2 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
4 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5 * Copyright (C) 2006 Tower Technologies
6 * Copyright (C) 2008 Paul Mundt
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/i2c.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
16 #include <linux/slab.h>
18 #define DRV_VERSION "0.6"
22 * Ricoh has a family of I2C based RTCs, which differ only slightly from
23 * each other. Differences center on pinout (e.g. how many interrupts,
24 * output clock, etc) and how the control registers are used. The '372
25 * is significant only because that's the one this driver first supported.
27 #define RS5C372_REG_SECS 0
28 #define RS5C372_REG_MINS 1
29 #define RS5C372_REG_HOURS 2
30 #define RS5C372_REG_WDAY 3
31 #define RS5C372_REG_DAY 4
32 #define RS5C372_REG_MONTH 5
33 #define RS5C372_REG_YEAR 6
34 #define RS5C372_REG_TRIM 7
35 # define RS5C372_TRIM_XSL 0x80
36 # define RS5C372_TRIM_MASK 0x7F
38 #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
39 #define RS5C_REG_ALARM_A_HOURS 9
40 #define RS5C_REG_ALARM_A_WDAY 10
42 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
43 #define RS5C_REG_ALARM_B_HOURS 12
44 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
46 #define RS5C_REG_CTRL1 14
47 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
48 # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
49 # define RV5C387_CTRL1_24 (1 << 5)
50 # define RS5C372A_CTRL1_SL1 (1 << 5)
51 # define RS5C_CTRL1_CT_MASK (7 << 0)
52 # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
53 # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
54 #define RS5C_REG_CTRL2 15
55 # define RS5C372_CTRL2_24 (1 << 5)
56 # define R2025_CTRL2_XST (1 << 5)
57 # define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2025S/D */
58 # define RS5C_CTRL2_CTFG (1 << 2)
59 # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
60 # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
63 /* to read (style 1) or write registers starting at R */
64 #define RS5C_ADDR(R) (((R) << 4) | 0)
76 static const struct i2c_device_id rs5c372_id
[] = {
77 { "r2025sd", rtc_r2025sd
},
78 { "rs5c372a", rtc_rs5c372a
},
79 { "rs5c372b", rtc_rs5c372b
},
80 { "rv5c386", rtc_rv5c386
},
81 { "rv5c387a", rtc_rv5c387a
},
84 MODULE_DEVICE_TABLE(i2c
, rs5c372_id
);
86 /* REVISIT: this assumes that:
87 * - we're in the 21st century, so it's safe to ignore the century
88 * bit for rv5c38[67] (REG_MONTH bit 7);
89 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
92 struct i2c_client
*client
;
93 struct rtc_device
*rtc
;
102 static int rs5c_get_regs(struct rs5c372
*rs5c
)
104 struct i2c_client
*client
= rs5c
->client
;
105 struct i2c_msg msgs
[] = {
106 { client
->addr
, I2C_M_RD
, sizeof rs5c
->buf
, rs5c
->buf
},
109 /* This implements the third reading method from the datasheet, using
110 * an internal address that's reset after each transaction (by STOP)
111 * to 0x0f ... so we read extra registers, and skip the first one.
113 * The first method doesn't work with the iop3xx adapter driver, on at
114 * least 80219 chips; this works around that bug.
116 * The third method on the other hand doesn't work for the SMBus-only
117 * configurations, so we use the the first method there, stripping off
118 * the extra register in the process.
