1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for the RTC in Marvell SoCs.
4 */
5
6#include <linux/init.h>
7#include <linux/kernel.h>
8#include <linux/rtc.h>
9#include <linux/bcd.h>
10#include <linux/bitops.h>
11#include <linux/io.h>
12#include <linux/platform_device.h>
13#include <linux/of.h>
14#include <linux/delay.h>
15#include <linux/clk.h>
16#include <linux/gfp.h>
17#include <linux/module.h>
18
19
20#define RTC_TIME_REG_OFFS	0
21#define RTC_SECONDS_OFFS	0
22#define RTC_MINUTES_OFFS	8
23#define RTC_HOURS_OFFS		16
24#define RTC_WDAY_OFFS		24
25#define RTC_HOURS_12H_MODE	BIT(22) /* 12 hour mode */
26
27#define RTC_DATE_REG_OFFS	4
28#define RTC_MDAY_OFFS		0
29#define RTC_MONTH_OFFS		8
30#define RTC_YEAR_OFFS		16
31
32#define RTC_ALARM_TIME_REG_OFFS	8
33#define RTC_ALARM_DATE_REG_OFFS	0xc
34#define RTC_ALARM_VALID		BIT(7)
35
36#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS	0x10
37#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS	0x14
38
39struct rtc_plat_data {
40	struct rtc_device *rtc;
41	void __iomem *ioaddr;
42	int		irq;
43	struct clk	*clk;
44};
45
46static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
47{
48	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
49	void __iomem *ioaddr = pdata->ioaddr;
50	u32	rtc_reg;
51
52	rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
53		(bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
54		(bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
55		(bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
56	writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
57
58	rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
59		(bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
60		(bin2bcd(tm->tm_year - 100) << RTC_YEAR_OFFS);
61	writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
62
63	return 0;
64}
65
66static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
67{
68	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
69	void __iomem *ioaddr = pdata->ioaddr;
70	u32	rtc_time, rtc_date;
71	unsigned int year, month, day, hour, minute, second, wday;
72
73	rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
74	rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
75
76	second = rtc_time & 0x7f;
77	minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
78	hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
79	wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
80
81	day = rtc_date & 0x3f;
82	month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
83	year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
84
85	tm->tm_sec = bcd2bin(second);
86	tm->tm_min = bcd2bin(minute);
87	tm->tm_hour = bcd2bin(hour);
88	tm->tm_mday = bcd2bin(day);
89	tm->tm_wday = bcd2bin(wday);
90	tm->tm_mon = bcd2bin(month) - 1;
91	/* hw counts from year 2000, but tm_year is relative to 1900 */
92	tm->tm_year = bcd2bin(year) + 100;
93
94	return 0;
95}
96
97static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
98{
99	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
100	void __iomem *ioaddr = pdata->ioaddr;
101	u32	rtc_time, rtc_date;
102	unsigned int year, month, day, hour, minute, second, wday;
103
104	rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
105	rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
106
107	second = rtc_time & 0x7f;
108	minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
109	hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
110	wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
111
112	day = rtc_date & 0x3f;
113	month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
114	year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
115
116	alm->time.tm_sec = bcd2bin(second);
117	alm->time.tm_min = bcd2bin(minute);
118	alm->time.tm_hour = bcd2bin(hour);
119	alm->time.tm_mday = bcd2bin(day);
120	alm->time.tm_wday = bcd2bin(wday);
121	alm->time.tm_mon = bcd2bin(month) - 1;
122	/* hw counts from year 2000, but tm_year is relative to 1900 */
123	alm->time.tm_year = bcd2bin(year) + 100;
124
125	alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
126
127	return rtc_valid_tm(&alm->time);
128}
129
130static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
131{
132	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
133	void __iomem *ioaddr = pdata->ioaddr;
134	u32 rtc_reg = 0;
135
136	if (alm->time.tm_sec >= 0)
137		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
138			<< RTC_SECONDS_OFFS;
139	if (alm->time.tm_min >= 0)
140		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
141			<< RTC_MINUTES_OFFS;
142	if (alm->time.tm_hour >= 0)
143		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
144			<< RTC_HOURS_OFFS;
145
146	writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
147
148	if (alm->time.tm_mday >= 0)
149		rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
150			<< RTC_MDAY_OFFS;
151	else
152		rtc_reg = 0;
153
154	if (alm->time.tm_mon >= 0)
