4 * Copyright (c) 2007 Wind River Systems, Inc.
6 * Author: Mark Zhan <rongkai.zhan@windriver.com>
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/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
17 #include <linux/device.h>
18 #include <linux/platform_device.h>
19 #include <linux/rtc.h>
20 #include <linux/rtc/m48t59.h>
21 #include <linux/bcd.h>
22 #include <linux/slab.h>
28 #define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
29 #define M48T59_WRITE(val, reg) \
30 (pdata->write_byte(dev, pdata->offset + reg, val))
32 #define M48T59_SET_BITS(mask, reg) \
33 M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
34 #define M48T59_CLEAR_BITS(mask, reg) \
35 M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))
37 struct m48t59_private
{
40 struct rtc_device
*rtc
;
41 spinlock_t lock
; /* serialize the NVRAM and RTC access */
45 * This is the generic access method when the chip is memory-mapped
48 m48t59_mem_writeb(struct device
*dev
, u32 ofs
, u8 val
)
50 struct platform_device
*pdev
= to_platform_device(dev
);
51 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
53 writeb(val
, m48t59
->ioaddr
+ofs
);
57 m48t59_mem_readb(struct device
*dev
, u32 ofs
)
59 struct platform_device
*pdev
= to_platform_device(dev
);
60 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
62 return readb(m48t59
->ioaddr
+ofs
);
66 * NOTE: M48T59 only uses BCD mode
68 static int m48t59_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
70 struct platform_device
*pdev
= to_platform_device(dev
);
71 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
72 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
76 spin_lock_irqsave(&m48t59
->lock
, flags
);
77 /* Issue the READ command */
78 M48T59_SET_BITS(M48T59_CNTL_READ
, M48T59_CNTL
);
80 tm
->tm_year
= bcd2bin(M48T59_READ(M48T59_YEAR
));
82 tm
->tm_mon
= bcd2bin(M48T59_READ(M48T59_MONTH
)) - 1;
83 tm
->tm_mday
= bcd2bin(M48T59_READ(M48T59_MDAY
));
85 val
= M48T59_READ(M48T59_WDAY
);
86 if ((pdata
->type
== M48T59RTC_TYPE_M48T59
) &&
87 (val
& M48T59_WDAY_CEB
) && (val
& M48T59_WDAY_CB
)) {
88 dev_dbg(dev
, "Century bit is enabled\n");
89 tm
->tm_year
+= 100; /* one century */
92 /* Sun SPARC machines count years since 1968 */
96 tm
->tm_wday
= bcd2bin(val
& 0x07);
97 tm
->tm_hour
= bcd2bin(M48T59_READ(M48T59_HOUR
) & 0x3F);
98 tm
->tm_min
= bcd2bin(M48T59_READ(M48T59_MIN
) & 0x7F);
99 tm
->tm_sec
= bcd2bin(M48T59_READ(M48T59_SEC
) & 0x7F);
101 /* Clear the READ bit */
102 M48T59_CLEAR_BITS(M48T59_CNTL_READ
, M48T59_CNTL
);
103 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
105 dev_dbg(dev
, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
106 tm
->tm_year
+ 1900, tm
->tm_mon
, tm
->tm_mday
,
107 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
108 return rtc_valid_tm(tm
);
111 static int m48t59_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
113 struct platform_device
*pdev
= to_platform_device(dev
);
114 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
115 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
118 int year
= tm
->tm_year
;
121 /* Sun SPARC machines count years since 1968 */
125 dev_dbg(dev
, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
126 year
+ 1900, tm
->tm_mon
, tm
->tm_mday
,
127 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
132 spin_lock_irqsave(&m48t59
->lock
, flags
);
133 /* Issue the WRITE command */
134 M48T59_SET_BITS(M48T59_CNTL_WRITE
, M48T59_CNTL
);
136 M48T59_WRITE((bin2bcd(tm
->tm_sec
) & 0x7F), M48T59_SEC
);
137 M48T59_WRITE((bin2bcd(tm
->tm_min
) & 0x7F), M48T59_MIN
);
138 M48T59_WRITE((bin2bcd(tm
->tm_hour
) & 0x3F), M48T59_HOUR
);
