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_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
212 struct i2c_client
*client
= to_i2c_client(dev
);
213 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
214 int status
= rs5c_get_regs(rs5c
);
219 tm
->tm_sec
= bcd2bin(rs5c
->regs
[RS5C372_REG_SECS
] & 0x7f);
220 tm
->tm_min
= bcd2bin(rs5c
->regs
[RS5C372_REG_MINS
] & 0x7f);
221 tm
->tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C372_REG_HOURS
]);
223 tm
->tm_wday
= bcd2bin(rs5c
->regs
[RS5C372_REG_WDAY
] & 0x07);
224 tm
->tm_mday
= bcd2bin(rs5c
->regs
[RS5C372_REG_DAY
] & 0x3f);
226 /* tm->tm_mon is zero-based */
227 tm
->tm_mon
= bcd2bin(rs5c
->regs
[RS5C372_REG_MONTH
] & 0x1f) - 1;
229 /* year is 1900 + tm->tm_year */
230 tm
->tm_year
= bcd2bin(rs5c
->regs
[RS5C372_REG_YEAR
]) + 100;
232 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
233 "mday=%d, mon=%d, year=%d, wday=%d\n",
235 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
236 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
241 static int rs5c372_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
243 struct i2c_client
*client
= to_i2c_client(dev
);
244 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
245 unsigned char buf
[7];
248 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d "
249 "mday=%d, mon=%d, year=%d, wday=%d\n",
251 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
252 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
254 addr
= RS5C_ADDR(RS5C372_REG_SECS
);
255 buf
[0] = bin2bcd(tm
->tm_sec
);
256 buf
[1] = bin2bcd(tm
->tm_min
);
257 buf
[2] = rs5c_hr2reg(rs5c
, tm
->tm_hour
);
258 buf
[3] = bin2bcd(tm
->tm_wday
);
259 buf
[4] = bin2bcd(tm
->tm_mday
);
260 buf
[5] = bin2bcd(tm
->tm_mon
+ 1);
261 buf
[6] = bin2bcd(tm
->tm_year
- 100);
263 if (i2c_smbus_write_i2c_block_data(client
, addr
, sizeof(buf
), buf
) < 0) {
264 dev_err(&client
->dev
, "%s: write error\n", __func__
);
271 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
275 #if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
280 static int rs5c372_get_trim(struct i2c_client
*client
, int *osc
, int *trim
)
282 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
283 u8 tmp
= rs5c372
->regs
[RS5C372_REG_TRIM
];
286 *osc
= (tmp
& RS5C372_TRIM_XSL
) ? 32000 : 32768;
289 dev_dbg(&client
->dev
, "%s: raw trim=%x\n", __func__
, tmp
);
290 tmp
&= RS5C372_TRIM_MASK
;
295 t
= (~t
| (s8
)0xc0) + 1;
309 static int rs5c_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
311 struct i2c_client
*client
= to_i2c_client(dev
);
312 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
316 buf
= rs5c
->regs
[RS5C_REG_CTRL1
];
321 status
= rs5c_get_regs(rs5c
);
325 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
327 buf
|= RS5C_CTRL1_AALE
;
329 buf
&= ~RS5C_CTRL1_AALE
;
331 if (i2c_smbus_write_byte_data(client
, addr
, buf
) < 0) {
332 dev_warn(dev
, "can't update alarm\n");
335 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
;
341 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
342 * which only exposes a polled programming interface; and since
343 * these calls map directly to those EFI requests; we don't demand
344 * we have an IRQ for this chip when we go through this API.
346 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
347 * though, managed through RTC_AIE_{ON,OFF} requests.
