| // 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 <manabian@gmail.com> |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/io.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/platform_device.h> |
| #include <linux/rtc.h> |
| |
| /* 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_new = lpc24xx_rtc_remove, |
| .driver = { |
| .name = "lpc24xx-rtc", |
| .of_match_table = lpc24xx_rtc_match, |
| }, |
| }; |
| module_platform_driver(lpc24xx_rtc_driver); |
| |
| MODULE_AUTHOR("Kevin Wells <wellsk40@gmail.com>"); |
| MODULE_DESCRIPTION("RTC driver for the LPC178x/18xx/408x/43xx SoCs"); |
| MODULE_LICENSE("GPL"); |