155		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
156			<< RTC_MONTH_OFFS;
157
158	if (alm->time.tm_year >= 0)
159		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year - 100))
160			<< RTC_YEAR_OFFS;
161
162	writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
163	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
164	writel(alm->enabled ? 1 : 0,
165	       ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
166
167	return 0;
168}
169
170static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
171{
172	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
173	void __iomem *ioaddr = pdata->ioaddr;
174
175	if (pdata->irq < 0)
176		return -EINVAL; /* fall back into rtc-dev's emulation */
177
178	if (enabled)
179		writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
180	else
181		writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
182	return 0;
183}
184
185static irqreturn_t mv_rtc_interrupt(int irq, void *data)
186{
187	struct rtc_plat_data *pdata = data;
188	void __iomem *ioaddr = pdata->ioaddr;
189
190	/* alarm irq? */
191	if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
192		return IRQ_NONE;
193
194	/* clear interrupt */
195	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
196	rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
197	return IRQ_HANDLED;
198}
199
200static const struct rtc_class_ops mv_rtc_ops = {
201	.read_time	= mv_rtc_read_time,
202	.set_time	= mv_rtc_set_time,
203	.read_alarm	= mv_rtc_read_alarm,
204	.set_alarm	= mv_rtc_set_alarm,
205	.alarm_irq_enable = mv_rtc_alarm_irq_enable,
206};
207
208static int __init mv_rtc_probe(struct platform_device *pdev)
209{
210	struct rtc_plat_data *pdata;
211	u32 rtc_time;
212	int ret = 0;
213
214	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
215	if (!pdata)
216		return -ENOMEM;
217
218	pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
219	if (IS_ERR(pdata->ioaddr))
220		return PTR_ERR(pdata->ioaddr);
221
222	pdata->clk = devm_clk_get(&pdev->dev, NULL);
223	/* Not all SoCs require a clock.*/
224	if (!IS_ERR(pdata->clk))
225		clk_prepare_enable(pdata->clk);
226
227	/* make sure the 24 hour mode is enabled */
228	rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
229	if (rtc_time & RTC_HOURS_12H_MODE) {
230		dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
231		ret = -EINVAL;
232		goto out;
233	}
234
235	/* make sure it is actually functional */
236	if (rtc_time == 0x01000000) {
237		ssleep(1);
238		rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
239		if (rtc_time == 0x01000000) {
240			dev_err(&pdev->dev, "internal RTC not ticking\n");
241			ret = -ENODEV;
242			goto out;
243		}
244	}
245
246	pdata->irq = platform_get_irq(pdev, 0);
247
248	platform_set_drvdata(pdev, pdata);
249
250	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
251	if (IS_ERR(pdata->rtc)) {
252		ret = PTR_ERR(pdata->rtc);
253		goto out;
254	}
255
256	if (pdata->irq >= 0) {
257		writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
258		if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
259				     IRQF_SHARED,
260				     pdev->name, pdata) < 0) {
261			dev_warn(&pdev->dev, "interrupt not available.\n");
262			pdata->irq = -1;
263		}
264	}
265
266	if (pdata->irq >= 0)
267		device_init_wakeup(&pdev->dev, 1);
268	else
269		clear_bit(RTC_FEATURE_ALARM, pdata->rtc->features);
270
271	pdata->rtc->ops = &mv_rtc_ops;
272	pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
273	pdata->rtc->range_max = RTC_TIMESTAMP_END_2099;
274
275	ret = devm_rtc_register_device(pdata->rtc);
276	if (!ret)
277		return 0;
278out:
279	if (!IS_ERR(pdata->clk))
280		clk_disable_unprepare(pdata->clk);
281
282	return ret;
283}
284
285static void __exit mv_rtc_remove(struct platform_device *pdev)
286{
287	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
288
289	if (pdata->irq >= 0)
290		device_init_wakeup(&pdev->dev, 0);
291
292	if (!IS_ERR(pdata->clk))
293		clk_disable_unprepare(pdata->clk);
294}
295
296#ifdef CONFIG_OF
297static const struct of_device_id rtc_mv_of_match_table[] = {
298	{ .compatible = "marvell,orion-rtc", },
299	{}
300};
301MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
302#endif
303
304/*
305 * mv_rtc_remove() lives in .exit.text. For drivers registered via
306 * module_platform_driver_probe() this is ok because they cannot get unbound at
307 * runtime. So mark the driver struct with __refdata to prevent modpost
308 * triggering a section mismatch warning.
309 */
310static struct platform_driver mv_rtc_driver __refdata = {
311	.remove_new	= __exit_p(mv_rtc_remove),
312	.driver		= {
313		.name	= "rtc-mv",
314		.of_match_table = of_match_ptr(rtc_mv_of_match_table),
315	},
316};
317
318module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
319
320MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
321MODULE_DESCRIPTION("Marvell RTC driver");
322MODULE_LICENSE("GPL");
323MODULE_ALIAS("platform:rtc-mv");
324