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>
19 #define DRV_VERSION "0.6"
23 * Ricoh has a family of I2C based RTCs, which differ only slightly from
24 * each other. Differences center on pinout (e.g. how many interrupts,
25 * output clock, etc) and how the control registers are used. The '372
26 * is significant only because that's the one this driver first supported.
28 #define RS5C372_REG_SECS 0
29 #define RS5C372_REG_MINS 1
30 #define RS5C372_REG_HOURS 2
31 #define RS5C372_REG_WDAY 3
32 #define RS5C372_REG_DAY 4
33 #define RS5C372_REG_MONTH 5
34 #define RS5C372_REG_YEAR 6
35 #define RS5C372_REG_TRIM 7
36 # define RS5C372_TRIM_XSL 0x80
37 # define RS5C372_TRIM_MASK 0x7F
39 #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
40 #define RS5C_REG_ALARM_A_HOURS 9
41 #define RS5C_REG_ALARM_A_WDAY 10
43 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
44 #define RS5C_REG_ALARM_B_HOURS 12
45 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
47 #define RS5C_REG_CTRL1 14
48 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
49 # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
50 # define RV5C387_CTRL1_24 (1 << 5)
51 # define RS5C372A_CTRL1_SL1 (1 << 5)
52 # define RS5C_CTRL1_CT_MASK (7 << 0)
53 # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
54 # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
55 #define RS5C_REG_CTRL2 15
56 # define RS5C372_CTRL2_24 (1 << 5)
57 # define R2025_CTRL2_XST (1 << 5)
58 # define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2025S/D */
59 # define RS5C_CTRL2_CTFG (1 << 2)
60 # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
61 # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
64 /* to read (style 1) or write registers starting at R */
65 #define RS5C_ADDR(R) (((R) << 4) | 0)
78 static const struct i2c_device_id rs5c372_id
[] = {
79 { "r2025sd", rtc_r2025sd
},
80 { "r2221tl", rtc_r2221tl
},
81 { "rs5c372a", rtc_rs5c372a
},
82 { "rs5c372b", rtc_rs5c372b
},
83 { "rv5c386", rtc_rv5c386
},
84 { "rv5c387a", rtc_rv5c387a
},
87 MODULE_DEVICE_TABLE(i2c
, rs5c372_id
);
89 /* REVISIT: this assumes that:
90 * - we're in the 21st century, so it's safe to ignore the century
91 * bit for rv5c38[67] (REG_MONTH bit 7);
92 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
95 struct i2c_client
*client
;
96 struct rtc_device
*rtc
;
105 static int rs5c_get_regs(struct rs5c372
*rs5c
)
107 struct i2c_client
*client
= rs5c
->client
;
108 struct i2c_msg msgs
[] = {
110 .addr
= client
->addr
,
112 .len
= sizeof(rs5c
->buf
),
117 /* This implements the third reading method from the datasheet, using
118 * an internal address that's reset after each transaction (by STOP)
119 * to 0x0f ... so we read extra registers, and skip the first one.
121 * The first method doesn't work with the iop3xx adapter driver, on at
122 * least 80219 chips; this works around that bug.
124 * The third method on the other hand doesn't work for the SMBus-only
125 * configurations, so we use the the first method there, stripping off
126 * the extra register in the process.
129 int addr
= RS5C_ADDR(RS5C372_REG_SECS
);
130 int size
= sizeof(rs5c
->buf
) - 1;
132 if (i2c_smbus_read_i2c_block_data(client
, addr
, size
,
133 rs5c
->buf
+ 1) != size
) {
134 dev_warn(&client
->dev
, "can't read registers\n");
138 if ((i2c_transfer(client
->adapter
, msgs
, 1)) != 1) {
139 dev_warn(&client
->dev
, "can't read registers\n");
144 dev_dbg(&client
->dev
,
145 "%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
146 rs5c
->regs
+ 0, rs5c
->regs
[3],
147 rs5c
->regs
+ 4, rs5c
->regs
[7],
148 rs5c
->regs
+ 8, rs5c
->regs
+ 11,
149 rs5c
->regs
[14], rs5c
->regs
[15]);
154 static unsigned rs5c_reg2hr(struct rs5c372
*rs5c
, unsigned reg
)
159 return bcd2bin(reg
& 0x3f);
161 hour
= bcd2bin(reg
& 0x1f);
