2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
4 * Copyright (C) 2005 James Chapman (ds1337 core)
5 * Copyright (C) 2006 David Brownell
6 * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
7 * Copyright (C) 2012 Bertrand Achard (nvram access fixes)
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/bcd.h>
15 #include <linux/i2c.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/rtc/ds1307.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
24 * We can't determine type by probing, but if we expect pre-Linux code
25 * to have set the chip up as a clock (turning on the oscillator and
26 * setting the date and time), Linux can ignore the non-clock features.
27 * That's a natural job for a factory or repair bench.
40 last_ds_type /* always last */
41 /* rs5c372 too? different address... */
45 /* RTC registers don't differ much, except for the century flag */
46 #define DS1307_REG_SECS 0x00 /* 00-59 */
47 # define DS1307_BIT_CH 0x80
48 # define DS1340_BIT_nEOSC 0x80
49 # define MCP794XX_BIT_ST 0x80
50 #define DS1307_REG_MIN 0x01 /* 00-59 */
51 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
52 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
53 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
54 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
55 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
56 #define DS1307_REG_WDAY 0x03 /* 01-07 */
57 # define MCP794XX_BIT_VBATEN 0x08
58 #define DS1307_REG_MDAY 0x04 /* 01-31 */
59 #define DS1307_REG_MONTH 0x05 /* 01-12 */
60 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
61 #define DS1307_REG_YEAR 0x06 /* 00-99 */
64 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
65 * start at 7, and they differ a LOT. Only control and status matter for
66 * basic RTC date and time functionality; be careful using them.
68 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
69 # define DS1307_BIT_OUT 0x80
70 # define DS1338_BIT_OSF 0x20
71 # define DS1307_BIT_SQWE 0x10
72 # define DS1307_BIT_RS1 0x02
73 # define DS1307_BIT_RS0 0x01
74 #define DS1337_REG_CONTROL 0x0e
75 # define DS1337_BIT_nEOSC 0x80
76 # define DS1339_BIT_BBSQI 0x20
77 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
78 # define DS1337_BIT_RS2 0x10
79 # define DS1337_BIT_RS1 0x08
80 # define DS1337_BIT_INTCN 0x04
81 # define DS1337_BIT_A2IE 0x02
82 # define DS1337_BIT_A1IE 0x01
83 #define DS1340_REG_CONTROL 0x07
84 # define DS1340_BIT_OUT 0x80
85 # define DS1340_BIT_FT 0x40
86 # define DS1340_BIT_CALIB_SIGN 0x20
87 # define DS1340_M_CALIBRATION 0x1f
88 #define DS1340_REG_FLAG 0x09
89 # define DS1340_BIT_OSF 0x80
90 #define DS1337_REG_STATUS 0x0f
91 # define DS1337_BIT_OSF 0x80
92 # define DS1337_BIT_A2I 0x02
93 # define DS1337_BIT_A1I 0x01
94 #define DS1339_REG_ALARM1_SECS 0x07
96 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
98 #define RX8025_REG_CTRL1 0x0e
99 # define RX8025_BIT_2412 0x20
100 #define RX8025_REG_CTRL2 0x0f
101 # define RX8025_BIT_PON 0x10
102 # define RX8025_BIT_VDET 0x40
103 # define RX8025_BIT_XST 0x20
107 u8 offset; /* register's offset */
110 struct bin_attribute *nvram;
113 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
114 #define HAS_ALARM 1 /* bit 1 == irq claimed */
115 struct i2c_client *client;
116 struct rtc_device *rtc;
117 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
118 u8 length, u8 *values);
119 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
120 u8 length, const u8 *values);
127 u16 trickle_charger_reg;
128 u8 trickle_charger_setup;
