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414 lines
10 KiB
414 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright 2019 Cadence |
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* |
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* Authors: |
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* Jan Kotas <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/platform_device.h> |
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#include <linux/of.h> |
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#include <linux/io.h> |
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#include <linux/rtc.h> |
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#include <linux/clk.h> |
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#include <linux/bcd.h> |
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#include <linux/bitfield.h> |
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#include <linux/interrupt.h> |
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#include <linux/pm_wakeirq.h> |
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/* Registers */ |
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#define CDNS_RTC_CTLR 0x00 |
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#define CDNS_RTC_HMR 0x04 |
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#define CDNS_RTC_TIMR 0x08 |
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#define CDNS_RTC_CALR 0x0C |
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#define CDNS_RTC_TIMAR 0x10 |
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#define CDNS_RTC_CALAR 0x14 |
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#define CDNS_RTC_AENR 0x18 |
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#define CDNS_RTC_EFLR 0x1C |
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#define CDNS_RTC_IENR 0x20 |
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#define CDNS_RTC_IDISR 0x24 |
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#define CDNS_RTC_IMSKR 0x28 |
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#define CDNS_RTC_STSR 0x2C |
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#define CDNS_RTC_KRTCR 0x30 |
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/* Control */ |
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#define CDNS_RTC_CTLR_TIME BIT(0) |
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#define CDNS_RTC_CTLR_CAL BIT(1) |
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#define CDNS_RTC_CTLR_TIME_CAL (CDNS_RTC_CTLR_TIME | CDNS_RTC_CTLR_CAL) |
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/* Status */ |
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#define CDNS_RTC_STSR_VT BIT(0) |
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#define CDNS_RTC_STSR_VC BIT(1) |
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#define CDNS_RTC_STSR_VTA BIT(2) |
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#define CDNS_RTC_STSR_VCA BIT(3) |
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#define CDNS_RTC_STSR_VT_VC (CDNS_RTC_STSR_VT | CDNS_RTC_STSR_VC) |
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#define CDNS_RTC_STSR_VTA_VCA (CDNS_RTC_STSR_VTA | CDNS_RTC_STSR_VCA) |
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/* Keep RTC */ |
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#define CDNS_RTC_KRTCR_KRTC BIT(0) |
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/* Alarm, Event, Interrupt */ |
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#define CDNS_RTC_AEI_HOS BIT(0) |
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#define CDNS_RTC_AEI_SEC BIT(1) |
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#define CDNS_RTC_AEI_MIN BIT(2) |
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#define CDNS_RTC_AEI_HOUR BIT(3) |
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#define CDNS_RTC_AEI_DATE BIT(4) |
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#define CDNS_RTC_AEI_MNTH BIT(5) |
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#define CDNS_RTC_AEI_ALRM BIT(6) |
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/* Time */ |
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#define CDNS_RTC_TIME_H GENMASK(7, 0) |
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#define CDNS_RTC_TIME_S GENMASK(14, 8) |
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#define CDNS_RTC_TIME_M GENMASK(22, 16) |
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#define CDNS_RTC_TIME_HR GENMASK(29, 24) |
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#define CDNS_RTC_TIME_PM BIT(30) |
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#define CDNS_RTC_TIME_CH BIT(31) |
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/* Calendar */ |
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#define CDNS_RTC_CAL_DAY GENMASK(2, 0) |
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#define CDNS_RTC_CAL_M GENMASK(7, 3) |
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#define CDNS_RTC_CAL_D GENMASK(13, 8) |
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#define CDNS_RTC_CAL_Y GENMASK(23, 16) |
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#define CDNS_RTC_CAL_C GENMASK(29, 24) |
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#define CDNS_RTC_CAL_CH BIT(31) |
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#define CDNS_RTC_MAX_REGS_TRIES 3 |
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struct cdns_rtc { |
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struct rtc_device *rtc_dev; |
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struct clk *pclk; |
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struct clk *ref_clk; |
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void __iomem *regs; |
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int irq; |
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}; |
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static void cdns_rtc_set_enabled(struct cdns_rtc *crtc, bool enabled) |
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{ |
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u32 reg = enabled ? 0x0 : CDNS_RTC_CTLR_TIME_CAL; |
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writel(reg, crtc->regs + CDNS_RTC_CTLR); |
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} |
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static bool cdns_rtc_get_enabled(struct cdns_rtc *crtc) |
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{ |
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return !(readl(crtc->regs + CDNS_RTC_CTLR) & CDNS_RTC_CTLR_TIME_CAL); |
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} |
