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 #define MXC_RTC_TIME 0
59 #define MXC_RTC_ALARM 1
61 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
62 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
63 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
64 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
65 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
66 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
67 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
68 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
69 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
70 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
71 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
72 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
73 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
75 struct rtc_plat_data
{
76 struct rtc_device
*rtc
;
80 struct rtc_time g_rtc_alarm
;
84 * This function is used to obtain the RTC time or the alarm value in
87 static u32
get_alarm_or_time(struct device
*dev
, int time_alarm
)
89 struct platform_device
*pdev
= to_platform_device(dev
);
90 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
91 void __iomem
*ioaddr
= pdata
->ioaddr
;
92 u32 day
= 0, hr
= 0, min
= 0, sec
= 0, hr_min
= 0;
96 day
= readw(ioaddr
+ RTC_DAYR
);
97 hr_min
= readw(ioaddr
+ RTC_HOURMIN
);
98 sec
= readw(ioaddr
+ RTC_SECOND
);
101 day
= readw(ioaddr
+ RTC_DAYALARM
);
102 hr_min
= readw(ioaddr
+ RTC_ALRM_HM
) & 0xffff;
103 sec
= readw(ioaddr
+ RTC_ALRM_SEC
);
110 return (((day
* 24 + hr
) * 60) + min
) * 60 + sec
;
114 * This function sets the RTC alarm value or the time value.
116 static void set_alarm_or_time(struct device
*dev
, int time_alarm
, u32 time
)
118 u32 day
, hr
, min
, sec
, temp
;
119 struct platform_device
*pdev
= to_platform_device(dev
);
120 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
121 void __iomem
*ioaddr
= pdata
->ioaddr
;
126 /* time is within a day now */
130 /* time is within an hour now */
132 sec
= time
- min
* 60;
134 temp
= (hr
<< 8) + min
;
136 switch (time_alarm
) {
138 writew(day
, ioaddr
+ RTC_DAYR
);
139 writew(sec
, ioaddr
+ RTC_SECOND
);
140 writew(temp
, ioaddr
+ RTC_HOURMIN
);
143 writew(day
, ioaddr
+ RTC_DAYALARM
);
144 writew(sec
, ioaddr
+ RTC_ALRM_SEC
);
145 writew(temp
, ioaddr
+ RTC_ALRM_HM
);
151 * This function updates the RTC alarm registers and then clears all the
152 * interrupt status bits.
154 static int rtc_update_alarm(struct device
*dev
, struct rtc_time
*alrm
)
156 struct rtc_time alarm_tm
, now_tm
;
157 unsigned long now
, time
;
159 struct platform_device
*pdev
= to_platform_device(dev
);
160 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
161 void __iomem
*ioaddr
= pdata
->ioaddr
;
163 now
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
164 rtc_time_to_tm(now
, &now_tm
);
165 alarm_tm
.tm_year
= now_tm
.tm_year
;
166 alarm_tm
.tm_mon
= now_tm
.tm_mon
;
167 alarm_tm
.tm_mday
= now_tm
.tm_mday
;
168 alarm_tm
.tm_hour
= alrm
->tm_hour
;
169 alarm_tm
.tm_min
= alrm
->tm_min
;
170 alarm_tm
.tm_sec
= alrm
->tm_sec
;
171 rtc_tm_to_time(&now_tm
, &now
);
172 rtc_tm_to_time(&alarm_tm
, &time
);
175 time
+= 60 * 60 * 24;
176 rtc_time_to_tm(time
, &alarm_tm
);
179 ret
= rtc_tm_to_time(&alarm_tm
, &time
);
181 /* clear all the interrupt status bits */
182 writew(readw(ioaddr
+ RTC_RTCISR
), ioaddr
+ RTC_RTCISR
);
183 set_alarm_or_time(dev
, MXC_RTC_ALARM
, time
);
188 /* This function is the RTC interrupt service routine. */
