461 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * RTC driver for Rockchip RK8084 *5 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd6 *7 * Author: Chris Zhong <zyw@rock-chips.com>8 * Author: Zhang Qing <zhangqing@rock-chips.com>9 */10 11#include <linux/module.h>12#include <linux/kernel.h>13#include <linux/rtc.h>14#include <linux/bcd.h>15#include <linux/mfd/rk808.h>16#include <linux/platform_device.h>17 18/* RTC_CTRL_REG bitfields */19#define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0)20 21/* RK808 has a shadowed register for saving a "frozen" RTC time.22 * When user setting "GET_TIME" to 1, the time will save in this shadowed23 * register. If set "READSEL" to 1, user read rtc time register, actually24 * get the time of that moment. If we need the real time, clr this bit.25 */26#define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6)27#define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7)28#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M BIT(3)29#define RTC_STATUS_MASK 0xFE30 31#define SECONDS_REG_MSK 0x7F32#define MINUTES_REG_MAK 0x7F33#define HOURS_REG_MSK 0x3F34#define DAYS_REG_MSK 0x3F35#define MONTHS_REG_MSK 0x1F36#define YEARS_REG_MSK 0xFF37#define WEEKS_REG_MSK 0x738 39/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */40 41#define NUM_TIME_REGS (RK808_WEEKS_REG - RK808_SECONDS_REG + 1)42#define NUM_ALARM_REGS (RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)43 44struct rk_rtc_compat_reg {45 unsigned int ctrl_reg;46 unsigned int status_reg;47 unsigned int alarm_seconds_reg;48 unsigned int int_reg;49 unsigned int seconds_reg;50};51 52struct rk808_rtc {53 struct regmap *regmap;54 struct rtc_device *rtc;55 struct rk_rtc_compat_reg *creg;56 int irq;57};58 59/*60 * The Rockchip calendar used by the RK808 counts November with 31 days. We use61 * these translation functions to convert its dates to/from the Gregorian62 * calendar used by the rest of the world. We arbitrarily define Jan 1st, 201663 * as the day when both calendars were in sync, and treat all other dates64 * relative to that.65 * NOTE: Other system software (e.g. firmware) that reads the same hardware must66 * implement this exact same conversion algorithm, with the same anchor date.67 */68static time64_t nov2dec_transitions(struct rtc_time *tm)69{70 return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);71}72 73static void rockchip_to_gregorian(struct rtc_time *tm)74{75 /* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */76 time64_t time = rtc_tm_to_time64(tm);77 rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);78}79 80static void gregorian_to_rockchip(struct rtc_time *tm)81{82 time64_t extra_days = nov2dec_transitions(tm);83 time64_t time = rtc_tm_to_time64(tm);84 rtc_time64_to_tm(time - extra_days * 86400, tm);85 86 /* Compensate if we went back over Nov 31st (will work up to 2381) */87 if (nov2dec_transitions(tm) < extra_days) {88 if (tm->tm_mon + 1 == 11)89 tm->tm_mday++; /* This may result in 31! */90 else91 rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);92 }93}94 95/* Read current time and date in RTC */96static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)97{98 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);99 u8 rtc_data[NUM_TIME_REGS];100 int ret;101 102 /* Force an update of the shadowed registers right now */103 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->ctrl_reg,104 BIT_RTC_CTRL_REG_RTC_GET_TIME,105 BIT_RTC_CTRL_REG_RTC_GET_TIME);106 if (ret) {107 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);108 return ret;109 }110 111 /*112 * After we set the GET_TIME bit, the rtc time can't be read113 * immediately. So we should wait up to 31.25 us, about one cycle of114 * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer115 * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.116 */117 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->ctrl_reg,118 BIT_RTC_CTRL_REG_RTC_GET_TIME,119 0);120 if (ret) {121 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);122 return ret;123 }124 125 ret = regmap_bulk_read(rk808_rtc->regmap, rk808_rtc->creg->seconds_reg,126 rtc_data, NUM_TIME_REGS);127 if (ret) {128 dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);129 return ret;130 }131 132 tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);133 tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);134 tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);135 tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);136 tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;137 tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;138 tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);139 rockchip_to_gregorian(tm);140 dev_dbg(dev, "RTC date/time %ptRd(%d) %ptRt\n", tm, tm->tm_wday, tm);141 142 return ret;143}144 145/* Set current time and date in RTC */146static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)147{148 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);149 u8 rtc_data[NUM_TIME_REGS];150 int ret;151 152 dev_dbg(dev, "set RTC date/time %ptRd(%d) %ptRt\n", tm, tm->tm_wday, tm);153 gregorian_to_rockchip(tm);154 rtc_data[0] = bin2bcd(tm->tm_sec);155 rtc_data[1] = bin2bcd(tm->tm_min);156 rtc_data[2] = bin2bcd(tm->tm_hour);157 rtc_data[3] = bin2bcd(tm->tm_mday);158 rtc_data[4] = bin2bcd(tm->tm_mon + 1);159 rtc_data[5] = bin2bcd(tm->tm_year - 100);160 rtc_data[6] = bin2bcd(tm->tm_wday);161 162 /* Stop RTC while updating the RTC registers */163 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->ctrl_reg,164 BIT_RTC_CTRL_REG_STOP_RTC_M,165 BIT_RTC_CTRL_REG_STOP_RTC_M);166 if (ret) {167 dev_err(dev, "Failed to update RTC control: %d\n", ret);168 return ret;169 }170 171 ret = regmap_bulk_write(rk808_rtc->regmap, rk808_rtc->creg->seconds_reg,172 rtc_data, NUM_TIME_REGS);173 if (ret) {174 dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);175 return ret;176 }177 /* Start RTC again */178 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->ctrl_reg,179 BIT_RTC_CTRL_REG_STOP_RTC_M, 0);180 if (ret) {181 dev_err(dev, "Failed to update RTC control: %d\n", ret);182 return ret;183 }184 return 0;185}186 187/* Read alarm time and date in RTC */188static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)189{190 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);191 u8 alrm_data[NUM_ALARM_REGS];192 uint32_t int_reg;193 int ret;194 195 ret = regmap_bulk_read(rk808_rtc->regmap,196 rk808_rtc->creg->alarm_seconds_reg,197 alrm_data, NUM_ALARM_REGS);198 if (ret) {199 dev_err(dev, "Failed to read RTC alarm date REG: %d\n", ret);200 return ret;201 }202 203 alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);204 alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);205 alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);206 alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);207 alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;208 alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;209 rockchip_to_gregorian(&alrm->time);210 211 ret = regmap_read(rk808_rtc->regmap, rk808_rtc->creg->int_reg, &int_reg);212 if (ret) {213 dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);214 return ret;215 }216 217 dev_dbg(dev, "alrm read RTC date/time %ptRd(%d) %ptRt\n",218 &alrm->time, alrm->time.tm_wday, &alrm->time);219 220 alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;221 222 return 0;223}224 225static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)226{227 int ret;228 229 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->int_reg,230 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);231 232 return ret;233}234 235static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)236{237 int ret;238 239 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->int_reg,240 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,241 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);242 243 return ret;244}245 246static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)247{248 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);249 u8 alrm_data[NUM_ALARM_REGS];250 int ret;251 252 ret = rk808_rtc_stop_alarm(rk808_rtc);253 if (ret) {254 dev_err(dev, "Failed to stop alarm: %d\n", ret);255 return ret;256 }257 dev_dbg(dev, "alrm set RTC date/time %ptRd(%d) %ptRt\n",258 &alrm->time, alrm->time.tm_wday, &alrm->time);259 260 gregorian_to_rockchip(&alrm->time);261 alrm_data[0] = bin2bcd(alrm->time.tm_sec);262 alrm_data[1] = bin2bcd(alrm->time.tm_min);263 alrm_data[2] = bin2bcd(alrm->time.tm_hour);264 alrm_data[3] = bin2bcd(alrm->time.tm_mday);265 alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);266 alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);267 268 ret = regmap_bulk_write(rk808_rtc->regmap,269 rk808_rtc->creg->alarm_seconds_reg,270 alrm_data, NUM_ALARM_REGS);271 if (ret) {272 dev_err(dev, "Failed to bulk write: %d\n", ret);273 return ret;274 }275 if (alrm->enabled) {276 ret = rk808_rtc_start_alarm(rk808_rtc);277 if (ret) {278 dev_err(dev, "Failed to start alarm: %d\n", ret);279 return ret;280 }281 }282 return 0;283}284 285static int rk808_rtc_alarm_irq_enable(struct device *dev,286 unsigned int enabled)287{288 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);289 290 if (enabled)291 return