1 /* 2 * drivers/rtc/rtc-pcf85363.c 3 * 4 * Driver for NXP PCF85363 real-time clock. 5 * 6 * Copyright (C) 2017 Eric Nelson 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * Based loosely on rtc-8583 by Russell King, Wolfram Sang and Juergen Beisert 13 */ 14 #include <linux/module.h> 15 #include <linux/i2c.h> 16 #include <linux/slab.h> 17 #include <linux/rtc.h> 18 #include <linux/init.h> 19 #include <linux/err.h> 20 #include <linux/errno.h> 21 #include <linux/bcd.h> 22 #include <linux/of.h> 23 #include <linux/of_device.h> 24 #include <linux/regmap.h> 25 26 /* 27 * Date/Time registers 28 */ 29 #define DT_100THS 0x00 30 #define DT_SECS 0x01 31 #define DT_MINUTES 0x02 32 #define DT_HOURS 0x03 33 #define DT_DAYS 0x04 34 #define DT_WEEKDAYS 0x05 35 #define DT_MONTHS 0x06 36 #define DT_YEARS 0x07 37 38 /* 39 * Alarm registers 40 */ 41 #define DT_SECOND_ALM1 0x08 42 #define DT_MINUTE_ALM1 0x09 43 #define DT_HOUR_ALM1 0x0a 44 #define DT_DAY_ALM1 0x0b 45 #define DT_MONTH_ALM1 0x0c 46 #define DT_MINUTE_ALM2 0x0d 47 #define DT_HOUR_ALM2 0x0e 48 #define DT_WEEKDAY_ALM2 0x0f 49 #define DT_ALARM_EN 0x10 50 51 /* 52 * Time stamp registers 53 */ 54 #define DT_TIMESTAMP1 0x11 55 #define DT_TIMESTAMP2 0x17 56 #define DT_TIMESTAMP3 0x1d 57 #define DT_TS_MODE 0x23 58 59 /* 60 * control registers 61 */ 62 #define CTRL_OFFSET 0x24 63 #define CTRL_OSCILLATOR 0x25 64 #define CTRL_BATTERY 0x26 65 #define CTRL_PIN_IO 0x27 66 #define CTRL_FUNCTION 0x28 67 #define CTRL_INTA_EN 0x29 68 #define CTRL_INTB_EN 0x2a 69 #define CTRL_FLAGS 0x2b 70 #define CTRL_RAMBYTE 0x2c 71 #define CTRL_WDOG 0x2d 72 #define CTRL_STOP_EN 0x2e 73 #define CTRL_RESETS 0x2f 74 #define CTRL_RAM 0x40 75 76 #define ALRM_SEC_A1E BIT(0) 77 #define ALRM_MIN_A1E BIT(1) 78 #define ALRM_HR_A1E BIT(2) 79 #define ALRM_DAY_A1E BIT(3) 80 #define ALRM_MON_A1E BIT(4) 81 #define ALRM_MIN_A2E BIT(5) 82 #define ALRM_HR_A2E BIT(6) 83 #define ALRM_DAY_A2E BIT(7) 84 85 #define INT_WDIE BIT(0) 86 #define INT_BSIE BIT(1) 87 #define INT_TSRIE BIT(2) 88 #define INT_A2IE BIT(3) 89 #define INT_A1IE BIT(4) 90 #define INT_OIE BIT(5) 91 #define INT_PIE BIT(6) 92 #define INT_ILP BIT(7) 93 94 #define FLAGS_TSR1F BIT(0) 95 #define FLAGS_TSR2F BIT(1) 96 #define FLAGS_TSR3F BIT(2) 97 #define FLAGS_BSF BIT(3) 98 #define FLAGS_WDF BIT(4) 99 #define FLAGS_A1F BIT(5) 100 #define FLAGS_A2F BIT(6) 101 #define FLAGS_PIF BIT(7) 102 103 #define PIN_IO_INTAPM GENMASK(1, 0) 104 #define PIN_IO_INTA_CLK 0 105 #define PIN_IO_INTA_BAT 1 106 #define PIN_IO_INTA_OUT 2 107 #define PIN_IO_INTA_HIZ 3 108 109 #define STOP_EN_STOP BIT(0) 110 111 #define RESET_CPR 0xa4 112 113 #define NVRAM_SIZE 0x40 114 115 static struct i2c_driver pcf85363_driver; 116 117 struct pcf85363 { 118 struct device *dev; 119 struct rtc_device *rtc; 120 struct regmap *regmap; 121 }; 122 123 static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm) 124 { 125 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 126 unsigned char buf[DT_YEARS + 1]; 127 int ret, len = sizeof(buf); 128 129 /* read the RTC date and time registers all at once */ 130 ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len); 131 if (ret) { 132 dev_err(dev, "%s: error %d\n", __func__, ret); 133 return ret; 134 } 135 136 tm->tm_year = bcd2bin(buf[DT_YEARS]); 137 /* adjust for 1900 base of rtc_time */ 138 tm->tm_year += 100; 139 140 tm->tm_wday = buf[DT_WEEKDAYS] & 7; 141 buf[DT_SECS] &= 0x7F; 142 tm->tm_sec = bcd2bin(buf[DT_SECS]); 143 buf[DT_MINUTES] &= 0x7F; 144 tm->tm_min = bcd2bin(buf[DT_MINUTES]); 