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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * RTC driver for NXP LPC178x/18xx/43xx Real-Time Clock (RTC)4 *5 * Copyright (C) 2011 NXP Semiconductors6 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>7 */8 9#include <linux/clk.h>10#include <linux/io.h>11#include <linux/kernel.h>12#include <linux/mod_devicetable.h>13#include <linux/module.h>14#include <linux/platform_device.h>15#include <linux/rtc.h>16 17/* LPC24xx RTC register offsets and bits */18#define LPC24XX_ILR 0x0019#define LPC24XX_RTCCIF BIT(0)20#define LPC24XX_RTCALF BIT(1)21#define LPC24XX_CTC 0x0422#define LPC24XX_CCR 0x0823#define LPC24XX_CLKEN BIT(0)24#define LPC178X_CCALEN BIT(4)25#define LPC24XX_CIIR 0x0c26#define LPC24XX_AMR 0x1027#define LPC24XX_ALARM_DISABLE 0xff28#define LPC24XX_CTIME0 0x1429#define LPC24XX_CTIME1 0x1830#define LPC24XX_CTIME2 0x1c31#define LPC24XX_SEC 0x2032#define LPC24XX_MIN 0x2433#define LPC24XX_HOUR 0x2834#define LPC24XX_DOM 0x2c35#define LPC24XX_DOW 0x3036#define LPC24XX_DOY 0x3437#define LPC24XX_MONTH 0x3838#define LPC24XX_YEAR 0x3c39#define LPC24XX_ALSEC 0x6040#define LPC24XX_ALMIN 0x6441#define LPC24XX_ALHOUR 0x6842#define LPC24XX_ALDOM 0x6c43#define LPC24XX_ALDOW 0x7044#define LPC24XX_ALDOY 0x7445#define LPC24XX_ALMON 0x7846#define LPC24XX_ALYEAR 0x7c47 48/* Macros to read fields in consolidated time (CT) registers */49#define CT0_SECS(x) (((x) >> 0) & 0x3f)50#define CT0_MINS(x) (((x) >> 8) & 0x3f)51#define CT0_HOURS(x) (((x) >> 16) & 0x1f)52#define CT0_DOW(x) (((x) >> 24) & 0x07)53#define CT1_DOM(x) (((x) >> 0) & 0x1f)54#define CT1_MONTH(x) (((x) >> 8) & 0x0f)55#define CT1_YEAR(x) (((x) >> 16) & 0xfff)56#define CT2_DOY(x) (((x) >> 0) & 0xfff)57 58#define rtc_readl(dev, reg) readl((dev)->rtc_base + (reg))59#define rtc_writel(dev, reg, val) writel((val), (dev)->rtc_base + (reg))60 61struct lpc24xx_rtc {62 void __iomem *rtc_base;63 struct rtc_device *rtc;64 struct clk *clk_rtc;65 struct clk *clk_reg;66};67 68static int lpc24xx_rtc_set_time(struct device *dev, struct rtc_time *tm)69{70 struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);71 72 /* Disable RTC during update */73 rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN);74 75 rtc_writel(rtc, LPC24XX_SEC, tm->tm_sec);76 rtc_writel(rtc, LPC24XX_MIN, tm->tm_min);77 rtc_writel(rtc, LPC24XX_HOUR, tm->tm_hour);78 rtc_writel(rtc, LPC24XX_DOW, tm->tm_wday);79 rtc_writel(rtc, LPC24XX_DOM, tm->tm_mday);80 rtc_writel(rtc, LPC24XX_DOY, tm->tm_yday);81 rtc_writel(rtc, LPC24XX_MONTH, tm->tm_mon);82 rtc_writel(rtc, LPC24XX_YEAR, tm->tm_year);83 84 rtc_writel(rtc, LPC24XX_CCR, LPC24XX_CLKEN | LPC178X_CCALEN);85 86 return 0;87}88 89static int lpc24xx_rtc_read_time(struct device *dev, struct rtc_time *tm)90{91 struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);92 u32 ct0, ct1, ct2;93 94 ct0 = rtc_readl(rtc, LPC24XX_CTIME0);95 ct1 = rtc_readl(rtc, LPC24XX_CTIME1);96 ct2 = rtc_readl(rtc, LPC24XX_CTIME2);97 98 tm->tm_sec = CT0_SECS(ct0);99 tm->tm_min = CT0_MINS(ct0);100 tm->tm_hour = CT0_HOURS(ct0);101 tm->tm_wday = CT0_DOW(ct0);102 tm->tm_mon = CT1_MONTH(ct1);103 tm->tm_mday = CT1_DOM(ct1);104 tm->tm_year = CT1_YEAR(ct1);105 tm->tm_yday = CT2_DOY(ct2);106 107 return 0;108}109 110static int lpc24xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)111{112 struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);113 struct rtc_time *tm = &wkalrm->time;114 115 tm->tm_sec = rtc_readl(rtc, LPC24XX_ALSEC);116 tm->tm_min = rtc_readl(rtc, LPC24XX_ALMIN);117 tm->tm_hour = rtc_readl(rtc, LPC24XX_ALHOUR);118 tm->tm_mday = rtc_readl(rtc, LPC24XX_ALDOM);119 tm->tm_wday = rtc_readl(rtc, LPC24XX_ALDOW);120 tm->tm_yday = rtc_readl(rtc, LPC24XX_ALDOY);121 tm->tm_mon = rtc_readl(rtc, LPC24XX_ALMON);122 tm->tm_year = rtc_readl(rtc, LPC24XX_ALYEAR);123 124 wkalrm->enabled = rtc_readl(rtc, LPC24XX_AMR) == 0;125 wkalrm->pending = !!(rtc_readl(rtc, LPC24XX_ILR) & LPC24XX_RTCCIF);126 127 return rtc_valid_tm(&wkalrm->time);128}129 130static int lpc24xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)131{132 struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);133 struct rtc_time *tm = &wkalrm->time;134 135 /* Disable alarm irq during update */136 rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);137 138 rtc_writel(rtc, LPC24XX_ALSEC, tm->tm_sec);139 rtc_writel(rtc, LPC24XX_ALMIN, tm->tm_min);140 rtc_writel(rtc, LPC24XX_ALHOUR, tm->tm_hour);141 rtc_writel(rtc, LPC24XX_ALDOM, tm->tm_mday);142 rtc_writel(rtc, LPC24XX_ALDOW, tm->tm_wday);143 rtc_writel(rtc, LPC24XX_ALDOY, tm->tm_yday);144 rtc_writel(rtc, LPC24XX_ALMON, tm->tm_mon);145 rtc_writel(rtc, LPC24XX_ALYEAR, tm->tm_year);146 147 if (wkalrm->enabled)148 rtc_writel(rtc, LPC24XX_AMR, 0);149 150 return 0;151}152 153static int lpc24xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)154{155 struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);156 157 if (enable)158 rtc_writel(rtc, LPC24XX_AMR, 0);159 else160 rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);161 162 return 0;163}164 165static irqreturn_t lpc24xx_rtc_interrupt(int irq, void *data)166{167 unsigned long events = RTC_IRQF;168 struct lpc24xx_rtc *rtc = data;169 u32 rtc_iir;170 171 /* Check interrupt cause */172 rtc_iir = rtc_readl(rtc, LPC24XX_ILR);173 if (rtc_iir & LPC24XX_RTCALF) {174 events |= RTC_AF;175 rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);176 }177 178 /* Clear interrupt status and report event */179 rtc_writel(rtc, LPC24XX_ILR, rtc_iir);180 rtc_update_irq(rtc->rtc, 1, events);181 182 return IRQ_HANDLED;183}184 185static const struct rtc_class_ops lpc24xx_rtc_ops = {186 .read_time = lpc24xx_rtc_read_time,187 .set_time = lpc24xx_rtc_set_time,188 .read_alarm = lpc24xx_rtc_read_alarm,189 .set_alarm = lpc24xx_rtc_set_alarm,190 .alarm_irq_enable = lpc24xx_rtc_alarm_irq_enable,191};192 193static int lpc24xx_rtc_probe(struct platform_device *pdev)194{195 struct lpc24xx_rtc *rtc;196 int irq, ret;197 198 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);199 if (!rtc)200 return -ENOMEM;201 202 rtc->rtc_base = devm_platform_ioremap_resource(pdev, 0);203 if (IS_ERR(rtc->rtc_base))204 return PTR_ERR(rtc->rtc_base);205 206 irq = platform_get_irq(pdev, 0);207 if (irq < 0)208 return irq;209 210 rtc->clk_rtc = devm_clk_get(&pdev->dev, "rtc");211 if (IS_ERR(rtc->clk_rtc)) {212 dev_err(&pdev->dev, "error getting rtc clock\n");213 return PTR_ERR(rtc->clk_rtc);214 }215 216 rtc->clk_reg = devm_clk_get(&pdev->dev, "reg");217 if (IS_ERR(rtc->clk_reg)) {218 dev_err(&pdev->dev, "error getting reg clock\n");219 return PTR_ERR(rtc->clk_reg);220 }221 222 ret = clk_prepare_enable(rtc->clk_rtc);223 if (ret) {224 dev_err(&pdev->dev, "unable to enable rtc clock\n");225 return ret;226 }227 228 ret = clk_prepare_enable(rtc->clk_reg);229 if (ret) {230 dev_err(&pdev->dev, "unable to enable reg clock\n");231 goto disable_rtc_clk;232 }233 234 platform_set_drvdata(pdev, rtc);235 236 /* Clear any pending interrupts */237 rtc_writel(rtc, LPC24XX_ILR, LPC24XX_RTCCIF | LPC24XX_RTCALF);238 239 /* Enable RTC count */240 rtc_writel(rtc, LPC24XX_CCR, LPC24XX_CLKEN | LPC178X_CCALEN);241 242 ret = devm_request_irq(&pdev->dev, irq, lpc24xx_rtc_interrupt, 0,243 pdev->name, rtc);244 if (ret < 0) {245 dev_warn(&pdev->dev, "can't request interrupt\n");246 goto disable_clks;247 }248 249 rtc->rtc = devm_rtc_device_register(&pdev->dev, "lpc24xx-rtc",250 &lpc24xx_rtc_ops, THIS_MODULE);251 if (IS_ERR(rtc->rtc)) {252 dev_err(&pdev->dev, "can't register rtc device\n");253 ret = PTR_ERR(rtc->rtc);254 goto disable_clks;255 }256 257 return 0;258 259disable_clks:260 clk_disable_unprepare(rtc->clk_reg);261disable_rtc_clk:262 clk_disable_unprepare(rtc->clk_rtc);263 return ret;264}265 266static void lpc24xx_rtc_remove(struct platform_device *pdev)267{268 struct lpc24xx_rtc *rtc = platform_get_drvdata(pdev);269 270 /* Ensure all interrupt sources are masked */271 rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);272 rtc_writel(rtc, LPC24XX_CIIR, 0);273 274 rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN);275 276 clk_disable_unprepare(rtc->clk_rtc);277 clk_disable_unprepare(rtc->clk_reg);278}279 280static const struct of_device_id lpc24xx_rtc_match[] = {281 { .compatible = "nxp,lpc1788-rtc" },282 { }283};284MODULE_DEVICE_TABLE(of, lpc24xx_rtc_match);285 286static struct platform_driver lpc24xx_rtc_driver = {287 .probe = lpc24xx_rtc_probe,288 .remove_new = lpc24xx_rtc_remove,289 .driver = {290 .name = "lpc24xx-rtc",291 .of_match_table = lpc24xx_rtc_match,292 },293};294module_platform_driver(lpc24xx_rtc_driver);295 296MODULE_AUTHOR("Kevin Wells <wellsk40@gmail.com>");297MODULE_DESCRIPTION("RTC driver for the LPC178x/18xx/408x/43xx SoCs");298MODULE_LICENSE("GPL");299