rk808_rtc_start_alarm(rk808_rtc);292 293 return rk808_rtc_stop_alarm(rk808_rtc);294}295 296/*297 * We will just handle setting the frequency and make use the framework for298 * reading the periodic interupts.299 *300 * @freq: Current periodic IRQ freq:301 * bit 0: every second302 * bit 1: every minute303 * bit 2: every hour304 * bit 3: every day305 */306static irqreturn_t rk808_alarm_irq(int irq, void *data)307{308 struct rk808_rtc *rk808_rtc = data;309 int ret;310 311 ret = regmap_write(rk808_rtc->regmap, rk808_rtc->creg->status_reg,312 RTC_STATUS_MASK);313 if (ret) {314 dev_err(&rk808_rtc->rtc->dev,315 "%s:Failed to update RTC status: %d\n", __func__, ret);316 return ret;317 }318 319 rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);320 dev_dbg(&rk808_rtc->rtc->dev,321 "%s:irq=%d\n", __func__, irq);322 return IRQ_HANDLED;323}324 325static const struct rtc_class_ops rk808_rtc_ops = {326 .read_time = rk808_rtc_readtime,327 .set_time = rk808_rtc_set_time,328 .read_alarm = rk808_rtc_readalarm,329 .set_alarm = rk808_rtc_setalarm,330 .alarm_irq_enable = rk808_rtc_alarm_irq_enable,331};332 333#ifdef CONFIG_PM_SLEEP334/* Turn off the alarm if it should not be a wake source. */335static int rk808_rtc_suspend(struct device *dev)336{337 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);338 339 if (device_may_wakeup(dev))340 enable_irq_wake(rk808_rtc->irq);341 342 return 0;343}344 345/* Enable the alarm if it should be enabled (in case it was disabled to346 * prevent use as a wake source).347 */348static int rk808_rtc_resume(struct device *dev)349{350 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);351 352 if (device_may_wakeup(dev))353 disable_irq_wake(rk808_rtc->irq);354 355 return 0;356}357#endif358 359static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,360 rk808_rtc_suspend, rk808_rtc_resume);361 362static struct rk_rtc_compat_reg rk808_creg = {363 .ctrl_reg = RK808_RTC_CTRL_REG,364 .status_reg = RK808_RTC_STATUS_REG,365 .alarm_seconds_reg = RK808_ALARM_SECONDS_REG,366 .int_reg = RK808_RTC_INT_REG,367 .seconds_reg = RK808_SECONDS_REG,368};369 370static struct rk_rtc_compat_reg rk817_creg = {371 .ctrl_reg = RK817_RTC_CTRL_REG,372 .status_reg = RK817_RTC_STATUS_REG,373 .alarm_seconds_reg = RK817_ALARM_SECONDS_REG,374 .int_reg = RK817_RTC_INT_REG,375 .seconds_reg = RK817_SECONDS_REG,376};377 378static int rk808_rtc_probe(struct platform_device *pdev)379{380 struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);381 struct rk808_rtc *rk808_rtc;382 int ret;383 384 rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);385 if (rk808_rtc == NULL)386 return -ENOMEM;387 388 switch (rk808->variant) {389 case RK809_ID:390 case RK817_ID:391 rk808_rtc->creg = &rk817_creg;392 break;393 default:394 rk808_rtc->creg = &rk808_creg;395 break;396 }397 platform_set_drvdata(pdev, rk808_rtc);398 rk808_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);399 if (!rk808_rtc->regmap)400 return -ENODEV;401 402 /* start rtc running by default, and use shadowed timer. */403 ret = regmap_update_bits(rk808_rtc->regmap, rk808_rtc->creg->ctrl_reg,404 BIT_RTC_CTRL_REG_STOP_RTC_M |405 BIT_RTC_CTRL_REG_RTC_READSEL_M,406 BIT_RTC_CTRL_REG_RTC_READSEL_M);407 if (ret) {408 dev_err(&pdev->dev,409 "Failed to update RTC control: %d\n", ret);410 return ret;411 }412 413 ret = regmap_write(rk808_rtc->regmap, rk808_rtc->creg->status_reg,414 RTC_STATUS_MASK);415 if (ret) {416 dev_err(&pdev->dev,417 "Failed to write RTC status: %d\n", ret);418 return ret;419 }420 421 device_init_wakeup(&pdev->dev, 1);422 423 rk808_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);424 if (IS_ERR(rk808_rtc->rtc))425 return PTR_ERR(rk808_rtc->rtc);426 427 rk808_rtc->rtc->ops = &rk808_rtc_ops;428 429 rk808_rtc->irq = platform_get_irq(pdev, 0);430 if (rk808_rtc->irq < 0)431 return rk808_rtc->irq;432 433 /* request alarm irq of rk808 */434 ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,435 rk808_alarm_irq, 0,436 "RTC alarm", rk808_rtc);437 if (ret) {438 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",439 rk808_rtc->irq, ret);440 return ret;441 }442 443 return devm_rtc_register_device(rk808_rtc->rtc);444}445 446static struct platform_driver rk808_rtc_driver = {447 .probe = rk808_rtc_probe,448 .driver = {449 .name = "rk808-rtc",450 .pm = &rk808_rtc_pm_ops,451 },452};453 454module_platform_driver(rk808_rtc_driver);455 456MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");457MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");458MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");459MODULE_LICENSE("GPL");460MODULE_ALIAS("platform:rk808-rtc");461