diff options
Diffstat (limited to 'drivers/rtc/rtc-rtd119x.c')
| -rw-r--r-- | drivers/rtc/rtc-rtd119x.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rtd119x.c b/drivers/rtc/rtc-rtd119x.c new file mode 100644 index 000000000000..b233559d950b --- /dev/null +++ b/drivers/rtc/rtc-rtd119x.c @@ -0,0 +1,242 @@ +/* + * Realtek RTD129x RTC + * + * Copyright (c) 2017 Andreas Färber + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#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; + struct resource *res; + 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; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + data->base = devm_ioremap_resource(&pdev->dev, res); + 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 int 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); + + return 0; +} + +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); |