1 /* 2 * Driver for the Epson RTC module RX-8010 SJ 3 * 4 * Copyright(C) Timesys Corporation 2015 5 * Copyright(C) General Electric Company 2015 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 */ 12 13 #include <linux/bcd.h> 14 #include <linux/bitops.h> 15 #include <linux/i2c.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/rtc.h> 19 20 #define RX8010_SEC 0x10 21 #define RX8010_MIN 0x11 22 #define RX8010_HOUR 0x12 23 #define RX8010_WDAY 0x13 24 #define RX8010_MDAY 0x14 25 #define RX8010_MONTH 0x15 26 #define RX8010_YEAR 0x16 27 #define RX8010_YEAR 0x16 28 #define RX8010_RESV17 0x17 29 #define RX8010_ALMIN 0x18 30 #define RX8010_ALHOUR 0x19 31 #define RX8010_ALWDAY 0x1A 32 #define RX8010_TCOUNT0 0x1B 33 #define RX8010_TCOUNT1 0x1C 34 #define RX8010_EXT 0x1D 35 #define RX8010_FLAG 0x1E 36 #define RX8010_CTRL 0x1F 37 /* 0x20 to 0x2F are user registers */ 38 #define RX8010_RESV30 0x30 39 #define RX8010_RESV31 0x32 40 #define RX8010_IRQ 0x32 41 42 #define RX8010_EXT_WADA BIT(3) 43 44 #define RX8010_FLAG_VLF BIT(1) 45 #define RX8010_FLAG_AF BIT(3) 46 #define RX8010_FLAG_TF BIT(4) 47 #define RX8010_FLAG_UF BIT(5) 48 49 #define RX8010_CTRL_AIE BIT(3) 50 #define RX8010_CTRL_UIE BIT(5) 51 #define RX8010_CTRL_STOP BIT(6) 52 #define RX8010_CTRL_TEST BIT(7) 53 54 #define RX8010_ALARM_AE BIT(7) 55 56 static const struct i2c_device_id rx8010_id[] = { 57 { "rx8010", 0 }, 58 { } 59 }; 60 MODULE_DEVICE_TABLE(i2c, rx8010_id); 61 62 struct rx8010_data { 63 struct i2c_client *client; 64 struct rtc_device *rtc; 65 u8 ctrlreg; 66 spinlock_t flags_lock; 67 }; 68 69 static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id) 70 { 71 struct i2c_client *client = dev_id; 72 struct rx8010_data *rx8010 = i2c_get_clientdata(client); 73 int flagreg; 74 75 spin_lock(&rx8010->flags_lock); 76 77 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 78 79 if (flagreg <= 0) { 80 spin_unlock(&rx8010->flags_lock); 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 i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); 103 104 spin_unlock(&rx8010->flags_lock); 105 return IRQ_HANDLED; 106 } 107 108 static int rx8010_get_time(struct device *dev, struct rtc_time *dt) 109 { 110 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 111 u8 date[7]; 112 int flagreg; 113 int err; 114 115 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 116 if (flagreg < 0) 117 return flagreg; 118 119 if (flagreg & RX8010_FLAG_VLF) { 120 dev_warn(dev, "Frequency stop detected\n"); 121 return -EINVAL; 122 } 123 124 err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC, 125 7, date); 126 if (err != 7) 127 return err < 0 ? err : -EIO; 128 129 dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f); 130 dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f); 131 dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f); 132 dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f); 133 dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1; 134 dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100; 135 dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f); 136 137 return rtc_valid_tm(dt); 138 } 139 140 static int rx8010_set_time(struct device *dev, struct rtc_time *dt) 141 { 142 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 143 u8 date[7]; 144 int ctrl, flagreg; 145 int ret; 146 unsigned long irqflags; 147 148 if ((dt->tm_year < 100) || (dt->tm_year > 199)) 149 return -EINVAL; 150 151 /* set STOP bit before changing clock/calendar */ 152 ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL); 153 if (ctrl < 0) 154 return ctrl; 155 rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP; 156 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 157 rx8010->ctrlreg); 158 if (ret < 0) 159 return ret; 160 161 date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec); 162 date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min); 163 date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour); 164 date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday); 165 date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1); 166 date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100); 167 date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday); 168 169 ret = i2c_smbus_write_i2c_block_data(rx8010->client, 170 RX8010_SEC, 7, date); 171 if (ret < 0) 172 return ret; 173 174 /* clear STOP bit after changing clock/calendar */ 175 ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL); 176 if (ctrl < 0) 177 return ctrl; 178 rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP; 179 