121 int addr
= RS5C_ADDR(RS5C372_REG_SECS
);
122 int size
= sizeof(rs5c
->buf
) - 1;
124 if (i2c_smbus_read_i2c_block_data(client
, addr
, size
,
125 rs5c
->buf
+ 1) != size
) {
126 dev_warn(&client
->dev
, "can't read registers\n");
130 if ((i2c_transfer(client
->adapter
, msgs
, 1)) != 1) {
131 dev_warn(&client
->dev
, "can't read registers\n");
136 dev_dbg(&client
->dev
,
137 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
138 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
139 rs5c
->regs
[0], rs5c
->regs
[1], rs5c
->regs
[2], rs5c
->regs
[3],
140 rs5c
->regs
[4], rs5c
->regs
[5], rs5c
->regs
[6], rs5c
->regs
[7],
141 rs5c
->regs
[8], rs5c
->regs
[9], rs5c
->regs
[10], rs5c
->regs
[11],
142 rs5c
->regs
[12], rs5c
->regs
[13], rs5c
->regs
[14], rs5c
->regs
[15]);
147 static unsigned rs5c_reg2hr(struct rs5c372
*rs5c
, unsigned reg
)
152 return bcd2bin(reg
& 0x3f);
154 hour
= bcd2bin(reg
& 0x1f);
162 static unsigned rs5c_hr2reg(struct rs5c372
*rs5c
, unsigned hour
)
165 return bin2bcd(hour
);
168 return 0x20 | bin2bcd(hour
- 12);
170 return 0x20 | bin2bcd(12);
173 return bin2bcd(hour
);
176 static int rs5c372_get_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
178 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
179 int status
= rs5c_get_regs(rs5c
);
184 tm
->tm_sec
= bcd2bin(rs5c
->regs
[RS5C372_REG_SECS
] & 0x7f);
185 tm
->tm_min
= bcd2bin(rs5c
->regs
[RS5C372_REG_MINS
] & 0x7f);
186 tm
->tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C372_REG_HOURS
]);
188 tm
->tm_wday
= bcd2bin(rs5c
->regs
[RS5C372_REG_WDAY
] & 0x07);
189 tm
->tm_mday
= bcd2bin(rs5c
->regs
[RS5C372_REG_DAY
] & 0x3f);
191 /* tm->tm_mon is zero-based */
192 tm
->tm_mon
= bcd2bin(rs5c
->regs
[RS5C372_REG_MONTH
] & 0x1f) - 1;
194 /* year is 1900 + tm->tm_year */
195 tm
->tm_year
= bcd2bin(rs5c
->regs
[RS5C372_REG_YEAR
]) + 100;
197 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
198 "mday=%d, mon=%d, year=%d, wday=%d\n",
200 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
201 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
203 /* rtc might need initialization */
204 return rtc_valid_tm(tm
);
207 static int rs5c372_set_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
209 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
210 unsigned char buf
[7];
213 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d "
214 "mday=%d, mon=%d, year=%d, wday=%d\n",
216 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
217 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
219 addr
= RS5C_ADDR(RS5C372_REG_SECS
);
220 buf
[0] = bin2bcd(tm
->tm_sec
);
221 buf
[1] = bin2bcd(tm
->tm_min
);
222 buf
[2] = rs5c_hr2reg(rs5c
, tm
->tm_hour
);
223 buf
[3] = bin2bcd(tm
->tm_wday
);
224 buf
[4] = bin2bcd(tm
->tm_mday
);
225 buf
[5] = bin2bcd(tm
->tm_mon
+ 1);
226 buf
[6] = bin2bcd(tm
->tm_year
- 100);
228 if (i2c_smbus_write_i2c_block_data(client
, addr
, sizeof(buf
), buf
) < 0) {
229 dev_err(&client
->dev
, "%s: write error\n", __func__
);
236 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
240 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
245 static int rs5c372_get_trim(struct i2c_client
*client
, int *osc
, int *trim
)
247 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
248 u8 tmp
= rs5c372
->regs
[RS5C372_REG_TRIM
];
251 *osc
= (tmp
& RS5C372_TRIM_XSL
) ? 32000 : 32768;
254 dev_dbg(&client
->dev
, "%s: raw trim=%x\n", __func__
, tmp
);
255 tmp
&= RS5C372_TRIM_MASK
;
260 t
= (~t
| (s8
)0xc0) + 1;
274 static int rs5c372_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
276 return rs5c372_get_datetime(to_i2c_client(dev
), tm
);
279 static int rs5c372_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
281 return rs5c372_set_datetime(to_i2c_client(dev
), tm
);
285 static int rs5c_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
287 struct i2c_client
*client
= to_i2c_client(dev
);
288 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
292 buf
= rs5c
->regs
[RS5C_REG_CTRL1
];
297 status
= rs5c_get_regs(rs5c
);
301 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
303 buf
|= RS5C_CTRL1_AALE
;
305 buf
&= ~RS5C_CTRL1_AALE
;
307 if (i2c_smbus_write_byte_data(client
, addr
, buf
) < 0) {
308 printk(KERN_WARNING
"%s: can't update alarm\n",
312 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
;
318 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
319 * which only exposes a polled programming interface; and since
320 * these calls map directly to those EFI requests; we don't demand
321 * we have an IRQ for this chip when we go through this API.
323 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
324 * though, managed through RTC_AIE_{ON,OFF} requests.
