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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for Epson RX8111 RTC.4 *5 * Copyright (C) 2023 Axis Communications AB6 */7 8#include <linux/bcd.h>9#include <linux/bitfield.h>10#include <linux/i2c.h>11#include <linux/module.h>12#include <linux/regmap.h>13 14#include <linux/rtc.h>15 16#define RX8111_REG_SEC 0x10 /* Second counter. */17#define RX8111_REG_MIN 0x11 /* Minute counter */18#define RX8111_REG_HOUR 0x12 /* Hour counter. */19#define RX8111_REG_WEEK 0x13 /* Week day counter. */20#define RX8111_REG_DAY 0x14 /* Month day counter. */21#define RX8111_REG_MONTH 0x15 /* Month counter. */22#define RX8111_REG_YEAR 0x16 /* Year counter. */23 24#define RX8111_REG_ALARM_MIN 0x17 /* Alarm minute. */25#define RX8111_REG_ALARM_HOUR 0x18 /* Alarm hour. */26#define RX8111_REG_ALARM_WEEK_DAY 0x19 /* Alarm week or month day. */27 28#define RX8111_REG_TIMER_COUNTER0 0x1a /* Timer counter LSB. */29#define RX8111_REG_TIMER_COUNTER1 0x1b /* Timer counter. */30#define RX8111_REG_TIMER_COUNTER2 0x1c /* Timer counter MSB. */31 32#define RX8111_REG_EXT 0x1d /* Extension register. */33#define RX8111_REG_FLAG 0x1e /* Flag register. */34#define RX8111_REG_CTRL 0x1f /* Control register. */35 36#define RX8111_REG_TS_1_1000_SEC 0x20 /* Timestamp 256 or 512 Hz . */37#define RX8111_REG_TS_1_100_SEC 0x21 /* Timestamp 1 - 128 Hz. */38#define RX8111_REG_TS_SEC 0x22 /* Timestamp second. */39#define RX8111_REG_TS_MIN 0x23 /* Timestamp minute. */40#define RX8111_REG_TS_HOUR 0x24 /* Timestamp hour. */41#define RX8111_REG_TS_WEEK 0x25 /* Timestamp week day. */42#define RX8111_REG_TS_DAY 0x26 /* Timestamp month day. */43#define RX8111_REG_TS_MONTH 0x27 /* Timestamp month. */44#define RX8111_REG_TS_YEAR 0x28 /* Timestamp year. */45#define RX8111_REG_TS_STATUS 0x29 /* Timestamp status. */46 47#define RX8111_REG_EVIN_SETTING 0x2b /* Timestamp trigger setting. */48#define RX8111_REG_ALARM_SEC 0x2c /* Alarm second. */49#define RX8111_REG_TIMER_CTRL 0x2d /* Timer control. */50#define RX8111_REG_TS_CTRL0 0x2e /* Timestamp control 0. */51#define RX8111_REG_CMD_TRIGGER 0x2f /* Timestamp trigger. */52#define RX8111_REG_PWR_SWITCH_CTRL 0x32 /* Power switch control. */53#define RX8111_REG_STATUS_MON 0x33 /* Status monitor. */54#define RX8111_REG_TS_CTRL1 0x34 /* Timestamp control 1. */55#define RX8111_REG_TS_CTRL2 0x35 /* Timestamp control 2. */56#define RX8111_REG_TS_CTRL3 0x36 /* Timestamp control 3. */57 58#define RX8111_FLAG_XST_BIT BIT(0)59#define RX8111_FLAG_VLF_BIT BIT(1)60 61#define RX8111_TIME_BUF_SZ (RX8111_REG_YEAR - RX8111_REG_SEC + 1)62 63enum rx8111_regfield {64 /* RX8111_REG_EXT. */65 RX8111_REGF_TSEL0,66 RX8111_REGF_TSEL1,67 RX8111_REGF_ETS,68 RX8111_REGF_WADA,69 RX8111_REGF_TE,70 RX8111_REGF_USEL,71 