1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for the Epson RTC module RX-6110 SA 4 * 5 * Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de> 6 * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved. 7 */ 8 9 #include <linux/bcd.h> 10 #include <linux/init.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/of_gpio.h> 14 #include <linux/regmap.h> 15 #include <linux/rtc.h> 16 #include <linux/of.h> 17 #include <linux/of_device.h> 18 #include <linux/spi/spi.h> 19 #include <linux/i2c.h> 20 21 /* RX-6110 Register definitions */ 22 #define RX6110_REG_SEC 0x10 23 #define RX6110_REG_MIN 0x11 24 #define RX6110_REG_HOUR 0x12 25 #define RX6110_REG_WDAY 0x13 26 #define RX6110_REG_MDAY 0x14 27 #define RX6110_REG_MONTH 0x15 28 #define RX6110_REG_YEAR 0x16 29 #define RX6110_REG_RES1 0x17 30 #define RX6110_REG_ALMIN 0x18 31 #define RX6110_REG_ALHOUR 0x19 32 #define RX6110_REG_ALWDAY 0x1A 33 #define RX6110_REG_TCOUNT0 0x1B 34 #define RX6110_REG_TCOUNT1 0x1C 35 #define RX6110_REG_EXT 0x1D 36 #define RX6110_REG_FLAG 0x1E 37 #define RX6110_REG_CTRL 0x1F 38 #define RX6110_REG_USER0 0x20 39 #define RX6110_REG_USER1 0x21 40 #define RX6110_REG_USER2 0x22 41 #define RX6110_REG_USER3 0x23 42 #define RX6110_REG_USER4 0x24 43 #define RX6110_REG_USER5 0x25 44 #define RX6110_REG_USER6 0x26 45 #define RX6110_REG_USER7 0x27 46 #define RX6110_REG_USER8 0x28 47 #define RX6110_REG_USER9 0x29 48 #define RX6110_REG_USERA 0x2A 49 #define RX6110_REG_USERB 0x2B 50 #define RX6110_REG_USERC 0x2C 51 #define RX6110_REG_USERD 0x2D 52 #define RX6110_REG_USERE 0x2E 53 #define RX6110_REG_USERF 0x2F 54 #define RX6110_REG_RES2 0x30 55 #define RX6110_REG_RES3 0x31 56 #define RX6110_REG_IRQ 0x32 57 58 #define RX6110_BIT_ALARM_EN BIT(7) 59 60 /* Extension Register (1Dh) bit positions */ 61 #define RX6110_BIT_EXT_TSEL0 BIT(0) 62 #define RX6110_BIT_EXT_TSEL1 BIT(1) 63 #define RX6110_BIT_EXT_TSEL2 BIT(2) 64 #define RX6110_BIT_EXT_WADA BIT(3) 65 #define RX6110_BIT_EXT_TE BIT(4) 66 #define RX6110_BIT_EXT_USEL BIT(5) 67 #define RX6110_BIT_EXT_FSEL0 BIT(6) 68 #define RX6110_BIT_EXT_FSEL1 BIT(7) 69 70 /* Flag Register (1Eh) bit positions */ 71 #define RX6110_BIT_FLAG_VLF BIT(1) 72 #define RX6110_BIT_FLAG_AF BIT(3) 73 #define RX6110_BIT_FLAG_TF BIT(4) 74 #define RX6110_BIT_FLAG_UF BIT(5) 75 76 /* Control Register (1Fh) bit positions */ 77 #define RX6110_BIT_CTRL_TBKE BIT(0) 78 #define RX6110_BIT_CTRL_TBKON BIT(1) 79 #define RX6110_BIT_CTRL_TSTP BIT(2) 80 #define RX6110_BIT_CTRL_AIE BIT(3) 81 #define RX6110_BIT_CTRL_TIE BIT(4) 82 #define RX6110_BIT_CTRL_UIE BIT(5) 83 #define RX6110_BIT_CTRL_STOP BIT(6) 84 #define RX6110_BIT_CTRL_TEST BIT(7) 85 86 enum { 87 RTC_SEC = 0, 88 RTC_MIN, 89 RTC_HOUR, 90 RTC_WDAY, 91 RTC_MDAY, 92 RTC_MONTH, 93 RTC_YEAR, 94 RTC_NR_TIME 95 }; 96 97 #define RX6110_DRIVER_NAME "rx6110" 98 99 struct rx6110_data { 100 struct rtc_device *rtc; 101 struct regmap *regmap; 102 }; 103 104 /** 105 * rx6110_rtc_tm_to_data - convert rtc_time to native time encoding 106 * 107 * @tm: holds date and time 108 * @data: holds the encoding in rx6110 native form 109 */ 110 static int rx6110_rtc_tm_to_data(struct rtc_time *tm, u8 *data) 111 { 112 pr_debug("%s: date %ptRr\n", __func__, tm); 113 114 /* 115 * The year in the RTC is a value between 0 and 99. 116 * Assume that this represents the current century 117 * and disregard all other values. 