--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RTC driver for Nuvoton MA35D1
+ *
+ * Copyright (C) 2023 Nuvoton Technology Corp.
+ */
+
+#include <linux/bcd.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+/* MA35D1 RTC Control Registers */
+#define MA35_REG_RTC_INIT 0x00
+#define MA35_REG_RTC_SINFASTS 0x04
+#define MA35_REG_RTC_FREQADJ 0x08
+#define MA35_REG_RTC_TIME 0x0c
+#define MA35_REG_RTC_CAL 0x10
+#define MA35_REG_RTC_CLKFMT 0x14
+#define MA35_REG_RTC_WEEKDAY 0x18
+#define MA35_REG_RTC_TALM 0x1c
+#define MA35_REG_RTC_CALM 0x20
+#define MA35_REG_RTC_LEAPYEAR 0x24
+#define MA35_REG_RTC_INTEN 0x28
+#define MA35_REG_RTC_INTSTS 0x2c
+
+/* register MA35_REG_RTC_INIT */
+#define RTC_INIT_ACTIVE BIT(0)
+#define RTC_INIT_MAGIC_CODE 0xa5eb1357
+
+/* register MA35_REG_RTC_CLKFMT */
+#define RTC_CLKFMT_24HEN BIT(0)
+#define RTC_CLKFMT_DCOMPEN BIT(16)
+
+/* register MA35_REG_RTC_INTEN */
+#define RTC_INTEN_ALMIEN BIT(0)
+#define RTC_INTEN_UIEN BIT(1)
+#define RTC_INTEN_CLKFIEN BIT(24)
+#define RTC_INTEN_CLKSTIEN BIT(25)
+
+/* register MA35_REG_RTC_INTSTS */
+#define RTC_INTSTS_ALMIF BIT(0)
+#define RTC_INTSTS_UIF BIT(1)
+#define RTC_INTSTS_CLKFIF BIT(24)
+#define RTC_INTSTS_CLKSTIF BIT(25)
+
+#define RTC_INIT_TIMEOUT 250
+
+struct ma35_rtc {
+ int irq_num;
+ void __iomem *rtc_reg;
+ struct rtc_device *rtcdev;
+};
+
+static u32 rtc_reg_read(struct ma35_rtc *p, u32 offset)
+{
+ return __raw_readl(p->rtc_reg + offset);
+}
+
+static inline void rtc_reg_write(struct ma35_rtc *p, u32 offset, u32 value)
+{
+ __raw_writel(value, p->rtc_reg + offset);
+}
+
+static irqreturn_t ma35d1_rtc_interrupt(int irq, void *data)
+{
+ struct ma35_rtc *rtc = (struct ma35_rtc *)data;
+ unsigned long events = 0, rtc_irq;
+
+ rtc_irq = rtc_reg_read(rtc, MA35_REG_RTC_INTSTS);
+
+ if (rtc_irq & RTC_INTSTS_ALMIF) {
+ rtc_reg_write(rtc, MA35_REG_RTC_INTSTS, RTC_INTSTS_ALMIF);
+ events |= RTC_AF | RTC_IRQF;
+ }
+
+ if (rtc_irq & RTC_INTSTS_UIF) {
+ rtc_reg_write(rtc, MA35_REG_RTC_INTSTS, RTC_INTSTS_UIF);
+ events |= RTC_UF | RTC_IRQF;
+ }
+
+ rtc_update_irq(rtc->rtcdev, 1, events);
+
+ return IRQ_HANDLED;
+}
+
+static int ma35d1_rtc_init(struct ma35_rtc *rtc, u32 ms_timeout)
+{
+ const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
+
+ do {
+ if (rtc_reg_read(rtc, MA35_REG_RTC_INIT) & RTC_INIT_ACTIVE)
+ return 0;
+
+ rtc_reg_write(rtc, MA35_REG_RTC_INIT, RTC_INIT_MAGIC_CODE);
+
+ mdelay(1);
+
+ } while (time_before(jiffies, timeout));
+
+ return -ETIMEDOUT;
+}
+
+static int ma35d1_alarm_irq_enable(struct device *dev, u32 enabled)
+{
+ struct ma35_rtc *rtc = dev_get_drvdata(dev);
+ u32 reg_ien;
+
+ reg_ien = rtc_reg_read(rtc, MA35_REG_RTC_INTEN);
+
+ if (enabled)
+ rtc_reg_write(rtc, MA35_REG_RTC_INTEN, reg_ien | RTC_INTEN_ALMIEN);
