2 * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
4 * The code contained herein is licensed under the GNU General Public
5 * License. You may obtain a copy of the GNU General Public License
6 * Version 2 or later at the following locations:
8 * http://www.opensource.org/licenses/gpl-license.html
9 * http://www.gnu.org/copyleft/gpl.html
13 #include <linux/rtc.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/interrupt.h>
17 #include <linux/platform_device.h>
18 #include <linux/clk.h>
20 #include <mach/hardware.h>
22 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
23 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
24 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
26 #define RTC_SW_BIT (1 << 0)
27 #define RTC_ALM_BIT (1 << 2)
28 #define RTC_1HZ_BIT (1 << 4)
29 #define RTC_2HZ_BIT (1 << 7)
30 #define RTC_SAM0_BIT (1 << 8)
31 #define RTC_SAM1_BIT (1 << 9)
32 #define RTC_SAM2_BIT (1 << 10)
33 #define RTC_SAM3_BIT (1 << 11)
34 #define RTC_SAM4_BIT (1 << 12)
35 #define RTC_SAM5_BIT (1 << 13)
36 #define RTC_SAM6_BIT (1 << 14)
37 #define RTC_SAM7_BIT (1 << 15)
38 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
39 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
40 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
42 #define RTC_ENABLE_BIT (1 << 7)
45 #define MAX_PIE_FREQ 512
46 static const u32 PIE_BIT_DEF
[MAX_PIE_NUM
][2] = {
53 { 128, RTC_SAM5_BIT
},
54 { 256, RTC_SAM6_BIT
},
55 { MAX_PIE_FREQ
, RTC_SAM7_BIT
},
58 /* Those are the bits from a classic RTC we want to mimic */
59 #define RTC_IRQF 0x80 /* any of the following 3 is active */
60 #define RTC_PF 0x40 /* Periodic interrupt */
61 #define RTC_AF 0x20 /* Alarm interrupt */
62 #define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */
64 #define MXC_RTC_TIME 0
65 #define MXC_RTC_ALARM 1
67 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
68 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
69 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
70 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
71 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
72 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
73 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
74 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
75 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
76 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
77 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
78 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
79 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
81 struct rtc_plat_data
{
82 struct rtc_device
*rtc
;
86 struct rtc_time g_rtc_alarm
;
90 * This function is used to obtain the RTC time or the alarm value in
93 static u32
get_alarm_or_time(struct device
*dev
, int time_alarm
)
95 struct platform_device
*pdev
= to_platform_device(dev
);
96 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
97 void __iomem
*ioaddr
= pdata
->ioaddr
;
98 u32 day
= 0, hr
= 0, min
= 0, sec
= 0, hr_min
= 0;
100 switch (time_alarm
) {
102 day
= readw(ioaddr
+ RTC_DAYR
);
103 hr_min
= readw(ioaddr
+ RTC_HOURMIN
);
104 sec
= readw(ioaddr
+ RTC_SECOND
);
107 day
= readw(ioaddr
+ RTC_DAYALARM
);
108 hr_min
= readw(ioaddr
+ RTC_ALRM_HM
) & 0xffff;
109 sec
= readw(ioaddr
+ RTC_ALRM_SEC
);
116 return (((day
* 24 + hr
) * 60) + min
) * 60 + sec
;
120 * This function sets the RTC alarm value or the time value.
122 static void set_alarm_or_time(struct device
*dev
, int time_alarm
, u32 time
)
124 u32 day
, hr
, min
, sec
, temp
;
125 struct platform_device
*pdev
= to_platform_device(dev
);
126 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
127 void __iomem
*ioaddr
= pdata
->ioaddr
;
132 /* time is within a day now */
136 /* time is within an hour now */
138 sec
= time
- min
* 60;
140 temp
= (hr
<< 8) + min
;
142 switch (time_alarm
) {
144 writew(day
, ioaddr
+ RTC_DAYR
);
145 writew(sec
, ioaddr
+ RTC_SECOND
);
146 writew(temp
, ioaddr
+ RTC_HOURMIN
);
149 writew(day
, ioaddr
+ RTC_DAYALARM
);
150 writew(sec
, ioaddr
+ RTC_ALRM_SEC
);
151 writew(temp
, ioaddr
+ RTC_ALRM_HM
);
157 * This function updates the RTC alarm registers and then clears all the
158 * interrupt status bits.
