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 = bcd2bin(alarmvals[2] & 0x7f); 277 278 t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE); 279 t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled; 280 281 return err; 282 } 283 284 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t) 285 { 286 struct i2c_client *client = to_i2c_client(dev); 287 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 288 u8 alarmvals[3]; 289 int extreg, flagreg; 290 int err; 291 unsigned long irqflags; 292 293 spin_lock_irqsave(&rx8010->flags_lock, irqflags); 294 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 295 if (flagreg < 0) { 296 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 297 return flagreg; 298 } 299 300 if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) { 301 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE); 302 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 303 rx8010->ctrlreg); 304 if (err < 0) { 305 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 306 return err; 307 } 308 } 309 310 flagreg &= ~RX8010_FLAG_AF; 311 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); 312 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 313 if (err < 0) 314 return err; 315 316 alarmvals[0] = bin2bcd(t->time.tm_min); 317 alarmvals[1] = bin2bcd(t->time.tm_hour); 318 alarmvals[2] = bin2bcd(t->time.tm_mday); 319 320 err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN, 321 2, alarmvals); 322 if (err < 0) 323 return err; 324 325 extreg = i2c_smbus_read_byte_data(client, RX8010_EXT); 326 if (extreg < 0) 327 return extreg; 328 329 extreg |= RX8010_EXT_WADA; 330 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg); 331 if (err < 0) 332 return err; 333 334 if (alarmvals[2] == 0) 335 alarmvals[2] |= RX8010_ALARM_AE; 336 337 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY, 338 alarmvals[2]); 339 if (err < 0) 340 return err; 341 342 if (t->enabled) { 343 if (rx8010->rtc->uie_rtctimer.enabled) 344 rx8010->ctrlreg |= RX8010_CTRL_UIE; 345 if (rx8010->rtc->aie_timer.enabled) 346 rx8010->ctrlreg |= 347 (RX8010_CTRL_AIE | RX8010_CTRL_UIE); 348 349 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 350 rx8010->ctrlreg); 351 if (err < 0) 352 return err; 353 } 354 355 return 0; 356 } 357 358 static int rx8010_alarm_irq_enable(struct device *dev, 359 unsigned int enabled) 360 { 361 struct i2c_client *client = to_i2c_client(dev); 362 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 363 int flagreg; 364 u8 ctrl; 365 int err; 366 367 ctrl = rx8010->ctrlreg; 368 369 if (enabled) { 370 if (rx8010->rtc->uie_rtctimer.enabled) 371 ctrl |= RX8010_CTRL_UIE; 372 if (rx8010->rtc->aie_timer.enabled) 373 ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE); 374 } else { 375 if (!rx8010->rtc->uie_rtctimer.enabled) 376 ctrl &= ~RX8010_CTRL_UIE; 377 if (!rx8010->rtc->aie_timer.enabled) 378 ctrl &= ~RX8010_CTRL_AIE; 379 } 380 381 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 382 if (flagreg < 0) 383 return flagreg; 384 385 flagreg &= ~RX8010_FLAG_AF; 386 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); 387 if (err < 0) 388 return err; 389 390 if (ctrl != rx8010->ctrlreg) { 391 rx8010->ctrlreg = ctrl; 392 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 393 rx8010->ctrlreg); 394 if (err < 0) 395 return err; 396 } 397 398 return 0; 399 } 400 401 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 402 { 403 struct i2c_client *client = to_i2c_client(dev); 404 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 405 int ret, tmp; 406 int flagreg; 407 unsigned long irqflags; 408 409 switch (cmd) { 410 case RTC_VL_READ: 411 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 412 if (flagreg < 0) 413 return flagreg; 414 415 tmp = !!(flagreg & RX8010_FLAG_VLF); 416 if (copy_to_user((void __user *)arg, &tmp, sizeof(int))) 417 return -EFAULT; 418 419 return 0; 420 421 case RTC_VL_CLR: 422 spin_lock_irqsave(&rx8010->flags_lock, irqflags); 423 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 424 if (flagreg < 0) { 425 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 426 return flagreg; 427 } 428 429 flagreg &= ~RX8010_FLAG_VLF; 430 ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); 431 spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); 432 if (ret < 0) 433 return ret; 434 435 return 0; 436 437 default: 438 return -ENOIOCTLCMD; 439 } 440 } 441 442 static struct rtc_class_ops rx8010_rtc_ops = { 443 .read_time = rx8010_get_time, 444 .set_time = rx8010_set_time, 445 .ioctl = rx8010_ioctl, 446 }; 447 448 static int rx8010_probe(struct i2c_client *client, 449 const struct i2c_device_id *id) 450 { 451 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 452 struct rx8010_data *rx8010; 453 int err = 0; 454 455 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 456 | I2C_FUNC_SMBUS_I2C_BLOCK)) { 457 dev_err(&adapter->dev, "doesn't support required functionality\n"); 458 return -EIO; 459 } 460 461 rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data), 462 GFP_KERNEL); 463 if (!rx8010) 464 return -ENOMEM; 465 466 rx8010->client = client; 467 i2c_set_clientdata(client, rx8010); 468 469 spin_lock_init(&rx8010->flags_lock); 470 471 err = rx8010_init_client(client); 472 if (err) 473 return err; 474 475 if (client->irq > 0) { 476 dev_info(&client->dev, "IRQ %d supplied\n", client->irq); 477 err = devm_request_threaded_irq(&client->dev, client->irq, NULL, 478 rx8010_irq_1_handler, 479 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 480 "rx8010", client); 481 482 if (err) { 483 dev_err(&client->dev, "unable to request IRQ\n"); 484 client->irq = 0; 485 } else { 486 rx8010_rtc_ops.read_alarm = rx8010_read_alarm; 487 rx8010_rtc_ops.set_alarm = rx8010_set_alarm; 488 rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable; 489 } 490 } 491 492 rx8010->rtc = devm_rtc_device_register(&client->dev, client->name, 493 &rx8010_rtc_ops, THIS_MODULE); 494 495 if (IS_ERR(rx8010->rtc)) { 496 dev_err(&client->dev, "unable to register the class device\n"); 497 return PTR_ERR(rx8010->rtc); 498 } 499 500 rx8010->rtc->max_user_freq = 1; 501 502 return err; 503 } 504 505 static struct i2c_driver rx8010_driver = { 506 .driver = { 507 .name = "rtc-rx8010", 508 }, 509 .probe = rx8010_probe, 510 .id_table = rx8010_id, 511 }; 512 513 module_i2c_driver(rx8010_driver); 514 515 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>"); 516 MODULE_DESCRIPTION("Epson RX8010SJ RTC driver"); 517 MODULE_LICENSE("GPL v2"); 518