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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/rtc/rtc-sun4v.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/rtc/rtc-sun4v.c')
-rw-r--r-- | drivers/rtc/rtc-sun4v.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sun4v.c b/drivers/rtc/rtc-sun4v.c new file mode 100644 index 000000000..11bc562eb --- /dev/null +++ b/drivers/rtc/rtc-sun4v.c @@ -0,0 +1,103 @@ +/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems. + * + * Author: David S. Miller + * License: GPL + * + * Copyright (C) 2008 David S. Miller <davem@davemloft.net> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/rtc.h> +#include <linux/platform_device.h> + +#include <asm/hypervisor.h> + +static unsigned long hypervisor_get_time(void) +{ + unsigned long ret, time; + int retries = 10000; + +retry: + ret = sun4v_tod_get(&time); + if (ret == HV_EOK) + return time; + if (ret == HV_EWOULDBLOCK) { + if (--retries > 0) { + udelay(100); + goto retry; + } + pr_warn("tod_get() timed out.\n"); + return 0; + } + pr_warn("tod_get() not supported.\n"); + return 0; +} + +static int sun4v_read_time(struct device *dev, struct rtc_time *tm) +{ + rtc_time_to_tm(hypervisor_get_time(), tm); + return 0; +} + +static int hypervisor_set_time(unsigned long secs) +{ + unsigned long ret; + int retries = 10000; + +retry: + ret = sun4v_tod_set(secs); + if (ret == HV_EOK) + return 0; + if (ret == HV_EWOULDBLOCK) { + if (--retries > 0) { + udelay(100); + goto retry; + } + pr_warn("tod_set() timed out.\n"); + return -EAGAIN; + } + pr_warn("tod_set() not supported.\n"); + return -EOPNOTSUPP; +} + +static int sun4v_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long secs; + int err; + + err = rtc_tm_to_time(tm, &secs); + if (err) + return err; + + return hypervisor_set_time(secs); +} + +static const struct rtc_class_ops sun4v_rtc_ops = { + .read_time = sun4v_read_time, + .set_time = sun4v_set_time, +}; + +static int __init sun4v_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_device_register(&pdev->dev, "sun4v", + &sun4v_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + platform_set_drvdata(pdev, rtc); + return 0; +} + +static struct platform_driver sun4v_rtc_driver = { + .driver = { + .name = "rtc-sun4v", + }, +}; + +builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe); |