2 * rtc-fm3130.c - RTC driver for Ramtron FM3130 I2C chip.
4 * Copyright (C) 2008 Sergey Lapin
5 * Based on ds1307 driver by James Chapman and David Brownell
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/i2c.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
16 #include <linux/slab.h>
18 #define FM3130_RTC_CONTROL (0x0)
19 #define FM3130_CAL_CONTROL (0x1)
20 #define FM3130_RTC_SECONDS (0x2)
21 #define FM3130_RTC_MINUTES (0x3)
22 #define FM3130_RTC_HOURS (0x4)
23 #define FM3130_RTC_DAY (0x5)
24 #define FM3130_RTC_DATE (0x6)
25 #define FM3130_RTC_MONTHS (0x7)
26 #define FM3130_RTC_YEARS (0x8)
28 #define FM3130_ALARM_SECONDS (0x9)
29 #define FM3130_ALARM_MINUTES (0xa)
30 #define FM3130_ALARM_HOURS (0xb)
31 #define FM3130_ALARM_DATE (0xc)
32 #define FM3130_ALARM_MONTHS (0xd)
33 #define FM3130_ALARM_WP_CONTROL (0xe)
35 #define FM3130_CAL_CONTROL_BIT_nOSCEN (1 << 7) /* Osciallator enabled */
36 #define FM3130_RTC_CONTROL_BIT_LB (1 << 7) /* Low battery */
37 #define FM3130_RTC_CONTROL_BIT_AF (1 << 6) /* Alarm flag */
38 #define FM3130_RTC_CONTROL_BIT_CF (1 << 5) /* Century overflow */
39 #define FM3130_RTC_CONTROL_BIT_POR (1 << 4) /* Power on reset */
40 #define FM3130_RTC_CONTROL_BIT_AEN (1 << 3) /* Alarm enable */
41 #define FM3130_RTC_CONTROL_BIT_CAL (1 << 2) /* Calibration mode */
42 #define FM3130_RTC_CONTROL_BIT_WRITE (1 << 1) /* W=1 -> write mode W=0 normal */
43 #define FM3130_RTC_CONTROL_BIT_READ (1 << 0) /* R=1 -> read mode R=0 normal */
45 #define FM3130_CLOCK_REGS 7
46 #define FM3130_ALARM_REGS 5
52 struct i2c_msg msg
[4];
53 struct i2c_client
*client
;
54 struct rtc_device
*rtc
;
58 static const struct i2c_device_id fm3130_id
[] = {
62 MODULE_DEVICE_TABLE(i2c
, fm3130_id
);
64 #define FM3130_MODE_NORMAL 0
65 #define FM3130_MODE_WRITE 1
66 #define FM3130_MODE_READ 2
68 static void fm3130_rtc_mode(struct device
*dev
, int mode
)
70 struct fm3130
*fm3130
= dev_get_drvdata(dev
);
72 fm3130
->regs
[FM3130_RTC_CONTROL
] =
73 i2c_smbus_read_byte_data(fm3130
->client
, FM3130_RTC_CONTROL
);
75 case FM3130_MODE_NORMAL
:
76 fm3130
->regs
[FM3130_RTC_CONTROL
] &=
77 ~(FM3130_RTC_CONTROL_BIT_WRITE
|
78 FM3130_RTC_CONTROL_BIT_READ
);
80 case FM3130_MODE_WRITE
:
81 fm3130
->regs
[FM3130_RTC_CONTROL
] |= FM3130_RTC_CONTROL_BIT_WRITE
;
83 case FM3130_MODE_READ
:
84 fm3130
->regs
[FM3130_RTC_CONTROL
] |= FM3130_RTC_CONTROL_BIT_READ
;
87 dev_dbg(dev
, "invalid mode %d\n", mode
);
91 i2c_smbus_write_byte_data(fm3130
->client
,
92 FM3130_RTC_CONTROL
, fm3130
->regs
[FM3130_RTC_CONTROL
]);
95 static int fm3130_get_time(struct device
*dev
, struct rtc_time
*t
)