+ else
+ rtc_reg_write(rtc, MA35_REG_RTC_INTEN, reg_ien & ~RTC_INTEN_ALMIEN);
+
+ return 0;
+}
+
+static int ma35d1_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ma35_rtc *rtc = dev_get_drvdata(dev);
+ u32 time, cal, wday;
+
+ do {
+ time = rtc_reg_read(rtc, MA35_REG_RTC_TIME);
+ cal = rtc_reg_read(rtc, MA35_REG_RTC_CAL);
+ wday = rtc_reg_read(rtc, MA35_REG_RTC_WEEKDAY);
+ } while (time != rtc_reg_read(rtc, MA35_REG_RTC_TIME) ||
+ cal != rtc_reg_read(rtc, MA35_REG_RTC_CAL));
+
+ tm->tm_mday = bcd2bin(cal >> 0);
+ tm->tm_wday = wday;
+ tm->tm_mon = bcd2bin(cal >> 8);
+ tm->tm_mon = tm->tm_mon - 1;
+ tm->tm_year = bcd2bin(cal >> 16) + 100;
+
+ tm->tm_sec = bcd2bin(time >> 0);
+ tm->tm_min = bcd2bin(time >> 8);
+ tm->tm_hour = bcd2bin(time >> 16);
+
+ return rtc_valid_tm(tm);
+}
+
+static int ma35d1_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ma35_rtc *rtc = dev_get_drvdata(dev);
+ u32 val;
+
+ val = bin2bcd(tm->tm_mday) << 0 | bin2bcd(tm->tm_mon + 1) << 8 |
+ bin2bcd(tm->tm_year - 100) << 16;
+ rtc_reg_write(rtc, MA35_REG_RTC_CAL, val);
+
+ val = bin2bcd(tm->tm_sec) << 0 | bin2bcd(tm->tm_min) << 8 |
+ bin2bcd(tm->tm_hour) << 16;
+ rtc_reg_write(rtc, MA35_REG_RTC_TIME, val);
+
+ val = tm->tm_wday;
+ rtc_reg_write(rtc, MA35_REG_RTC_WEEKDAY, val);
+
+ return 0;
+}
+
+static int ma35d1_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct ma35_rtc *rtc = dev_get_drvdata(dev);
+ u32 talm, calm;
+
+ talm = rtc_reg_read(rtc, MA35_REG_RTC_TALM);
+ calm = rtc_reg_read(rtc, MA35_REG_RTC_CALM);
+
+ alrm->time.tm_mday = bcd2bin(calm >> 0);
+ alrm->time.tm_mon = bcd2bin(calm >> 8);
+ alrm->time.tm_mon = alrm->time.tm_mon - 1;
+
+ alrm->time.tm_year = bcd2bin(calm >> 16) + 100;
+
+ alrm->time.tm_sec = bcd2bin(talm >> 0);
+ alrm->time.tm_min = bcd2bin(talm >> 8);
+ alrm->time.tm_hour = bcd2bin(talm >> 16);
+
+ return rtc_valid_tm(&alrm->time);
+}
+
+static int ma35d1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct ma35_rtc *rtc = dev_get_drvdata(dev);
+ unsigned long val;
+
+ val = bin2bcd(alrm->time.tm_mday) << 0 | bin2bcd(alrm->time.tm_mon + 1) << 8 |
+ bin2bcd(alrm->time.tm_year - 100) << 16;
+ rtc_reg_write(rtc, MA35_REG_RTC_CALM, val);
+
+ val = bin2bcd(alrm->time.tm_sec) << 0 | bin2bcd(alrm->time.tm_min) << 8 |
+ bin2bcd(alrm->time.tm_hour) << 16;
+ rtc_reg_write(rtc, MA35_REG_RTC_TALM, val);
+
+ ma35d1_alarm_irq_enable(dev, alrm->enabled);
+
+ return 0;
+}
+
+static const struct rtc_class_ops ma35d1_rtc_ops = {
+ .read_time = ma35d1_rtc_read_time,
+ .set_time = ma35d1_rtc_set_time,
+ .read_alarm = ma35d1_rtc_read_alarm,
+ .set_alarm = ma35d1_rtc_set_alarm,
+ .alarm_irq_enable = ma35d1_alarm_irq_enable,
+};
+
+static int ma35d1_rtc_probe(struct platform_device *pdev)
+{
+ struct ma35_rtc *rtc;
+ struct clk *clk;
+ u32 regval;
+ int ret;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ rtc->rtc_reg = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(rtc->rtc_reg))
+ return PTR_ERR(rtc->rtc_reg);
+
+ clk = of_clk_get(pdev->dev.of_node, 0);
+ if (IS_ERR(clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(clk), "failed to find rtc clock\n");
+
+ ret = clk_prepare_enable(clk);
+ if (ret)
+ return ret;
+
+ if (!(rtc_reg_read(rtc, MA35_REG_RTC_INIT) & RTC_INIT_ACTIVE)) {
+ ret = ma35d1_rtc_init(rtc, RTC_INIT_TIMEOUT);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "rtc init failed\n");
+ }
+
+ rtc->irq_num = platform_get_irq(pdev, 0);
+
+ ret = devm_request_irq(&pdev->dev, rtc->irq_num, ma35d1_rtc_interrupt,
+ IRQF_NO_SUSPEND, "ma35d1rtc", rtc);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to request rtc irq\n");
+
+ platform_set_drvdata(pdev, rtc);
+
+ device_init_wakeup(&pdev->dev, true);
+
+ rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc->rtcdev))
+ return PTR_ERR(rtc->rtcdev);
+
+ rtc->rtcdev->ops = &ma35d1_rtc_ops;
+ rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099;
+
+ ret = devm_rtc_register_device(rtc->rtcdev);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to register rtc device\n");
+
+ regval = rtc_reg_read(rtc, MA35_REG_RTC_INTEN);
+ regval |= RTC_INTEN_UIEN;
+ rtc_reg_write(rtc, MA35_REG_RTC_INTEN, regval);
+
+ return 0;
+}
+
+static int ma35d1_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct ma35_rtc *rtc = platform_get_drvdata(pdev);
+ u32 regval;
+
+ if (device_may_wakeup(&pdev->dev))
+ enable_irq_wake(rtc->irq_num);
+
+ regval = rtc_reg_read(rtc, MA35_REG_RTC_INTEN);
+ regval &= ~RTC_INTEN_UIEN;
+ rtc_reg_write(rtc, MA35_REG_RTC_INTEN, regval);
+
+ return 0;
+}
+
+static int ma35d1_rtc_resume(struct platform_device *pdev)
+{
+ struct ma35_rtc *rtc = platform_get_drvdata(pdev);
+ u32 regval;
+
+ if (device_may_wakeup(&pdev->dev))
+ disable_irq_wake(rtc->irq_num);
+
+ regval = rtc_reg_read(rtc, MA35_REG_RTC_INTEN);
+ regval |= RTC_INTEN_UIEN;
+ rtc_reg_write(rtc, MA35_REG_RTC_INTEN, regval);
+
+ return 0;
+}
+
+static const struct of_device_id ma35d1_rtc_of_match[] = {
+ { .compatible = "nuvoton,ma35d1-rtc", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ma35d1_rtc_of_match);
+
+static struct platform_driver ma35d1_rtc_driver = {
+ .suspend = ma35d1_rtc_suspend,
+ .resume = ma35d1_rtc_resume,
+ .probe = ma35d1_rtc_probe,
+ .driver = {
+ .name = "rtc-ma35d1",
+ .of_match_table = ma35d1_rtc_of_match,
+ },
+};
+
+module_platform_driver(ma35d1_rtc_driver);
+
+MODULE_AUTHOR("Ming-Jen Chen <mjchen@nuvoton.com>");
+MODULE_DESCRIPTION("MA35D1 RTC driver");
+MODULE_LICENSE("GPL");
projects / linux-block.git / commitdiff