169 static unsigned rs5c_hr2reg(struct rs5c372
*rs5c
, unsigned hour
)
172 return bin2bcd(hour
);
175 return 0x20 | bin2bcd(hour
- 12);
177 return 0x20 | bin2bcd(12);
180 return bin2bcd(hour
);
183 static int rs5c372_get_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
185 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
186 int status
= rs5c_get_regs(rs5c
);
191 tm
->tm_sec
= bcd2bin(rs5c
->regs
[RS5C372_REG_SECS
] & 0x7f);
192 tm
->tm_min
= bcd2bin(rs5c
->regs
[RS5C372_REG_MINS
] & 0x7f);
193 tm
->tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C372_REG_HOURS
]);
195 tm
->tm_wday
= bcd2bin(rs5c
->regs
[RS5C372_REG_WDAY
] & 0x07);
196 tm
->tm_mday
= bcd2bin(rs5c
->regs
[RS5C372_REG_DAY
] & 0x3f);
198 /* tm->tm_mon is zero-based */
199 tm
->tm_mon
= bcd2bin(rs5c
->regs
[RS5C372_REG_MONTH
] & 0x1f) - 1;
201 /* year is 1900 + tm->tm_year */
202 tm
->tm_year
= bcd2bin(rs5c
->regs
[RS5C372_REG_YEAR
]) + 100;
204 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
205 "mday=%d, mon=%d, year=%d, wday=%d\n",
207 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
208 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
210 /* rtc might need initialization */
211 return rtc_valid_tm(tm
);
214 static int rs5c372_set_datetime(struct i2c_client
*client
, struct rtc_time
*tm
)
216 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
217 unsigned char buf
[7];
220 dev_dbg(&client
->dev
, "%s: tm is secs=%d, mins=%d, hours=%d "
221 "mday=%d, mon=%d, year=%d, wday=%d\n",
223 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
224 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
, tm
->tm_wday
);
226 addr
= RS5C_ADDR(RS5C372_REG_SECS
);
227 buf
[0] = bin2bcd(tm
->tm_sec
);
228 buf
[1] = bin2bcd(tm
->tm_min
);
229 buf
[2] = rs5c_hr2reg(rs5c
, tm
->tm_hour
);
230 buf
[3] = bin2bcd(tm
->tm_wday
);
231 buf
[4] = bin2bcd(tm
->tm_mday
);
232 buf
[5] = bin2bcd(tm
->tm_mon
+ 1);
233 buf
[6] = bin2bcd(tm
->tm_year
- 100);
235 if (i2c_smbus_write_i2c_block_data(client
, addr
, sizeof(buf
), buf
) < 0) {
236 dev_err(&client
->dev
, "%s: write error\n", __func__
);
243 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
247 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
252 static int rs5c372_get_trim(struct i2c_client
*client
, int *osc
, int *trim
)
254 struct rs5c372
*rs5c372
= i2c_get_clientdata(client
);
255 u8 tmp
= rs5c372
->regs
[RS5C372_REG_TRIM
];
258 *osc
= (tmp
& RS5C372_TRIM_XSL
) ? 32000 : 32768;
261 dev_dbg(&client
->dev
, "%s: raw trim=%x\n", __func__
, tmp
);
262 tmp
&= RS5C372_TRIM_MASK
;
267 t
= (~t
| (s8
)0xc0) + 1;
281 static int rs5c372_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
283 return rs5c372_get_datetime(to_i2c_client(dev
), tm
);
286 static int rs5c372_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
288 return rs5c372_set_datetime(to_i2c_client(dev
), tm
);
292 static int rs5c_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
294 struct i2c_client
*client
= to_i2c_client(dev
);
295 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
299 buf
= rs5c
->regs
[RS5C_REG_CTRL1
];
304 status
= rs5c_get_regs(rs5c
);
308 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
310 buf
|= RS5C_CTRL1_AALE
;
312 buf
&= ~RS5C_CTRL1_AALE
;
314 if (i2c_smbus_write_byte_data(client
, addr
, buf
) < 0) {
315 dev_warn(dev
, "can't update alarm\n");
318 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
;
324 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
325 * which only exposes a polled programming interface; and since
326 * these calls map directly to those EFI requests; we don't demand
327 * we have an IRQ for this chip when we go through this API.
329 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
330 * though, managed through RTC_AIE_{ON,OFF} requests.
