1 // SPDX-License-Identifier: GPL-2.0+
3 // Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_wakeirq.h>
12 #include <linux/clk.h>
14 #include <linux/of_device.h>
16 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
17 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
18 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
20 #define RTC_SW_BIT (1 << 0)
21 #define RTC_ALM_BIT (1 << 2)
22 #define RTC_1HZ_BIT (1 << 4)
23 #define RTC_2HZ_BIT (1 << 7)
24 #define RTC_SAM0_BIT (1 << 8)
25 #define RTC_SAM1_BIT (1 << 9)
26 #define RTC_SAM2_BIT (1 << 10)
27 #define RTC_SAM3_BIT (1 << 11)
28 #define RTC_SAM4_BIT (1 << 12)
29 #define RTC_SAM5_BIT (1 << 13)
30 #define RTC_SAM6_BIT (1 << 14)
31 #define RTC_SAM7_BIT (1 << 15)
32 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
33 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
34 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
36 #define RTC_ENABLE_BIT (1 << 7)
39 #define MAX_PIE_FREQ 512
41 #define MXC_RTC_TIME 0
42 #define MXC_RTC_ALARM 1
44 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
45 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
46 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
47 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
48 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
49 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
50 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
51 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
52 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
53 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
54 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
55 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
56 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
63 struct rtc_plat_data
{
64 struct rtc_device
*rtc
;
69 struct rtc_time g_rtc_alarm
;
70 enum imx_rtc_type devtype
;
73 static const struct platform_device_id imx_rtc_devtype
[] = {
76 .driver_data
= IMX1_RTC
,
79 .driver_data
= IMX21_RTC
,
84 MODULE_DEVICE_TABLE(platform
, imx_rtc_devtype
);
87 static const struct of_device_id imx_rtc_dt_ids
[] = {
88 { .compatible
= "fsl,imx1-rtc", .data
= (const void *)IMX1_RTC
},
89 { .compatible
= "fsl,imx21-rtc", .data
= (const void *)IMX21_RTC
},
92 MODULE_DEVICE_TABLE(of
, imx_rtc_dt_ids
);
95 static inline int is_imx1_rtc(struct rtc_plat_data
*data
)
97 return data
->devtype
== IMX1_RTC
;
101 * This function is used to obtain the RTC time or the alarm value in
104 static time64_t
get_alarm_or_time(struct device
*dev
, int time_alarm
)
106 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
107 void __iomem
*ioaddr
= pdata
->ioaddr
;
108 u32 day
= 0, hr
= 0, min
= 0, sec
= 0, hr_min
= 0;
110 switch (time_alarm
) {
112 day
= readw(ioaddr
+ RTC_DAYR
);
113 hr_min
= readw(ioaddr
+ RTC_HOURMIN
);
114 sec
= readw(ioaddr
+ RTC_SECOND
);
117 day
= readw(ioaddr
+ RTC_DAYALARM
);
118 hr_min
= readw(ioaddr
+ RTC_ALRM_HM
) & 0xffff;
119 sec
= readw(ioaddr
+ RTC_ALRM_SEC
);
126 return ((((time64_t
)day
* 24 + hr
) * 60) + min
) * 60 + sec
;
130 * This function sets the RTC alarm value or the time value.
132 static void set_alarm_or_time(struct device
*dev
, int time_alarm
, time64_t time
)
134 u32 tod
, day
, hr
, min
, sec
, temp
;
135 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
136 void __iomem
*ioaddr
= pdata
->ioaddr
;
138 day
= div_s64_rem(time
, 86400, &tod
);
140 /* time is within a day now */
144 /* time is within an hour now */
146 sec
= tod
- min
* 60;
148 temp
= (hr
<< 8) + min
;
150 switch (time_alarm
) {
152 writew(day
, ioaddr
+ RTC_DAYR
);
153 writew(sec
, ioaddr
+ RTC_SECOND
);
154 writew(temp
, ioaddr
+ RTC_HOURMIN
);
157 writew(day
, ioaddr
+ RTC_DAYALARM
);
158 writew(sec
, ioaddr
+ RTC_ALRM_SEC
);
159 writew(temp
, ioaddr
+ RTC_ALRM_HM
);
165 * This function updates the RTC alarm registers and then clears all the
166 * interrupt status bits.