327 static int rs5c_read_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
329 struct i2c_client
*client
= to_i2c_client(dev
);
330 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
333 status
= rs5c_get_regs(rs5c
);
337 /* report alarm time */
339 t
->time
.tm_min
= bcd2bin(rs5c
->regs
[RS5C_REG_ALARM_A_MIN
] & 0x7f);
340 t
->time
.tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C_REG_ALARM_A_HOURS
]);
341 t
->time
.tm_mday
= -1;
343 t
->time
.tm_year
= -1;
344 t
->time
.tm_wday
= -1;
345 t
->time
.tm_yday
= -1;
346 t
->time
.tm_isdst
= -1;
349 t
->enabled
= !!(rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
);
350 t
->pending
= !!(rs5c
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_AAFG
);
355 static int rs5c_set_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
357 struct i2c_client
*client
= to_i2c_client(dev
);
358 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
360 unsigned char buf
[3];
362 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
363 if (t
->time
.tm_mday
!= -1
364 || t
->time
.tm_mon
!= -1
365 || t
->time
.tm_year
!= -1)
368 /* REVISIT: round up tm_sec */
370 /* if needed, disable irq (clears pending status) */
371 status
= rs5c_get_regs(rs5c
);
374 if (rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
) {
375 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
376 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] & ~RS5C_CTRL1_AALE
;
377 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0) {
378 pr_debug("%s: can't disable alarm\n", rs5c
->rtc
->name
);
381 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
385 buf
[0] = bin2bcd(t
->time
.tm_min
);
386 buf
[1] = rs5c_hr2reg(rs5c
, t
->time
.tm_hour
);
387 buf
[2] = 0x7f; /* any/all days */
389 for (i
= 0; i
< sizeof(buf
); i
++) {
390 addr
= RS5C_ADDR(RS5C_REG_ALARM_A_MIN
+ i
);
391 if (i2c_smbus_write_byte_data(client
, addr
, buf
[i
]) < 0) {
392 pr_debug("%s: can't set alarm time\n", rs5c
->rtc
->name
);
397 /* ... and maybe enable its irq */
399 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
400 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] | RS5C_CTRL1_AALE
;
401 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0)
402 printk(KERN_WARNING
"%s: can't enable alarm\n",
404 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
410 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
412 static int rs5c372_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
416 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, &trim
);
418 seq_printf(seq
, "crystal\t\t: %d.%03d KHz\n",
419 osc
/ 1000, osc
% 1000);
420 seq_printf(seq
, "trim\t\t: %d\n", trim
);
427 #define rs5c372_rtc_proc NULL
430 static const struct rtc_class_ops rs5c372_rtc_ops
= {
431 .proc
= rs5c372_rtc_proc
,
432 .read_time
= rs5c372_rtc_read_time
,
433 .set_time
= rs5c372_rtc_set_time
,
434 .read_alarm
= rs5c_read_alarm
,
435 .set_alarm
= rs5c_set_alarm
,
436 .alarm_irq_enable
= rs5c_rtc_alarm_irq_enable
,
439 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
441 static ssize_t
rs5c372_sysfs_show_trim(struct device
*dev
,
442 struct device_attribute
*attr
, char *buf
)
446 err
= rs5c372_get_trim(to_i2c_client(dev
), NULL
, &trim
);
450 return sprintf(buf
, "%d\n", trim
);
452 static DEVICE_ATTR(trim
, S_IRUGO
, rs5c372_sysfs_show_trim
, NULL
);
454 static ssize_t
rs5c372_sysfs_show_osc(struct device
*dev
,
455 struct device_attribute
*attr
, char *buf
)
459 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, NULL
);
463 return sprintf(buf
, "%d.%03d KHz\n", osc
/ 1000, osc
% 1000);
465 static DEVICE_ATTR(osc
, S_IRUGO
, rs5c372_sysfs_show_osc
, NULL
);
467 static int rs5c_sysfs_register(struct device
*dev
)
471 err
= device_create_file(dev
, &dev_attr_trim
);
474 err
= device_create_file(dev
, &dev_attr_osc
);
476 device_remove_file(dev
, &dev_attr_trim
);
481 static void rs5c_sysfs_unregister(struct device
*dev
)
483 device_remove_file(dev
, &dev_attr_trim
);
484 device_remove_file(dev
, &dev_attr_osc
);
488 static int rs5c_sysfs_register(struct device
*dev
)
493 static void rs5c_sysfs_unregister(struct device
*dev
)
499 static struct i2c_driver rs5c372_driver
;
501 static int rs5c_oscillator_setup(struct rs5c372
*rs5c372
)
503 unsigned char buf
[2];
504 int addr
, i
, ret
= 0;
506 if (rs5c372
->type
== rtc_r2025sd
) {
507 if (!(rs5c372
->regs
[RS5C_REG_CTRL2
] & R2025_CTRL2_XST
))
509 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~R2025_CTRL2_XST
;
511 if (!(rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_XSTP
))
513 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~RS5C_CTRL2_XSTP
;
516 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
517 buf
[0] = rs5c372
->regs
[RS5C_REG_CTRL1
];
518 buf
[1] = rs5c372
->regs
[RS5C_REG_CTRL2
];
521 switch (rs5c372
->type
) {
524 buf
[1] |= RS5C372_CTRL2_24
;
530 buf
[0] |= RV5C387_CTRL1_24
;
538 for (i
= 0; i
< sizeof(buf
); i
++) {
539 addr
= RS5C_ADDR(RS5C_REG_CTRL1
+ i
);
540 ret
= i2c_smbus_write_byte_data(rs5c372
->client
, addr
, buf
[i
]);
541 if (unlikely(ret
< 0))
545 rs5c372
->regs
[RS5C_REG_CTRL1
] = buf
[0];
546 rs5c372
->regs
[RS5C_REG_CTRL2
] = buf
[1];
551 static int rs5c372_probe(struct i2c_client
*client
,
552 const struct i2c_device_id
*id
)
556 struct rs5c372
*rs5c372
;
559 dev_dbg(&client
->dev
, "%s\n", __func__
);
561 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
|
562 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK
)) {
564 * If we don't have any master mode adapter, try breaking
565 * it down in to the barest of capabilities.
