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/clk.h>
13 #include <linux/of_device.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 platform_device_id imx_rtc_devtype
[] = {
75 .driver_data
= IMX1_RTC
,
78 .driver_data
= IMX21_RTC
,
83 MODULE_DEVICE_TABLE(platform
, imx_rtc_devtype
);
86 static const struct of_device_id imx_rtc_dt_ids
[] = {
87 { .compatible
= "fsl,imx1-rtc", .data
= (const void *)IMX1_RTC
},
88 { .compatible
= "fsl,imx21-rtc", .data
= (const void *)IMX21_RTC
},
91 MODULE_DEVICE_TABLE(of
, imx_rtc_dt_ids
);
94 static inline int is_imx1_rtc(struct rtc_plat_data
*data
)
96 return data
->devtype
== IMX1_RTC
;
100 * This function is used to obtain the RTC time or the alarm value in
103 static time64_t
get_alarm_or_time(struct device
*dev
, int time_alarm
)
105 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
106 void __iomem
*ioaddr
= pdata
->ioaddr
;
107 u32 day
= 0, hr
= 0, min
= 0, sec
= 0, hr_min
= 0;
109 switch (time_alarm
) {
111 day
= readw(ioaddr
+ RTC_DAYR
);
112 hr_min
= readw(ioaddr
+ RTC_HOURMIN
);
113 sec
= readw(ioaddr
+ RTC_SECOND
);
116 day
= readw(ioaddr
+ RTC_DAYALARM
);
117 hr_min
= readw(ioaddr
+ RTC_ALRM_HM
) & 0xffff;
118 sec
= readw(ioaddr
+ RTC_ALRM_SEC
);
125 return ((((time64_t
)day
* 24 + hr
) * 60) + min
) * 60 + sec
;
129 * This function sets the RTC alarm value or the time value.
131 static void set_alarm_or_time(struct device
*dev
, int time_alarm
, time64_t time
)
133 u32 tod
, day
, hr
, min
, sec
, temp
;
134 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
135 void __iomem
*ioaddr
= pdata
->ioaddr
;
137 day
= div_s64_rem(time
, 86400, &tod
);
139 /* time is within a day now */
143 /* time is within an hour now */
145 sec
= tod
- min
* 60;
147 temp
= (hr
<< 8) + min
;
149 switch (time_alarm
) {
151 writew(day
, ioaddr
+ RTC_DAYR
);
152 writew(sec
, ioaddr
+ RTC_SECOND
);
153 writew(temp
, ioaddr
+ RTC_HOURMIN
);
156 writew(day
, ioaddr
+ RTC_DAYALARM
);
157 writew(sec
, ioaddr
+ RTC_ALRM_SEC
);
158 writew(temp
, ioaddr
+ RTC_ALRM_HM
);
164 * This function updates the RTC alarm registers and then clears all the
165 * interrupt status bits.
167 static void rtc_update_alarm(struct device
*dev
, struct rtc_time
*alrm
)
170 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
171 void __iomem
*ioaddr
= pdata
->ioaddr
;
173 time
= rtc_tm_to_time64(alrm
);
175 /* clear all the interrupt status bits */
176 writew(readw(ioaddr
+ RTC_RTCISR
), ioaddr
+ RTC_RTCISR
);
177 set_alarm_or_time(dev
, MXC_RTC_ALARM
, time
);
180 static void mxc_rtc_irq_enable(struct device
*dev
, unsigned int bit
,
181 unsigned int enabled
)
183 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
184 void __iomem
*ioaddr
= pdata
->ioaddr
;
187 spin_lock_irq(&pdata
->rtc
->irq_lock
);
188 reg
= readw(ioaddr
+ RTC_RTCIENR
);
195 writew(reg
, ioaddr
+ RTC_RTCIENR
);
196 spin_unlock_irq(&pdata
->rtc
->irq_lock
);
199 /* This function is the RTC interrupt service routine. */
200 static irqreturn_t
mxc_rtc_interrupt(int irq
, void *dev_id
)
202 struct platform_device
*pdev
= dev_id
;
203 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
204 void __iomem
*ioaddr
= pdata
->ioaddr
;
209 spin_lock_irqsave(&pdata
->rtc
->irq_lock
, flags
);
210 status
= readw(ioaddr
+ RTC_RTCISR
) & readw(ioaddr
+ RTC_RTCIENR
);
211 /* clear interrupt sources */
212 writew(status
, ioaddr
+ RTC_RTCISR
);
214 /* update irq data & counter */
215 if (status
& RTC_ALM_BIT
) {
216 events
|= (RTC_AF
| RTC_IRQF
);
217 /* RTC alarm should be one-shot */
218 mxc_rtc_irq_enable(&pdev
->dev
, RTC_ALM_BIT
, 0);
221 if (status
& PIT_ALL_ON
)
222 events
|= (RTC_PF
| RTC_IRQF
);
224 rtc_update_irq(pdata
->rtc
, 1, events
);
225 spin_unlock_irqrestore(&pdata
->rtc
->irq_lock
, flags
);
230 static int mxc_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
232 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, enabled
);
237 * This function reads the current RTC time into tm in Gregorian date.