168 static void rtc_update_alarm(struct device
*dev
, struct rtc_time
*alrm
)
171 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
172 void __iomem
*ioaddr
= pdata
->ioaddr
;
174 time
= rtc_tm_to_time64(alrm
);
176 /* clear all the interrupt status bits */
177 writew(readw(ioaddr
+ RTC_RTCISR
), ioaddr
+ RTC_RTCISR
);
178 set_alarm_or_time(dev
, MXC_RTC_ALARM
, time
);
181 static void mxc_rtc_irq_enable(struct device
*dev
, unsigned int bit
,
182 unsigned int enabled
)
184 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
185 void __iomem
*ioaddr
= pdata
->ioaddr
;
189 spin_lock_irqsave(&pdata
->rtc
->irq_lock
, flags
);
190 reg
= readw(ioaddr
+ RTC_RTCIENR
);
197 writew(reg
, ioaddr
+ RTC_RTCIENR
);
198 spin_unlock_irqrestore(&pdata
->rtc
->irq_lock
, flags
);
201 /* This function is the RTC interrupt service routine. */
202 static irqreturn_t
mxc_rtc_interrupt(int irq
, void *dev_id
)
204 struct platform_device
*pdev
= dev_id
;
205 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
206 void __iomem
*ioaddr
= pdata
->ioaddr
;
211 spin_lock_irqsave(&pdata
->rtc
->irq_lock
, flags
);
212 status
= readw(ioaddr
+ RTC_RTCISR
) & readw(ioaddr
+ RTC_RTCIENR
);
213 /* clear interrupt sources */
214 writew(status
, ioaddr
+ RTC_RTCISR
);
216 /* update irq data & counter */
217 if (status
& RTC_ALM_BIT
) {
218 events
|= (RTC_AF
| RTC_IRQF
);
219 /* RTC alarm should be one-shot */
220 mxc_rtc_irq_enable(&pdev
->dev
, RTC_ALM_BIT
, 0);
223 if (status
& PIT_ALL_ON
)
224 events
|= (RTC_PF
| RTC_IRQF
);
226 rtc_update_irq(pdata
->rtc
, 1, events
);
227 spin_unlock_irqrestore(&pdata
->rtc
->irq_lock
, flags
);
232 static int mxc_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
234 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, enabled
);
239 * This function reads the current RTC time into tm in Gregorian date.
241 static int mxc_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
245 /* Avoid roll-over from reading the different registers */
247 val
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
248 } while (val
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
250 rtc_time64_to_tm(val
, tm
);
256 * This function sets the internal RTC time based on tm in Gregorian date.
258 static int mxc_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
260 time64_t time
= rtc_tm_to_time64(tm
);
262 /* Avoid roll-over from reading the different registers */
264 set_alarm_or_time(dev
, MXC_RTC_TIME
, time
);
265 } while (time
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
271 * This function reads the current alarm value into the passed in 'alrm'
272 * argument. It updates the alrm's pending field value based on the whether
273 * an alarm interrupt occurs or not.
275 static int mxc_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
277 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
278 void __iomem
*ioaddr
= pdata
->ioaddr
;
280 rtc_time64_to_tm(get_alarm_or_time(dev
, MXC_RTC_ALARM
), &alrm
->time
);
281 alrm
->pending
= ((readw(ioaddr
+ RTC_RTCISR
) & RTC_ALM_BIT
)) ? 1 : 0;
287 * This function sets the RTC alarm based on passed in alrm.