118 */ 119 if (tm->tm_year < 100 || tm->tm_year >= 200) 120 return -EINVAL; 121 122 data[RTC_SEC] = bin2bcd(tm->tm_sec); 123 data[RTC_MIN] = bin2bcd(tm->tm_min); 124 data[RTC_HOUR] = bin2bcd(tm->tm_hour); 125 data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday)); 126 data[RTC_MDAY] = bin2bcd(tm->tm_mday); 127 data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1); 128 data[RTC_YEAR] = bin2bcd(tm->tm_year % 100); 129 130 return 0; 131 } 132 133 /** 134 * rx6110_data_to_rtc_tm - convert native time encoding to rtc_time 135 * 136 * @data: holds the encoding in rx6110 native form 137 * @tm: holds date and time 138 */ 139 static int rx6110_data_to_rtc_tm(u8 *data, struct rtc_time *tm) 140 { 141 tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f); 142 tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f); 143 /* only 24-hour clock */ 144 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f); 145 tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f); 146 tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f); 147 tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1; 148 tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100; 149 150 pr_debug("%s: date %ptRr\n", __func__, tm); 151 152 /* 153 * The year in the RTC is a value between 0 and 99. 154 * Assume that this represents the current century 155 * and disregard all other values. 156 */ 157 if (tm->tm_year < 100 || tm->tm_year >= 200) 158 return -EINVAL; 159 160 return 0; 161 } 162 163 /** 164 * rx6110_set_time - set the current time in the rx6110 registers 165 * 166 * @dev: the rtc device in use 167 * @tm: holds date and time 168 * 169 * BUG: The HW assumes every year that is a multiple of 4 to be a leap 170 * year. Next time this is wrong is 2100, which will not be a leap year 171 * 172 * Note: If STOP is not set/cleared, the clock will start when the seconds 173 * register is written 174 * 175 */ 176 static int rx6110_set_time(struct device *dev, struct rtc_time *tm) 177 { 178 struct rx6110_data *rx6110 = dev_get_drvdata(dev); 179 u8 data[RTC_NR_TIME]; 180 int ret; 181 182 ret = rx6110_rtc_tm_to_data(tm, data); 183 if (ret < 0) 184 return ret; 185 186 /* set STOP bit before changing clock/calendar */ 187 ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL, 188 RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP); 189 if (ret) 190 return ret; 191 192 ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data, 193 RTC_NR_TIME); 194 if (ret) 195 return ret; 196 197 /* The time in the RTC is valid. Be sure to have VLF cleared. */ 198 ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG, 199 RX6110_BIT_FLAG_VLF, 0); 200 if (ret) 201 return ret; 202 203 /* clear STOP bit after changing clock/calendar */ 204 ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL, 205 RX6110_BIT_CTRL_STOP, 0); 206 207 return ret; 208 } 209 210 /** 211 * rx6110_get_time - get the current time from the rx6110 registers 212 * @dev: the rtc device in use 213 * @tm: holds date and time 214 */ 215 static int rx6110_get_time(struct device *dev, struct rtc_time *tm) 216 { 217 struct rx6110_data *rx6110 = dev_get_drvdata(dev); 218 u8 data[RTC_NR_TIME]; 219 int flags; 220 int ret; 221 222 ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags); 223 if (ret) 224 return -EINVAL; 225 226 /* check for VLF Flag (set at power-on) */ 227 if ((flags & RX6110_BIT_FLAG_VLF)) { 228 dev_warn(dev, "Voltage low, data is invalid.