// SPDX-License-Identifier: GPL-2.0-or-later /* * RTC driver for NXP LPC178x/18xx/43xx Real-Time Clock (RTC) * * Copyright (C) 2011 NXP Semiconductors * Copyright (C) 2015 Joachim Eastwood */ #include #include #include #include #include #include #include /* LPC24xx RTC register offsets and bits */ #define LPC24XX_ILR 0x00 #define LPC24XX_RTCCIF BIT(0) #define LPC24XX_RTCALF BIT(1) #define LPC24XX_CTC 0x04 #define LPC24XX_CCR 0x08 #define LPC24XX_CLKEN BIT(0) #define LPC178X_CCALEN BIT(4) #define LPC24XX_CIIR 0x0c #define LPC24XX_AMR 0x10 #define LPC24XX_ALARM_DISABLE 0xff #define LPC24XX_CTIME0 0x14 #define LPC24XX_CTIME1 0x18 #define LPC24XX_CTIME2 0x1c #define LPC24XX_SEC 0x20 #define LPC24XX_MIN 0x24 #define LPC24XX_HOUR 0x28 #define LPC24XX_DOM 0x2c #define LPC24XX_DOW 0x30 #define LPC24XX_DOY 0x34 #define LPC24XX_MONTH 0x38 #define LPC24XX_YEAR 0x3c #define LPC24XX_ALSEC 0x60 #define LPC24XX_ALMIN 0x64 #define LPC24XX_ALHOUR 0x68 #define LPC24XX_ALDOM 0x6c #define LPC24XX_ALDOW 0x70 #define LPC24XX_ALDOY 0x74 #define LPC24XX_ALMON 0x78 #define LPC24XX_ALYEAR 0x7c /* Macros to read fields in consolidated time (CT) registers */ #define CT0_SECS(x) (((x) >> 0) & 0x3f) #define CT0_MINS(x) (((x) >> 8) & 0x3f) #define CT0_HOURS(x) (((x) >> 16) & 0x1f) #define CT0_DOW(x) (((x) >> 24) & 0x07) #define CT1_DOM(x) (((x) >> 0) & 0x1f) #define CT1_MONTH(x) (((x) >> 8) & 0x0f) #define CT1_YEAR(x) (((x) >> 16) & 0xfff) #define CT2_DOY(x) (((x) >> 0) & 0xfff) #define rtc_readl(dev, reg) readl((dev)->rtc_base + (reg)) #define rtc_writel(dev, reg, val) writel((val), (dev)->rtc_base + (reg)) struct lpc24xx_rtc { void __iomem *rtc_base; struct rtc_device *rtc; struct clk *clk_rtc; struct clk *clk_reg; }; static int lpc24xx_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct lpc24xx_rtc *rtc = dev_get_drvdata(dev); /* Disable RTC during update */ rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN); rtc_writel(rtc, LPC24XX_SEC, tm->tm_sec); rtc_writel(rtc, LPC24XX_MIN, tm->tm_min); rtc_writel(rtc, LPC24XX_HOUR, tm->tm_hour); rtc_writel(rtc, LPC24XX_DOW, tm->tm_wday); rtc_writel(rtc, LPC24XX_DOM, tm->tm_mday); rtc_writel(rtc, LPC24XX_DOY, tm->tm_yday); rtc_writel(rtc, LPC24XX_MONTH, tm->tm_mon); rtc_writel(rtc, LPC24XX_YEAR, tm->tm_year); rtc_writel(rtc, LPC24XX_CCR, LPC24XX_CLKEN | LPC178X_CCALEN); return 0; } static int lpc24xx_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct lpc24xx_rtc *rtc = dev_get_drvdata(dev); u32 ct0, ct1, ct2; ct0 = rtc_readl(rtc, LPC24XX_CTIME0); ct1 = rtc_readl(rtc, LPC24XX_CTIME1); ct2 = rtc_readl(rtc, LPC24XX_CTIME2); tm->tm_sec = CT0_SECS(ct0); tm->tm_min = CT0_MINS(ct0); tm->tm_hour = CT0_HOURS(ct0); tm->tm_wday = CT0_DOW(ct0); tm->tm_mon = CT1_MONTH(ct1); tm->tm_mday = CT1_DOM(ct1); tm->tm_year = CT1_YEAR(ct1); tm->tm_yday = CT2_DOY(ct2); return 0; } static int lpc24xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct lpc24xx_rtc *rtc = dev_get_drvdata(dev); struct rtc_time *tm = &wkalrm->time; tm->tm_sec = rtc_readl(rtc, LPC24XX_ALSEC); tm->tm_min = rtc_readl(rtc, LPC24XX_ALMIN); tm->tm_hour = rtc_readl(rtc, LPC24XX_ALHOUR); tm->tm_mday = rtc_readl(rtc, LPC24XX_ALDOM); tm->tm_wday = rtc_readl(rtc, LPC24XX_ALDOW); tm->tm_yday = rtc_readl(rtc, LPC24XX_ALDOY); tm->tm_mon = rtc_readl(rtc, LPC24XX_ALMON); tm->tm_year = rtc_readl(rtc, LPC24XX_ALYEAR); wkalrm->enabled = rtc_readl(rtc, LPC24XX_AMR) == 0; wkalrm->pending = !!