xref: /openbmc/linux/drivers/rtc/rtc-pxa.c (revision f71a261a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Real Time Clock interface for XScale PXA27x and PXA3xx
4  *
5  * Copyright (C) 2008 Robert Jarzmik
6  */
7 
8 #include <linux/init.h>
9 #include <linux/platform_device.h>
10 #include <linux/module.h>
11 #include <linux/rtc.h>
12 #include <linux/seq_file.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/slab.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 
19 #include "rtc-sa1100.h"
20 
21 #define RTC_DEF_DIVIDER		(32768 - 1)
22 #define RTC_DEF_TRIM		0
23 #define MAXFREQ_PERIODIC	1000
24 
25 /*
26  * PXA Registers and bits definitions
27  */
28 #define RTSR_PICE	(1 << 15)	/* Periodic interrupt count enable */
29 #define RTSR_PIALE	(1 << 14)	/* Periodic interrupt Alarm enable */
30 #define RTSR_PIAL	(1 << 13)	/* Periodic interrupt detected */
31 #define RTSR_SWALE2	(1 << 11)	/* RTC stopwatch alarm2 enable */
32 #define RTSR_SWAL2	(1 << 10)	/* RTC stopwatch alarm2 detected */
33 #define RTSR_SWALE1	(1 << 9)	/* RTC stopwatch alarm1 enable */
34 #define RTSR_SWAL1	(1 << 8)	/* RTC stopwatch alarm1 detected */
35 #define RTSR_RDALE2	(1 << 7)	/* RTC alarm2 enable */
36 #define RTSR_RDAL2	(1 << 6)	/* RTC alarm2 detected */
37 #define RTSR_RDALE1	(1 << 5)	/* RTC alarm1 enable */
38 #define RTSR_RDAL1	(1 << 4)	/* RTC alarm1 detected */
39 #define RTSR_HZE	(1 << 3)	/* HZ interrupt enable */
40 #define RTSR_ALE	(1 << 2)	/* RTC alarm interrupt enable */
41 #define RTSR_HZ		(1 << 1)	/* HZ rising-edge detected */
42 #define RTSR_AL		(1 << 0)	/* RTC alarm detected */
43 #define RTSR_TRIG_MASK	(RTSR_AL | RTSR_HZ | RTSR_RDAL1 | RTSR_RDAL2\
44 			 | RTSR_SWAL1 | RTSR_SWAL2)
45 #define RYxR_YEAR_S	9
46 #define RYxR_YEAR_MASK	(0xfff << RYxR_YEAR_S)
47 #define RYxR_MONTH_S	5
48 #define RYxR_MONTH_MASK	(0xf << RYxR_MONTH_S)
49 #define RYxR_DAY_MASK	0x1f
50 #define RDxR_WOM_S     20
51 #define RDxR_WOM_MASK  (0x7 << RDxR_WOM_S)
52 #define RDxR_DOW_S     17
53 #define RDxR_DOW_MASK  (0x7 << RDxR_DOW_S)
54 #define RDxR_HOUR_S	12
55 #define RDxR_HOUR_MASK	(0x1f << RDxR_HOUR_S)
56 #define RDxR_MIN_S	6
57 #define RDxR_MIN_MASK	(0x3f << RDxR_MIN_S)
58 #define RDxR_SEC_MASK	0x3f
59 
60 #define RTSR		0x08
61 #define RTTR		0x0c
62 #define RDCR		0x10
63 #define RYCR		0x14
64 #define RDAR1		0x18
65 #define RYAR1		0x1c
66 #define RTCPICR		0x34
67 #define PIAR		0x38
68 
69 #define rtc_readl(pxa_rtc, reg)	\
70 	__raw_readl((pxa_rtc)->base + (reg))
71 #define rtc_writel(pxa_rtc, reg, value)	\
72 	__raw_writel((value), (pxa_rtc)->base + (reg))
73 
74 struct pxa_rtc {
75 	struct sa1100_rtc sa1100_rtc;
76 	struct resource	*ress;
77 	void __iomem		*base;
78 	struct rtc_device	*rtc;
79 	spinlock_t		lock;		/* Protects this structure */
80 };
81 
82 
83 static u32 ryxr_calc(struct rtc_time *tm)
84 {
85 	return ((tm->tm_year + 1900) << RYxR_YEAR_S)
86 		| ((tm->tm_mon + 1) << RYxR_MONTH_S)
87 		| tm->tm_mday;
88 }
89 
90 static u32 rdxr_calc(struct rtc_time *tm)
91 {
92 	return ((((tm->tm_mday + 6) / 7) << RDxR_WOM_S) & RDxR_WOM_MASK)
93 		| (((tm->tm_wday + 1) << RDxR_DOW_S) & RDxR_DOW_MASK)
94 		| (tm->tm_hour << RDxR_HOUR_S)
95 		| (tm->tm_min << RDxR_MIN_S)
96 		| tm->tm_sec;
97 }
98 
99 static void tm_calc(u32 rycr, u32 rdcr, struct rtc_time *tm)
100 {
101 	tm->tm_year = ((rycr & RYxR_YEAR_MASK) >> RYxR_YEAR_S) - 1900;
102 	tm->tm_mon = (((rycr & RYxR_MONTH_MASK) >> RYxR_MONTH_S)) - 1;
103 	tm->tm_mday = (rycr & RYxR_DAY_MASK);
104 	tm->tm_wday = ((rycr & RDxR_DOW_MASK) >> RDxR_DOW_S) - 1;
105 	tm->tm_hour = (rdcr & RDxR_HOUR_MASK) >> RDxR_HOUR_S;
106 	tm->tm_min = (rdcr & RDxR_MIN_MASK) >> RDxR_MIN_S;
107 	tm->tm_sec = rdcr & RDxR_SEC_MASK;
108 }
109 
110 static void rtsr_clear_bits(struct pxa_rtc *pxa_rtc, u32 mask)
111 {
112 	u32 rtsr;
113 
114 	rtsr = rtc_readl(pxa_rtc, RTSR);
115 	rtsr &= ~RTSR_TRIG_MASK;
116 	rtsr &= ~mask;
117 	rtc_writel(pxa_rtc, RTSR, rtsr);
118 }
119 
120 static void rtsr_set_bits(struct pxa_rtc *pxa_rtc, u32 mask)
121 {
122 	u32 rtsr;
123 
124 	rtsr = rtc_readl(pxa_rtc, RTSR);
125 	rtsr &= ~RTSR_TRIG_MASK;
126 	rtsr |= mask;
127 	rtc_writel(pxa_rtc, RTSR, rtsr);
128 }
129 
130 static irqreturn_t pxa_rtc_irq(int irq, void *dev_id)
131 {
132 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev_id);
133 	u32 rtsr;
134 	unsigned long events = 0;
135 
136 	spin_lock(&pxa_rtc->lock);
137 
138 	/* clear interrupt sources */
139 	rtsr = rtc_readl(pxa_rtc, RTSR);
140 	rtc_writel(pxa_rtc, RTSR, rtsr);
141 
142 	/* temporary disable rtc interrupts */
143 	rtsr_clear_bits(pxa_rtc, RTSR_RDALE1 | RTSR_PIALE | RTSR_HZE);
144 
145 	/* clear alarm interrupt if it has occurred */
146 	if (rtsr & RTSR_RDAL1)
147 		rtsr &= ~RTSR_RDALE1;
148 
149 	/* update irq data & counter */
150 	if (rtsr & RTSR_RDAL1)
151 		events |= RTC_AF | RTC_IRQF;
152 	if (rtsr & RTSR_HZ)
153 		events |= RTC_UF | RTC_IRQF;
154 	if (rtsr & RTSR_PIAL)
155 		events |= RTC_PF | RTC_IRQF;
156 
157 	rtc_update_irq(pxa_rtc->rtc, 1, events);
158 
159 	/* enable back rtc interrupts */
160 	rtc_writel(pxa_rtc, RTSR, rtsr & ~RTSR_TRIG_MASK);
161 
162 	spin_unlock(&pxa_rtc->lock);
163 	return IRQ_HANDLED;
164 }
165 
166 static int pxa_rtc_open(struct device *dev)
167 {
168 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
169 	int ret;
170 
171 	ret = request_irq(pxa_rtc->sa1100_rtc.irq_1hz, pxa_rtc_irq, 0,
172 			  "rtc 1Hz", dev);
173 	if (ret < 0) {
174 		dev_err(dev, "can't get irq %i, err %d\n",
175 			pxa_rtc->sa1100_rtc.irq_1hz, ret);
176 		goto err_irq_1Hz;
177 	}
178 	ret = request_irq(pxa_rtc->sa1100_rtc.irq_alarm, pxa_rtc_irq, 0,
179 			  "rtc Alrm", dev);
180 	if (ret < 0) {
181 		dev_err(dev, "can't get irq %i, err %d\n",
182 			pxa_rtc->sa1100_rtc.irq_alarm, ret);
183 		goto err_irq_Alrm;
184 	}
185 
186 	return 0;
187 
188 err_irq_Alrm:
189 	free_irq(pxa_rtc->sa1100_rtc.irq_1hz, dev);
190 err_irq_1Hz:
191 	return ret;
192 }
193 
194 static void pxa_rtc_release(struct device *dev)
195 {
196 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
197 
198 	spin_lock_irq(&pxa_rtc->lock);
199 	rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
200 	spin_unlock_irq(&pxa_rtc->lock);
201 
202 	free_irq(pxa_rtc->sa1100_rtc.irq_1hz, dev);