RX8111_REGF_FSEL0,72 RX8111_REGF_FSEL1,73 74 /* RX8111_REG_FLAG. */75 RX8111_REGF_XST,76 RX8111_REGF_VLF,77 RX8111_REGF_EVF,78 RX8111_REGF_AF,79 RX8111_REGF_TF,80 RX8111_REGF_UF,81 RX8111_REGF_POR,82 83 /* RX8111_REG_CTRL. */84 RX8111_REGF_STOP,85 RX8111_REGF_EIE,86 RX8111_REGF_AIE,87 RX8111_REGF_TIE,88 RX8111_REGF_UIE,89 90 /* RX8111_REG_PWR_SWITCH_CTRL. */91 RX8111_REGF_SMPT0,92 RX8111_REGF_SMPT1,93 RX8111_REGF_SWSEL0,94 RX8111_REGF_SWSEL1,95 RX8111_REGF_INIEN,96 RX8111_REGF_CHGEN,97 98 /* RX8111_REG_STATUS_MON. */99 RX8111_REGF_VLOW,100 101 /* Sentinel value. */102 RX8111_REGF_MAX103};104 105static const struct reg_field rx8111_regfields[] = {106 [RX8111_REGF_TSEL0] = REG_FIELD(RX8111_REG_EXT, 0, 0),107 [RX8111_REGF_TSEL1] = REG_FIELD(RX8111_REG_EXT, 1, 1),108 [RX8111_REGF_ETS] = REG_FIELD(RX8111_REG_EXT, 2, 2),109 [RX8111_REGF_WADA] = REG_FIELD(RX8111_REG_EXT, 3, 3),110 [RX8111_REGF_TE] = REG_FIELD(RX8111_REG_EXT, 4, 4),111 [RX8111_REGF_USEL] = REG_FIELD(RX8111_REG_EXT, 5, 5),112 [RX8111_REGF_FSEL0] = REG_FIELD(RX8111_REG_EXT, 6, 6),113 [RX8111_REGF_FSEL1] = REG_FIELD(RX8111_REG_EXT, 7, 7),114 115 [RX8111_REGF_XST] = REG_FIELD(RX8111_REG_FLAG, 0, 0),116 [RX8111_REGF_VLF] = REG_FIELD(RX8111_REG_FLAG, 1, 1),117 [RX8111_REGF_EVF] = REG_FIELD(RX8111_REG_FLAG, 2, 2),118 [RX8111_REGF_AF] = REG_FIELD(RX8111_REG_FLAG, 3, 3),119 [RX8111_REGF_TF] = REG_FIELD(RX8111_REG_FLAG, 4, 4),120 [RX8111_REGF_UF] = REG_FIELD(RX8111_REG_FLAG, 5, 5),121 [RX8111_REGF_POR] = REG_FIELD(RX8111_REG_FLAG, 7, 7),122 123 [RX8111_REGF_STOP] = REG_FIELD(RX8111_REG_CTRL, 0, 0),124 [RX8111_REGF_EIE] = REG_FIELD(RX8111_REG_CTRL, 2, 2),125 [RX8111_REGF_AIE] = REG_FIELD(RX8111_REG_CTRL, 3, 3),126 [RX8111_REGF_TIE] = REG_FIELD(RX8111_REG_CTRL, 4, 4),127 [RX8111_REGF_UIE] = REG_FIELD(RX8111_REG_CTRL, 5, 5),128 129 [RX8111_REGF_SMPT0] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 0, 0),130 [RX8111_REGF_SMPT1] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 1, 1),131 [RX8111_REGF_SWSEL0] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 2, 2),132 [RX8111_REGF_SWSEL1] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 3, 3),133 [RX8111_REGF_INIEN] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 6, 6),134 [RX8111_REGF_CHGEN] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 7, 7),135 136 [RX8111_REGF_VLOW] = REG_FIELD(RX8111_REG_STATUS_MON, 1, 1),137};138 139static const struct regmap_config rx8111_regmap_config = {140 .reg_bits = 8,141 .val_bits = 8,142 .max_register = RX8111_REG_TS_CTRL3,143};144 145struct rx8111_data {146 struct regmap *regmap;147 struct regmap_field *regfields[RX8111_REGF_MAX];148 struct device *dev;149 struct rtc_device *rtc;150};151 152static int rx8111_read_vl_flag(struct rx8111_data *data, unsigned