1 /* 2 * An I2C driver for the Philips PCF8563 RTC 3 * Copyright 2005-06 Tower Technologies 4 * 5 * Author: Alessandro Zummo <a.zummo@towertech.it> 6 * Maintainers: http://www.nslu2-linux.org/ 7 * 8 * based on the other drivers in this same directory. 9 * 10 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License version 2 as 14 * published by the Free Software Foundation. 15 */ 16 17 #include <linux/i2c.h> 18 #include <linux/bcd.h> 19 #include <linux/rtc.h> 20 #include <linux/slab.h> 21 #include <linux/module.h> 22 #include <linux/of.h> 23 #include <linux/err.h> 24 25 #define DRV_VERSION "0.4.3" 26 27 #define PCF8563_REG_ST1 0x00 /* status */ 28 #define PCF8563_REG_ST2 0x01 29 #define PCF8563_BIT_AIE (1 << 1) 30 #define PCF8563_BIT_AF (1 << 3) 31 #define PCF8563_BITS_ST2_N (7 << 5) 32 33 #define PCF8563_REG_SC 0x02 /* datetime */ 34 #define PCF8563_REG_MN 0x03 35 #define PCF8563_REG_HR 0x04 36 #define PCF8563_REG_DM 0x05 37 #define PCF8563_REG_DW 0x06 38 #define PCF8563_REG_MO 0x07 39 #define PCF8563_REG_YR 0x08 40 41 #define PCF8563_REG_AMN 0x09 /* alarm */ 42 43 #define PCF8563_REG_CLKO 0x0D /* clock out */ 44 #define PCF8563_REG_TMRC 0x0E /* timer control */ 45 #define PCF8563_TMRC_ENABLE BIT(7) 46 #define PCF8563_TMRC_4096 0 47 #define PCF8563_TMRC_64 1 48 #define PCF8563_TMRC_1 2 49 #define PCF8563_TMRC_1_60 3 50 #define PCF8563_TMRC_MASK 3 51 52 #define PCF8563_REG_TMR 0x0F /* timer */ 53 54 #define PCF8563_SC_LV 0x80 /* low voltage */ 55 #define PCF8563_MO_C 0x80 /* century */ 56 57 static struct i2c_driver pcf8563_driver; 58 59 struct pcf8563 { 60 struct rtc_device *rtc; 61 /* 62 * The meaning of MO_C bit varies by the chip type. 63 * From PCF8563 datasheet: this bit is toggled when the years 64 * register overflows from 99 to 00 65 * 0 indicates the century is 20xx 66 * 1 indicates the century is 19xx 67 * From RTC8564 datasheet: this bit indicates change of 68 * century. When the year digit data overflows from 99 to 00, 69 * this bit is set. By presetting it to 0 while still in the 70 * 20th century, it will be set in year 2000, ... 71 * There seems no reliable way to know how the system use this 72 * bit. So let's do it heuristically, assuming we are live in 73 * 1970...2069. 74 */ 75 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ 76 int voltage_low; /* incicates if a low_voltage was detected */ 77 78 struct i2c_client *client; 79 }; 80 81 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg, 82 unsigned char length, unsigned char *buf) 83 { 84 struct i2c_msg msgs[] = { 85 {/* setup read ptr */ 86 .addr = client->addr, 87 .len = 1, 88 .buf = ®, 89 }, 90 { 91 .addr = client->addr, 92 .flags = I2C_M_RD, 93 .len = length, 94 .buf = buf 95 }, 96 }; 97 98 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { 99 dev_err(&client->dev, "%s: read error\n", __func__); 100 return -EIO; 101 } 102 103 return 0; 104 } 105 106 static int pcf8563_write_block_data(struct i2c_client *client, 107 unsigned char reg, unsigned char length, 108 unsigned char *buf) 109 { 110 int i, err; 111 112 for (i = 0; i < length; i++) { 113 unsigned char data[2] = { reg + i, buf[i] }; 114 115 err = i2c_master_send(client, data, sizeof(data)); 116 if (err != sizeof(data)) { 117 dev_err(&client->dev, 118 "%s: err=%d addr=%02x, data=%02x\n", 119 __func__, err, data[0], data[1]); 120 return -EIO; 121 } 122 } 123 124 return 0; 125 } 126 127 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on) 128 { 129 unsigned char buf; 130 int err; 131 132 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf); 133 if (err < 0) 134 return err; 135 136 if (on) 137 buf |= PCF8563_BIT_AIE; 138 else 139 buf &= ~PCF8563_BIT_AIE; 140 141 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N); 142 143 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf); 144 if (err < 0) { 145 dev_err(&client->dev, "%s: write error\n", __func__); 146 return -EIO; 147 } 148 149 return 0; 150 } 151 152 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en, 153 unsigned char *pen) 154 { 155 unsigned char buf; 156 int err; 157 158 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf); 159 if (err) 160 return err; 161 162 if (en) 163 *en = !!(buf & PCF8563_BIT_AIE); 164 if (pen) 165 *pen = !!(buf & PCF8563_BIT_AF); 166 167 return 0; 168 } 169 170 static irqreturn_t pcf8563_irq(int irq, void *dev_id) 171 { 172 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id); 173 int err; 174 char pending; 175 176 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending); 177 if (err) 178 return IRQ_NONE; 179 180 if (pending) { 181 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF); 182 pcf8563_set_alarm_mode(pcf8563->client, 1); 183 return IRQ_HANDLED; 184 } 185 186 return IRQ_NONE; 187 } 188 189 /* 190 * In the routines that deal directly with the pcf8563 hardware, we use 191 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. 