tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
2 *
3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
4 */
5
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/delay.h>
9#include <linux/init.h>
10#include <linux/rtc.h>
11#include <linux/platform_device.h>
12
13#include <asm/hypervisor.h>
14
15static unsigned long hypervisor_get_time(void)
16{
17 unsigned long ret, time;
18 int retries = 10000;
19
20retry:
21 ret = sun4v_tod_get(&time);
22 if (ret == HV_EOK)
23 return time;
24 if (ret == HV_EWOULDBLOCK) {
25 if (--retries > 0) {
26 udelay(100);
27 goto retry;
28 }
29 printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
30 return 0;
31 }
32 printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
33 return 0;
34}
35
36static int sun4v_read_time(struct device *dev, struct rtc_time *tm)
37{
38 rtc_time_to_tm(hypervisor_get_time(), tm);
39 return 0;
40}
41
42static int hypervisor_set_time(unsigned long secs)
43{
44 unsigned long ret;
45 int retries = 10000;
46
47retry:
48 ret = sun4v_tod_set(secs);
49 if (ret == HV_EOK)
50 return 0;
51 if (ret == HV_EWOULDBLOCK) {
52 if (--retries > 0) {
53 udelay(100);
54 goto retry;
55 }
56 printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
57 return -EAGAIN;
58 }
59 printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
60 return -EOPNOTSUPP;
61}
62
63static int sun4v_set_time(struct device *dev, struct rtc_time *tm)
64{
65 unsigned long secs;
66 int err;
67
68 err = rtc_tm_to_time(tm, &secs);
69 if (err)
70 return err;
71
72 return hypervisor_set_time(secs);
73}
74
75static const struct rtc_class_ops sun4v_rtc_ops = {
76 .read_time = sun4v_read_time,
77 .set_time = sun4v_set_time,
78};
79
80static int __init sun4v_rtc_probe(struct platform_device *pdev)
81{
82 struct rtc_device *rtc = rtc_device_register("sun4v", &pdev->dev,
83 &sun4v_rtc_ops, THIS_MODULE);
84 if (IS_ERR(rtc))
85 return PTR_ERR(rtc);
86
87 platform_set_drvdata(pdev, rtc);
88 return 0;
89}
90
91static int __exit sun4v_rtc_remove(struct platform_device *pdev)
92{
93 struct rtc_device *rtc = platform_get_drvdata(pdev);
94
95 rtc_device_unregister(rtc);
96 return 0;
97}
98
99static struct platform_driver sun4v_rtc_driver = {
100 .driver = {
101 .name = "rtc-sun4v",
102 .owner = THIS_MODULE,
103 },
104 .remove = __exit_p(sun4v_rtc_remove),
105};
106
107static int __init sun4v_rtc_init(void)
108{
109 return platform_driver_probe(&sun4v_rtc_driver, sun4v_rtc_probe);
110}
111
112static void __exit sun4v_rtc_exit(void)
113{
114 platform_driver_unregister(&sun4v_rtc_driver);
115}
116
117module_init(sun4v_rtc_init);
118module_exit(sun4v_rtc_exit);
119
120MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
121MODULE_DESCRIPTION("SUN4V RTC driver");
122MODULE_LICENSE("GPL");