129 u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
132 static u8 do_trickle_setup_ds1339(struct i2c_client *,
133 uint32_t ohms, bool diode);
135 static struct chip_desc chips[last_ds_type] = {
149 .trickle_charger_reg = 0x10,
150 .do_trickle_setup = &do_trickle_setup_ds1339,
153 .trickle_charger_reg = 0x08,
156 .trickle_charger_reg = 0x0a,
163 /* this is battery backed SRAM */
164 .nvram_offset = 0x20,
169 static const struct i2c_device_id ds1307_id[] = {
170 { "ds1307", ds_1307 },
171 { "ds1337", ds_1337 },
172 { "ds1338", ds_1338 },
173 { "ds1339", ds_1339 },
174 { "ds1388", ds_1388 },
175 { "ds1340", ds_1340 },
176 { "ds3231", ds_3231 },
177 { "m41t00", m41t00 },
178 { "mcp7940x", mcp794xx },
179 { "mcp7941x", mcp794xx },
180 { "pt7c4338", ds_1307 },
181 { "rx8025", rx_8025 },
184 MODULE_DEVICE_TABLE(i2c, ds1307_id);
186 /*----------------------------------------------------------------------*/
188 #define BLOCK_DATA_MAX_TRIES 10
190 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
191 u8 command, u8 length, u8 *values)
195 for (i = 0; i < length; i++) {
196 data = i2c_smbus_read_byte_data(client, command + i);
204 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
205 u8 length, u8 *values)
211 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
212 ret = ds1307_read_block_data_once(client, command, length, values);
216 if (++tries > BLOCK_DATA_MAX_TRIES) {
217 dev_err(&client->dev,
218 "ds1307_read_block_data failed\n");
221 memcpy(oldvalues, values, length);
222 ret = ds1307_read_block_data_once(client, command, length,
226 } while (memcmp(oldvalues, values, length));
230 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
231 u8 length, const u8 *values)
236 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
240 if (++tries > BLOCK_DATA_MAX_TRIES) {
241 dev_err(&client->dev,
242 "ds1307_write_block_data failed\n");
245 for (i = 0; i < length; i++) {
246 ret = i2c_smbus_write_byte_data(client, command + i,
251 ret = ds1307_read_block_data_once(client, command, length,
255 } while (memcmp(currvalues, values, length));
259 /*----------------------------------------------------------------------*/
261 /* These RTC devices are not designed to be connected to a SMbus adapter.
262 SMbus limits block operations length to 32 bytes, whereas it's not
263 limited on I2C buses. As a result, accesses may exceed 32 bytes;
264 in that case, split them into smaller blocks */
266 static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
267 u8 command, u8 length, const u8 *values)
271 if (length <= I2C_SMBUS_BLOCK_MAX)
272 return i2c_smbus_write_i2c_block_data(client,
273 command, length, values);
275 while (suboffset < length) {
276 s32 retval = i2c_smbus_write_i2c_block_data(client,
278 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
283 suboffset += I2C_SMBUS_BLOCK_MAX;
288 static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
289 u8 command, u8 length, u8 *values)
293 if (length <= I2C_SMBUS_BLOCK_MAX)
294 return i2c_smbus_read_i2c_block_data(client,
295 command, length, values);
297 while (suboffset < length) {
298 s32 retval = i2c_smbus_read_i2c_block_data(client,
300 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
305 suboffset += I2C_SMBUS_BLOCK_MAX;
310 /*----------------------------------------------------------------------*/
313 * The ds1337 and ds1339 both have two alarms, but we only use the first
314 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
315 * signal; ds1339 chips have only one alarm signal.
