2 * An I2C driver for Ricoh RS5C372 and RV5C38[67] RTCs
4 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5 * Copyright (C) 2006 Tower Technologies
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/i2c.h>
13 #include <linux/rtc.h>
14 #include <linux/bcd.h>
16 #define DRV_VERSION "0.5"
20 * Ricoh has a family of I2C based RTCs, which differ only slightly from
21 * each other. Differences center on pinout (e.g. how many interrupts,
22 * output clock, etc) and how the control registers are used. The '372
23 * is significant only because that's the one this driver first supported.
25 #define RS5C372_REG_SECS 0
26 #define RS5C372_REG_MINS 1
27 #define RS5C372_REG_HOURS 2
28 #define RS5C372_REG_WDAY 3
29 #define RS5C372_REG_DAY 4
30 #define RS5C372_REG_MONTH 5
31 #define RS5C372_REG_YEAR 6
32 #define RS5C372_REG_TRIM 7
33 # define RS5C372_TRIM_XSL 0x80
34 # define RS5C372_TRIM_MASK 0x7F
36 #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
37 #define RS5C_REG_ALARM_A_HOURS 9
38 #define RS5C_REG_ALARM_A_WDAY 10
40 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
41 #define RS5C_REG_ALARM_B_HOURS 12
42 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
44 #define RS5C_REG_CTRL1 14
45 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
46 # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
47 # define RV5C387_CTRL1_24 (1 << 5)
48 # define RS5C372A_CTRL1_SL1 (1 << 5)
49 # define RS5C_CTRL1_CT_MASK (7 << 0)
50 # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
51 # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
52 #define RS5C_REG_CTRL2 15
53 # define RS5C372_CTRL2_24 (1 << 5)
54 # define RS5C_CTRL2_XSTP (1 << 4)
55 # define RS5C_CTRL2_CTFG (1 << 2)
56 # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
57 # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
60 /* to read (style 1) or write registers starting at R */
61 #define RS5C_ADDR(R) (((R) << 4) | 0)
72 /* REVISIT: this assumes that:
73 * - we're in the 21st century, so it's safe to ignore the century
74 * bit for rv5c38[67] (REG_MONTH bit 7);
75 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
78 struct i2c_client
*client
;
79 struct rtc_device
*rtc
;
87 static int rs5c_get_regs(struct rs5c372
*rs5c
)
89 struct i2c_client
*client
= rs5c
->client
;
90 struct i2c_msg msgs
[] = {
91 { client
->addr
, I2C_M_RD
, sizeof rs5c
->buf
, rs5c
->buf
},
94 /* This implements the third reading method from the datasheet, using
95 * an internal address that's reset after each transaction (by STOP)
96 * to 0x0f ... so we read extra registers, and skip the first one.
98 * The first method doesn't work with the iop3xx adapter driver, on at
99 * least 80219 chips; this works around that bug.
101 if ((i2c_transfer(client
->adapter
, msgs
, 1)) != 1) {
102 pr_debug("%s: can't read registers\n", rs5c
->rtc
->name
);
106 dev_dbg(&client
->dev
,
107 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
108 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
109 rs5c
->regs
[0], rs5c
->regs
[1], rs5c
->regs
[2], rs5c
->regs
[3],
110 rs5c
->regs
[4], rs5c
->regs
[5], rs5c
->regs
[6], rs5c
->regs
[7],
111 rs5c
->regs
[8], rs5c
->regs
[9], rs5c
->regs
[10], rs5c
->regs
[11],
112 rs5c
->regs
[12], rs5c
->regs
[13], rs5c
->regs
[14], rs5c
->regs
[15]);
117 static unsigned rs5c_reg2hr(struct rs5c372
*rs5c
, unsigned reg
)
122 return BCD2BIN(reg
& 0x3f);
124 hour
= BCD2BIN(reg
& 0x1f);
132 static unsigned rs5c_hr2reg(struct rs5c372
*rs5c
, unsigned hour
)
135 return BIN2BCD(hour
);
138 return 0x20 | BIN2BCD(hour
- 12);
140 return 0x20 | BIN2BCD(12);
143 return BIN2BCD(hour
);
146 static int rs5c372_get_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
148 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
149 int status
= rs5c_get_regs(rs5c
);
154 tm
->tm_sec
= BCD2BIN(rs5c
->regs
[RS5C372_REG_SECS
] & 0x7f);
155 tm
->tm_min
= BCD2BIN(rs5c
