/* * 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. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/module.h> #include <linux/rtc.h> #include <linux/platform_device.h> #include <linux/bcd.h> #include <linux/ds1286.h> #include <linux/io.h> #include <linux/slab.h> #define DRV_VERSION "1.0" 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 rtc_valid_tm(tm); } 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 resource *res; struct ds1286_priv *priv; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENODEV; priv = devm_kzalloc(&pdev->dev, sizeof(struct ds1286_priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->rtcregs = devm_ioremap_resource(&pdev->dev, res); 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", .owner = THIS_MODULE, }, .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_VERSION(DRV_VERSION); MODULE_ALIAS("platform:rtc-ds1286");