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>
17 #include <linux/module.h>
18 #include <linux/of_device.h>
21 * Ricoh has a family of I2C based RTCs, which differ only slightly from
22 * each other. Differences center on pinout (e.g. how many interrupts,
23 * output clock, etc) and how the control registers are used. The '372
24 * is significant only because that's the one this driver first supported.
26 #define RS5C372_REG_SECS 0
27 #define RS5C372_REG_MINS 1
28 #define RS5C372_REG_HOURS 2
29 #define RS5C372_REG_WDAY 3
30 #define RS5C372_REG_DAY 4
31 #define RS5C372_REG_MONTH 5
32 #define RS5C372_REG_YEAR 6
33 #define RS5C372_REG_TRIM 7
34 # define RS5C372_TRIM_XSL 0x80
35 # define RS5C372_TRIM_MASK 0x7F
37 #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
38 #define RS5C_REG_ALARM_A_HOURS 9
39 #define RS5C_REG_ALARM_A_WDAY 10
41 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
42 #define RS5C_REG_ALARM_B_HOURS 12
43 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
45 #define RS5C_REG_CTRL1 14
46 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
47 # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
48 # define RV5C387_CTRL1_24 (1 << 5)
49 # define RS5C372A_CTRL1_SL1 (1 << 5)
50 # define RS5C_CTRL1_CT_MASK (7 << 0)
51 # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
52 # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
53 #define RS5C_REG_CTRL2 15
54 # define RS5C372_CTRL2_24 (1 << 5)
55 # define R2025_CTRL2_XST (1 << 5)
56 # define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2025S/D */
57 # define RS5C_CTRL2_CTFG (1 << 2)
58 # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
59 # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
62 /* to read (style 1) or write registers starting at R */
63 #define RS5C_ADDR(R) (((R) << 4) | 0)
76 static const struct i2c_device_id rs5c372_id
[] = {
77 { "r2025sd", rtc_r2025sd
},
78 { "r2221tl", rtc_r2221tl
},
79 { "rs5c372a", rtc_rs5c372a
},
80 { "rs5c372b", rtc_rs5c372b
},
81 { "rv5c386", rtc_rv5c386
},
82 { "rv5c387a", rtc_rv5c387a
},
85 MODULE_DEVICE_TABLE(i2c
, rs5c372_id
);
87 static const struct of_device_id rs5c372_of_match
[] = {
89 .compatible
= "ricoh,r2025sd",
90 .data
= (void *)rtc_r2025sd
93 .compatible
= "ricoh,r2221tl",
94 .data
= (void *)rtc_r2221tl
97 .compatible
= "ricoh,rs5c372a",
98 .data
= (void *)rtc_rs5c372a
101 .compatible
= "ricoh,rs5c372b",
102 .data
= (void *)rtc_rs5c372b
105 .compatible
= "ricoh,rv5c386",
106 .data
= (void *)rtc_rv5c386
109 .compatible
= "ricoh,rv5c387a",
110 .data
= (void *)rtc_rv5c387a
114 MODULE_DEVICE_TABLE(of
, rs5c372_of_match
);
116 /* REVISIT: this assumes that:
117 * - we're in the 21st century, so it's safe to ignore the century
118 * bit for rv5c38[67] (REG_MONTH bit 7);
119 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
122 struct i2c_client
*client
;
123 struct rtc_device
*rtc
;
132 static int rs5c_get_regs(struct rs5c372
*rs5c
)
134 struct i2c_client
*client
= rs5c
->client
;
135 struct i2c_msg msgs
[] = {
137 .addr
= client
->addr
,
139 .len
= sizeof(rs5c
->buf
),
144 /* This implements the third reading method from the datasheet, using
145 * an internal address that's reset after each transaction (by STOP)
146 * to 0x0f ... so we read extra registers, and skip the first one.
148 * The first method doesn't work with the iop3xx adapter driver, on at
149 * least 80219 chips; this works around that bug.
151 * The third method on the other hand doesn't work for the SMBus-only
152 * configurations, so we use the the first method there, stripping off
153 * the extra register in the process.