->regs
[RS5C372_REG_MINS
] & 0x7f);
156 tm
->tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C372_REG_HOURS
]);
158 tm
->tm_wday
= BCD2BIN(rs5c
->regs
[RS5C372_REG_WDAY
] & 0x07);
159 tm
->tm_mday
= BCD2BIN(rs5c
->regs
[RS5C372_REG_DAY
] & 0x3f);
161 /* tm->tm_mon is zero-based */
162 tm
->tm_mon
= BCD2BIN(rs5c
->regs
[RS5C372_REG_MONTH
] & 0x1f) - 1;
164 /* year is 1900 + tm->tm_year */
165 tm
->tm_year
= BCD2BIN(rs5c
->regs
[RS5C372_REG_YEAR
]) + 100;
167 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
168 "mday=%d, mon=%d, year=%d, wday=%d\n",
170 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
171 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
173 /* rtc might need initialization */
174 return rtc_valid_tm(tm
);
177 static int rs5c372_set_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
179 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
180 unsigned char buf
[8];
182 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d "
183 "mday=%d, mon=%d, year=%d, wday=%d\n",
185 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
186 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
188 buf
[0] = RS5C_ADDR(RS5C372_REG_SECS
);
189 buf
[1] = BIN2BCD(tm
->tm_sec
);
190 buf
[2] = BIN2BCD(tm
->tm_min
);
191 buf
[3] = rs5c_hr2reg(rs5c
, tm
->tm_hour
);
192 buf
[4] = BIN2BCD(tm
->tm_wday
);
193 buf
[5] = BIN2BCD(tm
->tm_mday
);
194 buf
[6] = BIN2BCD(tm
->tm_mon
+ 1);
195 buf
[7] = BIN2BCD(tm
->tm_year
- 100);
197 if ((i2c_master_send(client
, buf
, 8)) != 8) {
198 dev_err(&client
->dev
, "%s: write error\n", __FUNCTION__
);
205 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
209 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
214 static int rs5c372_get_trim(struct i2c_client
*client
, int *osc
, int *trim
)
216 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
217 u8 tmp
= rs5c372
->regs
[RS5C372_REG_TRIM
];
220 *osc
= (tmp
& RS5C372_TRIM_XSL
) ? 32000 : 32768;
223 dev_dbg(&client
->dev
, "%s: raw trim=%x\n", __FUNCTION__
, tmp
);
224 tmp
&= RS5C372_TRIM_MASK
;
229 t
= (~t
| (s8
)0xc0) + 1;
243 static int rs5c372_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
245 return rs5c372_get_datetime(to_i2c_client(dev
), tm
);
248 static int rs5c372_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
250 return rs5c372_set_datetime(to_i2c_client(dev
), tm
);
253 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
256 rs5c_rtc_ioctl(struct device
*dev
, unsigned int cmd
, unsigned long arg
)
258 struct i2c_client
*client
= to_i2c_client(dev
);
259 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
260 unsigned char buf
[2];
263 buf
[1] = rs5c
->regs
[RS5C_REG_CTRL1
];
267 /* some 327a modes use a different IRQ pin for 1Hz irqs */
268 if (rs5c
->type
== rtc_rs5c372a
269 && (buf
[1] & RS5C372A_CTRL1_SL1
))
273 /* these irq management calls only make sense for chips
274 * which are wired up to an IRQ.
283 status
= rs5c_get_regs(rs5c
);
287 buf
[0] = RS5C_ADDR(RS5C_REG_CTRL1
);
289 case RTC_AIE_OFF
: /* alarm off */
290 buf
[1] &= ~RS5C_CTRL1_AALE
;
292 case RTC_AIE_ON
: /* alarm on */
293 buf
[1] |= RS5C_CTRL1_AALE
;
295 case RTC_UIE_OFF
: /* update off */
296 buf
[1] &= ~RS5C_CTRL1_CT_MASK
;
298 case RTC_UIE_ON
: /* update on */
299 buf
[1] &= ~RS5C_CTRL1_CT_MASK
;
300 buf
[1] |= RS5C_CTRL1_CT4
;
303 if ((i2c_master_send(client
, buf
, 2)) != 2) {
304 printk(KERN_WARNING
"%s: can't update alarm\n",
308 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[1];
313 #define rs5c_rtc_ioctl NULL
317 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
318 * which only exposes a polled programming interface; and since
319 * these calls map directly to those EFI requests; we don't demand
320 * we have an IRQ for this chip when we go through this API.
322 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
323 * though, managed through RTC_AIE_{ON,OFF} requests.