317 static irqreturn_t ds1307_irq(int irq, void *dev_id)
319 struct i2c_client *client = dev_id;
320 struct ds1307 *ds1307 = i2c_get_clientdata(client);
321 struct mutex *lock = &ds1307->rtc->ops_lock;
325 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
329 if (stat & DS1337_BIT_A1I) {
330 stat &= ~DS1337_BIT_A1I;
331 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
333 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
337 control &= ~DS1337_BIT_A1IE;
338 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
340 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
349 /*----------------------------------------------------------------------*/
351 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
353 struct ds1307 *ds1307 = dev_get_drvdata(dev);
356 /* read the RTC date and time registers all at once */
357 tmp = ds1307->read_block_data(ds1307->client,
358 ds1307->offset, 7, ds1307->regs);
360 dev_err(dev, "%s error %d\n", "read", tmp);
364 dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
366 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
367 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
368 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
369 t->tm_hour = bcd2bin(tmp);
370 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
371 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
372 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
373 t->tm_mon = bcd2bin(tmp) - 1;
375 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
376 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
378 dev_dbg(dev, "%s secs=%d, mins=%d, "
379 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
380 "read", t->tm_sec, t->tm_min,
381 t->tm_hour, t->tm_mday,
382 t->tm_mon, t->tm_year, t->tm_wday);
384 /* initial clock setting can be undefined */
385 return rtc_valid_tm(t);
388 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
390 struct ds1307 *ds1307 = dev_get_drvdata(dev);
393 u8 *buf = ds1307->regs;
395 dev_dbg(dev, "%s secs=%d, mins=%d, "
396 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
397 "write", t->tm_sec, t->tm_min,
398 t->tm_hour, t->tm_mday,
399 t->tm_mon, t->tm_year, t->tm_wday);
401 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
402 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
403 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
404 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
405 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
406 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
408 /* assume 20YY not 19YY */
409 tmp = t->tm_year - 100;
410 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
412 switch (ds1307->type) {
416 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
419 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
420 | DS1340_BIT_CENTURY;
424 * these bits were cleared when preparing the date/time
425 * values and need to be set again before writing the
426 * buffer out to the device.
428 buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
429 buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
435 dev_dbg(dev, "%s: %7ph\n", "write", buf);
437 result = ds1307->write_block_data(ds1307->client,
438 ds1307->offset, 7, buf);
440 dev_err(dev, "%s error %d\n", "write", result);
446 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
448 struct i2c_client *client = to_i2c_client(dev);
449 struct ds1307 *ds1307 = i2c_get_clientdata(client);
452 if (!test_bit(HAS_ALARM, &ds1307->flags))
455 /* read all ALARM1, ALARM2, and status registers at once */
456 ret = ds1307->read_block_data(client,
457 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
459 dev_err(dev, "%s error %d\n", "alarm read", ret);
463 dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
464 &ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
467 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
468 * and that all four fields are checked matches
470 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
471 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
472 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
473 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
475 t->time.tm_year = -1;
476 t->time.tm_wday = -1;
477 t->time.tm_yday = -1;
478 t->time.tm_isdst = -1;
481 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
482 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
484 dev_dbg(dev, "%s secs=%d, mins=%d, "
485 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
486 "alarm read", t->time.tm_sec, t->time.tm_min,
487 t->time.tm_hour, t->time.tm_mday,
488 t->enabled, t->pending);
493 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
495 struct i2c_client *client = to_i2c_client(dev);
496 struct ds1307 *ds1307 = i2c_get_clientdata(client);
497 unsigned char *buf = ds1307->regs;
501 if (!test_bit(HAS_ALARM, &ds1307->flags))
504 dev_dbg(dev, "%s secs=%d, mins=%d, "
505 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
506 "alarm set", t->time.tm_sec, t->time.tm_min,
507 t->time.tm_hour, t->time.tm_mday,
508 t->enabled, t->pending);
510 /* read current status of both alarms and the chip */