160 static int rtc_update_alarm(struct device
*dev
, struct rtc_time
*alrm
)
162 struct rtc_time alarm_tm
, now_tm
;
163 unsigned long now
, time
;
165 struct platform_device
*pdev
= to_platform_device(dev
);
166 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
167 void __iomem
*ioaddr
= pdata
->ioaddr
;
169 now
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
170 rtc_time_to_tm(now
, &now_tm
);
171 alarm_tm
.tm_year
= now_tm
.tm_year
;
172 alarm_tm
.tm_mon
= now_tm
.tm_mon
;
173 alarm_tm
.tm_mday
= now_tm
.tm_mday
;
174 alarm_tm
.tm_hour
= alrm
->tm_hour
;
175 alarm_tm
.tm_min
= alrm
->tm_min
;
176 alarm_tm
.tm_sec
= alrm
->tm_sec
;
177 rtc_tm_to_time(&now_tm
, &now
);
178 rtc_tm_to_time(&alarm_tm
, &time
);
181 time
+= 60 * 60 * 24;
182 rtc_time_to_tm(time
, &alarm_tm
);
185 ret
= rtc_tm_to_time(&alarm_tm
, &time
);
187 /* clear all the interrupt status bits */
188 writew(readw(ioaddr
+ RTC_RTCISR
), ioaddr
+ RTC_RTCISR
);
189 set_alarm_or_time(dev
, MXC_RTC_ALARM
, time
);
194 /* This function is the RTC interrupt service routine. */
195 static irqreturn_t
mxc_rtc_interrupt(int irq
, void *dev_id
)
197 struct platform_device
*pdev
= dev_id
;
198 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
199 void __iomem
*ioaddr
= pdata
->ioaddr
;
203 spin_lock_irq(&pdata
->rtc
->irq_lock
);
204 status
= readw(ioaddr
+ RTC_RTCISR
) & readw(ioaddr
+ RTC_RTCIENR
);
205 /* clear interrupt sources */
206 writew(status
, ioaddr
+ RTC_RTCISR
);
208 /* clear alarm interrupt if it has occurred */
209 if (status
& RTC_ALM_BIT
)
210 status
&= ~RTC_ALM_BIT
;
212 /* update irq data & counter */
213 if (status
& RTC_ALM_BIT
)
214 events
|= (RTC_AF
| RTC_IRQF
);
216 if (status
& RTC_1HZ_BIT
)
217 events
|= (RTC_UF
| RTC_IRQF
);
219 if (status
& PIT_ALL_ON
)
220 events
|= (RTC_PF
| RTC_IRQF
);
222 if ((status
& RTC_ALM_BIT
) && rtc_valid_tm(&pdata
->g_rtc_alarm
))
223 rtc_update_alarm(&pdev
->dev
, &pdata
->g_rtc_alarm
);
225 rtc_update_irq(pdata
->rtc
, 1, events
);
226 spin_unlock_irq(&pdata
->rtc
->irq_lock
);
232 * Clear all interrupts and release the IRQ
234 static void mxc_rtc_release(struct device
*dev
)
236 struct platform_device
*pdev
= to_platform_device(dev
);
237 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
238 void __iomem
*ioaddr
= pdata
->ioaddr
;
240 spin_lock_irq(&pdata
->rtc
->irq_lock
);
242 /* Disable all rtc interrupts */
243 writew(0, ioaddr
+ RTC_RTCIENR
);
245 /* Clear all interrupt status */
246 writew(0xffffffff, ioaddr
+ RTC_RTCISR
);
248 spin_unlock_irq(&pdata
->rtc
->irq_lock
);
251 static void mxc_rtc_irq_enable(struct device
*dev
, unsigned int bit
,
252 unsigned int enabled
)
254 struct platform_device
*pdev
= to_platform_device(dev
);
255 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
256 void __iomem
*ioaddr
= pdata
->ioaddr
;
259 spin_lock_irq(&pdata
->rtc
->irq_lock
);
260 reg
= readw(ioaddr
+ RTC_RTCIENR
);
267 writew(reg
, ioaddr
+ RTC_RTCIENR
);
268 spin_unlock_irq(&pdata
->rtc
->irq_lock
);
271 static int mxc_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
273 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, enabled
);
277 static int mxc_rtc_update_irq_enable(struct device
*dev
, unsigned int enabled
)
279 mxc_rtc_irq_enable(dev
, RTC_1HZ_BIT
, enabled
);
284 * This function reads the current RTC time into tm in Gregorian date.
286 static int mxc_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
290 /* Avoid roll-over from reading the different registers */
292 val
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
293 } while (val
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
295 rtc_time_to_tm(val
, tm
);
301 * This function sets the internal RTC time based on tm in Gregorian date.
303 static int mxc_rtc_set_mmss(struct device
*dev
, unsigned long time
)
305 /* Avoid roll-over from reading the different registers */
307 set_alarm_or_time(dev
, MXC_RTC_TIME
, time
);
308 } while (time
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
314 * This function reads the current alarm value into the passed in 'alrm'
315 * argument. It updates the alrm's pending field value based on the whether
316 * an alarm interrupt occurs or not.
