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8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/delay.h>
13#include <linux/init.h>
14#include <linux/rtc.h>
15#include <linux/platform_device.h>
16
17#include <asm/hypervisor.h>
18
19static unsigned long hypervisor_get_time(void)
20{
21 unsigned long ret, time;
22 int retries = 10000;
23
24retry:
25 ret = sun4v_tod_get(&time);
26 if (ret == HV_EOK)
27 return time;
28 if (ret == HV_EWOULDBLOCK) {
29 if (--retries > 0) {
30 udelay(100);
31 goto retry;
32 }
33 pr_warn("tod_get() timed out.\n");
34 return 0;
35 }
36 pr_warn("tod_get() not supported.\n");
37 return 0;
38}
39
40static int sun4v_read_time(struct device *dev, struct rtc_time *tm)
41{
42 rtc_time_to_tm(hypervisor_get_time(), tm);
43 return 0;
44}
45
46static int hypervisor_set_time(unsigned long secs)
47{
48 unsigned long ret;
49 int retries = 10000;
50
51retry:
52 ret = sun4v_tod_set(secs);
53 if (ret == HV_EOK)
54 return 0;
55 if (ret == HV_EWOULDBLOCK) {
56 if (--retries > 0) {
57 udelay(100);
58 goto retry;
59 }
60 pr_warn("tod_set() timed out.\n");
61 return -EAGAIN;
62 }
63 pr_warn("tod_set() not supported.\n");
64 return -EOPNOTSUPP;
65}
66
67static int sun4v_set_time(struct device *dev, struct rtc_time *tm)
68{
69 unsigned long secs;
70 int err;
71
72 err = rtc_tm_to_time(tm, &secs);
73 if (err)
74 return err;
75
76 return hypervisor_set_time(secs);
77}
78
79static const struct rtc_class_ops sun4v_rtc_ops = {
80 .read_time = sun4v_read_time,
81 .set_time = sun4v_set_time,
82};
83
84static int __init sun4v_rtc_probe(struct platform_device *pdev)
85{
86 struct rtc_device *rtc;
87
88 rtc = devm_rtc_device_register(&pdev->dev, "sun4v",
89 &sun4v_rtc_ops, THIS_MODULE);
90 if (IS_ERR(rtc))
91 return PTR_ERR(rtc);
92
93 platform_set_drvdata(pdev, rtc);
94 return 0;
95}
96
97static struct platform_driver sun4v_rtc_driver = {
98 .driver = {
99 .name = "rtc-sun4v",
100 },
101};
102
103builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);
104