\n"); 229 return -EINVAL; 230 } 231 232 /* read registers to date */ 233 ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data, 234 RTC_NR_TIME); 235 if (ret) 236 return ret; 237 238 ret = rx6110_data_to_rtc_tm(data, tm); 239 if (ret) 240 return ret; 241 242 dev_dbg(dev, "%s: date %ptRr\n", __func__, tm); 243 244 return 0; 245 } 246 247 static const struct reg_sequence rx6110_default_regs[] = { 248 { RX6110_REG_RES1, 0xB8 }, 249 { RX6110_REG_RES2, 0x00 }, 250 { RX6110_REG_RES3, 0x10 }, 251 { RX6110_REG_IRQ, 0x00 }, 252 { RX6110_REG_ALMIN, 0x00 }, 253 { RX6110_REG_ALHOUR, 0x00 }, 254 { RX6110_REG_ALWDAY, 0x00 }, 255 }; 256 257 /** 258 * rx6110_init - initialize the rx6110 registers 259 * 260 * @rx6110: pointer to the rx6110 struct in use 261 * 262 */ 263 static int rx6110_init(struct rx6110_data *rx6110) 264 { 265 struct rtc_device *rtc = rx6110->rtc; 266 int flags; 267 int ret; 268 269 ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT, 270 RX6110_BIT_EXT_TE, 0); 271 if (ret) 272 return ret; 273 274 ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs, 275 ARRAY_SIZE(rx6110_default_regs)); 276 if (ret) 277 return ret; 278 279 ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags); 280 if (ret) 281 return ret; 282 283 /* check for VLF Flag (set at power-on) */ 284 if ((flags & RX6110_BIT_FLAG_VLF)) 285 dev_warn(&rtc->dev, "Voltage low, data loss detected.\n"); 286 287 /* check for Alarm Flag */ 288 if (flags & RX6110_BIT_FLAG_AF) 289 dev_warn(&rtc->dev, "An alarm may have been missed.\n"); 290 291 /* check for Periodic Timer Flag */ 292 if (flags & RX6110_BIT_FLAG_TF) 293 dev_warn(&rtc->dev, "Periodic timer was detected\n"); 294 295 /* check for Update Timer Flag */ 296 if (flags & RX6110_BIT_FLAG_UF) 297 dev_warn(&rtc->dev, "Update timer was detected\n"); 298 299 /* clear all flags BUT VLF */ 300 ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG, 301 RX6110_BIT_FLAG_AF | 302 RX6110_BIT_FLAG_UF | 303 RX6110_BIT_FLAG_TF, 304 0); 305 306 return ret; 307 } 308 309 static const struct rtc_class_ops rx6110_rtc_ops = { 310 .read_time = rx6110_get_time, 311 .set_time = rx6110_set_time, 312 }; 313 314 static int rx6110_probe(struct rx6110_data *rx6110, struct device *dev) 315 { 316 int err; 317 318 rx6110->rtc = devm_rtc_device_register(dev, 319 RX6110_DRIVER_NAME, 320 &rx6110_rtc_ops, THIS_MODULE); 321 322 if (IS_ERR(rx6110->rtc)) 323 return PTR_ERR(rx6110->rtc); 324 325 err = rx6110_init(rx6110); 326 if (err) 327 return err; 328 329 rx6110->rtc->max_user_freq = 1; 330 331 return 0; 332 } 333 334 #if IS_ENABLED(CONFIG_SPI_MASTER) 335 static struct regmap_config regmap_spi_config = { 336 .reg_bits = 8, 337 .val_bits = 8, 338 .max_register = RX6110_REG_IRQ, 339 .read_flag_mask = 0x80, 340 }; 341 342 /** 343 * rx6110_spi_probe - initialize rtc driver 344 * @spi: pointer to spi device 345 */ 346 static int rx6110_spi_probe(struct spi_device *spi) 347 { 348 struct rx6110_data *rx6110; 349 350 if ((spi->bits_per_word && spi->bits_per_word != 8) || 351 (spi->max_speed_hz > 2000000) || 352 (spi->mode != (SPI_CS_HIGH | SPI_CPOL | SPI_CPHA))) { 353 dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n", 354 spi->bits_per_word, spi->max_speed_hz, spi->mode); 355 dev_warn(&spi->dev, "driving device in an unsupported mode"); 356 } 357 358 rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL); 359 if (!rx6110) 360 return -ENOMEM; 361 362 rx6110->regmap = devm_regmap_init_spi(spi, ®map_spi_config); 363 if (IS_ERR(rx6110->regmap)) { 