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