2 * drivers/rtc/rtc-pl031.c
4 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
6 * Author: Deepak Saxena <dsaxena@plexity.net>
8 * Copyright 2006 (c) MontaVista Software, Inc.
10 * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
11 * Copyright 2010 (c) ST-Ericsson AB
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
18 #include <linux/module.h>
19 #include <linux/rtc.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/amba/bus.h>
24 #include <linux/bcd.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
29 * Register definitions
31 #define RTC_DR 0x00 /* Data read register */
32 #define RTC_MR 0x04 /* Match register */
33 #define RTC_LR 0x08 /* Data load register */
34 #define RTC_CR 0x0c /* Control register */
35 #define RTC_IMSC 0x10 /* Interrupt mask and set register */
36 #define RTC_RIS 0x14 /* Raw interrupt status register */
37 #define RTC_MIS 0x18 /* Masked interrupt status register */
38 #define RTC_ICR 0x1c /* Interrupt clear register */
39 /* ST variants have additional timer functionality */
40 #define RTC_TDR 0x20 /* Timer data read register */
41 #define RTC_TLR 0x24 /* Timer data load register */
42 #define RTC_TCR 0x28 /* Timer control register */
43 #define RTC_YDR 0x30 /* Year data read register */
44 #define RTC_YMR 0x34 /* Year match register */
45 #define RTC_YLR 0x38 /* Year data load register */
47 #define RTC_CR_EN (1 << 0) /* counter enable bit */
48 #define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */
50 #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */
52 /* Common bit definitions for Interrupt status and control registers */
53 #define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */
54 #define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */
56 /* Common bit definations for ST v2 for reading/writing time */
57 #define RTC_SEC_SHIFT 0
58 #define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */
59 #define RTC_MIN_SHIFT 6
60 #define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */
61 #define RTC_HOUR_SHIFT 12
62 #define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */
63 #define RTC_WDAY_SHIFT 17
64 #define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */
65 #define RTC_MDAY_SHIFT 20
66 #define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */
67 #define RTC_MON_SHIFT 25
68 #define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */
70 #define RTC_TIMER_FREQ 32768
73 * struct pl031_vendor_data - per-vendor variations
74 * @ops: the vendor-specific operations used on this silicon version
75 * @clockwatch: if this is an ST Microelectronics silicon version with a
77 * @st_weekday: if this is an ST Microelectronics silicon version that need
79 * @irqflags: special IRQ flags per variant
81 struct pl031_vendor_data
{
82 struct rtc_class_ops ops
;
85 unsigned long irqflags
;
89 struct pl031_vendor_data
*vendor
;
90 struct rtc_device
*rtc
;
94 static int pl031_alarm_irq_enable(struct device
*dev
,
97 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
100 /* Clear any pending alarm interrupts. */
101 writel(RTC_BIT_AI
, ldata
->base
+ RTC_ICR
);
103 imsc
= readl(ldata
->base
+ RTC_IMSC
);
106 writel(imsc
| RTC_BIT_AI
, ldata
->base
+ RTC_IMSC
);
108 writel(imsc
& ~RTC_BIT_AI
, ldata
->base
+ RTC_IMSC
);
114 * Convert Gregorian date to ST v2 RTC format.
116 static int pl031_stv2_tm_to_time(struct device
*dev
,
117 struct rtc_time
*tm
, unsigned long *st_time
,
118 unsigned long *bcd_year
)
120 int year
= tm
->tm_year
+ 1900;
121 int wday
= tm
->tm_wday
;
123 /* wday masking is not working in hardware so wday must be valid */
124 if (wday
< -1 || wday
> 6) {
125 dev_err(dev
, "invalid wday value %d\n", tm
->tm_wday
);
127 } else if (wday
== -1) {
128 /* wday is not provided, calculate it here */
130 struct rtc_time calc_tm
;
132 rtc_tm_to_time(tm
, &time
);
133 rtc_time_to_tm(time
, &calc_tm
);
134 wday
= calc_tm
.tm_wday
;
137 *bcd_year
= (bin2bcd(year
% 100) | bin2bcd(year
/ 100) << 8);
139 *st_time
= ((tm
->tm_mon
+ 1) << RTC_MON_SHIFT
)
140 | (tm
->tm_mday
<< RTC_MDAY_SHIFT
)
141 | ((wday
+ 1) << RTC_WDAY_SHIFT
)
142 | (tm
->tm_hour
<< RTC_HOUR_SHIFT
)
143 | (tm
->tm_min
<< RTC_MIN_SHIFT
)
144 | (tm
->tm_sec
<< RTC_SEC_SHIFT
);
150 * Convert ST v2 RTC format to Gregorian date.