156 int addr
= RS5C_ADDR(RS5C372_REG_SECS
);
157 int size
= sizeof(rs5c
->buf
) - 1;
159 if (i2c_smbus_read_i2c_block_data(client
, addr
, size
,
160 rs5c
->buf
+ 1) != size
) {
161 dev_warn(&client
->dev
, "can't read registers\n");
165 if ((i2c_transfer(client
->adapter
, msgs
, 1)) != 1) {
166 dev_warn(&client
->dev
, "can't read registers\n");
171 dev_dbg(&client
->dev
,
172 "%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
173 rs5c
->regs
+ 0, rs5c
->regs
[3],
174 rs5c
->regs
+ 4, rs5c
->regs
[7],
175 rs5c
->regs
+ 8, rs5c
->regs
+ 11,
176 rs5c
->regs
[14], rs5c
->regs
[15]);
181 static unsigned rs5c_reg2hr(struct rs5c372
*rs5c
, unsigned reg
)
186 return bcd2bin(reg
& 0x3f);
188 hour
= bcd2bin(reg
& 0x1f);
196 static unsigned rs5c_hr2reg(struct rs5c372
*rs5c
, unsigned hour
)
199 return bin2bcd(hour
);
202 return 0x20 | bin2bcd(hour
- 12);
204 return 0x20 | bin2bcd(12);
207 return bin2bcd(hour
);
210 static int rs5c372_get_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
212 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
213 int status
= rs5c_get_regs(rs5c
);
218 tm
->tm_sec
= bcd2bin(rs5c
->regs
[RS5C372_REG_SECS
] & 0x7f);
219 tm
->tm_min
= bcd2bin(rs5c
->regs
[RS5C372_REG_MINS
] & 0x7f);
220 tm
->tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C372_REG_HOURS
]);
222 tm
->tm_wday
= bcd2bin(rs5c
->regs
[RS5C372_REG_WDAY
] & 0x07);
223 tm
->tm_mday
= bcd2bin(rs5c
->regs
[RS5C372_REG_DAY
] & 0x3f);
225 /* tm->tm_mon is zero-based */
226 tm
->tm_mon
= bcd2bin(rs5c
->regs
[RS5C372_REG_MONTH
] & 0x1f) - 1;
228 /* year is 1900 + tm->tm_year */
229 tm
->tm_year
= bcd2bin(rs5c
->regs
[RS5C372_REG_YEAR
]) + 100;
231 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
232 "mday=%d, mon=%d, year=%d, wday=%d\n",
234 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
235 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
237 /* rtc might need initialization */
238 return rtc_valid_tm(tm
);
241 static int rs5c372_set_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
243 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
244 unsigned char buf
[7];
247 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d "
248 "mday=%d, mon=%d, year=%d, wday=%d\n",
250 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
251 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
253 addr
= RS5C_ADDR(RS5C372_REG_SECS
);
254 buf
[0] = bin2bcd(tm
->tm_sec
);
255 buf
[1] = bin2bcd(tm
->tm_min
);
256 buf
[2] = rs5c_hr2reg(rs5c
, tm
->tm_hour
);
257 buf
[3] = bin2bcd(tm
->tm_wday
);
258 buf
[4] = bin2bcd(tm
->tm_mday
);
259 buf
[5] = bin2bcd(tm
->tm_mon
+ 1);
260 buf
[6] = bin2bcd(tm
->tm_year
- 100);
262 if (i2c_smbus_write_i2c_block_data(client
, addr
, sizeof(buf
), buf
) < 0) {
263 dev_err(&client
->dev
, "%s: write error\n", __func__
);
270 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
274 #if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
279 static int rs5c372_get_trim(struct i2c_client
*client
, int *osc
, int *trim
)
281 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
282 u8 tmp
= rs5c372
->regs
[RS5C372_REG_TRIM
];
285 *osc
= (tmp
& RS5C372_TRIM_XSL
) ? 32000 : 32768;
288 dev_dbg(&client
->dev
, "%s: raw trim=%x\n", __func__
, tmp
);
289 tmp
&= RS5C372_TRIM_MASK
;
294 t
= (~t
| (s8
)0xc0) + 1;
308 static int rs5c372_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
310 return rs5c372_get_datetime(to_i2c_client(dev
), tm
);
313 static int rs5c372_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
315 return rs5c372_set_datetime(to_i2c_client(dev
), tm
);
319 static int rs5c_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
321 struct i2c_client
*client
= to_i2c_client(dev
);
322 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
326 buf
= rs5c
->regs
[RS5C_REG_CTRL1
];
331 status
= rs5c_get_regs(rs5c
);
335 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
337 buf
|= RS5C_CTRL1_AALE
;
339 buf
&= ~RS5C_CTRL1_AALE
;
341 if (i2c_smbus_write_byte_data(client
, addr
, buf
) < 0) {
342 dev_warn(dev
, "can't update alarm\n");
345 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
;
351 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
352 * which only exposes a polled programming interface; and since
353 * these calls map directly to those EFI requests; we don't demand
354 * we have an IRQ for this chip when we go through this API.
356 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
357 * though, managed through RTC_AIE_{ON,OFF} requests.
