1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
// SPDX-License-Identifier: GPL-2.0+
// Copyright 2015 IBM Corp.
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/io.h>
struct aspeed_rtc {
struct rtc_device *rtc_dev;
void __iomem *base;
};
#define RTC_TIME 0x00
#define RTC_YEAR 0x04
#define RTC_CTRL 0x10
#define RTC_UNLOCK BIT(1)
#define RTC_ENABLE BIT(0)
static int aspeed_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct aspeed_rtc *rtc = dev_get_drvdata(dev);
unsigned int cent, year;
u32 reg1, reg2;
if (!(readl(rtc->base + RTC_CTRL) & RTC_ENABLE)) {
dev_dbg(dev, "%s failing as rtc disabled\n", __func__);
return -EINVAL;
}
do {
reg2 = readl(rtc->base + RTC_YEAR);
reg1 = readl(rtc->base + RTC_TIME);
} while (reg2 != readl(rtc->base + RTC_YEAR));
tm->tm_mday = (reg1 >> 24) & 0x1f;
tm->tm_hour = (reg1 >> 16) & 0x1f;
tm->tm_min = (reg1 >> 8) & 0x3f;
tm->tm_sec = (reg1 >> 0) & 0x3f;
cent = (reg2 >> 16) & 0x1f;
year = (reg2 >> 8) & 0x7f;
tm->tm_mon = ((reg2 >> 0) & 0x0f) - 1;
tm->tm_year = year + (cent * 100) - 1900;
dev_dbg(dev, "%s %ptR", __func__, tm);
return 0;
}
static int aspeed_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct aspeed_rtc *rtc = dev_get_drvdata(dev);
u32 reg1, reg2, ctrl;
int year, cent;
cent = (tm->tm_year + 1900) / 100;
year = tm->tm_year % 100;
reg1 = (tm->tm_mday << 24) | (tm->tm_hour << 16) | (tm->tm_min << 8) |
tm->tm_sec;
reg2 = ((cent & 0x1f) << 16) | ((year & 0x7f) << 8) |
((tm->tm_mon + 1) & 0xf);
ctrl = readl(rtc->base + RTC_CTRL);
writel(ctrl | RTC_UNLOCK, rtc->base + RTC_CTRL);
writel(reg1, rtc->base + RTC_TIME);
writel(reg2, rtc->base + RTC_YEAR);
/* Re-lock and ensure enable is set now that a time is programmed */
writel(ctrl | RTC_ENABLE, rtc->base + RTC_CTRL);
return 0;
}
static const struct rtc_class_ops aspeed_rtc_ops = {
.read_time = aspeed_rtc_read_time,
.set_time = aspeed_rtc_set_time,
};
static int aspeed_rtc_probe(struct platform_device *pdev)
{
struct aspeed_rtc *rtc;
struct resource *res;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rtc->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(rtc->base))
return PTR_ERR(rtc->base);
rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc_dev))
return PTR_ERR(rtc->rtc_dev);
platform_set_drvdata(pdev, rtc);
rtc->rtc_dev->ops = &aspeed_rtc_ops;
rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900;
rtc->rtc_dev->range_max = 38814989399LL; /* 3199-12-31 23:59:59 */
ret = rtc_register_device(rtc->rtc_dev);
if (ret)
return ret;
return 0;
}
static const struct of_device_id aspeed_rtc_match[] = {
{ .compatible = "aspeed,ast2400-rtc", },
{ .compatible = "aspeed,ast2500-rtc", },
{ .compatible = "aspeed,ast2600-rtc", },
{}
};
MODULE_DEVICE_TABLE(of, aspeed_rtc_match);
static struct platform_driver aspeed_rtc_driver = {
.driver = {
.name = "aspeed-rtc",
.of_match_table = of_match_ptr(aspeed_rtc_match),
},
};
module_platform_driver_probe(aspeed_rtc_driver, aspeed_rtc_probe);
MODULE_DESCRIPTION("ASPEED RTC driver");
MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
MODULE_LICENSE("GPL");
|
