2 * Intersil ISL1208 rtc class driver
4 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/bcd.h>
16 #include <linux/rtc.h>
18 #define DRV_VERSION "0.3"
22 #define ISL1208_REG_SC 0x00
23 #define ISL1208_REG_MN 0x01
24 #define ISL1208_REG_HR 0x02
25 #define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
26 #define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
27 #define ISL1208_REG_DT 0x03
28 #define ISL1208_REG_MO 0x04
29 #define ISL1208_REG_YR 0x05
30 #define ISL1208_REG_DW 0x06
31 #define ISL1208_RTC_SECTION_LEN 7
33 /* control/status section */
34 #define ISL1208_REG_SR 0x07
35 #define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
36 #define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
37 #define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
38 #define ISL1208_REG_SR_ALM (1<<2) /* alarm */
39 #define ISL1208_REG_SR_BAT (1<<1) /* battery */
40 #define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
41 #define ISL1208_REG_INT 0x08
42 #define ISL1208_REG_09 0x09 /* reserved */
43 #define ISL1208_REG_ATR 0x0a
44 #define ISL1208_REG_DTR 0x0b
47 #define ISL1208_REG_SCA 0x0c
48 #define ISL1208_REG_MNA 0x0d
49 #define ISL1208_REG_HRA 0x0e
50 #define ISL1208_REG_DTA 0x0f
51 #define ISL1208_REG_MOA 0x10
52 #define ISL1208_REG_DWA 0x11
53 #define ISL1208_ALARM_SECTION_LEN 6
56 #define ISL1208_REG_USR1 0x12
57 #define ISL1208_REG_USR2 0x13
58 #define ISL1208_USR_SECTION_LEN 2
60 static struct i2c_driver isl1208_driver
;
64 isl1208_i2c_read_regs(struct i2c_client
*client
, u8 reg
, u8 buf
[],
67 u8 reg_addr
[1] = { reg
};
68 struct i2c_msg msgs
[2] = {
69 {client
->addr
, 0, sizeof(reg_addr
), reg_addr
}
71 {client
->addr
, I2C_M_RD
, len
, buf
}
75 BUG_ON(reg
> ISL1208_REG_USR2
);
76 BUG_ON(reg
+ len
> ISL1208_REG_USR2
+ 1);
78 ret
= i2c_transfer(client
->adapter
, msgs
, 2);
86 isl1208_i2c_set_regs(struct i2c_client
*client
, u8 reg
, u8
const buf
[],
89 u8 i2c_buf
[ISL1208_REG_USR2
+ 2];
90 struct i2c_msg msgs
[1] = {
91 {client
->addr
, 0, len
+ 1, i2c_buf
}
95 BUG_ON(reg
> ISL1208_REG_USR2
);
96 BUG_ON(reg
+ len
> ISL1208_REG_USR2
+ 1);
99 memcpy(&i2c_buf
[1], &buf
[0], len
);
101 ret
= i2c_transfer(client
->adapter
, msgs
, 1);
107 /* simple check to see wether we have a isl1208 */
109 isl1208_i2c_validate_client(struct i2c_client
*client
)
111 u8 regs
[ISL1208_RTC_SECTION_LEN
] = { 0, };
112 u8 zero_mask
[ISL1208_RTC_SECTION_LEN
] = {
113 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
118 ret
= isl1208_i2c_read_regs(client
, 0, regs
, ISL1208_RTC_SECTION_LEN
);
122 for (i
= 0; i
< ISL1208_RTC_SECTION_LEN
; ++i
) {
123 if (regs
[i
] & zero_mask
[i
]) /* check if bits are cleared */
131 isl1208_i2c_get_sr(struct i2c_client
*client
)
133 int sr
= i2c_smbus_read_byte_data(client
, ISL1208_REG_SR
);
141 isl1208_i2c_get_atr(struct i2c_client
*client
)
143 int atr
= i2c_smbus_read_byte_data(client
, ISL1208_REG_ATR
);
147 /* The 6bit value in the ATR register controls the load
148 * capacitance C_load * in steps of 0.25pF
150 * bit (1<<5) of the ATR register is inverted
