1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * rtc-tps65910.c -- TPS65910 Real Time Clock interface 4 * 5 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. 6 * Author: Venu Byravarasu <vbyravarasu@nvidia.com> 7 * 8 * Based on original TI driver rtc-twl.c 9 * Copyright (C) 2007 MontaVista Software, Inc 10 * Author: Alexandre Rusev <source@mvista.com> 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/errno.h> 15 #include <linux/init.h> 16 #include <linux/module.h> 17 #include <linux/types.h> 18 #include <linux/rtc.h> 19 #include <linux/bcd.h> 20 #include <linux/math64.h> 21 #include <linux/platform_device.h> 22 #include <linux/interrupt.h> 23 #include <linux/mfd/tps65910.h> 24 25 struct tps65910_rtc { 26 struct rtc_device *rtc; 27 int irq; 28 }; 29 30 /* Total number of RTC registers needed to set time*/ 31 #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1) 32 33 /* Total number of RTC registers needed to set compensation registers */ 34 #define NUM_COMP_REGS (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1) 35 36 /* Min and max values supported with 'offset' interface (swapped sign) */ 37 #define MIN_OFFSET (-277761) 38 #define MAX_OFFSET (277778) 39 40 /* Number of ticks per hour */ 41 #define TICKS_PER_HOUR (32768 * 3600) 42 43 /* Multiplier for ppb conversions */ 44 #define PPB_MULT (1000000000LL) 45 46 static int tps65910_rtc_alarm_irq_enable(struct device *dev, 47 unsigned int enabled) 48 { 49 struct tps65910 *tps = dev_get_drvdata(dev->parent); 50 u8 val = 0; 51 52 if (enabled) 53 val = TPS65910_RTC_INTERRUPTS_IT_ALARM; 54 55 return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val); 56 } 57 58 /* 59 * Gets current tps65910 RTC time and date parameters. 60 * 61 * The RTC's time/alarm representation is not what gmtime(3) requires 62 * Linux to use: 63 * 64 * - Months are 1..12 vs Linux 0-11 65 * - Years are 0..99 vs Linux 1900..N (we assume 21st century) 66 */ 67 static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm) 68 { 69 unsigned char rtc_data[NUM_TIME_REGS]; 70 struct tps65910 *tps = dev_get_drvdata(dev->parent); 71 int ret; 72 73 /* Copy RTC counting registers to static registers or latches */ 74 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 75 TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME); 76 if (ret < 0) { 77 dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret); 78 return ret; 79 } 80 81 ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data, 82 NUM_TIME_REGS); 83 if (ret < 0) { 84 dev_err(dev, "reading from RTC failed with err:%d\n", ret); 85 return ret; 86 } 87 88 tm->tm_sec = bcd2bin(rtc_data[0]); 89 tm->tm_min = bcd2bin(rtc_data[1]); 90 tm->tm_hour = bcd2bin(rtc_data[2]); 91 tm->tm_mday = bcd2bin(rtc_data[3]); 92 tm->tm_mon = bcd2bin(rtc_data[4]) - 1; 93 tm->tm_year = bcd2bin(rtc_data[5]) + 100; 94 95 return ret; 96 } 97 98 static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm) 99 { 100 unsigned char rtc_data[NUM_TIME_REGS]; 101 struct tps65910 *tps = dev_get_drvdata(dev->parent); 102 int ret; 103 104 rtc_data[0] = bin2bcd(tm->tm_sec); 105 rtc_data[1] = bin2bcd(tm->tm_min); 106 rtc_data[2] = bin2bcd(tm->tm_hour); 107 rtc_data[3] = bin2bcd(tm->tm_mday); 108 rtc_data[4] = bin2bcd(tm->tm_mon + 1); 109 rtc_data[5] = bin2bcd(tm->tm_year - 100); 110 111 /* Stop RTC while updating the RTC time registers */ 112 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 113 TPS65910_RTC_CTRL_STOP_RTC, 0); 114 if (ret < 0) { 115 dev_err(dev, "RTC stop failed with err:%d\n", ret); 116 return ret; 117 } 118 119 /* update all the time registers in one shot */ 120 ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data, 121 NUM_TIME_REGS); 122 if (ret < 0) { 123 dev_err(dev, "rtc_set_time error %d\n", ret); 124 return ret; 125 } 126 127 /* Start back RTC */ 128 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 129 TPS65910_RTC_CTRL_STOP_RTC, 1); 130 if (ret < 0) 131 dev_err(dev, "RTC start failed with err:%d\n", ret); 132 133 return ret; 134 } 135 136 /* 137 * Gets current tps65910 RTC alarm time. 138 */ 139 static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 140 { 141 unsigned char alarm_data[NUM_TIME_REGS]; 142 u32 int_val; 143 struct tps65910 *tps = dev_get_drvdata(dev->parent); 144 int ret; 145 146 ret = regmap_bulk_read(tps->regmap, TPS65910_ALARM_SECONDS, alarm_data, 147 NUM_TIME_REGS); 148 if (ret < 0) { 149 dev_err(dev, "rtc_read_alarm