#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/spinlock.h>
#define RTD_RTCSEC 0x00
#define RTD_RTCMIN 0x04
#define RTD_RTCHR 0x08
#define RTD_RTCDATE1 0x0c
#define RTD_RTCDATE2 0x10
#define RTD_RTCACR 0x28
#define RTD_RTCEN 0x2c
#define RTD_RTCCR 0x30
#define RTD_RTCSEC_RTCSEC_MASK 0x7f
#define RTD_RTCMIN_RTCMIN_MASK 0x3f
#define RTD_RTCHR_RTCHR_MASK 0x1f
#define RTD_RTCDATE1_RTCDATE1_MASK 0xff
#define RTD_RTCDATE2_RTCDATE2_MASK 0x7f
#define RTD_RTCACR_RTCPWR BIT(7)
#define RTD_RTCEN_RTCEN_MASK 0xff
#define RTD_RTCCR_RTCRST BIT(6)
struct rtd119x_rtc {
void __iomem *base;
struct clk *clk;
struct rtc_device *rtcdev;
unsigned int base_year;
};
static inline int rtd119x_rtc_days_in_year(int year)
{
return 365 + (is_leap_year(year) ? 1 : 0);
}
static void rtd119x_rtc_reset(struct device *dev)
{
struct rtd119x_rtc *data = dev_get_drvdata(dev);
u32 val;
val = readl_relaxed(data->base + RTD_RTCCR);
val |= RTD_RTCCR_RTCRST;
writel_relaxed(val, data->base + RTD_RTCCR);
val &= ~RTD_RTCCR_RTCRST;
writel(val, data->base + RTD_RTCCR);
}
static void rtd119x_rtc_set_enabled(struct device *dev, bool enable)
{
struct rtd119x_rtc *data = dev_get_drvdata(dev);
u32 val;
val = readl_relaxed(data->base + RTD_RTCEN);
if (enable) {
if ((val & RTD_RTCEN_RTCEN_MASK) == 0x5a)
return;
writel_relaxed(0x5a, data->base + RTD_RTCEN);
} else {
writel_relaxed(0, data->base + RTD_RTCEN);
}
}
static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct rtd119x_rtc *data = dev_get_drvdata(dev);
s32 day;
u32 sec;
unsigned int year;
int tries = 0;
while (true) {
tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;
tm->tm_min = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK;
tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK;
day = readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK;
day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8;
sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;
tries++;
if (sec == tm->tm_sec)
break;
if (tries >= 3)
return -EINVAL;
}
if (tries > 1)
dev_dbg(dev, "%s: needed %i tries\n", __func__, tries);
year = data->base_year;
while (day >= rtd119x_rtc_days_in_year(year)) {
day -= rtd119x_rtc_days_in_year(year);
year++;
}
tm->tm_year = year - 1900;
tm->tm_yday = day;
tm->tm_mon = 0;
while (day >= rtc_month_days(tm->tm_mon, year)) {
day -= rtc_month_days(tm->tm_mon, year);
tm->tm_mon++;
}
tm->tm_mday = day + 1;
return 0;
}
static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct rtd119x_rtc *data = dev_get_drvdata(dev);
unsigned int day;
int i;
if (1900 + tm->tm_year < data->base_year)
return -EINVAL;
day = 0;
for (i = data->base_year; i < 1900 + tm->tm_year; i++)
day += rtd119x_rtc_days_in_year(i);
day += tm->tm_yday;
if (day > 0x7fff)
return -EINVAL;
rtd119x_rtc_set_enabled(dev, false);
writel_relaxed((tm->tm_sec << 1) & RTD_RTCSEC_RTCSEC_MASK, data->base + RTD_RTCSEC);
writel_relaxed(tm->tm_min & RTD_RTCMIN_RTCMIN_MASK, data->base + RTD_RTCMIN);
writel_relaxed(tm->tm_hour & RTD_RTCHR_RTCHR_MASK, data->base + RTD_RTCHR);
writel_relaxed(day & RTD_RTCDATE1_RTCDATE1_MASK, data->base + RTD_RTCDATE1);
writel_relaxed((day >> 8) & RTD_RTCDATE2_RTCDATE2_MASK, data->base + RTD_RTCDATE2);
rtd119x_rtc_set_enabled(dev, true);
return 0;
}
static const struct rtc_class_ops rtd119x_rtc_ops = {
.read_time = rtd119x_rtc_read_time,
.set_time = rtd119x_rtc_set_time,
};
static const struct of_device_id rtd119x_rtc_dt_ids[] = {
{ .compatible = "realtek,rtd1295-rtc" },
{ }
};
static int rtd119x_rtc_probe(struct platform_device *pdev)
{
struct rtd119x_rtc *data;
u32 val;
int ret;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
platform_set_drvdata(pdev, data);
data->base_year = 2014;
data->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(data->base))
return PTR_ERR(data->base);
data->clk = of_clk_get(pdev->dev.of_node, 0);
if (IS_ERR(data->clk))
return PTR_ERR(data->clk);
ret = clk_prepare_enable(data->clk);
if (ret) {
clk_put(data->clk);
return ret;
}
val = readl_relaxed(data->base + RTD_RTCACR);
if (!(val & RTD_RTCACR_RTCPWR)) {
writel_relaxed(RTD_RTCACR_RTCPWR, data->base + RTD_RTCACR);
rtd119x_rtc_reset(&pdev->dev);
writel_relaxed(0, data->base + RTD_RTCMIN);
writel_relaxed(0, data->base + RTD_RTCHR);
writel_relaxed(0, data->base + RTD_RTCDATE1);
writel_relaxed(0, data->base + RTD_RTCDATE2);
}
rtd119x_rtc_set_enabled(&pdev->dev, true);
data->rtcdev = devm_rtc_device_register(&pdev->dev, "rtc",
&rtd119x_rtc_ops, THIS_MODULE);
if (IS_ERR(data->rtcdev)) {
dev_err(&pdev->dev, "failed to register rtc device");
clk_disable_unprepare(data->clk);
clk_put(data->clk);
return PTR_ERR(data->rtcdev);
}
return 0;
}
static void rtd119x_rtc_remove(struct platform_device *pdev)
{
struct rtd119x_rtc *data = platform_get_drvdata(pdev);
rtd119x_rtc_set_enabled(&pdev->dev, false);
clk_disable_unprepare(data->clk);
clk_put(data->clk);
}
static struct platform_driver rtd119x_rtc_driver = {
.probe = rtd119x_rtc_probe,
.remove = rtd119x_rtc_remove,
.driver = {
.name = "rtd1295-rtc",
.of_match_table = rtd119x_rtc_dt_ids,
},
};
builtin_platform_driver(rtd119x_rtc_driver);
