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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for the Epson RTC module RX-8010 SJ4 *5 * Copyright(C) Timesys Corporation 20156 * Copyright(C) General Electric Company 20157 */8 9#include <linux/bcd.h>10#include <linux/bitops.h>11#include <linux/i2c.h>12#include <linux/kernel.h>13#include <linux/module.h>14#include <linux/regmap.h>15#include <linux/rtc.h>16 17#define RX8010_SEC 0x1018#define RX8010_MIN 0x1119#define RX8010_HOUR 0x1220#define RX8010_WDAY 0x1321#define RX8010_MDAY 0x1422#define RX8010_MONTH 0x1523#define RX8010_YEAR 0x1624#define RX8010_RESV17 0x1725#define RX8010_ALMIN 0x1826#define RX8010_ALHOUR 0x1927#define RX8010_ALWDAY 0x1A28#define RX8010_TCOUNT0 0x1B29#define RX8010_TCOUNT1 0x1C30#define RX8010_EXT 0x1D31#define RX8010_FLAG 0x1E32#define RX8010_CTRL 0x1F33/* 0x20 to 0x2F are user registers */34#define RX8010_RESV30 0x3035#define RX8010_RESV31 0x3136#define RX8010_IRQ 0x3237 38#define RX8010_EXT_WADA BIT(3)39 40#define RX8010_FLAG_VLF BIT(1)41#define RX8010_FLAG_AF BIT(3)42#define RX8010_FLAG_TF BIT(4)43#define RX8010_FLAG_UF BIT(5)44 45#define RX8010_CTRL_AIE BIT(3)46#define RX8010_CTRL_UIE BIT(5)47#define RX8010_CTRL_STOP BIT(6)48#define RX8010_CTRL_TEST BIT(7)49 50#define RX8010_ALARM_AE BIT(7)51 52static const struct i2c_device_id rx8010_id[] = {53 { "rx8010" },54 { }55};56MODULE_DEVICE_TABLE(i2c, rx8010_id);57 58static const __maybe_unused struct of_device_id rx8010_of_match[] = {59 { .compatible = "epson,rx8010" },60 { }61};62MODULE_DEVICE_TABLE(of, rx8010_of_match);63 64struct rx8010_data {65 struct regmap *regs;66 struct rtc_device *rtc;67 u8 ctrlreg;68};69 70static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)71{72 struct i2c_client *client = dev_id;73 struct rx8010_data *rx8010 = i2c_get_clientdata(client);74 int flagreg, err;75 76 rtc_lock(rx8010->rtc);77 78 err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);79 if (err) {80 rtc_unlock(rx8010->rtc);81 return IRQ_NONE;82 }83 84 if (flagreg & RX8010_FLAG_VLF)85 dev_warn(&client->dev, "Frequency stop detected\n");86 87 if (flagreg & RX8010_FLAG_TF) {88 flagreg &= ~RX8010_FLAG_TF;89 rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);90 }91 92 if (flagreg & RX8010_FLAG_AF) {93 flagreg &= ~RX8010_FLAG_AF;94 rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);95 }96 97 if (flagreg & RX8010_FLAG_UF) {98 flagreg &= ~RX8010_FLAG_UF;99 rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);100 }101 102 err = regmap_write(rx8010->regs, RX8010_FLAG, flagreg);103 rtc_unlock(rx8010->rtc);104 return err ? IRQ_NONE : IRQ_HANDLED;105}106 107static int rx8010_get_time(struct device *dev, struct rtc_time *dt)108{109 struct rx8010_data *rx8010 = dev_get_drvdata(dev);110 u8 date[RX8010_YEAR - RX8010_SEC + 1];111 int flagreg, err;112 113 err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);114 if (err)115 return err;116 117 if (flagreg & RX8010_FLAG_VLF) {118 dev_warn(dev, "Frequency stop detected\n");119 return -EINVAL;120 }121 122 err = regmap_bulk_read(rx8010->regs, RX8010_SEC, date, sizeof(date));123 if (err)124 return err;125 126 dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);127 dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);128 dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);129 dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);130 dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;131 dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;132 dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);133 134 return 0;135}136 137static int rx8010_set_time(struct device *dev, struct rtc_time *dt)138{139 struct rx8010_data *rx8010 = dev_get_drvdata(dev);140 u8 date[RX8010_YEAR - RX8010_SEC + 1];141 int err;142 143 /* set STOP bit