333 static int rs5c_read_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
335 struct i2c_client
*client
= to_i2c_client(dev
);
336 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
339 status
= rs5c_get_regs(rs5c
);
343 /* report alarm time */
345 t
->time
.tm_min
= bcd2bin(rs5c
->regs
[RS5C_REG_ALARM_A_MIN
] & 0x7f);
346 t
->time
.tm_hour
= rs5c_reg2hr(rs5c
, rs5c
->regs
[RS5C_REG_ALARM_A_HOURS
]);
347 t
->time
.tm_mday
= -1;
349 t
->time
.tm_year
= -1;
350 t
->time
.tm_wday
= -1;
351 t
->time
.tm_yday
= -1;
352 t
->time
.tm_isdst
= -1;
355 t
->enabled
= !!(rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
);
356 t
->pending
= !!(rs5c
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_AAFG
);
361 static int rs5c_set_alarm(struct device
*dev
, struct rtc_wkalrm
*t
)
363 struct i2c_client
*client
= to_i2c_client(dev
);
364 struct rs5c372
*rs5c
= i2c_get_clientdata(client
);
366 unsigned char buf
[3];
368 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
369 if (t
->time
.tm_mday
!= -1
370 || t
->time
.tm_mon
!= -1
371 || t
->time
.tm_year
!= -1)
374 /* REVISIT: round up tm_sec */
376 /* if needed, disable irq (clears pending status) */
377 status
= rs5c_get_regs(rs5c
);
380 if (rs5c
->regs
[RS5C_REG_CTRL1
] & RS5C_CTRL1_AALE
) {
381 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
382 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] & ~RS5C_CTRL1_AALE
;
383 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0) {
384 dev_dbg(dev
, "can't disable alarm\n");
387 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
391 buf
[0] = bin2bcd(t
->time
.tm_min
);
392 buf
[1] = rs5c_hr2reg(rs5c
, t
->time
.tm_hour
);
393 buf
[2] = 0x7f; /* any/all days */
395 for (i
= 0; i
< sizeof(buf
); i
++) {
396 addr
= RS5C_ADDR(RS5C_REG_ALARM_A_MIN
+ i
);
397 if (i2c_smbus_write_byte_data(client
, addr
, buf
[i
]) < 0) {
398 dev_dbg(dev
, "can't set alarm time\n");
403 /* ... and maybe enable its irq */
405 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
406 buf
[0] = rs5c
->regs
[RS5C_REG_CTRL1
] | RS5C_CTRL1_AALE
;
407 if (i2c_smbus_write_byte_data(client
, addr
, buf
[0]) < 0)
408 dev_warn(dev
, "can't enable alarm\n");
409 rs5c
->regs
[RS5C_REG_CTRL1
] = buf
[0];
415 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
417 static int rs5c372_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
421 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, &trim
);
423 seq_printf(seq
, "crystal\t\t: %d.%03d KHz\n",
424 osc
/ 1000, osc
% 1000);
425 seq_printf(seq
, "trim\t\t: %d\n", trim
);
432 #define rs5c372_rtc_proc NULL
435 static const struct rtc_class_ops rs5c372_rtc_ops
= {
436 .proc
= rs5c372_rtc_proc
,
437 .read_time
= rs5c372_rtc_read_time
,
438 .set_time
= rs5c372_rtc_set_time
,
439 .read_alarm
= rs5c_read_alarm
,
440 .set_alarm
= rs5c_set_alarm
,
441 .alarm_irq_enable
= rs5c_rtc_alarm_irq_enable
,
444 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
446 static ssize_t
rs5c372_sysfs_show_trim(struct device
*dev
,
447 struct device_attribute
*attr
, char *buf
)
451 err
= rs5c372_get_trim(to_i2c_client(dev
), NULL
, &trim
);
455 return sprintf(buf
, "%d\n", trim
);
457 static DEVICE_ATTR(trim
, S_IRUGO
, rs5c372_sysfs_show_trim
, NULL
);
459 static ssize_t
rs5c372_sysfs_show_osc(struct device
*dev
,
460 struct device_attribute
*attr
, char *buf
)
464 err
= rs5c372_get_trim(to_i2c_client(dev
), &osc
, NULL
);
468 return sprintf(buf
, "%d.%03d KHz\n", osc
/ 1000, osc
% 1000);
470 static DEVICE_ATTR(osc
, S_IRUGO
, rs5c372_sysfs_show_osc
, NULL
);
472 static int rs5c_sysfs_register(struct device
*dev
)
476 err
= device_create_file(dev
, &dev_attr_trim
);
479 err
= device_create_file(dev
, &dev_attr_osc
);
481 device_remove_file(dev
, &dev_attr_trim
);
486 static void rs5c_sysfs_unregister(struct device
*dev
)
488 device_remove_file(dev
, &dev_attr_trim
);
489 device_remove_file(dev
, &dev_attr_osc
);
493 static int rs5c_sysfs_register(struct device
*dev
)
498 static void rs5c_sysfs_unregister(struct device
