1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Support for OLPC XO-1 Real Time Clock (RTC)
4 *
5 * Copyright (C) 2011 One Laptop per Child
6 */
7
8 #include <linux/mc146818rtc.h>
9 #include <linux/platform_device.h>
10 #include <linux/rtc.h>
11 #include <linux/of.h>
12
13 #include <asm/msr.h>
14 #include <asm/olpc.h>
15 #include <asm/x86_init.h>
16
17 static void rtc_wake_on(struct device *dev)
18 {
19 olpc_xo1_pm_wakeup_set(CS5536_PM_RTC);
20 }
21
22 static void rtc_wake_off(struct device *dev)
23 {
24 olpc_xo1_pm_wakeup_clear(CS5536_PM_RTC);
25 }
26
27 static struct resource rtc_platform_resource[] = {
28 [0] = {
29 .start = RTC_PORT(0),
30 .end = RTC_PORT(1),
31 .flags = IORESOURCE_IO,
32 },
33 [1] = {
34 .start = RTC_IRQ,
35 .end = RTC_IRQ,
36 .flags = IORESOURCE_IRQ,
37 }
38 };
39
40 static struct cmos_rtc_board_info rtc_info = {
41 .rtc_day_alarm = 0,
42 .rtc_mon_alarm = 0,
43 .rtc_century = 0,
44 .wake_on = rtc_wake_on,
45 .wake_off = rtc_wake_off,
46 };
47
48 static struct platform_device xo1_rtc_device = {
49 .name = "rtc_cmos",
50 .id = -1,
51 .num_resources = ARRAY_SIZE(rtc_platform_resource),
52 .dev.platform_data = &rtc_info,
53 .resource = rtc_platform_resource,
54 };
55
56 static int __init xo1_rtc_init(void)
57 {
58 int r;
59 struct device_node *node;
60
61 node = of_find_compatible_node(NULL, NULL, "olpc,xo1-rtc");
62 if (!node)
63 return 0;
64 of_node_put(node);
65
66 pr_info("olpc-xo1-rtc: Initializing OLPC XO-1 RTC\n");
67 rdmsrl(MSR_RTC_DOMA_OFFSET, rtc_info.rtc_day_alarm);
68 rdmsrl(MSR_RTC_MONA_OFFSET, rtc_info.rtc_mon_alarm);
69 rdmsrl(MSR_RTC_CEN_OFFSET, rtc_info.rtc_century);
70
71 r = platform_device_register(&xo1_rtc_device);
72 if (r)
73 return r;
74
75 x86_platform.legacy.rtc = 0;
76
77 device_init_wakeup(&xo1_rtc_device.dev, 1);
78 return 0;
79 }
80 arch_initcall(xo1_rtc_init);
81
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