192 */ 193 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) 194 { 195 struct pcf8563 *pcf8563 = i2c_get_clientdata(client); 196 unsigned char buf[9]; 197 int err; 198 199 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf); 200 if (err) 201 return err; 202 203 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { 204 pcf8563->voltage_low = 1; 205 dev_info(&client->dev, 206 "low voltage detected, date/time is not reliable.\n"); 207 } 208 209 dev_dbg(&client->dev, 210 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " 211 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", 212 __func__, 213 buf[0], buf[1], buf[2], buf[3], 214 buf[4], buf[5], buf[6], buf[7], 215 buf[8]); 216 217 218 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F); 219 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F); 220 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ 221 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F); 222 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; 223 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ 224 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]); 225 if (tm->tm_year < 70) 226 tm->tm_year += 100; /* assume we are in 1970...2069 */ 227 /* detect the polarity heuristically. see note above. */ 228 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? 229 (tm->tm_year >= 100) : (tm->tm_year < 100); 230 231 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 232 "mday=%d, mon=%d, year=%d, wday=%d\n", 233 __func__, 234 tm->tm_sec, tm->tm_min, tm->tm_hour, 235 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 236 237 /* the clock can give out invalid datetime, but we cannot return 238 * -EINVAL otherwise hwclock will refuse to set the time on bootup. 239 */ 240 if (rtc_valid_tm(tm) < 0) 241 dev_err(&client->dev, "retrieved date/time is not valid.\n"); 242 243 return 0; 244 } 245 246 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) 247 { 248 struct pcf8563 *pcf8563 = i2c_get_clientdata(client); 249 unsigned char buf[9]; 250 251 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " 252 "mday=%d, mon=%d, year=%d, wday=%d\n", 253 __func__, 254 tm->tm_sec, tm->tm_min, tm->tm_hour, 255 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 256 257 /* hours, minutes and seconds */ 258 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec); 259 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min); 260 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour); 261 262 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday); 263 264 /* month, 1 - 12 */ 265 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1); 266 267 /* year and century */ 268 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100); 269 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) 270 buf[PCF8563_REG_MO] |= PCF8563_MO_C; 271 272 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; 273 274 return pcf8563_write_block_data(client, PCF8563_REG_SC, 275 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC); 276 } 277 278 #ifdef CONFIG_RTC_INTF_DEV 279 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 280 { 281 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev)); 282 struct rtc_time tm; 283 284 switch (cmd) { 285 case RTC_VL_READ: 286 if (pcf8563->voltage_low) 287 dev_info(dev, "low voltage detected, date/time is not reliable.\n"); 288 289 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low, 290 sizeof(int))) 291 return -EFAULT; 292 return 0; 293 case RTC_VL_CLR: 294 /* 295 * Clear the VL bit in the seconds register in case 296 * the time has not been set already (which would 297 * have cleared it). This does not really matter 298 * because of the cached voltage_low value but do it 299 * anyway for consistency. 300 */ 301 if (pcf8563_get_datetime(to_i2c_client(dev), &tm)) 302 pcf8563_set_datetime(to_i2c_client(dev), &tm); 303 304 /* Clear the cached value. */ 305 pcf8563->voltage_low = 0; 306 307 return 0; 308 default: 309 return -ENOIOCTLCMD; 310 } 311 } 312 #else 313 #define pcf8563_rtc_ioctl NULL 314 #endif 315 316 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) 317 { 318 return pcf8563_get_datetime(to_i2c_client(dev), tm); 319 } 320 321 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) 322 { 323 return pcf8563_set_datetime(to_i2c_client(dev), tm); 324 } 325 326 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm) 327 { 328 struct i2c_client *client = to_i2c_client(dev); 329 unsigned char buf[4]; 330 int err; 331 332 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf); 333 if (err) 334 return err; 335 336 dev_dbg(&client->dev, 337 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n", 