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

   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);