xref: /openbmc/linux/drivers/rtc/rtc-generic.c (revision 78700c0a)
1 /* rtc-generic: RTC driver using the generic RTC abstraction
2  *
3  * Copyright (C) 2008 Kyle McMartin <kyle@mcmartin.ca>
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/time.h>
9 #include <linux/platform_device.h>
10 #include <linux/rtc.h>
11 
12 #if defined(CONFIG_M68K) || defined(CONFIG_PARISC) || \
13     defined(CONFIG_PPC) || defined(CONFIG_SUPERH32)
14 #include <asm/rtc.h>
15 
16 static int generic_get_time(struct device *dev, struct rtc_time *tm)
17 {
18 	unsigned int ret = get_rtc_time(tm);
19 
20 	if (ret & RTC_BATT_BAD)
21 		return -EOPNOTSUPP;
22 
23 	return rtc_valid_tm(tm);
24 }
25 
26 static int generic_set_time(struct device *dev, struct rtc_time *tm)
27 {
28 	if (set_rtc_time(tm) < 0)
29 		return -EOPNOTSUPP;
30 
31 	return 0;
32 }
33 
34 static const struct rtc_class_ops generic_rtc_ops = {
35 	.read_time = generic_get_time,
36 	.set_time = generic_set_time,
37 };
38 #else
39 #define generic_rtc_ops *(struct rtc_class_ops*)NULL
40 #endif
41 
42 static int __init generic_rtc_probe(struct platform_device *dev)
43 {
44 	struct rtc_device *rtc;
45 	const struct rtc_class_ops *ops;
46 
47 	ops = dev_get_platdata(&dev->dev);
48 	if (!ops)
49 		ops = &generic_rtc_ops;
50 
51 	rtc = devm_rtc_device_register(&dev->dev, "rtc-generic",
52 					ops, THIS_MODULE);
53 	if (IS_ERR(rtc))
54 		return PTR_ERR(rtc);
55 
56 	platform_set_drvdata(dev, rtc);
57 
58 	return 0;
59 }
60 
61 static struct platform_driver generic_rtc_driver = {
62 	.driver = {
63 		.name = "rtc-generic",
64 	},
65 };
66 
67 module_platform_driver_probe(generic_rtc_driver, generic_rtc_probe);
68 
69 MODULE_AUTHOR("Kyle McMartin <kyle@mcmartin.ca>");
70 MODULE_LICENSE("GPL");
71 MODULE_DESCRIPTION("Generic RTC driver");
72 MODULE_ALIAS("platform:rtc-generic");
73