mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-25 03:55:09 +08:00
184a182ed5
Read and writes the time to the non-battery backed RTC in the ASPEED BMC system on chip families. Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
137 lines
3.2 KiB
C
137 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
// Copyright 2015 IBM Corp.
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/io.h>
|
|
|
|
struct aspeed_rtc {
|
|
struct rtc_device *rtc_dev;
|
|
void __iomem *base;
|
|
};
|
|
|
|
#define RTC_TIME 0x00
|
|
#define RTC_YEAR 0x04
|
|
#define RTC_CTRL 0x10
|
|
|
|
#define RTC_UNLOCK BIT(1)
|
|
#define RTC_ENABLE BIT(0)
|
|
|
|
static int aspeed_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct aspeed_rtc *rtc = dev_get_drvdata(dev);
|
|
unsigned int cent, year;
|
|
u32 reg1, reg2;
|
|
|
|
if (!(readl(rtc->base + RTC_CTRL) & RTC_ENABLE)) {
|
|
dev_dbg(dev, "%s failing as rtc disabled\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
do {
|
|
reg2 = readl(rtc->base + RTC_YEAR);
|
|
reg1 = readl(rtc->base + RTC_TIME);
|
|
} while (reg2 != readl(rtc->base + RTC_YEAR));
|
|
|
|
tm->tm_mday = (reg1 >> 24) & 0x1f;
|
|
tm->tm_hour = (reg1 >> 16) & 0x1f;
|
|
tm->tm_min = (reg1 >> 8) & 0x3f;
|
|
tm->tm_sec = (reg1 >> 0) & 0x3f;
|
|
|
|
cent = (reg2 >> 16) & 0x1f;
|
|
year = (reg2 >> 8) & 0x7f;
|
|
tm->tm_mon = ((reg2 >> 0) & 0x0f) - 1;
|
|
tm->tm_year = year + (cent * 100) - 1900;
|
|
|
|
dev_dbg(dev, "%s %ptR", __func__, tm);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int aspeed_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct aspeed_rtc *rtc = dev_get_drvdata(dev);
|
|
u32 reg1, reg2, ctrl;
|
|
int year, cent;
|
|
|
|
cent = (tm->tm_year + 1900) / 100;
|
|
year = tm->tm_year % 100;
|
|
|
|
reg1 = (tm->tm_mday << 24) | (tm->tm_hour << 16) | (tm->tm_min << 8) |
|
|
tm->tm_sec;
|
|
|
|
reg2 = ((cent & 0x1f) << 16) | ((year & 0x7f) << 8) |
|
|
((tm->tm_mon + 1) & 0xf);
|
|
|
|
ctrl = readl(rtc->base + RTC_CTRL);
|
|
writel(ctrl | RTC_UNLOCK, rtc->base + RTC_CTRL);
|
|
|
|
writel(reg1, rtc->base + RTC_TIME);
|
|
writel(reg2, rtc->base + RTC_YEAR);
|
|
|
|
/* Re-lock and ensure enable is set now that a time is programmed */
|
|
writel(ctrl | RTC_ENABLE, rtc->base + RTC_CTRL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops aspeed_rtc_ops = {
|
|
.read_time = aspeed_rtc_read_time,
|
|
.set_time = aspeed_rtc_set_time,
|
|
};
|
|
|
|
static int aspeed_rtc_probe(struct platform_device *pdev)
|
|
{
|
|
struct aspeed_rtc *rtc;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
|
|
if (!rtc)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
rtc->base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(rtc->base))
|
|
return PTR_ERR(rtc->base);
|
|
|
|
rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
|
|
if (IS_ERR(rtc->rtc_dev))
|
|
return PTR_ERR(rtc->rtc_dev);
|
|
|
|
platform_set_drvdata(pdev, rtc);
|
|
|
|
rtc->rtc_dev->ops = &aspeed_rtc_ops;
|
|
rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900;
|
|
rtc->rtc_dev->range_max = 38814989399LL; /* 3199-12-31 23:59:59 */
|
|
|
|
ret = rtc_register_device(rtc->rtc_dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id aspeed_rtc_match[] = {
|
|
{ .compatible = "aspeed,ast2400-rtc", },
|
|
{ .compatible = "aspeed,ast2500-rtc", },
|
|
{ .compatible = "aspeed,ast2600-rtc", },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, aspeed_rtc_match);
|
|
|
|
static struct platform_driver aspeed_rtc_driver = {
|
|
.driver = {
|
|
.name = "aspeed-rtc",
|
|
.of_match_table = of_match_ptr(aspeed_rtc_match),
|
|
},
|
|
};
|
|
|
|
module_platform_driver_probe(aspeed_rtc_driver, aspeed_rtc_probe);
|
|
|
|
MODULE_DESCRIPTION("ASPEED RTC driver");
|
|
MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
|
|
MODULE_LICENSE("GPL");
|