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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * An RTC driver for Allwinner A10/A204 *5 * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>6 */7 8#include <linux/delay.h>9#include <linux/err.h>10#include <linux/fs.h>11#include <linux/init.h>12#include <linux/interrupt.h>13#include <linux/io.h>14#include <linux/kernel.h>15#include <linux/module.h>16#include <linux/of.h>17#include <linux/platform_device.h>18#include <linux/rtc.h>19#include <linux/types.h>20 21#define SUNXI_LOSC_CTRL 0x000022#define SUNXI_LOSC_CTRL_RTC_HMS_ACC BIT(8)23#define SUNXI_LOSC_CTRL_RTC_YMD_ACC BIT(7)24 25#define SUNXI_RTC_YMD 0x000426 27#define SUNXI_RTC_HMS 0x000828 29#define SUNXI_ALRM_DHMS 0x000c30 31#define SUNXI_ALRM_EN 0x001432#define SUNXI_ALRM_EN_CNT_EN BIT(8)33 34#define SUNXI_ALRM_IRQ_EN 0x001835#define SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0)36 37#define SUNXI_ALRM_IRQ_STA 0x001c38#define SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0)39 40#define SUNXI_MASK_DH 0x0000001f41#define SUNXI_MASK_SM 0x0000003f42#define SUNXI_MASK_M 0x0000000f43#define SUNXI_MASK_LY 0x0000000144#define SUNXI_MASK_D 0x00000ffe45#define SUNXI_MASK_M 0x0000000f46 47#define SUNXI_GET(x, mask, shift) (((x) & ((mask) << (shift))) \48 >> (shift))49 50#define SUNXI_SET(x, mask, shift) (((x) & (mask)) << (shift))51 52/*53 * Get date values54 */55#define SUNXI_DATE_GET_DAY_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 0)56#define SUNXI_DATE_GET_MON_VALUE(x) SUNXI_GET(x, SUNXI_MASK_M, 8)57#define SUNXI_DATE_GET_YEAR_VALUE(x, mask) SUNXI_GET(x, mask, 16)58 59/*60 * Get time values61 */62#define SUNXI_TIME_GET_SEC_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 0)63#define SUNXI_TIME_GET_MIN_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 8)64#define SUNXI_TIME_GET_HOUR_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 16)65 66/*67 * Get alarm values68 */69#define SUNXI_ALRM_GET_SEC_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 0)70#define SUNXI_ALRM_GET_MIN_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 8)71#define SUNXI_ALRM_GET_HOUR_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 16)72 73/*74 * Set date values75 */76#define SUNXI_DATE_SET_DAY_VALUE(x) SUNXI_DATE_GET_DAY_VALUE(x)77#define SUNXI_DATE_SET_MON_VALUE(x) SUNXI_SET(x, SUNXI_MASK_M, 8)78#define SUNXI_DATE_SET_YEAR_VALUE(x, mask) SUNXI_SET(x, mask, 16)79#define SUNXI_LEAP_SET_VALUE(x, shift) SUNXI_SET(x, SUNXI_MASK_LY, shift)80 81/*82 * Set time values83 */84#define SUNXI_TIME_SET_SEC_VALUE(x) SUNXI_TIME_GET_SEC_VALUE(x)85#define SUNXI_TIME_SET_MIN_VALUE(x) SUNXI_SET(x, SUNXI_MASK_SM, 8)86#define SUNXI_TIME_SET_HOUR_VALUE(x) SUNXI_SET(x, SUNXI_MASK_DH, 16)87 88/*89 * Set alarm values90 */91#define SUNXI_ALRM_SET_SEC_VALUE(x) SUNXI_ALRM_GET_SEC_VALUE(x)92#define SUNXI_ALRM_SET_MIN_VALUE(x) SUNXI_SET(x, SUNXI_MASK_SM, 8)93#define SUNXI_ALRM_SET_HOUR_VALUE(x) SUNXI_SET(x, SUNXI_MASK_DH, 16)94#define SUNXI_ALRM_SET_DAY_VALUE(x) SUNXI_SET(x, SUNXI_MASK_D, 21)95 96/*97 * Time unit conversions98 */99#define SEC_IN_MIN 60100#define SEC_IN_HOUR (60 * SEC_IN_MIN)101#define SEC_IN_DAY (24 * SEC_IN_HOUR)102 103/*104 * The year parameter passed to the driver is usually an offset relative to105 * the year 1900. This macro is used to convert this offset to another one106 * relative to the minimum year allowed by the hardware.107 */108#define SUNXI_YEAR_OFF(x) ((x)->min - 1900)109 110/*111 * min and max year are arbitrary set considering