1// SPDX-License-Identifier: GPL-2.0
 2/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
 3 *
 4 * Author: David S. Miller
 5 *
 6 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
 7 */
 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_time64_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	return hypervisor_set_time(rtc_tm_to_time64(tm));
 
 
 
 
 
 
 
70}
71
72static const struct rtc_class_ops sun4v_rtc_ops = {
73	.read_time	= sun4v_read_time,
74	.set_time	= sun4v_set_time,
75};
76
77static int __init sun4v_rtc_probe(struct platform_device *pdev)
78{
79	struct rtc_device *rtc;
80
81	rtc = devm_rtc_allocate_device(&pdev->dev);
 
82	if (IS_ERR(rtc))
83		return PTR_ERR(rtc);
84
85	rtc->ops = &sun4v_rtc_ops;
86	rtc->range_max = U64_MAX;
87	platform_set_drvdata(pdev, rtc);
88
89	return devm_rtc_register_device(rtc);
90}
91
92static struct platform_driver sun4v_rtc_driver = {
93	.driver		= {
94		.name	= "rtc-sun4v",
 
95	},
96};
97
98builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);
 
 
 
 

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