97 struct fm3130
*fm3130
= dev_get_drvdata(dev
);
100 if (!fm3130
->data_valid
) {
101 /* We have invalid data in RTC, probably due
102 to battery faults or other problems. Return EIO
103 for now, it will allow us to set data later instead
104 of error during probing which disables device */
107 fm3130_rtc_mode(dev
, FM3130_MODE_READ
);
109 /* read the RTC date and time registers all at once */
110 tmp
= i2c_transfer(to_i2c_adapter(fm3130
->client
->dev
.parent
),
113 dev_err(dev
, "%s error %d\n", "read", tmp
);
117 fm3130_rtc_mode(dev
, FM3130_MODE_NORMAL
);
119 dev_dbg(dev
, "%s: %15ph\n", "read", fm3130
->regs
);
121 t
->tm_sec
= bcd2bin(fm3130
->regs
[FM3130_RTC_SECONDS
] & 0x7f);
122 t
->tm_min
= bcd2bin(fm3130
->regs
[FM3130_RTC_MINUTES
] & 0x7f);
123 tmp
= fm3130
->regs
[FM3130_RTC_HOURS
] & 0x3f;
124 t
->tm_hour
= bcd2bin(tmp
);
125 t
->tm_wday
= bcd2bin(fm3130
->regs
[FM3130_RTC_DAY
] & 0x07) - 1;
126 t
->tm_mday
= bcd2bin(fm3130
->regs
[FM3130_RTC_DATE
] & 0x3f);
127 tmp
= fm3130
->regs
[FM3130_RTC_MONTHS
] & 0x1f;
128 t
->tm_mon
= bcd2bin(tmp
) - 1;
130 /* assume 20YY not 19YY, and ignore CF bit */
131 t
->tm_year
= bcd2bin(fm3130
->regs
[FM3130_RTC_YEARS
]) + 100;
133 dev_dbg(dev
, "%s secs=%d, mins=%d, "
134 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
135 "read", t
->tm_sec
, t
->tm_min
,
136 t
->tm_hour
, t
->tm_mday
,
137 t
->tm_mon
, t
->tm_year
, t
->tm_wday
);
143 static int fm3130_set_time(struct device
*dev
, struct rtc_time
*t
)
145 struct fm3130
*fm3130
= dev_get_drvdata(dev
);
147 u8
*buf
= fm3130
->regs
;
149 dev_dbg(dev
, "%s secs=%d, mins=%d, "
150 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
151 "write", t
->tm_sec
, t
->tm_min
,
152 t
->tm_hour
, t
->tm_mday
,
153 t
->tm_mon
, t
->tm_year
, t
->tm_wday
);
155 /* first register addr */
156 buf
[FM3130_RTC_SECONDS
] = bin2bcd(t
->tm_sec
);
157 buf
[FM3130_RTC_MINUTES
] = bin2bcd(t
->tm_min
);
158 buf
[FM3130_RTC_HOURS
] = bin2bcd(t
->tm_hour
);
159 buf
[FM3130_RTC_DAY
] = bin2bcd(t
->tm_wday
+ 1);
160 buf
[FM3130_RTC_DATE
] = bin2bcd(t
->tm_mday
);
161 buf
[FM3130_RTC_MONTHS
] = bin2bcd(t
->tm_mon
+ 1);
163 /* assume 20YY not 19YY */
164 tmp
= t
->tm_year
- 100;
165 buf
[FM3130_RTC_YEARS
] = bin2bcd(tmp
);
167 dev_dbg(dev
, "%s: %15ph\n", "write", buf
);
169 fm3130_rtc_mode(dev
, FM3130_MODE_WRITE
);
171 /* Writing time registers, we don't support multibyte transfers */
172 for (i
= 0; i
< FM3130_CLOCK_REGS
; i
++) {
173 i2c_smbus_write_byte_data(fm3130
->client
,
174 FM3130_RTC_SECONDS
+ i
,
175 fm3130
->regs
[FM3130_RTC_SECONDS
+ i
]);
178 fm3130_rtc_mode(dev
