--- /dev/null
+/*
+ * 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);
projects / linux.git / commitdiff