int *vlval)153{154 int ret;155 156 ret = regmap_field_read(data->regfields[RX8111_REGF_VLF], vlval);157 if (ret)158 dev_dbg(data->dev, "Could not read VL flag (%d)", ret);159 160 return ret;161}162 163static int rx8111_read_time(struct device *dev, struct rtc_time *tm)164{165 struct rx8111_data *data = dev_get_drvdata(dev);166 u8 buf[RX8111_TIME_BUF_SZ];167 unsigned int regval;168 int ret;169 170 /* Check status. */171 ret = regmap_read(data->regmap, RX8111_REG_FLAG, ®val);172 if (ret) {173 dev_dbg(data->dev, "Could not read flag register (%d)\n", ret);174 return ret;175 }176 177 if (FIELD_GET(RX8111_FLAG_XST_BIT, regval)) {178 dev_dbg(data->dev,179 "Crystal oscillation stopped, time is not reliable\n");180 return -EINVAL;181 }182 183 if (FIELD_GET(RX8111_FLAG_VLF_BIT, regval)) {184 dev_dbg(data->dev,185 "Low voltage detected, time is not reliable\n");186 return -EINVAL;187 }188 189 ret = regmap_field_read(data->regfields[RX8111_REGF_STOP], ®val);190 if (ret) {191 dev_dbg(data->dev, "Could not read clock status (%d)\n", ret);192 return ret;193 }194 195 if (regval) {196 dev_dbg(data->dev, "Clock stopped, time is not reliable\n");197 return -EINVAL;198 }199 200 /* Read time. */201 ret = regmap_bulk_read(data->regmap, RX8111_REG_SEC, buf,202 ARRAY_SIZE(buf));203 if (ret) {204 dev_dbg(data->dev, "Could not bulk read time (%d)\n", ret);205 return ret;206 }207 208 tm->tm_sec = bcd2bin(buf[0]);209 tm->tm_min = bcd2bin(buf[1]);210 tm->tm_hour = bcd2bin(buf[2]);211 tm->tm_wday = ffs(buf[3]) - 1;212 tm->tm_mday = bcd2bin(buf[4]);213 tm->tm_mon = bcd2bin(buf[5]) - 1;214 tm->tm_year = bcd2bin(buf[6]) + 100;215 216 return 0;217}218 219static int rx8111_set_time(struct device *dev, struct rtc_time *tm)220{221 struct rx8111_data *data = dev_get_drvdata(dev);222 u8 buf[RX8111_TIME_BUF_SZ];223 int ret;224 225 buf[0] = bin2bcd(tm->tm_sec);226 buf[1] = bin2bcd(tm->tm_min);227 buf[2] = bin2bcd(tm->tm_hour);228 buf[3] = BIT(tm->tm_wday);229 buf[4] = bin2bcd(tm->tm_mday);230 buf[5] = bin2bcd(tm->tm_mon + 1);231 buf[6] = bin2bcd(tm->tm_year - 100);232 233 ret = regmap_clear_bits(data->regmap, RX8111_REG_FLAG,234 RX8111_FLAG_XST_BIT | RX8111_FLAG_VLF_BIT);235 if (ret)236 return ret;237 238 /* Stop the clock. */239 ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 1);240 if (ret) {241 dev_dbg(data->dev, "Could not stop the clock (%d)\n", ret);242 return ret;243 }244 245 /* Set the time. */246 ret = regmap_bulk_write(data->regmap, RX8111_REG_SEC, buf,247 ARRAY_SIZE(buf));248 if (ret) {249 dev_dbg(data->dev, "Could not bulk write time (%d)\n", ret);250 251 /*252 * We don't bother with trying to start the clock again. We253 * check for this in rx8111_read_time() (and thus force user to254 * call rx8111_set_time() to try again).255 */256 