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
18#include "rtc-sa1100.h"
19
20#define RTC_DEF_DIVIDER		(32768 - 1)
21#define RTC_DEF_TRIM		0
22#define MAXFREQ_PERIODIC	1000
23
24/*
25 * PXA Registers and bits definitions
26 */
27#define RTSR_PICE	(1 << 15)	/* Periodic interrupt count enable */
28#define RTSR_PIALE	(1 << 14)	/* Periodic interrupt Alarm enable */
29#define RTSR_PIAL	(1 << 13)	/* Periodic interrupt detected */
30#define RTSR_SWALE2	(1 << 11)	/* RTC stopwatch alarm2 enable */
31#define RTSR_SWAL2	(1 << 10)	/* RTC stopwatch alarm2 detected */
32#define RTSR_SWALE1	(1 << 9)	/* RTC stopwatch alarm1 enable */
33#define RTSR_SWAL1	(1 << 8)	/* RTC stopwatch alarm1 detected */
34#define RTSR_RDALE2	(1 << 7)	/* RTC alarm2 enable */
35#define RTSR_RDAL2	(1 << 6)	/* RTC alarm2 detected */
36#define RTSR_RDALE1	(1 << 5)	/* RTC alarm1 enable */
37#define RTSR_RDAL1	(1 << 4)	/* RTC alarm1 detected */
38#define RTSR_HZE	(1 << 3)	/* HZ interrupt enable */
39#define RTSR_ALE	(1 << 2)	/* RTC alarm interrupt enable */
40#define RTSR_HZ		(1 << 1)	/* HZ rising-edge detected */
41#define RTSR_AL		(1 << 0)	/* RTC alarm detected */
42#define RTSR_TRIG_MASK	(RTSR_AL | RTSR_HZ | RTSR_RDAL1 | RTSR_RDAL2\
43			 | RTSR_SWAL1 | RTSR_SWAL2)
44#define RYxR_YEAR_S	9
45#define RYxR_YEAR_MASK	(0xfff << RYxR_YEAR_S)
46#define RYxR_MONTH_S	5
47#define RYxR_MONTH_MASK	(0xf << RYxR_MONTH_S)
48#define RYxR_DAY_MASK	0x1f
49#define RDxR_WOM_S     20
50#define RDxR_WOM_MASK  (0x7 << RDxR_WOM_S)
51#define RDxR_DOW_S     17
52#define RDxR_DOW_MASK  (0x7 << RDxR_DOW_S)
53#define RDxR_HOUR_S	12
54#define RDxR_HOUR_MASK	(0x1f << RDxR_HOUR_S)
55#define RDxR_MIN_S	6
56#define RDxR_MIN_MASK	(0x3f << RDxR_MIN_S)
57#define RDxR_SEC_MASK	0x3f
58
59#define RTSR		0x08
60#define RTTR		0x0c
61#define RDCR		0x10
62#define RYCR		0x14
63#define RDAR1		0x18
64#define RYAR1		0x1c
65#define RTCPICR		0x34
66#define PIAR		0x38
67
68#define rtc_readl(pxa_rtc, reg)	\
69	__raw_readl((pxa_rtc)->base + (reg))
70#define rtc_writel(pxa_rtc, reg, value)	\
71	__raw_writel((value), (pxa_rtc)->base + (reg))
72
73struct pxa_rtc {
74	struct sa1100_rtc sa1100_rtc;
75	struct resource	*ress;
76	void __iomem		*base;
77	struct rtc_device	*rtc;
78	spinlock_t		lock;		/* Protects this structure */
79};
80
81
82static u32 ryxr_calc(struct rtc_time *tm)
83{
84	return ((tm->tm_year + 1900) << RYxR_YEAR_S)
85		| ((tm->tm_mon + 1) << RYxR_MONTH_S)
86		| tm->tm_mday;
87}
88
89static u32 rdxr_calc(struct rtc_time *tm)
90{
91	return ((((tm->tm_mday + 6) / 7) << RDxR_WOM_S) & RDxR_WOM_MASK)
92		| (((tm->tm_wday + 1) << RDxR_DOW_S) & RDxR_DOW_MASK)
93		| (tm->tm_hour << RDxR_HOUR_S)
94		| (tm->tm_min << RDxR_MIN_S)
95		| tm->tm_sec;
96}
97
98static void tm_calc(u32 rycr, u32 rdcr, struct rtc_time *tm)
99{
100	tm->tm_year = ((rycr & RYxR_YEAR_MASK) >> RYxR_YEAR_S) - 1900;
101	tm->tm_mon = (((rycr & RYxR_MONTH_MASK) >> RYxR_MONTH_S)) - 1;
102	tm->tm_mday = (rycr & RYxR_DAY_MASK);
103	tm->tm_wday = ((rycr & RDxR_DOW_MASK) >> RDxR_DOW_S) - 1;
104	tm->tm_hour = (rdcr & RDxR_HOUR_MASK) >> RDxR_HOUR_S;
105	tm->tm_min = (rdcr & RDxR_MIN_MASK) >> RDxR_MIN_S;
106	tm->tm_sec = rdcr & RDxR_SEC_MASK;
107}
108
109static void rtsr_clear_bits(struct pxa_rtc *pxa_rtc, u32 mask)
110{
111	u32 rtsr;
112
113	rtsr = rtc_readl(pxa_rtc, RTSR);
114	rtsr &= ~RTSR_TRIG_MASK;
115	rtsr &= ~mask;
116	rtc_writel(pxa_rtc, RTSR, rtsr);
117}
118
119static void rtsr_set_bits(struct pxa_rtc *pxa_rtc, u32 mask)
120{
121	u32 rtsr;
122
123	rtsr = rtc_readl(pxa_rtc, RTSR);
124	rtsr &= ~RTSR_TRIG_MASK;
125	rtsr |= mask;
126	rtc_writel(pxa_rtc, RTSR, rtsr);
127}
128
129static irqreturn_t pxa_rtc_irq(int irq, void *dev_id)
130{
131	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev_id);
132	u32 rtsr;
133	unsigned long events = 0;
134
135	spin_lock(&pxa_rtc->lock);
136
137	/* clear interrupt sources */
138	rtsr = rtc_readl(pxa_rtc, RTSR);
139	rtc_writel(pxa_rtc, RTSR, rtsr);
140
141	/* temporary disable rtc interrupts */
142	rtsr_clear_bits(pxa_rtc, RTSR_RDALE1 | RTSR_PIALE | RTSR_HZE);
143
144	/* clear alarm interrupt if it has occurred */
145	if (rtsr & RTSR_RDAL1)
146		rtsr &= ~RTSR_RDALE1;
147
148	/* update irq data & counter */
149	if (rtsr & RTSR_RDAL1)
150		events |= RTC_AF | RTC_IRQF;
151	if (rtsr & RTSR_HZ)
152		events |= RTC_UF | RTC_IRQF;
153	if (rtsr & RTSR_PIAL)
154		events |= RTC_PF | RTC_IRQF;
155
156	rtc_update_irq(pxa_rtc->rtc, 1, events);
157
158	/* enable back rtc interrupts */
159	rtc_writel(pxa_rtc, RTSR, rtsr & ~RTSR_TRIG_MASK);
160
161	spin_unlock(&pxa_rtc->lock);
162	return IRQ_HANDLED;
163}
164
165static int pxa_rtc_open(struct device *dev)
166{
167	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
168	int ret;
169
170	ret = request_irq(pxa_rtc->sa1100_rtc.irq_1hz, pxa_rtc_irq, 0,
171			  "rtc 1Hz", dev);
172	if (ret < 0) {
173		dev_err(dev, "can't get irq %i, err %d\n",
174			pxa_rtc->sa1100_rtc.irq_1hz, ret);
175		goto err_irq_1Hz;
176	}
177	ret = request_irq(pxa_rtc->sa1100_rtc.irq_alarm, pxa_rtc_irq, 0,
178			  "rtc Alrm", dev);
179	if (ret < 0) {
180		dev_err(dev, "can't get irq %i, err %d\n",
181			pxa_rtc->sa1100_rtc.irq_alarm, ret);
182		goto err_irq_Alrm;
183	}
184
185	return 0;
186
187err_irq_Alrm:
188	free_irq(pxa_rtc->sa1100_rtc.irq_1hz, dev);
189err_irq_1Hz:
190	return ret;
191}
192
193static void pxa_rtc_release(struct device *dev)
194{
195	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
196
197	spin_lock_irq(&pxa_rtc->lock);
198	rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
199	spin_unlock_irq(&pxa_rtc->lock);
200
201	free_irq(pxa_rtc->sa1100_rtc.irq_1hz, dev);
202	free_irq(pxa_rtc->sa1100_rtc.irq_alarm, dev);
203}
204
205static int pxa_alarm_irq_enable(struct device *dev, unsigned int enabled)
206{
207	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
208
209	spin_lock_irq(&pxa_rtc->lock);
210
211	if (enabled)
212		rtsr_set_bits(pxa_rtc, RTSR_RDALE1);
213	else
214		rtsr_clear_bits(pxa_rtc, RTSR_RDALE1);
215