152 static int pl031_stv2_time_to_tm(unsigned long st_time
, unsigned long bcd_year
,
155 tm
->tm_year
= bcd2bin(bcd_year
) + (bcd2bin(bcd_year
>> 8) * 100);
156 tm
->tm_mon
= ((st_time
& RTC_MON_MASK
) >> RTC_MON_SHIFT
) - 1;
157 tm
->tm_mday
= ((st_time
& RTC_MDAY_MASK
) >> RTC_MDAY_SHIFT
);
158 tm
->tm_wday
= ((st_time
& RTC_WDAY_MASK
) >> RTC_WDAY_SHIFT
) - 1;
159 tm
->tm_hour
= ((st_time
& RTC_HOUR_MASK
) >> RTC_HOUR_SHIFT
);
160 tm
->tm_min
= ((st_time
& RTC_MIN_MASK
) >> RTC_MIN_SHIFT
);
161 tm
->tm_sec
= ((st_time
& RTC_SEC_MASK
) >> RTC_SEC_SHIFT
);
163 tm
->tm_yday
= rtc_year_days(tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
);
169 static int pl031_stv2_read_time(struct device
*dev
, struct rtc_time
*tm
)
171 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
173 pl031_stv2_time_to_tm(readl(ldata
->base
+ RTC_DR
),
174 readl(ldata
->base
+ RTC_YDR
), tm
);
179 static int pl031_stv2_set_time(struct device
*dev
, struct rtc_time
*tm
)
182 unsigned long bcd_year
;
183 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
186 ret
= pl031_stv2_tm_to_time(dev
, tm
, &time
, &bcd_year
);
188 writel(bcd_year
, ldata
->base
+ RTC_YLR
);
189 writel(time
, ldata
->base
+ RTC_LR
);
195 static int pl031_stv2_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
197 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
200 ret
= pl031_stv2_time_to_tm(readl(ldata
->base
+ RTC_MR
),
201 readl(ldata
->base
+ RTC_YMR
), &alarm
->time
);
203 alarm
->pending
= readl(ldata
->base
+ RTC_RIS
) & RTC_BIT_AI
;
204 alarm
->enabled
= readl(ldata
->base
+ RTC_IMSC
) & RTC_BIT_AI
;
209 static int pl031_stv2_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
211 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
213 unsigned long bcd_year
;
216 /* At the moment, we can only deal with non-wildcarded alarm times. */
217 ret
= rtc_valid_tm(&alarm
->time
);
219 ret
= pl031_stv2_tm_to_time(dev
, &alarm
->time
,
222 writel(bcd_year
, ldata
->base
+ RTC_YMR
);
223 writel(time
, ldata
->base
+ RTC_MR
);
225 pl031_alarm_irq_enable(dev
, alarm
->enabled
);
232 static irqreturn_t
pl031_interrupt(int irq
, void *dev_id
)
234 struct pl031_local
*ldata
= dev_id
;
235 unsigned long rtcmis
;
236 unsigned long events
= 0;
238 rtcmis
= readl(ldata
->base
+ RTC_MIS
);
239 if (rtcmis
& RTC_BIT_AI
) {
240 writel(RTC_BIT_AI
, ldata
->base
+ RTC_ICR
);
241 events
|= (RTC_AF
| RTC_IRQF
);
242 rtc_update_irq(ldata
->rtc
, 1, events
);
250 static int pl031_read_time(struct device
*dev
, struct rtc_time
*tm
)
252 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
254 rtc_time_to_tm(readl(ldata
->base
+ RTC_DR
), tm
);
259 static int pl031_set_time(struct device
*dev
, struct rtc_time
*tm
)
262 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
265 ret
= rtc_tm_to_time(tm
, &time
);
268 writel(time
, ldata
->base
+ RTC_LR
);
273 static int pl031_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
275 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
277 rtc_time_to_tm(readl(ldata
->base
+ RTC_MR
), &alarm
->time
);
279 alarm
->pending
= readl(ldata
->base
+ RTC_RIS
) & RTC_BIT_AI
;
280 alarm
->enabled
= readl(ldata
->base
+ RTC_IMSC
) & RTC_BIT_AI
;
285 static int pl031_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
287 struct pl031_local
*ldata
= dev_get_drvdata(dev
);
291 /* At the moment, we can only deal with non-wildcarded alarm times. */
292 ret
= rtc_valid_tm(&alarm
->time
);
294 ret
= rtc_tm_to_time(&alarm
->time
, &time
);
296 writel(time
, ldata