145 tm->tm_hour = bcd2bin(buf[DT_HOURS]); 146 tm->tm_mday = bcd2bin(buf[DT_DAYS]); 147 tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1; 148 149 return 0; 150 } 151 152 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm) 153 { 154 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 155 unsigned char tmp[11]; 156 unsigned char *buf = &tmp[2]; 157 int ret; 158 159 tmp[0] = STOP_EN_STOP; 160 tmp[1] = RESET_CPR; 161 162 buf[DT_100THS] = 0; 163 buf[DT_SECS] = bin2bcd(tm->tm_sec); 164 buf[DT_MINUTES] = bin2bcd(tm->tm_min); 165 buf[DT_HOURS] = bin2bcd(tm->tm_hour); 166 buf[DT_DAYS] = bin2bcd(tm->tm_mday); 167 buf[DT_WEEKDAYS] = tm->tm_wday; 168 buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1); 169 buf[DT_YEARS] = bin2bcd(tm->tm_year % 100); 170 171 ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN, 172 tmp, sizeof(tmp)); 173 if (ret) 174 return ret; 175 176 return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0); 177 } 178 179 static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 180 { 181 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 182 unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1]; 183 unsigned int val; 184 int ret; 185 186 ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf, 187 sizeof(buf)); 188 if (ret) 189 return ret; 190 191 alrm->time.tm_sec = bcd2bin(buf[0]); 192 alrm->time.tm_min = bcd2bin(buf[1]); 193 alrm->time.tm_hour = bcd2bin(buf[2]); 194 alrm->time.tm_mday = bcd2bin(buf[3]); 195 alrm->time.tm_mon = bcd2bin(buf[4]) - 1; 196 197 ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val); 198 if (ret) 199 return ret; 200 201 alrm->enabled = !!(val & INT_A1IE); 202 203 return 0; 204 } 205 206 static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned 207 int enabled) 208 { 209 unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E | 210 ALRM_DAY_A1E | ALRM_MON_A1E; 211 int ret; 212 213 ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags, 214 enabled ? alarm_flags : 0); 215 if (ret) 216 return ret; 217 218 ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN, 219 INT_A1IE, enabled ? INT_A1IE : 0); 220 221 if (ret || enabled) 222 return ret; 223 224 /* clear current flags */ 225 return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0); 226 } 227 228 static int pcf85363_rtc_alarm_irq_enable(struct device *dev, 229 unsigned int enabled) 230 { 231 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 232 233 return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled); 234 } 235 236 static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 237 { 238 struct pcf85363 *pcf85363 = dev_get_drvdata(dev); 239 unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1]; 240 int ret; 241 242 buf[0] = bin2bcd(alrm->time.tm_sec); 243 buf[1] = bin2bcd(alrm->time.tm_min); 244 buf[2] = bin2bcd(alrm->time.tm_hour); 245 buf[3] = bin2bcd(alrm->time.tm_mday); 246 buf[4] = bin2bcd(alrm->time.tm_mon + 1); 247 248 /* 249 * Disable the alarm interrupt before changing the value to avoid 250 * spurious interrupts 251 */ 252 ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0); 253 if (ret) 254 return ret; 255 256 ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf, 257 sizeof(buf)); 258 if (ret) 259 return ret; 260 261 return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled); 262 } 263 264 static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id) 265 { 266 struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id); 267 unsigned int flags; 268 int err; 269 270 