projects / thirdparty / kernel / stable.git / blame
| Commit | Line | Data |
|---|---|---|
| 64bef02c | 1 | // SPDX-License-Identifier: GPL-2.0 |
| cecf61bd | 2 | /* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems. |
| 8b610253 PG |
3 | * |
| 4 | * Author: David S. Miller | |
| 7a138ede DM |
5 | * |
| 6 | * Copyright (C) 2008 David S. Miller <davem@davemloft.net> | |
| 7 | */ | |
| 8 | ||
| d959f731 JH |
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 10 | ||
| 7a138ede | 11 | #include <linux/kernel.h> |
| 7a138ede DM |
12 | #include <linux/delay.h> |
| 13 | #include <linux/init.h> | |
| 7a138ede DM |
14 | #include <linux/rtc.h> |
| 15 | #include <linux/platform_device.h> | |
| 16 | ||
| 17 | #include <asm/hypervisor.h> | |
| 18 | ||
| 7a138ede DM |
19 | static unsigned long hypervisor_get_time(void) |
| 20 | { | |
| 21 | unsigned long ret, time; | |
| 22 | int retries = 10000; | |
| 23 | ||
| 24 | retry: | |
| 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 | } | |
| d959f731 | 33 | pr_warn("tod_get() timed out.\n"); |
| 7a138ede DM |
34 | return 0; |
| 35 | } | |
| d959f731 | 36 | pr_warn("tod_get() not supported.\n"); |
| 7a138ede DM |
37 | return 0; |
| 38 | } | |
| 39 | ||
| 40 | static int sun4v_read_time(struct device *dev, struct rtc_time *tm) | |
| 41 | { | |
| 65c6f638 | 42 | rtc_time64_to_tm(hypervisor_get_time(), tm); |
| 7a138ede DM |
43 | return 0; |
| 44 | } | |
| 45 | ||
| 46 | static int hypervisor_set_time(unsigned long secs) | |
| 47 | { | |
| 48 | unsigned long ret; | |
| 49 | int retries = 10000; | |
| 50 | ||
| 51 | retry: | |
| 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 | } | |
| d959f731 | 60 | pr_warn("tod_set() timed out.\n"); |
| 7a138ede DM |
61 | return -EAGAIN; |
| 62 | } | |
| d959f731 | 63 | pr_warn("tod_set() not supported.\n"); |
| 7a138ede DM |
64 | return -EOPNOTSUPP; |
| 65 | } | |
| 66 | ||
| 67 | static int sun4v_set_time(struct device *dev, struct rtc_time *tm) | |
| 68 | { | |
| 65c6f638 | 69 | return hypervisor_set_time(rtc_tm_to_time64(tm)); |
| 7a138ede DM |
70 | } |
| 71 | ||
| 72 | static const struct rtc_class_ops sun4v_rtc_ops = { | |
| 73 | .read_time = sun4v_read_time, | |
| 74 | .set_time = sun4v_set_time, | |
| 75 | }; | |
| 76 | ||
| cecf61bd | 77 | static int __init sun4v_rtc_probe(struct platform_device *pdev) |
| 7a138ede | 78 | { |
| cc40d642 JH |
79 | struct rtc_device *rtc; |
| 80 | ||
| 3ec99d61 | 81 | rtc = devm_rtc_allocate_device(&pdev->dev); |
| cecf61bd AZ |
82 | if (IS_ERR(rtc)) |
| 83 | return PTR_ERR(rtc); | |
| 84 | ||
| 3ec99d61 AB |
85 | rtc->ops = &sun4v_rtc_ops; |
| 86 | rtc->range_max = U64_MAX; | |
| cecf61bd | 87 | platform_set_drvdata(pdev, rtc); |
| 3ec99d61 AB |
88 | |
| 89 | return rtc_register_device(rtc); | |
| 7a138ede DM |
90 | } |
| 91 | ||
| 7a138ede DM |
92 | static struct platform_driver sun4v_rtc_driver = { |
| 93 | .driver = { | |
| 94 | .name = "rtc-sun4v", | |
| 7a138ede | 95 | }, |
| 7a138ede DM |
96 | }; |
| 97 | ||
| 8b610253 | 98 | builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe); |