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>
15 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
16 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
17 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
19 #define RTC_SW_BIT (1 << 0)
20 #define RTC_ALM_BIT (1 << 2)
21 #define RTC_1HZ_BIT (1 << 4)
22 #define RTC_2HZ_BIT (1 << 7)
23 #define RTC_SAM0_BIT (1 << 8)
24 #define RTC_SAM1_BIT (1 << 9)
25 #define RTC_SAM2_BIT (1 << 10)
26 #define RTC_SAM3_BIT (1 << 11)
27 #define RTC_SAM4_BIT (1 << 12)
28 #define RTC_SAM5_BIT (1 << 13)
29 #define RTC_SAM6_BIT (1 << 14)
30 #define RTC_SAM7_BIT (1 << 15)
31 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
32 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
33 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
35 #define RTC_ENABLE_BIT (1 << 7)
38 #define MAX_PIE_FREQ 512
40 #define MXC_RTC_TIME 0
41 #define MXC_RTC_ALARM 1
43 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
44 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
45 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
46 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
47 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
48 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
49 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
50 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
51 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
52 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
53 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
54 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
55 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
62 struct rtc_plat_data
{
63 struct rtc_device
*rtc
;
68 struct rtc_time g_rtc_alarm
;
69 enum imx_rtc_type devtype
;
72 static const struct of_device_id imx_rtc_dt_ids
[] = {
73 { .compatible
= "fsl,imx1-rtc", .data
= (const void *)IMX1_RTC
},
74 { .compatible
= "fsl,imx21-rtc", .data
= (const void *)IMX21_RTC
},
77 MODULE_DEVICE_TABLE(of
, imx_rtc_dt_ids
);
79 static inline int is_imx1_rtc(struct rtc_plat_data
*data
)
81 return data
->devtype
== IMX1_RTC
;
85 * This function is used to obtain the RTC time or the alarm value in
88 static time64_t
get_alarm_or_time(struct device
*dev
, int time_alarm
)
90 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
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 ((((time64_t
)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
, time64_t time
)
118 u32 tod
, day
, hr
, min
, sec
, temp
;
119 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
120 void __iomem
*ioaddr
= pdata
->ioaddr
;
122 day
= div_s64_rem(time
, 86400, &tod
);
124 /* time is within a day now */
128 /* time is within an hour now */
130 sec
= tod
- min
* 60;
132 temp
= (hr
<< 8) + min
;
134 switch (time_alarm
) {
136 writew(day
, ioaddr
+ RTC_DAYR
);
137 writew(sec
, ioaddr
+ RTC_SECOND
);
138 writew(temp
, ioaddr
+ RTC_HOURMIN
);
141 writew(day
, ioaddr
+ RTC_DAYALARM
);
142 writew(sec
, ioaddr
+ RTC_ALRM_SEC
);
143 writew(temp
, ioaddr
+ RTC_ALRM_HM
);
149 * This function updates the RTC alarm registers and then clears all the
150 * interrupt status bits.
152 static void rtc_update_alarm(struct device
*dev
, struct rtc_time
*alrm
)
155 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
156 void __iomem
*ioaddr
= pdata
->ioaddr
;
158 time
= rtc_tm_to_time64(alrm
);
160 /* clear all the interrupt status bits */
161 writew(readw(ioaddr
+ RTC_RTCISR
), ioaddr
+ RTC_RTCISR
);
162 set_alarm_or_time(dev
, MXC_RTC_ALARM
, time
);
165 static void mxc_rtc_irq_enable(struct device
*dev
, unsigned int bit
,
166 unsigned int enabled
)
168 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
169 void __iomem
*ioaddr
= pdata
->ioaddr
;
173 spin_lock_irqsave(&pdata
->rtc
->irq_lock
, flags
);
174 reg
= readw(ioaddr
+ RTC_RTCIENR
);
181 writew(reg
, ioaddr
+ RTC_RTCIENR
);
182 spin_unlock_irqrestore(&pdata
->rtc
->irq_lock
, flags
);
185 /* This function is the RTC interrupt service routine. */
186 static irqreturn_t
mxc_rtc_interrupt(int irq
, void *dev_id
)
188 struct platform_device
*pdev
= dev_id
;
189 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
190 void __iomem
*ioaddr
= pdata
->ioaddr
;
194 spin_lock(&pdata
->rtc
->irq_lock
);
195 status
= readw(ioaddr
+ RTC_RTCISR
) & readw(ioaddr
+ RTC_RTCIENR
);
196 /* clear interrupt sources */
197 writew(status
, ioaddr
+ RTC_RTCISR
);
199 /* update irq data & counter */
200 if (status
& RTC_ALM_BIT
) {
201 events
|= (RTC_AF
| RTC_IRQF
);
202 /* RTC alarm should be one-shot */
203 mxc_rtc_irq_enable(&pdev
->dev
, RTC_ALM_BIT
, 0);
206 if (status
& PIT_ALL_ON
)
207 events
|= (RTC_PF
| RTC_IRQF
);
209 rtc_update_irq(pdata
->rtc
, 1, events
);
210 spin_unlock(&pdata
->rtc
->irq_lock
);
215 static int mxc_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
217 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, enabled
);
222 * This function reads the current RTC time into tm in Gregorian date.
224 static int mxc_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
228 /* Avoid roll-over from reading the different registers */
230 val
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
231 } while (val
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
233 rtc_time64_to_tm(val
, tm
);
239 * This function sets the internal RTC time based on tm in Gregorian date.