152 * C_load(ATR=0x20) = 4.50pF
153 * C_load(ATR=0x00) = 12.50pF
154 * C_load(ATR=0x1f) = 20.25pF
158 atr
&= 0x3f; /* mask out lsb */
159 atr
^= 1 << 5; /* invert 6th bit */
160 atr
+= 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
166 isl1208_i2c_get_dtr(struct i2c_client
*client
)
168 int dtr
= i2c_smbus_read_byte_data(client
, ISL1208_REG_DTR
);
172 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
173 dtr
= ((dtr
& 0x3) * 20) * (dtr
& (1 << 2) ? -1 : 1);
179 isl1208_i2c_get_usr(struct i2c_client
*client
)
181 u8 buf
[ISL1208_USR_SECTION_LEN
] = { 0, };
184 ret
= isl1208_i2c_read_regs(client
, ISL1208_REG_USR1
, buf
,
185 ISL1208_USR_SECTION_LEN
);
189 return (buf
[1] << 8) | buf
[0];
193 isl1208_i2c_set_usr(struct i2c_client
*client
, u16 usr
)
195 u8 buf
[ISL1208_USR_SECTION_LEN
];
198 buf
[1] = (usr
>> 8) & 0xff;
200 return isl1208_i2c_set_regs(client
, ISL1208_REG_USR1
, buf
,
201 ISL1208_USR_SECTION_LEN
);
205 isl1208_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
207 struct i2c_client
*const client
= to_i2c_client(dev
);
208 int sr
, dtr
, atr
, usr
;
210 sr
= isl1208_i2c_get_sr(client
);
212 dev_err(&client
->dev
, "%s: reading SR failed\n", __func__
);
216 seq_printf(seq
, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
217 (sr
& ISL1208_REG_SR_RTCF
) ? " RTCF" : "",
218 (sr
& ISL1208_REG_SR_BAT
) ? " BAT" : "",
219 (sr
& ISL1208_REG_SR_ALM
) ? " ALM" : "",
220 (sr
& ISL1208_REG_SR_WRTC
) ? " WRTC" : "",
221 (sr
& ISL1208_REG_SR_XTOSCB
) ? " XTOSCB" : "",
222 (sr
& ISL1208_REG_SR_ARST
) ? " ARST" : "", sr
);
224 seq_printf(seq
, "batt_status\t: %s\n",
225 (sr
& ISL1208_REG_SR_RTCF
) ? "bad" : "okay");
227 dtr
= isl1208_i2c_get_dtr(client
);
229 seq_printf(seq
, "digital_trim\t: %d ppm\n", dtr
);
231 atr
= isl1208_i2c_get_atr(client
);
233 seq_printf(seq
, "analog_trim\t: %d.%.2d pF\n",
234 atr
>> 2, (atr
& 0x3) * 25);
236 usr
= isl1208_i2c_get_usr(client
);
238 seq_printf(seq
, "user_data\t: 0x%.4x\n", usr
);
244 isl1208_i2c_read_time(struct i2c_client
*client
, struct rtc_time
*tm
)
247 u8 regs
[ISL1208_RTC_SECTION_LEN
] = { 0, };
249 sr
= isl1208_i2c_get_sr(client
);
251 dev_err(&client
->dev
, "%s: reading SR failed\n", __func__
);
255 sr
= isl1208_i2c_read_regs(client
, 0, regs
, ISL1208_RTC_SECTION_LEN
);
257 dev_err(&client
->dev
, "%s: reading RTC section failed\n",
262 tm
->tm_sec
= BCD2BIN(regs
[ISL1208_REG_SC
]);
263 tm
->tm_min
= BCD2BIN(regs
[ISL1208_REG_MN
]);
265 /* HR field has a more complex interpretation */
267 const u8 _hr
= regs
[ISL1208_REG_HR
];
268 if (_hr
& ISL1208_REG_HR_MIL
) /* 24h format */
269 tm
->tm_hour
= BCD2BIN(_hr
& 0x3f);
272 tm
->tm_hour
= BCD2BIN(_hr
& 0x1f);
273 if (_hr
& ISL1208_REG_HR_PM
) /* PM flag set */
278 tm
->tm_mday
= BCD2BIN(regs
[ISL1208_REG_DT
]);
279 tm
->tm_mon
= BCD2BIN(regs
[ISL1208_REG_MO
]) - 1; /* rtc starts at 1 */
280 tm
->tm_year
= BCD2BIN(regs
[ISL1208_REG_YR
]) + 100;
281 tm
->tm_wday
= BCD2BIN(regs
[ISL1208_REG_DW
]);
287 isl1208_i2c_read_alarm(struct i2c_client
*client