289 static int mxc_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
291 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
293 rtc_update_alarm(dev
, &alrm
->time
);
295 memcpy(&pdata
->g_rtc_alarm
, &alrm
->time
, sizeof(struct rtc_time
));
296 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, alrm
->enabled
);
302 static const struct rtc_class_ops mxc_rtc_ops
= {
303 .read_time
= mxc_rtc_read_time
,
304 .set_time
= mxc_rtc_set_time
,
305 .read_alarm
= mxc_rtc_read_alarm
,
306 .set_alarm
= mxc_rtc_set_alarm
,
307 .alarm_irq_enable
= mxc_rtc_alarm_irq_enable
,
310 static void mxc_rtc_action(void *p
)
312 struct rtc_plat_data
*pdata
= p
;
314 clk_disable_unprepare(pdata
->clk_ref
);
315 clk_disable_unprepare(pdata
->clk_ipg
);
318 static int mxc_rtc_probe(struct platform_device
*pdev
)
320 struct rtc_device
*rtc
;
321 struct rtc_plat_data
*pdata
= NULL
;
325 const struct of_device_id
*of_id
;
327 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
331 of_id
= of_match_device(imx_rtc_dt_ids
, &pdev
->dev
);
333 pdata
->devtype
= (enum imx_rtc_type
)of_id
->data
;
335 pdata
->devtype
= pdev
->id_entry
->driver_data
;
337 pdata
->ioaddr
= devm_platform_ioremap_resource(pdev
, 0);
338 if (IS_ERR(pdata
->ioaddr
))
339 return PTR_ERR(pdata
->ioaddr
);
341 rtc
= devm_rtc_allocate_device(&pdev
->dev
);
346 rtc
->ops
= &mxc_rtc_ops
;
347 if (is_imx1_rtc(pdata
)) {
350 /* 9bit days + hours minutes seconds */
351 rtc
->range_max
= (1 << 9) * 86400 - 1;
354 * Set the start date as beginning of the current year. This can
355 * be overridden using device tree.
357 rtc_time64_to_tm(ktime_get_real_seconds(), &tm
);
358 rtc
->start_secs
= mktime64(tm
.tm_year
, 1, 1, 0, 0, 0);
359 rtc
->set_start_time
= true;
361 /* 16bit days + hours minutes seconds */
362 rtc
->range_max
= (1 << 16) * 86400ULL - 1;
365 pdata
->clk_ipg
= devm_clk_get(&pdev
->dev
, "ipg");
366 if (IS_ERR(pdata
->clk_ipg
)) {
367 dev_err(&pdev
->dev
, "unable to get ipg clock!\n");
368 return PTR_ERR(pdata
->clk_ipg
);
371 ret
= clk_prepare_enable(pdata
->clk_ipg
);
375 pdata
->clk_ref
= devm_clk_get(&pdev
->dev
, "ref");
376 if (IS_ERR(pdata
->clk_ref
)) {
377 clk_disable_unprepare(pdata
->clk_ipg
);
378 dev_err(&pdev
->dev
, "unable to get ref clock!\n");
379 return PTR_ERR(pdata
->clk_ref
);
382 ret
= clk_prepare_enable(pdata
->clk_ref
);
384 clk_disable_unprepare(pdata
->clk_ipg
);
388 ret
= devm_add_action_or_reset(&pdev
->dev
, mxc_rtc_action
, pdata
);
392 rate
= clk_get_rate(pdata
->clk_ref
);
395 reg
= RTC_INPUT_CLK_32768HZ
;
396 else if (rate
== 32000)
397 reg
= RTC_INPUT_CLK_32000HZ
;
398 else if (rate
== 38400)
399 reg
= RTC_INPUT_CLK_38400HZ
;
401 dev_err(&pdev
->dev
, "rtc clock is not valid (%lu)\n", rate
);
405 reg
|= RTC_ENABLE_BIT
;
406 writew(reg
, (pdata
->ioaddr
+ RTC_RTCCTL
));
407 if (((readw(pdata
->ioaddr
+ RTC_RTCCTL
)) & RTC_ENABLE_BIT
) == 0) {
408 dev_err(&pdev
->dev
, "hardware module can't be enabled!\n");
412 platform_set_drvdata(pdev
, pdata
);
414 /* Configure and enable the RTC */
415 pdata
->irq
= platform_get_irq(pdev
, 0);
417 if (pdata
->irq
>= 0 &&
418 devm_request_irq(&pdev
->dev
, pdata
->irq
, mxc_rtc_interrupt
,
419 IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
420 dev_warn(&pdev
->dev
, "interrupt not available.\n");
424 if (pdata
->irq
>= 0) {
425 device_init_wakeup(&pdev
->dev
, 1);
426 ret
= dev_pm_set_wake_irq(&pdev
->dev
, pdata
->irq
);
428 dev_err(&pdev
->dev
, "failed to enable irq wake\n");
431 ret
= rtc_register_device(rtc
);
436 static struct platform_driver mxc_rtc_driver
= {
439 .of_match_table
= of_match_ptr(imx_rtc_dt_ids
),
441 .id_table
= imx_rtc_devtype
,
442 .probe
= mxc_rtc_probe
,
445 module_platform_driver(mxc_rtc_driver
)
447 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
448 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
449 MODULE_LICENSE("GPL");