2 * A RTC driver for the Simtek STK17TA8
4 * By Thomas Hommel <thomas.hommel@gefanuc.com>
6 * Based on the DS1553 driver from
7 * Atsushi Nemoto <anemo@mba.ocn.ne.jp>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/bcd.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/delay.h>
18 #include <linux/jiffies.h>
19 #include <linux/interrupt.h>
20 #include <linux/rtc.h>
21 #include <linux/platform_device.h>
24 #define DRV_VERSION "0.1"
26 #define RTC_REG_SIZE 0x20000
27 #define RTC_OFFSET 0x1fff0
29 #define RTC_FLAGS (RTC_OFFSET + 0)
30 #define RTC_CENTURY (RTC_OFFSET + 1)
31 #define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
32 #define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
33 #define RTC_HOURS_ALARM (RTC_OFFSET + 4)
34 #define RTC_DATE_ALARM (RTC_OFFSET + 5)
35 #define RTC_INTERRUPTS (RTC_OFFSET + 6)
36 #define RTC_WATCHDOG (RTC_OFFSET + 7)
37 #define RTC_CALIBRATION (RTC_OFFSET + 8)
38 #define RTC_SECONDS (RTC_OFFSET + 9)
39 #define RTC_MINUTES (RTC_OFFSET + 10)
40 #define RTC_HOURS (RTC_OFFSET + 11)
41 #define RTC_DAY (RTC_OFFSET + 12)
42 #define RTC_DATE (RTC_OFFSET + 13)
43 #define RTC_MONTH (RTC_OFFSET + 14)
44 #define RTC_YEAR (RTC_OFFSET + 15)
46 #define RTC_SECONDS_MASK 0x7f
47 #define RTC_DAY_MASK 0x07
48 #define RTC_CAL_MASK 0x3f
50 /* Bits in the Calibration register */
53 /* Bits in the Flags register */
54 #define RTC_FLAGS_AF 0x40
55 #define RTC_FLAGS_PF 0x20
56 #define RTC_WRITE 0x02
59 /* Bits in the Interrupts register */
60 #define RTC_INTS_AIE 0x40
62 struct rtc_plat_data
{
63 struct rtc_device
*rtc
;
65 unsigned long baseaddr
;
66 unsigned long last_jiffies
;
75 static int stk17ta8_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
77 struct platform_device
*pdev
= to_platform_device(dev
);
78 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
79 void __iomem
*ioaddr
= pdata
->ioaddr
;
82 flags
= readb(pdata
->ioaddr
+ RTC_FLAGS
);
83 writeb(flags
| RTC_WRITE
, pdata
->ioaddr
+ RTC_FLAGS
);
85 writeb(BIN2BCD(tm
->tm_year
% 100), ioaddr
+ RTC_YEAR
);
86 writeb(BIN2BCD(tm
->tm_mon
+ 1), ioaddr
+ RTC_MONTH
);
87 writeb(BIN2BCD(tm
->tm_wday
) & RTC_DAY_MASK
, ioaddr
+ RTC_DAY
);
88 writeb(BIN2BCD(tm
->tm_mday
), ioaddr
+ RTC_DATE
);
89 writeb(BIN2BCD(tm
->tm_hour
), ioaddr
+ RTC_HOURS
);
90 writeb(BIN2BCD(tm
->tm_min
), ioaddr
+ RTC_MINUTES
);
91 writeb(BIN2BCD(tm
->tm_sec
