[PATCH 01/02 resend] RTC: Add driver for DS1685 family of real time clocks

From: Joshua Kinard
Date: Fri Dec 12 2014 - 17:22:17 EST

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From: Joshua Kinard <kumba@xxxxxxxxxx>

This adds a driver for the Dallas/Maxim DS1685-family of RTC chips. It
supports the DS1685/DS1687, DS1688/DS1691, DS1689/DS1693, DS17285/DS17287,
DS17485/DS17487, and DS17885/DS17887 RTC chips. These chips are commonly found
in SGI O2 and SGI Octane systems. It was originally derived from a driver
patch submitted by Matthias Fuchs many years ago for use in EPPC-405-UC
modules, which also used these RTCs. In addition to the time-keeping
functions, this RTC also handles the shutdown mechanism of the O2 and Octane
and acts as a partial NVRAM for the boot PROMS in these systems.

Verified on both an SGI O2 and an SGI Octane.

Signed-off-by: Joshua Kinard <kumba@xxxxxxxxxx>
---
MAINTAINERS | 6
drivers/rtc/Kconfig | 90 +
drivers/rtc/Makefile | 1
drivers/rtc/rtc-ds1685.c | 2252 +++++++++++++++++++++++++++++++++++
include/linux/rtc/ds1685.h | 375 +++++
5 files changed, 2724 insertions(+)
create mode 100644 drivers/rtc/rtc-ds1685.c
create mode 100644 include/linux/rtc/ds1685.h

The checkpatch errors regarding "Macros with complex values should be enclosed
in parenthesis" should be fine. That macro construct I copied from elsewhere
in the kernel, and I don't think wrapping them in parenthesis helps at all.
Please let me know of any problems, thanks!

linux-rtc-ds1685.patch
diff --git a/MAINTAINERS b/MAINTAINERS
index e186bf9..d081504 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2915,6 +2915,12 @@ S: Supported
F: drivers/input/touchscreen/cyttsp*
F: include/linux/input/cyttsp.h

+DALLAS/MAXIM DS1685-FAMILY REAL TIME CLOCK
+M: Joshua Kinard <kumba@xxxxxxxxxx>
+S: Maintained
+F: drivers/rtc/rtc-ds1685.c
+F: include/linux/rtc/ds1685.h
+
DAMA SLAVE for AX.25
M: Joerg Reuter <jreuter@xxxxxxxx>
W: http://yaina.de/jreuter/
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index f15cddf..f5693c4 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -790,6 +790,96 @@ config RTC_DRV_DS1553
This driver can also be built as a module. If so, the module
will be called rtc-ds1553.

