1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * pm8xxx RTC driver 4 * 5 * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. 6 * Copyright (c) 2023, Linaro Limited 7 */ 8#include <linux/of.h> 9#include <linux/module.h> 10#include <linux/nvmem-consumer.h> 11#include <linux/init.h> 12#include <linux/rtc.h> 13#include <linux/platform_device.h> 14#include <linux/pm.h> 15#include <linux/pm_wakeirq.h> 16#include <linux/regmap.h> 17#include <linux/slab.h> 18#include <linux/spinlock.h> 19 20#include <asm/unaligned.h> 21 22/* RTC_CTRL register bit fields */ 23#define PM8xxx_RTC_ENABLE BIT(7) 24#define PM8xxx_RTC_ALARM_CLEAR BIT(0) 25#define PM8xxx_RTC_ALARM_ENABLE BIT(7) 26 27#define NUM_8_BIT_RTC_REGS 0x4 28 29/** 30 * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions 31 * @ctrl: address of control register 32 * @write: base address of write registers 33 * @read: base address of read registers 34 * @alarm_ctrl: address of alarm control register 35 * @alarm_ctrl2: address of alarm control2 register 36 * @alarm_rw: base address of alarm read-write registers 37 * @alarm_en: alarm enable mask 38 */ 39struct pm8xxx_rtc_regs { 40 unsigned int ctrl; 41 unsigned int write; 42 unsigned int read; 43 unsigned int alarm_ctrl; 44 unsigned int alarm_ctrl2; 45 unsigned int alarm_rw; 46 unsigned int alarm_en; 47}; 48 49/** 50 * struct pm8xxx_rtc - RTC driver internal structure 51 * @rtc: RTC device 52 * @regmap: regmap used to access registers 53 * @allow_set_time: whether the time can be set 54 * @alarm_irq: alarm irq number 55 * @regs: register description 56 * @dev: device structure 57 * @nvmem_cell: nvmem cell for offset 58 * @offset: offset from epoch in seconds 59 */ 60struct pm8xxx_rtc { 61 struct rtc_device *rtc; 62 struct regmap *regmap; 63 bool allow_set_time; 64 int alarm_irq; 65 const struct pm8xxx_rtc_regs *regs; 66 struct device *dev; 67 struct nvmem_cell *nvmem_cell; 68 u32 offset; 69}; 70 71static int pm8xxx_rtc_read_nvmem_offset(struct pm8xxx_rtc *rtc_dd) 72{ 73 size_t len; 74 void *buf; 75 int rc; 76 77 buf = nvmem_cell_read(rtc_dd->nvmem_cell, &len); 78 if (IS_ERR(buf)) { 79 rc = PTR_ERR(buf); 80 dev_dbg(rtc_dd->dev, "failed to read nvmem offset: %d\n", rc); 81 return rc; 82 } 83 84 if (len != sizeof(u32)) { 85 dev_dbg(rtc_dd->dev, "unexpected nvmem cell size %zu\n", len); 86 kfree(buf); 87 return -EINVAL; 88 } 89 90 rtc_dd->offset = get_unaligned_le32(buf); 91 92 kfree(buf); 93 94 return 0; 95} 96 97static int pm8xxx_rtc_write_nvmem_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) 98{ 99 u8 buf[sizeof(u32)]; 100 int rc; 101 102 put_unaligned_le32(offset, buf); 103 104 rc = nvmem_cell_write(rtc_dd->nvmem_cell, buf, sizeof(buf)); 105 if (rc < 0) { 106 dev_dbg(rtc_dd->dev, "failed to write nvmem offset: %d\n", rc); 107 return rc; 108 } 109 110 return 0; 111} 112 113static int pm8xxx_rtc_read_offset(struct pm8xxx_rtc *rtc_dd) 114{ 115 if (!rtc_dd->nvmem_cell) 116 return 0; 117 118 return pm8xxx_rtc_read_nvmem_offset(rtc_dd); 119} 120 121static int pm8xxx_rtc_read_raw(struct pm8xxx_rtc *rtc_dd, u32 *secs) 122{ 123 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 124 u8 value[NUM_8_BIT_RTC_REGS]; 125 unsigned int reg; 126 int rc; 127 128 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value)); 129 if (rc) 130 return rc; 131 132 /* 133 * Read the LSB again and check if there has been a carry over. 134 * If there has, redo the read operation. 