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static irqreturn_t cdns_rtc_irq_handler(int irq, void *id) |
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{ |
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struct device *dev = id; |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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/* Reading the register clears it */ |
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if (!(readl(crtc->regs + CDNS_RTC_EFLR) & CDNS_RTC_AEI_ALRM)) |
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return IRQ_NONE; |
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rtc_update_irq(crtc->rtc_dev, 1, RTC_IRQF | RTC_AF); |
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return IRQ_HANDLED; |
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} |
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static u32 cdns_rtc_time2reg(struct rtc_time *tm) |
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{ |
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return FIELD_PREP(CDNS_RTC_TIME_S, bin2bcd(tm->tm_sec)) |
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| FIELD_PREP(CDNS_RTC_TIME_M, bin2bcd(tm->tm_min)) |
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| FIELD_PREP(CDNS_RTC_TIME_HR, bin2bcd(tm->tm_hour)); |
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} |
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static void cdns_rtc_reg2time(u32 reg, struct rtc_time *tm) |
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{ |
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tm->tm_sec = bcd2bin(FIELD_GET(CDNS_RTC_TIME_S, reg)); |
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tm->tm_min = bcd2bin(FIELD_GET(CDNS_RTC_TIME_M, reg)); |
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tm->tm_hour = bcd2bin(FIELD_GET(CDNS_RTC_TIME_HR, reg)); |
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} |
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static int cdns_rtc_read_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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u32 reg; |
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/* If the RTC is disabled, assume the values are invalid */ |
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if (!cdns_rtc_get_enabled(crtc)) |
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return -EINVAL; |
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cdns_rtc_set_enabled(crtc, false); |
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reg = readl(crtc->regs + CDNS_RTC_TIMR); |
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cdns_rtc_reg2time(reg, tm); |
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reg = readl(crtc->regs + CDNS_RTC_CALR); |
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tm->tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg)); |
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tm->tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1; |
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tm->tm_year = bcd2bin(FIELD_GET(CDNS_RTC_CAL_Y, reg)) |
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+ bcd2bin(FIELD_GET(CDNS_RTC_CAL_C, reg)) * 100 - 1900; |
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tm->tm_wday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_DAY, reg)) - 1; |
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cdns_rtc_set_enabled(crtc, true); |
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return 0; |
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} |
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static int cdns_rtc_set_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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u32 timr, calr, stsr; |
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int ret = -EIO; |
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int year = tm->tm_year + 1900; |
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int tries; |
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cdns_rtc_set_enabled(crtc, false); |
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timr = cdns_rtc_time2reg(tm); |
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calr = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(tm->tm_mday)) |
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| FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(tm->tm_mon + 1)) |
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| FIELD_PREP(CDNS_RTC_CAL_Y, bin2bcd(year % 100)) |
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| FIELD_PREP(CDNS_RTC_CAL_C, bin2bcd(year / 100)) |
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| FIELD_PREP(CDNS_RTC_CAL_DAY, tm->tm_wday + 1); |
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/* Update registers, check valid flags */ |
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for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) { |
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writel(timr, crtc->regs + CDNS_RTC_TIMR); |
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writel(calr, crtc->regs + CDNS_RTC_CALR); |
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stsr = readl(crtc->regs + CDNS_RTC_STSR); |
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if ((stsr & CDNS_RTC_STSR_VT_VC) == CDNS_RTC_STSR_VT_VC) { |
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ret = 0; |
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break; |
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} |
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} |
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cdns_rtc_set_enabled(crtc, true); |
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return ret; |
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} |
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static int cdns_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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if (enabled) { |
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writel((CDNS_RTC_AEI_SEC | CDNS_RTC_AEI_MIN | CDNS_RTC_AEI_HOUR |
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| CDNS_RTC_AEI_DATE | CDNS_RTC_AEI_MNTH), |
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crtc->regs + CDNS_RTC_AENR); |
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writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IENR); |
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} else { |
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writel(0, crtc->regs + CDNS_RTC_AENR); |
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writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IDISR); |
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} |
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return 0; |