216	spin_unlock_irq(&pxa_rtc->lock);
217	return 0;
218}
219
220static int pxa_rtc_read_time(struct device *dev, struct rtc_time *tm)
221{
222	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
223	u32 rycr, rdcr;
224
225	rycr = rtc_readl(pxa_rtc, RYCR);
226	rdcr = rtc_readl(pxa_rtc, RDCR);
227
228	tm_calc(rycr, rdcr, tm);
229	return 0;
230}
231
232static int pxa_rtc_set_time(struct device *dev, struct rtc_time *tm)
233{
234	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
235
236	rtc_writel(pxa_rtc, RYCR, ryxr_calc(tm));
237	rtc_writel(pxa_rtc, RDCR, rdxr_calc(tm));
238
239	return 0;
240}
241
242static int pxa_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
243{
244	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
245	u32 rtsr, ryar, rdar;
246
247	ryar = rtc_readl(pxa_rtc, RYAR1);
248	rdar = rtc_readl(pxa_rtc, RDAR1);
249	tm_calc(ryar, rdar, &alrm->time);
250
251	rtsr = rtc_readl(pxa_rtc, RTSR);
252	alrm->enabled = (rtsr & RTSR_RDALE1) ? 1 : 0;
253	alrm->pending = (rtsr & RTSR_RDAL1) ? 1 : 0;
254	return 0;
255}
256
257static int pxa_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
258{
259	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
260	u32 rtsr;
261
262	spin_lock_irq(&pxa_rtc->lock);
263
264	rtc_writel(pxa_rtc, RYAR1, ryxr_calc(&alrm->time));
265	rtc_writel(pxa_rtc, RDAR1, rdxr_calc(&alrm->time));
266
267	rtsr = rtc_readl(pxa_rtc, RTSR);
268	if (alrm->enabled)
269		rtsr |= RTSR_RDALE1;
270	else
271		rtsr &= ~RTSR_RDALE1;
272	rtc_writel(pxa_rtc, RTSR, rtsr);
273
274	spin_unlock_irq(&pxa_rtc->lock);
275
276	return 0;
277}
278
279static int pxa_rtc_proc(struct device *dev, struct seq_file *seq)
280{
281	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
282
283	seq_printf(seq, "trim/divider\t: 0x%08x\n", rtc_readl(pxa_rtc, RTTR));
284	seq_printf(seq, "update_IRQ\t: %s\n",
285		   (rtc_readl(pxa_rtc, RTSR) & RTSR_HZE) ? "yes" : "no");
286	seq_printf(seq, "periodic_IRQ\t: %s\n",
287		   (rtc_readl(pxa_rtc, RTSR) & RTSR_PIALE) ? "yes" : "no");
288	seq_printf(seq, "periodic_freq\t: %u\n", rtc_readl(pxa_rtc, PIAR));
289
290	return 0;
291}
292
293static const struct rtc_class_ops pxa_rtc_ops = {
294	.read_time = pxa_rtc_read_time,
295	.set_time = pxa_rtc_set_time,
296	.read_alarm = pxa_rtc_read_alarm,
297	.set_alarm = pxa_rtc_set_alarm,
298	.alarm_irq_enable = pxa_alarm_irq_enable,
299	.proc = pxa_rtc_proc,
300};
301
302static int __init pxa_rtc_probe(struct platform_device *pdev)
303{
304	struct device *dev = &pdev->dev;
305	struct pxa_rtc *pxa_rtc;
306	struct sa1100_rtc *sa1100_rtc;
307	int ret;
308
309	pxa_rtc = devm_kzalloc(dev, sizeof(*pxa_rtc), GFP_KERNEL);
310	if (!pxa_rtc)
311		return -ENOMEM;
312	sa1100_rtc = &pxa_rtc->sa1100_rtc;
313
314	spin_lock_init(&pxa_rtc->lock);
315	platform_set_drvdata(pdev, pxa_rtc);
316
317	pxa_rtc->ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
318	if (!pxa_rtc->ress) {
319		dev_err(dev, "No I/O memory resource defined\n");
320		return -ENXIO;
321	}
322
