diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1553.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1553.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c new file mode 100644 index 00000000000..20900149547 --- /dev/null +++ b/drivers/rtc/rtc-ds1553.c @@ -0,0 +1,414 @@ +/* + * An rtc driver for the Dallas DS1553 + * + * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp> + * + * 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. + */ + +#include <linux/bcd.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/jiffies.h> +#include <linux/interrupt.h> +#include <linux/rtc.h> +#include <linux/platform_device.h> +#include <linux/io.h> + +#define DRV_VERSION "0.1" + +#define RTC_REG_SIZE 0x2000 +#define RTC_OFFSET 0x1ff0 + +#define RTC_FLAGS (RTC_OFFSET + 0) +#define RTC_SECONDS_ALARM (RTC_OFFSET + 2) +#define RTC_MINUTES_ALARM (RTC_OFFSET + 3) +#define RTC_HOURS_ALARM (RTC_OFFSET + 4) +#define RTC_DATE_ALARM (RTC_OFFSET + 5) +#define RTC_INTERRUPTS (RTC_OFFSET + 6) +#define RTC_WATCHDOG (RTC_OFFSET + 7) +#define RTC_CONTROL (RTC_OFFSET + 8) +#define RTC_CENTURY (RTC_OFFSET + 8) +#define RTC_SECONDS (RTC_OFFSET + 9) +#define RTC_MINUTES (RTC_OFFSET + 10) +#define RTC_HOURS (RTC_OFFSET + 11) +#define RTC_DAY (RTC_OFFSET + 12) +#define RTC_DATE (RTC_OFFSET + 13) +#define RTC_MONTH (RTC_OFFSET + 14) +#define RTC_YEAR (RTC_OFFSET + 15) + +#define RTC_CENTURY_MASK 0x3f +#define RTC_SECONDS_MASK 0x7f +#define RTC_DAY_MASK 0x07 + +/* Bits in the Control/Century register */ +#define RTC_WRITE 0x80 +#define RTC_READ 0x40 + +/* Bits in the Seconds register */ +#define RTC_STOP 0x80 + +/* Bits in the Flags register */ +#define RTC_FLAGS_AF 0x40 +#define RTC_FLAGS_BLF 0x10 + +/* Bits in the Interrupts register */ +#define RTC_INTS_AE 0x80 + +struct rtc_plat_data { + struct rtc_device *rtc; + void __iomem *ioaddr; + unsigned long baseaddr; + unsigned long last_jiffies; + int irq; + unsigned int irqen; + int alrm_sec; + int alrm_min; + int alrm_hour; + int alrm_mday; +}; + +static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + void __iomem *ioaddr = pdata->ioaddr; + u8 century; + + century = BIN2BCD((tm->tm_year + 1900) / 100); + + writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL); + + writeb(BIN2BCD(tm->tm_year % 100), ioaddr + RTC_YEAR); + writeb(BIN2BCD(tm->tm_mon + 1), ioaddr + RTC_MONTH); + writeb(BIN2BCD(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY); + writeb(BIN2BCD(tm->tm_mday), ioaddr + RTC_DATE); + writeb(BIN2BCD(tm->tm_hour), ioaddr + RTC_HOURS); + writeb(BIN2BCD(tm->tm_min), ioaddr + RTC_MINUTES); + writeb(BIN2BCD(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS); + + /* RTC_CENTURY and RTC_CONTROL share same register */ + writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY); + writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); + return 0; +} + +static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + void __iomem *ioaddr = pdata->ioaddr; + unsigned int year, month, day, hour, minute, second, week; + unsigned int century; + + /* give enough time to update RTC in case of continuous read */ + if (pdata->last_jiffies == jiffies) + msleep(1); + pdata->last_jiffies = jiffies; + writeb(RTC_READ, ioaddr + RTC_CONTROL); + second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK; + minute = readb(ioaddr + RTC_MINUTES); + hour = readb(ioaddr + RTC_HOURS); + day = readb(ioaddr + RTC_DATE); + week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK; + month = readb(ioaddr + RTC_MONTH); + year = readb(ioaddr + RTC_YEAR); + century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; + writeb(0, ioaddr + RTC_CONTROL); + tm->tm_sec = BCD2BIN(second); + tm->tm_min = BCD2BIN(minute); + tm->tm_hour = BCD2BIN(hour); + tm->tm_mday = BCD2BIN(day); + tm->tm_wday = BCD2BIN(week); + tm->tm_mon = BCD2BIN(month) - 1; + /* year is 1900 + tm->tm_year */ + tm->tm_year = BCD2BIN(year) + BCD2BIN(century) * 100 - 1900; + + if (rtc_valid_tm(tm) < 0) { + dev_err(dev, "retrieved date/time is not valid.