(rtc_readl(rtc, LPC24XX_ILR) & LPC24XX_RTCCIF); return rtc_valid_tm(&wkalrm->time); } static int lpc24xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct lpc24xx_rtc *rtc = dev_get_drvdata(dev); struct rtc_time *tm = &wkalrm->time; /* Disable alarm irq during update */ rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE); rtc_writel(rtc, LPC24XX_ALSEC, tm->tm_sec); rtc_writel(rtc, LPC24XX_ALMIN, tm->tm_min); rtc_writel(rtc, LPC24XX_ALHOUR, tm->tm_hour); rtc_writel(rtc, LPC24XX_ALDOM, tm->tm_mday); rtc_writel(rtc, LPC24XX_ALDOW, tm->tm_wday); rtc_writel(rtc, LPC24XX_ALDOY, tm->tm_yday); rtc_writel(rtc, LPC24XX_ALMON, tm->tm_mon); rtc_writel(rtc, LPC24XX_ALYEAR, tm->tm_year); if (wkalrm->enabled) rtc_writel(rtc, LPC24XX_AMR, 0); return 0; } static int lpc24xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) { struct lpc24xx_rtc *rtc = dev_get_drvdata(dev); if (enable) rtc_writel(rtc, LPC24XX_AMR, 0); else rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE); return 0; } static irqreturn_t lpc24xx_rtc_interrupt(int irq, void *data) { unsigned long events = RTC_IRQF; struct lpc24xx_rtc *rtc = data; u32 rtc_iir; /* Check interrupt cause */ rtc_iir = rtc_readl(rtc, LPC24XX_ILR); if (rtc_iir & LPC24XX_RTCALF) { events |= RTC_AF; rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE); } /* Clear interrupt status and report event */ rtc_writel(rtc, LPC24XX_ILR, rtc_iir); rtc_update_irq(rtc->rtc, 1, events); return IRQ_HANDLED; } static const struct rtc_class_ops lpc24xx_rtc_ops = { .read_time = lpc24xx_rtc_read_time, .set_time = lpc24xx_rtc_set_time, .read_alarm = lpc24xx_rtc_read_alarm, .set_alarm = lpc24xx_rtc_set_alarm, .alarm_irq_enable = lpc24xx_rtc_alarm_irq_enable, }; static int lpc24xx_rtc_probe(struct platform_device *pdev) { struct lpc24xx_rtc *rtc; int irq, ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; rtc->rtc_base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(rtc->rtc_base)) return PTR_ERR(rtc->rtc_base); irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; rtc->clk_rtc = devm_clk_get(&pdev->dev, "rtc"); if (IS_ERR(rtc->clk_rtc)) { dev_err(&pdev->dev, "error getting rtc clock\n"); return PTR_ERR(rtc->clk_rtc); } rtc->clk_reg = devm_clk_get(&pdev->dev, "reg"); if (IS_ERR(rtc->clk_reg)) { dev_err(&pdev->dev, "error getting reg clock\n"); return PTR_ERR(rtc->clk_reg); } ret = clk_prepare_enable(rtc->clk_rtc); if (ret) { dev_err(&pdev->dev, "unable to enable rtc clock\n"); return ret; } ret = clk_prepare_enable(rtc->clk_reg); if (ret) { dev_err(&pdev->dev, "unable to enable reg clock\n"); goto disable_rtc_clk; } platform_set_drvdata(pdev, rtc); /* Clear any pending interrupts */ rtc_writel(rtc, LPC24XX_ILR, LPC24XX_RTCCIF | LPC24XX_RTCALF); /* Enable RTC count */ rtc_writel(rtc, LPC24XX_CCR, LPC24XX_CLKEN | LPC178X_CCALEN); ret = devm_request_irq(&pdev->dev, irq, lpc24xx_rtc_interrupt, 0, pdev->name, rtc); if (ret < 0) { dev_warn(&pdev->dev, "can't request interrupt\n"); goto disable_clks; } rtc->rtc = devm_rtc_device_register(&pdev->dev, "lpc24xx-rtc", &lpc24xx_rtc_ops, THIS_MODULE); if (IS_ERR(rtc->rtc)) { dev_err(&pdev->dev, "can't register rtc device\n"); ret = PTR_ERR(rtc->rtc); goto disable_clks; } return 0; disable_clks: clk_disable_unprepare(rtc->clk_reg); disable_rtc_clk: clk_disable_unprepare(rtc->clk_rtc); return ret; } static void lpc24xx_rtc_remove(struct platform_device *pdev) { struct lpc24xx_rtc *rtc = platform_get_drvdata(pdev); /* Ensure all interrupt sources are masked */ rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE); rtc_writel(rtc, LPC24XX_CIIR, 0); rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN); clk_disable_unprepare(rtc->clk_rtc); clk_disable_unprepare(rtc->clk_reg); } static const struct of_device_id lpc24xx_rtc_match[] = { { .compatible = "nxp,lpc1788-rtc" }, { } }; MODULE_DEVICE_TABLE(of, lpc24xx_rtc_match); static struct platform_driver lpc24xx_rtc_driver = { .probe = lpc24xx_rtc_probe, .remove = lpc24xx_rtc_remove, .driver = { .name = "lpc24xx-rtc", .of_match_table = lpc24xx_rtc_match, }, }; module_platform_driver(lpc24xx_rtc_driver); MODULE_AUTHOR("Kevin Wells "); MODULE_DESCRIPTION("RTC driver for the LPC178x/18xx/408x/43xx SoCs"); MODULE_LICENSE("GPL");