+config RTC_DRV_DS1685_FAMILY
+ tristate "Dallas/Maxim DS1685 Family"
+ help
+ If you say yes here you get support for the Dallas/Maxim DS1685
+ family of real time chips. This family includes the DS1685/DS1687,
+ DS1689/DS1693, DS17285/DS17287, DS17485/DS17487, and
+ DS17885/DS17887 chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-ds1685.
+
+choice
+ prompt "Subtype"
+ depends on RTC_DRV_DS1685_FAMILY
+ default RTC_DRV_DS1685
+
+config RTC_DRV_DS1685
+ bool "DS1685/DS1687"
+ help
+ This enables support for the Dallas/Maxim DS1685/DS1687 real time
+ clock chip.
+
+ This chip is commonly found in SGI O2 (IP32) and SGI Octane (IP30)
+ systems, as well as EPPC-405-UC modules by electronic system design
+ GmbH.
+
+config RTC_DRV_DS1689
+ bool "DS1689/DS1693"
+ help
+ This enables support for the Dallas/Maxim DS1689/DS1693 real time
+ clock chip.
+
+ This is an older RTC chip, supplanted by the DS1685/DS1687 above,
+ which supports a few minor features such as Vcc, Vbat, and Power
+ Cycle counters, plus a customer-specific, 8-byte ROM/Serial number.
+
+ It also works for the even older DS1688/DS1691 RTC chips, which are
+ virtually the same and carry the same model number. Both chips
+ have 114 bytes of user NVRAM.
+
+config RTC_DRV_DS17285
+ bool "DS17285/DS17287"
+ help
+ This enables support for the Dallas/Maxim DS17285/DS17287 real time
+ clock chip.
+
+ This chip features 2kb of extended NV-SRAM. It may possibly be
+ found in some SGI O2 systems (rare).
+
+config RTC_DRV_DS17485
+ bool "DS17485/DS17487"
+ help
+ This enables support for the Dallas/Maxim DS17485/DS17487 real time
+ clock chip.
+
+ This chip features 4kb of extended NV-SRAM.
+
+config RTC_DRV_DS17885
+ bool "DS17885/DS17887"
+ help
+ This enables support for the Dallas/Maxim DS17885/DS17887 real time
+ clock chip.
+
+ This chip features 8kb of extended NV-SRAM.
+
+endchoice
+
+config RTC_DS1685_PROC_REGS
+ bool "Display register values in /proc"
+ depends on RTC_DRV_DS1685_FAMILY && PROC_FS
+ help
+ Enable this to display a readout of all of the RTC registers in
+ /proc/drivers/rtc. Keep in mind that this can potentially lead
+ to lost interrupts, as reading Control Register C will clear
+ all pending IRQ flags.
+
+ Unless you are debugging this driver, choose N.
+
+config RTC_DS1685_SYSFS_REGS
+ bool "SysFS access to RTC register bits"
+ depends on RTC_DRV_DS1685_FAMILY && SYSFS
+ help
+ Enable this to provide access to the RTC control register bits
+ in /sys. Some of the bits are read-write, others are read-only.
+
+ Keep in mind that reading Control C's bits automatically clears
+ all pending IRQ flags - this can cause lost interrupts.
+
+ If you know that you need access to these bits, choose Y, Else N.
+
config RTC_DRV_DS1742
tristate "Maxim/Dallas DS1742/1743"
depends on HAS_IOMEM
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index c8ef3e1..1b45334 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_RTC_DRV_DS1390) += rtc-ds1390.o
obj-$(CONFIG_RTC_DRV_DS1511) += rtc-ds1511.o
obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o
obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o
+obj-$(CONFIG_RTC_DRV_DS1685_FAMILY) += rtc-ds1685.o
obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o
obj-$(CONFIG_RTC_DRV_DS2404) += rtc-ds2404.o
obj-$(CONFIG_RTC_DRV_DS3232) += rtc-ds3232.o
diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c
new file mode 100644
index 0000000..8c3bfcb
--- /dev/null
+++ b/drivers/rtc/rtc-ds1685.c
@@ -0,0 +1,2252 @@
+/*
+ * An rtc driver for the Dallas/Maxim DS1685/DS1687 and related real-time
+ * chips.
+ *
+ * Copyright (C) 2011-2014 Joshua Kinard <kumba@xxxxxxxxxx>.
+ * Copyright (C) 2009 Matthias Fuchs <matthias.fuchs@xxxxxxxxxxxxxxxxxxx>.
+ *
+ * References:
+ * DS1685/DS1687 3V/5V Real-Time Clocks, 19-5215, Rev 4/10.
+ * DS17x85/DS17x87 3V/5V Real-Time Clocks, 19-5222, Rev 4/10.
+ * DS1689/DS1693 3V/5V Serialized Real-Time Clocks, Rev 112105.
+ * Application Note 90, Using the Multiplex Bus RTC Extended Features.
+ *
+ * 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/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/workqueue.h>
+
+#include <linux/rtc/ds1685.h>
+
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#endif
+
+#define DRV_VERSION "0.42.0"
+
+
+/* ----------------------------------------------------------------------- */
+/* Standard read/write functions if platform does not provide overrides */
+
+/**
+ * ds1685_read - read a value from an rtc register.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @reg: the register address to read.
+ */
+static u8
+ds1685_read(struct ds1685_priv *rtc, int reg)
+{
+ return readb((u8 __iomem *)rtc->regs +
+ (reg * rtc->regstep));
+}
+
+/**
+ * ds1685_write - write a value to an rtc register.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @reg: the register address to write.
+ * @value: value to write to the register.
+ */
+static void
+ds1685_write(struct ds1685_priv *rtc, int reg, u8 value)
+{
+ writeb(value, ((u8 __iomem *)rtc->regs +
+ (reg * rtc->regstep)));
+}
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* Inlined functions */
+
+/**