511 ret = ds1307->read_block_data(client,
512 DS1339_REG_ALARM1_SECS, 9, buf);
514 dev_err(dev, "%s error %d\n", "alarm write", ret);
517 control = ds1307->regs[7];
518 status = ds1307->regs[8];
520 dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
521 &ds1307->regs[0], &ds1307->regs[4], control, status);
523 /* set ALARM1, using 24 hour and day-of-month modes */
524 buf[0] = bin2bcd(t->time.tm_sec);
525 buf[1] = bin2bcd(t->time.tm_min);
526 buf[2] = bin2bcd(t->time.tm_hour);
527 buf[3] = bin2bcd(t->time.tm_mday);
529 /* set ALARM2 to non-garbage */
534 /* optionally enable ALARM1 */
535 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
537 dev_dbg(dev, "alarm IRQ armed\n");
538 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
540 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
542 ret = ds1307->write_block_data(client,
543 DS1339_REG_ALARM1_SECS, 9, buf);
545 dev_err(dev, "can't set alarm time\n");
552 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
554 struct i2c_client *client = to_i2c_client(dev);
555 struct ds1307 *ds1307 = i2c_get_clientdata(client);
558 if (!test_bit(HAS_ALARM, &ds1307->flags))
561 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
566 ret |= DS1337_BIT_A1IE;
568 ret &= ~DS1337_BIT_A1IE;
570 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
577 static const struct rtc_class_ops ds13xx_rtc_ops = {
578 .read_time = ds1307_get_time,
579 .set_time = ds1307_set_time,
580 .read_alarm = ds1337_read_alarm,
581 .set_alarm = ds1337_set_alarm,
582 .alarm_irq_enable = ds1307_alarm_irq_enable,
585 /*----------------------------------------------------------------------*/
588 * Alarm support for mcp794xx devices.
591 #define MCP794XX_REG_CONTROL 0x07
592 # define MCP794XX_BIT_ALM0_EN 0x10
593 # define MCP794XX_BIT_ALM1_EN 0x20
594 #define MCP794XX_REG_ALARM0_BASE 0x0a
595 #define MCP794XX_REG_ALARM0_CTRL 0x0d
596 #define MCP794XX_REG_ALARM1_BASE 0x11
597 #define MCP794XX_REG_ALARM1_CTRL 0x14
598 # define MCP794XX_BIT_ALMX_IF (1 << 3)
599 # define MCP794XX_BIT_ALMX_C0 (1 << 4)
600 # define MCP794XX_BIT_ALMX_C1 (1 << 5)
601 # define MCP794XX_BIT_ALMX_C2 (1 << 6)
602 # define MCP794XX_BIT_ALMX_POL (1 << 7)
603 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
604 MCP794XX_BIT_ALMX_C1 | \
605 MCP794XX_BIT_ALMX_C2)
607 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
609 struct i2c_client *client = dev_id;
610 struct ds1307 *ds1307 = i2c_get_clientdata(client);
611 struct mutex *lock = &ds1307->rtc->ops_lock;
616 /* Check and clear alarm 0 interrupt flag. */
617 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
620 if (!(reg & MCP794XX_BIT_ALMX_IF))
622 reg &= ~MCP794XX_BIT_ALMX_IF;
623 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
627 /* Disable alarm 0. */
628 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
631 reg &= ~MCP794XX_BIT_ALM0_EN;
632 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
636 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
644 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
646 struct i2c_client *client = to_i2c_client(dev);
647 struct ds1307 *ds1307 = i2c_get_clientdata(client);
648 u8 *regs = ds1307->regs;
651 if (!test_bit(HAS_ALARM, &ds1307->flags))
654 /* Read control and alarm 0 registers. */
655 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
659 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
661 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
662 t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
663 t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
664 t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
665 t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
666 t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
667 t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
668 t->time.tm_year = -1;
669 t->time.tm_yday = -1;
670 t->time.tm_isdst = -1;
672 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
673 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
674 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
675 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
676 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
677 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
678 (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
683 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
685 struct i2c_client *client = to_i2c_client(dev);
686 struct ds1307 *ds1307 = i2c_get_clientdata(client);
687 unsigned char *regs = ds1307->regs;
690 if (!test_bit(HAS_ALARM, &ds1307->flags))
693 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
694 "enabled=%d pending=%d\n", __func__,
695 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
696 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
697 t->enabled, t->pending);
699 /* Read control and alarm 0 registers. */
700 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
704 /* Set alarm 0, using 24-hour and day-of-month modes. */
705 regs[3] = bin2bcd(t->time.tm_sec);
706 regs[4] = bin2bcd(t->time.tm_min);
707 regs[5] = bin2bcd(t->time.tm_hour);
708 regs[6] = bin2bcd(t->time.tm_wday + 1);
