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 * Author: David S. Miller
  4 * License: GPL
  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_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);