// SPDX-License-Identifier: GPL-2.0-or-later/* * DS1286 Real Time Clock interface for Linux * * Copyright (C) 1998, 1999, 2000 Ralf Baechle * Copyright (C) 2008 Thomas Bogendoerfer * * Based on code written by Paul Gortmaker. */ #include <linux/module.h>#include <linux/rtc.h>#include <linux/platform_device.h>#include <linux/bcd.h>#include <linux/rtc/ds1286.h>#include <linux/io.h>#include <linux/slab.h> struct ds1286_priv {	struct rtc_device *rtc;	u32 __iomem *rtcregs;	spinlock_t lock;}; static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg){	return __raw_readl(&priv->rtcregs[reg]) & 0xff;} static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg){	__raw_writel(data, &priv->rtcregs[reg]);}  static int ds1286_alarm_irq_enable(struct device *dev, unsigned int enabled){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned long flags;	unsigned char val; 	/* Allow or mask alarm interrupts */	spin_lock_irqsave(&priv->lock, flags);	val = ds1286_rtc_read(priv, RTC_CMD);	if (enabled)		val &=  ~RTC_TDM;	else		val |=  RTC_TDM;	ds1286_rtc_write(priv, val, RTC_CMD);	spin_unlock_irqrestore(&priv->lock, flags); 	return 0;} #ifdef CONFIG_RTC_INTF_DEV static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned long flags;	unsigned char val; 	switch (cmd) {	case RTC_WIE_OFF:		/* Mask watchdog int. enab. bit	*/		spin_lock_irqsave(&priv->lock, flags);		val = ds1286_rtc_read(priv, RTC_CMD);		val |= RTC_WAM;		ds1286_rtc_write(priv, val, RTC_CMD);		spin_unlock_irqrestore(&priv->lock, flags);		break;	case RTC_WIE_ON:		/* Allow watchdog interrupts.	*/		spin_lock_irqsave(&priv->lock, flags);		val = ds1286_rtc_read(priv, RTC_CMD);		val &= ~RTC_WAM;		ds1286_rtc_write(priv, val, RTC_CMD);		spin_unlock_irqrestore(&priv->lock, flags);		break;	default:		return -ENOIOCTLCMD;	}	return 0;} #else#define ds1286_ioctl    NULL#endif #ifdef CONFIG_PROC_FS static int ds1286_proc(struct device *dev, struct seq_file *seq){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned char month, cmd, amode;	const char *s; 	month = ds1286_rtc_read(priv, RTC_MONTH);	seq_printf(seq,		   "oscillator\t: %s\n"		   "square_wave\t: %s\n",		   (month & RTC_EOSC) ? "disabled" : "enabled",		   (month & RTC_ESQW) ? "disabled" : "enabled"); 	amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) |		((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) |		((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7);	switch (amode) {	case 7:		s = "each minute";		break;	case 3:		s = "minutes match";		break;	case 1:		s = "hours and minutes match";		break;	case 0:		s = "days, hours and minutes match";		break;	default:		s = "invalid";		break;	}	seq_printf(seq, "alarm_mode\t: %s\n", s); 	cmd = ds1286_rtc_read(priv, RTC_CMD);	seq_printf(seq,		   "alarm_enable\t: %s\n"		   "wdog_alarm\t: %s\n"		   "alarm_mask\t: %s\n"		   "wdog_alarm_mask\t: %s\n"		   "interrupt_mode\t: %s\n"		   "INTB_mode\t: %s_active\n"		   "interrupt_pins\t: %s\n",		   (cmd & RTC_TDF) ? "yes" : "no",		   (cmd & RTC_WAF) ? "yes" : "no",		   (cmd & RTC_TDM) ? "disabled" : "enabled",		   (cmd & RTC_WAM) ? "disabled" : "enabled",		   (cmd & RTC_PU_LVL) ? "pulse" : "level",		   (cmd & RTC_IBH_LO) ? "low" : "high",		   (cmd & RTC_IPSW) ? "unswapped" : "swapped");	return 0;} #else#define ds1286_proc     NULL#endif static int ds1286_read_time(struct device *dev, struct rtc_time *tm){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned char save_control;	unsigned long flags;	unsigned long uip_watchdog = jiffies; 	/*	 * read RTC once any update in progress is done. The update	 * can take just over 2ms. We wait 10 to 20ms. There is no need to	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.	 * If you need to know *exactly* when a second has started, enable	 * periodic update complete interrupts, (via ioctl) and then	 * immediately read /dev/rtc which will block until you get the IRQ.	 * Once the read clears, read the RTC time (again via ioctl). Easy.	 */ 	if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)		while (time_before(jiffies, uip_watchdog + 2*HZ/100))			barrier(); 	/*	 * Only the values that we read from the RTC are set. We leave	 * tm_wday, tm_yday and tm_isdst untouched. Even though the	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated	 * by the RTC when initially set to a non-zero value.	 */	spin_lock_irqsave(&priv->lock, flags);	save_control = ds1286_rtc_read(priv, RTC_CMD);	ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD); 	tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS);	tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES);	tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f;	tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE);	tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f;	tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR); 	ds1286_rtc_write(priv, save_control, RTC_CMD);	spin_unlock_irqrestore(&priv->lock, flags); 	tm->tm_sec = bcd2bin(tm->tm_sec);	tm->tm_min = bcd2bin(tm->tm_min);	tm->tm_hour = bcd2bin(tm->tm_hour);	tm->tm_mday = bcd2bin(tm->tm_mday);	tm->tm_mon = bcd2bin(tm->tm_mon);	tm->tm_year = bcd2bin(tm->tm_year); 	/*	 * Account for differences between how the RTC uses the values	 * and how they are defined in a struct rtc_time;	 */	if (tm->tm_year < 45)		tm->tm_year += 30;	tm->tm_year += 40;	if (tm->tm_year < 70)		tm->tm_year += 100; 	tm->tm_mon--; 	return 0;} static int ds1286_set_time(struct device *dev, struct rtc_time *tm){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned char mon, day, hrs, min, sec;	unsigned char save_control;	unsigned int yrs;	unsigned long flags; 	yrs = tm->tm_year + 1900;	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */	day = tm->tm_mday;	hrs = tm->tm_hour;	min = tm->tm_min;	sec = tm->tm_sec; 	if (yrs < 1970)		return -EINVAL; 	yrs -= 1940;	if (yrs > 255)    /* They are unsigned */		return -EINVAL; 	if (yrs >= 100)		yrs -= 100; 	sec = bin2bcd(sec);	min = bin2bcd(min);	hrs = bin2bcd(hrs);	day = bin2bcd(day);	mon = bin2bcd(mon);	yrs = bin2bcd(yrs); 	spin_lock_irqsave(&priv->lock, flags);	save_control = ds1286_rtc_read(priv, RTC_CMD);	ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD); 	ds1286_rtc_write(priv, yrs, RTC_YEAR);	ds1286_rtc_write(priv, mon, RTC_MONTH);	ds1286_rtc_write(priv, day, RTC_DATE);	ds1286_rtc_write(priv, hrs, RTC_HOURS);	ds1286_rtc_write(priv, min, RTC_MINUTES);	ds1286_rtc_write(priv, sec, RTC_SECONDS);	ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND); 	ds1286_rtc_write(priv, save_control, RTC_CMD);	spin_unlock_irqrestore(&priv->lock, flags);	return 0;} static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned long flags; 	/*	 * Only the values that we read from the RTC are set. That	 * means only tm_wday, tm_hour, tm_min.	 */	spin_lock_irqsave(&priv->lock, flags);	alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f;	alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM)  & 0x1f;	alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM)    & 0x07;	ds1286_rtc_read(priv, RTC_CMD);	spin_unlock_irqrestore(&priv->lock, flags); 	alm->time.tm_min = bcd2bin(alm->time.tm_min);	alm->time.tm_hour = bcd2bin(alm->time.tm_hour);	alm->time.tm_sec = 0;	return 0;} static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm){	struct ds1286_priv *priv = dev_get_drvdata(dev);	unsigned char hrs, min, sec; 	hrs = alm->time.tm_hour;	min = alm->time.tm_min;	sec = alm->time.tm_sec; 	if (hrs >= 24)		hrs = 0xff; 	if (min >= 60)		min = 0xff; 	if (sec != 0)		return -EINVAL; 	min = bin2bcd(min);	hrs = bin2bcd(hrs); 	spin_lock(&priv->lock);	ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM);	ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM);	spin_unlock(&priv->lock); 	return 0;} static const struct rtc_class_ops ds1286_ops = {	.ioctl		= ds1286_ioctl,	.proc		= ds1286_proc,	.read_time	= ds1286_read_time,	.set_time	= ds1286_set_time,	.read_alarm	= ds1286_read_alarm,	.set_alarm	= ds1286_set_alarm,	.alarm_irq_enable = ds1286_alarm_irq_enable,}; static int ds1286_probe(struct platform_device *pdev){	struct rtc_device *rtc;	struct ds1286_priv *priv; 	priv = devm_kzalloc(&pdev->dev, sizeof(struct ds1286_priv), GFP_KERNEL);	if (!priv)		return -ENOMEM; 	priv->rtcregs = devm_platform_ioremap_resource(pdev, 0);	if (IS_ERR(priv->rtcregs))		return PTR_ERR(priv->rtcregs); 	spin_lock_init(&priv->lock);	platform_set_drvdata(pdev, priv);	rtc = devm_rtc_device_register(&pdev->dev, "ds1286", &ds1286_ops,					THIS_MODULE);	if (IS_ERR(rtc))		return PTR_ERR(rtc);	priv->rtc = rtc;	return 0;} static struct platform_driver ds1286_platform_driver = {	.driver		= {		.name	= "rtc-ds1286",	},	.probe		= ds1286_probe,}; module_platform_driver(ds1286_platform_driver); MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");MODULE_DESCRIPTION("DS1286 RTC driver");MODULE_LICENSE("GPL");MODULE_ALIAS("platform:rtc-ds1286");