709 regs[7] = bin2bcd(t->time.tm_mday);
710 regs[8] = bin2bcd(t->time.tm_mon + 1);
712 /* Clear the alarm 0 interrupt flag. */
713 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
714 /* Set alarm match: second, minute, hour, day, date, month. */
715 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
716 /* Disable interrupt. We will not enable until completely programmed */
717 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
719 ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
725 regs[0] |= MCP794XX_BIT_ALM0_EN;
726 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
729 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
731 struct i2c_client *client = to_i2c_client(dev);
732 struct ds1307 *ds1307 = i2c_get_clientdata(client);
735 if (!test_bit(HAS_ALARM, &ds1307->flags))
738 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
743 reg |= MCP794XX_BIT_ALM0_EN;
745 reg &= ~MCP794XX_BIT_ALM0_EN;
747 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
750 static const struct rtc_class_ops mcp794xx_rtc_ops = {
751 .read_time = ds1307_get_time,
752 .set_time = ds1307_set_time,
753 .read_alarm = mcp794xx_read_alarm,
754 .set_alarm = mcp794xx_set_alarm,
755 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
758 /*----------------------------------------------------------------------*/
761 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
762 struct bin_attribute *attr,
763 char *buf, loff_t off, size_t count)
765 struct i2c_client *client;
766 struct ds1307 *ds1307;
769 client = kobj_to_i2c_client(kobj);
770 ds1307 = i2c_get_clientdata(client);
772 result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
775 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
780 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
781 struct bin_attribute *attr,
782 char *buf, loff_t off, size_t count)
784 struct i2c_client *client;
785 struct ds1307 *ds1307;
788 client = kobj_to_i2c_client(kobj);
789 ds1307 = i2c_get_clientdata(client);
791 result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
794 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
801 /*----------------------------------------------------------------------*/
803 static u8 do_trickle_setup_ds1339(struct i2c_client *client,
804 uint32_t ohms, bool diode)
806 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
807 DS1307_TRICKLE_CHARGER_NO_DIODE;
811 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
814 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
817 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
820 dev_warn(&client->dev,
821 "Unsupported ohm value %u in dt\n", ohms);
827 static void ds1307_trickle_of_init(struct i2c_client *client,
828 struct chip_desc *chip)
833 if (!chip->do_trickle_setup)
835 if (of_property_read_u32(client->dev.of_node, "trickle-resistor-ohms" , &ohms))
837 if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
839 chip->trickle_charger_setup = chip->do_trickle_setup(client,
845 static int ds1307_probe(struct i2c_client *client,
846 const struct i2c_device_id *id)
848 struct ds1307 *ds1307;
851 struct chip_desc *chip = &chips[id->driver_data];
852 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
853 bool want_irq = false;
855 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
856 irq_handler_t irq_handler = ds1307_irq;
858 static const int bbsqi_bitpos[] = {
860 [ds_1339] = DS1339_BIT_BBSQI,
861 [ds_3231] = DS3231_BIT_BBSQW,
863 const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
865 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
866 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
869 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
873 i2c_set_clientdata(client, ds1307);
875 ds1307->client = client;
876 ds1307->type = id->driver_data;
878 if (!pdata && client->dev.of_node)
879 ds1307_trickle_of_init(client, chip);
880 else if (pdata && pdata->trickle_charger_setup)
881 chip->trickle_charger_setup = pdata->trickle_charger_setup;
883 if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
884 dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
885 DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
886 chip->trickle_charger_reg);
887 i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
888 DS13XX_TRICKLE_CHARGER_MAGIC |
889 chip->trickle_charger_setup);
893 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
894 ds1307->read_block_data = ds1307_native_smbus_read_block_data;
895 ds1307->write_block_data = ds1307_native_smbus_write_block_data;
897 ds1307->read_block_data = ds1307_read_block_data;
898 ds1307->write_block_data = ds1307_write_block_data;
901 switch (ds1307->type) {
905 /* get registers that the "rtc" read below won't read... */
906 tmp = ds1307->read_block_data(ds1307->client,
907 DS1337_REG_CONTROL, 2, buf);
909 dev_dbg(&client->dev, "read error %d\n", tmp);
914 /* oscillator off? turn it on, so clock can tick. */
915 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
916 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
919 * Using IRQ? Disable the square wave and both alarms.
