1 /*
2  * Support for OLPC XO-1 Real Time Clock (RTC)
3  *
4  * Copyright (C) 2011 One Laptop per Child
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/mc146818rtc.h>
13 #include <linux/platform_device.h>
14 #include <linux/rtc.h>
15 #include <linux/of.h>
16 
17 #include <asm/msr.h>
18 #include <asm/olpc.h>
19 
20 static void rtc_wake_on(struct device *dev)
21 {
22 	olpc_xo1_pm_wakeup_set(CS5536_PM_RTC);
23 }
24 
25 static void rtc_wake_off(struct device *dev)
26 {
27 	olpc_xo1_pm_wakeup_clear(CS5536_PM_RTC);
28 }
29 
30 static struct resource rtc_platform_resource[] = {
31 	[0] = {
32 		.start	= RTC_PORT(0),
33 		.end	= RTC_PORT(1),
34 		.flags	= IORESOURCE_IO,
35 	},
36 	[1] = {
37 		.start	= RTC_IRQ,
38 		.end	= RTC_IRQ,
39 		.flags	= IORESOURCE_IRQ,
40 	}
41 };
42 
43 static struct cmos_rtc_board_info rtc_info = {
44 	.rtc_day_alarm = 0,
45 	.rtc_mon_alarm = 0,
46 	.rtc_century = 0,
47 	.wake_on = rtc_wake_on,
48 	.wake_off = rtc_wake_off,
49 };
50 
51 static struct platform_device xo1_rtc_device = {
52 	.name = "rtc_cmos",
53 	.id = -1,
54 	.num_resources = ARRAY_SIZE(rtc_platform_resource),
55 	.dev.platform_data = &rtc_info,
56 	.resource = rtc_platform_resource,
57 };
58 
59 static int __init xo1_rtc_init(void)
60 {
61 	int r;
62 	struct device_node *node;
63 
64 	node = of_find_compatible_node(NULL, NULL, "olpc,xo1-rtc");
65 	if (!node)
66 		return 0;
67 	of_node_put(node);
68 
69 	pr_info("olpc-xo1-rtc: Initializing OLPC XO-1 RTC\n");
70 	rdmsrl(MSR_RTC_DOMA_OFFSET, rtc_info.rtc_day_alarm);
71 	rdmsrl(MSR_RTC_MONA_OFFSET, rtc_info.rtc_mon_alarm);
72 	rdmsrl(MSR_RTC_CEN_OFFSET, rtc_info.rtc_century);
73 
74 	r = platform_device_register(&xo1_rtc_device);
75 	if (r)
76 		return r;
77 
78 	device_init_wakeup(&xo1_rtc_device.dev, 1);
79 	return 0;
80 }
81 arch_initcall(xo1_rtc_init);
82