// SPDX-License-Identifier: GPL-2.0-or-later /* * DaVinci Power Management and Real Time Clock Driver for TI platforms * * Copyright (C) 2009 Texas Instruments, Inc * * Author: Miguel Aguilar <miguel.aguilar@ridgerun.com> */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/module.h> #include <linux/ioport.h> #include <linux/delay.h> #include <linux/spinlock.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/platform_device.h> #include <linux/io.h> #include <linux/slab.h> /* * The DaVinci RTC is a simple RTC with the following * Sec: 0 - 59 : BCD count * Min: 0 - 59 : BCD count * Hour: 0 - 23 : BCD count * Day: 0 - 0x7FFF(32767) : Binary count ( Over 89 years ) */ /* PRTC interface registers */ #define DAVINCI_PRTCIF_PID 0x00 #define PRTCIF_CTLR 0x04 #define PRTCIF_LDATA 0x08 #define PRTCIF_UDATA 0x0C #define PRTCIF_INTEN 0x10 #define PRTCIF_INTFLG 0x14 /* PRTCIF_CTLR bit fields */ #define PRTCIF_CTLR_BUSY BIT(31) #define PRTCIF_CTLR_SIZE BIT(25) #define PRTCIF_CTLR_DIR BIT(24) #define PRTCIF_CTLR_BENU_MSB BIT(23) #define PRTCIF_CTLR_BENU_3RD_BYTE BIT(22) #define PRTCIF_CTLR_BENU_2ND_BYTE BIT(21) #define PRTCIF_CTLR_BENU_LSB BIT(20) #define PRTCIF_CTLR_BENU_MASK (0x00F00000) #define PRTCIF_CTLR_BENL_MSB BIT(19) #define PRTCIF_CTLR_BENL_3RD_BYTE BIT(18) #define PRTCIF_CTLR_BENL_2ND_BYTE BIT(17) #define PRTCIF_CTLR_BENL_LSB BIT(16) #define PRTCIF_CTLR_BENL_MASK (0x000F0000) /* PRTCIF_INTEN bit fields */ #define PRTCIF_INTEN_RTCSS BIT(1) #define PRTCIF_INTEN_RTCIF BIT(0) #define PRTCIF_INTEN_MASK (PRTCIF_INTEN_RTCSS \ | PRTCIF_INTEN_RTCIF) /* PRTCIF_INTFLG bit fields */ #define PRTCIF_INTFLG_RTCSS BIT(1) #define PRTCIF_INTFLG_RTCIF BIT(0) #define PRTCIF_INTFLG_MASK (PRTCIF_INTFLG_RTCSS \ | PRTCIF_INTFLG_RTCIF) /* PRTC subsystem registers */ #define PRTCSS_RTC_INTC_EXTENA1 (0x0C) #define PRTCSS_RTC_CTRL (0x10) #define PRTCSS_RTC_WDT (0x11) #define PRTCSS_RTC_TMR0 (0x12) #define PRTCSS_RTC_TMR1 (0x13) #define PRTCSS_RTC_CCTRL (0x14) #define PRTCSS_RTC_SEC (0x15) #define PRTCSS_RTC_MIN (0x16) #define PRTCSS_RTC_HOUR (0x17) #define PRTCSS_RTC_DAY0 (0x18) #define PRTCSS_RTC_DAY1 (0x19) #define PRTCSS_RTC_AMIN (0x1A) #define PRTCSS_RTC_AHOUR (0x1B) #define PRTCSS_RTC_ADAY0 (0x1C) #define PRTCSS_RTC_ADAY1 (0x1D) #define PRTCSS_RTC_CLKC_CNT (0x20) /* PRTCSS_RTC_INTC_EXTENA1 */ #define PRTCSS_RTC_INTC_EXTENA1_MASK (0x07) /* PRTCSS_RTC_CTRL bit fields */ #define PRTCSS_RTC_CTRL_WDTBUS BIT(7) #define PRTCSS_RTC_CTRL_WEN BIT(6) #define PRTCSS_RTC_CTRL_WDRT BIT(5) #define PRTCSS_RTC_CTRL_WDTFLG BIT(4) #define PRTCSS_RTC_CTRL_TE BIT(3) #define PRTCSS_RTC_CTRL_TIEN BIT(2) #define PRTCSS_RTC_CTRL_TMRFLG BIT(1) #define PRTCSS_RTC_CTRL_TMMD BIT(0) /* PRTCSS_RTC_CCTRL bit fields */ #define PRTCSS_RTC_CCTRL_CALBUSY BIT(7) #define PRTCSS_RTC_CCTRL_DAEN BIT(5) #define PRTCSS_RTC_CCTRL_HAEN BIT(4) #define PRTCSS_RTC_CCTRL_MAEN BIT(3) #define PRTCSS_RTC_CCTRL_ALMFLG BIT(2) #define PRTCSS_RTC_CCTRL_AIEN BIT(1) #define PRTCSS_RTC_CCTRL_CAEN BIT(0) static DEFINE_SPINLOCK(davinci_rtc_lock); struct davinci_rtc { struct rtc_device *rtc; void __iomem *base; int irq; }; static inline void rtcif_write(struct davinci_rtc *davinci_rtc, u32 val, u32 addr) { writel(val, davinci_rtc->base + addr); } static inline u32 rtcif_read(struct davinci_rtc *davinci_rtc, u32 addr) { return readl(davinci_rtc->base + addr); } static inline void rtcif_wait(struct davinci_rtc *davinci_rtc) { while (rtcif_read(davinci_rtc, PRTCIF_CTLR) & PRTCIF_CTLR_BUSY) cpu_relax(); } static inline void rtcss_write(struct davinci_rtc *davinci_rtc, unsigned long val, u8 addr) { rtcif_wait(davinci_rtc); rtcif_write(davinci_rtc, PRTCIF_CTLR_BENL_LSB | addr, PRTCIF_CTLR); rtcif_write(davinci_rtc, val, PRTCIF_LDATA); rtcif_wait(davinci_rtc); } static inline u8 rtcss_read(struct davinci_rtc *davinci_rtc, u8 addr) { rtcif_wait(davinci_rtc); rtcif_write(davinci_rtc, PRTCIF_CTLR_DIR | PRTCIF_CTLR_BENL_LSB | addr, PRTCIF_CTLR); rtcif_wait(davinci_rtc); return rtcif_read(davinci_rtc, PRTCIF_LDATA); } static inline void davinci_rtcss_calendar_wait(struct davinci_rtc *davinci_rtc) { while (rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) & PRTCSS_RTC_CCTRL_CALBUSY) cpu_relax(); } static irqreturn_t davinci_rtc_interrupt(int irq, void *class_dev) { struct davinci_rtc *davinci_rtc = class_dev; unsigned long events = 0; u32 irq_flg; u8 alm_irq, tmr_irq; u8 rtc_ctrl, rtc_cctrl; int ret = IRQ_NONE; irq_flg = rtcif_read(davinci_rtc, PRTCIF_INTFLG) & PRTCIF_INTFLG_RTCSS; alm_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) & PRTCSS_RTC_CCTRL_ALMFLG; tmr_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL) & PRTCSS_RTC_CTRL_TMRFLG; if (irq_flg) { if (alm_irq) { events |= RTC_IRQF | RTC_AF; rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL); rtc_cctrl |= PRTCSS_RTC_CCTRL_ALMFLG; rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL); } else if (tmr_irq) { events |= RTC_IRQF | RTC_PF; rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL); rtc_ctrl |= PRTCSS_RTC_CTRL_TMRFLG; rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL); } rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS, PRTCIF_INTFLG); rtc_update_irq(davinci_rtc->rtc, 1, events); ret = IRQ_HANDLED; } return ret; } static int davinci_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev); u8 rtc_ctrl; unsigned long flags; int ret = 0; spin_lock_irqsave(&davinci_rtc_lock, flags); rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL); switch (cmd) { case RTC_WIE_ON: rtc_ctrl |= PRTCSS_RTC_CTRL_WEN | PRTCSS_RTC_CTRL_WDTFLG; break; case RTC_WIE_OFF: rtc_ctrl &= ~PRTCSS_RTC_CTRL_WEN; break; default: ret = -ENOIOCTLCMD; } rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL); spin_unlock_irqrestore(&davinci_rtc_lock, flags); return ret; } static int convertfromdays(u16 days, struct rtc_time *tm) { int tmp_days, year, mon; for (year = 2000;; year++) { tmp_days = rtc_year_days(1, 12, year); if (days >= tmp_days) days -= tmp_days; else { for (mon = 0;; mon++) { tmp_days = rtc_month_days(mon, year); if (days >= tmp_days) { days -= tmp_days; } else { tm->tm_year = year - 1900; tm->tm_mon = mon; tm->tm_mday = days + 1; break; } } break; } } return 0; } static int convert2days(u16 *days, struct rtc_time *tm) { int i; *days = 0; /* epoch == 1900 */ if (tm->tm_year < 100 || tm->tm_year > 199) return -EINVAL; for (i = 2000; i < 1900 + tm->tm_year; i++) *days += rtc_year_days(1, 12, i); *days += rtc_year_days(tm->tm_mday, tm->tm_mon, 1900 + tm->tm_year); return 0; } static int davinci_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev); u16 