241 static int mxc_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
243 time64_t time
= rtc_tm_to_time64(tm
);
245 /* Avoid roll-over from reading the different registers */
247 set_alarm_or_time(dev
, MXC_RTC_TIME
, time
);
248 } while (time
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
254 * This function reads the current alarm value into the passed in 'alrm'
255 * argument. It updates the alrm's pending field value based on the whether
256 * an alarm interrupt occurs or not.
258 static int mxc_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
260 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
261 void __iomem
*ioaddr
= pdata
->ioaddr
;
263 rtc_time64_to_tm(get_alarm_or_time(dev
, MXC_RTC_ALARM
), &alrm
->time
);
264 alrm
->pending
= ((readw(ioaddr
+ RTC_RTCISR
) & RTC_ALM_BIT
)) ? 1 : 0;
270 * This function sets the RTC alarm based on passed in alrm.
272 static int mxc_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
274 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
276 rtc_update_alarm(dev
, &alrm
->time
);
278 memcpy(&pdata
->g_rtc_alarm
, &alrm
->time
, sizeof(struct rtc_time
));
279 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, alrm
->enabled
);
285 static const struct rtc_class_ops mxc_rtc_ops
= {
286 .read_time
= mxc_rtc_read_time
,
287 .set_time
= mxc_rtc_set_time
,
288 .read_alarm
= mxc_rtc_read_alarm
,
289 .set_alarm
= mxc_rtc_set_alarm
,
290 .alarm_irq_enable
= mxc_rtc_alarm_irq_enable
,
293 static int mxc_rtc_probe(struct platform_device
*pdev
)
295 struct rtc_device
*rtc
;
296 struct rtc_plat_data
*pdata
= NULL
;
301 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
305 pdata
->devtype
= (uintptr_t)of_device_get_match_data(&pdev
->dev
);
307 pdata
->ioaddr
= devm_platform_ioremap_resource(pdev
, 0);
308 if (IS_ERR(pdata
->ioaddr
))
309 return PTR_ERR(pdata
->ioaddr
);
311 rtc
= devm_rtc_allocate_device(&pdev
->dev
);
316 rtc
->ops
= &mxc_rtc_ops
;
317 if (is_imx1_rtc(pdata
)) {
320 /* 9bit days + hours minutes seconds */
321 rtc
->range_max
= (1 << 9) * 86400 - 1;
324 * Set the start date as beginning of the current year. This can
325 * be overridden using device tree.
327 rtc_time64_to_tm(ktime_get_real_seconds(), &tm
);
328 rtc
->start_secs
= mktime64(tm
.tm_year
, 1, 1, 0, 0, 0);
329 rtc
->set_start_time
= true;
331 /* 16bit days + hours minutes seconds */
332 rtc
->range_max
= (1 << 16) * 86400ULL - 1;
335 pdata
->clk_ipg
= devm_clk_get_enabled(&pdev
->dev
, "ipg");
336 if (IS_ERR(pdata
->clk_ipg
)) {
337 dev_err(&pdev
->dev
, "unable to get ipg clock!\n");
338 return PTR_ERR(pdata
->clk_ipg
);
341 pdata
->clk_ref
= devm_clk_get_enabled(&pdev
->dev
, "ref");
342 if (IS_ERR(pdata
->clk_ref
)) {
343 dev_err(&pdev
->dev
, "unable to get ref clock!\n");
344 return PTR_ERR(pdata
->clk_ref
);
347 rate
= clk_get_rate(pdata
->clk_ref
);
350 reg
= RTC_INPUT_CLK_32768HZ
;
351 else if (rate
== 32000)
352 reg
= RTC_INPUT_CLK_32000HZ
;
353 else if (rate
== 38400)
354 reg
= RTC_INPUT_CLK_38400HZ
;
356 dev_err(&pdev
->dev
, "rtc clock is not valid (%lu)\n", rate
);
360 reg
|= RTC_ENABLE_BIT
;
361 writew(reg
, (pdata
->ioaddr
+ RTC_RTCCTL
));
362 if (((readw(pdata
->ioaddr
+ RTC_RTCCTL
)) & RTC_ENABLE_BIT
) == 0) {
363 dev_err(&pdev
->dev
, "hardware module can't be enabled!\n");
367 platform_set_drvdata(pdev
, pdata
);
369 /* Configure and enable the RTC */
370 pdata
->irq
= platform_get_irq(pdev
, 0);
372 if (pdata
->irq
>= 0 &&
373 devm_request_irq(&pdev
->dev
, pdata
->irq
, mxc_rtc_interrupt
,
374 IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
375 dev_warn(&pdev
->dev
, "interrupt not available.\n");
379 if (pdata
->irq
>= 0) {
380 device_init_wakeup(&pdev
->dev
, 1);
381 ret
= dev_pm_set_wake_irq(&pdev
->dev
, pdata
->irq
);
383 dev_err(&pdev
->dev
, "failed to enable irq wake\n");
386 ret
= devm_rtc_register_device(rtc
);
391 static struct platform_driver mxc_rtc_driver
= {
394 .of_match_table
= imx_rtc_dt_ids
,
396 .probe
= mxc_rtc_probe
,
399 module_platform_driver(mxc_rtc_driver
)
401 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
402 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
403 MODULE_LICENSE("GPL");