]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
Platform real time clock driver for Dallas 1511 chip
authorAndrew Sharp <andy.sharp@onstor.com>
Wed, 6 Feb 2008 09:38:46 +0000 (01:38 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Wed, 6 Feb 2008 18:41:13 +0000 (10:41 -0800)
Add RTC support for DS1511 RTC/WDT chip.

Signed-off-by: Andy Sharp <andy.sharp@onstor.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-ds1511.c [new file with mode: 0644]

index 0cc448c0edddbe2d656e7001b1e47d0e6b512576..4a39b76aeacd2377d70f8e769535b774afb08e47 100644 (file)
@@ -312,6 +312,16 @@ config RTC_DRV_DS1302
        help
          If you say yes here you get support for the Dallas DS1302 RTC chips.
 
+config RTC_DRV_DS1511
+       tristate "Dallas DS1511"
+       depends on RTC_CLASS
+       help
+         If you say yes here you get support for the
+         Dallas DS1511 timekeeping/watchdog chip.
+
+         This driver can also be built as a module. If so, the module
+         will be called rtc-ds1511.
+
 config RTC_DRV_DS1553
        tristate "Maxim/Dallas DS1553"
        help
index b5c3d3996444ddaf346f4dba1f76bcb03663e51d..36586c28cefcf3e0c90616745ec510e49dcdf421 100644 (file)
@@ -25,6 +25,7 @@ obj-$(CONFIG_RTC_DRV_DS1216)  += rtc-ds1216.o
 obj-$(CONFIG_RTC_DRV_DS1302)   += rtc-ds1302.o
 obj-$(CONFIG_RTC_DRV_DS1307)   += rtc-ds1307.o
 obj-$(CONFIG_RTC_DRV_DS1374)   += rtc-ds1374.o
+obj-$(CONFIG_RTC_DRV_DS1511)   += rtc-ds1511.o
 obj-$(CONFIG_RTC_DRV_DS1553)   += rtc-ds1553.o
 obj-$(CONFIG_RTC_DRV_DS1672)   += rtc-ds1672.o
 obj-$(CONFIG_RTC_DRV_DS1742)   += rtc-ds1742.o
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
new file mode 100644 (file)
index 0000000..d74b808
--- /dev/null
@@ -0,0 +1,656 @@
+/*
+ * An rtc driver for the Dallas DS1511
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ * Copyright (C) 2007 Andrew Sharp <andy.sharp@onstor.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/delay.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/io.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 */
+       unsigned long baseaddr;         /* physical 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;
+};
+
+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.
+ */
+ int
+ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
+{
+       u8 mon, day, dow, hrs, min, sec, yrs, cen;
+       unsigned int 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;
+}
+
+ int
+ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
+{
+       unsigned int century;
+       unsigned int 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->rtc->irq_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->rtc->irq_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 = RTC_IRQF;
+
+       /*
+        * read and clear interrupt
+        */
+       if (!(rtc_read(RTC_CMD1) & DS1511_IRQF)) {
+               return IRQ_NONE;
+       }
+       if (rtc_read(RTC_ALARM_SEC) & 0x80) {
+               events |= RTC_UF;
+       } else {
+               events |= RTC_AF;
+       }
+       rtc_update_irq(pdata->rtc, 1, events);
+       return IRQ_HANDLED;
+}
+
+ static void
+ds1511_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;
+               ds1511_rtc_update_alarm(pdata);
+       }
+}
+
+ static int
+ds1511_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;
+               ds1511_rtc_update_alarm(pdata);
+               break;
+       case RTC_AIE_ON:
+               pdata->irqen |= RTC_AF;
+               ds1511_rtc_update_alarm(pdata);
+               break;
+       case RTC_UIE_OFF:
+               pdata->irqen &= ~RTC_UF;
+               ds1511_rtc_update_alarm(pdata);
+               break;
+       case RTC_UIE_ON:
+               pdata->irqen |= RTC_UF;
+               ds1511_rtc_update_alarm(pdata);
+               break;
+       default:
+               return -ENOIOCTLCMD;
+       }
+       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,
+       .release        = ds1511_rtc_release,
+       .ioctl          = ds1511_rtc_ioctl,
+};
+
+ static ssize_t
+ds1511_nvram_read(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 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_IWUGO,
+               .owner = THIS_MODULE,
+       },
+       .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 = 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;
+       pdata->size = res->end - res->start + 1;
+       if (!request_mem_region(res->start, pdata->size, pdev->name)) {
+               ret = -EBUSY;
+               goto out;
+       }
+       pdata->baseaddr = res->start;
+       pdata->size = pdata->size;
+       ds1511_base = ioremap(pdata->baseaddr, pdata->size);
+       if (!ds1511_base) {
+               ret = -ENOMEM;
+               goto out;
+       }
+       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");
+       }
+
+       /*
+        * 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 (request_irq(pdata->irq, ds1511_interrupt,
+                       IRQF_DISABLED | 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, &ds1511_rtc_ops,
+               THIS_MODULE);
+       if (IS_ERR(rtc)) {
+               ret = PTR_ERR(rtc);
+               goto out;
+       }
+       pdata->rtc = rtc;
+       platform_set_drvdata(pdev, pdata);
+       ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
+       if (ret) {
+               goto out;
+       }
+       return 0;
+ out:
+       if (pdata->rtc) {
+               rtc_device_unregister(pdata->rtc);
+       }
+       if (pdata->irq >= 0) {
+               free_irq(pdata->irq, pdev);
+       }
+       if (ds1511_base) {
+               iounmap(ds1511_base);
+               ds1511_base = NULL;
+       }
+       if (pdata->baseaddr) {
+               release_mem_region(pdata->baseaddr, pdata->size);
+       }
+
+       kfree(pdata);
+       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);
+       pdata->rtc = NULL;
+       if (pdata->irq >= 0) {
+               /*
+                * disable the alarm interrupt
+                */
+               rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
+               rtc_read(RTC_CMD1);
+               free_irq(pdata->irq, pdev);
+       }
+       iounmap(pdata->ioaddr);
+       ds1511_base = NULL;
+       release_mem_region(pdata->baseaddr, pdata->size);
+       kfree(pdata);
+       return 0;
+}
+
+static struct platform_driver ds1511_rtc_driver = {
+       .probe          = ds1511_rtc_probe,
+       .remove         = __devexit_p(ds1511_rtc_remove),
+       .driver         = {
+               .name   = "ds1511",
+               .owner  = THIS_MODULE,
+       },
+};
+
+ static int __init
+ds1511_rtc_init(void)
+{
+       return platform_driver_register(&ds1511_rtc_driver);
+}
+
+ static void __exit
+ds1511_rtc_exit(void)
+{
+       return platform_driver_unregister(&ds1511_rtc_driver);
+}
+
+module_init(ds1511_rtc_init);
+module_exit(ds1511_rtc_exit);
+
+MODULE_AUTHOR("Andrew Sharp <andy.sharp@onstor.com>");
+MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);