, struct rtc_wkalrm
*alarm
)
289 struct rtc_time
*const tm
= &alarm
->time
;
290 u8 regs
[ISL1208_ALARM_SECTION_LEN
] = { 0, };
293 sr
= isl1208_i2c_get_sr(client
);
295 dev_err(&client
->dev
, "%s: reading SR failed\n", __func__
);
299 sr
= isl1208_i2c_read_regs(client
, ISL1208_REG_SCA
, regs
,
300 ISL1208_ALARM_SECTION_LEN
);
302 dev_err(&client
->dev
, "%s: reading alarm section failed\n",
307 /* MSB of each alarm register is an enable bit */
308 tm
->tm_sec
= BCD2BIN(regs
[ISL1208_REG_SCA
- ISL1208_REG_SCA
] & 0x7f);
309 tm
->tm_min
= BCD2BIN(regs
[ISL1208_REG_MNA
- ISL1208_REG_SCA
] & 0x7f);
310 tm
->tm_hour
= BCD2BIN(regs
[ISL1208_REG_HRA
- ISL1208_REG_SCA
] & 0x3f);
311 tm
->tm_mday
= BCD2BIN(regs
[ISL1208_REG_DTA
- ISL1208_REG_SCA
] & 0x3f);
313 BCD2BIN(regs
[ISL1208_REG_MOA
- ISL1208_REG_SCA
] & 0x1f) - 1;
314 tm
->tm_wday
= BCD2BIN(regs
[ISL1208_REG_DWA
- ISL1208_REG_SCA
] & 0x03);
320 isl1208_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
322 return isl1208_i2c_read_time(to_i2c_client(dev
), tm
);
326 isl1208_i2c_set_time(struct i2c_client
*client
, struct rtc_time
const *tm
)
329 u8 regs
[ISL1208_RTC_SECTION_LEN
] = { 0, };
331 regs
[ISL1208_REG_SC
] = BIN2BCD(tm
->tm_sec
);
332 regs
[ISL1208_REG_MN
] = BIN2BCD(tm
->tm_min
);
333 regs
[ISL1208_REG_HR
] = BIN2BCD(tm
->tm_hour
) | ISL1208_REG_HR_MIL
;
335 regs
[ISL1208_REG_DT
] = BIN2BCD(tm
->tm_mday
);
336 regs
[ISL1208_REG_MO
] = BIN2BCD(tm
->tm_mon
+ 1);
337 regs
[ISL1208_REG_YR
] = BIN2BCD(tm
->tm_year
- 100);
339 regs
[ISL1208_REG_DW
] = BIN2BCD(tm
->tm_wday
& 7);
341 sr
= isl1208_i2c_get_sr(client
);
343 dev_err(&client
->dev
, "%s: reading SR failed\n", __func__
);
348 sr
= i2c_smbus_write_byte_data(client
, ISL1208_REG_SR
,
349 sr
| ISL1208_REG_SR_WRTC
);
351 dev_err(&client
->dev
, "%s: writing SR failed\n", __func__
);
355 /* write RTC registers */
356 sr
= isl1208_i2c_set_regs(client
, 0, regs
, ISL1208_RTC_SECTION_LEN
);
358 dev_err(&client
->dev
, "%s: writing RTC section failed\n",
363 /* clear WRTC again */
364 sr
= i2c_smbus_write_byte_data(client
, ISL1208_REG_SR
,
365 sr
& ~ISL1208_REG_SR_WRTC
);
367 dev_err(&client
->dev
, "%s: writing SR failed\n", __func__
);
376 isl1208_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
378 return isl1208_i2c_set_time(to_i2c_client(dev
), tm
);
382 isl1208_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
384 return isl1208_i2c_read_alarm(to_i2c_client(dev
), alarm
);
387 static const struct rtc_class_ops isl1208_rtc_ops
= {
388 .proc
= isl1208_rtc_proc
,
389 .read_time
= isl1208_rtc_read_time
,
390 .set_time
= isl1208_rtc_set_time
,
391 .read_alarm
= isl1208_rtc_read_alarm
,
392 /*.set_alarm = isl1208_rtc_set_alarm, */
395 /* sysfs interface */
398 isl1208_sysfs_show_atrim(struct device
*dev
,
399 struct device_attribute
*attr
, char *buf
)
401 int atr
= isl1208_i2c_get_atr(to_i2c_client(dev
));
405 return sprintf(buf
, "%d.%.2d pF\n", atr
>> 2, (atr
& 0x3) * 25);
408 static DEVICE_ATTR(atrim
, S_IRUGO
, isl1208_sysfs_show_atrim
, NULL
);
