rtc-mv.c revision aeedacaeaf9c02dddfeb6af87bef80c96f9050cb 
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/delay.h>
16
17
18#define RTC_TIME_REG_OFFS	0
19#define RTC_SECONDS_OFFS	0
20#define RTC_MINUTES_OFFS	8
21#define RTC_HOURS_OFFS		16
22#define RTC_WDAY_OFFS		24
23#define RTC_HOURS_12H_MODE		(1 << 22) /* 12 hours mode */
24
25#define RTC_DATE_REG_OFFS	4
26#define RTC_MDAY_OFFS		0
27#define RTC_MONTH_OFFS		8
28#define RTC_YEAR_OFFS		16
29
30#define RTC_ALARM_TIME_REG_OFFS	8
31#define RTC_ALARM_DATE_REG_OFFS	0xc
32#define RTC_ALARM_VALID		(1 << 7)
33
34#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS	0x10
35#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS	0x14
36
37struct rtc_plat_data {
38	struct rtc_device *rtc;
39	void __iomem *ioaddr;
40	int		irq;
41};
42
43static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
44{
45	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
46	void __iomem *ioaddr = pdata->ioaddr;
47	u32	rtc_reg;
48
49	rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
50		(bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
51		(bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
52		(bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
53	writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
54
55	rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
56		(bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
57		(bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
58	writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
59
60	return 0;
61}
62
63static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
64{
65	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
66	void __iomem *ioaddr = pdata->ioaddr;
67	u32	rtc_time, rtc_date;
68	unsigned int year, month, day, hour, minute, second, wday;
69
70	rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
71	rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
72
73	second = rtc_time & 0x7f;
74	minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
75	hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
76	wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
77
78	day = rtc_date & 0x3f;
79	month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
80	year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
81
82	tm->tm_sec = bcd2bin(second);
83	tm->tm_min = bcd2bin(minute);
84	tm->tm_hour = bcd2bin(hour);
85	tm->tm_mday = bcd2bin(day);
86	tm->tm_wday = bcd2bin(wday);
87	tm->tm_mon = bcd2bin(month) - 1;
88	/* hw counts from year 2000, but tm_year is relative to 1900 */
89	tm->tm_year = bcd2bin(year) + 100;
90
91	return rtc_valid_tm(tm);
92}
93
94static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
95{
96	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
97	void __iomem *ioaddr = pdata->ioaddr;
98	u32	rtc_time, rtc_date;
99	unsigned int year, month, day, hour, minute, second, wday;
100
101	rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
102	rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
103
104	second = rtc_time & 0x7f;
105	minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
106	hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
107	wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
108
109	day = rtc_date & 0x3f;
110	month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
111	year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
112
113	alm->time.tm_sec = bcd2bin(second);
114	alm->time.tm_min = bcd2bin(minute);
115	alm->time.tm_hour = bcd2bin(hour);
116	alm->time.tm_mday = bcd2bin(day);
117	alm->time.tm_wday = bcd2bin(wday);
118	alm->time.tm_mon = bcd2bin(month) - 1;
119	/* hw counts from year 2000, but tm_year is relative to 1900 */
120	alm->time.tm_year = bcd2bin(year) + 100;
121
122	if (rtc_valid_tm(&alm->time) < 0) {
123		dev_err(dev, "retrieved alarm date/time is not valid.\n");
124		rtc_time_to_tm(0, &alm->time);
125	}
126
127	alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
128	return 0;
129}
130
131static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
132{
133	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
134	void __iomem *ioaddr = pdata->ioaddr;
135	u32 rtc_reg = 0;
136
137	if (alm->time.tm_sec >= 0)
138		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
139			<< RTC_SECONDS_OFFS;
140	if (alm->time.tm_min >= 0)
141		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
142			<< RTC_MINUTES_OFFS;
143	if (alm->time.tm_hour >= 0)
144		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
145			<< RTC_HOURS_OFFS;
146
147	writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
148
149	if (alm->time.tm_mday >= 0)
150		rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
151			<< RTC_MDAY_OFFS;
152	else
153		rtc_reg = 0;
154