360 static int rs5c_read_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
362 struct i2c_client
*client
= to_i2c_client(dev
);
363 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
366 status
= rs5c_get_regs(rs5c
);
370 /* report alarm time */
372 t
->time
.tm_min
= bcd2bin(rs5c
->regs
[RS5C_REG_ALARM_A_MIN
] & 0x7f);
373 t
->time
.tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C_REG_ALARM_A_HOURS
]);
376 t
->enabled
= !!(rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
);
377 t
->pending
= !!(rs5c
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_AAFG
);
382 static int rs5c_set_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
384 struct i2c_client
*client
= to_i2c_client(dev
);
385 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
387 unsigned char buf
[3];
389 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
390 if (t
->time
.tm_mday
!= -1
391 || t
->time
.tm_mon
!= -1
392 || t
->time
.tm_year
!= -1)
395 /* REVISIT: round up tm_sec */
397 /* if needed, disable irq (clears pending status) */
398 status
= rs5c_get_regs(rs5c
);
401 if (rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
) {
402 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
403 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] & ~RS5C_CTRL1_AALE
;
404 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0) {
405 dev_dbg(dev
, "can't disable alarm\n");
408 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
412 buf
[0] = bin2bcd(t
->time
.tm_min
);
413 buf
[1] = rs5c_hr2reg(rs5c
, t
->time
.tm_hour
);
414 buf
[2] = 0x7f; /* any/all days */
416 for (i
= 0; i
< sizeof(buf
); i
++) {
417 addr
= RS5C_ADDR(RS5C_REG_ALARM_A_MIN
+ i
);
418 if (i2c_smbus_write_byte_data(client
, addr
, buf
[i
]) < 0) {
419 dev_dbg(dev
, "can't set alarm time\n");
424 /* ... and maybe enable its irq */
426 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
427 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] | RS5C_CTRL1_AALE
;
428 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0)
429 dev_warn(dev
, "can't enable alarm\n");
430 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
436 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
438 static int rs5c372_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
442 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, &trim
);
444 seq_printf(seq
, "crystal\t\t: %d.%03d KHz\n",
445 osc
/ 1000, osc
% 1000);
446 seq_printf(seq
, "trim\t\t: %d\n", trim
);
453 #define rs5c372_rtc_proc NULL
456 static const struct rtc_class_ops rs5c372_rtc_ops
= {
457 .proc
= rs5c372_rtc_proc
,
458 .read_time
= rs5c372_rtc_read_time
,
459 .set_time
= rs5c372_rtc_set_time
,
460 .read_alarm
= rs5c_read_alarm
,
461 .set_alarm
= rs5c_set_alarm
,
462 .alarm_irq_enable
= rs5c_rtc_alarm_irq_enable
,
465 #if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
467 static ssize_t
rs5c372_sysfs_show_trim(struct device
*dev
,
468 struct device_attribute
*attr
, char *buf
)
472 err
= rs5c372_get_trim(to_i2c_client(dev
), NULL
, &trim
);
476 return sprintf(buf
, "%d\n", trim
);
478 static DEVICE_ATTR(trim
, S_IRUGO
, rs5c372_sysfs_show_trim
, NULL
);
480 static ssize_t
rs5c372_sysfs_show_osc(struct device
*dev
,
481 struct device_attribute
*attr
, char *buf
)
485 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, NULL
);
489 return sprintf(buf
, "%d.%03d KHz\n", osc
/ 1000, osc
% 1000);
491 static DEVICE_ATTR(osc
, S_IRUGO
, rs5c372_sysfs_show_osc
, NULL
);
493 static int rs5c_sysfs_register(struct device
*dev
)
497 err
= device_create_file(dev
, &dev_attr_trim
);
500 err
= device_create_file(dev
, &dev_attr_osc
);
502 device_remove_file(dev
, &dev_attr_trim
);
507 static void rs5c_sysfs_unregister(struct device
*dev
)
509 device_remove_file(dev
, &dev_attr_trim
);
510 device_remove_file(dev
, &dev_attr_osc
);
514 static int rs5c_sysfs_register(struct device
*dev
)
519 static void rs5c_sysfs_unregister(struct device
*dev
)
525 static struct i2c_driver rs5c372_driver
;
527 static int rs5c_oscillator_setup(struct rs5c372
*rs5c372
)
529 unsigned char buf
[2];
530 int addr
, i
, ret
= 0;
532 if (rs5c372
->type
== rtc_r2025sd
) {
533 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & R2025_CTRL2_XST
)
535 rs5c372
->regs
[RS5C_REG_CTRL2
] |= R2025_CTRL2_XST
;
537 if (!(rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_XSTP
))
539 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~RS5C_CTRL2_XSTP
;
542 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
543 buf
[0] = rs5c372
->regs
[RS5C_REG_CTRL1
];
544 buf
[1] = rs5c372
->regs
[RS5C_REG_CTRL2
];
547 switch (rs5c372
->type
) {
550 buf
[1] |= RS5C372_CTRL2_24
;
557 buf
[0] |= RV5C387_CTRL1_24
;
565 for (i
= 0; i
< sizeof(buf
); i
++) {
566 addr
= RS5C_ADDR(RS5C_REG_CTRL1
+ i
);
567 ret
= i2c_smbus_write_byte_data(rs5c372
->client
, addr
, buf
[i
]);
568 if (unlikely(ret
< 0))
572 rs5c372
->regs
[RS5C_REG_CTRL1
] = buf
[0];
573 rs5c372
->regs
[RS5C_REG_CTRL2
] = buf
[1];
578 static int rs5c372_probe(struct i2c_client
*client
,
579 const struct i2c_device_id
*id
)
583 struct rs5c372
*rs5c372
;
586 dev_dbg(&client
->dev
, "%s\n", __func__
);
588 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
|
589 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK
)) {
591 * If we don't have any master mode adapter, try breaking
592 * it down in to the barest of capabilities.
