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 static const struct of_device_id rx8010_of_match[] = { 63 { .compatible = "epson,rx8010" }, 64 { } 65 }; 66 MODULE_DEVICE_TABLE(of, rx8010_of_match); 67 68 struct rx8010_data { 69 struct i2c_client *client; 70 struct rtc_device *rtc; 71 u8 ctrlreg; 72 }; 73 74 static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id) 75 { 76 struct i2c_client *client = dev_id; 77 struct rx8010_data *rx8010 = i2c_get_clientdata(client); 78 int flagreg; 79 80 mutex_lock(&rx8010->rtc->ops_lock); 81 82 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 83 84 if (flagreg <= 0) { 85 mutex_unlock(&rx8010->rtc->ops_lock); 86 return IRQ_NONE; 87 } 88 89 if (flagreg & RX8010_FLAG_VLF) 90 dev_warn(&client->dev, "Frequency stop detected\n"); 91 92 if (flagreg & RX8010_FLAG_TF) { 93 flagreg &= ~RX8010_FLAG_TF; 94 rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF); 95 } 96 97 if (flagreg & RX8010_FLAG_AF) { 98 flagreg &= ~RX8010_FLAG_AF; 99 rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF); 100 } 101 102 if (flagreg & RX8010_FLAG_UF) { 103 flagreg &= ~RX8010_FLAG_UF; 104 rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF); 105 } 106 107 i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); 108 109 mutex_unlock(&rx8010->rtc->ops_lock); 110 return IRQ_HANDLED; 111 } 112 113 static int rx8010_get_time(struct device *dev, struct rtc_time *dt) 114 { 115 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 116 u8 date[7]; 117 int flagreg; 118 int err; 119 120 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 121 if (flagreg < 0) 122 return flagreg; 123 124 if (flagreg & RX8010_FLAG_VLF) { 125 dev_warn(dev, "Frequency stop detected\n"); 126 return -EINVAL; 127 } 128 129 err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC, 130 7, date); 131 if (err != 7) 132 return err < 0 ? err : -EIO; 133 134 dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f); 135 dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f); 136 dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f); 137 dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f); 138 dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1; 139 dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100; 140 dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f); 141 142 return rtc_valid_tm(dt); 143 } 144 145 static int rx8010_set_time(struct device *dev, struct rtc_time *dt) 146 { 147 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 148 u8 date[7]; 149 int ctrl, flagreg; 150 int ret; 151 152 if ((dt->tm_year < 100) || (dt->tm_year > 199)) 153 return -EINVAL; 154 155 /* set STOP bit before changing clock/calendar */ 156 ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL); 157 if (ctrl < 0) 158 return ctrl; 159 rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP; 160 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 161 rx8010->ctrlreg); 162 if (ret < 0) 163 return ret; 164 165 date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec); 166 date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min); 167 date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour); 168 date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday); 169 date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1); 170 date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100); 171 date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday); 172 173 ret = i2c_smbus_write_i2c_block_data(rx8010->client, 174 RX8010_SEC, 7, date); 175 if (ret < 0) 176 return ret; 177 178 /* clear STOP bit after changing clock/calendar */ 179 ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL); 180 if (ctrl < 0) 181 return ctrl; 182 rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP; 183 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 184 rx8010->ctrlreg); 185 if (ret < 0) 186 return ret; 187 188 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 189 if (flagreg < 0) { 190 return flagreg; 191 } 192 193 if (flagreg & RX8010_FLAG_VLF) 194 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, 