/* * An rtc driver for the Dallas DS1511 * * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp> * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Real time clock driver for the Dallas 1511 chip, which also * contains a watchdog timer. There is a tiny amount of code that * platform code could use to mess with the watchdog device a little * bit, but not a full watchdog driver. */ #include <linux/bcd.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/gfp.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/rtc.h> #include <linux/platform_device.h> #include <linux/io.h> #include <linux/module.h> #define DRV_VERSION "0.6" enum ds1511reg { DS1511_SEC = 0x0, DS1511_MIN = 0x1, DS1511_HOUR = 0x2, DS1511_DOW = 0x3, DS1511_DOM = 0x4, DS1511_MONTH = 0x5, DS1511_YEAR = 0x6, DS1511_CENTURY = 0x7, DS1511_AM1_SEC = 0x8, DS1511_AM2_MIN = 0x9, DS1511_AM3_HOUR = 0xa, DS1511_AM4_DATE = 0xb, DS1511_WD_MSEC = 0xc, DS1511_WD_SEC = 0xd, DS1511_CONTROL_A = 0xe, DS1511_CONTROL_B = 0xf, DS1511_RAMADDR_LSB = 0x10, DS1511_RAMDATA = 0x13 }; #define DS1511_BLF1 0x80 #define DS1511_BLF2 0x40 #define DS1511_PRS 0x20 #define DS1511_PAB 0x10 #define DS1511_TDF 0x08 #define DS1511_KSF 0x04 #define DS1511_WDF 0x02 #define DS1511_IRQF 0x01 #define DS1511_TE 0x80 #define DS1511_CS 0x40 #define DS1511_BME 0x20 #define DS1511_TPE 0x10 #define DS1511_TIE 0x08 #define DS1511_KIE 0x04 #define DS1511_WDE 0x02 #define DS1511_WDS 0x01 #define DS1511_RAM_MAX 0xff #define RTC_CMD DS1511_CONTROL_B #define RTC_CMD1 DS1511_CONTROL_A #define RTC_ALARM_SEC DS1511_AM1_SEC #define RTC_ALARM_MIN DS1511_AM2_MIN #define RTC_ALARM_HOUR DS1511_AM3_HOUR #define RTC_ALARM_DATE DS1511_AM4_DATE #define RTC_SEC DS1511_SEC #define RTC_MIN DS1511_MIN #define RTC_HOUR DS1511_HOUR #define RTC_DOW DS1511_DOW #define RTC_DOM DS1511_DOM #define RTC_MON DS1511_MONTH #define RTC_YEAR DS1511_YEAR #define RTC_CENTURY DS1511_CENTURY #define RTC_TIE DS1511_TIE #define RTC_TE DS1511_TE struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; /* virtual base address */ int size; /* amount of memory mapped */ int irq; unsigned int irqen; int alrm_sec; int alrm_min; int alrm_hour; int alrm_mday; spinlock_t lock; }; static DEFINE_SPINLOCK(ds1511_lock); static __iomem char *ds1511_base; static u32 reg_spacing = 1; static noinline void rtc_write(uint8_t val, uint32_t reg) { writeb(val, ds1511_base + (reg * reg_spacing)); } static inline void rtc_write_alarm(uint8_t val, enum ds1511reg reg) { rtc_write((val | 0x80), reg); } static noinline uint8_t rtc_read(enum ds1511reg reg) { return readb(ds1511_base + (reg * reg_spacing)); } static inline void rtc_disable_update(void) { rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD); } static void rtc_enable_update(void) { rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD); } /* * #define DS1511_WDOG_RESET_SUPPORT * * Uncomment this if you want to use these routines in * some platform code. */ #ifdef DS1511_WDOG_RESET_SUPPORT /* * just enough code to set the watchdog timer so that it * will reboot the system */ void ds1511_wdog_set(unsigned long deciseconds) { /* * the wdog timer can take 99.99 seconds */ deciseconds %= 10000; /* * set the wdog values in the wdog registers */ rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC); rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC); /* * set wdog enable and wdog 'steering' bit to issue a reset */ rtc_write(DS1511_WDE | DS1511_WDS, RTC_CMD); } void ds1511_wdog_disable(void) { /* * clear wdog enable and wdog 'steering' bits */ rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD); /* * clear the wdog counter */ rtc_write(0, DS1511_WD_MSEC); rtc_write(0, DS1511_WD_SEC); } #endif /* * set the rtc chip's idea of the time. * stupidly, some callers call with year unmolested; * and some call with year = year - 1900. thanks. */ static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm) { u8 mon, day, dow, hrs, min, sec, yrs, cen; unsigned long flags; /* * won't have to change this for a while */ if (rtc_tm->tm_year < 1900) { rtc_tm->tm_year += 1900; } if (rtc_tm->tm_year < 1970) { return -EINVAL; } yrs = rtc_tm->tm_year % 100; cen = rtc_tm->tm_year / 100; mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */ day = rtc_tm->tm_mday; dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */ hrs = rtc_tm->tm_hour; min = rtc_tm->tm_min; sec = rtc_tm->tm_sec; if ((mon > 12) || (day == 0)) { return -EINVAL; } if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year)) { return -EINVAL; } if ((hrs >= 24) || (min >= 60) || (sec >= 60)) { return -EINVAL; } /* * each register is a different number of valid bits */ sec = bin2bcd(sec) & 0x7f; min = bin2bcd(min) & 0x7f; hrs = bin2bcd(hrs) & 0x3f; day = bin2bcd(day) & 0x3f; mon = bin2bcd(mon) & 0x1f; yrs = bin2bcd(yrs) & 0xff; cen = bin2bcd(cen) & 0xff; spin_lock_irqsave(&ds1511_lock, flags); rtc_disable_update(); rtc_write(cen, RTC_CENTURY); rtc_write(yrs, RTC_YEAR); rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON); rtc_write(day, RTC_DOM); rtc_write(hrs, RTC_HOUR); rtc_write(min, RTC_MIN); rtc_write(sec, RTC_SEC); rtc_write(dow, RTC_DOW); rtc_enable_update(); spin_unlock_irqrestore(&ds1511_lock, flags); return 0; } static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) { unsigned int century; unsigned long flags; spin_lock_irqsave(&ds1511_lock, flags); rtc_disable_update(); rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f; rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f; rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f; rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f; rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7; rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f; rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f; century = rtc_read(RTC_CENTURY); rtc_enable_update(); spin_unlock_irqrestore(&ds1511_lock, flags); rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday); rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday); rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon); rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year); century = bcd2bin(century) * 100; /* * Account for differences between how the RTC uses the values * and how they are defined in a struct rtc_time; */ century += rtc_tm->tm_year; rtc_tm->tm_year = century - 1900; rtc_tm->tm_mon--; if (rtc_valid_tm(rtc_tm) < 0) { dev_err(dev, "retrieved date/time is not valid.\n"); rtc_time_to_tm(0, rtc_tm); } return 0; } /* * write the alarm register settings * * we only have the use to interrupt every second, otherwise * known as the update interrupt, or the interrupt if the whole * date/hours/mins/secs matches. the ds1511 has many more * permutations, but the kernel doesn't. */ static void ds1511_rtc_update_alarm(struct rtc_plat_data *pdata) { unsigned long flags; spin_lock_irqsave(&pdata->lock, flags); rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ? 0x80 : bin2bcd(pdata->alrm_mday) & 0x3f, RTC_ALARM_DATE); rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ? 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f, RTC_ALARM_HOUR); rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ? 0x80 : bin2bcd(pdata->alrm_min) & 0x7f, RTC_ALARM_MIN); rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ? 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f, RTC_ALARM_SEC); rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD); rtc_read(RTC_CMD1); /* clear interrupts */ spin_unlock_irqrestore(&pdata->lock, flags); } static int ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); if (pdata->irq <= 0) return -EINVAL; pdata->alrm_mday = alrm->time.tm_mday; pdata->alrm_hour = alrm->time.tm_hour; pdata->alrm_min = alrm->time.tm_min; pdata->alrm_sec = alrm->time.tm_sec; if (alrm->enabled) { pdata->irqen |= RTC_AF; } ds1511_rtc_update_alarm(pdata); return 0; } static int ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); if (pdata->irq <= 0) return -EINVAL; alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday; alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour; alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min; alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec; alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0; return 0; } static irqreturn_t ds1511_interrupt(int irq, void *dev_id) { struct platform_device *pdev = dev_id; struct rtc_plat_data *pdata = platform_get_drvdata(pdev); unsigned long events = 0; spin_lock(&pdata->lock); /* * read and clear interrupt */ if (rtc_read(RTC_CMD1) & DS1511_IRQF) { events = RTC_IRQF; if (rtc_read(RTC_ALARM_SEC) & 0x80) events |= RTC_UF; else events |= RTC_AF; if (likely(pdata->rtc)) rtc_update_irq(pdata->rtc, 1, events); } spin_unlock(&pdata->lock); return events ? IRQ_HANDLED : IRQ_NONE; } static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); if (pdata->irq <= 0) return -EINVAL; if (enabled) pdata->irqen |= RTC_AF; else pdata->irqen &= ~RTC_AF; ds1511_rtc_update_alarm(pdata); return 0; } static const struct rtc_class_ops ds1511_rtc_ops = { .read_time = ds1511_rtc_read_time, .set_time = ds1511_rtc_set_time, .read_alarm = ds1511_rtc_read_alarm, .set_alarm = ds1511_rtc_set_alarm, .alarm_irq_enable = ds1511_rtc_alarm_irq_enable, }; static ssize_t ds1511_nvram_read(struct file *filp, struct kobject *kobj, struct bin_attribute *ba, char *buf, loff_t pos, size_t size) { ssize_t count; /* * if count is more than one, turn on "burst" mode * turn it off when you're done */ if (size > 1) { rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD); } if (pos > DS1511_RAM_MAX) { pos = DS1511_RAM_MAX; } if (size + pos > DS1511_RAM_MAX + 1) { size = DS1511_RAM_MAX - pos + 1; } rtc_write(pos, DS1511_RAMADDR_LSB); for (count = 0; size > 0; count++, size--) { *buf++ = rtc_read(DS1511_RAMDATA); } if (count > 1) { rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD); } return count; } static ssize_t ds1511_nvram_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t size) { ssize_t count; /* * if count is more than one, turn on "burst" mode * turn it off when you're done */ if (size > 1) { rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD); } if (pos > DS1511_RAM_MAX) { pos = DS1511_RAM_MAX; } if (size + pos > DS1511_RAM_MAX + 1) { size = DS1511_RAM_MAX - pos + 1; } rtc_write(pos, DS1511_RAMADDR_LSB); for (count = 0; size > 0; count++, size--) { rtc_write(*buf++, DS1511_RAMDATA); } if (count > 1) { rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD); } return count; } static struct bin_attribute ds1511_nvram_attr = { .attr = { .name = "nvram", .mode = S_IRUGO | S_IWUSR, }, .size = DS1511_RAM_MAX, .read = ds1511_nvram_read, .write = ds1511_nvram_write, }; static int __devinit ds1511_rtc_probe(struct platform_device *pdev) { struct rtc_device *rtc; struct resource *res; struct rtc_plat_data *pdata; int ret = 0; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { return -ENODEV; } pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; pdata->size = resource_size(res); if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size, pdev->name)) return -EBUSY; ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size); if (!ds1511_base) return -ENOMEM; pdata->ioaddr = ds1511_base; pdata->irq = platform_get_irq(pdev, 0); /* * turn on the clock and the crystal, etc. */ rtc_write(0, RTC_CMD); rtc_write(0, RTC_CMD1); /* * clear the wdog counter */ rtc_write(0, DS1511_WD_MSEC); rtc_write(0, DS1511_WD_SEC); /* * start the clock */ rtc_enable_update(); /* * check for a dying bat-tree */ if (rtc_read(RTC_CMD1) & DS1511_BLF1) { dev_warn(&pdev->dev, "voltage-low detected.\n"); } spin_lock_init(&pdata->lock); platform_set_drvdata(pdev, pdata); /* * if the platform has an interrupt in mind for this device, * then by all means, set it */ if (pdata->irq > 0) { rtc_read(RTC_CMD1); if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt, IRQF_SHARED, pdev->name, pdev) < 0) { dev_warn(&pdev->dev, "interrupt not available.\n"); pdata->irq = 0; } } rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); pdata->rtc = rtc; ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr); if (ret) rtc_device_unregister(pdata->rtc); return ret; } static int __devexit ds1511_rtc_remove(struct platform_device *pdev) { struct rtc_plat_data *pdata = platform_get_drvdata(pdev); sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr); rtc_device_unregister(pdata->rtc); if (pdata->irq > 0) { /* * disable the alarm interrupt */ rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD); rtc_read(RTC_CMD1); } return 0; } /* work with hotplug and coldplug */ MODULE_ALIAS("platform:ds1511"); static struct platform_driver ds1511_rtc_driver = { .probe = ds1511_rtc_probe, .remove = __devexit_p(ds1511_rtc_remove), .driver = { .name = "ds1511", .owner = THIS_MODULE, }, }; module_platform_driver(ds1511_rtc_driver); MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>"); MODULE_DESCRIPTION("Dallas DS1511 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION);