rtc-mv.c revision e102dc7a5498439bf72ae9f6457f2e7fe09a4ae0 
1/*
2 * Driver for the RTC in Marvell SoCs.
3 *
4 * This file is licensed under the terms of the GNU General Public
5 * License version 2.  This program is licensed "as is" without any
6 * warranty of any kind, whether express or implied.
7 */
8
9#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/rtc.h>
12#include <linux/bcd.h>
13#include <linux/io.h>
14#include <linux/platform_device.h>
15#include <linux/of.h>
16#include <linux/delay.h>
17#include <linux/clk.h>
18#include <linux/gfp.h>
19#include <linux/module.h>
20
21
22#define RTC_TIME_REG_OFFS	0
23#define RTC_SECONDS_OFFS	0
24#define RTC_MINUTES_OFFS	8
25#define RTC_HOURS_OFFS		16
26#define RTC_WDAY_OFFS		24
27#define RTC_HOURS_12H_MODE		(1 << 22) /* 12 hours mode */
28
29#define RTC_DATE_REG_OFFS	4
30#define RTC_MDAY_OFFS		0
31#define RTC_MONTH_OFFS		8
32#define RTC_YEAR_OFFS		16
33
34#define RTC_ALARM_TIME_REG_OFFS	8
35#define RTC_ALARM_DATE_REG_OFFS	0xc
36#define RTC_ALARM_VALID		(1 << 7)
37
38#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS	0x10
39#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS	0x14
40
41struct rtc_plat_data {
42	struct rtc_device *rtc;
43	void __iomem *ioaddr;
44	int		irq;
45	struct clk	*clk;
46};
47
48static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
49{
50	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
51	void __iomem *ioaddr = pdata->ioaddr;
52	u32	rtc_reg;
53
54	rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
55		(bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
56		(bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
57		(bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
58	writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
59
60	rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
61		(bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
62		(bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
63	writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
64
65	return 0;
66}
67
68static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
69{
70	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
71	void __iomem *ioaddr = pdata->ioaddr;
72	u32	rtc_time, rtc_date;
73	unsigned int year, month, day, hour, minute, second, wday;
74
75	rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
76	rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
77
78	second = rtc_time & 0x7f;
79	minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
80	hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
81	wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
82
83	day = rtc_date & 0x3f;
84	month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
85	year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
86
87	tm->tm_sec = bcd2bin(second);
88	tm->tm_min = bcd2bin(minute);
89	tm->tm_hour = bcd2bin(hour);
90	tm->tm_mday = bcd2bin(day);
91	tm->tm_wday = bcd2bin(wday);
92	tm->tm_mon = bcd2bin(month) - 1;
93	/* hw counts from year 2000, but tm_year is relative to 1900 */
94	tm->tm_year = bcd2bin(year) + 100;
95
96	return rtc_valid_tm(tm);
97}
98
99static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
100{
101	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
102	void __iomem *ioaddr = pdata->ioaddr;
103	u32	rtc_time, rtc_date;
104	unsigned int year, month, day, hour, minute, second, wday;
105
106	rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
107	rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
108
109	second = rtc_time & 0x7f;
110	minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
111	hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
112	wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
113
114	day = rtc_date & 0x3f;
115	month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
116	year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
117
118	alm->time.tm_sec = bcd2bin(second);
119	alm->time.tm_min = bcd2bin(minute);
120	alm->time.tm_hour = bcd2bin(hour);
121	alm->time.tm_mday = bcd2bin(day);
122	alm->time.tm_wday = bcd2bin(wday);
123	alm->time.tm_mon = bcd2bin(month) - 1;
124	/* hw counts from year 2000, but tm_year is relative to 1900 */
125	alm->time.tm_year = bcd2bin(year) + 100;
126
127	if (rtc_valid_tm(&alm->time) < 0) {
128		dev_err(dev, "retrieved alarm date/time is not valid.\n");
129		rtc_time_to_tm(0, &alm->time);
130	}
131
132	alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
133	return 0;
134}
135
136static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
137{
138	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
139	void __iomem *ioaddr = pdata->ioaddr;
140	u32 rtc_reg = 0;
141
142	if (alm->time.tm_sec >= 0)
143		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
144			<< RTC_SECONDS_OFFS;
145	if (alm->time.tm_min >= 0)
146		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
147			<< RTC_MINUTES_OFFS;
148	if (alm->time.tm_hour >= 0)
149		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
150			<< RTC_HOURS_OFFS;
151
152	writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
153
154	if (alm->time.tm_mday >= 0)
155		rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
156			<< RTC_MDAY_OFFS;
157	else
158		rtc_reg = 0;
159
160	if (alm->time.tm_mon >= 0)
