1 /* 2 * RTC driver for the Micro Crystal RV8803 3 * 4 * Copyright (C) 2015 Micro Crystal SA 5 * 6 * Alexandre Belloni <alexandre.belloni@free-electrons.com> 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 */ 13 14 #include <linux/bcd.h> 15 #include <linux/bitops.h> 16 #include <linux/i2c.h> 17 #include <linux/interrupt.h> 18 #include <linux/kernel.h> 19 #include <linux/module.h> 20 #include <linux/rtc.h> 21 22 #define RV8803_SEC 0x00 23 #define RV8803_MIN 0x01 24 #define RV8803_HOUR 0x02 25 #define RV8803_WEEK 0x03 26 #define RV8803_DAY 0x04 27 #define RV8803_MONTH 0x05 28 #define RV8803_YEAR 0x06 29 #define RV8803_RAM 0x07 30 #define RV8803_ALARM_MIN 0x08 31 #define RV8803_ALARM_HOUR 0x09 32 #define RV8803_ALARM_WEEK_OR_DAY 0x0A 33 #define RV8803_EXT 0x0D 34 #define RV8803_FLAG 0x0E 35 #define RV8803_CTRL 0x0F 36 37 #define RV8803_EXT_WADA BIT(6) 38 39 #define RV8803_FLAG_V1F BIT(0) 40 #define RV8803_FLAG_V2F BIT(1) 41 #define RV8803_FLAG_AF BIT(3) 42 #define RV8803_FLAG_TF BIT(4) 43 #define RV8803_FLAG_UF BIT(5) 44 45 #define RV8803_CTRL_RESET BIT(0) 46 47 #define RV8803_CTRL_EIE BIT(2) 48 #define RV8803_CTRL_AIE BIT(3) 49 #define RV8803_CTRL_TIE BIT(4) 50 #define RV8803_CTRL_UIE BIT(5) 51 52 struct rv8803_data { 53 struct i2c_client *client; 54 struct rtc_device *rtc; 55 spinlock_t flags_lock; 56 u8 ctrl; 57 }; 58 59 static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) 60 { 61 struct i2c_client *client = dev_id; 62 struct rv8803_data *rv8803 = i2c_get_clientdata(client); 63 unsigned long events = 0; 64 int flags; 65 66 spin_lock(&rv8803->flags_lock); 67 68 flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); 69 if (flags <= 0) { 70 spin_unlock(&rv8803->flags_lock); 71 return IRQ_NONE; 72 } 73 74 if (flags & RV8803_FLAG_V1F) 75 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); 76 77 if (flags & RV8803_FLAG_V2F) 78 dev_warn(&client->dev, "Voltage low, data loss detected.\n"); 79 80 if (flags & RV8803_FLAG_TF) { 81 flags &= ~RV8803_FLAG_TF; 82 rv8803->ctrl &= ~RV8803_CTRL_TIE; 83 events |= RTC_PF; 84 } 85 86 if (flags & RV8803_FLAG_AF) { 87 flags &= ~RV8803_FLAG_AF; 88 rv8803->ctrl &= ~RV8803_CTRL_AIE; 89 events |= RTC_AF; 90 } 91 92 if (flags & RV8803_FLAG_UF) { 93 flags &= ~RV8803_FLAG_UF; 94 rv8803->ctrl &= ~RV8803_CTRL_UIE; 95 events |= RTC_UF; 96 } 97 98 if (events) { 99 rtc_update_irq(rv8803->rtc, 1, events); 100 i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); 101 i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, 102 rv8803->ctrl); 103 } 104 105 spin_unlock(&rv8803->flags_lock); 106 107 return IRQ_HANDLED; 108 } 109 110 static int rv8803_get_time(struct device *dev, struct rtc_time *tm) 111 { 112 struct rv8803_data *rv8803 = dev_get_drvdata(dev); 113 u8 date1[7]; 114 u8 date2[7]; 115 u8 *date = date1; 116 int ret, flags; 117 118 flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG); 119 if (flags < 0) 120 return flags; 121 122 if (flags & RV8803_FLAG_V2F) { 123 dev_warn(dev, "Voltage low, data is invalid.\n"); 124 return -EINVAL; 125 } 126 127 ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC, 128 7, date); 129 if (ret != 7) 130 return ret < 0 ? ret : -EIO; 131 132 if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) { 133 ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC, 134 7, date2); 135 if (ret != 7) 136 return ret < 0 ? ret : -EIO; 137 138 if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59)) 139 date = date2; 140 } 141 142 tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f); 143 tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f); 144 tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f); 145 tm->tm_wday = ffs(date[RV8803_WEEK] & 0x7f); 146 tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f); 147 tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1; 148 tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100; 149 150 return rtc_valid_tm(tm); 151 } 152 153 static int rv8803_set_time(struct device *dev, struct rtc_time *tm) 154 { 155 struct rv8803_data *rv8803 = dev_get_drvdata(dev); 156 u8 date[7]; 157 int flags, ret; 158 unsigned long irqflags; 159 160 if ((tm->tm_year < 100) || (tm->tm_year > 199)) 161 return -EINVAL; 162 163 date[RV8803_SEC] = bin2bcd(tm->tm_sec); 164 date[RV8803_MIN] = bin2bcd(tm->tm_min); 165 date[RV8803_HOUR] = bin2bcd(tm->tm_hour); 166 date[RV8803_WEEK] = 1 << (tm->tm_wday); 167 date[RV8803_DAY] = bin2bcd(tm->tm_mday); 168 date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1); 169 date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100); 170 171 ret = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC, 172 7, date); 173 if (ret < 0) 174 return ret; 175 176 spin_lock_irqsave(&rv8803->flags_lock, irqflags); 177 178 flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG); 179 if (flags < 0) { 180 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 181 return flags; 182 } 183 184 ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, 185 flags & ~RV8803_FLAG_V2F); 186 187 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 188 189 return ret; 190 } 191 192 static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) 193 { 194 struct rv8803_data *rv8803 = dev_get_drvdata(dev); 195 struct i2c_client *client = rv8803->client; 196 u8 alarmvals[3]; 197 int flags, ret; 198 199 ret = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN, 200 3, alarmvals); 201 if (ret != 3) 202 return ret < 0 ? ret : -EIO; 203 204 flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); 205 if (flags < 0) 206 return flags; 207 208 alrm->time.tm_sec = 0; 209 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); 210 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); 211 alrm->time.tm_wday = -1; 212 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f); 213 alrm->time.tm_mon = -1; 214 alrm->time.tm_year = -1; 215 216 alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE); 217 alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled; 218 219 return 0; 220 } 221 222 static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 223 { 224 struct i2c_client *client = to_i2c_client(dev); 225 struct rv8803_data *rv8803 = dev_get_drvdata(dev); 226 u8 alarmvals[3]; 227 u8 ctrl[2]; 228 int ret, err; 229 unsigned long irqflags; 230 231 /* The alarm has no seconds, round up to nearest minute */ 232 if (alrm->time.tm_sec) { 233 time64_t alarm_time = rtc_tm_to_time64(&alrm->time); 234 235 alarm_time += 60 - alrm->time.tm_sec; 236 rtc_time64_to_tm(alarm_time, &alrm->time); 237 } 238 239 spin_lock_irqsave(&rv8803->flags_lock, irqflags); 240 241 ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl); 242 if (ret != 2) { 243 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 244 return ret < 0 ? ret : -EIO; 245 } 246 247 alarmvals[0] = bin2bcd(alrm->time.tm_min); 248 alarmvals[1] = bin2bcd(alrm->time.tm_hour); 249 alarmvals[2] = bin2bcd(alrm->time.tm_mday); 250 251 if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) { 252 rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE); 253 err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, 254 rv8803->ctrl); 255 if (err) { 256 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 257 return err; 258 } 259 } 260 261 ctrl[1] &= ~RV8803_FLAG_AF; 262 err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]); 263 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 264 if (err) 265 return err; 266 267 err = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_ALARM_MIN, 268 3, alarmvals); 269 if (err) 270 return err; 271 272 if (alrm->enabled) { 273 if (rv8803->rtc->uie_rtctimer.enabled) 274 rv8803->ctrl |= RV8803_CTRL_UIE; 275 if (rv8803->rtc->aie_timer.enabled) 276 rv8803->ctrl |= RV8803_CTRL_AIE; 277 278 err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, 279 rv8803->ctrl); 280 if (err) 281 return err; 282 } 283 284 return 0; 285 } 286 287 static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled) 288 { 289 struct i2c_client *client = to_i2c_client(dev); 290 struct rv8803_data *rv8803 = dev_get_drvdata(dev); 291 int ctrl, flags, err; 292 unsigned long irqflags; 293 294 ctrl = rv8803->ctrl; 295 296 if (enabled) { 297 if (rv8803->rtc->uie_rtctimer.enabled) 298 ctrl |= RV8803_CTRL_UIE; 299 if (rv8803->rtc->aie_timer.enabled) 300 ctrl |= RV8803_CTRL_AIE; 301 } else { 302 if (!rv8803->rtc->uie_rtctimer.enabled) 303 ctrl &= ~RV8803_CTRL_UIE; 304 if (!rv8803->rtc->aie_timer.enabled) 305 ctrl &= ~RV8803_CTRL_AIE; 306 } 307 308 spin_lock_irqsave(&rv8803->flags_lock, irqflags); 309 flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); 310 if (flags < 0) { 311 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 312 return flags; 313 } 314 flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF); 315 err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); 316 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 317 if (err) 318 return err; 319 320 if (ctrl != rv8803->ctrl) { 321 rv8803->ctrl = ctrl; 322 err = i2c_smbus_write_byte_data(client, RV8803_CTRL, 323 rv8803->ctrl); 324 if (err) 325 return err; 326 } 327 328 return 0; 329 } 330 331 static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 332 { 333 struct i2c_client *client = to_i2c_client(dev); 334 struct rv8803_data *rv8803 = dev_get_drvdata(dev); 335 int flags, ret = 0; 336 unsigned long irqflags; 337 338 switch (cmd) { 339 case RTC_VL_READ: 340 flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); 341 if (flags < 0) 342 return flags; 343 344 if (flags & RV8803_FLAG_V1F) 345 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); 346 347 if (flags & RV8803_FLAG_V2F) 348 dev_warn(&client->dev, "Voltage low, data loss detected.