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 180 rx8010->ctrlreg); 181 if (ret < 0) 182 return ret; 183 184 spin_lock_irqsave(&rx8010->flags_lock, irqflags); 185 186 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 187 if (flagreg < 0) { 188 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 189 return flagreg; 190 } 191 192 if (flagreg & RX8010_FLAG_VLF) 193 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, 194 flagreg & ~RX8010_FLAG_VLF); 195 196 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 197 198 return 0; 199 } 200 201 static int rx8010_init_client(struct i2c_client *client) 202 { 203 struct rx8010_data *rx8010 = i2c_get_clientdata(client); 204 u8 ctrl[2]; 205 int need_clear = 0, err = 0; 206 207 /* Initialize reserved registers as specified in datasheet */ 208 err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8); 209 if (err < 0) 210 return err; 211 212 err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00); 213 if (err < 0) 214 return err; 215 216 err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08); 217 if (err < 0) 218 return err; 219 220 err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00); 221 if (err < 0) 222 return err; 223 224 err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG, 225 2, ctrl); 226 if (err != 2) 227 return err < 0 ? err : -EIO; 228 229 if (ctrl[0] & RX8010_FLAG_VLF) 230 dev_warn(&client->dev, "Frequency stop was detected\n"); 231 232 if (ctrl[0] & RX8010_FLAG_AF) { 233 dev_warn(&client->dev, "Alarm was detected\n"); 234 need_clear = 1; 235 } 236 237 if (ctrl[0] & RX8010_FLAG_TF) 238 need_clear = 1; 239 240 if (ctrl[0] & RX8010_FLAG_UF) 241 need_clear = 1; 242 243 if (need_clear) { 244 ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF); 245 err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]); 246 if (err < 0) 247 return err; 248 } 249 250 rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST); 251 252 return err; 253 } 254 255 static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t) 256 { 257 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 258 struct i2c_client *client = rx8010->client; 259 u8 alarmvals[3]; 260 int flagreg; 261 int err; 262 263 err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals); 264 if (err != 3) 265 return err < 0 ? err : -EIO; 266 267 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 268 if (flagreg < 0) 269 return flagreg; 270 271 t->time.tm_sec = 0; 272 t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); 273 t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); 274 275 if (alarmvals[2] & RX8010_ALARM_AE) 276 t->time.tm_mday = -1; 277 else 278 t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f); 279 280 t->time.tm_wday = -1; 281 t->time.tm_mon = -1; 282 t->time.tm_year = -1; 283 284 t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE); 285 t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled; 286 287 return err; 288 } 289 290 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t) 291 { 292 struct i2c_client *client = to_i2c_client(dev); 293 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 294 u8 alarmvals[3]; 295 int extreg, flagreg; 296 int err; 297 unsigned long irqflags; 298 299 spin_lock_irqsave(&rx8010->flags_lock, irqflags); 300 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 301 if (flagreg < 0) { 302 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 303 return flagreg; 304 } 305 306 if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) { 307 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE); 308 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 309 rx8010->ctrlreg); 310 if (err < 0) { 311 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 312 return err; 313 } 314 } 315 316 flagreg &= ~RX8010_FLAG_AF; 317 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); 318 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 319 if (err < 0) 320 return err; 321 322 alarmvals[0] = bin2bcd(t->time.tm_min); 323 alarmvals[1] = bin2bcd(t->time.tm_hour); 324 alarmvals[2] = bin2bcd(t->time.tm_mday); 325 326 err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN, 327 2, alarmvals); 328 if (err < 0) 329 return err; 330 331 extreg = i2c_smbus_read_byte_data(client, RX8010_EXT); 332 if (extreg < 0) 333 return extreg; 334 335 extreg |= RX8010_EXT_WADA; 336 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg); 337 if (err < 0) 338 return err; 339 340 if (alarmvals[2] == 0) 341 alarmvals[2] |= RX8010_ALARM_AE; 342 343 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY, 344 alarmvals[2]); 345 if (err < 0) 346 return