239 static int mxc_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
243 /* Avoid roll-over from reading the different registers */
245 val
= get_alarm_or_time(dev
, MXC_RTC_TIME
);
246 } while (val
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
248 rtc_time64_to_tm(val
, tm
);
254 * This function sets the internal RTC time based on tm in Gregorian date.
256 static int mxc_rtc_set_mmss(struct device
*dev
, time64_t time
)
258 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
261 * TTC_DAYR register is 9-bit in MX1 SoC, save time and day of year only
263 if (is_imx1_rtc(pdata
)) {
266 rtc_time64_to_tm(time
, &tm
);
268 time
= rtc_tm_to_time64(&tm
);
271 /* Avoid roll-over from reading the different registers */
273 set_alarm_or_time(dev
, MXC_RTC_TIME
, time
);
274 } while (time
!= get_alarm_or_time(dev
, MXC_RTC_TIME
));
280 * This function reads the current alarm value into the passed in 'alrm'
281 * argument. It updates the alrm's pending field value based on the whether
282 * an alarm interrupt occurs or not.
284 static int mxc_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
286 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
287 void __iomem
*ioaddr
= pdata
->ioaddr
;
289 rtc_time64_to_tm(get_alarm_or_time(dev
, MXC_RTC_ALARM
), &alrm
->time
);
290 alrm
->pending
= ((readw(ioaddr
+ RTC_RTCISR
) & RTC_ALM_BIT
)) ? 1 : 0;
296 * This function sets the RTC alarm based on passed in alrm.
298 static int mxc_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
300 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
302 rtc_update_alarm(dev
, &alrm
->time
);
304 memcpy(&pdata
->g_rtc_alarm
, &alrm
->time
, sizeof(struct rtc_time
));
305 mxc_rtc_irq_enable(dev
, RTC_ALM_BIT
, alrm
->enabled
);
311 static const struct rtc_class_ops mxc_rtc_ops
= {
312 .read_time
= mxc_rtc_read_time
,
313 .set_mmss64
= mxc_rtc_set_mmss
,
314 .read_alarm
= mxc_rtc_read_alarm
,
315 .set_alarm
= mxc_rtc_set_alarm
,
316 .alarm_irq_enable
= mxc_rtc_alarm_irq_enable
,
319 static int mxc_rtc_probe(struct platform_device
*pdev
)
321 struct resource
*res
;
322 struct rtc_device
*rtc
;
323 struct rtc_plat_data
*pdata
= NULL
;
327 const struct of_device_id
*of_id
;
329 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
333 of_id
= of_match_device(imx_rtc_dt_ids
, &pdev
->dev
);
335 pdata
->devtype
= (enum imx_rtc_type
)of_id
->data
;
337 pdata
->devtype
= pdev
->id_entry
->driver_data
;
339 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
340 pdata
->ioaddr
= devm_ioremap_resource(&pdev
->dev
, res
);
341 if (IS_ERR(pdata
->ioaddr
))
342 return PTR_ERR(pdata
->ioaddr
);
344 pdata
->clk_ipg
= devm_clk_get(&pdev
->dev
, "ipg");