days = 0; u8 day0, day1; unsigned long flags; spin_lock_irqsave(&davinci_rtc_lock, flags); davinci_rtcss_calendar_wait(davinci_rtc); tm->tm_sec = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_SEC)); davinci_rtcss_calendar_wait(davinci_rtc); tm->tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_MIN)); davinci_rtcss_calendar_wait(davinci_rtc); tm->tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_HOUR)); davinci_rtcss_calendar_wait(davinci_rtc); day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY0); davinci_rtcss_calendar_wait(davinci_rtc); day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY1); spin_unlock_irqrestore(&davinci_rtc_lock, flags); days |= day1; days <<= 8; days |= day0; if (convertfromdays(days, tm) < 0) return -EINVAL; return 0; } static int davinci_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev); u16 days; u8 rtc_cctrl; unsigned long flags; if (convert2days(&days, tm) < 0) return -EINVAL; spin_lock_irqsave(&davinci_rtc_lock, flags); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, bin2bcd(tm->tm_sec), PRTCSS_RTC_SEC); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, bin2bcd(tm->tm_min), PRTCSS_RTC_MIN); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, bin2bcd(tm->tm_hour), PRTCSS_RTC_HOUR); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_DAY0); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_DAY1); rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL); rtc_cctrl |= PRTCSS_RTC_CCTRL_CAEN; rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL); spin_unlock_irqrestore(&davinci_rtc_lock, flags); return 0; } static int davinci_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev); unsigned long flags; u8 rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL); spin_lock_irqsave(&davinci_rtc_lock, flags); if (enabled) rtc_cctrl |= PRTCSS_RTC_CCTRL_DAEN | PRTCSS_RTC_CCTRL_HAEN | PRTCSS_RTC_CCTRL_MAEN | PRTCSS_RTC_CCTRL_ALMFLG | PRTCSS_RTC_CCTRL_AIEN; else rtc_cctrl &= ~PRTCSS_RTC_CCTRL_AIEN; davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL); spin_unlock_irqrestore(&davinci_rtc_lock, flags); return 0; } static int davinci_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev); u16 days = 0; u8 day0, day1; unsigned long flags; alm->time.tm_sec = 0; spin_lock_irqsave(&davinci_rtc_lock, flags); davinci_rtcss_calendar_wait(davinci_rtc); alm->time.tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AMIN)); davinci_rtcss_calendar_wait(davinci_rtc); alm->time.tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AHOUR)); davinci_rtcss_calendar_wait(davinci_rtc); day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY0); davinci_rtcss_calendar_wait(davinci_rtc); day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY1); spin_unlock_irqrestore(&davinci_rtc_lock, flags); days |= day1; days <<= 8; days |= day0; if (convertfromdays(days, &alm->time) < 0) return -EINVAL; alm->pending = !!(rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) & PRTCSS_RTC_CCTRL_AIEN); alm->enabled = alm->pending && device_may_wakeup(dev); return 0; } static int davinci_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev); unsigned long flags; u16 days; if (alm->time.tm_mday <= 0 && alm->time.tm_mon < 0 && alm->time.tm_year < 0) { struct rtc_time tm; unsigned long now, then; davinci_rtc_read_time(dev, &tm); rtc_tm_to_time(&tm, &now); alm->time.tm_mday = tm.tm_mday; alm->time.tm_mon = tm.tm_mon; alm->time.tm_year = tm.tm_year; rtc_tm_to_time(&alm->time, &then); if (then < now) { rtc_time_to_tm(now + 24 * 60 * 60, &tm); alm->time.tm_mday = tm.tm_mday; alm->time.tm_mon = tm.tm_mon; alm->time.tm_year = tm.tm_year; } } if (convert2days(&days, &alm->time) < 0) return -EINVAL; spin_lock_irqsave(&davinci_rtc_lock, flags); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_min), PRTCSS_RTC_AMIN); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_hour), PRTCSS_RTC_AHOUR); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_ADAY0); davinci_rtcss_calendar_wait(davinci_rtc); rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_ADAY1); spin_unlock_irqrestore(&davinci_rtc_lock, flags); return 0; } static const struct rtc_class_ops davinci_rtc_ops = { .ioctl = davinci_rtc_ioctl, .read_time = davinci_rtc_read_time, .set_time = davinci_rtc_set_time, .alarm_irq_enable = davinci_rtc_alarm_irq_enable, .read_alarm = davinci_rtc_read_alarm, .set_alarm = davinci_rtc_set_alarm, }; static int __init davinci_rtc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct davinci_rtc *davinci_rtc; struct resource *res; int ret = 0; davinci_rtc = devm_kzalloc(&pdev->dev, sizeof(struct davinci_rtc), GFP_KERNEL); if (!davinci_rtc) return -ENOMEM; davinci_rtc->irq = platform_get_irq(pdev, 0); if (davinci_rtc->irq < 0) return davinci_rtc->irq; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); davinci_rtc->base = devm_ioremap_resource(dev, res); if (IS_ERR(davinci_rtc->base)) return PTR_ERR(davinci_rtc->base); platform_set_drvdata(pdev, davinci_rtc); davinci_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &davinci_rtc_ops, THIS_MODULE); if (IS_ERR(davinci_rtc->rtc)) { dev_err(dev, "unable to register RTC device, err %d\n", ret); return PTR_ERR(davinci_rtc->rtc); } rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS, PRTCIF_INTFLG); rtcif_write(davinci_rtc, 0, PRTCIF_INTEN); rtcss_write(davinci_rtc, 0, PRTCSS_RTC_INTC_EXTENA1); rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CTRL); rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CCTRL); ret = devm_request_irq(dev, davinci_rtc->irq, davinci_rtc_interrupt, 0, "davinci_rtc", davinci_rtc); if (ret < 0) { dev_err(dev, "unable to register davinci RTC interrupt\n"); return ret; } /* Enable interrupts */ rtcif_write(davinci_rtc, PRTCIF_INTEN_RTCSS, PRTCIF_INTEN); rtcss_write(davinci_rtc, PRTCSS_RTC_INTC_EXTENA1_MASK, PRTCSS_RTC_INTC_EXTENA1); rtcss_write(davinci_rtc, PRTCSS_RTC_CCTRL_CAEN, PRTCSS_RTC_CCTRL); device_init_wakeup(&pdev->dev, 0); return 0; } static int __exit davinci_rtc_remove(struct platform_device *pdev) { struct davinci_rtc *davinci_rtc = platform_get_drvdata(pdev); device_init_wakeup(&pdev->dev, 0); rtcif_write(davinci_rtc, 0, PRTCIF_INTEN); return 0; } static struct platform_driver davinci_rtc_driver = { .remove = __exit_p(davinci_rtc_remove), .driver = { .name = "rtc_davinci", }, }; module_platform_driver_probe(davinci_rtc_driver, davinci_rtc_probe); MODULE_AUTHOR("Miguel Aguilar <miguel.aguilar@ridgerun.com>"); MODULE_DESCRIPTION("Texas Instruments DaVinci PRTC Driver"); MODULE_LICENSE("GPL");