338 __func__, buf[0], buf[1], buf[2], buf[3]); 339 340 tm->time.tm_min = bcd2bin(buf[0] & 0x7F); 341 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F); 342 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F); 343 tm->time.tm_wday = bcd2bin(buf[3] & 0x7); 344 tm->time.tm_mon = -1; 345 tm->time.tm_year = -1; 346 tm->time.tm_yday = -1; 347 tm->time.tm_isdst = -1; 348 349 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending); 350 if (err < 0) 351 return err; 352 353 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d," 354 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min, 355 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday, 356 tm->enabled, tm->pending); 357 358 return 0; 359 } 360 361 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm) 362 { 363 struct i2c_client *client = to_i2c_client(dev); 364 unsigned char buf[4]; 365 int err; 366 unsigned long alarm_time; 367 368 /* The alarm has no seconds, round up to nearest minute */ 369 if (tm->time.tm_sec) { 370 rtc_tm_to_time(&tm->time, &alarm_time); 371 alarm_time += 60-tm->time.tm_sec; 372 rtc_time_to_tm(alarm_time, &tm->time); 373 } 374 375 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d " 376 "enabled=%d pending=%d\n", __func__, 377 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday, 378 tm->time.tm_mday, tm->enabled, tm->pending); 379 380 buf[0] = bin2bcd(tm->time.tm_min); 381 buf[1] = bin2bcd(tm->time.tm_hour); 382 buf[2] = bin2bcd(tm->time.tm_mday); 383 buf[3] = tm->time.tm_wday & 0x07; 384 385 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf); 386 if (err) 387 return err; 388 389 return pcf8563_set_alarm_mode(client, 1); 390 } 391 392 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled) 393 { 394 dev_dbg(dev, "%s: en=%d\n", __func__, enabled); 395 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled); 396 } 397 398 static const struct rtc_class_ops pcf8563_rtc_ops = { 399 .ioctl = pcf8563_rtc_ioctl, 400 .read_time = pcf8563_rtc_read_time, 401 .set_time = pcf8563_rtc_set_time, 402 .read_alarm = pcf8563_rtc_read_alarm, 403 .set_alarm = pcf8563_rtc_set_alarm, 404 .alarm_irq_enable = pcf8563_irq_enable, 405 }; 406 407 static int pcf8563_probe(struct i2c_client *client, 408 const struct i2c_device_id *id) 409 { 410 struct pcf8563 *pcf8563; 411 int err; 412 unsigned char buf; 413 unsigned char alm_pending; 414 415 dev_dbg(&client->dev, "%s\n", __func__); 416 417 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 418 return -ENODEV; 419 420 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563), 421 GFP_KERNEL); 422 if (!pcf8563) 423 return -ENOMEM; 424 425 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); 426 427 i2c_set_clientdata(client, pcf8563); 428 pcf8563->client = client; 429 device_set_wakeup_capable(&client->dev, 1); 430 431 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ 432 buf = PCF8563_TMRC_1_60; 433 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf); 434 if (err < 0) { 435 dev_err(&client->dev, "%s: write error\n", __func__); 436 return err; 437 } 438 439 err = pcf8563_get_alarm_mode(client, NULL, &alm_pending); 440 if (err < 0) { 441 dev_err(&client->dev, "%s: read error\n", __func__); 442 return err; 443 } 444 if (alm_pending) 445 pcf8563_set_alarm_mode(client, 0); 446 447 pcf8563->rtc = devm_rtc_device_register(&client->dev, 448 pcf8563_driver.driver.name, 449 &pcf8563_rtc_ops, THIS_MODULE); 450 451 if (IS_ERR(pcf8563->rtc)) 452 return PTR_ERR(pcf8563->rtc); 453 454 if (client->irq > 0) { 455 err = devm_request_threaded_irq(&client->dev, client->irq, 456 NULL, pcf8563_irq, 457 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING, 458 pcf8563->rtc->name, client); 459 if (err) { 460 dev_err(&client->dev, "unable to request IRQ %d\n", 461 client->irq); 462 return err; 463 } 464 465 } 466 467 /* the pcf8563 alarm only supports a minute accuracy */ 468 pcf8563->rtc->uie_unsupported = 1; 469 470 return 0; 471 } 472 473 static const struct i2c_device_id pcf8563_id[] = { 474 { "pcf8563", 0 }, 475 { "rtc8564", 0 }, 476 { } 477 }; 478 MODULE_DEVICE_TABLE(i2c, pcf8563_id); 479 480 #ifdef CONFIG_OF 481 static const struct of_device_id pcf8563_of_match[] = { 482 { .compatible = "nxp,pcf8563" }, 483 {} 484 }; 485 MODULE_DEVICE_TABLE(of, pcf8563_of_match); 486 #endif 487 488 static struct i2c_driver pcf8563_driver = { 489 .driver = { 490 .name = "rtc-pcf8563", 491 .owner = THIS_MODULE, 492 .of_match_table = of_match_ptr(pcf8563_of_match), 493 }, 494 .probe = pcf8563_probe, 495 .id_table = pcf8563_id, 496 }; 497 498 module_i2c_driver(pcf8563_driver); 499 500 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 501 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); 502 MODULE_LICENSE("GPL"); 503 MODULE_VERSION(DRV_VERSION); 504