rtc-mv.c revision ea983ede1195982c64220e9030c28ff111c8655c 
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/gfp.h>
18#include <linux/module.h>
19
20
21#define RTC_TIME_REG_OFFS	0
22#define RTC_SECONDS_OFFS	0
23#define RTC_MINUTES_OFFS	8
24#define RTC_HOURS_OFFS		16
25#define RTC_WDAY_OFFS		24
26#define RTC_HOURS_12H_MODE		(1 << 22) /* 12 hours mode */
27
28#define RTC_DATE_REG_OFFS	4
29#define RTC_MDAY_OFFS		0
30#define RTC_MONTH_OFFS		8
31#define RTC_YEAR_OFFS		16
32
33#define RTC_ALARM_TIME_REG_OFFS	8
34#define RTC_ALARM_DATE_REG_OFFS	0xc
35#define RTC_ALARM_VALID		(1 << 7)
36
37#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS	0x10
38#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS	0x14
39
40struct rtc_plat_data {
41	struct rtc_device *rtc;
42	void __iomem *ioaddr;
43	int		irq;
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 hours 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 rtc_valid_tm(tm);
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 hours 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	if (rtc_valid_tm(&alm->time) < 0) {
126		dev_err(dev, "retrieved alarm date/time is not valid.\n");
127		rtc_time_to_tm(0, &alm->time);
128	}
129
130	alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
131	return 0;
132}
133
134static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
135{
136	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
137	void __iomem *ioaddr = pdata->ioaddr;
138	u32 rtc_reg = 0;
139
140	if (alm->time.tm_sec >= 0)
141		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
142			<< RTC_SECONDS_OFFS;
143	if (alm->time.tm_min >= 0)
144		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
145			<< RTC_MINUTES_OFFS;
146	if (alm->time.tm_hour >= 0)
147		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
148			<< RTC_HOURS_OFFS;
149
150	writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
151
152	if (alm->time.tm_mday >= 0)
153		rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
154			<< RTC_MDAY_OFFS;
155	else
156		rtc_reg = 0;
157
158	if (alm->time.tm_mon >= 0)
159		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
160			<< RTC_MONTH_OFFS;
161
162	if (alm->time.tm_year >= 0)
163		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
164			<< RTC_YEAR_OFFS;
165
166	writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
167	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
168	writel(alm->enabled ? 1 : 0,
169	       ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
170
171	return 0;
172}
173
174static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
175{
176	struct platform_device *pdev = to_platform_device(dev);
177	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
178	void __iomem *ioaddr = pdata->ioaddr;
179
180	if (pdata->irq < 0)
181		return -EINVAL; /* fall back into rtc-dev's emulation */
182
183	if (enabled)
184		writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
185	else
186		writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
187	return 0;
188}
189
190static irqreturn_t mv_rtc_interrupt(int irq, void *data)
191{
192	struct rtc_plat_data *pdata = data;
193	void __iomem *ioaddr = pdata->ioaddr;
194
195	/* alarm irq? */
196	if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
197		return IRQ_NONE;
198
199	/* clear interrupt */
200	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
201	rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
202	return IRQ_HANDLED;
203}
204
205static const struct rtc_class_ops mv_rtc_ops = {
206	.read_time	= mv_rtc_read_time,
207	.set_time	= mv_rtc_set_time,
208};
209
210static const struct rtc_class_ops mv_rtc_alarm_ops = {
211	.read_time	= mv_rtc_read_time,
212	.set_time	= mv_rtc_set_time,
213	.read_alarm	= mv_rtc_read_alarm,
214	.set_alarm	= mv_rtc_set_alarm,
215	.alarm_irq_enable = mv_rtc_alarm_irq_enable,
216};
217
218static int __devinit mv_rtc_probe(struct platform_device *pdev)
219{
220	struct resource *res;
221	struct rtc_plat_data *pdata;
222	resource_size_t size;
223	u32 rtc_time;
224
225	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
226	if (!res)
227		return -ENODEV;
228
229	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
230	if (!pdata)
231		return -ENOMEM;
232
233	size = resource_size(res);
234	if (!devm_request_mem_region(&pdev->dev, res->start, size,
235				     pdev->name))
236		return -EBUSY;
237
238	pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
239	if (!pdata->ioaddr)
240		return -ENOMEM;
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		return -EINVAL;
247	}
248
249	/* make sure it is actually functional */
250	if (rtc_time == 0x01000000) {
251		ssleep(1);
252		rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
253		if (rtc_time == 0x01000000) {
254			dev_err(&pdev->dev, "internal RTC not ticking\n");
255			return -ENODEV;
256		}
257	}
258
259	pdata->irq = platform_get_irq(pdev, 0);
260
261	platform_set_drvdata(pdev, pdata);
262
263	if (pdata->irq >= 0) {
264		device_init_wakeup(&pdev->dev, 1);
265		pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
266						 &mv_rtc_alarm_ops,
267						 THIS_MODULE);
268	} else
269		pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
270						 &mv_rtc_ops, THIS_MODULE);
271	if (IS_ERR(pdata->rtc))
272		return PTR_ERR(pdata->rtc);
273
274	if (pdata->irq >= 0) {
275		writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
276		if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
277				     IRQF_DISABLED | IRQF_SHARED,
278				     pdev->name, pdata) < 0) {
279			dev_warn(&pdev->dev, "interrupt not available.\n");
280			pdata->irq = -1;
281		}
282	}
283
284	return 0;
285}
286
287static int __exit mv_rtc_remove(struct platform_device *pdev)
288{
289	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
290
291	if (pdata->irq >= 0)
292		device_init_wakeup(&pdev->dev, 0);
293
294	rtc_device_unregister(pdata->rtc);
295	return 0;
296}
297
298#ifdef CONFIG_OF
299static struct of_device_id rtc_mv_of_match_table[] = {
300	{ .compatible = "mrvl,orion-rtc", },
301	{}
302};
303#endif
304
305static struct platform_driver mv_rtc_driver = {
306	.remove		= __exit_p(mv_rtc_remove),
307	.driver		= {
308		.name	= "rtc-mv",
309		.owner	= THIS_MODULE,
310		.of_match_table = of_match_ptr(rtc_mv_of_match_table),
311	},
312};
313
314static __init int mv_init(void)
315{
316	return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
317}
318
319static __exit void mv_exit(void)
320{
321	platform_driver_unregister(&mv_rtc_driver);
322}
323
324module_init(mv_init);
325module_exit(mv_exit);
326
327MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
328MODULE_DESCRIPTION("Marvell RTC driver");
329MODULE_LICENSE("GPL");
330MODULE_ALIAS("platform:rtc-mv");
331