*dev
)
504 static struct i2c_driver rs5c372_driver
;
506 static int rs5c_oscillator_setup(struct rs5c372
*rs5c372
)
508 unsigned char buf
[2];
509 int addr
, i
, ret
= 0;
511 if (rs5c372
->type
== rtc_r2025sd
) {
512 if (!(rs5c372
->regs
[RS5C_REG_CTRL2
] & R2025_CTRL2_XST
))
514 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~R2025_CTRL2_XST
;
516 if (!(rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C_CTRL2_XSTP
))
518 rs5c372
->regs
[RS5C_REG_CTRL2
] &= ~RS5C_CTRL2_XSTP
;
521 addr
= RS5C_ADDR(RS5C_REG_CTRL1
);
522 buf
[0] = rs5c372
->regs
[RS5C_REG_CTRL1
];
523 buf
[1] = rs5c372
->regs
[RS5C_REG_CTRL2
];
526 switch (rs5c372
->type
) {
529 buf
[1] |= RS5C372_CTRL2_24
;
536 buf
[0] |= RV5C387_CTRL1_24
;
544 for (i
= 0; i
< sizeof(buf
); i
++) {
545 addr
= RS5C_ADDR(RS5C_REG_CTRL1
+ i
);
546 ret
= i2c_smbus_write_byte_data(rs5c372
->client
, addr
, buf
[i
]);
547 if (unlikely(ret
< 0))
551 rs5c372
->regs
[RS5C_REG_CTRL1
] = buf
[0];
552 rs5c372
->regs
[RS5C_REG_CTRL2
] = buf
[1];
557 static int rs5c372_probe(struct i2c_client
*client
,
558 const struct i2c_device_id
*id
)
562 struct rs5c372
*rs5c372
;
565 dev_dbg(&client
->dev
, "%s\n", __func__
);
567 if (!i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
|
568 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK
)) {
570 * If we don't have any master mode adapter, try breaking
571 * it down in to the barest of capabilities.
573 if (i2c_check_functionality(client
->adapter
,
574 I2C_FUNC_SMBUS_BYTE_DATA
|
575 I2C_FUNC_SMBUS_I2C_BLOCK
))
578 /* Still no good, give up */
584 rs5c372
= devm_kzalloc(&client
->dev
, sizeof(struct rs5c372
),
591 rs5c372
->client
= client
;
592 i2c_set_clientdata(client
, rs5c372
);
593 rs5c372
->type
= id
->driver_data
;
595 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
596 rs5c372
->regs
= &rs5c372
->buf
[1];
597 rs5c372
->smbus
= smbus_mode
;
599 err
= rs5c_get_regs(rs5c372
);
603 /* clock may be set for am/pm or 24 hr time */
604 switch (rs5c372
->type
) {
607 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
608 * so does periodic irq, except some 327a modes.
610 if (rs5c372
->regs
[RS5C_REG_CTRL2
] & RS5C372_CTRL2_24
)
617 if (rs5c372
->regs
[RS5C_REG_CTRL1
] & RV5C387_CTRL1_24
)
619 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
620 * irq, on both 386 and 387
624 dev_err(&client
->dev
, "unknown RTC type\n");
628 /* if the oscillator lost power and no other software (like
629 * the bootloader) set it up, do it here.
631 * The R2025S/D does this a little differently than the other
632 * parts, so we special case that..
634 err
= rs5c_oscillator_setup(rs5c372
);
635 if (unlikely(err
< 0)) {
636 dev_err(&client
->dev
, "setup error\n");
640 if (rs5c372_get_datetime(client
, &tm
) < 0)
641 dev_warn(&client
->dev
, "clock needs to be set\n");
643 dev_info(&client
->dev
, "%s found, %s, driver version " DRV_VERSION
"\n",
644 ({ char *s
; switch (rs5c372
->type
) {
645 case rtc_r2025sd
: s
= "r2025sd"; break;
646 case rtc_r2221tl
: s
= "r2221tl"; break;
647 case rtc_rs5c372a
: s
= "rs5c372a"; break;
648 case rtc_rs5c372b
: s
= "rs5c372b"; break;
649 case rtc_rv5c386
: s
= "rv5c386"; break;
650 case rtc_rv5c387a
: s
= "rv5c387a"; break;
651 default: s
= "chip"; break;
653 rs5c372
->time24
? "24hr" : "am/pm"
656 /* REVISIT use client->irq to register alarm irq ... */
657 rs5c372
->rtc
= devm_rtc_device_register(&client
->dev
,
658 rs5c372_driver
.driver
.name
,
659 &rs5c372_rtc_ops
, THIS_MODULE
);
661 if (IS_ERR(rs5c372
->rtc
)) {
662 err
= PTR_ERR(rs5c372
->rtc
);
666 err
= rs5c_sysfs_register(&client
->dev
);
676 static int rs5c372_remove(struct i2c_client
*client
)
678 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 module_i2c_driver(rs5c372_driver
);
694 "Pavel Mironchik <pmironchik@optifacio.net>, "
695 "Alessandro Zummo <a.zummo@towertech.it>, "
696 "Paul Mundt <lethal@linux-sh.org>");
697 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
698 MODULE_LICENSE("GPL");
699 MODULE_VERSION(DRV_VERSION
);