920 * For some variants, be sure alarms can trigger when we're
921 * running on Vbackup (BBSQI/BBSQW)
923 if (ds1307->client->irq > 0 && chip->alarm) {
924 ds1307->regs[0] |= DS1337_BIT_INTCN
925 | bbsqi_bitpos[ds1307->type];
926 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
931 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
934 /* oscillator fault? clear flag, and warn */
935 if (ds1307->regs[1] & DS1337_BIT_OSF) {
936 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
937 ds1307->regs[1] & ~DS1337_BIT_OSF);
938 dev_warn(&client->dev, "SET TIME!\n");
943 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
944 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
946 dev_dbg(&client->dev, "read error %d\n", tmp);
951 /* oscillator off? turn it on, so clock can tick. */
952 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
953 ds1307->regs[1] |= RX8025_BIT_XST;
954 i2c_smbus_write_byte_data(client,
955 RX8025_REG_CTRL2 << 4 | 0x08,
957 dev_warn(&client->dev,
958 "oscillator stop detected - SET TIME!\n");
961 if (ds1307->regs[1] & RX8025_BIT_PON) {
962 ds1307->regs[1] &= ~RX8025_BIT_PON;
963 i2c_smbus_write_byte_data(client,
964 RX8025_REG_CTRL2 << 4 | 0x08,
966 dev_warn(&client->dev, "power-on detected\n");
969 if (ds1307->regs[1] & RX8025_BIT_VDET) {
970 ds1307->regs[1] &= ~RX8025_BIT_VDET;
971 i2c_smbus_write_byte_data(client,
972 RX8025_REG_CTRL2 << 4 | 0x08,
974 dev_warn(&client->dev, "voltage drop detected\n");
977 /* make sure we are running in 24hour mode */
978 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
981 /* switch to 24 hour mode */
982 i2c_smbus_write_byte_data(client,
983 RX8025_REG_CTRL1 << 4 | 0x08,
987 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
988 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
990 dev_dbg(&client->dev, "read error %d\n", tmp);
996 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
999 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1002 i2c_smbus_write_byte_data(client,
1003 DS1307_REG_HOUR << 4 | 0x08,
1008 ds1307->offset = 1; /* Seconds starts at 1 */
1011 rtc_ops = &mcp794xx_rtc_ops;
1012 if (ds1307->client->irq > 0 && chip->alarm) {
1013 irq_handler = mcp794xx_irq;
1022 /* read RTC registers */
1023 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
1025 dev_dbg(&client->dev, "read error %d\n", tmp);
1031 * minimal sanity checking; some chips (like DS1340) don't
1032 * specify the extra bits as must-be-zero, but there are
1033 * still a few values that are clearly out-of-range.