323	sa1100_rtc->irq_1hz = platform_get_irq(pdev, 0);
324	if (sa1100_rtc->irq_1hz < 0)
325		return -ENXIO;
326	sa1100_rtc->irq_alarm = platform_get_irq(pdev, 1);
327	if (sa1100_rtc->irq_alarm < 0)
328		return -ENXIO;
329
330	sa1100_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
331	if (IS_ERR(sa1100_rtc->rtc))
332		return PTR_ERR(sa1100_rtc->rtc);
333
334	pxa_rtc->base = devm_ioremap(dev, pxa_rtc->ress->start,
335				resource_size(pxa_rtc->ress));
336	if (!pxa_rtc->base) {
337		dev_err(dev, "Unable to map pxa RTC I/O memory\n");
338		return -ENOMEM;
339	}
340
341	pxa_rtc_open(dev);
342
343	sa1100_rtc->rcnr = pxa_rtc->base + 0x0;
344	sa1100_rtc->rtsr = pxa_rtc->base + 0x8;
345	sa1100_rtc->rtar = pxa_rtc->base + 0x4;
346	sa1100_rtc->rttr = pxa_rtc->base + 0xc;
347	ret = sa1100_rtc_init(pdev, sa1100_rtc);
348	if (ret) {
349		dev_err(dev, "Unable to init SA1100 RTC sub-device\n");
350		return ret;
351	}
352
353	rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
354
355	pxa_rtc->rtc = devm_rtc_device_register(&pdev->dev, "pxa-rtc",
356						&pxa_rtc_ops, THIS_MODULE);
357	if (IS_ERR(pxa_rtc->rtc)) {
358		ret = PTR_ERR(pxa_rtc->rtc);
359		dev_err(dev, "Failed to register RTC device -> %d\n", ret);
360		return ret;
361	}
362
363	device_init_wakeup(dev, 1);
364
365	return 0;
366}
367
368static void __exit pxa_rtc_remove(struct platform_device *pdev)
369{
370	struct device *dev = &pdev->dev;
371
372	pxa_rtc_release(dev);
373}
374
375#ifdef CONFIG_OF
376static const struct of_device_id pxa_rtc_dt_ids[] = {
377	{ .compatible = "marvell,pxa-rtc" },
378	{}
379};
380MODULE_DEVICE_TABLE(of, pxa_rtc_dt_ids);
381#endif
382
383#ifdef CONFIG_PM_SLEEP
384static int pxa_rtc_suspend(struct device *dev)
385{
386	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
387
388	if (device_may_wakeup(dev))
389		enable_irq_wake(pxa_rtc->sa1100_rtc.irq_alarm);
390	return 0;
391}
392
393static int pxa_rtc_resume(struct device *dev)
394{
395	struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
396
397	if (device_may_wakeup(dev))
398		disable_irq_wake(pxa_rtc->sa1100_rtc.irq_alarm);
399	return 0;
400}
401#endif
402
403static SIMPLE_DEV_PM_OPS(pxa_rtc_pm_ops, pxa_rtc_suspend, pxa_rtc_resume);
404
405/*
406 * pxa_rtc_remove() lives in .exit.text. For drivers registered via
407 * module_platform_driver_probe() this is ok because they cannot get unbound at
408 * runtime. So mark the driver struct with __refdata to prevent modpost
409 * triggering a section mismatch warning.
410 */
411static struct platform_driver pxa_rtc_driver __refdata = {
412	.remove_new	= __exit_p(pxa_rtc_remove),
413	.driver		= {
414		.name	= "pxa-rtc",
415		.of_match_table = of_match_ptr(pxa_rtc_dt_ids),
416		.pm	= &pxa_rtc_pm_ops,
417	},
418};
419
420module_platform_driver_probe(pxa_rtc_driver, pxa_rtc_probe);
421
422MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
423MODULE_DESCRIPTION("PXA27x/PXA3xx Realtime Clock Driver (RTC)");
424MODULE_LICENSE("GPL");
425MODULE_ALIAS("platform:pxa-rtc");
426