\n"); + rtc_time_to_tm(0, tm); + } + return 0; +} + +static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata) +{ + void __iomem *ioaddr = pdata->ioaddr; + unsigned long flags; + + spin_lock_irqsave(&pdata->rtc->irq_lock, flags); + writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ? + 0x80 : BIN2BCD(pdata->alrm_mday), + ioaddr + RTC_DATE_ALARM); + writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ? + 0x80 : BIN2BCD(pdata->alrm_hour), + ioaddr + RTC_HOURS_ALARM); + writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ? + 0x80 : BIN2BCD(pdata->alrm_min), + ioaddr + RTC_MINUTES_ALARM); + writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ? + 0x80 : BIN2BCD(pdata->alrm_sec), + ioaddr + RTC_SECONDS_ALARM); + writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS); + readb(ioaddr + RTC_FLAGS); /* clear interrupts */ + spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); +} + +static int ds1553_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; + ds1553_rtc_update_alarm(pdata); + return 0; +} + +static int ds1553_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 ds1553_rtc_interrupt(int irq, void *dev_id, + struct pt_regs *regs) +{ + struct platform_device *pdev = dev_id; + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + void __iomem *ioaddr = pdata->ioaddr; + unsigned long events = RTC_IRQF; + + /* read and clear interrupt */ + if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF)) + return IRQ_NONE; + if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80) + events |= RTC_UF; + else + events |= RTC_AF; + rtc_update_irq(&pdata->rtc->class_dev, 1, events); + return IRQ_HANDLED; +} + +static void ds1553_rtc_release(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + + if (pdata->irq >= 0) { + pdata->irqen = 0; + ds1553_rtc_update_alarm(pdata); + } +} + +static int ds1553_rtc_ioctl(struct device *dev, unsigned int cmd, + unsigned long arg) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + + if (pdata->irq < 0) + return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */ + switch (cmd) { + case RTC_AIE_OFF: + pdata->irqen &= ~RTC_AF; + ds1553_rtc_update_alarm(pdata); + break; + case RTC_AIE_ON: + pdata->irqen |= RTC_AF; + ds1553_rtc_update_alarm(pdata); + break; + case RTC_UIE_OFF: + pdata->irqen &= ~RTC_UF; + ds1553_rtc_update_alarm(pdata); + break; + case RTC_UIE_ON: + pdata->irqen |= RTC_UF; + ds1553_rtc_update_alarm(pdata); + break; + default: + return -ENOIOCTLCMD; + } + return 0; +} + +static struct rtc_class_ops ds1553_rtc_ops = { + .read_time = ds1553_rtc_read_time, + .set_time = ds1553_rtc_set_time, + .read_alarm = ds1553_rtc_read_alarm, + .set_alarm = ds1553_rtc_set_alarm, + .release = ds1553_rtc_release, + .ioctl = ds1553_rtc_ioctl, +}; + +static ssize_t ds1553_nvram_read(struct kobject *kobj, char *buf, + loff_t pos, size_t size) +{ + struct platform_device *pdev = + to_platform_device(container_of(kobj, struct device, kobj)); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + void __iomem *ioaddr = pdata->ioaddr; + ssize_t count; + + for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--) + *buf++ = readb(ioaddr + pos++); + return count; +} + +static ssize_t ds1553_nvram_write(struct kobject *kobj, char *buf, + loff_t pos, size_t size) +{ + struct platform_device *pdev = + to_platform_device(container_of(kobj, struct device, kobj)); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + void __iomem *ioaddr = pdata->ioaddr; + ssize_t count; + + for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--) + writeb(*buf++, ioaddr + pos++); + return count; +} + +static struct bin_attribute ds1553_nvram_attr = { + .attr = { + .name = "nvram", + .mode = S_IRUGO | S_IWUGO, + .owner = THIS_MODULE, + }, + .size = RTC_OFFSET, + .read = ds1553_nvram_read, + .write = ds1553_nvram_write, +}; + +static int __init ds1553_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + struct resource *res; + unsigned int cen, sec; + struct rtc_plat_data *pdata = NULL; + void __iomem *ioaddr = NULL; + int ret = 0; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + pdata->irq = -1; + if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) { + ret = -EBUSY; + goto out; + } + pdata->baseaddr = res->start; + ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE); + if (!ioaddr) { + ret = -ENOMEM; + goto out; + } + pdata->ioaddr = ioaddr; + pdata->irq = platform_get_irq(pdev, 0); + + /* turn RTC on if it was not on */ + sec = readb(ioaddr + RTC_SECONDS); + if (sec & RTC_STOP) { + sec &= RTC_SECONDS_MASK; + cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; + writeb(RTC_WRITE, ioaddr + RTC_CONTROL); + writeb(sec, ioaddr + RTC_SECONDS); + writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); + } + if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF) + dev_warn(&pdev->dev, "voltage-low detected.\n"); + + if (pdata->irq >= 0) { + writeb(0, ioaddr + RTC_INTERRUPTS); + if (request_irq(pdata->irq, ds1553_rtc_interrupt, IRQF_SHARED, + pdev->name, pdev) < 0) { + dev_warn(&pdev->dev, "interrupt not available.\n"); + pdata->irq = -1; + } + } + + rtc = rtc_device_register(pdev->name, &pdev->dev, + &ds1553_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) { + ret = PTR_ERR(rtc); + goto out; + } + pdata->rtc = rtc; + pdata->last_jiffies = jiffies; + platform_set_drvdata(pdev, pdata); + sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr); + return 0; + out: + if (pdata->irq >= 0) + free_irq(pdata->irq, pdev); + if (ioaddr) + iounmap(ioaddr); + if (pdata->baseaddr) + release_mem_region(pdata->baseaddr, RTC_REG_SIZE); + kfree(pdata); + return ret; +} + +static int __devexit ds1553_rtc_remove(struct platform_device *pdev) +{ + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + + sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr); + rtc_device_unregister(pdata->rtc); + if (pdata->irq >= 0) { + writeb(0, pdata->ioaddr + RTC_INTERRUPTS); + free_irq(pdata->irq, pdev); + } + iounmap(pdata->ioaddr); + release_mem_region(pdata->baseaddr, RTC_REG_SIZE); + kfree(pdata); + return 0; +} + +static struct platform_driver ds1553_rtc_driver = { + .probe = ds1553_rtc_probe, + .remove = __devexit_p(ds1553_rtc_remove), + .driver = { + .name = "ds1553", + .owner = THIS_MODULE, + }, +}; + +static __init int ds1553_init(void) +{ + return platform_driver_register(&ds1553_rtc_driver); +} + +static __exit void ds1553_exit(void) +{ + return platform_driver_unregister(&ds1553_rtc_driver); +} + +module_init(ds1553_init); +module_exit(ds1553_exit); + +MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); +MODULE_DESCRIPTION("Dallas DS1553 RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); |