before changing clock/calendar */144 err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);145 if (err)146 return err;147 148 date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);149 date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);150 date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);151 date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);152 date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);153 date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);154 date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);155 156 err = regmap_bulk_write(rx8010->regs, RX8010_SEC, date, sizeof(date));157 if (err)158 return err;159 160 /* clear STOP bit after changing clock/calendar */161 err = regmap_clear_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);162 if (err)163 return err;164 165 err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF);166 if (err)167 return err;168 169 return 0;170}171 172static int rx8010_init(struct device *dev)173{174 struct rx8010_data *rx8010 = dev_get_drvdata(dev);175 u8 ctrl[2];176 int need_clear = 0, err;177 178 /* Initialize reserved registers as specified in datasheet */179 err = regmap_write(rx8010->regs, RX8010_RESV17, 0xD8);180 if (err)181 return err;182 183 err = regmap_write(rx8010->regs, RX8010_RESV30, 0x00);184 if (err)185 return err;186 187 err = regmap_write(rx8010->regs, RX8010_RESV31, 0x08);188 if (err)189 return err;190 191 err = regmap_write(rx8010->regs, RX8010_IRQ, 0x00);192 if (err)193 return err;194 195 err = regmap_bulk_read(rx8010->regs, RX8010_FLAG, ctrl, 2);196 if (err)197 return err;198 199 if (ctrl[0] & RX8010_FLAG_VLF)200 dev_warn(dev, "Frequency stop was detected\n");201 202 if (ctrl[0] & RX8010_FLAG_AF) {203 dev_warn(dev, "Alarm was detected\n");204 need_clear = 1;205 }206 207 if (ctrl[0] & RX8010_FLAG_TF)208 need_clear = 1;209 210 if (ctrl[0] & RX8010_FLAG_UF)211 need_clear = 1;212 213 if (need_clear) {214 ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);215 err = regmap_write(rx8010->regs, RX8010_FLAG, ctrl[0]);216 if (err)217 return err;218 }219 220 rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);221 222 return 0;223}224 225static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)226{227 struct rx8010_data *rx8010 = dev_get_drvdata(dev);228 u8 alarmvals[3];229 int flagreg, err;230 231 err = regmap_bulk_read(rx8010->regs, RX8010_ALMIN, alarmvals, 3);232 if (err)233 return err;234 235 err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);236 if (err)237 return err;238 239 t->time.tm_sec = 0;240 t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);241 t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);242 243 if (!(alarmvals[2] & RX8010_ALARM_AE))244 t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);245 246 t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);247 t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;248 249 return 0;250}251 252static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)253{254 struct rx8010_data *rx8010 = dev_get_drvdata(dev);255 u8 alarmvals[3];256 int err;257 258 if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {259 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);260 err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);261 if (err)262 return err;263 }264 265 err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);266 if (err)267 return err;268 269 alarmvals[0] = bin2bcd(t->time.tm_min);270 alarmvals[1] = bin2bcd(t->time.tm_hour);271 alarmvals[2] = bin2bcd(t->time.tm_mday);272 273 err = regmap_bulk_write(rx8010->regs, RX8010_ALMIN, alarmvals, 2);274 if (err)275 return err;276 277 err = regmap_clear_bits(rx8010->regs, RX8010_EXT, RX8010_EXT_WADA);278 if (err)279 return err;280 281 if (alarmvals[2] == 0)282 