return ret;257 }258 259 /* Start the clock. */260 ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 0);261 if (ret) {262 dev_dbg(data->dev, "Could not start the clock (%d)\n", ret);263 return ret;264 }265 266 return 0;267}268 269static int rx8111_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)270{271 struct rx8111_data *data = dev_get_drvdata(dev);272 unsigned int regval;273 unsigned int vlval;274 int ret;275 276 switch (cmd) {277 case RTC_VL_READ:278 ret = rx8111_read_vl_flag(data, ®val);279 if (ret)280 return ret;281 282 vlval = regval ? RTC_VL_DATA_INVALID : 0;283 284 ret = regmap_field_read(data->regfields[RX8111_REGF_VLOW],285 ®val);286 if (ret)287 return ret;288 289 vlval |= regval ? RTC_VL_BACKUP_LOW : 0;290 291 return put_user(vlval, (typeof(vlval) __user *)arg);292 default:293 return -ENOIOCTLCMD;294 }295}296 297static const struct rtc_class_ops rx8111_rtc_ops = {298 .read_time = rx8111_read_time,299 .set_time = rx8111_set_time,300 .ioctl = rx8111_ioctl,301};302 303static int rx8111_probe(struct i2c_client *client)304{305 struct rx8111_data *data;306 struct rtc_device *rtc;307 size_t i;308 309 data = devm_kmalloc(&client->dev, sizeof(*data), GFP_KERNEL);310 if (!data) {311 dev_dbg(&client->dev, "Could not allocate device data\n");312 return -ENOMEM;313 }314 315 data->dev = &client->dev;316 dev_set_drvdata(data->dev, data);317 318 data->regmap = devm_regmap_init_i2c(client, &rx8111_regmap_config);319 if (IS_ERR(data->regmap)) {320 dev_dbg(data->dev, "Could not initialize regmap\n");321 return PTR_ERR(data->regmap);322 }323 324 for (i = 0; i < RX8111_REGF_MAX; ++i) {325 data->regfields[i] = devm_regmap_field_alloc(326 data->dev, data->regmap, rx8111_regfields[i]);327 if (IS_ERR(data->regfields[i])) {328 dev_dbg(data->dev,329 "Could not allocate register field %zu\n", i);330 return PTR_ERR(data->regfields[i]);331 }332 }333 334 rtc = devm_rtc_allocate_device(data->dev);335 if (IS_ERR(rtc)) {336 dev_dbg(data->dev, "Could not allocate rtc device\n");337 return PTR_ERR(rtc);338 }339 340 rtc->ops = &rx8111_rtc_ops;341 rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;342 rtc->range_max = RTC_TIMESTAMP_END_2099;343 344 clear_bit(RTC_FEATURE_ALARM, rtc->features);345 346 return devm_rtc_register_device(rtc);347}348 349static const struct of_device_id rx8111_of_match[] = {350 {351 .compatible = "epson,rx8111",352 },353 {}354};355MODULE_DEVICE_TABLE(of, rx8111_of_match);356 357static struct i2c_driver rx8111_driver = {358 .driver = {359 .name = "rtc-rx8111",360 .of_match_table = rx8111_of_match,361 },362 .probe = rx8111_probe,363};364module_i2c_driver(rx8111_driver);365 366MODULE_AUTHOR("Waqar Hameed <waqar.hameed@axis.com>");367MODULE_DESCRIPTION("Epson RX8111 RTC driver");368MODULE_LICENSE("GPL");369