) & RTC_SECONDS_MASK
, ioaddr
+ RTC_SECONDS
);
92 writeb(BIN2BCD((tm
->tm_year
+ 1900) / 100), ioaddr
+ RTC_CENTURY
);
94 writeb(flags
& ~RTC_WRITE
, pdata
->ioaddr
+ RTC_FLAGS
);
98 static int stk17ta8_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
100 struct platform_device
*pdev
= to_platform_device(dev
);
101 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
102 void __iomem
*ioaddr
= pdata
->ioaddr
;
103 unsigned int year
, month
, day
, hour
, minute
, second
, week
;
104 unsigned int century
;
107 /* give enough time to update RTC in case of continuous read */
108 if (pdata
->last_jiffies
== jiffies
)
110 pdata
->last_jiffies
= jiffies
;
112 flags
= readb(pdata
->ioaddr
+ RTC_FLAGS
);
113 writeb(flags
| RTC_READ
, ioaddr
+ RTC_FLAGS
);
114 second
= readb(ioaddr
+ RTC_SECONDS
) & RTC_SECONDS_MASK
;
115 minute
= readb(ioaddr
+ RTC_MINUTES
);
116 hour
= readb(ioaddr
+ RTC_HOURS
);
117 day
= readb(ioaddr
+ RTC_DATE
);
118 week
= readb(ioaddr
+ RTC_DAY
) & RTC_DAY_MASK
;
119 month
= readb(ioaddr
+ RTC_MONTH
);
120 year
= readb(ioaddr
+ RTC_YEAR
);
121 century
= readb(ioaddr
+ RTC_CENTURY
);
122 writeb(flags
& ~RTC_READ
, ioaddr
+ RTC_FLAGS
);
123 tm
->tm_sec
= BCD2BIN(second
);
124 tm
->tm_min
= BCD2BIN(minute
);
125 tm
->tm_hour
= BCD2BIN(hour
);
126 tm
->tm_mday
= BCD2BIN(day
);
127 tm
->tm_wday
= BCD2BIN(week
);
128 tm
->tm_mon
= BCD2BIN(month
) - 1;
129 /* year is 1900 + tm->tm_year */
130 tm
->tm_year
= BCD2BIN(year
) + BCD2BIN(century
) * 100 - 1900;
132 if (rtc_valid_tm(tm
) < 0) {
133 dev_err(dev
, "retrieved date/time is not valid.\n");
134 rtc_time_to_tm(0, tm
);
139 static void stk17ta8_rtc_update_alarm(struct rtc_plat_data
*pdata
)
141 void __iomem
*ioaddr
= pdata
->ioaddr
;
142 unsigned long irqflags
;
145 spin_lock_irqsave(&pdata
->rtc
->irq_lock
, irqflags
);
147 flags
= readb(ioaddr
+ RTC_FLAGS
);
148 writeb(flags
| RTC_WRITE
, ioaddr
+ RTC_FLAGS
);
150 writeb(pdata
->alrm_mday
< 0 || (pdata
->irqen
& RTC_UF
) ?
151 0x80 : BIN2BCD(pdata
->alrm_mday
),
152 ioaddr
+ RTC_DATE_ALARM
);
153 writeb(pdata
->alrm_hour
< 0 || (pdata
->irqen
& RTC_UF
) ?
154 0x80 : BIN2BCD(pdata
->alrm_hour
),
155 ioaddr
+ RTC_HOURS_ALARM
);
156 writeb(pdata
->alrm_min
< 0 || (pdata
->irqen
& RTC_UF
) ?
157 0x80 : BIN2BCD(pdata
->alrm_min
),
158 ioaddr
+ RTC_MINUTES_ALARM
);
159 writeb(pdata
->alrm_sec
< 0 || (pdata
->irqen
& RTC_UF
) ?