594 if (i2c_check_functionality(client
->adapter
,
595 I2C_FUNC_SMBUS_BYTE_DATA
|
596 I2C_FUNC_SMBUS_I2C_BLOCK
))
599 /* Still no good, give up */
605 rs5c372
= devm_kzalloc(&client
->dev
, sizeof(struct rs5c372
),
612 rs5c372
->client
= client
;
613 i2c_set_clientdata(client
, rs5c372
);
614 if (client
->dev
.of_node
)
615 rs5c372
->type
= (enum rtc_type
)
616 of_device_get_match_data(&client
->dev
);
618 rs5c372
->type
= id
->driver_data
;
620 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
621 rs5c372
->regs
= &rs5c372
->buf
[1];
622 rs5c372
->smbus
= smbus_mode
;
624 err
= rs5c_get_regs(rs5c372
);
628 /* clock may be set for am/pm or 24 hr time */
629 switch (rs5c372
->type
) {
632 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
633 * so does periodic irq, except some 327a modes.
635 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C372_CTRL2_24
)
642 if (rs5c372
->regs
[RS5C_REG_CTRL1
] & RV5C387_CTRL1_24
)
644 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
645 * irq, on both 386 and 387
649 dev_err(&client
->dev
, "unknown RTC type\n");
653 /* if the oscillator lost power and no other software (like
654 * the bootloader) set it up, do it here.
656 * The R2025S/D does this a little differently than the other
657 * parts, so we special case that..
659 err
= rs5c_oscillator_setup(rs5c372
);
660 if (unlikely(err
< 0)) {
661 dev_err(&client
->dev
, "setup error\n");
665 if (rs5c372_get_datetime(client
, &tm
) < 0)
666 dev_warn(&client
->dev
, "clock needs to be set\n");
668 dev_info(&client
->dev
, "%s found, %s\n",
669 ({ char *s
; switch (rs5c372
->type
) {
670 case rtc_r2025sd
: s
= "r2025sd"; break;
671 case rtc_r2221tl
: s
= "r2221tl"; break;
672 case rtc_rs5c372a
: s
= "rs5c372a"; break;
673 case rtc_rs5c372b
: s
= "rs5c372b"; break;
674 case rtc_rv5c386
: s
= "rv5c386"; break;
675 case rtc_rv5c387a
: s
= "rv5c387a"; break;
676 default: s
= "chip"; break;
678 rs5c372
->time24
? "24hr" : "am/pm"
681 /* REVISIT use client->irq to register alarm irq ... */
682 rs5c372
->rtc
= devm_rtc_device_register(&client
->dev
,
683 rs5c372_driver
.driver
.name
,
684 &rs5c372_rtc_ops
, THIS_MODULE
);
686 if (IS_ERR(rs5c372
->rtc
)) {
687 err
= PTR_ERR(rs5c372
->rtc
);
691 err
= rs5c_sysfs_register(&client
->dev
);
701 static int rs5c372_remove(struct i2c_client
*client
)
703 rs5c_sysfs_unregister(&client
->dev
);
707 static struct i2c_driver rs5c372_driver
= {
709 .name
= "rtc-rs5c372",
710 .of_match_table
= of_match_ptr(rs5c372_of_match
),
712 .probe
= rs5c372_probe
,
713 .remove
= rs5c372_remove
,
714 .id_table
= rs5c372_id
,
717 module_i2c_driver(rs5c372_driver
);
720 "Pavel Mironchik <pmironchik@optifacio.net>, "
721 "Alessandro Zummo <a.zummo@towertech.it>, "
722 "Paul Mundt <lethal@linux-sh.org>");
723 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
724 MODULE_LICENSE("GPL");