350 static int rs5c_read_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
352 struct i2c_client
*client
= to_i2c_client(dev
);
353 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
356 status
= rs5c_get_regs(rs5c
);
360 /* report alarm time */
362 t
->time
.tm_min
= bcd2bin(rs5c
->regs
[RS5C_REG_ALARM_A_MIN
] & 0x7f);
363 t
->time
.tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C_REG_ALARM_A_HOURS
]);
366 t
->enabled
= !!(rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
);
367 t
->pending
= !!(rs5c
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_AAFG
);
372 static int rs5c_set_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
374 struct i2c_client
*client
= to_i2c_client(dev
);
375 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
377 unsigned char buf
[3];
379 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
380 if (t
->time
.tm_mday
!= -1
381 || t
->time
.tm_mon
!= -1
382 || t
->time
.tm_year
!= -1)
385 /* REVISIT: round up tm_sec */
387 /* if needed, disable irq (clears pending status) */
388 status
= rs5c_get_regs(rs5c
);
391 if (rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
) {
392 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
393 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] & ~RS5C_CTRL1_AALE
;
394 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0) {
395 dev_dbg(dev
, "can't disable alarm\n");
398 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
402 buf
[0] = bin2bcd(t
->time
.tm_min
);
403 buf
[1] = rs5c_hr2reg(rs5c
, t
->time
.tm_hour
);
404 buf
[2] = 0x7f; /* any/all days */
406 for (i
= 0; i
< sizeof(buf
); i
++) {
407 addr
= RS5C_ADDR(RS5C_REG_ALARM_A_MIN
+ i
);
408 if (i2c_smbus_write_byte_data(client
, addr
, buf
[i
]) < 0) {
409 dev_dbg(dev
, "can't set alarm time\n");
414 /* ... and maybe enable its irq */
416 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
417 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] | RS5C_CTRL1_AALE
;
418 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0)
419 dev_warn(dev
, "can't enable alarm\n");
420 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
426 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
428 static int rs5c372_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
432 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, &trim
);
434 seq_printf(seq
, "crystal\t\t: %d.%03d KHz\n",
435 osc
/ 1000, osc
% 1000);
436 seq_printf(seq
, "trim\t\t: %d\n", trim
);
443 #define rs5c372_rtc_proc NULL
446 static const struct rtc_class_ops rs5c372_rtc_ops
= {
447 .proc
= rs5c372_rtc_proc
,
448 .read_time
= rs5c372_rtc_read_time
,
449 .set_time
= rs5c372_rtc_set_time
,
450 .read_alarm
= rs5c_read_alarm
,
451 .set_alarm
= rs5c_set_alarm
,
452 .alarm_irq_enable
= rs5c_rtc_alarm_irq_enable
,
455 #if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
457 static ssize_t
rs5c372_sysfs_show_trim(struct device
*dev
,
458 struct device_attribute
*attr
, char *buf
)
462 err
= rs5c372_get_trim(to_i2c_client(dev
), NULL
, &trim
);
466 return sprintf(buf
, "%d\n", trim
);
468 static DEVICE_ATTR(trim
, S_IRUGO
, rs5c372_sysfs_show_trim
, NULL
);
470 static ssize_t
rs5c372_sysfs_show_osc(struct device
*dev
,
471 struct device_attribute
*attr
, char *buf
)
475 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, NULL
);
479 return sprintf(buf
, "%d.%03d KHz\n", osc
/ 1000, osc
% 1000);
481 static DEVICE_ATTR(osc
, S_IRUGO
, rs5c372_sysfs_show_osc
, NULL
);
483 static int rs5c_sysfs_register(struct device
*dev
)
487 err
= device_create_file(dev
, &dev_attr_trim
);
490 err
= device_create_file(dev
, &dev_attr_osc
);
492 device_remove_file(dev
, &dev_attr_trim
);
497 static void rs5c_sysfs_unregister(struct device
*dev
)
499 device_remove_file(dev
, &dev_attr_trim
);
500 device_remove_file(dev
, &dev_attr_osc
);
504 static int rs5c_sysfs_register(struct device
*dev
)
509 static void rs5c_sysfs_unregister(struct device
*dev
)
515 static struct i2c_driver rs5c372_driver
;
517 static int rs5c_oscillator_setup(struct rs5c372
*rs5c372
)
519 unsigned char buf
[2];
520 int addr
, i
, ret
= 0;
522 if (rs5c372
->type
== rtc_r2025sd
) {
523 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & R2025_CTRL2_XST
)
525 rs5c372
->regs
[RS5C_REG_CTRL2
] |= R2025_CTRL2_XST
;
527 if (!(rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_XSTP
))
529 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~RS5C_CTRL2_XSTP
;
532 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
533 buf
[0] = rs5c372
->regs
[RS5C_REG_CTRL1
];
534 buf
[1] = rs5c372
->regs
[RS5C_REG_CTRL2
];
537 switch (rs5c372
->type
) {
540 buf
[1] |= RS5C372_CTRL2_24
;
547 buf
[0] |= RV5C387_CTRL1_24
;
555 for (i
= 0; i
< sizeof(buf
); i
++) {
556 addr
= RS5C_ADDR(RS5C_REG_CTRL1
+ i
);
557 ret
= i2c_smbus_write_byte_data(rs5c372
->client
, addr
, buf
[i
]);
558 if (unlikely(ret
< 0))
562 rs5c372
->regs
[RS5C_REG_CTRL1
] = buf
[0];
563 rs5c372
->regs
[RS5C_REG_CTRL2
] = buf
[1];
568 static int rs5c372_probe(struct i2c_client
*client
,
569 const struct i2c_device_id
*id
)
573 struct rs5c372
*rs5c372
;
575 dev_dbg(&client
->dev
, "%s\n", __func__
);
577 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
|
578 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK
)) {
580 * If we don't have any master mode adapter, try breaking
581 * it down in to the barest of capabilities.