the limited range of the112 * hardware register field113 */114struct sunxi_rtc_data_year {115 unsigned int min; /* min year allowed */116 unsigned int max; /* max year allowed */117 unsigned int mask; /* mask for the year field */118 unsigned char leap_shift; /* bit shift to get the leap year */119};120 121static const struct sunxi_rtc_data_year data_year_param[] = {122 [0] = {123 .min = 2010,124 .max = 2073,125 .mask = 0x3f,126 .leap_shift = 22,127 },128 [1] = {129 .min = 1970,130 .max = 2225,131 .mask = 0xff,132 .leap_shift = 24,133 },134};135 136struct sunxi_rtc_dev {137 struct rtc_device *rtc;138 struct device *dev;139 const struct sunxi_rtc_data_year *data_year;140 void __iomem *base;141 int irq;142};143 144static irqreturn_t sunxi_rtc_alarmirq(int irq, void *id)145{146 struct sunxi_rtc_dev *chip = (struct sunxi_rtc_dev *) id;147 u32 val;148 149 val = readl(chip->base + SUNXI_ALRM_IRQ_STA);150 151 if (val & SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND) {152 val |= SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND;153 writel(val, chip->base + SUNXI_ALRM_IRQ_STA);154 155 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);156 157 return IRQ_HANDLED;158 }159 160 return IRQ_NONE;161}162 163static void sunxi_rtc_setaie(unsigned int to, struct sunxi_rtc_dev *chip)164{165 u32 alrm_val = 0;166 u32 alrm_irq_val = 0;167 168 if (to) {169 alrm_val = readl(chip->base + SUNXI_ALRM_EN);170 alrm_val |= SUNXI_ALRM_EN_CNT_EN;171 172 alrm_irq_val = readl(chip->base + SUNXI_ALRM_IRQ_EN);173 alrm_irq_val |= SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN;174 } else {175 writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND,176 chip->base + SUNXI_ALRM_IRQ_STA);177 }178 179 writel(alrm_val, chip->base + SUNXI_ALRM_EN);180 writel(alrm_irq_val, chip->base + SUNXI_ALRM_IRQ_EN);181}182 183static int sunxi_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)184{185 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);186 struct rtc_time *alrm_tm = &wkalrm->time;187 u32 alrm;188 u32 alrm_en;189 u32 date;190 191 alrm = readl(chip->base + SUNXI_ALRM_DHMS);192 date = readl(chip->base + SUNXI_RTC_YMD);193 194 alrm_tm->tm_sec = SUNXI_ALRM_GET_SEC_VALUE(alrm);195 alrm_tm->tm_min = SUNXI_ALRM_GET_MIN_VALUE(alrm);196 alrm_tm->tm_hour = SUNXI_ALRM_GET_HOUR_VALUE(alrm);197 198 alrm_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date);199 alrm_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date);200 alrm_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date,201 chip->data_year->mask);202 203 alrm_tm->tm_mon -= 1;204 205 /*206 * switch from (data_year->min)-relative offset to207 * a (1900)-relative one208 */209 alrm_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year);210 211 alrm_en = readl(chip->base + SUNXI_ALRM_IRQ_EN);212 if (alrm_en & SUNXI_ALRM_EN_CNT_EN)213 wkalrm->enabled = 1;214 215 return 0;216}217 218static int sunxi_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)219{220 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);221 u32 date, time;222 223 /*224 * read again in case it changes225 */226 do {227 date = readl(chip->base + SUNXI_RTC_YMD);228 time = readl(chip->base + SUNXI_RTC_HMS);229 } while ((date != readl(chip->base + SUNXI_RTC_YMD)) ||230 (time != readl(chip->base + SUNXI_RTC_HMS)));231 232 rtc_tm->tm_sec = SUNXI_TIME_GET_SEC_VALUE(time);233 rtc_tm->tm_min = SUNXI_TIME_GET_MIN_VALUE(time);234 rtc_tm->tm_hour = SUNXI_TIME_GET_HOUR_VALUE(time);235 236 rtc_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date);237 