xref: /openbmc/linux/drivers/rtc/rtc-starfire.c (revision 132db935)
1 /* rtc-starfire.c: Starfire platform RTC driver.
2  *
3  * Author: David S. Miller
4  * License: GPL
5  *
6  * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/rtc.h>
12 #include <linux/platform_device.h>
13 
14 #include <asm/oplib.h>
15 
16 static u32 starfire_get_time(void)
17 {
18 	static char obp_gettod[32];
19 	static u32 unix_tod;
20 
21 	sprintf(obp_gettod, "h# %08x unix-gettod",
22 		(unsigned int) (long) &unix_tod);
23 	prom_feval(obp_gettod);
24 
25 	return unix_tod;
26 }
27 
28 static int starfire_read_time(struct device *dev, struct rtc_time *tm)
29 {
30 	rtc_time64_to_tm(starfire_get_time(), tm);
31 	return 0;
32 }
33 
34 static const struct rtc_class_ops starfire_rtc_ops = {
35 	.read_time	= starfire_read_time,
36 };
37 
38 static int __init starfire_rtc_probe(struct platform_device *pdev)
39 {
40 	struct rtc_device *rtc;
41 
42 	rtc = devm_rtc_allocate_device(&pdev->dev);
43 	if (IS_ERR(rtc))
44 		return PTR_ERR(rtc);
45 
46 	rtc->ops = &starfire_rtc_ops;
47 	rtc->range_max = U32_MAX;
48 
49 	platform_set_drvdata(pdev, rtc);
50 
51 	return rtc_register_device(rtc);
52 }
53 
54 static struct platform_driver starfire_rtc_driver = {
55 	.driver		= {
56 		.name	= "rtc-starfire",
57 	},
58 };
59 
60 builtin_platform_driver_probe(starfire_rtc_driver, starfire_rtc_probe);
61