139 M48T59_WRITE((bin2bcd(tm
->tm_mday
) & 0x3F), M48T59_MDAY
);
141 M48T59_WRITE((bin2bcd(tm
->tm_mon
+ 1) & 0x1F), M48T59_MONTH
);
142 M48T59_WRITE(bin2bcd(year
% 100), M48T59_YEAR
);
144 if (pdata
->type
== M48T59RTC_TYPE_M48T59
&& (year
/ 100))
145 val
= (M48T59_WDAY_CEB
| M48T59_WDAY_CB
);
146 val
|= (bin2bcd(tm
->tm_wday
) & 0x07);
147 M48T59_WRITE(val
, M48T59_WDAY
);
149 /* Clear the WRITE bit */
150 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE
, M48T59_CNTL
);
151 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
156 * Read alarm time and date in RTC
158 static int m48t59_rtc_readalarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
160 struct platform_device
*pdev
= to_platform_device(dev
);
161 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
162 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
163 struct rtc_time
*tm
= &alrm
->time
;
167 /* If no irq, we don't support ALARM */
168 if (m48t59
->irq
== NO_IRQ
)
171 spin_lock_irqsave(&m48t59
->lock
, flags
);
172 /* Issue the READ command */
173 M48T59_SET_BITS(M48T59_CNTL_READ
, M48T59_CNTL
);
175 tm
->tm_year
= bcd2bin(M48T59_READ(M48T59_YEAR
));
177 /* Sun SPARC machines count years since 1968 */
181 tm
->tm_mon
= bcd2bin(M48T59_READ(M48T59_MONTH
)) - 1;
183 val
= M48T59_READ(M48T59_WDAY
);
184 if ((val
& M48T59_WDAY_CEB
) && (val
& M48T59_WDAY_CB
))
185 tm
->tm_year
+= 100; /* one century */
187 tm
->tm_mday
= bcd2bin(M48T59_READ(M48T59_ALARM_DATE
));
188 tm
->tm_hour
= bcd2bin(M48T59_READ(M48T59_ALARM_HOUR
));
189 tm
->tm_min
= bcd2bin(M48T59_READ(M48T59_ALARM_MIN
));
190 tm
->tm_sec
= bcd2bin(M48T59_READ(M48T59_ALARM_SEC
));
192 /* Clear the READ bit */
193 M48T59_CLEAR_BITS(M48T59_CNTL_READ
, M48T59_CNTL
);
194 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
196 dev_dbg(dev
, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
197 tm
->tm_year
+ 1900, tm
->tm_mon
, tm
->tm_mday
,
198 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
199 return rtc_valid_tm(tm
);
203 * Set alarm time and date in RTC
205 static int m48t59_rtc_setalarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
207 struct platform_device
*pdev
= to_platform_device(dev
);
208 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
209 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
210 struct rtc_time
*tm
= &alrm
->time
;
211 u8 mday
, hour
, min
, sec
;
213 int year
= tm
->tm_year
;
216 /* Sun SPARC machines count years since 1968 */
220 /* If no irq, we don't support ALARM */
221 if (m48t59
->irq
== NO_IRQ
)
228 * 0xff means "always match"
231 mday
= (mday
>= 1 && mday
<= 31) ? bin2bcd(mday
) : 0xff;
233 mday
= M48T59_READ(M48T59_MDAY
);
236 hour
= (hour
< 24) ? bin2bcd(hour
) : 0x00;
239 min
= (min
< 60) ? bin2bcd(min
) : 0x00;
242 sec
= (sec
< 60) ? bin2bcd(sec
) : 0x00;
244 spin_lock_irqsave(&m48t59
->lock
, flags
);
245 /* Issue the WRITE command */
246 M48T59_SET_BITS(M48T59_CNTL_WRITE
, M48T59_CNTL
);
248 M48T59_WRITE(mday
, M48T59_ALARM_DATE
);
249 M48T59_WRITE(hour
, M48T59_ALARM_HOUR
);
250 M48T59_WRITE(min
, M48T59_ALARM_MIN
);
251 M48T59_WRITE(sec
, M48T59_ALARM_SEC
);
253 /* Clear the WRITE bit */
254 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE
, M48T59_CNTL
);
255 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
257 dev_dbg(dev
, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
258 year
+ 1900, tm
->tm_mon
, tm
->tm_mday
,
259 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
264 * Handle commands from user-space
266 static int m48t59_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
268 struct platform_device
*pdev
= to_platform_device(dev
);