189 static irqreturn_t
mxc_rtc_interrupt(int irq
, void *dev_id
)
191 struct platform_device
*pdev
= dev_id
;
192 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
193 void __iomem
*ioaddr
= pdata
->ioaddr
;
198 spin_lock_irqsave(&pdata
->rtc
->irq_lock
, flags
);
199 status
= readw(ioaddr
+ RTC_RTCISR
) & readw(ioaddr
+ RTC_RTCIENR
);
200 /* clear interrupt sources */
201 writew(status
, ioaddr
+ RTC_RTCISR
);
203 /* clear alarm interrupt if it has occurred */
204 if (status
& RTC_ALM_BIT
)
205 status
&= ~RTC_ALM_BIT
;
207 /* update irq data & counter */
208 if (status
& RTC_ALM_BIT
)
209 events
|= (RTC_AF
| RTC_IRQF
);
211 if (status
& RTC_1HZ_BIT
)
212 events
|= (RTC_UF
| RTC_IRQF
);
214 if (status
& PIT_ALL_ON
)
215 events
|= (RTC_PF
| RTC_IRQF
);
217 if ((status
& RTC_ALM_BIT
) && rtc_valid_tm(&pdata
->g_rtc_alarm
))
218 rtc_update_alarm(&pdev
->dev
, &pdata
->g_rtc_alarm
);
220 rtc_update_irq(pdata
->rtc
, 1, events
);
221 spin_unlock_irqrestore(&pdata
->rtc
->irq_lock
, flags
);
227 * Clear all interrupts and release the IRQ
229 static void mxc_rtc_release(struct device
*dev
)
231 struct platform_device
*pdev
= to_platform_device(dev
);
232 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
233 void __iomem
*ioaddr
= pdata
->ioaddr
;
235 spin_lock_irq(&pdata
->rtc
->irq_lock
);
237 /* Disable all rtc interrupts */
238 writew(0, ioaddr
+ RTC_RTCIENR
);
240 /* Clear all interrupt status */
241 writew(0xffffffff, ioaddr
+ RTC_RTCISR
);
243 spin_unlock_irq(&pdata
->rtc
->irq_lock
);
246 static void mxc_rtc_irq_enable(struct device
*dev
, unsigned int bit
,
247 unsigned int enabled
)
249 struct platform_device
*pdev
= to_platform_device(dev
);
250 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
251 void __iomem
*ioaddr
= pdata
->ioaddr
;
254 spin_lock_irq(&pdata
->rtc
->irq_lock
);
255 reg
= readw(ioaddr
+ RTC_RTCIENR
);
262 writew(reg
, ioaddr
+ RTC_RTCIENR
);
263 spin_unlock_irq(&pdata
->rtc
->irq_lock
);
266 static int mxc_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
268 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, enabled
);
273 * This function reads the current RTC time into tm in Gregorian date.
275 static int mxc_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
279 /* Avoid roll-over from reading the different registers */
281 val
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
282 } while (val
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
284 rtc_time_to_tm(val
, tm
);
290 * This function sets the internal RTC time based on tm in Gregorian date.
292 static int mxc_rtc_set_mmss(struct device
*dev
, unsigned long time
)
294 /* Avoid roll-over from reading the different registers */
296 set_alarm_or_time(dev
, MXC_RTC_TIME
, time
);
297 } while (time
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
303 * This function reads the current alarm value into the passed in 'alrm'
304 * argument. It updates the alrm's pending field value based on the whether
305 * an alarm interrupt occurs or not.
307 static int mxc_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
309 struct platform_device
*pdev
= to_platform_device(dev
);
310 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
311 void __iomem
*ioaddr
= pdata
->ioaddr
;
313 rtc_time_to_tm(get_alarm_or_time(dev
, MXC_RTC_ALARM
), &alrm
->time
);
314 alrm
->pending
= ((readw(ioaddr
+ RTC_RTCISR
) & RTC_ALM_BIT
)) ? 1 : 0;
320 * This function sets the RTC alarm based on passed in alrm.
