424 lines
11 KiB
C
424 lines
11 KiB
C
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// 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 <jank@cadence.com>
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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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struct resource *res;
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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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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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crtc->regs = devm_ioremap_resource(&pdev->dev, res);
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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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ret = PTR_ERR(crtc->rtc_dev);
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dev_err(&pdev->dev,
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"Failed to allocate the RTC device, %d\n", ret);
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return ret;
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}
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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;
|
||
|
|
device_init_wakeup(&pdev->dev, true);
|
||
|
|
|
||
|
|
/* Always use 24-hour mode and keep the RTC values */
|
||
|
|
writel(0, crtc->regs + CDNS_RTC_HMR);
|
||
|
|
writel(CDNS_RTC_KRTCR_KRTC, crtc->regs + CDNS_RTC_KRTCR);
|
||
|
|
|
||
|
|
ret = rtc_register_device(crtc->rtc_dev);
|
||
|
|
if (ret) {
|
||
|
|
dev_err(&pdev->dev,
|
||
|
|
"Failed to register the RTC device, %d\n", ret);
|
||
|
|
goto err_disable_wakeup;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
err_disable_wakeup:
|
||
|
|
device_init_wakeup(&pdev->dev, false);
|
||
|
|
|
||
|
|
err_disable_ref_clk:
|
||
|
|
clk_disable_unprepare(crtc->ref_clk);
|
||
|
|
|
||
|
|
err_disable_pclk:
|
||
|
|
clk_disable_unprepare(crtc->pclk);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int cdns_rtc_remove(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
struct cdns_rtc *crtc = platform_get_drvdata(pdev);
|
||
|
|
|
||
|
|
cdns_rtc_alarm_irq_enable(&pdev->dev, 0);
|
||
|
|
device_init_wakeup(&pdev->dev, 0);
|
||
|
|
|
||
|
|
clk_disable_unprepare(crtc->pclk);
|
||
|
|
clk_disable_unprepare(crtc->ref_clk);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef CONFIG_PM_SLEEP
|
||
|
|
static int cdns_rtc_suspend(struct device *dev)
|
||
|
|
{
|
||
|
|
struct cdns_rtc *crtc = dev_get_drvdata(dev);
|
||
|
|
|
||
|
|
if (device_may_wakeup(dev))
|
||
|
|
enable_irq_wake(crtc->irq);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int cdns_rtc_resume(struct device *dev)
|
||
|
|
{
|
||
|
|
struct cdns_rtc *crtc = dev_get_drvdata(dev);
|
||
|
|
|
||
|
|
if (device_may_wakeup(dev))
|
||
|
|
disable_irq_wake(crtc->irq);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static SIMPLE_DEV_PM_OPS(cdns_rtc_pm_ops, cdns_rtc_suspend, cdns_rtc_resume);
|
||
|
|
|
||
|
|
static const struct of_device_id cdns_rtc_of_match[] = {
|
||
|
|
{ .compatible = "cdns,rtc-r109v3" },
|
||
|
|
{ },
|
||
|
|
};
|
||
|
|
MODULE_DEVICE_TABLE(of, cdns_rtc_of_match);
|
||
|
|
|
||
|
|
static struct platform_driver cdns_rtc_driver = {
|
||
|
|
.driver = {
|
||
|
|
.name = "cdns-rtc",
|
||
|
|
.of_match_table = cdns_rtc_of_match,
|
||
|
|
.pm = &cdns_rtc_pm_ops,
|
||
|
|
},
|
||
|
|
.probe = cdns_rtc_probe,
|
||
|
|
.remove = cdns_rtc_remove,
|
||
|
|
};
|
||
|
|
module_platform_driver(cdns_rtc_driver);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
|
||
|
|
MODULE_DESCRIPTION("Cadence RTC driver");
|
||
|
|
MODULE_LICENSE("GPL v2");
|
||
|
|
MODULE_ALIAS("platform:cdns-rtc");
|