161		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
162			<< RTC_MONTH_OFFS;
163
164	if (alm->time.tm_year >= 0)
165		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
166			<< RTC_YEAR_OFFS;
167
168	writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
169	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
170	writel(alm->enabled ? 1 : 0,
171	       ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
172
173	return 0;
174}
175
176static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
177{
178	struct platform_device *pdev = to_platform_device(dev);
179	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
180	void __iomem *ioaddr = pdata->ioaddr;
181
182	if (pdata->irq < 0)
183		return -EINVAL; /* fall back into rtc-dev's emulation */
184
185	if (enabled)
186		writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
187	else
188		writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
189	return 0;
190}
191
192static irqreturn_t mv_rtc_interrupt(int irq, void *data)
193{
194	struct rtc_plat_data *pdata = data;
195	void __iomem *ioaddr = pdata->ioaddr;
196
197	/* alarm irq? */
198	if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
199		return IRQ_NONE;
200
201	/* clear interrupt */
202	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
203	rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
204	return IRQ_HANDLED;
205}
206
207static const struct rtc_class_ops mv_rtc_ops = {
208	.read_time	= mv_rtc_read_time,
209	.set_time	= mv_rtc_set_time,
210};
211
212static const struct rtc_class_ops mv_rtc_alarm_ops = {
213	.read_time	= mv_rtc_read_time,
214	.set_time	= mv_rtc_set_time,
215	.read_alarm	= mv_rtc_read_alarm,
216	.set_alarm	= mv_rtc_set_alarm,
217	.alarm_irq_enable = mv_rtc_alarm_irq_enable,
218};
219
220static int __init mv_rtc_probe(struct platform_device *pdev)
221{
222	struct resource *res;
223	struct rtc_plat_data *pdata;
224	u32 rtc_time;
225	u32 rtc_date;
226	int ret = 0;
227
228	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
229	if (!pdata)
230		return -ENOMEM;
231
232	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
233	pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
234	if (IS_ERR(pdata->ioaddr))
235		return PTR_ERR(pdata->ioaddr);
236
237	pdata->clk = devm_clk_get(&pdev->dev, NULL);
238	/* Not all SoCs require a clock.*/
239	if (!IS_ERR(pdata->clk))
240		clk_prepare_enable(pdata->clk);
241
242	/* make sure the 24 hours mode is enabled */
243	rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
244	if (rtc_time & RTC_HOURS_12H_MODE) {
245		dev_err(&pdev->dev, "24 Hours mode not supported.\n");
246		ret = -EINVAL;
247		goto out;
248	}
249
250	/* make sure it is actually functional */
251	if (rtc_time == 0x01000000) {
252		ssleep(1);
253		rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
254		if (rtc_time == 0x01000000) {
255			dev_err(&pdev->dev, "internal RTC not ticking\n");
256			ret = -ENODEV;
257			goto out;
258		}
259	}
260
261	/*
262	 * A date after January 19th, 2038 does not fit on 32 bits and
263	 * will confuse the kernel and userspace. Reset to a sane date
264	 * (January 1st, 2013) if we're after 2038.
265	 */
266	rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS);
267	if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) {
268		dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n");
269		writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS);
270	}
271
272	pdata->irq = platform_get_irq(pdev, 0);
273
274	platform_set_drvdata(pdev, pdata);
275
276	if (pdata->irq >= 0) {
277		device_init_wakeup(&pdev->dev, 1);
278		pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
279						 &mv_rtc_alarm_ops,
280						 THIS_MODULE);
281	} else {
282		pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
283						 &mv_rtc_ops, THIS_MODULE);
284	}
285	if (IS_ERR(pdata->rtc)) {
286		ret = PTR_ERR(pdata->rtc);
287		goto out;
288	}
289
290	if (pdata->irq >= 0) {
291		writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
292		if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
293				     IRQF_SHARED,
294				     pdev->name, pdata) < 0) {
295			dev_warn(&pdev->dev, "interrupt not available.\n");
296			pdata->irq = -1;
297		}
298	}
299
300	return 0;
301out:
302	if (!IS_ERR(pdata->clk))
303		clk_disable_unprepare(pdata->clk);
304
305	return ret;
306}
307
308static int __exit mv_rtc_remove(struct platform_device *pdev)
309{
310	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
311
312	if (pdata->irq >= 0)
313		device_init_wakeup(&pdev->dev, 0);
314
315	if (!IS_ERR(pdata->clk))
316		clk_disable_unprepare(pdata->clk);
317
318	return 0;
319}
320
321#ifdef CONFIG_OF
322static struct of_device_id rtc_mv_of_match_table[] = {
323	{ .compatible = "marvell,orion-rtc", },
324	{}
325};
326#endif
327
328static struct platform_driver mv_rtc_driver = {
329	.remove		= __exit_p(mv_rtc_remove),
330	.driver		= {
331		.name	= "rtc-mv",
332		.owner	= THIS_MODULE,
333		.of_match_table = of_match_ptr(rtc_mv_of_match_table),
334	},
335};
336
337module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
338
339MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
340MODULE_DESCRIPTION("Marvell RTC driver");
341MODULE_LICENSE("GPL");
342MODULE_ALIAS("platform:rtc-mv");
343