203 	free_irq(pxa_rtc->sa1100_rtc.irq_alarm, dev);
204 }
205 
206 static int pxa_alarm_irq_enable(struct device *dev, unsigned int enabled)
207 {
208 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
209 
210 	spin_lock_irq(&pxa_rtc->lock);
211 
212 	if (enabled)
213 		rtsr_set_bits(pxa_rtc, RTSR_RDALE1);
214 	else
215 		rtsr_clear_bits(pxa_rtc, RTSR_RDALE1);
216 
217 	spin_unlock_irq(&pxa_rtc->lock);
218 	return 0;
219 }
220 
221 static int pxa_rtc_read_time(struct device *dev, struct rtc_time *tm)
222 {
223 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
224 	u32 rycr, rdcr;
225 
226 	rycr = rtc_readl(pxa_rtc, RYCR);
227 	rdcr = rtc_readl(pxa_rtc, RDCR);
228 
229 	tm_calc(rycr, rdcr, tm);
230 	return 0;
231 }
232 
233 static int pxa_rtc_set_time(struct device *dev, struct rtc_time *tm)
234 {
235 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
236 
237 	rtc_writel(pxa_rtc, RYCR, ryxr_calc(tm));
238 	rtc_writel(pxa_rtc, RDCR, rdxr_calc(tm));
239 
240 	return 0;
241 }
242 
243 static int pxa_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
244 {
245 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
246 	u32 rtsr, ryar, rdar;
247 
248 	ryar = rtc_readl(pxa_rtc, RYAR1);
249 	rdar = rtc_readl(pxa_rtc, RDAR1);
250 	tm_calc(ryar, rdar, &alrm->time);
251 
252 	rtsr = rtc_readl(pxa_rtc, RTSR);
253 	alrm->enabled = (rtsr & RTSR_RDALE1) ? 1 : 0;
254 	alrm->pending = (rtsr & RTSR_RDAL1) ? 1 : 0;
255 	return 0;
256 }
257 
258 static int pxa_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
259 {
260 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
261 	u32 rtsr;
262 
263 	spin_lock_irq(&pxa_rtc->lock);
264 
265 	rtc_writel(pxa_rtc, RYAR1, ryxr_calc(&alrm->time));
266 	rtc_writel(pxa_rtc, RDAR1, rdxr_calc(&alrm->time));
267 
268 	rtsr = rtc_readl(pxa_rtc, RTSR);
269 	if (alrm->enabled)
270 		rtsr |= RTSR_RDALE1;
271 	else
272 		rtsr &= ~RTSR_RDALE1;
273 	rtc_writel(pxa_rtc, RTSR, rtsr);
274 
275 	spin_unlock_irq(&pxa_rtc->lock);
276 
277 	return 0;
278 }
279 
280 static int pxa_rtc_proc(struct device *dev, struct seq_file *seq)
281 {
282 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
283 
284 	seq_printf(seq, "trim/divider\t: 0x%08x\n", rtc_readl(pxa_rtc, RTTR));
285 	seq_printf(seq, "update_IRQ\t: %s\n",
286 		   (rtc_readl(pxa_rtc, RTSR) & RTSR_HZE) ? "yes" : "no");
287 	seq_printf(seq, "periodic_IRQ\t: %s\n",
288 		   (rtc_readl(pxa_rtc, RTSR) & RTSR_PIALE) ? "yes" : "no");
289 	seq_printf(seq, "periodic_freq\t: %u\n", rtc_readl(pxa_rtc, PIAR));
290 
291 	return 0;
292 }
293 
294 static const struct rtc_class_ops pxa_rtc_ops = {
295 	.read_time = pxa_rtc_read_time,
296 	.set_time = pxa_rtc_set_time,
297 	.read_alarm = pxa_rtc_read_alarm,
298 	.set_alarm = pxa_rtc_set_alarm,
299 	.alarm_irq_enable = pxa_alarm_irq_enable,
300 	.proc = pxa_rtc_proc,
301 };
302 
303 static int __init pxa_rtc_probe(struct platform_device *pdev)
304 {
305 	struct device *dev = &pdev->dev;
306 	struct pxa_rtc *pxa_rtc;
307 	struct sa1100_rtc *sa1100_rtc;
308 	int ret;
309 
310 	pxa_rtc = devm_kzalloc(dev, sizeof(*pxa_rtc), GFP_KERNEL);
311 	if (!pxa_rtc)
312 		return -ENOMEM;