345 if (IS_ERR(pdata
->clk_ipg
)) {
346 dev_err(&pdev
->dev
, "unable to get ipg clock!\n");
347 return PTR_ERR(pdata
->clk_ipg
);
350 ret
= clk_prepare_enable(pdata
->clk_ipg
);
354 pdata
->clk_ref
= devm_clk_get(&pdev
->dev
, "ref");
355 if (IS_ERR(pdata
->clk_ref
)) {
356 dev_err(&pdev
->dev
, "unable to get ref clock!\n");
357 ret
= PTR_ERR(pdata
->clk_ref
);
358 goto exit_put_clk_ipg
;
361 ret
= clk_prepare_enable(pdata
->clk_ref
);
363 goto exit_put_clk_ipg
;
365 rate
= clk_get_rate(pdata
->clk_ref
);
368 reg
= RTC_INPUT_CLK_32768HZ
;
369 else if (rate
== 32000)
370 reg
= RTC_INPUT_CLK_32000HZ
;
371 else if (rate
== 38400)
372 reg
= RTC_INPUT_CLK_38400HZ
;
374 dev_err(&pdev
->dev
, "rtc clock is not valid (%lu)\n", rate
);
376 goto exit_put_clk_ref
;
379 reg
|= RTC_ENABLE_BIT
;
380 writew(reg
, (pdata
->ioaddr
+ RTC_RTCCTL
));
381 if (((readw(pdata
->ioaddr
+ RTC_RTCCTL
)) & RTC_ENABLE_BIT
) == 0) {
382 dev_err(&pdev
->dev
, "hardware module can't be enabled!\n");
384 goto exit_put_clk_ref
;
387 platform_set_drvdata(pdev
, pdata
);
389 /* Configure and enable the RTC */
390 pdata
->irq
= platform_get_irq(pdev
, 0);
392 if (pdata
->irq
>= 0 &&
393 devm_request_irq(&pdev
->dev
, pdata
->irq
, mxc_rtc_interrupt
,
394 IRQF_SHARED
, pdev
->name
, pdev
) < 0) {
395 dev_warn(&pdev
->dev
, "interrupt not available.\n");
400 device_init_wakeup(&pdev
->dev
, 1);
402 rtc
= devm_rtc_device_register(&pdev
->dev
, pdev
->name
, &mxc_rtc_ops
,
406 goto exit_put_clk_ref
;
414 clk_disable_unprepare(pdata
->clk_ref
);
416 clk_disable_unprepare(pdata
->clk_ipg
);
421 static int mxc_rtc_remove(struct platform_device
*pdev
)
423 struct rtc_plat_data
*pdata
= platform_get_drvdata(pdev
);
425 clk_disable_unprepare(pdata
->clk_ref
);
426 clk_disable_unprepare(pdata
->clk_ipg
);
431 #ifdef CONFIG_PM_SLEEP
432 static int mxc_rtc_suspend(struct device
*dev
)
434 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
436 if (device_may_wakeup(dev
))
437 enable_irq_wake(pdata
->irq
);
442 static int mxc_rtc_resume(struct device
*dev
)
444 struct rtc_plat_data
*pdata
= dev_get_drvdata(dev
);
446 if (device_may_wakeup(dev
))
447 disable_irq_wake(pdata
->irq
);
453 static SIMPLE_DEV_PM_OPS(mxc_rtc_pm_ops
, mxc_rtc_suspend
, mxc_rtc_resume
);
455 static struct platform_driver mxc_rtc_driver
= {
458 .of_match_table
= of_match_ptr(imx_rtc_dt_ids
),
459 .pm
= &mxc_rtc_pm_ops
,
461 .id_table
= imx_rtc_devtype
,
462 .probe
= mxc_rtc_probe
,
463 .remove
= mxc_rtc_remove
,
466 module_platform_driver(mxc_rtc_driver
)
468 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
469 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
470 MODULE_LICENSE("GPL");