)value[3] << 24); 284 285 rtc_time64_to_tm(secs, &alarm->time); 286 287 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 288 if (rc) { 289 dev_err(dev, "Read from RTC alarm control register failed\n"); 290 return rc; 291 } 292 alarm->enabled = !!(ctrl_reg & PM8xxx_RTC_ALARM_ENABLE); 293 294 dev_dbg(dev, "Alarm set for - h:m:s=%ptRt, y-m-d=%ptRdr\n", 295 &alarm->time, &alarm->time); 296 297 return 0; 298 } 299 300 static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) 301 { 302 int rc; 303 unsigned long irq_flags; 304 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 305 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 306 unsigned int ctrl_reg; 307 u8 value[NUM_8_BIT_RTC_REGS] = {0}; 308 309 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); 310 311 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 312 if (rc) 313 goto rtc_rw_fail; 314 315 if (enable) 316 ctrl_reg |= regs->alarm_en; 317 else 318 ctrl_reg &= ~regs->alarm_en; 319 320 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 321 if (rc) { 322 dev_err(dev, "Write to RTC control register failed\n"); 323 goto rtc_rw_fail; 324 } 325 326 /* Clear Alarm register */ 327 if (!enable) { 328 rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, 329 sizeof(value)); 330 if (rc) { 331 dev_err(dev, "Clear RTC ALARM register failed\n"); 332 goto rtc_rw_fail; 333 } 334 } 335 336 rtc_rw_fail: 337 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); 338 return rc; 339 } 340 341 static const struct rtc_class_ops pm8xxx_rtc_ops = { 342 .read_time = pm8xxx_rtc_read_time, 343 .set_time = pm8xxx_rtc_set_time, 344 .set_alarm = pm8xxx_rtc_set_alarm, 345 .read_alarm = pm8xxx_rtc_read_alarm, 346 .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable, 347 }; 348 349 static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id) 350 { 351 struct pm8xxx_rtc *rtc_dd = dev_id; 352 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 353 unsigned int ctrl_reg; 354 int rc; 355 356 rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF); 357 358 spin_lock(&rtc_dd->ctrl_reg_lock); 359 360 /* Clear the alarm enable bit */ 361 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 362 if (rc) { 363 spin_unlock(&rtc_dd->ctrl_reg_lock); 364 goto rtc_alarm_handled; 365 } 366 367 ctrl_reg &= ~regs->alarm_en; 368 369 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); 370 if (rc) { 371 spin_unlock(&rtc_dd->ctrl_reg_lock); 372 dev_err(rtc_dd->rtc_dev, 373 "Write to alarm control register failed\n"); 374 goto rtc_alarm_handled; 375 } 376 377 spin_unlock(&rtc_dd->ctrl_reg_lock); 378 379 /* Clear RTC alarm register */ 380 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl2, &ctrl_reg); 381 if (rc) { 382 dev_err(rtc_dd->rtc_dev, 383 "RTC Alarm control2 register read failed\n"); 384 goto rtc_alarm_handled; 385 } 386 387 ctrl_reg |= PM8xxx_RTC_ALARM_CLEAR; 388 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl2, ctrl_reg); 389 if (rc) 390 dev_err(rtc_dd->rtc_dev, 391 "Write to RTC Alarm control2 register failed\n"); 392 393 rtc_alarm_handled: 394 return IRQ_HANDLED; 395 } 396 397 static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd) 398 { 399 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 400 unsigned int ctrl_reg; 401 int rc; 402 403 /* Check if the RTC is on, else turn it on */ 404 rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg); 405 if (rc) 406 return rc; 407 408 if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) { 409 ctrl_reg |= PM8xxx_RTC_ENABLE; 410 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg); 411 if (rc) 412 return rc; 413 } 414 415 return 0; 416 } 417 418 static const struct pm8xxx_rtc_regs pm8921_regs = { 419 .ctrl = 0x11d, 420 .write = 0x11f, 421 .read = 0x123, 422 .alarm_rw = 