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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 | // SPDX-License-Identifier: GPL-2.0 /* * RTC driver for tps6594 PMIC * * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/ */ #include <linux/bcd.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/limits.h> #include <linux/math64.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/mod_devicetable.h> #include <linux/property.h> #include <linux/rtc.h> #include <linux/types.h> #include <linux/units.h> #include <linux/mfd/tps6594.h> // Total number of RTC registers needed to set time #define NUM_TIME_REGS (TPS6594_REG_RTC_WEEKS - TPS6594_REG_RTC_SECONDS + 1) // Total number of RTC alarm registers #define NUM_TIME_ALARM_REGS (NUM_TIME_REGS - 1) /* * Min and max values supported by 'offset' interface (swapped sign). * After conversion, the values do not exceed the range [-32767, 33767] * which COMP_REG must conform to. */ #define MIN_OFFSET (-277774) #define MAX_OFFSET (277774) // Number of ticks per hour #define TICKS_PER_HOUR (32768 * 3600) // Multiplier for ppb conversions #define PPB_MULT NANO static int tps6594_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct tps6594 *tps = dev_get_drvdata(dev->parent); u8 val; val = enabled ? TPS6594_BIT_IT_ALARM : 0; return regmap_update_bits(tps->regmap, TPS6594_REG_RTC_INTERRUPTS, TPS6594_BIT_IT_ALARM, val); } /* Pulse GET_TIME field of RTC_CTRL_1 to store a timestamp in shadow registers. */ static int tps6594_rtc_shadow_timestamp(struct device *dev, struct tps6594 *tps) { int ret; /* * Set GET_TIME to 0. Next time we set GET_TIME to 1 we will be sure to store * an up-to-date timestamp. */ ret = regmap_clear_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_GET_TIME); if (ret < 0) return ret; /* * Copy content of RTC registers to shadow registers or latches to read * a coherent timestamp. */ return regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_GET_TIME); } static int tps6594_rtc_read_time(struct device *dev, struct rtc_time *tm) { unsigned char rtc_data[NUM_TIME_REGS]; struct tps6594 *tps = dev_get_drvdata(dev->parent); int ret; // Check if RTC is running. ret = regmap_test_bits(tps->regmap, TPS6594_REG_RTC_STATUS, TPS6594_BIT_RUN); if (ret < 0) return ret; if (ret == 0) return -EINVAL; ret = tps6594_rtc_shadow_timestamp(dev, tps); if (ret < 0) return ret; // Read shadowed RTC registers. ret = regmap_bulk_read(tps->regmap, TPS6594_REG_RTC_SECONDS, rtc_data, NUM_TIME_REGS); if (ret < 0) return ret; tm->tm_sec = bcd2bin(rtc_data[0]); tm->tm_min = bcd2bin(rtc_data[1]); tm->tm_hour = bcd2bin(rtc_data[2]); tm->tm_mday = bcd2bin(rtc_data[3]); tm->tm_mon = bcd2bin(rtc_data[4]) - 1; tm->tm_year = bcd2bin(rtc_data[5]) + 100; tm->tm_wday = bcd2bin(rtc_data[6]); return 0; } static int tps6594_rtc_set_time(struct device *dev, struct rtc_time *tm) { unsigned char rtc_data[NUM_TIME_REGS]; struct tps6594 *tps = dev_get_drvdata(dev->parent); int ret; rtc_data[0] = bin2bcd(tm->tm_sec); rtc_data[1] = bin2bcd(tm->tm_min); rtc_data[2] = bin2bcd(tm->tm_hour); rtc_data[3] = bin2bcd(tm->tm_mday); rtc_data[4] = bin2bcd(tm->tm_mon + 1); rtc_data[5] = bin2bcd(tm->tm_year - 100); rtc_data[6] = bin2bcd(tm->tm_wday); // Stop RTC while updating the RTC time registers. ret = regmap_clear_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_STOP_RTC); if (ret < 0) return ret; // Update all the time registers in one shot. ret = regmap_bulk_write(tps->regmap, TPS6594_REG_RTC_SECONDS, rtc_data, NUM_TIME_REGS); if (ret < 0) return ret; // Start back RTC. return regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_STOP_RTC); } static int tps6594_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { unsigned char alarm_data[NUM_TIME_ALARM_REGS]; u32 int_val; struct tps6594 *tps = dev_get_drvdata(dev->parent); int ret; ret = regmap_bulk_read(tps->regmap, TPS6594_REG_ALARM_SECONDS, alarm_data, NUM_TIME_ALARM_REGS); if (ret < 0) return ret; alm->time.tm_sec = bcd2bin(alarm_data[0]); alm->time.tm_min = bcd2bin(alarm_data[1]); alm->time.tm_hour = bcd2bin(alarm_data[2]); alm->time.tm_mday = bcd2bin(alarm_data[3]); alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; ret = regmap_read(tps->regmap, TPS6594_REG_RTC_INTERRUPTS, &int_val); if (ret < 0) return ret; alm->enabled = int_val & TPS6594_BIT_IT_ALARM; return 0; } static int tps6594_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { unsigned char alarm_data[NUM_TIME_ALARM_REGS]; struct tps6594 *tps = dev_get_drvdata(dev->parent); int ret; // Disable alarm irq before changing the alarm timestamp. ret = tps6594_rtc_alarm_irq_enable(dev, 0); if (ret) return ret; alarm_data[0] = bin2bcd(alm->time.tm_sec); alarm_data[1] = bin2bcd(alm->time.tm_min); alarm_data[2] = bin2bcd(alm->time.tm_hour); alarm_data[3] = bin2bcd(alm->time.tm_mday); alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); alarm_data[5] = bin2bcd(alm->time.tm_year - 100); // Update all the alarm registers in one shot. ret = regmap_bulk_write(tps->regmap, TPS6594_REG_ALARM_SECONDS, alarm_data, NUM_TIME_ALARM_REGS); if (ret < 0) return ret; if (alm->enabled) ret = tps6594_rtc_alarm_irq_enable(dev, 1); return ret; } static int tps6594_rtc_set_calibration(struct device *dev, int calibration) { struct tps6594 *tps = dev_get_drvdata(dev->parent); __le16 value; int ret; /* * TPS6594 uses two's complement 16 bit value for compensation of RTC * crystal inaccuracies. One time every hour when seconds counter * increments from 0 to 1 compensation value will be added to internal * RTC counter value. * * Valid range for compensation value: [-32767 .. 32767]. */ if (calibration < S16_MIN + 1 || calibration > S16_MAX) return -ERANGE; value = cpu_to_le16(calibration); // Update all the compensation registers in one shot. ret = regmap_bulk_write(tps->regmap, TPS6594_REG_RTC_COMP_LSB, &value, sizeof(value)); if (ret < 0) return ret; // Enable automatic compensation. return regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_AUTO_COMP); } static int tps6594_rtc_get_calibration(struct device *dev, int *calibration) { struct tps6594 *tps = dev_get_drvdata(dev->parent); unsigned int ctrl; __le16 value; int ret; ret = regmap_read(tps->regmap, TPS6594_REG_RTC_CTRL_1, &ctrl); if (ret < 0) return ret; // If automatic compensation is not enabled report back zero. if (!(ctrl & TPS6594_BIT_AUTO_COMP)) { *calibration = 0; return 0; } ret = regmap_bulk_read(tps->regmap, TPS6594_REG_RTC_COMP_LSB, &value, sizeof(value)); if (ret < 0) return ret; *calibration = le16_to_cpu(value); return 0; } static int tps6594_rtc_read_offset(struct device *dev, long *offset) { int calibration; s64 tmp; int ret; ret = tps6594_rtc_get_calibration(dev, &calibration); if (ret < 0) return ret; // Convert from RTC calibration register format to ppb format. tmp = calibration * PPB_MULT; if (tmp < 0) tmp -= TICKS_PER_HOUR / 2LL; else tmp += TICKS_PER_HOUR / 2LL; tmp = div_s64(tmp, TICKS_PER_HOUR); /* * SAFETY: * Computatiion is the reverse operation of the one done in * `tps6594_rtc_set_offset`. The safety remarks applie here too. */ /* * Offset value operates in negative way, so swap sign. * See 8.3.10.5, (32768 - COMP_REG). */ *offset = (long)-tmp; return 0; } static int tps6594_rtc_set_offset(struct device *dev, long offset) { int calibration; s64 tmp; // Make sure offset value is within supported range. if (offset < MIN_OFFSET || offset > MAX_OFFSET) return -ERANGE; // Convert