135 */ 136 rc = regmap_read(rtc_dd->regmap, regs->read, ®); 137 if (rc < 0) 138 return rc; 139 140 if (reg < value[0]) { 141 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, 142 sizeof(value)); 143 if (rc) 144 return rc; 145 } 146 147 *secs = get_unaligned_le32(value); 148 149 return 0; 150} 151 152static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs) 153{ 154 u32 raw_secs; 155 u32 offset; 156 int rc; 157 158 if (!rtc_dd->nvmem_cell) 159 return -ENODEV; 160 161 rc = pm8xxx_rtc_read_raw(rtc_dd, &raw_secs); 162 if (rc) 163 return rc; 164 165 offset = secs - raw_secs; 166 167 if (offset == rtc_dd->offset) 168 return 0; 169 170 rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset); 171 if (rc) 172 return rc; 173 174 rtc_dd->offset = offset; 175 176 return 0; 177} 178 179/* 180 * Steps to write the RTC registers. 181 * 1. Disable alarm if enabled. 182 * 2. Disable rtc if enabled. 183 * 3. Write 0x00 to LSB. 184 * 4. Write Byte[1], Byte[2], Byte[3] then Byte[0]. 185 * 5. Enable rtc if disabled in step 2. 186 * 6. Enable alarm if disabled in step 1. 187 */ 188static int __pm8xxx_rtc_set_time(struct pm8xxx_rtc *rtc_dd, u32 secs) 189{ 190 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 191 u8 value[NUM_8_BIT_RTC_REGS]; 192 bool alarm_enabled; 193 int rc; 194 195 put_unaligned_le32(secs, value); 196 197 rc = regmap_update_bits_check(rtc_dd->regmap, regs->alarm_ctrl, 198 regs->alarm_en, 0, &alarm_enabled); 199 if (rc) 200 return rc; 201 202 /* Disable RTC */ 203 rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 0); 204 if (rc) 205 return rc; 206 207 /* Write 0 to Byte[0] */ 208 rc = regmap_write(rtc_dd->regmap, regs->write, 0); 209 if (rc) 210 return rc; 211 212 /* Write Byte[1], Byte[2], Byte[3] */ 213 rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1, 214 &value[1], sizeof(value) - 1); 215 if (rc) 216 return rc; 217 218 /* Write Byte[0] */ 219 rc = regmap_write(rtc_dd->regmap, regs->write, value[0]); 220 if (rc) 221 return rc; 222 223 /* Enable RTC */ 224 rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 225 PM8xxx_RTC_ENABLE); 226 if (rc) 227 return rc; 228 229 if (alarm_enabled) { 230 rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, 231 regs->alarm_en, regs->alarm_en); 232 if (rc) 233 return rc; 234 } 235 236 return 0; 237} 238 239static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) 240{ 241 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 242 u32 secs; 243 int rc; 244 245 secs = rtc_tm_to_time64(tm); 246 247 if (rtc_dd->allow_set_time) 248 rc = __pm8xxx_rtc_set_time(rtc_dd, secs); 249 else 250 rc = pm8xxx_rtc_update_offset(rtc_dd, secs); 251 252 if (rc) 253 return rc; 254 255 dev_dbg(dev, "set time: %ptRd %ptRt (%u + %u)\n", tm, tm, 256 secs - rtc_dd->offset, rtc_dd->offset); 257 return 0; 258} 259 260static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm) 261{ 262 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 263 u32 secs; 264 int rc; 265 266 rc = pm8xxx_rtc_read_raw(rtc_dd, &secs); 267 if (rc) 268 return rc; 269 270 secs += rtc_dd->offset; 271 rtc_time64_to_tm(secs, tm); 272 273 dev_dbg(dev, "read time: %ptRd %ptRt (%u + %u)\n", tm, tm, 274 secs - rtc_dd->offset, rtc_dd->offset); 275 return 0; 276} 277 278static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 279{ 280 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 281 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 282 u8 value[NUM_8_BIT_RTC_REGS]; 