364 dev_err(&spi->dev, "regmap init failed for rtc rx6110\n"); 365 return PTR_ERR(rx6110->regmap); 366 } 367 368 spi_set_drvdata(spi, rx6110); 369 370 return rx6110_probe(rx6110, &spi->dev); 371 } 372 373 static const struct spi_device_id rx6110_spi_id[] = { 374 { "rx6110", 0 }, 375 { } 376 }; 377 MODULE_DEVICE_TABLE(spi, rx6110_spi_id); 378 379 static const struct of_device_id rx6110_spi_of_match[] = { 380 { .compatible = "epson,rx6110" }, 381 { }, 382 }; 383 MODULE_DEVICE_TABLE(of, rx6110_spi_of_match); 384 385 static struct spi_driver rx6110_spi_driver = { 386 .driver = { 387 .name = RX6110_DRIVER_NAME, 388 .of_match_table = of_match_ptr(rx6110_spi_of_match), 389 }, 390 .probe = rx6110_spi_probe, 391 .id_table = rx6110_spi_id, 392 }; 393 394 static int rx6110_spi_register(void) 395 { 396 return spi_register_driver(&rx6110_spi_driver); 397 } 398 399 static void rx6110_spi_unregister(void) 400 { 401 spi_unregister_driver(&rx6110_spi_driver); 402 } 403 #else 404 static int rx6110_spi_register(void) 405 { 406 return 0; 407 } 408 409 static void rx6110_spi_unregister(void) 410 { 411 } 412 #endif /* CONFIG_SPI_MASTER */ 413 414 #if IS_ENABLED(CONFIG_I2C) 415 static struct regmap_config regmap_i2c_config = { 416 .reg_bits = 8, 417 .val_bits = 8, 418 .max_register = RX6110_REG_IRQ, 419 .read_flag_mask = 0x80, 420 }; 421 422 static int rx6110_i2c_probe(struct i2c_client *client, 423 const struct i2c_device_id *id) 424 { 425 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 426 struct rx6110_data *rx6110; 427 428 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 429 | I2C_FUNC_SMBUS_I2C_BLOCK)) { 430 dev_err(&adapter->dev, 431 "doesn't support required functionality\n"); 432 return -EIO; 433 } 434 435 rx6110 = devm_kzalloc(&client->dev, sizeof(*rx6110), GFP_KERNEL); 436 if (!rx6110) 437 return -ENOMEM; 438 439 rx6110->regmap = devm_regmap_init_i2c(client, ®map_i2c_config); 440 if (IS_ERR(rx6110->regmap)) { 441 dev_err(&client->dev, "regmap init failed for rtc rx6110\n"); 442 return PTR_ERR(rx6110->regmap); 443 } 444 445 i2c_set_clientdata(client, rx6110); 446 447 return rx6110_probe(rx6110, &client->dev); 448 } 449 450 static const struct i2c_device_id rx6110_i2c_id[] = { 451 { "rx6110", 0 }, 452 { } 453 }; 454 MODULE_DEVICE_TABLE(i2c, rx6110_i2c_id); 455 456 static struct i2c_driver rx6110_i2c_driver = { 457 .driver = { 458 .name = RX6110_DRIVER_NAME, 459 }, 460 .probe = rx6110_i2c_probe, 461 .id_table = rx6110_i2c_id, 462 }; 463 464 static int rx6110_i2c_register(void) 465 { 466 return i2c_add_driver(&rx6110_i2c_driver); 467 } 468 469 static void rx6110_i2c_unregister(void) 470 { 471 i2c_del_driver(&rx6110_i2c_driver); 472 } 473 #else 474 static int rx6110_i2c_register(void) 475 { 476 return 0; 477 } 478 479 static void rx6110_i2c_unregister(void) 480 { 481 } 482 #endif /* CONFIG_I2C */ 483 484 static int __init rx6110_module_init(void) 485 { 486 int ret; 487 488 ret = rx6110_spi_register(); 489 if (ret) 490 return ret; 491 492 ret = rx6110_i2c_register(); 493 if (ret) 494 rx6110_spi_unregister(); 495 496 return ret; 497 } 498 module_init(rx6110_module_init); 499 500 static void __exit rx6110_module_exit(void) 501 { 502 rx6110_spi_unregister(); 503 rx6110_i2c_unregister(); 504 } 505 module_exit(rx6110_module_exit); 506 507 MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>"); 508 MODULE_DESCRIPTION("RX-6110 SA RTC driver"); 509 MODULE_LICENSE("GPL"); 510