err; 347 348 if (t->enabled) { 349 if (rx8010->rtc->uie_rtctimer.enabled) 350 rx8010->ctrlreg |= RX8010_CTRL_UIE; 351 if (rx8010->rtc->aie_timer.enabled) 352 rx8010->ctrlreg |= 353 (RX8010_CTRL_AIE | RX8010_CTRL_UIE); 354 355 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 356 rx8010->ctrlreg); 357 if (err < 0) 358 return err; 359 } 360 361 return 0; 362 } 363 364 static int rx8010_alarm_irq_enable(struct device *dev, 365 unsigned int enabled) 366 { 367 struct i2c_client *client = to_i2c_client(dev); 368 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 369 int flagreg; 370 u8 ctrl; 371 int err; 372 373 ctrl = rx8010->ctrlreg; 374 375 if (enabled) { 376 if (rx8010->rtc->uie_rtctimer.enabled) 377 ctrl |= RX8010_CTRL_UIE; 378 if (rx8010->rtc->aie_timer.enabled) 379 ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE); 380 } else { 381 if (!rx8010->rtc->uie_rtctimer.enabled) 382 ctrl &= ~RX8010_CTRL_UIE; 383 if (!rx8010->rtc->aie_timer.enabled) 384 ctrl &= ~RX8010_CTRL_AIE; 385 } 386 387 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 388 if (flagreg < 0) 389 return flagreg; 390 391 flagreg &= ~RX8010_FLAG_AF; 392 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); 393 if (err < 0) 394 return err; 395 396 if (ctrl != rx8010->ctrlreg) { 397 rx8010->ctrlreg = ctrl; 398 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 399 rx8010->ctrlreg); 400 if (err < 0) 401 return err; 402 } 403 404 return 0; 405 } 406 407 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 408 { 409 struct i2c_client *client = to_i2c_client(dev); 410 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 411 int ret, tmp; 412 int flagreg; 413 unsigned long irqflags; 414 415 switch (cmd) { 416 case RTC_VL_READ: 417 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 418 if (flagreg < 0) 419 return flagreg; 420 421 tmp = !!(flagreg & RX8010_FLAG_VLF); 422 if (copy_to_user((void __user *)arg, &tmp, sizeof(int))) 423 return -EFAULT; 424 425 return 0; 426 427 case RTC_VL_CLR: 428 spin_lock_irqsave(&rx8010->flags_lock, irqflags); 429 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 430 if (flagreg < 0) { 431 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 432 return flagreg; 433 } 434 435 flagreg &= ~RX8010_FLAG_VLF; 436 ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); 437 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 438 if (ret < 0) 439 return ret; 440 441 return 0; 442 443 default: 444 return -ENOIOCTLCMD; 445 } 446 } 447 448 static struct rtc_class_ops rx8010_rtc_ops = { 449 .read_time = rx8010_get_time, 450 .set_time = rx8010_set_time, 451 .ioctl = rx8010_ioctl, 452 }; 453 454 static int rx8010_probe(struct i2c_client *client, 455 const struct i2c_device_id *id) 456 { 457 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 458 struct rx8010_data *rx8010; 459 int err = 0; 460 461 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 462 | I2C_FUNC_SMBUS_I2C_BLOCK)) { 463 dev_err(&adapter->dev, "doesn't support required functionality\n"); 464 return -EIO; 465 } 466 467 rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data), 468 GFP_KERNEL); 469 if (!rx8010) 470 return -ENOMEM; 471 472 rx8010->client = client; 473 i2c_set_clientdata(client, rx8010); 474 475 spin_lock_init(&rx8010->flags_lock); 476 477 err = rx8010_init_client(client); 478 if (err) 479 return err; 480 481 if (client->irq > 0) { 482 dev_info(&client->dev, "IRQ %d supplied\n", client->irq); 483 err = devm_request_threaded_irq(&client->dev, client->irq, NULL, 484 rx8010_irq_1_handler, 485 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 486 "rx8010", client); 487 488 if (err) { 489 dev_err(&client->dev, "unable to request IRQ\n"); 490 client->irq = 0; 491 } else { 492 rx8010_rtc_ops.read_alarm = rx8010_read_alarm; 493 rx8010_rtc_ops.set_alarm = rx8010_set_alarm; 494 rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable; 495 } 496 } 497 498 rx8010->rtc = devm_rtc_device_register(&client->dev, client->name, 499 &rx8010_rtc_ops, THIS_MODULE); 500 501 if (IS_ERR(rx8010->rtc)) { 502 dev_err(&client->dev, "unable to register the class device\n"); 503 return PTR_ERR(rx8010->rtc); 504 } 505 506 rx8010->rtc->max_user_freq = 1; 507 508 return err; 509 } 510 511 static struct i2c_driver rx8010_driver = { 512 .driver = { 513 .name = "rtc-rx8010", 514 }, 515 .probe = rx8010_probe, 516 .id_table = rx8010_id, 517 }; 518 519 module_i2c_driver(rx8010_driver); 520 521 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>"); 522 MODULE_DESCRIPTION("Epson RX8010SJ RTC driver"); 523 MODULE_LICENSE("GPL v2"); 524