from ppb format to RTC calibration register format. tmp = offset * TICKS_PER_HOUR; if (tmp < 0) tmp -= PPB_MULT / 2LL; else tmp += PPB_MULT / 2LL; tmp = div_s64(tmp, PPB_MULT); /* * SAFETY: * - tmp = offset * TICK_PER_HOUR : * `offset` can't be more than 277774, so `tmp` can't exceed 277774000000000 * which is lower than the maximum value in an `s64` (2^63-1). No overflow here. * * - tmp += TICK_PER_HOUR / 2LL : * tmp will have a maximum value of 277774117964800 which is still inferior to 2^63-1. */ // Offset value operates in negative way, so swap sign. calibration = (int)-tmp; return tps6594_rtc_set_calibration(dev, calibration); } static irqreturn_t tps6594_rtc_interrupt(int irq, void *rtc) { struct device *dev = rtc; struct tps6594 *tps = dev_get_drvdata(dev->parent); struct rtc_device *rtc_dev = dev_get_drvdata(dev); int ret; u32 rtc_reg; ret = regmap_read(tps->regmap, TPS6594_REG_RTC_STATUS, &rtc_reg); if (ret) return IRQ_NONE; rtc_update_irq(rtc_dev, 1, RTC_IRQF | RTC_AF); return IRQ_HANDLED; } static const struct rtc_class_ops tps6594_rtc_ops = { .read_time = tps6594_rtc_read_time, .set_time = tps6594_rtc_set_time, .read_alarm = tps6594_rtc_read_alarm, .set_alarm = tps6594_rtc_set_alarm, .alarm_irq_enable = tps6594_rtc_alarm_irq_enable, .read_offset = tps6594_rtc_read_offset, .set_offset = tps6594_rtc_set_offset, }; static int tps6594_rtc_probe(struct platform_device *pdev) { struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent); struct device *dev = &pdev->dev; struct rtc_device *rtc; int irq; int ret; rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; rtc = devm_rtc_allocate_device(dev); if (IS_ERR(rtc)) return PTR_ERR(rtc); // Enable crystal oscillator. ret = regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_2, TPS6594_BIT_XTAL_EN); if (ret < 0) return ret; ret = regmap_test_bits(tps->regmap, TPS6594_REG_RTC_STATUS, TPS6594_BIT_RUN); if (ret < 0) return ret; // RTC not running. if (ret == 0) { ret = regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_STOP_RTC); if (ret < 0) return ret; /* * On some boards, a 40 ms delay is needed before BIT_RUN is set. * 80 ms should provide sufficient margin. */ mdelay(80); /* * RTC should be running now. Check if this is the case. * If not it might be a missing oscillator. */ ret = regmap_test_bits(tps->regmap, TPS6594_REG_RTC_STATUS, TPS6594_BIT_RUN); if (ret < 0) return ret; if (ret == 0) return -ENODEV; // Stop RTC until first call to `tps6594_rtc_set_time`. ret = regmap_clear_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, TPS6594_BIT_STOP_RTC); if (ret < 0) return ret; } platform_set_drvdata(pdev, rtc); irq = platform_get_irq_byname(pdev, TPS6594_IRQ_NAME_ALARM); if (irq < 0) return dev_err_probe(dev, irq, "Failed to get irq\n"); ret = devm_request_threaded_irq(dev, irq, NULL, tps6594_rtc_interrupt, IRQF_ONESHOT, TPS6594_IRQ_NAME_ALARM, dev); if (ret < 0) return dev_err_probe(dev, ret, "Failed to request_threaded_irq\n"); ret = device_init_wakeup(dev, true); if (ret < 0) return dev_err_probe(dev, ret, "Failed to init rtc as wakeup source\n"); rtc->ops = &tps6594_rtc_ops; rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; rtc->range_max = RTC_TIMESTAMP_END_2099; return devm_rtc_register_device(rtc); } static const struct platform_device_id tps6594_rtc_id_table[] = { { "tps6594-rtc", }, {} }; MODULE_DEVICE_TABLE(platform, tps6594_rtc_id_table); static struct platform_driver tps6594_rtc_driver = { .probe = tps6594_rtc_probe, .driver = { .name = "tps6594-rtc", }, .id_table = tps6594_rtc_id_table, }; module_platform_driver(tps6594_rtc_driver); MODULE_AUTHOR("Esteban Blanc <eblanc@baylibre.com>"); MODULE_DESCRIPTION("TPS6594 RTC driver"); MODULE_LICENSE("GPL"); |