, FM3130_MODE_NORMAL
);
180 /* We assume here that data are valid once written */
181 if (!fm3130
->data_valid
)
182 fm3130
->data_valid
= 1;
186 static int fm3130_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
188 struct fm3130
*fm3130
= dev_get_drvdata(dev
);
190 struct rtc_time
*tm
= &alrm
->time
;
192 if (!fm3130
->alarm_valid
) {
194 * We have invalid alarm in RTC, probably due to battery faults
195 * or other problems. Return EIO for now, it will allow us to
196 * set alarm value later instead of error during probing which
202 /* read the RTC alarm registers all at once */
203 tmp
= i2c_transfer(to_i2c_adapter(fm3130
->client
->dev
.parent
),
206 dev_err(dev
, "%s error %d\n", "read", tmp
);
209 dev_dbg(dev
, "alarm read %02x %02x %02x %02x %02x\n",
210 fm3130
->regs
[FM3130_ALARM_SECONDS
],
211 fm3130
->regs
[FM3130_ALARM_MINUTES
],
212 fm3130
->regs
[FM3130_ALARM_HOURS
],
213 fm3130
->regs
[FM3130_ALARM_DATE
],
214 fm3130
->regs
[FM3130_ALARM_MONTHS
]);
216 tm
->tm_sec
= bcd2bin(fm3130
->regs
[FM3130_ALARM_SECONDS
] & 0x7F);
217 tm
->tm_min
= bcd2bin(fm3130
->regs
[FM3130_ALARM_MINUTES
] & 0x7F);
218 tm
->tm_hour
= bcd2bin(fm3130
->regs
[FM3130_ALARM_HOURS
] & 0x3F);
219 tm
->tm_mday
= bcd2bin(fm3130
->regs
[FM3130_ALARM_DATE
] & 0x3F);
220 tm
->tm_mon
= bcd2bin(fm3130
->regs
[FM3130_ALARM_MONTHS
] & 0x1F);
223 tm
->tm_mon
-= 1; /* RTC is 1-12, tm_mon is 0-11 */
225 dev_dbg(dev
, "%s secs=%d, mins=%d, "
226 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
227 "read alarm", tm
->tm_sec
, tm
->tm_min
,
228 tm
->tm_hour
, tm
->tm_mday
,
229 tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
231 /* check if alarm enabled */
232 fm3130
->regs
[FM3130_RTC_CONTROL
] =
233 i2c_smbus_read_byte_data(fm3130
->client
, FM3130_RTC_CONTROL
);
235 if ((fm3130
->regs
[FM3130_RTC_CONTROL
] & FM3130_RTC_CONTROL_BIT_AEN
) &&
236 (~fm3130
->regs
[FM3130_RTC_CONTROL
] &
237 FM3130_RTC_CONTROL_BIT_CAL
)) {
244 static int fm3130_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
246 struct fm3130
*fm3130
= dev_get_drvdata(dev
);
247 struct rtc_time
*tm
= &alrm
->time
;
250 dev_dbg(dev
, "%s secs=%d, mins=%d, "
251 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
252 "write alarm", tm
->tm_sec
, tm
->tm_min
,
253 tm
->tm_hour
, tm
->tm_mday
,
254 tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
256 fm3130
->regs
[FM3130_ALARM_SECONDS
] =
257 (tm
->tm_sec
!= -1) ? bin2bcd(tm
->tm_sec
) : 0x80;
259 fm3130
->regs
[FM3130_ALARM_MINUTES
] =
260 (tm
->tm_min
!= -1) ? bin2bcd(tm
->tm_min
) : 0x80;
262 fm3130
->regs
[FM3130_ALARM_HOURS
] =
263 (tm
->tm_hour