155	if (alm->time.tm_mon >= 0)
156		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
157			<< RTC_MONTH_OFFS;
158
159	if (alm->time.tm_year >= 0)
160		rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
161			<< RTC_YEAR_OFFS;
162
163	writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
164	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
165	writel(alm->enabled ? 1 : 0,
166	       ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
167
168	return 0;
169}
170
171static int mv_rtc_ioctl(struct device *dev, unsigned int cmd,
172			unsigned long arg)
173{
174	struct platform_device *pdev = to_platform_device(dev);
175	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
176	void __iomem *ioaddr = pdata->ioaddr;
177
178	if (pdata->irq < 0)
179		return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
180	switch (cmd) {
181	case RTC_AIE_OFF:
182		writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
183		break;
184	case RTC_AIE_ON:
185		writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
186		break;
187	default:
188		return -ENOIOCTLCMD;
189	}
190	return 0;
191}
192
193static irqreturn_t mv_rtc_interrupt(int irq, void *data)
194{
195	struct rtc_plat_data *pdata = data;
196	void __iomem *ioaddr = pdata->ioaddr;
197
198	/* alarm irq? */
199	if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
200		return IRQ_NONE;
201
202	/* clear interrupt */
203	writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
204	rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
205	return IRQ_HANDLED;
206}
207
208static const struct rtc_class_ops mv_rtc_ops = {
209	.read_time	= mv_rtc_read_time,
210	.set_time	= mv_rtc_set_time,
211};
212
213static const struct rtc_class_ops mv_rtc_alarm_ops = {
214	.read_time	= mv_rtc_read_time,
215	.set_time	= mv_rtc_set_time,
216	.read_alarm	= mv_rtc_read_alarm,
217	.set_alarm	= mv_rtc_set_alarm,
218	.ioctl		= mv_rtc_ioctl,
219};
220
221static int __devinit mv_rtc_probe(struct platform_device *pdev)
222{
223	struct resource *res;
224	struct rtc_plat_data *pdata;
225	resource_size_t size;
226	u32 rtc_time;
227
228	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
229	if (!res)
230		return -ENODEV;
231
232	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
233	if (!pdata)
234		return -ENOMEM;
235
236	size = resource_size(res);
237	if (!devm_request_mem_region(&pdev->dev, res->start, size,
238				     pdev->name))
239		return -EBUSY;
240
241	pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
242	if (!pdata->ioaddr)
243		return -ENOMEM;
244
245	/* make sure the 24 hours mode is enabled */
246	rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
247	if (rtc_time & RTC_HOURS_12H_MODE) {
248		dev_err(&pdev->dev, "24 Hours mode not supported.\n");
249		return -EINVAL;
250	}
251
252	/* make sure it is actually functional */
253	if (rtc_time == 0x01000000) {
254		ssleep(1);
255		rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
256		if (rtc_time == 0x01000000) {
257			dev_err(&pdev->dev, "internal RTC not ticking\n");
258			return -ENODEV;
259		}
260	}
261
262	pdata->irq = platform_get_irq(pdev, 0);
263
264	platform_set_drvdata(pdev, pdata);
265
266	if (pdata->irq >= 0) {
267		device_init_wakeup(&pdev->dev, 1);
268		pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
269						 &mv_rtc_alarm_ops,
270						 THIS_MODULE);
271	} else
272		pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
273						 &mv_rtc_ops, THIS_MODULE);
274	if (IS_ERR(pdata->rtc))
275		return PTR_ERR(pdata->rtc);
276
277	if (pdata->irq >= 0) {
278		writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
279		if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
280				     IRQF_DISABLED | IRQF_SHARED,
281				     pdev->name, pdata) < 0) {
282			dev_warn(&pdev->dev, "interrupt not available.\n");
283			pdata->irq = -1;
284		}
285	}
286
287	return 0;
288}
289
290static int __exit mv_rtc_remove(struct platform_device *pdev)
291{
292	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
293
294	if (pdata->irq >= 0)
295		device_init_wakeup(&pdev->dev, 0);
296
297	rtc_device_unregister(pdata->rtc);
298	return 0;
299}
300
301static struct platform_driver mv_rtc_driver = {
302	.remove		= __exit_p(mv_rtc_remove),
303	.driver		= {
304		.name	= "rtc-mv",
305		.owner	= THIS_MODULE,
306	},
307};
308
309static __init int mv_init(void)
310{
311	return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
312}
313
314static __exit void mv_exit(void)
315{
316	platform_driver_unregister(&mv_rtc_driver);
317}
318
319module_init(mv_init);
320module_exit(mv_exit);
321
322MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
323MODULE_DESCRIPTION("Marvell RTC driver");
324MODULE_LICENSE("GPL");
325MODULE_ALIAS("platform:rtc-mv");
326