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");