!= -1) ? bin2bcd(tm
->tm_hour
) : 0x80;
265 fm3130
->regs
[FM3130_ALARM_DATE
] =
266 (tm
->tm_mday
!= -1) ? bin2bcd(tm
->tm_mday
) : 0x80;
268 fm3130
->regs
[FM3130_ALARM_MONTHS
] =
269 (tm
->tm_mon
!= -1) ? bin2bcd(tm
->tm_mon
+ 1) : 0x80;
271 dev_dbg(dev
, "alarm write %02x %02x %02x %02x %02x\n",
272 fm3130
->regs
[FM3130_ALARM_SECONDS
],
273 fm3130
->regs
[FM3130_ALARM_MINUTES
],
274 fm3130
->regs
[FM3130_ALARM_HOURS
],
275 fm3130
->regs
[FM3130_ALARM_DATE
],
276 fm3130
->regs
[FM3130_ALARM_MONTHS
]);
277 /* Writing time registers, we don't support multibyte transfers */
278 for (i
= 0; i
< FM3130_ALARM_REGS
; i
++) {
279 i2c_smbus_write_byte_data(fm3130
->client
,
280 FM3130_ALARM_SECONDS
+ i
,
281 fm3130
->regs
[FM3130_ALARM_SECONDS
+ i
]);
283 fm3130
->regs
[FM3130_RTC_CONTROL
] =
284 i2c_smbus_read_byte_data(fm3130
->client
, FM3130_RTC_CONTROL
);
286 /* enable or disable alarm */
288 i2c_smbus_write_byte_data(fm3130
->client
, FM3130_RTC_CONTROL
,
289 (fm3130
->regs
[FM3130_RTC_CONTROL
] &
290 ~(FM3130_RTC_CONTROL_BIT_CAL
)) |
291 FM3130_RTC_CONTROL_BIT_AEN
);
293 i2c_smbus_write_byte_data(fm3130
->client
, FM3130_RTC_CONTROL
,
294 fm3130
->regs
[FM3130_RTC_CONTROL
] &
295 ~(FM3130_RTC_CONTROL_BIT_CAL
) &
296 ~(FM3130_RTC_CONTROL_BIT_AEN
));
299 /* We assume here that data is valid once written */
300 if (!fm3130
->alarm_valid
)
301 fm3130
->alarm_valid
= 1;
306 static int fm3130_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
308 struct fm3130
*fm3130
= dev_get_drvdata(dev
);
311 fm3130
->regs
[FM3130_RTC_CONTROL
] =
312 i2c_smbus_read_byte_data(fm3130
->client
, FM3130_RTC_CONTROL
);
314 dev_dbg(dev
, "alarm_irq_enable: enable=%d, FM3130_RTC_CONTROL=%02x\n",
315 enabled
, fm3130
->regs
[FM3130_RTC_CONTROL
]);
318 case 0: /* alarm off */
319 ret
= i2c_smbus_write_byte_data(fm3130
->client
,
320 FM3130_RTC_CONTROL
, fm3130
->regs
[FM3130_RTC_CONTROL
] &
321 ~(FM3130_RTC_CONTROL_BIT_CAL
) &
322 ~(FM3130_RTC_CONTROL_BIT_AEN
));
324 case 1: /* alarm on */
325 ret
= i2c_smbus_write_byte_data(fm3130
->client
,
326 FM3130_RTC_CONTROL
, (fm3130
->regs
[FM3130_RTC_CONTROL
] &
327 ~(FM3130_RTC_CONTROL_BIT_CAL
)) |
328 FM3130_RTC_CONTROL_BIT_AEN
);
338 static const struct rtc_class_ops fm3130_rtc_ops
= {
339 .read_time
= fm3130_get_time
,
340 .set_time
= fm3130_set_time
,
341 .read_alarm
= fm3130_read_alarm
,
342 .set_alarm
= fm3130_set_alarm
,
343 .alarm_irq_enable
= fm3130_alarm_irq_enable
,
346 static struct i2c_driver fm3130_driver
;
348 static int fm3130_probe(struct i2c_client
*client
,
349 const struct i2c_device_id
*id
)
351 struct fm3130
*fm3130
