mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-28 15:41:40 +00:00
2d6dc19fd2
The Goldfish RTC is a virtual device which may be supplied by QEMU. It is enabled by default on QEMU's RISC-V virt machine. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
105 lines
2.1 KiB
C
105 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright 2023, Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
|
|
*
|
|
* This driver emulates a real time clock based on timer ticks.
|
|
*/
|
|
|
|
#include <div64.h>
|
|
#include <dm.h>
|
|
#include <mapmem.h>
|
|
#include <rtc.h>
|
|
#include <linux/io.h>
|
|
|
|
/**
|
|
* struct goldfish_rtc - private data for RTC driver
|
|
*/
|
|
struct goldfish_rtc {
|
|
/**
|
|
* @base: base address for register file
|
|
*/
|
|
void __iomem *base;
|
|
/**
|
|
* @isdst: daylight saving time
|
|
*/
|
|
int isdst;
|
|
};
|
|
|
|
/* Register offsets */
|
|
#define GOLDFISH_TIME_LOW 0x00
|
|
#define GOLDFISH_TIME_HIGH 0x04
|
|
|
|
static int goldfish_rtc_get(struct udevice *dev, struct rtc_time *time)
|
|
{
|
|
struct goldfish_rtc *priv = dev_get_priv(dev);
|
|
void __iomem *base = priv->base;
|
|
u64 time_high;
|
|
u64 time_low;
|
|
u64 now;
|
|
|
|
time_low = ioread32(base + GOLDFISH_TIME_LOW);
|
|
time_high = ioread32(base + GOLDFISH_TIME_HIGH);
|
|
now = (time_high << 32) | time_low;
|
|
|
|
do_div(now, 1000000000U);
|
|
|
|
rtc_to_tm(now, time);
|
|
time->tm_isdst = priv->isdst;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int goldfish_rtc_set(struct udevice *dev, const struct rtc_time *time)
|
|
{
|
|
struct goldfish_rtc *priv = dev_get_priv(dev);
|
|
void __iomem *base = priv->base;
|
|
u64 now;
|
|
|
|
if (time->tm_year < 1970)
|
|
return -EINVAL;
|
|
|
|
now = rtc_mktime(time) * 1000000000ULL;
|
|
iowrite32(now >> 32, base + GOLDFISH_TIME_HIGH);
|
|
iowrite32(now, base + GOLDFISH_TIME_LOW);
|
|
|
|
if (time->tm_isdst > 0)
|
|
priv->isdst = 1;
|
|
else if (time->tm_isdst < 0)
|
|
priv->isdst = -1;
|
|
else
|
|
priv->isdst = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int goldfish_rtc_probe(struct udevice *dev)
|
|
{
|
|
struct goldfish_rtc *priv = dev_get_priv(dev);
|
|
fdt_addr_t addr;
|
|
|
|
addr = dev_read_addr(dev);
|
|
if (addr == FDT_ADDR_T_NONE)
|
|
return -EINVAL;
|
|
priv->base = map_sysmem(addr, 0x20);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_ops goldfish_rtc_ops = {
|
|
.get = goldfish_rtc_get,
|
|
.set = goldfish_rtc_set,
|
|
};
|
|
|
|
static const struct udevice_id goldfish_rtc_of_match[] = {
|
|
{ .compatible = "google,goldfish-rtc", },
|
|
{},
|
|
};
|
|
|
|
U_BOOT_DRIVER(rtc_goldfish) = {
|
|
.name = "rtc_goldfish",
|
|
.id = UCLASS_RTC,
|
|
.ops = &goldfish_rtc_ops,
|
|
.probe = goldfish_rtc_probe,
|
|
.of_match = goldfish_rtc_of_match,
|
|
.priv_auto = sizeof(struct goldfish_rtc),
|
|
};
|