283 u32 secs; 284 int rc; 285 286 secs = rtc_tm_to_time64(&alarm->time); 287 secs -= rtc_dd->offset; 288 put_unaligned_le32(secs, value); 289 290 rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, 291 regs->alarm_en, 0); 292 if (rc) 293 return rc; 294 295 rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, 296 sizeof(value)); 297 if (rc) 298 return rc; 299 300 if (alarm->enabled) { 301 rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, 302 regs->alarm_en, regs->alarm_en); 303 if (rc) 304 return rc; 305 } 306 307 dev_dbg(dev, "set alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time); 308 309 return 0; 310} 311 312static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 313{ 314 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 315 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 316 u8 value[NUM_8_BIT_RTC_REGS]; 317 unsigned int ctrl_reg; 318 u32 secs; 319 int rc; 320 321 rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value, 322 sizeof(value)); 323 if (rc) 324 return rc; 325 326 secs = get_unaligned_le32(value); 327 secs += rtc_dd->offset; 328 rtc_time64_to_tm(secs, &alarm->time); 329 330 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); 331 if (rc) 332 return rc; 333 334 alarm->enabled = !!(ctrl_reg & PM8xxx_RTC_ALARM_ENABLE); 335 336 dev_dbg(dev, "read alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time); 337 338 return 0; 339} 340 341static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) 342{ 343 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); 344 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 345 u8 value[NUM_8_BIT_RTC_REGS] = {0}; 346 unsigned int val; 347 int rc; 348 349 if (enable) 350 val = regs->alarm_en; 351 else 352 val = 0; 353 354 rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, 355 regs->alarm_en, val); 356 if (rc) 357 return rc; 358 359 /* Clear alarm register */ 360 if (!enable) { 361 rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, 362 sizeof(value)); 363 if (rc) 364 return rc; 365 } 366 367 return 0; 368} 369 370static const struct rtc_class_ops pm8xxx_rtc_ops = { 371 .read_time = pm8xxx_rtc_read_time, 372 .set_time = pm8xxx_rtc_set_time, 373 .set_alarm = pm8xxx_rtc_set_alarm, 374 .read_alarm = pm8xxx_rtc_read_alarm, 375 .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable, 376}; 377 378static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id) 379{ 380 struct pm8xxx_rtc *rtc_dd = dev_id; 381 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 382 int rc; 383 384 rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF); 385 386 /* Disable alarm */ 387 rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, 388 regs->alarm_en, 0); 389 if (rc) 390 return IRQ_NONE; 391 392 /* Clear alarm status */ 393 rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl2, 394 PM8xxx_RTC_ALARM_CLEAR, 0); 395 if (rc) 396 return IRQ_NONE; 397 398 return IRQ_HANDLED; 399} 400 401static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd) 402{ 403 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; 404 405 return regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 406 PM8xxx_RTC_ENABLE); 407} 408 409static const struct pm8xxx_rtc_regs pm8921_regs = { 410 .ctrl = 0x11d, 411 .write = 0x11f, 412 .read = 0x123, 413 .alarm_rw = 0x127, 414 .alarm_ctrl = 0x11d, 415 .alarm_ctrl2 = 0x11e, 416 .alarm_en = BIT(1), 417}; 418 419static const struct pm8xxx_rtc_regs pm8058_regs = { 