;
354 struct i2c_adapter
*adapter
= to_i2c_adapter(client
->dev
.parent
);
356 if (!i2c_check_functionality(adapter
,
357 I2C_FUNC_I2C
| I2C_FUNC_SMBUS_WRITE_BYTE_DATA
))
360 fm3130
= devm_kzalloc(&client
->dev
, sizeof(struct fm3130
), GFP_KERNEL
);
365 fm3130
->client
= client
;
366 i2c_set_clientdata(client
, fm3130
);
367 fm3130
->reg_addr_time
= FM3130_RTC_SECONDS
;
368 fm3130
->reg_addr_alarm
= FM3130_ALARM_SECONDS
;
370 /* Messages to read time */
371 fm3130
->msg
[0].addr
= client
->addr
;
372 fm3130
->msg
[0].flags
= 0;
373 fm3130
->msg
[0].len
= 1;
374 fm3130
->msg
[0].buf
= &fm3130
->reg_addr_time
;
376 fm3130
->msg
[1].addr
= client
->addr
;
377 fm3130
->msg
[1].flags
= I2C_M_RD
;
378 fm3130
->msg
[1].len
= FM3130_CLOCK_REGS
;
379 fm3130
->msg
[1].buf
= &fm3130
->regs
[FM3130_RTC_SECONDS
];
381 /* Messages to read alarm */
382 fm3130
->msg
[2].addr
= client
->addr
;
383 fm3130
->msg
[2].flags
= 0;
384 fm3130
->msg
[2].len
= 1;
385 fm3130
->msg
[2].buf
= &fm3130
->reg_addr_alarm
;
387 fm3130
->msg
[3].addr
= client
->addr
;
388 fm3130
->msg
[3].flags
= I2C_M_RD
;
389 fm3130
->msg
[3].len
= FM3130_ALARM_REGS
;
390 fm3130
->msg
[3].buf
= &fm3130
->regs
[FM3130_ALARM_SECONDS
];
392 fm3130
->alarm_valid
= 0;
393 fm3130
->data_valid
= 0;
395 tmp
= i2c_transfer(adapter
, fm3130
->msg
, 4);
397 dev_dbg(&client
->dev
, "read error %d\n", tmp
);
402 fm3130
->regs
[FM3130_RTC_CONTROL
] =
403 i2c_smbus_read_byte_data(client
, FM3130_RTC_CONTROL
);
404 fm3130
->regs
[FM3130_CAL_CONTROL
] =
405 i2c_smbus_read_byte_data(client
, FM3130_CAL_CONTROL
);
407 /* Disabling calibration mode */
408 if (fm3130
->regs
[FM3130_RTC_CONTROL
] & FM3130_RTC_CONTROL_BIT_CAL
) {
409 i2c_smbus_write_byte_data(client
, FM3130_RTC_CONTROL
,
410 fm3130
->regs
[FM3130_RTC_CONTROL
] &
411 ~(FM3130_RTC_CONTROL_BIT_CAL
));
412 dev_warn(&client
->dev
, "Disabling calibration mode!\n");
415 /* Disabling read and write modes */
416 if (fm3130
->regs
[FM3130_RTC_CONTROL
] & FM3130_RTC_CONTROL_BIT_WRITE
||
417 fm3130
->regs
[FM3130_RTC_CONTROL
] & FM3130_RTC_CONTROL_BIT_READ
) {
418 i2c_smbus_write_byte_data(client
, FM3130_RTC_CONTROL
,
419 fm3130
->regs
[FM3130_RTC_CONTROL
] &
420 ~(FM3130_RTC_CONTROL_BIT_READ
|
421 FM3130_RTC_CONTROL_BIT_WRITE
));
422 dev_warn(&client
->dev
, "Disabling READ or WRITE mode!\n");
425 /* oscillator off? turn it on, so clock can tick. */
426 if (fm3130
->regs
[FM3130_CAL_CONTROL
] & FM3130_CAL_CONTROL_BIT_nOSCEN
)
427 i2c_smbus_write_byte_data(client
, FM3130_CAL_CONTROL
,
428 fm3130
->regs
[FM3130_CAL_CONTROL
] &
429 ~(FM3130_CAL_CONTROL_BIT_nOSCEN
));