160 0x80 : BIN2BCD(pdata
->alrm_sec
),
161 ioaddr
+ RTC_SECONDS_ALARM
);
162 writeb(pdata
->irqen
? RTC_INTS_AIE
: 0, ioaddr
+ RTC_INTERRUPTS
);
163 readb(ioaddr
+ RTC_FLAGS
); /* clear interrupts */
164 writeb(flags
& ~RTC_WRITE
, ioaddr
+ RTC_FLAGS
);
165 spin_unlock_irqrestore(&pdata
->rtc
->irq_lock
, irqflags
);
168 static int stk17ta8_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
170 struct platform_device
*pdev
= to_platform_device(dev
);
171 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
175 pdata
->alrm_mday
= alrm
->time
.tm_mday
;
176 pdata
->alrm_hour
= alrm
->time
.tm_hour
;
177 pdata
->alrm_min
= alrm
->time
.tm_min
;
178 pdata
->alrm_sec
= alrm
->time
.tm_sec
;
180 pdata
->irqen
|= RTC_AF
;
181 stk17ta8_rtc_update_alarm(pdata
);
185 static int stk17ta8_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
187 struct platform_device
*pdev
= to_platform_device(dev
);
188 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
192 alrm
->time
.tm_mday
= pdata
->alrm_mday
< 0 ? 0 : pdata
->alrm_mday
;
193 alrm
->time
.tm_hour
= pdata
->alrm_hour
< 0 ? 0 : pdata
->alrm_hour
;
194 alrm
->time
.tm_min
= pdata
->alrm_min
< 0 ? 0 : pdata
->alrm_min
;
195 alrm
->time
.tm_sec
= pdata
->alrm_sec
< 0 ? 0 : pdata
->alrm_sec
;
196 alrm
->enabled
= (pdata
->irqen
& RTC_AF
) ? 1 : 0;
200 static irqreturn_t
stk17ta8_rtc_interrupt(int irq
, void *dev_id
)
202 struct platform_device
*pdev
= dev_id
;
203 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
204 void __iomem
*ioaddr
= pdata
->ioaddr
;
205 unsigned long events
= RTC_IRQF
;
207 /* read and clear interrupt */
208 if (!(readb(ioaddr
+ RTC_FLAGS
) & RTC_FLAGS_AF
))
210 if (readb(ioaddr
+ RTC_SECONDS_ALARM
) & 0x80)
214 rtc_update_irq(pdata
->rtc
, 1, events
);
218 static void stk17ta8_rtc_release(struct device
*dev
)
220 struct platform_device
*pdev
= to_platform_device(dev
);
221 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
223 if (pdata
->irq
>= 0) {
225 stk17ta8_rtc_update_alarm(pdata
);
229 static int stk17ta8_rtc_ioctl(struct device
*dev
, unsigned int cmd
,
232 struct platform_device
*pdev
= to_platform_device(dev
);
233 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
236 return -ENOIOCTLCMD
; /* fall back into rtc-dev's emulation */
239 pdata
->irqen
&= ~RTC_AF
;
240 stk17ta8_rtc_update_alarm(pdata
);
243 pdata
->irqen
|= RTC_AF
;
244 stk17ta8_rtc_update_alarm(pdata
);
252 static const struct rtc_class_ops stk17ta8_rtc_ops
= {
253 .read_time
= stk17ta8_rtc_read_time
,
254 .set_time
= stk17ta8_rtc_set_time
,
255 .read_alarm
= stk17ta8_rtc_read_alarm
,
256 .set_alarm
= stk17ta8_rtc_set_alarm
,
257 .release
= stk17ta8_rtc_release
,
258 .ioctl
= stk17ta8_rtc_ioctl
,
261 static ssize_t
stk17ta8_nvram_read(struct kobject
*kobj
,
262 struct bin_attribute
*attr
, char *buf
,
263 loff_t pos
, size_t size
)
265 struct platform_device
*pdev
=
266 to_platform_device(container_of(kobj
, struct device
, kobj
));
267 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
268 void __iomem
*ioaddr
= pdata
->ioaddr
;
271 for (count
= 0; size
> 0 && pos
< RTC_OFFSET
; count
++, size
--)
272 *buf
++ = readb(ioaddr
+ pos
++);
276 static ssize_t
stk17ta8_nvram_write(struct kobject
*kobj
,