420 .ctrl = 0x1e8, 421 .write = 0x1ea, 422 .read = 0x1ee, 423 .alarm_rw = 0x1f2, 424 .alarm_ctrl = 0x1e8, 425 .alarm_ctrl2 = 0x1e9, 426 .alarm_en = BIT(1), 427}; 428 429static const struct pm8xxx_rtc_regs pm8941_regs = { 430 .ctrl = 0x6046, 431 .write = 0x6040, 432 .read = 0x6048, 433 .alarm_rw = 0x6140, 434 .alarm_ctrl = 0x6146, 435 .alarm_ctrl2 = 0x6148, 436 .alarm_en = BIT(7), 437}; 438 439static const struct pm8xxx_rtc_regs pmk8350_regs = { 440 .ctrl = 0x6146, 441 .write = 0x6140, 442 .read = 0x6148, 443 .alarm_rw = 0x6240, 444 .alarm_ctrl = 0x6246, 445 .alarm_ctrl2 = 0x6248, 446 .alarm_en = BIT(7), 447}; 448 449static const struct of_device_id pm8xxx_id_table[] = { 450 { .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs }, 451 { .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs }, 452 { .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs }, 453 { .compatible = "qcom,pmk8350-rtc", .data = &pmk8350_regs }, 454 { }, 455}; 456MODULE_DEVICE_TABLE(of, pm8xxx_id_table); 457 458static int pm8xxx_rtc_probe(struct platform_device *pdev) 459{ 460 const struct of_device_id *match; 461 struct pm8xxx_rtc *rtc_dd; 462 int rc; 463 464 match = of_match_node(pm8xxx_id_table, pdev->dev.of_node); 465 if (!match) 466 return -ENXIO; 467 468 rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL); 469 if (rtc_dd == NULL) 470 return -ENOMEM; 471 472 rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL); 473 if (!rtc_dd->regmap) 474 return -ENXIO; 475 476 rtc_dd->alarm_irq = platform_get_irq(pdev, 0); 477 if (rtc_dd->alarm_irq < 0) 478 return -ENXIO; 479 480 rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node, 481 "allow-set-time"); 482 483 rtc_dd->nvmem_cell = devm_nvmem_cell_get(&pdev->dev, "offset"); 484 if (IS_ERR(rtc_dd->nvmem_cell)) { 485 rc = PTR_ERR(rtc_dd->nvmem_cell); 486 if (rc != -ENOENT) 487 return rc; 488 rtc_dd->nvmem_cell = NULL; 489 } 490 491 rtc_dd->regs = match->data; 492 rtc_dd->dev = &pdev->dev; 493 494 if (!rtc_dd->allow_set_time) { 495 rc = pm8xxx_rtc_read_offset(rtc_dd); 496 if (rc) 497 return rc; 498 } 499 500 rc = pm8xxx_rtc_enable(rtc_dd); 501 if (rc) 502 return rc; 503 504 platform_set_drvdata(pdev, rtc_dd); 505 506 device_init_wakeup(&pdev->dev, 1); 507 508 rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev); 509 if (IS_ERR(rtc_dd->rtc)) 510 return PTR_ERR(rtc_dd->rtc); 511 512 rtc_dd->rtc->ops = &pm8xxx_rtc_ops; 513 rtc_dd->rtc->range_max = U32_MAX; 514 515 rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->alarm_irq, 516 pm8xxx_alarm_trigger, 517 IRQF_TRIGGER_RISING, 518 "pm8xxx_rtc_alarm", rtc_dd); 519 if (rc < 0) 520 return rc; 521 522 rc = devm_rtc_register_device(rtc_dd->rtc); 523 if (rc) 524 return rc; 525 526 rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq); 527 if (rc) 528 return rc; 529 530 return 0; 531} 532 533static void pm8xxx_remove(struct platform_device *pdev) 534{ 535 dev_pm_clear_wake_irq(&pdev->dev); 536} 537 538static struct platform_driver pm8xxx_rtc_driver = { 539 .probe = pm8xxx_rtc_probe, 540 .remove_new = pm8xxx_remove, 541 .driver = { 542 .name = "rtc-pm8xxx", 543 .of_match_table = pm8xxx_id_table, 544 }, 545}; 546 547module_platform_driver(pm8xxx_rtc_driver); 548 549MODULE_ALIAS("platform:rtc-pm8xxx"); 550MODULE_DESCRIPTION("PMIC8xxx RTC driver"); 551MODULE_LICENSE("GPL v2"); 552MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>"); 553MODULE_AUTHOR("Johan Hovold <johan@kernel.org>"); 554