Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
fe599f9f | 3 | * RTC related functions |
1da177e4 | 4 | */ |
8383d821 JSR |
5 | #include <linux/platform_device.h> |
6 | #include <linux/mc146818rtc.h> | |
69c60c88 | 7 | #include <linux/export.h> |
1da2e3d6 | 8 | #include <linux/pnp.h> |
1da177e4 | 9 | |
cdc7957d | 10 | #include <asm/vsyscall.h> |
7bd867df | 11 | #include <asm/x86_init.h> |
8383d821 | 12 | #include <asm/time.h> |
05454c26 | 13 | #include <asm/intel-mid.h> |
8d152e7a | 14 | #include <asm/setup.h> |
1da177e4 | 15 | |
1122b134 | 16 | #ifdef CONFIG_X86_32 |
1122b134 TG |
17 | /* |
18 | * This is a special lock that is owned by the CPU and holds the index | |
19 | * register we are working with. It is required for NMI access to the | |
fc04b2cc | 20 | * CMOS/RTC registers. See arch/x86/include/asm/mc146818rtc.h for details. |
1122b134 | 21 | */ |
8383d821 | 22 | volatile unsigned long cmos_lock; |
1122b134 | 23 | EXPORT_SYMBOL(cmos_lock); |
8383d821 | 24 | #endif /* CONFIG_X86_32 */ |
1122b134 TG |
25 | |
26 | DEFINE_SPINLOCK(rtc_lock); | |
27 | EXPORT_SYMBOL(rtc_lock); | |
28 | ||
1da177e4 | 29 | /* |
e1a6bc7c | 30 | * In order to set the CMOS clock precisely, mach_set_cmos_time has to be |
1da177e4 LT |
31 | * called 500 ms after the second nowtime has started, because when |
32 | * nowtime is written into the registers of the CMOS clock, it will | |
33 | * jump to the next second precisely 500 ms later. Check the Motorola | |
34 | * MC146818A or Dallas DS12887 data sheet for details. | |
1da177e4 | 35 | */ |
e1a6bc7c | 36 | int mach_set_cmos_time(const struct timespec64 *now) |
1da177e4 | 37 | { |
13cc36d7 | 38 | unsigned long long nowtime = now->tv_sec; |
3195ef59 | 39 | struct rtc_time tm; |
8383d821 | 40 | int retval = 0; |
1da177e4 | 41 | |
13cc36d7 | 42 | rtc_time64_to_tm(nowtime, &tm); |
3195ef59 | 43 | if (!rtc_valid_tm(&tm)) { |
463a8630 | 44 | retval = mc146818_set_time(&tm); |
3195ef59 PB |
45 | if (retval) |
46 | printk(KERN_ERR "%s: RTC write failed with error %d\n", | |
02f1f217 | 47 | __func__, retval); |
1da177e4 | 48 | } else { |
3195ef59 | 49 | printk(KERN_ERR |
13cc36d7 | 50 | "%s: Invalid RTC value: write of %llx to RTC failed\n", |
02f1f217 | 51 | __func__, nowtime); |
3195ef59 | 52 | retval = -EINVAL; |
1da177e4 | 53 | } |
1da177e4 LT |
54 | return retval; |
55 | } | |
56 | ||
e27c4929 | 57 | void mach_get_cmos_time(struct timespec64 *now) |
1da177e4 | 58 | { |
fc04b2cc | 59 | struct rtc_time tm; |
47997d75 | 60 | |
ba58d102 CY |
61 | /* |
62 | * If pm_trace abused the RTC as storage, set the timespec to 0, | |
63 | * which tells the caller that this RTC value is unusable. | |
64 | */ | |
65 | if (!pm_trace_rtc_valid()) { | |
66 | now->tv_sec = now->tv_nsec = 0; | |
67 | return; | |
68 | } | |
69 | ||
fc04b2cc MJ |
70 | if (mc146818_get_time(&tm)) { |