322 static int mxc_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
324 struct platform_device
*pdev
= to_platform_device(dev
);
325 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
328 if (rtc_valid_tm(&alrm
->time
)) {
329 if (alrm
->time
.tm_sec
> 59 ||
330 alrm
->time
.tm_hour
> 23 ||
331 alrm
->time
.tm_min
> 59)
334 ret
= rtc_update_alarm(dev
, &alrm
->time
);
336 ret
= rtc_valid_tm(&alrm
->time
);
340 ret
= rtc_update_alarm(dev
, &alrm
->time
);
346 memcpy(&pdata
->g_rtc_alarm
, &alrm
->time
, sizeof(struct rtc_time
));
347 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, alrm
->enabled
);
353 static struct rtc_class_ops mxc_rtc_ops
= {
354 .release
= mxc_rtc_release
,
355 .read_time
= mxc_rtc_read_time
,
356 .set_mmss
= mxc_rtc_set_mmss
,
357 .read_alarm
= mxc_rtc_read_alarm
,
358 .set_alarm
= mxc_rtc_set_alarm
,
359 .alarm_irq_enable
= mxc_rtc_alarm_irq_enable
,
362 static int __init
mxc_rtc_probe(struct platform_device
*pdev
)
364 struct resource
*res
;
365 struct rtc_device
*rtc
;
366 struct rtc_plat_data
*pdata
= NULL
;
371 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
375 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
379 if (!devm_request_mem_region(&pdev
->dev
, res
->start
,
380 resource_size(res
), pdev
->name
))
383 pdata
->ioaddr
= devm_ioremap(&pdev
->dev
, res
->start
,
386 pdata
->clk
= clk_get(&pdev
->dev
, "rtc");
387 if (IS_ERR(pdata
->clk
)) {
388 dev_err(&pdev
->dev
, "unable to get clock!\n");
389 ret
= PTR_ERR(pdata
->clk
);
390 goto exit_free_pdata
;
393 clk_enable(pdata
->clk
);
394 rate
= clk_get_rate(pdata
->clk
);
397 reg
= RTC_INPUT_CLK_32768HZ
;
398 else if (rate
== 32000)
399 reg
= RTC_INPUT_CLK_32000HZ
;
400 else if (rate
== 38400)
401 reg
= RTC_INPUT_CLK_38400HZ
;
403 dev_err(&pdev
->dev
, "rtc clock is not valid (%lu)\n", rate
);
408 reg
|= RTC_ENABLE_BIT
;
409 writew(reg
, (pdata
->ioaddr
+ RTC_RTCCTL
));
410 if (((readw(pdata
->ioaddr
+ RTC_RTCCTL
)) & RTC_ENABLE_BIT
) == 0) {
411 dev_err(&pdev
->dev
, "hardware module can't be enabled!\n");
416 platform_set_drvdata(pdev
, pdata
);
418 /* Configure and enable the RTC */
419 pdata
->irq
= platform_get_irq(pdev
, 0);
421 if (pdata
->irq
>= 0 &&
422 devm_request_irq(&pdev
->dev
, pdata
->irq
, mxc_rtc_interrupt
,
423 IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
424 dev_warn(&pdev
->dev
, "interrupt not available.\n");
428 rtc
= rtc_device_register(pdev
->name
, &pdev
->dev
, &mxc_rtc_ops
,
432 goto exit_clr_drvdata
;
440 platform_set_drvdata(pdev
, NULL
);
442 clk_disable(pdata
->clk
);
450 static int __exit
mxc_rtc_remove(struct platform_device
*pdev
)
452 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
454 rtc_device_unregister(pdata
->rtc
);
456 clk_disable(pdata
->clk
);
458 platform_set_drvdata(pdev
, NULL
);
463 static struct platform_driver mxc_rtc_driver
= {
466 .owner
= THIS_MODULE
,
468 .remove
= __exit_p(mxc_rtc_remove
),
471 static int __init
mxc_rtc_init(void)
473 return platform_driver_probe(&mxc_rtc_driver
, mxc_rtc_probe
);
476 static void __exit
mxc_rtc_exit(void)
478 platform_driver_unregister(&mxc_rtc_driver
);
481 module_init(mxc_rtc_init
);
482 module_exit(mxc_rtc_exit
);
484 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
485 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
486 MODULE_LICENSE("GPL");