kernel/arch/x86/platform/olpc/olpc-xo1-rtc.c

   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);