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