71 | pr_err("Unable to read current time from RTC\n"); | |
72 | now->tv_sec = now->tv_nsec = 0; | |
73 | return; | |
41623b06 MM |
74 | } |
75 | ||
fc04b2cc | 76 | now->tv_sec = rtc_tm_to_time64(&tm); |
3565184e | 77 | now->tv_nsec = 0; |
1da177e4 LT |
78 | } |
79 | ||
fe599f9f TG |
80 | /* Routines for accessing the CMOS RAM/RTC. */ |
81 | unsigned char rtc_cmos_read(unsigned char addr) | |
82 | { | |
83 | unsigned char val; | |
84 | ||
85 | lock_cmos_prefix(addr); | |
04aaa7ba DR |
86 | outb(addr, RTC_PORT(0)); |
87 | val = inb(RTC_PORT(1)); | |
fe599f9f | 88 | lock_cmos_suffix(addr); |
8383d821 | 89 | |
fe599f9f TG |
90 | return val; |
91 | } | |
92 | EXPORT_SYMBOL(rtc_cmos_read); | |
93 | ||
94 | void rtc_cmos_write(unsigned char val, unsigned char addr) | |
95 | { | |
96 | lock_cmos_prefix(addr); | |
04aaa7ba DR |
97 | outb(addr, RTC_PORT(0)); |
98 | outb(val, RTC_PORT(1)); | |
fe599f9f TG |
99 | lock_cmos_suffix(addr); |
100 | } | |
101 | EXPORT_SYMBOL(rtc_cmos_write); | |
102 | ||
e27c4929 | 103 | int update_persistent_clock64(struct timespec64 now) |
fe599f9f | 104 | { |
3565184e | 105 | return x86_platform.set_wallclock(&now); |
fe599f9f TG |
106 | } |
107 | ||
108 | /* not static: needed by APM */ | |
e27c4929 | 109 | void read_persistent_clock64(struct timespec64 *ts) |
fe599f9f | 110 | { |
3565184e | 111 | x86_platform.get_wallclock(ts); |
fe599f9f TG |
112 | } |
113 | ||
1da2e3d6 SS |
114 | |
115 | static struct resource rtc_resources[] = { | |
116 | [0] = { | |
117 | .start = RTC_PORT(0), | |
118 | .end = RTC_PORT(1), | |
119 | .flags = IORESOURCE_IO, | |
120 | }, | |
121 | [1] = { | |
122 | .start = RTC_IRQ, | |
123 | .end = RTC_IRQ, | |
124 | .flags = IORESOURCE_IRQ, | |
125 | } | |
126 | }; | |
127 | ||
128 | static struct platform_device rtc_device = { | |
129 | .name = "rtc_cmos", | |
130 | .id = -1, | |
131 | .resource = rtc_resources, | |
132 | .num_resources = ARRAY_SIZE(rtc_resources), | |
133 | }; | |
134 | ||
135 | static __init int add_rtc_cmos(void) | |
136 | { | |
137 | #ifdef CONFIG_PNP | |
d505ad1d | 138 | static const char * const ids[] __initconst = |
758a7f7b BH |
139 | { "PNP0b00", "PNP0b01", "PNP0b02", }; |
140 | struct pnp_dev *dev; | |
758a7f7b BH |
141 | int i; |
142 | ||
143 | pnp_for_each_dev(dev) { | |
bd4edba2 HG |
144 | for (i = 0; i < ARRAY_SIZE(ids); i++) { |
145 | if (compare_pnp_id(dev->id, ids[i]) != 0) | |
146 | return 0; | |
758a7f7b BH |
147 | } |
148 | } | |
149 | #endif | |
8d152e7a | 150 | if (!x86_platform.legacy.rtc) |
d8c98a1d DV |
151 | return -ENODEV; |
152 | ||
1da2e3d6 | 153 | platform_device_register(&rtc_device); |
758a7f7b BH |
154 | dev_info(&rtc_device.dev, |
155 | "registered platform RTC device (no PNP device found)\n"); | |
8383d821 | 156 | |
1da2e3d6 SS |
157 | return 0; |
158 | } | |
159 | device_initcall(add_rtc_cmos); |