0x127, 423 .alarm_ctrl = 0x11d, 424 .alarm_ctrl2 = 0x11e, 425 .alarm_en = BIT(1), 426 }; 427 428 static const struct pm8xxx_rtc_regs pm8058_regs = { 429 .ctrl = 0x1e8, 430 .write = 0x1ea, 431 .read = 0x1ee, 432 .alarm_rw = 0x1f2, 433 .alarm_ctrl = 0x1e8, 434 .alarm_ctrl2 = 0x1e9, 435 .alarm_en = BIT(1), 436 }; 437 438 static const struct pm8xxx_rtc_regs pm8941_regs = { 439 .ctrl = 0x6046, 440 .write = 0x6040, 441 .read = 0x6048, 442 .alarm_rw = 0x6140, 443 .alarm_ctrl = 0x6146, 444 .alarm_ctrl2 = 0x6148, 445 .alarm_en = BIT(7), 446 }; 447 448 /* 449 * Hardcoded RTC bases until IORESOURCE_REG mapping is figured out 450 */ 451 static const struct of_device_id pm8xxx_id_table[] = { 452 { .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs }, 453 { .compatible = "qcom,pm8018-rtc", .data = &pm8921_regs }, 454 { .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs }, 455 { .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs }, 456 { }, 457 }; 458 MODULE_DEVICE_TABLE(of, pm8xxx_id_table); 459 460 static int pm8xxx_rtc_probe(struct platform_device *pdev) 461 { 462 int rc; 463 struct pm8xxx_rtc *rtc_dd; 464 const struct of_device_id *match; 465 466 match = of_match_node(pm8xxx_id_table, pdev->dev.of_node); 467 if (!match) 468 return -ENXIO; 469 470 rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL); 471 if (rtc_dd == NULL) 472 return -ENOMEM; 473 474 /* Initialise spinlock to protect RTC control register */ 475 spin_lock_init(&rtc_dd->ctrl_reg_lock); 476 477 rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL); 478 if (!rtc_dd->regmap) { 479 dev_err(&pdev->dev, "Parent regmap unavailable.\n"); 480 return -ENXIO; 481 } 482 483 rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0); 484 if (rtc_dd->rtc_alarm_irq < 0) 485 return -ENXIO; 486 487 rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node, 488 "allow-set-time"); 489 490 rtc_dd->regs = match->data; 491 rtc_dd->rtc_dev = &pdev->dev; 492 493 rc = pm8xxx_rtc_enable(rtc_dd); 494 if (rc) 495 return rc; 496 497 platform_set_drvdata(pdev, rtc_dd); 498 499 device_init_wakeup(&pdev->dev, 1); 500 501 /* Register the RTC device */ 502 rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev); 503 if (IS_ERR(rtc_dd->rtc)) 504 return PTR_ERR(rtc_dd->rtc); 505 506 rtc_dd->rtc->ops = &pm8xxx_rtc_ops; 507 rtc_dd->rtc->range_max = U32_MAX; 508 509 /* Request the alarm IRQ */ 510 rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->rtc_alarm_irq, 511 pm8xxx_alarm_trigger, 512 IRQF_TRIGGER_RISING, 513 "pm8xxx_rtc_alarm", rtc_dd); 514 if (rc < 0) { 515 dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc); 516 return rc; 517 } 518 519 return devm_rtc_register_device(rtc_dd->rtc); 520 } 521 522 #ifdef CONFIG_PM_SLEEP 523 static int pm8xxx_rtc_resume(struct device *dev) 524 { 525 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 526 527 if (device_may_wakeup(dev)) 528 disable_irq_wake(rtc_dd->rtc_alarm_irq); 529 530 return 0; 531 } 532 533 static int pm8xxx_rtc_suspend(struct device *dev) 534 { 535 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 536 537 if (device_may_wakeup(dev)) 538 enable_irq_wake(rtc_dd->rtc_alarm_irq); 539 540 return 0; 541 } 542 #endif 543 544 static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops, 545 pm8xxx_rtc_suspend, 546 pm8xxx_rtc_resume); 547 548 static struct platform_driver pm8xxx_rtc_driver = { 549 .probe = pm8xxx_rtc_probe, 550 .driver = { 551 .name = "rtc-pm8xxx", 552 .pm = &pm8xxx_rtc_pm_ops, 553 .of_match_table = pm8xxx_id_table, 554 }, 555 }; 556 557 module_platform_driver(pm8xxx_rtc_driver); 558 559 MODULE_ALIAS("platform:rtc-pm8xxx"); 560 MODULE_DESCRIPTION("PMIC8xxx RTC driver"); 561 MODULE_LICENSE("GPL v2"); 562 MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>"); 563