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