1035 tmp = ds1307->regs[DS1307_REG_SECS];
1036 switch (ds1307->type) {
1039 /* clock halted? turn it on, so clock can tick. */
1040 if (tmp & DS1307_BIT_CH) {
1041 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1042 dev_warn(&client->dev, "SET TIME!\n");
1047 /* clock halted? turn it on, so clock can tick. */
1048 if (tmp & DS1307_BIT_CH)
1049 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1051 /* oscillator fault? clear flag, and warn */
1052 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1053 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
1054 ds1307->regs[DS1307_REG_CONTROL]
1056 dev_warn(&client->dev, "SET TIME!\n");
1061 /* clock halted? turn it on, so clock can tick. */
1062 if (tmp & DS1340_BIT_nEOSC)
1063 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1065 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
1067 dev_dbg(&client->dev, "read error %d\n", tmp);
1072 /* oscillator fault? clear flag, and warn */
1073 if (tmp & DS1340_BIT_OSF) {
1074 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
1075 dev_warn(&client->dev, "SET TIME!\n");
1079 /* make sure that the backup battery is enabled */
1080 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1081 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
1082 ds1307->regs[DS1307_REG_WDAY]
1083 | MCP794XX_BIT_VBATEN);
1086 /* clock halted? turn it on, so clock can tick. */
1087 if (!(tmp & MCP794XX_BIT_ST)) {
1088 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
1090 dev_warn(&client->dev, "SET TIME!\n");
1099 tmp = ds1307->regs[DS1307_REG_HOUR];
1100 switch (ds1307->type) {
1104 * NOTE: ignores century bits; fix before deploying
1105 * systems that will run through year 2100.
1111 if (!(tmp & DS1307_BIT_12HR))
1115 * Be sure we're in 24 hour mode. Multi-master systems
1118 tmp = bcd2bin(tmp & 0x1f);
1121 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1123 i2c_smbus_write_byte_data(client,
1124 ds1307->offset + DS1307_REG_HOUR,
1129 device_set_wakeup_capable(&client->dev, true);
1130 set_bit(HAS_ALARM, &ds1307->flags);
1132 ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
1133 rtc_ops, THIS_MODULE);
1134 if (IS_ERR(ds1307->rtc)) {
1135 return PTR_ERR(ds1307->rtc);
1139 err = devm_request_threaded_irq(&client->dev,
1140 client->irq, NULL, irq_handler,
1141 IRQF_SHARED | IRQF_ONESHOT,
1142 ds1307->rtc->name, client);
1145 device_set_wakeup_capable(&client->dev, false);
1146 clear_bit(HAS_ALARM, &ds1307->flags);
1147 dev_err(&client->dev, "unable to request IRQ!\n");
1149 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
1152 if (chip->nvram_size) {
1154 ds1307->nvram = devm_kzalloc(&client->dev,
1155 sizeof(struct bin_attribute),
1157 if (!ds1307->nvram) {
1158 dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
1161 ds1307->nvram->attr.name = "nvram";
1162 ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
1164 sysfs_bin_attr_init(ds1307->nvram);
1166 ds1307->nvram->read = ds1307_nvram_read;
1167 ds1307->nvram->write = ds1307_nvram_write;
1168 ds1307->nvram->size = chip->nvram_size;
1169 ds1307->nvram_offset = chip->nvram_offset;
1171 err = sysfs_create_bin_file(&client->dev.kobj,
1174 dev_err(&client->dev,
1175 "unable to create sysfs file: %s\n",
1176 ds1307->nvram->attr.name);
1178 set_bit(HAS_NVRAM, &ds1307->flags);
1179 dev_info(&client->dev, "%zu bytes nvram\n",
1180 ds1307->nvram->size);
1191 static int ds1307_remove(struct i2c_client *client)
1193 struct ds1307 *ds1307 = i2c_get_clientdata(client);
1195 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
1196 sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
1201 static struct i2c_driver ds1307_driver = {
1203 .name = "rtc-ds1307",
1205 .probe = ds1307_probe,
1206 .remove = ds1307_remove,
1207 .id_table = ds1307_id,
1210 module_i2c_driver(ds1307_driver);
1212 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1213 MODULE_LICENSE("GPL");