err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags); 271 if (err) 272 return IRQ_NONE; 273 274 if (flags & FLAGS_A1F) { 275 rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF); 276 regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0); 277 return IRQ_HANDLED; 278 } 279 280 return IRQ_NONE; 281 } 282 283 static const struct rtc_class_ops rtc_ops = { 284 .read_time = pcf85363_rtc_read_time, 285 .set_time = pcf85363_rtc_set_time, 286 }; 287 288 static const struct rtc_class_ops rtc_ops_alarm = { 289 .read_time = pcf85363_rtc_read_time, 290 .set_time = pcf85363_rtc_set_time, 291 .read_alarm = pcf85363_rtc_read_alarm, 292 .set_alarm = pcf85363_rtc_set_alarm, 293 .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable, 294 }; 295 296 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val, 297 size_t bytes) 298 { 299 struct pcf85363 *pcf85363 = priv; 300 301 return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset, 302 val, bytes); 303 } 304 305 static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val, 306 size_t bytes) 307 { 308 struct pcf85363 *pcf85363 = priv; 309 310 return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset, 311 val, bytes); 312 } 313 314 static const struct regmap_config regmap_config = { 315 .reg_bits = 8, 316 .val_bits = 8, 317 .max_register = 0x7f, 318 }; 319 320 static int pcf85363_probe(struct i2c_client *client, 321 const struct i2c_device_id *id) 322 { 323 struct pcf85363 *pcf85363; 324 struct nvmem_config nvmem_cfg = { 325 .name = "pcf85363-", 326 .word_size = 1, 327 .stride = 1, 328 .size = NVRAM_SIZE, 329 .reg_read = pcf85363_nvram_read, 330 .reg_write = pcf85363_nvram_write, 331 }; 332 int ret; 333 334 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 335 return -ENODEV; 336 337 pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363), 338 GFP_KERNEL); 339 if (!pcf85363) 340 return -ENOMEM; 341 342 pcf85363->regmap = devm_regmap_init_i2c(client, ®map_config); 343 if (IS_ERR(pcf85363->regmap)) { 344 dev_err(&client->dev, "regmap allocation failed\n"); 345 return PTR_ERR(pcf85363->regmap); 346 } 347 348 pcf85363->dev = &client->dev; 349 i2c_set_clientdata(client, pcf85363); 350 351 pcf85363->rtc = devm_rtc_allocate_device(pcf85363->dev); 352 if (IS_ERR(pcf85363->rtc)) 353 return PTR_ERR(pcf85363->rtc); 354 355 pcf85363->rtc->ops = &rtc_ops; 356 357 if (client->irq > 0) { 358 regmap_write(pcf85363->regmap, CTRL_FLAGS, 0); 359 regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO, 360 PIN_IO_INTA_OUT, PIN_IO_INTAPM); 361 ret = devm_request_threaded_irq(pcf85363->dev, client->irq, 362 NULL, pcf85363_rtc_handle_irq, 363 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 364 "pcf85363", client); 365 if (ret) 366 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); 367 else 368 pcf85363->rtc->ops = &rtc_ops_alarm; 369 } 370 371 ret = rtc_register_device(pcf85363->rtc); 372 373 nvmem_cfg.priv = pcf85363; 374 rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg); 375 376 return ret; 377 } 378 379 static const struct of_device_id dev_ids[] = { 380 { .compatible = "nxp,pcf85363" }, 381 {} 382 }; 383 MODULE_DEVICE_TABLE(of, dev_ids); 384 385 static struct i2c_driver pcf85363_driver = { 386 .driver = { 387 .name = "pcf85363", 388 .of_match_table = of_match_ptr(dev_ids), 389 }, 390 .probe = pcf85363_probe, 391 }; 392 393 module_i2c_driver(pcf85363_driver); 394 395 MODULE_AUTHOR("Eric Nelson"); 396 MODULE_DESCRIPTION("pcf85363 I2C RTC driver"); 397 MODULE_LICENSE("GPL"); 398