411 isl1208_sysfs_show_dtrim(struct device
*dev
,
412 struct device_attribute
*attr
, char *buf
)
414 int dtr
= isl1208_i2c_get_dtr(to_i2c_client(dev
));
418 return sprintf(buf
, "%d ppm\n", dtr
);
421 static DEVICE_ATTR(dtrim
, S_IRUGO
, isl1208_sysfs_show_dtrim
, NULL
);
424 isl1208_sysfs_show_usr(struct device
*dev
,
425 struct device_attribute
*attr
, char *buf
)
427 int usr
= isl1208_i2c_get_usr(to_i2c_client(dev
));
431 return sprintf(buf
, "0x%.4x\n", usr
);
435 isl1208_sysfs_store_usr(struct device
*dev
,
436 struct device_attribute
*attr
,
437 const char *buf
, size_t count
)
441 if (buf
[0] == '0' && (buf
[1] == 'x' || buf
[1] == 'X')) {
442 if (sscanf(buf
, "%x", &usr
) != 1)
445 if (sscanf(buf
, "%d", &usr
) != 1)
449 if (usr
< 0 || usr
> 0xffff)
452 return isl1208_i2c_set_usr(to_i2c_client(dev
), usr
) ? -EIO
: count
;
455 static DEVICE_ATTR(usr
, S_IRUGO
| S_IWUSR
, isl1208_sysfs_show_usr
,
456 isl1208_sysfs_store_usr
);
459 isl1208_sysfs_register(struct device
*dev
)
463 err
= device_create_file(dev
, &dev_attr_atrim
);
467 err
= device_create_file(dev
, &dev_attr_dtrim
);
469 device_remove_file(dev
, &dev_attr_atrim
);
473 err
= device_create_file(dev
, &dev_attr_usr
);
475 device_remove_file(dev
, &dev_attr_atrim
);
476 device_remove_file(dev
, &dev_attr_dtrim
);
483 isl1208_sysfs_unregister(struct device
*dev
)
485 device_remove_file(dev
, &dev_attr_dtrim
);
486 device_remove_file(dev
, &dev_attr_atrim
);
487 device_remove_file(dev
, &dev_attr_usr
);
493 isl1208_probe(struct i2c_client
*client
, const struct i2c_device_id
*id
)
496 struct rtc_device
*rtc
;
498 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
))
501 if (isl1208_i2c_validate_client(client
) < 0)
504 dev_info(&client
->dev
,
505 "chip found, driver version " DRV_VERSION
"\n");
507 rtc
= rtc_device_register(isl1208_driver
.driver
.name
,
508 &client
->dev
, &isl1208_rtc_ops
,
513 i2c_set_clientdata(client
, rtc
);
515 rc
= isl1208_i2c_get_sr(client
);
517 dev_err(&client
->dev
, "reading status failed\n");
518 goto exit_unregister
;
521 if (rc
& ISL1208_REG_SR_RTCF
)
522 dev_warn(&client
->dev
, "rtc power failure detected, "
523 "please set clock.\n");
525 rc
= isl1208_sysfs_register(&client
->dev
);
527 goto exit_unregister
;
532 rtc_device_unregister(rtc
);
538 isl1208_remove(struct i2c_client
*client
)
540 struct rtc_device
*rtc
= i2c_get_clientdata(client
);
542 isl1208_sysfs_unregister(&client
->dev
);
543 rtc_device_unregister(rtc
);
548 static const struct i2c_device_id isl1208_id
[] = {
552 MODULE_DEVICE_TABLE(i2c
, isl1208_id
);
554 static struct i2c_driver isl1208_driver
= {
556 .name
= "rtc-isl1208",
558 .probe
= isl1208_probe
,
559 .remove
= isl1208_remove
,
560 .id_table
= isl1208_id
,
566 return i2c_add_driver(&isl1208_driver
);
572 i2c_del_driver(&isl1208_driver
);
575 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
576 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
577 MODULE_LICENSE("GPL");
578 MODULE_VERSION(DRV_VERSION
);
580 module_init(isl1208_init
);
581 module_exit(isl1208_exit
);