diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1286.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1286.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1286.c b/drivers/rtc/rtc-ds1286.c new file mode 100644 index 0000000000..7acf849d49 --- /dev/null +++ b/drivers/rtc/rtc-ds1286.c @@ -0,0 +1,358 @@ +// 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"); |