diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/rtc/rtc-davinci.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-davinci.c b/drivers/rtc/rtc-davinci.c new file mode 100644 index 000000000..6bef0f235 --- /dev/null +++ b/drivers/rtc/rtc-davinci.c @@ -0,0 +1,512 @@ +// 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 void 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; + } + } +} + +static void convert2days(u16 *days, struct rtc_time *tm) +{ + int i; + *days = 0; + + 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); +} + +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; + + convertfromdays(days, tm); + + 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; + + convert2days(&days, tm); + + 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; + + convertfromdays(days, &alm->time); + + 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; + + convert2days(&days, &alm->time); + + 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; + 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; + + davinci_rtc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(davinci_rtc->base)) + return PTR_ERR(davinci_rtc->base); + + platform_set_drvdata(pdev, davinci_rtc); + + davinci_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(davinci_rtc->rtc)) + return PTR_ERR(davinci_rtc->rtc); + + davinci_rtc->rtc->ops = &davinci_rtc_ops; + davinci_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + davinci_rtc->rtc->range_max = RTC_TIMESTAMP_BEGIN_2000 + (1 << 16) * 86400ULL - 1; + + 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 devm_rtc_register_device(davinci_rtc->rtc); +} + +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"); |