diff options
Diffstat (limited to 'drivers/rtc/rtc-ma35d1.c')
| -rw-r--r-- | drivers/rtc/rtc-ma35d1.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ma35d1.c b/drivers/rtc/rtc-ma35d1.c new file mode 100644 index 000000000000..cfcfc28060f6 --- /dev/null +++ b/drivers/rtc/rtc-ma35d1.c @@ -0,0 +1,304 @@ +// 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; + } + + 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; + 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"); + + return 0; +} + +static int ma35d1_rtc_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct ma35_rtc *rtc = platform_get_drvdata(pdev); + + if (device_may_wakeup(&pdev->dev)) + enable_irq_wake(rtc->irq_num); + + return 0; +} + +static int ma35d1_rtc_resume(struct platform_device *pdev) +{ + struct ma35_rtc *rtc = platform_get_drvdata(pdev); + + if (device_may_wakeup(&pdev->dev)) + disable_irq_wake(rtc->irq_num); + + 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"); |