313 	sa1100_rtc = &pxa_rtc->sa1100_rtc;
314 
315 	spin_lock_init(&pxa_rtc->lock);
316 	platform_set_drvdata(pdev, pxa_rtc);
317 
318 	pxa_rtc->ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
319 	if (!pxa_rtc->ress) {
320 		dev_err(dev, "No I/O memory resource defined\n");
321 		return -ENXIO;
322 	}
323 
324 	sa1100_rtc->irq_1hz = platform_get_irq(pdev, 0);
325 	if (sa1100_rtc->irq_1hz < 0)
326 		return -ENXIO;
327 	sa1100_rtc->irq_alarm = platform_get_irq(pdev, 1);
328 	if (sa1100_rtc->irq_alarm < 0)
329 		return -ENXIO;
330 
331 	sa1100_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
332 	if (IS_ERR(sa1100_rtc->rtc))
333 		return PTR_ERR(sa1100_rtc->rtc);
334 
335 	pxa_rtc->base = devm_ioremap(dev, pxa_rtc->ress->start,
336 				resource_size(pxa_rtc->ress));
337 	if (!pxa_rtc->base) {
338 		dev_err(dev, "Unable to map pxa RTC I/O memory\n");
339 		return -ENOMEM;
340 	}
341 
342 	pxa_rtc_open(dev);
343 
344 	sa1100_rtc->rcnr = pxa_rtc->base + 0x0;
345 	sa1100_rtc->rtsr = pxa_rtc->base + 0x8;
346 	sa1100_rtc->rtar = pxa_rtc->base + 0x4;
347 	sa1100_rtc->rttr = pxa_rtc->base + 0xc;
348 	ret = sa1100_rtc_init(pdev, sa1100_rtc);
349 	if (ret) {
350 		dev_err(dev, "Unable to init SA1100 RTC sub-device\n");
351 		return ret;
352 	}
353 
354 	rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
355 
356 	pxa_rtc->rtc = devm_rtc_device_register(&pdev->dev, "pxa-rtc",
357 						&pxa_rtc_ops, THIS_MODULE);
358 	if (IS_ERR(pxa_rtc->rtc)) {
359 		ret = PTR_ERR(pxa_rtc->rtc);
360 		dev_err(dev, "Failed to register RTC device -> %d\n", ret);
361 		return ret;
362 	}
363 
364 	device_init_wakeup(dev, 1);
365 
366 	return 0;
367 }
368 
369 static int __exit pxa_rtc_remove(struct platform_device *pdev)
370 {
371 	struct device *dev = &pdev->dev;
372 
373 	pxa_rtc_release(dev);
374 	return 0;
375 }
376 
377 #ifdef CONFIG_OF
378 static const struct of_device_id pxa_rtc_dt_ids[] = {
379 	{ .compatible = "marvell,pxa-rtc" },
380 	{}
381 };
382 MODULE_DEVICE_TABLE(of, pxa_rtc_dt_ids);
383 #endif
384 
385 #ifdef CONFIG_PM_SLEEP
386 static int pxa_rtc_suspend(struct device *dev)
387 {
388 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
389 
390 	if (device_may_wakeup(dev))
391 		enable_irq_wake(pxa_rtc->sa1100_rtc.irq_alarm);
392 	return 0;
393 }
394 
395 static int pxa_rtc_resume(struct device *dev)
396 {
397 	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
398 
399 	if (device_may_wakeup(dev))
400 		disable_irq_wake(pxa_rtc->sa1100_rtc.irq_alarm);
401 	return 0;
402 }
403 #endif
404 
405 static SIMPLE_DEV_PM_OPS(pxa_rtc_pm_ops, pxa_rtc_suspend, pxa_rtc_resume);
406 
407 static struct platform_driver pxa_rtc_driver = {
408 	.remove		= __exit_p(pxa_rtc_remove),
409 	.driver		= {
410 		.name	= "pxa-rtc",
411 		.of_match_table = of_match_ptr(pxa_rtc_dt_ids),
412 		.pm	= &pxa_rtc_pm_ops,
413 	},
414 };
415 
416 module_platform_driver_probe(pxa_rtc_driver, pxa_rtc_probe);
417 
418 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
419 MODULE_DESCRIPTION("PXA27x/PXA3xx Realtime Clock Driver (RTC)");
420 MODULE_LICENSE("GPL");
421 MODULE_ALIAS("platform:pxa-rtc");
422