269 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
270 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
273 spin_lock_irqsave(&m48t59
->lock
, flags
);
275 M48T59_WRITE(M48T59_INTR_AFE
, M48T59_INTR
);
277 M48T59_WRITE(0x00, M48T59_INTR
);
278 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
283 static int m48t59_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
285 struct platform_device
*pdev
= to_platform_device(dev
);
286 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
287 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
291 spin_lock_irqsave(&m48t59
->lock
, flags
);
292 val
= M48T59_READ(M48T59_FLAGS
);
293 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
295 seq_printf(seq
, "battery\t\t: %s\n",
296 (val
& M48T59_FLAGS_BF
) ? "low" : "normal");
301 * IRQ handler for the RTC
303 static irqreturn_t
m48t59_rtc_interrupt(int irq
, void *dev_id
)
305 struct device
*dev
= (struct device
*)dev_id
;
306 struct platform_device
*pdev
= to_platform_device(dev
);
307 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
308 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
311 spin_lock(&m48t59
->lock
);
312 event
= M48T59_READ(M48T59_FLAGS
);
313 spin_unlock(&m48t59
->lock
);
315 if (event
& M48T59_FLAGS_AF
) {
316 rtc_update_irq(m48t59
->rtc
, 1, (RTC_AF
| RTC_IRQF
));
323 static const struct rtc_class_ops m48t59_rtc_ops
= {
324 .read_time
= m48t59_rtc_read_time
,
325 .set_time
= m48t59_rtc_set_time
,
326 .read_alarm
= m48t59_rtc_readalarm
,
327 .set_alarm
= m48t59_rtc_setalarm
,
328 .proc
= m48t59_rtc_proc
,
329 .alarm_irq_enable
= m48t59_rtc_alarm_irq_enable
,
332 static const struct rtc_class_ops m48t02_rtc_ops
= {
333 .read_time
= m48t59_rtc_read_time
,
334 .set_time
= m48t59_rtc_set_time
,
337 static ssize_t
m48t59_nvram_read(struct file
*filp
, struct kobject
*kobj
,
338 struct bin_attribute
*bin_attr
,
339 char *buf
, loff_t pos
, size_t size
)
341 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
342 struct platform_device
*pdev
= to_platform_device(dev
);
343 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
344 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
348 for (; size
> 0 && pos
< pdata
->offset
; cnt
++, size
--) {
349 spin_lock_irqsave(&m48t59
->lock
, flags
);
350 *buf
++ = M48T59_READ(cnt
);
351 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
357 static ssize_t
m48t59_nvram_write(struct file
*filp
, struct kobject
*kobj
,
358 struct bin_attribute
*bin_attr
,
359 char *buf
, loff_t pos
, size_t size
)
361 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
362 struct platform_device
*pdev
= to_platform_device(dev
);
363 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
364 struct m48t59_private
*m48t59
= platform_get_drvdata(pdev
);
368 for (; size
> 0 && pos
< pdata
->offset
; cnt
++, size
--) {
369 spin_lock_irqsave(&m48t59
->lock
, flags
);
370 M48T59_WRITE(*buf
++, cnt
);
371 spin_unlock_irqrestore(&m48t59
->lock
, flags
);
377 static struct bin_attribute m48t59_nvram_attr
= {
380 .mode
= S_IRUGO
| S_IWUSR
,
382 .read
= m48t59_nvram_read
,
383 .write
= m48t59_nvram_write
,
386 static int m48t59_rtc_probe(struct platform_device
*pdev
)
388 struct m48t59_plat_data
*pdata
= dev_get_platdata(&pdev
->dev
);
389 struct m48t59_private
*m48t59
= NULL
;
390 struct resource
*res
;
393 const struct rtc_class_ops
*ops
;
395 /* This chip could be memory-mapped or I/O-mapped */
396 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
398 res
= platform_get_resource(pdev
, IORESOURCE_IO
, 0);
403 if (res
->flags
& IORESOURCE_IO
) {
404 /* If we are I/O-mapped, the platform should provide
405 * the operations accessing chip registers.
