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 #include <asm/x86_init.h>
20 
21 static void rtc_wake_on(struct device *dev)
22 {
23 	olpc_xo1_pm_wakeup_set(CS5536_PM_RTC);
24 }
25 
26 static void rtc_wake_off(struct device *dev)
27 {
28 	olpc_xo1_pm_wakeup_clear(CS5536_PM_RTC);
29 }
30 
31 static struct resource rtc_platform_resource[] = {
32 	[0] = {
33 		.start	= RTC_PORT(0),
34 		.end	= RTC_PORT(1),
35 		.flags	= IORESOURCE_IO,
36 	},
37 	[1] = {
38 		.start	= RTC_IRQ,
39 		.end	= RTC_IRQ,
40 		.flags	= IORESOURCE_IRQ,
41 	}
42 };
43 
44 static struct cmos_rtc_board_info rtc_info = {
45 	.rtc_day_alarm = 0,
46 	.rtc_mon_alarm = 0,
47 	.rtc_century = 0,
48 	.wake_on = rtc_wake_on,
49 	.wake_off = rtc_wake_off,
50 };
51 
52 static struct platform_device xo1_rtc_device = {
53 	.name = "rtc_cmos",
54 	.id = -1,
55 	.num_resources = ARRAY_SIZE(rtc_platform_resource),
56 	.dev.platform_data = &rtc_info,
57 	.resource = rtc_platform_resource,
58 };
59 
60 static int __init xo1_rtc_init(void)
61 {
62 	int r;
63 	struct device_node *node;
64 
65 	node = of_find_compatible_node(NULL, NULL, "olpc,xo1-rtc");
66 	if (!node)
67 		return 0;
68 	of_node_put(node);
69 
70 	pr_info("olpc-xo1-rtc: Initializing OLPC XO-1 RTC\n");
71 	rdmsrl(MSR_RTC_DOMA_OFFSET, rtc_info.rtc_day_alarm);
72 	rdmsrl(MSR_RTC_MONA_OFFSET, rtc_info.rtc_mon_alarm);
73 	rdmsrl(MSR_RTC_CEN_OFFSET, rtc_info.rtc_century);
74 
75 	r = platform_device_register(&xo1_rtc_device);
76 	if (r)
77 		return r;
78 
79 	x86_platform.legacy.rtc = 0;
80 
81 	device_init_wakeup(&xo1_rtc_device.dev, 1);
82 	return 0;
83 }
84 arch_initcall(xo1_rtc_init);
85