error %d\n", ret); 150 return ret; 151 } 152 153 alm->time.tm_sec = bcd2bin(alarm_data[0]); 154 alm->time.tm_min = bcd2bin(alarm_data[1]); 155 alm->time.tm_hour = bcd2bin(alarm_data[2]); 156 alm->time.tm_mday = bcd2bin(alarm_data[3]); 157 alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; 158 alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; 159 160 ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val); 161 if (ret < 0) 162 return ret; 163 164 if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM) 165 alm->enabled = 1; 166 167 return ret; 168 } 169 170 static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 171 { 172 unsigned char alarm_data[NUM_TIME_REGS]; 173 struct tps65910 *tps = dev_get_drvdata(dev->parent); 174 int ret; 175 176 ret = tps65910_rtc_alarm_irq_enable(dev, 0); 177 if (ret) 178 return ret; 179 180 alarm_data[0] = bin2bcd(alm->time.tm_sec); 181 alarm_data[1] = bin2bcd(alm->time.tm_min); 182 alarm_data[2] = bin2bcd(alm->time.tm_hour); 183 alarm_data[3] = bin2bcd(alm->time.tm_mday); 184 alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); 185 alarm_data[5] = bin2bcd(alm->time.tm_year - 100); 186 187 /* update all the alarm registers in one shot */ 188 ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS, 189 alarm_data, NUM_TIME_REGS); 190 if (ret) { 191 dev_err(dev, "rtc_set_alarm error %d\n", ret); 192 return ret; 193 } 194 195 if (alm->enabled) 196 ret = tps65910_rtc_alarm_irq_enable(dev, 1); 197 198 return ret; 199 } 200 201 static int tps65910_rtc_set_calibration(struct device *dev, int calibration) 202 { 203 unsigned char comp_data[NUM_COMP_REGS]; 204 struct tps65910 *tps = dev_get_drvdata(dev->parent); 205 s16 value; 206 int ret; 207 208 /* 209 * TPS65910 uses two's complement 16 bit value for compensation for RTC 210 * crystal inaccuracies. One time every hour when seconds counter 211 * increments from 0 to 1 compensation value will be added to internal 212 * RTC counter value. 213 * 214 * Compensation value 0x7FFF is prohibited value. 215 * 216 * Valid range for compensation value: [-32768 .. 32766] 217 */ 218 if ((calibration < -32768) || (calibration > 32766)) { 219 dev_err(dev, "RTC calibration value out of range: %d\n", 220 calibration); 221 return -EINVAL; 222 } 223 224 value = (s16)calibration; 225 226 comp_data[0] = (u16)value & 0xFF; 227 comp_data[1] = ((u16)value >> 8) & 0xFF; 228 229 /* Update all the compensation registers in one shot */ 230 ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB, 231 comp_data, NUM_COMP_REGS); 232 if (ret < 0) { 233 dev_err(dev, "rtc_set_calibration error: %d\n", ret); 234 return ret; 235 } 236 237 /* Enable automatic compensation */ 238 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 239 TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP); 240 if (ret < 0) 241 dev_err(dev, "auto_comp enable failed with error: %d\n", ret); 242 243 return ret; 244 } 245 246 static int tps65910_rtc_get_calibration(struct device *dev, int *calibration) 247 { 248 unsigned char comp_data[NUM_COMP_REGS]; 249 struct tps65910 *tps = dev_get_drvdata(dev->parent); 250 unsigned int ctrl; 251 u16 value; 252 int ret; 253 254 ret = regmap_read(tps->regmap, TPS65910_RTC_CTRL, &ctrl); 255 if (ret < 0) 256 return ret; 257 258 /* If automatic compensation is not enabled report back zero */ 259 if (!(ctrl & TPS65910_RTC_CTRL_AUTO_COMP)) { 260 *calibration = 0; 261 return 0; 262 } 263 264 ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data, 265 NUM_COMP_REGS); 266 if (ret < 0) { 267 dev_err(dev, "rtc_get_calibration error: %d\n", ret); 268 return ret; 269 } 270 271 value = (u16)comp_data[0] | ((u16)comp_data[1] << 8); 272 273 *calibration = (s16)value; 274 275 return 0; 276 } 277 278 static int tps65910_read_offset(struct device *dev, long *offset) 279 { 280 int calibration; 281 s64 tmp; 282 int ret; 283 284 ret = tps65910_rtc_get_calibration(dev, &calibration); 285 if (ret < 0) 286 return ret; 287 288 /* Convert from RTC calibration register format to ppb format */ 289 tmp = calibration * (s64)PPB_MULT; 290 if (tmp < 0) 291 tmp -= TICKS_PER_HOUR / 2LL; 292 else 293 tmp += TICKS_PER_HOUR / 2LL; 294 tmp = div_s64(tmp, TICKS_PER_HOUR); 295 296 /* Offset value operates in negative way, so swap sign */ 297 *offset = (long)-tmp; 298 299 return 0; 300 } 301 302 static int tps65910_set_offset(struct device *dev, long offset) 303 { 304 int calibration; 305 s64 tmp; 