326 static int rs5c_read_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
328 struct i2c_client
*client
= to_i2c_client(dev
);
329 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
332 status
= rs5c_get_regs(rs5c
);
336 /* report alarm time */
338 t
->time
.tm_min
= BCD2BIN(rs5c
->regs
[RS5C_REG_ALARM_A_MIN
] & 0x7f);
339 t
->time
.tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C_REG_ALARM_A_HOURS
]);
340 t
->time
.tm_mday
= -1;
342 t
->time
.tm_year
= -1;
343 t
->time
.tm_wday
= -1;
344 t
->time
.tm_yday
= -1;
345 t
->time
.tm_isdst
= -1;
348 t
->enabled
= !!(rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
);
349 t
->pending
= !!(rs5c
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_AAFG
);
354 static int rs5c_set_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
356 struct i2c_client
*client
= to_i2c_client(dev
);
357 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
359 unsigned char buf
[4];
361 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
362 if (t
->time
.tm_mday
!= -1
363 || t
->time
.tm_mon
!= -1
364 || t
->time
.tm_year
!= -1)
367 /* REVISIT: round up tm_sec */
369 /* if needed, disable irq (clears pending status) */
370 status
= rs5c_get_regs(rs5c
);
373 if (rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
) {
374 buf
[0] = RS5C_ADDR(RS5C_REG_CTRL1
);
375 buf
[1] = rs5c
->regs
[RS5C_REG_CTRL1
] & ~RS5C_CTRL1_AALE
;
376 if (i2c_master_send(client
, buf
, 2) != 2) {
377 pr_debug("%s: can't disable alarm\n", rs5c
->rtc
->name
);
380 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[1];
384 buf
[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN
);
385 buf
[1] = BIN2BCD(t
->time
.tm_min
);
386 buf
[2] = rs5c_hr2reg(rs5c
, t
->time
.tm_hour
);
387 buf
[3] = 0x7f; /* any/all days */
388 if ((i2c_master_send(client
, buf
, 4)) != 4) {
389 pr_debug("%s: can't set alarm time\n", rs5c
->rtc
->name
);
393 /* ... and maybe enable its irq */
395 buf
[0] = RS5C_ADDR(RS5C_REG_CTRL1
);
396 buf
[1] = rs5c
->regs
[RS5C_REG_CTRL1
] | RS5C_CTRL1_AALE
;
397 if ((i2c_master_send(client
, buf
, 2)) != 2)
398 printk(KERN_WARNING
"%s: can't enable alarm\n",
400 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[1];
406 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
408 static int rs5c372_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
412 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, &trim
);
414 seq_printf(seq
, "crystal\t\t: %d.%03d KHz\n",
415 osc
/ 1000, osc
% 1000);
416 seq_printf(seq
, "trim\t\t: %d\n", trim
);
423 #define rs5c372_rtc_proc NULL
426 static const struct rtc_class_ops rs5c372_rtc_ops
= {
427 .proc
= rs5c372_rtc_proc
,
428 .ioctl
= rs5c_rtc_ioctl
,
429 .read_time
= rs5c372_rtc_read_time
,
430 .set_time
= rs5c372_rtc_set_time
,
431 .read_alarm
= rs5c_read_alarm
,
432 .set_alarm
= rs5c_set_alarm
,
435 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
437 static ssize_t
rs5c372_sysfs_show_trim(struct device
*dev
,
438 struct device_attribute
*attr
, char *buf
)
442 err
= rs5c372_get_trim(to_i2c_client(dev
), NULL
, &trim
);
446 return sprintf(buf
, "%d\n", trim
);
448 static DEVICE_ATTR(trim
, S_IRUGO
, rs5c372_sysfs_show_trim
, NULL
);
450 static ssize_t
rs5c372_sysfs_show_osc(struct device
*dev
,
451 struct device_attribute
*attr
, char *buf
)
455 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, NULL
);
459 return sprintf(buf
, "%d.%03d KHz\n", osc
/ 1000, osc
% 1000);
461 static DEVICE_ATTR(osc
, S_IRUGO
, rs5c372_sysfs_show_osc
, NULL
);
463 static int rs5c_sysfs_register(struct device
*dev
)
467 err
= device_create_file(dev
, &dev_attr_trim
);
470 err
= device_create_file(dev
, &dev_attr_osc
);
472 device_remove_file(dev
, &dev_attr_trim
);
477 static void rs5c_sysfs_unregister(struct device
*dev
)
479 device_remove_file(dev
, &dev_attr_trim
);
480 device_remove_file(dev
, &dev_attr_osc
);
484 static int rs5c_sysfs_register(struct device
*dev
)
489 static void rs5c_sysfs_unregister(struct device
*dev
)
495 static struct i2c_driver rs5c372_driver
;
497 static int rs5c372_probe(struct i2c_client
*client
)
500 struct rs5c372
*rs5c372
;
503 dev_dbg(&client
->dev
, "%s\n", __FUNCTION__
);
505 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
)) {
510 if (!(rs5c372
= kzalloc(sizeof(struct rs5c372
), GFP_KERNEL
))) {
515 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
516 rs5c372
->regs
=&rs5c372
->buf
[1];
518 rs5c372
->client
= client
;
519 i2c_set_clientdata(client
, rs5c372
);
521 err
= rs5c_get_regs(rs5c372
);
525 if (strcmp(client
->name
, "rs5c372a") == 0)
526 rs5c372
->type
= rtc_rs5c372a
;
527 else if (strcmp(client
->name
, "rs5c372b") == 0)
528 rs5c372
->type
= rtc_rs5c372b
;
529 else if (strcmp(client
->name
, "rv5c386") == 0)
530 rs5c372
->type
= rtc_rv5c386
;
531 else if (strcmp(client
->name
, "rv5c387a") == 0)
532 rs5c372
->type
= rtc_rv5c387a
;
534 rs5c372
->type
= rtc_rs5c372b
;
535 dev_warn(&client
->dev
, "assuming rs5c372b\n");
538 /* clock may be set for am/pm or 24 hr time */
539 switch (rs5c372
->type
) {
542 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
543 * so does periodic irq, except some 327a modes.