195 flagreg & ~RX8010_FLAG_VLF); 196 197 return 0; 198 } 199 200 static int rx8010_init_client(struct i2c_client *client) 201 { 202 struct rx8010_data *rx8010 = i2c_get_clientdata(client); 203 u8 ctrl[2]; 204 int need_clear = 0, err = 0; 205 206 /* Initialize reserved registers as specified in datasheet */ 207 err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8); 208 if (err < 0) 209 return err; 210 211 err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00); 212 if (err < 0) 213 return err; 214 215 err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08); 216 if (err < 0) 217 return err; 218 219 err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00); 220 if (err < 0) 221 return err; 222 223 err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG, 224 2, ctrl); 225 if (err != 2) 226 return err < 0 ? err : -EIO; 227 228 if (ctrl[0] & RX8010_FLAG_VLF) 229 dev_warn(&client->dev, "Frequency stop was detected\n"); 230 231 if (ctrl[0] & RX8010_FLAG_AF) { 232 dev_warn(&client->dev, "Alarm was detected\n"); 233 need_clear = 1; 234 } 235 236 if (ctrl[0] & RX8010_FLAG_TF) 237 need_clear = 1; 238 239 if (ctrl[0] & RX8010_FLAG_UF) 240 need_clear = 1; 241 242 if (need_clear) { 243 ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF); 244 err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]); 245 if (err < 0) 246 return err; 247 } 248 249 rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST); 250 251 return err; 252 } 253 254 static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t) 255 { 256 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 257 struct i2c_client *client = rx8010->client; 258 u8 alarmvals[3]; 259 int flagreg; 260 int err; 261 262 err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals); 263 if (err != 3) 264 return err < 0 ? err : -EIO; 265 266 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 267 if (flagreg < 0) 268 return flagreg; 269 270 t->time.tm_sec = 0; 271 t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); 272 t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); 273 274 if (!(alarmvals[2] & RX8010_ALARM_AE)) 275 t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f); 276 277 t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE); 278 t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled; 279 280 return err; 281 } 282 283 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t) 284 { 285 struct i2c_client *client = to_i2c_client(dev); 286 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 287 u8 alarmvals[3]; 288 int extreg, flagreg; 289 int err; 290 291 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 292 if (flagreg < 0) { 293 return flagreg; 294 } 295 296 if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) { 297 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE); 298 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 299 rx8010->ctrlreg); 300 if (err < 0) { 301 return err; 302 } 303 } 304 305 flagreg &= ~RX8010_FLAG_AF; 306 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); 307 if (err < 0) 308 return err; 309 310 alarmvals[0] = bin2bcd(t->time.tm_min); 311 alarmvals[1] = bin2bcd(t->time.tm_hour); 312 alarmvals[2] = bin2bcd(t->time.tm_mday); 313 314 err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN, 315 2, alarmvals); 316 if (err < 0) 317 return err; 318 319 extreg = i2c_smbus_read_byte_data(client, RX8010_EXT); 320 if (extreg < 0) 321 return extreg; 322 323 extreg |= RX8010_EXT_WADA; 324 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg); 325 if (err < 0) 326 return err; 327 328 if (alarmvals[2] == 0) 329 alarmvals[2] |= RX8010_ALARM_AE; 330 331 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY, 332 alarmvals[2]); 333 if (err < 0) 334 return err; 335 336 if (t->enabled) { 337 if (rx8010->rtc->uie_rtctimer.enabled) 338 rx8010->ctrlreg |= RX8010_CTRL_UIE; 339 if (rx8010->rtc->aie_timer.enabled) 340 rx8010->ctrlreg |= 341 (RX8010_CTRL_AIE | RX8010_CTRL_UIE); 342 343 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 344 rx8010->ctrlreg); 345 if (err < 0) 346 