rtc_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date);238 rtc_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date,239 chip->data_year->mask);240 241 rtc_tm->tm_mon -= 1;242 243 /*244 * switch from (data_year->min)-relative offset to245 * a (1900)-relative one246 */247 rtc_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year);248 249 return 0;250}251 252static int sunxi_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)253{254 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);255 struct rtc_time *alrm_tm = &wkalrm->time;256 struct rtc_time tm_now;257 u32 alrm;258 time64_t diff;259 unsigned long time_gap;260 unsigned long time_gap_day;261 unsigned long time_gap_hour;262 unsigned long time_gap_min;263 int ret;264 265 ret = sunxi_rtc_gettime(dev, &tm_now);266 if (ret < 0) {267 dev_err(dev, "Error in getting time\n");268 return -EINVAL;269 }270 271 diff = rtc_tm_sub(alrm_tm, &tm_now);272 if (diff <= 0) {273 dev_err(dev, "Date to set in the past\n");274 return -EINVAL;275 }276 277 if (diff > 255 * SEC_IN_DAY) {278 dev_err(dev, "Day must be in the range 0 - 255\n");279 return -EINVAL;280 }281 282 time_gap = diff;283 time_gap_day = time_gap / SEC_IN_DAY;284 time_gap -= time_gap_day * SEC_IN_DAY;285 time_gap_hour = time_gap / SEC_IN_HOUR;286 time_gap -= time_gap_hour * SEC_IN_HOUR;287 time_gap_min = time_gap / SEC_IN_MIN;288 time_gap -= time_gap_min * SEC_IN_MIN;289 290 sunxi_rtc_setaie(0, chip);291 writel(0, chip->base + SUNXI_ALRM_DHMS);292 usleep_range(100, 300);293 294 alrm = SUNXI_ALRM_SET_SEC_VALUE(time_gap) |295 SUNXI_ALRM_SET_MIN_VALUE(time_gap_min) |296 SUNXI_ALRM_SET_HOUR_VALUE(time_gap_hour) |297 SUNXI_ALRM_SET_DAY_VALUE(time_gap_day);298 writel(alrm, chip->base + SUNXI_ALRM_DHMS);299 300 writel(0, chip->base + SUNXI_ALRM_IRQ_EN);301 writel(SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN, chip->base + SUNXI_ALRM_IRQ_EN);302 303 sunxi_rtc_setaie(wkalrm->enabled, chip);304 305 return 0;306}307 308static int sunxi_rtc_wait(struct sunxi_rtc_dev *chip, int offset,309 unsigned int mask, unsigned int ms_timeout)310{311 const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);312 u32 reg;313 314 do {315 reg = readl(chip->base + offset);316 reg &= mask;317 318 if (reg == mask)319 return 0;320 321 } while (time_before(jiffies, timeout));322 323 return -ETIMEDOUT;324}325 326static int sunxi_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)327{328 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);329 u32 date = 0;330 u32 time = 0;331 unsigned int year;332 333 /*334 * the input rtc_tm->tm_year is the offset relative to 1900. We use335 * the SUNXI_YEAR_OFF macro to rebase it with respect to the min year336 * allowed by the hardware337 */338 339 year = rtc_tm->tm_year + 1900;340 if (year < chip->data_year->min || year > chip->data_year->max) {341 dev_err(dev, "rtc only supports year in range %u - %u\n",342 chip->data_year->min, chip->data_year->max);343 return -EINVAL;344 }345 346 rtc_tm->tm_year -= SUNXI_YEAR_OFF(chip->data_year);347 rtc_tm->tm_mon += 1;348 349 date = SUNXI_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |350 SUNXI_DATE_SET_MON_VALUE(rtc_tm->tm_mon) |351 SUNXI_DATE_SET_YEAR_VALUE(rtc_tm->tm_year,352 chip->data_year->mask);353 354 if (is_leap_year(year))355 date |= SUNXI_LEAP_SET_VALUE(1, chip->data_year->leap_shift);356 357 time = SUNXI_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) |358 SUNXI_TIME_SET_MIN_VALUE(rtc_tm->tm_min) |359 SUNXI_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);360 361 writel(0, chip->base + SUNXI_RTC_HMS);362 writel(0, chip->base + SUNXI_RTC_YMD);363 364 writel(time, chip->base + SUNXI_RTC_HMS);365 366 /*367 * After writing the RTC HH-MM-SS register, the368 * SUNXI_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not369 * be cleared until the real writing operation is finished370 */371 372 if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL,373 SUNXI_LOSC_CTRL_RTC_HMS_ACC, 50)) {374 dev_err(dev, "Failed to set rtc time.