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} |
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static int cdns_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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u32 reg; |
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reg = readl(crtc->regs + CDNS_RTC_TIMAR); |
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cdns_rtc_reg2time(reg, &alarm->time); |
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reg = readl(crtc->regs + CDNS_RTC_CALAR); |
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alarm->time.tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg)); |
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alarm->time.tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1; |
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return 0; |
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} |
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static int cdns_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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int ret = -EIO; |
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int tries; |
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u32 timar, calar, stsr; |
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cdns_rtc_alarm_irq_enable(dev, 0); |
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timar = cdns_rtc_time2reg(&alarm->time); |
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calar = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(alarm->time.tm_mday)) |
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| FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(alarm->time.tm_mon + 1)); |
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/* Update registers, check valid alarm flags */ |
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for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) { |
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writel(timar, crtc->regs + CDNS_RTC_TIMAR); |
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writel(calar, crtc->regs + CDNS_RTC_CALAR); |
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stsr = readl(crtc->regs + CDNS_RTC_STSR); |
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if ((stsr & CDNS_RTC_STSR_VTA_VCA) == CDNS_RTC_STSR_VTA_VCA) { |
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ret = 0; |
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break; |
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} |
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} |
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if (!ret) |
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cdns_rtc_alarm_irq_enable(dev, alarm->enabled); |
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return ret; |
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} |
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static const struct rtc_class_ops cdns_rtc_ops = { |
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.read_time = cdns_rtc_read_time, |
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.set_time = cdns_rtc_set_time, |
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.read_alarm = cdns_rtc_read_alarm, |
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.set_alarm = cdns_rtc_set_alarm, |
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.alarm_irq_enable = cdns_rtc_alarm_irq_enable, |
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}; |
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static int cdns_rtc_probe(struct platform_device *pdev) |
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{ |
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struct cdns_rtc *crtc; |
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int ret; |
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unsigned long ref_clk_freq; |
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crtc = devm_kzalloc(&pdev->dev, sizeof(*crtc), GFP_KERNEL); |
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if (!crtc) |
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return -ENOMEM; |
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crtc->regs = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(crtc->regs)) |
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return PTR_ERR(crtc->regs); |
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crtc->irq = platform_get_irq(pdev, 0); |
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if (crtc->irq < 0) |
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return -EINVAL; |
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crtc->pclk = devm_clk_get(&pdev->dev, "pclk"); |
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if (IS_ERR(crtc->pclk)) { |
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ret = PTR_ERR(crtc->pclk); |
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dev_err(&pdev->dev, |
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"Failed to retrieve the peripheral clock, %d\n", ret); |
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return ret; |
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} |
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crtc->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); |
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if (IS_ERR(crtc->ref_clk)) { |
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ret = PTR_ERR(crtc->ref_clk); |
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dev_err(&pdev->dev, |
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"Failed to retrieve the reference clock, %d\n", ret); |
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return ret; |
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} |
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crtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); |
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if (IS_ERR(crtc->rtc_dev)) |
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return PTR_ERR(crtc->rtc_dev); |
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platform_set_drvdata(pdev, crtc); |
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ret = clk_prepare_enable(crtc->pclk); |
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if (ret) { |
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dev_err(&pdev->dev, |
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"Failed to enable the peripheral clock, %d\n", ret); |
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return ret; |
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} |
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ret = clk_prepare_enable(crtc->ref_clk); |
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if (ret) { |