318 static int mxc_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
320 struct platform_device
*pdev
= to_platform_device(dev
);
321 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
322 void __iomem
*ioaddr
= pdata
->ioaddr
;
324 rtc_time_to_tm(get_alarm_or_time(dev
, MXC_RTC_ALARM
), &alrm
->time
);
325 alrm
->pending
= ((readw(ioaddr
+ RTC_RTCISR
) & RTC_ALM_BIT
)) ? 1 : 0;
331 * This function sets the RTC alarm based on passed in alrm.
333 static int mxc_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
335 struct platform_device
*pdev
= to_platform_device(dev
);
336 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
339 if (rtc_valid_tm(&alrm
->time
)) {
340 if (alrm
->time
.tm_sec
> 59 ||
341 alrm
->time
.tm_hour
> 23 ||
342 alrm
->time
.tm_min
> 59)
345 ret
= rtc_update_alarm(dev
, &alrm
->time
);
347 ret
= rtc_valid_tm(&alrm
->time
);
351 ret
= rtc_update_alarm(dev
, &alrm
->time
);
357 memcpy(&pdata
->g_rtc_alarm
, &alrm
->time
, sizeof(struct rtc_time
));
358 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, alrm
->enabled
);
364 static struct rtc_class_ops mxc_rtc_ops
= {
365 .release
= mxc_rtc_release
,
366 .read_time
= mxc_rtc_read_time
,
367 .set_mmss
= mxc_rtc_set_mmss
,
368 .read_alarm
= mxc_rtc_read_alarm
,
369 .set_alarm
= mxc_rtc_set_alarm
,
370 .alarm_irq_enable
= mxc_rtc_alarm_irq_enable
,
371 .update_irq_enable
= mxc_rtc_update_irq_enable
,
374 static int __init
mxc_rtc_probe(struct platform_device
*pdev
)
376 struct resource
*res
;
377 struct rtc_device
*rtc
;
378 struct rtc_plat_data
*pdata
= NULL
;
383 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
387 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
391 if (!devm_request_mem_region(&pdev
->dev
, res
->start
,
392 resource_size(res
), pdev
->name
))
395 pdata
->ioaddr
= devm_ioremap(&pdev
->dev
, res
->start
,
398 pdata
->clk
= clk_get(&pdev
->dev
, "rtc");
399 if (IS_ERR(pdata
->clk
)) {
400 dev_err(&pdev
->dev
, "unable to get clock!\n");
401 ret
= PTR_ERR(pdata
->clk
);
402 goto exit_free_pdata
;
405 clk_enable(pdata
->clk
);
406 rate
= clk_get_rate(pdata
->clk
);
409 reg
= RTC_INPUT_CLK_32768HZ
;
410 else if (rate
== 32000)
411 reg
= RTC_INPUT_CLK_32000HZ
;
412 else if (rate
== 38400)
413 reg
= RTC_INPUT_CLK_38400HZ
;
415 dev_err(&pdev
->dev
, "rtc clock is not valid (%lu)\n", rate
);
420 reg
|= RTC_ENABLE_BIT
;
421 writew(reg
, (pdata
->ioaddr
+ RTC_RTCCTL
));
422 if (((readw(pdata
->ioaddr
+ RTC_RTCCTL
)) & RTC_ENABLE_BIT
) == 0) {
423 dev_err(&pdev
->dev
, "hardware module can't be enabled!\n");
428 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
, &mxc_rtc_ops
,
436 platform_set_drvdata(pdev
, pdata
);
438 /* Configure and enable the RTC */
439 pdata
->irq
= platform_get_irq(pdev
, 0);
441 if (pdata
->irq
>= 0 &&
442 devm_request_irq(&pdev
->dev
, pdata
->irq
, mxc_rtc_interrupt
,
443 IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
444 dev_warn(&pdev
->dev
, "interrupt not available.\n");
451 clk_disable(pdata
->clk
);
459 static int __exit
mxc_rtc_remove(struct platform_device
*pdev
)
461 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
463 rtc_device_unregister(pdata
->rtc
);
465 clk_disable(pdata
->clk
);
467 platform_set_drvdata(pdev
, NULL
);
472 static struct platform_driver mxc_rtc_driver
= {
475 .owner
= THIS_MODULE
,
477 .remove
= __exit_p(mxc_rtc_remove
),
480 static int __init
mxc_rtc_init(void)
482 return platform_driver_probe(&mxc_rtc_driver
, mxc_rtc_probe
);
485 static void __exit
mxc_rtc_exit(void)
487 platform_driver_unregister(&mxc_rtc_driver
);
490 module_init(mxc_rtc_init
);
491 module_exit(mxc_rtc_exit
);
493 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
494 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
495 MODULE_LICENSE("GPL");