277 struct bin_attribute
*attr
, char *buf
,
278 loff_t pos
, size_t size
)
280 struct platform_device
*pdev
=
281 to_platform_device(container_of(kobj
, struct device
, kobj
));
282 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
283 void __iomem
*ioaddr
= pdata
->ioaddr
;
286 for (count
= 0; size
> 0 && pos
< RTC_OFFSET
; count
++, size
--)
287 writeb(*buf
++, ioaddr
+ pos
++);
291 static struct bin_attribute stk17ta8_nvram_attr
= {
294 .mode
= S_IRUGO
| S_IWUGO
,
295 .owner
= THIS_MODULE
,
298 .read
= stk17ta8_nvram_read
,
299 .write
= stk17ta8_nvram_write
,
302 static int __init
stk17ta8_rtc_probe(struct platform_device
*pdev
)
304 struct rtc_device
*rtc
;
305 struct resource
*res
;
308 struct rtc_plat_data
*pdata
;
309 void __iomem
*ioaddr
= NULL
;
312 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
316 pdata
= kzalloc(sizeof(*pdata
), GFP_KERNEL
);
320 if (!request_mem_region(res
->start
, RTC_REG_SIZE
, pdev
->name
)) {
324 pdata
->baseaddr
= res
->start
;
325 ioaddr
= ioremap(pdata
->baseaddr
, RTC_REG_SIZE
);
330 pdata
->ioaddr
= ioaddr
;
331 pdata
->irq
= platform_get_irq(pdev
, 0);
333 /* turn RTC on if it was not on */
334 cal
= readb(ioaddr
+ RTC_CALIBRATION
);
335 if (cal
& RTC_STOP
) {
337 flags
= readb(ioaddr
+ RTC_FLAGS
);
338 writeb(flags
| RTC_WRITE
, ioaddr
+ RTC_FLAGS
);
339 writeb(cal
, ioaddr
+ RTC_CALIBRATION
);
340 writeb(flags
& ~RTC_WRITE
, ioaddr
+ RTC_FLAGS
);
342 if (readb(ioaddr
+ RTC_FLAGS
) & RTC_FLAGS_PF
)
343 dev_warn(&pdev
->dev
, "voltage-low detected.\n");
345 if (pdata
->irq
>= 0) {
346 writeb(0, ioaddr
+ RTC_INTERRUPTS
);
347 if (request_irq(pdata
->irq
, stk17ta8_rtc_interrupt
,
348 IRQF_DISABLED
| IRQF_SHARED
,
349 pdev
->name
, pdev
) < 0) {
350 dev_warn(&pdev
->dev
, "interrupt not available.\n");
355 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
,
356 &stk17ta8_rtc_ops
, THIS_MODULE
);
362 pdata
->last_jiffies
= jiffies
;
363 platform_set_drvdata(pdev
, pdata
);
364 ret
= sysfs_create_bin_file(&pdev
->dev
.kobj
, &stk17ta8_nvram_attr
);
370 rtc_device_unregister(pdata
->rtc
);
372 free_irq(pdata
->irq
, pdev
);
376 release_mem_region(pdata
->baseaddr
, RTC_REG_SIZE
);
381 static int __devexit
stk17ta8_rtc_remove(struct platform_device
*pdev
)
383 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
385 sysfs_remove_bin_file(&pdev
->dev
.kobj
, &stk17ta8_nvram_attr
);
386 rtc_device_unregister(pdata
->rtc
);
387 if (pdata
->irq
>= 0) {
388 writeb(0, pdata
->ioaddr
+ RTC_INTERRUPTS
);
389 free_irq(pdata
->irq
, pdev
);
391 iounmap(pdata
->ioaddr
);
392 release_mem_region(pdata
->baseaddr
, RTC_REG_SIZE
);
397 static struct platform_driver stk17ta8_rtc_driver
= {
398 .probe
= stk17ta8_rtc_probe
,
399 .remove
= __devexit_p(stk17ta8_rtc_remove
),
402 .owner
= THIS_MODULE
,
406 static __init
int stk17ta8_init(void)
408 return platform_driver_register(&stk17ta8_rtc_driver
);
411 static __exit
void stk17ta8_exit(void)
413 return platform_driver_unregister(&stk17ta8_rtc_driver
);
416 module_init(stk17ta8_init
);
417 module_exit(stk17ta8_exit
);
419 MODULE_AUTHOR("Thomas Hommel <thomas.hommel@gefanuc.com>");
420 MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
421 MODULE_LICENSE("GPL");
422 MODULE_VERSION(DRV_VERSION
);