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dev_err(&pdev->dev, |
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"Failed to enable the reference clock, %d\n", ret); |
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goto err_disable_pclk; |
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} |
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ref_clk_freq = clk_get_rate(crtc->ref_clk); |
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if ((ref_clk_freq != 1) && (ref_clk_freq != 100)) { |
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dev_err(&pdev->dev, |
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"Invalid reference clock frequency %lu Hz.\n", |
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ref_clk_freq); |
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ret = -EINVAL; |
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goto err_disable_ref_clk; |
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} |
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ret = devm_request_irq(&pdev->dev, crtc->irq, |
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cdns_rtc_irq_handler, 0, |
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dev_name(&pdev->dev), &pdev->dev); |
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if (ret) { |
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dev_err(&pdev->dev, |
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"Failed to request interrupt for the device, %d\n", |
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ret); |
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goto err_disable_ref_clk; |
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} |
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/* The RTC supports 01.01.1900 - 31.12.2999 */ |
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crtc->rtc_dev->range_min = mktime64(1900, 1, 1, 0, 0, 0); |
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crtc->rtc_dev->range_max = mktime64(2999, 12, 31, 23, 59, 59); |
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crtc->rtc_dev->ops = &cdns_rtc_ops; |
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device_init_wakeup(&pdev->dev, true); |
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/* Always use 24-hour mode and keep the RTC values */ |
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writel(0, crtc->regs + CDNS_RTC_HMR); |
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writel(CDNS_RTC_KRTCR_KRTC, crtc->regs + CDNS_RTC_KRTCR); |
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ret = devm_rtc_register_device(crtc->rtc_dev); |
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if (ret) |
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goto err_disable_wakeup; |
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return 0; |
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err_disable_wakeup: |
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device_init_wakeup(&pdev->dev, false); |
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err_disable_ref_clk: |
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clk_disable_unprepare(crtc->ref_clk); |
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err_disable_pclk: |
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clk_disable_unprepare(crtc->pclk); |
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return ret; |
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} |
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static int cdns_rtc_remove(struct platform_device *pdev) |
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{ |
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struct cdns_rtc *crtc = platform_get_drvdata(pdev); |
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cdns_rtc_alarm_irq_enable(&pdev->dev, 0); |
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device_init_wakeup(&pdev->dev, 0); |
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clk_disable_unprepare(crtc->pclk); |
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clk_disable_unprepare(crtc->ref_clk); |
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return 0; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int cdns_rtc_suspend(struct device *dev) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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if (device_may_wakeup(dev)) |
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enable_irq_wake(crtc->irq); |
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return 0; |
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} |
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static int cdns_rtc_resume(struct device *dev) |
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{ |
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struct cdns_rtc *crtc = dev_get_drvdata(dev); |
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if (device_may_wakeup(dev)) |
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disable_irq_wake(crtc->irq); |
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return 0; |
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} |
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#endif |
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static SIMPLE_DEV_PM_OPS(cdns_rtc_pm_ops, cdns_rtc_suspend, cdns_rtc_resume); |
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static const struct of_device_id cdns_rtc_of_match[] = { |
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{ .compatible = "cdns,rtc-r109v3" }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, cdns_rtc_of_match); |
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static struct platform_driver cdns_rtc_driver = { |
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.driver = { |
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.name = "cdns-rtc", |
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.of_match_table = cdns_rtc_of_match, |
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.pm = &cdns_rtc_pm_ops, |
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}, |
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.probe = cdns_rtc_probe, |
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.remove = cdns_rtc_remove, |
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}; |
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module_platform_driver(cdns_rtc_driver); |
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MODULE_AUTHOR("Jan Kotas <[email protected]>"); |
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MODULE_DESCRIPTION("Cadence RTC driver"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:cdns-rtc");
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