431 /* low battery? clear flag, and warn */
432 if (fm3130
->regs
[FM3130_RTC_CONTROL
] & FM3130_RTC_CONTROL_BIT_LB
) {
433 i2c_smbus_write_byte_data(client
, FM3130_RTC_CONTROL
,
434 fm3130
->regs
[FM3130_RTC_CONTROL
] &
435 ~(FM3130_RTC_CONTROL_BIT_LB
));
436 dev_warn(&client
->dev
, "Low battery!\n");
439 /* check if Power On Reset bit is set */
440 if (fm3130
->regs
[FM3130_RTC_CONTROL
] & FM3130_RTC_CONTROL_BIT_POR
) {
441 i2c_smbus_write_byte_data(client
, FM3130_RTC_CONTROL
,
442 fm3130
->regs
[FM3130_RTC_CONTROL
] &
443 ~FM3130_RTC_CONTROL_BIT_POR
);
444 dev_dbg(&client
->dev
, "POR bit is set\n");
446 /* ACS is controlled by alarm */
447 i2c_smbus_write_byte_data(client
, FM3130_ALARM_WP_CONTROL
, 0x80);
449 /* alarm registers sanity check */
450 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_SECONDS
] & 0x7f);
454 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_MINUTES
] & 0x7f);
458 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_HOURS
] & 0x3f);
462 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_DATE
] & 0x3f);
463 if (tmp
== 0 || tmp
> 31)
466 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_MONTHS
] & 0x1f);
467 if (tmp
== 0 || tmp
> 12)
470 fm3130
->alarm_valid
= 1;
474 /* clock registers sanity chek */
475 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_SECONDS
] & 0x7f);
479 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_MINUTES
] & 0x7f);
483 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_HOURS
] & 0x3f);
487 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_DAY
] & 0x7);
488 if (tmp
== 0 || tmp
> 7)
491 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_DATE
] & 0x3f);
492 if (tmp
== 0 || tmp
> 31)
495 tmp
= bcd2bin(fm3130
->regs
[FM3130_RTC_MONTHS
] & 0x1f);
496 if (tmp
== 0 || tmp
> 12)
499 fm3130
->data_valid
= 1;
503 if (!fm3130
->data_valid
|| !fm3130
->alarm_valid
)
504 dev_dbg(&client
->dev
, "%s: %15ph\n", "bogus registers",
507 /* We won't bail out here because we just got invalid data.
508 Time setting from u-boot doesn't work anyway */
509 fm3130
->rtc
= devm_rtc_device_register(&client
->dev
, client
->name
,
510 &fm3130_rtc_ops
, THIS_MODULE
);
511 if (IS_ERR(fm3130
->rtc
)) {
512 err
= PTR_ERR(fm3130
->rtc
);
513 dev_err(&client
->dev
,
514 "unable to register the class device\n");
522 static struct i2c_driver fm3130_driver
= {
524 .name
= "rtc-fm3130",
526 .probe
= fm3130_probe
,
527 .id_table
= fm3130_id
,
530 module_i2c_driver(fm3130_driver
);
532 MODULE_DESCRIPTION("RTC driver for FM3130");
533 MODULE_AUTHOR("Sergey Lapin <slapin@ossfans.org>");
534 MODULE_LICENSE("GPL");