rtc: Add Realtek RTD1295
authorAndreas Färber <afaerber@suse.de>
Mon, 4 Sep 2017 22:53:23 +0000 (00:53 +0200)
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>
Tue, 5 Sep 2017 07:55:02 +0000 (09:55 +0200)
Based on QNAP's arch/arm/mach-rtk119x/driver/rtk_rtc_drv.c code and
mach-rtk119x/driver/dc2vo/fpga/include/mis_reg.h register definitions.

The base year 2014 was observed on all of Zidoo X9S, ProBox2 Ava and
Beelink Lake I.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-rtd119x.c [new file with mode: 0644]

index a76a26e..e0e58f3 100644 (file)
@@ -1765,6 +1765,14 @@ config RTC_DRV_CPCAP
           Say y here for CPCAP rtc found on some Motorola phones
           and tablets such as Droid 4.
 
+config RTC_DRV_RTD119X
+       bool "Realtek RTD129x RTC"
+       depends on ARCH_REALTEK || COMPILE_TEST
+       default ARCH_REALTEK
+       help
+         If you say yes here, you get support for the RTD1295 SoC
+         Real Time Clock.
+
 comment "HID Sensor RTC drivers"
 
 config RTC_DRV_HID_SENSOR_TIME
index d995d49..7230014 100644 (file)
@@ -131,6 +131,7 @@ obj-$(CONFIG_RTC_DRV_RP5C01)        += rtc-rp5c01.o
 obj-$(CONFIG_RTC_DRV_RS5C313)  += rtc-rs5c313.o
 obj-$(CONFIG_RTC_DRV_RS5C348)  += rtc-rs5c348.o
 obj-$(CONFIG_RTC_DRV_RS5C372)  += rtc-rs5c372.o
+obj-$(CONFIG_RTC_DRV_RTD119X)  += rtc-rtd119x.o
 obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o
 obj-$(CONFIG_RTC_DRV_RV8803)   += rtc-rv8803.o
 obj-$(CONFIG_RTC_DRV_RX4581)   += rtc-rx4581.o
diff --git a/drivers/rtc/rtc-rtd119x.c b/drivers/rtc/rtc-rtd119x.c
new file mode 100644 (file)
index 0000000..b233559
--- /dev/null
@@ -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);