\n");375 return -1;376 }377 378 writel(date, chip->base + SUNXI_RTC_YMD);379 380 /*381 * After writing the RTC YY-MM-DD register, the382 * SUNXI_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not383 * be cleared until the real writing operation is finished384 */385 386 if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL,387 SUNXI_LOSC_CTRL_RTC_YMD_ACC, 50)) {388 dev_err(dev, "Failed to set rtc time.\n");389 return -1;390 }391 392 return 0;393}394 395static int sunxi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)396{397 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);398 399 if (!enabled)400 sunxi_rtc_setaie(enabled, chip);401 402 return 0;403}404 405static const struct rtc_class_ops sunxi_rtc_ops = {406 .read_time = sunxi_rtc_gettime,407 .set_time = sunxi_rtc_settime,408 .read_alarm = sunxi_rtc_getalarm,409 .set_alarm = sunxi_rtc_setalarm,410 .alarm_irq_enable = sunxi_rtc_alarm_irq_enable411};412 413static const struct of_device_id sunxi_rtc_dt_ids[] = {414 { .compatible = "allwinner,sun4i-a10-rtc", .data = &data_year_param[0] },415 { .compatible = "allwinner,sun7i-a20-rtc", .data = &data_year_param[1] },416 { /* sentinel */ },417};418MODULE_DEVICE_TABLE(of, sunxi_rtc_dt_ids);419 420static int sunxi_rtc_probe(struct platform_device *pdev)421{422 struct sunxi_rtc_dev *chip;423 int ret;424 425 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);426 if (!chip)427 return -ENOMEM;428 429 platform_set_drvdata(pdev, chip);430 chip->dev = &pdev->dev;431 432 chip->rtc = devm_rtc_allocate_device(&pdev->dev);433 if (IS_ERR(chip->rtc))434 return PTR_ERR(chip->rtc);435 436 chip->base = devm_platform_ioremap_resource(pdev, 0);437 if (IS_ERR(chip->base))438 return PTR_ERR(chip->base);439 440 chip->irq = platform_get_irq(pdev, 0);441 if (chip->irq < 0)442 return chip->irq;443 ret = devm_request_irq(&pdev->dev, chip->irq, sunxi_rtc_alarmirq,444 0, dev_name(&pdev->dev), chip);445 if (ret) {446 dev_err(&pdev->dev, "Could not request IRQ\n");447 return ret;448 }449 450 chip->data_year = of_device_get_match_data(&pdev->dev);451 if (!chip->data_year) {452 dev_err(&pdev->dev, "Unable to setup RTC data\n");453 return -ENODEV;454 }455 456 /* clear the alarm count value */457 writel(0, chip->base + SUNXI_ALRM_DHMS);458 459 /* disable alarm, not generate irq pending */460 writel(0, chip->base + SUNXI_ALRM_EN);461 462 /* disable alarm week/cnt irq, unset to cpu */463 writel(0, chip->base + SUNXI_ALRM_IRQ_EN);464 465 /* clear alarm week/cnt irq pending */466 writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +467 SUNXI_ALRM_IRQ_STA);468 469 chip->rtc->ops = &sunxi_rtc_ops;470 471 return devm_rtc_register_device(chip->rtc);472}473 474static struct platform_driver sunxi_rtc_driver = {475 .probe = sunxi_rtc_probe,476 .driver = {477 .name = "sunxi-rtc",478 .of_match_table = sunxi_rtc_dt_ids,479 },480};481 482module_platform_driver(sunxi_rtc_driver);483 484MODULE_DESCRIPTION("sunxi RTC driver");485MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");486MODULE_LICENSE("GPL");487