| 1 | |
| 2 | |
| 3 | *
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| 4 | * Author: David S. Miller
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| 5 | *
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| 6 | * Copyright (C) 2008 David S. Miller <[email protected]>
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| 7 |
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| 8 |
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| 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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| 10 |
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| 11 | #include <linux/kernel.h>
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| 12 | #include <linux/delay.h>
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| 13 | #include <linux/init.h>
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| 14 | #include <linux/rtc.h>
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| 15 | #include <linux/platform_device.h>
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| 16 |
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| 17 | #include <asm/hypervisor.h>
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| 18 |
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| 19 | static unsigned long hypervisor_get_time(void)
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| 20 | {
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| 21 | unsigned long ret, time;
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| 22 | int retries = 10000;
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| 23 |
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| 24 | retry:
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| 25 | ret = sun4v_tod_get(&time);
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| 26 | if (ret == HV_EOK)
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| 27 | return time;
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| 28 | if (ret == HV_EWOULDBLOCK) {
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| 29 | if (--retries > 0) {
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| 30 | udelay(100);
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| 31 | goto retry;
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| 32 | }
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| 33 | pr_warn("tod_get() timed out.\n");
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| 34 | return 0;
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| 35 | }
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| 36 | pr_warn("tod_get() not supported.\n");
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| 37 | return 0;
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| 38 | }
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| 39 |
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| 40 | static int sun4v_read_time(struct device *dev, struct rtc_time *tm)
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| 41 | {
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| 42 | rtc_time64_to_tm(hypervisor_get_time(), tm);
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| 43 | return 0;
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| 44 | }
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| 45 |
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| 46 | static int hypervisor_set_time(unsigned long secs)
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| 47 | {
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| 48 | unsigned long ret;
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| 49 | int retries = 10000;
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| 50 |
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| 51 | retry:
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| 52 | ret = sun4v_tod_set(secs);
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| 53 | if (ret == HV_EOK)
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| 54 | return 0;
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| 55 | if (ret == HV_EWOULDBLOCK) {
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| 56 | if (--retries > 0) {
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| 57 | udelay(100);
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| 58 | goto retry;
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| 59 | }
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| 60 | pr_warn("tod_set() timed out.\n");
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| 61 | return -EAGAIN;
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| 62 | }
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| 63 | pr_warn("tod_set() not supported.\n");
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| 64 | return -EOPNOTSUPP;
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| 65 | }
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| 66 |
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| 67 | static int sun4v_set_time(struct device *dev, struct rtc_time *tm)
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| 68 | {
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| 69 | return hypervisor_set_time(rtc_tm_to_time64(tm));
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| 70 | }
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| 71 |
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| 72 | static const struct rtc_class_ops sun4v_rtc_ops = {
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| 73 | .read_time = sun4v_read_time,
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| 74 | .set_time = sun4v_set_time,
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| 75 | };
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| 76 |
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| 77 | static int __init sun4v_rtc_probe(struct platform_device *pdev)
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| 78 | {
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| 79 | struct rtc_device *rtc;
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| 80 |
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| 81 | rtc = devm_rtc_allocate_device(&pdev->dev);
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| 82 | if (IS_ERR(rtc))
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| 83 | return PTR_ERR(rtc);
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| 84 |
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| 85 | rtc->ops = &sun4v_rtc_ops;
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| 86 | rtc->range_max = U64_MAX;
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| 87 | platform_set_drvdata(pdev, rtc);
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| 88 |
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| 89 | return devm_rtc_register_device(rtc);
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| 90 | }
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| 91 |
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| 92 | static struct platform_driver sun4v_rtc_driver = {
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| 93 | .driver = {
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| 94 | .name = "rtc-sun4v",
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| 95 | },
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| 96 | };
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| 97 |
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| 98 | builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);
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