545 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C372_CTRL2_24
)
550 if (rs5c372
->regs
[RS5C_REG_CTRL1
] & RV5C387_CTRL1_24
)
552 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
553 * irq, on both 386 and 387
557 dev_err(&client
->dev
, "unknown RTC type\n");
561 /* if the oscillator lost power and no other software (like
562 * the bootloader) set it up, do it here.
564 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_XSTP
) {
565 unsigned char buf
[3];
567 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~RS5C_CTRL2_XSTP
;
569 buf
[0] = RS5C_ADDR(RS5C_REG_CTRL1
);
570 buf
[1] = rs5c372
->regs
[RS5C_REG_CTRL1
];
571 buf
[2] = rs5c372
->regs
[RS5C_REG_CTRL2
];
574 switch (rs5c372
->type
) {
577 buf
[2] |= RS5C372_CTRL2_24
;
582 buf
[1] |= RV5C387_CTRL1_24
;
590 if ((i2c_master_send(client
, buf
, 3)) != 3) {
591 dev_err(&client
->dev
, "setup error\n");
594 rs5c372
->regs
[RS5C_REG_CTRL1
] = buf
[1];
595 rs5c372
->regs
[RS5C_REG_CTRL2
] = buf
[2];
598 if (rs5c372_get_datetime(client
, &tm
) < 0)
599 dev_warn(&client
->dev
, "clock needs to be set\n");
601 dev_info(&client
->dev
, "%s found, %s, driver version " DRV_VERSION
"\n",
602 ({ char *s
; switch (rs5c372
->type
) {
603 case rtc_rs5c372a
: s
= "rs5c372a"; break;
604 case rtc_rs5c372b
: s
= "rs5c372b"; break;
605 case rtc_rv5c386
: s
= "rv5c386"; break;
606 case rtc_rv5c387a
: s
= "rv5c387a"; break;
607 default: s
= "chip"; break;
609 rs5c372
->time24
? "24hr" : "am/pm"
612 /* REVISIT use client->irq to register alarm irq ... */
614 rs5c372
->rtc
= rtc_device_register(rs5c372_driver
.driver
.name
,
615 &client
->dev
, &rs5c372_rtc_ops
, THIS_MODULE
);
617 if (IS_ERR(rs5c372
->rtc
)) {
618 err
= PTR_ERR(rs5c372
->rtc
);
622 err
= rs5c_sysfs_register(&client
->dev
);
629 rtc_device_unregister(rs5c372
->rtc
);
638 static int rs5c372_remove(struct i2c_client
*client
)
640 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
642 rtc_device_unregister(rs5c372
->rtc
);
643 rs5c_sysfs_unregister(&client
->dev
);
648 static struct i2c_driver rs5c372_driver
= {
650 .name
= "rtc-rs5c372",
652 .probe
= rs5c372_probe
,
653 .remove
= rs5c372_remove
,
656 static __init
int rs5c372_init(void)
658 return i2c_add_driver(&rs5c372_driver
);
661 static __exit
void rs5c372_exit(void)
663 i2c_del_driver(&rs5c372_driver
);
666 module_init(rs5c372_init
);
667 module_exit(rs5c372_exit
);
670 "Pavel Mironchik <pmironchik@optifacio.net>, "
671 "Alessandro Zummo <a.zummo@towertech.it>");
672 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
673 MODULE_LICENSE("GPL");
674 MODULE_VERSION(DRV_VERSION
);