--- /dev/null
+/*
+ * 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 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;
+ 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 ds1511_rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct rtc_plat_data *pdata;
+ int ret = 0;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ds1511_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ds1511_base))
+ return PTR_ERR(ds1511_base);
+ 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);
+
+ pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+ &ds1511_rtc_ops, THIS_MODULE);
+ if (IS_ERR(pdata->rtc))
+ return PTR_ERR(pdata->rtc);
+
+ /*
+ * 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;
+ }
+ }
+
+ ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
+ if (ret)
+ dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
+ ds1511_nvram_attr.attr.name);
+
+ return 0;
+}
+
+static int 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);
+ 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 = ds1511_rtc_remove,
+ .driver = {
+ .name = "ds1511",
+ },
+};
+
+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);
Code Review / kvmfornfv.git / blobdiff