306 int ret; 307 308 /* Make sure offset value is within supported range */ 309 if (offset < MIN_OFFSET || offset > MAX_OFFSET) 310 return -ERANGE; 311 312 /* Convert from ppb format to RTC calibration register format */ 313 tmp = offset * (s64)TICKS_PER_HOUR; 314 if (tmp < 0) 315 tmp -= PPB_MULT / 2LL; 316 else 317 tmp += PPB_MULT / 2LL; 318 tmp = div_s64(tmp, PPB_MULT); 319 320 /* Offset value operates in negative way, so swap sign */ 321 calibration = (int)-tmp; 322 323 ret = tps65910_rtc_set_calibration(dev, calibration); 324 325 return ret; 326 } 327 328 static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc) 329 { 330 struct device *dev = rtc; 331 unsigned long events = 0; 332 struct tps65910 *tps = dev_get_drvdata(dev->parent); 333 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); 334 int ret; 335 u32 rtc_reg; 336 337 ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg); 338 if (ret) 339 return IRQ_NONE; 340 341 if (rtc_reg & TPS65910_RTC_STATUS_ALARM) 342 events = RTC_IRQF | RTC_AF; 343 344 ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg); 345 if (ret) 346 return IRQ_NONE; 347 348 /* Notify RTC core on event */ 349 rtc_update_irq(tps_rtc->rtc, 1, events); 350 351 return IRQ_HANDLED; 352 } 353 354 static const struct rtc_class_ops tps65910_rtc_ops = { 355 .read_time = tps65910_rtc_read_time, 356 .set_time = tps65910_rtc_set_time, 357 .read_alarm = tps65910_rtc_read_alarm, 358 .set_alarm = tps65910_rtc_set_alarm, 359 .alarm_irq_enable = tps65910_rtc_alarm_irq_enable, 360 .read_offset = tps65910_read_offset, 361 .set_offset = tps65910_set_offset, 362 }; 363 364 static int tps65910_rtc_probe(struct platform_device *pdev) 365 { 366 struct tps65910 *tps65910 = NULL; 367 struct tps65910_rtc *tps_rtc = NULL; 368 int ret; 369 int irq; 370 u32 rtc_reg; 371 372 tps65910 = dev_get_drvdata(pdev->dev.parent); 373 374 tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc), 375 GFP_KERNEL); 376 if (!tps_rtc) 377 return -ENOMEM; 378 379 tps_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 380 if (IS_ERR(tps_rtc->rtc)) 381 return PTR_ERR(tps_rtc->rtc); 382 383 /* Clear pending interrupts */ 384 ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg); 385 if (ret < 0) 386 return ret; 387 388 ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg); 389 if (ret < 0) 390 return ret; 391 392 dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n"); 393 394 /* Enable RTC digital power domain */ 395 ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL, 396 DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT); 397 if (ret < 0) 398 return ret; 399 400 rtc_reg = TPS65910_RTC_CTRL_STOP_RTC; 401 ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg); 402 if (ret < 0) 403 return ret; 404 405 platform_set_drvdata(pdev, tps_rtc); 406 407 irq = platform_get_irq(pdev, 0); 408 if (irq <= 0) { 409 dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n", 410 irq); 411 return -ENXIO; 412 } 413 414 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, 415 tps65910_rtc_interrupt, IRQF_TRIGGER_LOW, 416 dev_name(&pdev->dev), &pdev->dev); 417 if (ret < 0) { 418 dev_err(&pdev->dev, "IRQ is not free.\n"); 419 return ret; 420 } 421 tps_rtc->irq = irq; 422 device_set_wakeup_capable(&pdev->dev, 1); 423 424 tps_rtc->rtc->ops = &tps65910_rtc_ops; 425 tps_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; 426 tps_rtc->rtc->range_max = RTC_TIMESTAMP_END_2099; 427 428 return rtc_register_device(tps_rtc->rtc); 429 } 430 431 #ifdef CONFIG_PM_SLEEP 432 static int tps65910_rtc_suspend(struct device *dev) 433 { 434 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); 435 436 if (device_may_wakeup(dev)) 437 enable_irq_wake(tps_rtc->irq); 438 return 0; 439 } 440 441 static int tps65910_rtc_resume(struct device *dev) 442 { 443 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); 444 445 if (device_may_wakeup(dev)) 446 disable_irq_wake(tps_rtc->irq); 447 return 0; 448 } 449 #endif 450 451 static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend, 452 tps65910_rtc_resume); 453 454 static struct platform_driver tps65910_rtc_driver = { 455 .probe = tps65910_rtc_probe, 456 .driver = { 457 .name = "tps65910-rtc", 458 .pm = &tps65910_rtc_pm_ops, 459 }, 460 }; 461 462 module_platform_driver(tps65910_rtc_driver); 463 MODULE_ALIAS("platform:rtc-tps65910"); 464 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>"); 465 MODULE_LICENSE("GPL"); 466