567 if (i2c_check_functionality(client
->adapter
,
568 I2C_FUNC_SMBUS_BYTE_DATA
|
569 I2C_FUNC_SMBUS_I2C_BLOCK
))
572 /* Still no good, give up */
578 if (!(rs5c372
= kzalloc(sizeof(struct rs5c372
), GFP_KERNEL
))) {
583 rs5c372
->client
= client
;
584 i2c_set_clientdata(client
, rs5c372
);
585 rs5c372
->type
= id
->driver_data
;
587 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
588 rs5c372
->regs
= &rs5c372
->buf
[1];
589 rs5c372
->smbus
= smbus_mode
;
591 err
= rs5c_get_regs(rs5c372
);
595 /* clock may be set for am/pm or 24 hr time */
596 switch (rs5c372
->type
) {
599 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
600 * so does periodic irq, except some 327a modes.
602 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C372_CTRL2_24
)
608 if (rs5c372
->regs
[RS5C_REG_CTRL1
] & RV5C387_CTRL1_24
)
610 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
611 * irq, on both 386 and 387
615 dev_err(&client
->dev
, "unknown RTC type\n");
619 /* if the oscillator lost power and no other software (like
620 * the bootloader) set it up, do it here.
622 * The R2025S/D does this a little differently than the other
623 * parts, so we special case that..
625 err
= rs5c_oscillator_setup(rs5c372
);
626 if (unlikely(err
< 0)) {
627 dev_err(&client
->dev
, "setup error\n");
631 if (rs5c372_get_datetime(client
, &tm
) < 0)
632 dev_warn(&client
->dev
, "clock needs to be set\n");
634 dev_info(&client
->dev
, "%s found, %s, driver version " DRV_VERSION
"\n",
635 ({ char *s
; switch (rs5c372
->type
) {
636 case rtc_r2025sd
: s
= "r2025sd"; break;
637 case rtc_rs5c372a
: s
= "rs5c372a"; break;
638 case rtc_rs5c372b
: s
= "rs5c372b"; break;
639 case rtc_rv5c386
: s
= "rv5c386"; break;
640 case rtc_rv5c387a
: s
= "rv5c387a"; break;
641 default: s
= "chip"; break;
643 rs5c372
->time24
? "24hr" : "am/pm"
646 /* REVISIT use client->irq to register alarm irq ... */
648 rs5c372
->rtc
= rtc_device_register(rs5c372_driver
.driver
.name
,
649 &client
->dev
, &rs5c372_rtc_ops
, THIS_MODULE
);
651 if (IS_ERR(rs5c372
->rtc
)) {
652 err
= PTR_ERR(rs5c372
->rtc
);
656 err
= rs5c_sysfs_register(&client
->dev
);
663 rtc_device_unregister(rs5c372
->rtc
);
672 static int rs5c372_remove(struct i2c_client
*client
)
674 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
676 rtc_device_unregister(rs5c372
->rtc
);
677 rs5c_sysfs_unregister(&client
->dev
);
682 static struct i2c_driver rs5c372_driver
= {
684 .name
= "rtc-rs5c372",
686 .probe
= rs5c372_probe
,
687 .remove
= rs5c372_remove
,
688 .id_table
= rs5c372_id
,
691 static __init
int rs5c372_init(void)
693 return i2c_add_driver(&rs5c372_driver
);
696 static __exit
void rs5c372_exit(void)
698 i2c_del_driver(&rs5c372_driver
);
701 module_init(rs5c372_init
);
702 module_exit(rs5c372_exit
);
705 "Pavel Mironchik <pmironchik@optifacio.net>, "
706 "Alessandro Zummo <a.zummo@towertech.it>, "
707 "Paul Mundt <lethal@linux-sh.org>");
708 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
709 MODULE_LICENSE("GPL");
710 MODULE_VERSION(DRV_VERSION
);