\n"); 349 350 flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F; 351 352 if (copy_to_user((void __user *)arg, &flags, sizeof(int))) 353 return -EFAULT; 354 355 return 0; 356 357 case RTC_VL_CLR: 358 spin_lock_irqsave(&rv8803->flags_lock, irqflags); 359 flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); 360 if (flags < 0) { 361 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 362 return flags; 363 } 364 365 flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F); 366 ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); 367 spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); 368 if (ret < 0) 369 return ret; 370 371 return 0; 372 373 default: 374 return -ENOIOCTLCMD; 375 } 376 } 377 378 static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj, 379 struct bin_attribute *attr, 380 char *buf, loff_t off, size_t count) 381 { 382 struct device *dev = kobj_to_dev(kobj); 383 struct i2c_client *client = to_i2c_client(dev); 384 int ret; 385 386 ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]); 387 if (ret < 0) 388 return ret; 389 390 return 1; 391 } 392 393 static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj, 394 struct bin_attribute *attr, 395 char *buf, loff_t off, size_t count) 396 { 397 struct device *dev = kobj_to_dev(kobj); 398 struct i2c_client *client = to_i2c_client(dev); 399 int ret; 400 401 ret = i2c_smbus_read_byte_data(client, RV8803_RAM); 402 if (ret < 0) 403 return ret; 404 405 buf[0] = ret; 406 407 return 1; 408 } 409 410 static struct bin_attribute rv8803_nvram_attr = { 411 .attr = { 412 .name = "nvram", 413 .mode = S_IRUGO | S_IWUSR, 414 }, 415 .size = 1, 416 .read = rv8803_nvram_read, 417 .write = rv8803_nvram_write, 418 }; 419 420 static struct rtc_class_ops rv8803_rtc_ops = { 421 .read_time = rv8803_get_time, 422 .set_time = rv8803_set_time, 423 .ioctl = rv8803_ioctl, 424 }; 425 426 static int rv8803_probe(struct i2c_client *client, 427 const struct i2c_device_id *id) 428 { 429 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 430 struct rv8803_data *rv8803; 431 int err, flags; 432 433 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 434 I2C_FUNC_SMBUS_I2C_BLOCK)) { 435 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n"); 436 return -EIO; 437 } 438 439 rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data), 440 GFP_KERNEL); 441 if (!rv8803) 442 return -ENOMEM; 443 444 rv8803->client = client; 445 i2c_set_clientdata(client, rv8803); 446 447 flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); 448 if (flags < 0) 449 return flags; 450 451 if (flags & RV8803_FLAG_V1F) 452 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); 453 454 if (flags & RV8803_FLAG_V2F) 455 dev_warn(&client->dev, "Voltage low, data loss detected.\n"); 456 457 if (flags & RV8803_FLAG_AF) 458 dev_warn(&client->dev, "An alarm maybe have been missed.\n"); 459 460 if (client->irq > 0) { 461 err = devm_request_threaded_irq(&client->dev, client->irq, 462 NULL, rv8803_handle_irq, 463 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 464 "rv8803", client); 465 if (err) { 466 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); 467 client->irq = 0; 468 } else { 469 rv8803_rtc_ops.read_alarm = rv8803_get_alarm; 470 rv8803_rtc_ops.set_alarm = rv8803_set_alarm; 471 rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable; 472 } 473 } 474 475 rv8803->rtc = devm_rtc_device_register(&client->dev, client->name, 476 &rv8803_rtc_ops, THIS_MODULE); 477 if (IS_ERR(rv8803->rtc)) { 478 dev_err(&client->dev, "unable to register the class device\n"); 479 return PTR_ERR(rv8803->rtc); 480 } 481 482 err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT, 483 RV8803_EXT_WADA); 484 if (err) 485 return err; 486 487 err = device_create_bin_file(&client->dev, &rv8803_nvram_attr); 488 if (err) 489 return err; 490 491 rv8803->rtc->max_user_freq = 1; 492 493 return 0; 494 } 495 496 static int rv8803_remove(struct i2c_client *client) 497 { 498 device_remove_bin_file(&client->dev, &rv8803_nvram_attr); 499 500 return 0; 501 } 502 503 static const struct i2c_device_id rv8803_id[] = { 504 { "rv8803", 0 }, 505 { "rx8900", 0 }, 506 { } 507 }; 508 MODULE_DEVICE_TABLE(i2c, rv8803_id); 509 510 static struct i2c_driver rv8803_driver = { 511 .driver = { 512 .name = "rtc-rv8803", 513 }, 514 .probe = rv8803_probe, 515 .remove = rv8803_remove, 516 .id_table = rv8803_id, 517 }; 518 module_i2c_driver(rv8803_driver); 519 520 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>"); 521 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver"); 522 MODULE_LICENSE("GPL v2"); 523