->base
+ RTC_MR
);
297 pl031_alarm_irq_enable(dev
, alarm
->enabled
);
304 static int pl031_remove(struct amba_device
*adev
)
306 struct pl031_local
*ldata
= dev_get_drvdata(&adev
->dev
);
308 amba_set_drvdata(adev
, NULL
);
309 free_irq(adev
->irq
[0], ldata
->rtc
);
310 rtc_device_unregister(ldata
->rtc
);
311 iounmap(ldata
->base
);
313 amba_release_regions(adev
);
318 static int pl031_probe(struct amba_device
*adev
, const struct amba_id
*id
)
321 struct pl031_local
*ldata
;
322 struct pl031_vendor_data
*vendor
= id
->data
;
323 struct rtc_class_ops
*ops
= &vendor
->ops
;
324 unsigned long time
, data
;
326 ret
= amba_request_regions(adev
, NULL
);
330 ldata
= kzalloc(sizeof(struct pl031_local
), GFP_KERNEL
);
335 ldata
->vendor
= vendor
;
337 ldata
->base
= ioremap(adev
->res
.start
, resource_size(&adev
->res
));
344 amba_set_drvdata(adev
, ldata
);
346 dev_dbg(&adev
->dev
, "designer ID = 0x%02x\n", amba_manf(adev
));
347 dev_dbg(&adev
->dev
, "revision = 0x%01x\n", amba_rev(adev
));
349 data
= readl(ldata
->base
+ RTC_CR
);
350 /* Enable the clockwatch on ST Variants */
351 if (vendor
->clockwatch
)
353 writel(data
| RTC_CR_EN
, ldata
->base
+ RTC_CR
);
356 * On ST PL031 variants, the RTC reset value does not provide correct
357 * weekday for 2000-01-01. Correct the erroneous sunday to saturday.
359 if (vendor
->st_weekday
) {
360 if (readl(ldata
->base
+ RTC_YDR
) == 0x2000) {
361 time
= readl(ldata
->base
+ RTC_DR
);
363 (RTC_MON_MASK
| RTC_MDAY_MASK
| RTC_WDAY_MASK
))
365 time
= time
| (0x7 << RTC_WDAY_SHIFT
);
366 writel(0x2000, ldata
->base
+ RTC_YLR
);
367 writel(time
, ldata
->base
+ RTC_LR
);
372 ldata
->rtc
= rtc_device_register("pl031", &adev
->dev
, ops
,
374 if (IS_ERR(ldata
->rtc
)) {
375 ret
= PTR_ERR(ldata
->rtc
);
379 if (request_irq(adev
->irq
[0], pl031_interrupt
,
380 vendor
->irqflags
, "rtc-pl031", ldata
)) {
388 rtc_device_unregister(ldata
->rtc
);
390 iounmap(ldata
->base
);
391 amba_set_drvdata(adev
, NULL
);
395 amba_release_regions(adev
);
401 /* Operations for the original ARM version */
402 static struct pl031_vendor_data arm_pl031
= {
404 .read_time
= pl031_read_time
,
405 .set_time
= pl031_set_time
,
406 .read_alarm
= pl031_read_alarm
,
407 .set_alarm
= pl031_set_alarm
,
408 .alarm_irq_enable
= pl031_alarm_irq_enable
,
410 .irqflags
= IRQF_NO_SUSPEND
,
413 /* The First ST derivative */
414 static struct pl031_vendor_data stv1_pl031
= {
416 .read_time
= pl031_read_time
,
417 .set_time
= pl031_set_time
,
418 .read_alarm
= pl031_read_alarm
,
419 .set_alarm
= pl031_set_alarm
,
420 .alarm_irq_enable
= pl031_alarm_irq_enable
,
424 .irqflags
= IRQF_NO_SUSPEND
,
427 /* And the second ST derivative */
428 static struct pl031_vendor_data stv2_pl031
= {
430 .read_time
= pl031_stv2_read_time
,
431 .set_time
= pl031_stv2_set_time
,
432 .read_alarm
= pl031_stv2_read_alarm
,
433 .set_alarm
= pl031_stv2_set_alarm
,
434 .alarm_irq_enable
= pl031_alarm_irq_enable
,
439 * This variant shares the IRQ with another block and must not
440 * suspend that IRQ line.
442 .irqflags
= IRQF_SHARED
| IRQF_NO_SUSPEND
,
445 static struct amba_id pl031_ids
[] = {
451 /* ST Micro variants */
465 MODULE_DEVICE_TABLE(amba
, pl031_ids
);
467 static struct amba_driver pl031_driver
= {
471 .id_table
= pl031_ids
,
472 .probe
= pl031_probe
,
473 .remove
= pl031_remove
,
476 module_amba_driver(pl031_driver
);
478 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
479 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
480 MODULE_LICENSE("GPL");