alarmvals[2] |= RX8010_ALARM_AE;283 284 err = regmap_write(rx8010->regs, RX8010_ALWDAY, alarmvals[2]);285 if (err)286 return err;287 288 if (t->enabled) {289 if (rx8010->rtc->uie_rtctimer.enabled)290 rx8010->ctrlreg |= RX8010_CTRL_UIE;291 if (rx8010->rtc->aie_timer.enabled)292 rx8010->ctrlreg |=293 (RX8010_CTRL_AIE | RX8010_CTRL_UIE);294 295 err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);296 if (err)297 return err;298 }299 300 return 0;301}302 303static int rx8010_alarm_irq_enable(struct device *dev,304 unsigned int enabled)305{306 struct rx8010_data *rx8010 = dev_get_drvdata(dev);307 int err;308 u8 ctrl;309 310 ctrl = rx8010->ctrlreg;311 312 if (enabled) {313 if (rx8010->rtc->uie_rtctimer.enabled)314 ctrl |= RX8010_CTRL_UIE;315 if (rx8010->rtc->aie_timer.enabled)316 ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);317 } else {318 if (!rx8010->rtc->uie_rtctimer.enabled)319 ctrl &= ~RX8010_CTRL_UIE;320 if (!rx8010->rtc->aie_timer.enabled)321 ctrl &= ~RX8010_CTRL_AIE;322 }323 324 err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);325 if (err)326 return err;327 328 if (ctrl != rx8010->ctrlreg) {329 rx8010->ctrlreg = ctrl;330 err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);331 if (err)332 return err;333 }334 335 return 0;336}337 338static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)339{340 struct rx8010_data *rx8010 = dev_get_drvdata(dev);341 int tmp, flagreg, err;342 343 switch (cmd) {344 case RTC_VL_READ:345 err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);346 if (err)347 return err;348 349 tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;350 return put_user(tmp, (unsigned int __user *)arg);351 352 default:353 return -ENOIOCTLCMD;354 }355}356 357static const struct rtc_class_ops rx8010_rtc_ops = {358 .read_time = rx8010_get_time,359 .set_time = rx8010_set_time,360 .ioctl = rx8010_ioctl,361 .read_alarm = rx8010_read_alarm,362 .set_alarm = rx8010_set_alarm,363 .alarm_irq_enable = rx8010_alarm_irq_enable,364};365 366static const struct regmap_config rx8010_regmap_config = {367 .name = "rx8010-rtc",368 .reg_bits = 8,369 .val_bits = 8,370};371 372static int rx8010_probe(struct i2c_client *client)373{374 struct device *dev = &client->dev;375 struct rx8010_data *rx8010;376 int err = 0;377 378 rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);379 if (!rx8010)380 return -ENOMEM;381 382 i2c_set_clientdata(client, rx8010);383 384 rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config);385 if (IS_ERR(rx8010->regs))386 return PTR_ERR(rx8010->regs);387 388 err = rx8010_init(dev);389 if (err)390 return err;391 392 rx8010->rtc = devm_rtc_allocate_device(dev);393 if (IS_ERR(rx8010->rtc))394 return PTR_ERR(rx8010->rtc);395 396 if (client->irq > 0) {397 unsigned long irqflags = IRQF_TRIGGER_LOW;398 399 if (dev_fwnode(&client->dev))400 irqflags = 0;401 402 err = devm_request_threaded_irq(dev, client->irq, NULL,403 rx8010_irq_1_handler,404 irqflags | IRQF_ONESHOT,405 "rx8010", client);406 if (err) {407 dev_err(dev, "unable to request IRQ\n");408 return err;409 }410 } else {411 clear_bit(RTC_FEATURE_ALARM, rx8010->rtc->features);412 }413 414 rx8010->rtc->ops = &rx8010_rtc_ops;415 rx8010->rtc->max_user_freq = 1;416 rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;417 rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099;418 419 return devm_rtc_register_device(rx8010->rtc);420}421 422static struct i2c_driver rx8010_driver = {423 .driver = {424 .name = "rtc-rx8010",425 .of_match_table = of_match_ptr(rx8010_of_match),426 },427 .probe = rx8010_probe,428 .id_table = rx8010_id,429};430 431module_i2c_driver(rx8010_driver);432 433MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");434MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");435MODULE_LICENSE("GPL v2");436