407 if (!pdata
|| !pdata
->write_byte
|| !pdata
->read_byte
)
409 } else if (res
->flags
& IORESOURCE_MEM
) {
410 /* we are memory-mapped */
412 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
),
416 /* Ensure we only kmalloc platform data once */
417 pdev
->dev
.platform_data
= pdata
;
420 pdata
->type
= M48T59RTC_TYPE_M48T59
;
422 /* Try to use the generic memory read/write ops */
423 if (!pdata
->write_byte
)
424 pdata
->write_byte
= m48t59_mem_writeb
;
425 if (!pdata
->read_byte
)
426 pdata
->read_byte
= m48t59_mem_readb
;
429 m48t59
= devm_kzalloc(&pdev
->dev
, sizeof(*m48t59
), GFP_KERNEL
);
433 m48t59
->ioaddr
= pdata
->ioaddr
;
435 if (!m48t59
->ioaddr
) {
436 /* ioaddr not mapped externally */
437 m48t59
->ioaddr
= devm_ioremap(&pdev
->dev
, res
->start
,
443 /* Try to get irq number. We also can work in
444 * the mode without IRQ.
446 m48t59
->irq
= platform_get_irq(pdev
, 0);
447 if (m48t59
->irq
<= 0)
448 m48t59
->irq
= NO_IRQ
;
450 if (m48t59
->irq
!= NO_IRQ
) {
451 ret
= devm_request_irq(&pdev
->dev
, m48t59
->irq
,
452 m48t59_rtc_interrupt
, IRQF_SHARED
,
453 "rtc-m48t59", &pdev
->dev
);
457 switch (pdata
->type
) {
458 case M48T59RTC_TYPE_M48T59
:
460 ops
= &m48t59_rtc_ops
;
461 pdata
->offset
= 0x1ff0;
463 case M48T59RTC_TYPE_M48T02
:
465 ops
= &m48t02_rtc_ops
;
466 pdata
->offset
= 0x7f0;
468 case M48T59RTC_TYPE_M48T08
:
470 ops
= &m48t02_rtc_ops
;
471 pdata
->offset
= 0x1ff0;
474 dev_err(&pdev
->dev
, "Unknown RTC type\n");
478 spin_lock_init(&m48t59
->lock
);
479 platform_set_drvdata(pdev
, m48t59
);
481 m48t59
->rtc
= devm_rtc_device_register(&pdev
->dev
, name
, ops
,
483 if (IS_ERR(m48t59
->rtc
))
484 return PTR_ERR(m48t59
->rtc
);
486 m48t59_nvram_attr
.size
= pdata
->offset
;
488 ret
= sysfs_create_bin_file(&pdev
->dev
.kobj
, &m48t59_nvram_attr
);
495 static int m48t59_rtc_remove(struct platform_device
*pdev
)
497 sysfs_remove_bin_file(&pdev
->dev
.kobj
, &m48t59_nvram_attr
);
501 /* work with hotplug and coldplug */
502 MODULE_ALIAS("platform:rtc-m48t59");
504 static struct platform_driver m48t59_rtc_driver
= {
506 .name
= "rtc-m48t59",
508 .probe
= m48t59_rtc_probe
,
509 .remove
= m48t59_rtc_remove
,
512 module_platform_driver(m48t59_rtc_driver
);
514 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
515 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
516 MODULE_LICENSE("GPL");