583 if (i2c_check_functionality(client
->adapter
,
584 I2C_FUNC_SMBUS_BYTE_DATA
|
585 I2C_FUNC_SMBUS_I2C_BLOCK
))
588 /* Still no good, give up */
594 rs5c372
= devm_kzalloc(&client
->dev
, sizeof(struct rs5c372
),
601 rs5c372
->client
= client
;
602 i2c_set_clientdata(client
, rs5c372
);
603 if (client
->dev
.of_node
)
604 rs5c372
->type
= (enum rtc_type
)
605 of_device_get_match_data(&client
->dev
);
607 rs5c372
->type
= id
->driver_data
;
609 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
610 rs5c372
->regs
= &rs5c372
->buf
[1];
611 rs5c372
->smbus
= smbus_mode
;
613 err
= rs5c_get_regs(rs5c372
);
617 /* clock may be set for am/pm or 24 hr time */
618 switch (rs5c372
->type
) {
621 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
622 * so does periodic irq, except some 327a modes.
624 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C372_CTRL2_24
)
631 if (rs5c372
->regs
[RS5C_REG_CTRL1
] & RV5C387_CTRL1_24
)
633 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
634 * irq, on both 386 and 387
638 dev_err(&client
->dev
, "unknown RTC type\n");
642 /* if the oscillator lost power and no other software (like
643 * the bootloader) set it up, do it here.
645 * The R2025S/D does this a little differently than the other
646 * parts, so we special case that..
648 err
= rs5c_oscillator_setup(rs5c372
);
649 if (unlikely(err
< 0)) {
650 dev_err(&client
->dev
, "setup error\n");
654 dev_info(&client
->dev
, "%s found, %s\n",
655 ({ char *s
; switch (rs5c372
->type
) {
656 case rtc_r2025sd
: s
= "r2025sd"; break;
657 case rtc_r2221tl
: s
= "r2221tl"; break;
658 case rtc_rs5c372a
: s
= "rs5c372a"; break;
659 case rtc_rs5c372b
: s
= "rs5c372b"; break;
660 case rtc_rv5c386
: s
= "rv5c386"; break;
661 case rtc_rv5c387a
: s
= "rv5c387a"; break;
662 default: s
= "chip"; break;
664 rs5c372
->time24
? "24hr" : "am/pm"
667 /* REVISIT use client->irq to register alarm irq ... */
668 rs5c372
->rtc
= devm_rtc_device_register(&client
->dev
,
669 rs5c372_driver
.driver
.name
,
670 &rs5c372_rtc_ops
, THIS_MODULE
);
672 if (IS_ERR(rs5c372
->rtc
)) {
673 err
= PTR_ERR(rs5c372
->rtc
);
677 err
= rs5c_sysfs_register(&client
->dev
);
687 static int rs5c372_remove(struct i2c_client
*client
)
689 rs5c_sysfs_unregister(&client
->dev
);
693 static struct i2c_driver rs5c372_driver
= {
695 .name
= "rtc-rs5c372",
696 .of_match_table
= of_match_ptr(rs5c372_of_match
),
698 .probe
= rs5c372_probe
,
699 .remove
= rs5c372_remove
,
700 .id_table
= rs5c372_id
,
703 module_i2c_driver(rs5c372_driver
);
706 "Pavel Mironchik <pmironchik@optifacio.net>, "
707 "Alessandro Zummo <a.zummo@towertech.it>, "
708 "Paul Mundt <lethal@linux-sh.org>");
709 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
710 MODULE_LICENSE("GPL");