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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/rtc/rtc-sun4v.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
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 | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sun4v.c b/drivers/rtc/rtc-sun4v.c new file mode 100644 index 000000000..036463dfa --- /dev/null +++ b/drivers/rtc/rtc-sun4v.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems. + * + * Author: David S. Miller + * + * 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_time64_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) +{ + return hypervisor_set_time(rtc_tm_to_time64(tm)); +} + +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_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &sun4v_rtc_ops; + rtc->range_max = U64_MAX; + platform_set_drvdata(pdev, rtc); + + return rtc_register_device(rtc); +} + +static struct platform_driver sun4v_rtc_driver = { + .driver = { + .name = "rtc-sun4v", + }, +}; + +builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe); |