return err; 347 } 348 349 return 0; 350 } 351 352 static int rx8010_alarm_irq_enable(struct device *dev, 353 unsigned int enabled) 354 { 355 struct i2c_client *client = to_i2c_client(dev); 356 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 357 int flagreg; 358 u8 ctrl; 359 int err; 360 361 ctrl = rx8010->ctrlreg; 362 363 if (enabled) { 364 if (rx8010->rtc->uie_rtctimer.enabled) 365 ctrl |= RX8010_CTRL_UIE; 366 if (rx8010->rtc->aie_timer.enabled) 367 ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE); 368 } else { 369 if (!rx8010->rtc->uie_rtctimer.enabled) 370 ctrl &= ~RX8010_CTRL_UIE; 371 if (!rx8010->rtc->aie_timer.enabled) 372 ctrl &= ~RX8010_CTRL_AIE; 373 } 374 375 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); 376 if (flagreg < 0) 377 return flagreg; 378 379 flagreg &= ~RX8010_FLAG_AF; 380 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); 381 if (err < 0) 382 return err; 383 384 if (ctrl != rx8010->ctrlreg) { 385 rx8010->ctrlreg = ctrl; 386 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, 387 rx8010->ctrlreg); 388 if (err < 0) 389 return err; 390 } 391 392 return 0; 393 } 394 395 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 396 { 397 struct i2c_client *client = to_i2c_client(dev); 398 struct rx8010_data *rx8010 = dev_get_drvdata(dev); 399 int ret, tmp; 400 int flagreg; 401 402 switch (cmd) { 403 case RTC_VL_READ: 404 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 405 if (flagreg < 0) 406 return flagreg; 407 408 tmp = !!(flagreg & RX8010_FLAG_VLF); 409 if (copy_to_user((void __user *)arg, &tmp, sizeof(int))) 410 return -EFAULT; 411 412 return 0; 413 414 case RTC_VL_CLR: 415 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); 416 if (flagreg < 0) { 417 return flagreg; 418 } 419 420 flagreg &= ~RX8010_FLAG_VLF; 421 ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); 422 if (ret < 0) 423 return ret; 424 425 return 0; 426 427 default: 428 return -ENOIOCTLCMD; 429 } 430 } 431 432 static struct rtc_class_ops rx8010_rtc_ops = { 433 .read_time = rx8010_get_time, 434 .set_time = rx8010_set_time, 435 .ioctl = rx8010_ioctl, 436 }; 437 438 static int rx8010_probe(struct i2c_client *client, 439 const struct i2c_device_id *id) 440 { 441 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 442 struct rx8010_data *rx8010; 443 int err = 0; 444 445 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 446 | I2C_FUNC_SMBUS_I2C_BLOCK)) { 447 dev_err(&adapter->dev, "doesn't support required functionality\n"); 448 return -EIO; 449 } 450 451 rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data), 452 GFP_KERNEL); 453 if (!rx8010) 454 return -ENOMEM; 455 456 rx8010->client = client; 457 i2c_set_clientdata(client, rx8010); 458 459 err = rx8010_init_client(client); 460 if (err) 461 return err; 462 463 if (client->irq > 0) { 464 dev_info(&client->dev, "IRQ %d supplied\n", client->irq); 465 err = devm_request_threaded_irq(&client->dev, client->irq, NULL, 466 rx8010_irq_1_handler, 467 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 468 "rx8010", client); 469 470 if (err) { 471 dev_err(&client->dev, "unable to request IRQ\n"); 472 client->irq = 0; 473 } else { 474 rx8010_rtc_ops.read_alarm = rx8010_read_alarm; 475 rx8010_rtc_ops.set_alarm = rx8010_set_alarm; 476 rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable; 477 } 478 } 479 480 rx8010->rtc = devm_rtc_device_register(&client->dev, client->name, 481 &rx8010_rtc_ops, THIS_MODULE); 482 483 if (IS_ERR(rx8010->rtc)) { 484 dev_err(&client->dev, "unable to register the class device\n"); 485 return PTR_ERR(rx8010->rtc); 486 } 487 488 rx8010->rtc->max_user_freq = 1; 489 490 return err; 491 } 492 493 static struct i2c_driver rx8010_driver = { 494 .driver = { 495 .name = "rtc-rx8010", 496 .of_match_table = of_match_ptr(rx8010_of_match), 497 }, 498 .probe = rx8010_probe, 499 .id_table = rx8010_id, 500 }; 501 502 module_i2c_driver(rx8010_driver); 503 504 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>"); 505 MODULE_DESCRIPTION("Epson RX8010SJ RTC driver"); 506 MODULE_LICENSE("GPL v2"); 507