+ * ds1685_rtc_bcd2bin - bcd2bin wrapper in case platform doesn't support BCD.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @val: u8 time value to consider converting.
+ * @bcd_mask: u8 mask value if BCD mode is used.
+ * @bin_mask: u8 mask value if BIN mode is used.
+ *
+ * Returns the value, converted to BIN if originally in BCD and bcd_mode TRUE.
+ */
+static inline u8
+ds1685_rtc_bcd2bin(struct ds1685_priv *rtc, u8 val, u8 bcd_mask, u8 bin_mask)
+{
+ if (rtc->bcd_mode)
+ return (bcd2bin(val) & bcd_mask);
+
+ return (val & bin_mask);
+}
+
+/**
+ * ds1685_rtc_bin2bcd - bin2bcd wrapper in case platform doesn't support BCD.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @val: u8 time value to consider converting.
+ * @bin_mask: u8 mask value if BIN mode is used.
+ * @bcd_mask: u8 mask value if BCD mode is used.
+ *
+ * Returns the value, converted to BCD if originally in BIN and bcd_mode TRUE.
+ */
+static inline u8
+ds1685_rtc_bin2bcd(struct ds1685_priv *rtc, u8 val, u8 bin_mask, u8 bcd_mask)
+{
+ if (rtc->bcd_mode)
+ return (bin2bcd(val) & bcd_mask);
+
+ return (val & bin_mask);
+}
+
+/**
+ * ds1685_rtc_switch_to_bank0 - switch the rtc to bank 0.
+ * @rtc: pointer to the ds1685 rtc structure.
+ */
+static inline void
+ds1685_rtc_switch_to_bank0(struct ds1685_priv *rtc)
+{
+ rtc->write(rtc, RTC_CTRL_A,
+ (rtc->read(rtc, RTC_CTRL_A) & ~(RTC_CTRL_A_DV0)));
+}
+
+/**
+ * ds1685_rtc_switch_to_bank1 - switch the rtc to bank 1.
+ * @rtc: pointer to the ds1685 rtc structure.
+ */
+static inline void
+ds1685_rtc_switch_to_bank1(struct ds1685_priv *rtc)
+{
+ rtc->write(rtc, RTC_CTRL_A,
+ (rtc->read(rtc, RTC_CTRL_A) | RTC_CTRL_A_DV0));
+}
+
+/**
+ * ds1685_rtc_begin_data_access - prepare the rtc for data access.
+ * @rtc: pointer to the ds1685 rtc structure.
+ *
+ * This takes several steps to prepare the rtc for access to get/set time
+ * and alarm values from the rtc registers:
+ * - Sets the SET bit in Control Register B.
+ * - Reads Ext Control Register 4A and checks the INCR bit.
+ * - If INCR is active, a short delay is added before Ext Control Register 4A
+ * is read again in a loop until INCR is inactive.
+ * - Switches the rtc to bank 1. This allows access to all relevant
+ * data for normal rtc operation, as bank 0 contains only the nvram.
+ */
+static inline void
+ds1685_rtc_begin_data_access(struct ds1685_priv *rtc)
+{
+ /* Set the SET bit in Ctrl B */
+ rtc->write(rtc, RTC_CTRL_B,
+ (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
+
+ /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
+ while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
+ cpu_relax();
+
+ /* Switch to Bank 1 */
+ ds1685_rtc_switch_to_bank1(rtc);
+}
+
+/**
+ * ds1685_rtc_end_data_access - end data access on the rtc.
+ * @rtc: pointer to the ds1685 rtc structure.
+ *
+ * This ends what was started by ds1685_rtc_begin_data_access:
+ * - Switches the rtc back to bank 0.
+ * - Clears the SET bit in Control Register B.
+ */
+static inline void
+ds1685_rtc_end_data_access(struct ds1685_priv *rtc)
+{
+ /* Switch back to Bank 0 */
+ ds1685_rtc_switch_to_bank1(rtc);
+
+ /* Clear the SET bit in Ctrl B */
+ rtc->write(rtc, RTC_CTRL_B,
+ (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
+}
+
+/**
+ * ds1685_rtc_begin_ctrl_access - prepare the rtc for ctrl access.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @flags: irq flags variable for spin_lock_irqsave.
+ *
+ * This takes several steps to prepare the rtc for access to read just the
+ * control registers:
+ * - Sets a spinlock on the rtc IRQ.
+ * - Switches the rtc to bank 1. This allows access to the two extended
+ * control registers.
+ *
+ * Only use this where you are certain another lock will not be held.
+ */
+static inline void
+ds1685_rtc_begin_ctrl_access(struct ds1685_priv *rtc, unsigned long flags)
+{
+ spin_lock_irqsave(&rtc->lock, flags);
+ ds1685_rtc_switch_to_bank1(rtc);
+}
+
+/**
+ * ds1685_rtc_end_ctrl_access - end ctrl access on the rtc.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @flags: irq flags variable for spin_unlock_irqrestore.
+ *
+ * This ends what was started by ds1685_rtc_begin_ctrl_access:
+ * - Switches the rtc back to bank 0.
+ * - Unsets the spinlock on the rtc IRQ.
+ */
+static inline void
+ds1685_rtc_end_ctrl_access(struct ds1685_priv *rtc, unsigned long flags)
+{
+ ds1685_rtc_switch_to_bank0(rtc);
+ spin_unlock_irqrestore(&rtc->lock, flags);
+}
+
+/**
+ * ds1685_rtc_get_ssn - retrieve the silicon serial number.
+ * @rtc: pointer to the ds1685 rtc structure.
+ * @ssn: u8 array to hold the bits of the silicon serial number.
+ *
+ * This number starts at 0x40, and is 8-bytes long, ending at 0x47. The
+ * first byte is the model number, the next six bytes are the serial number
+ * digits, and the final byte is a CRC check byte. Together, they form the
+ * silicon serial number.
+ *
+ * These values are stored in bank1, so ds1685_rtc_switch_to_bank1 must be
+ * called first before calling this function, else data will be read out of
+ * the bank0 NVRAM. Be sure to call ds1685_rtc_switch_to_bank0 when done.
+ */
+static inline void
+ds1685_rtc_get_ssn(struct ds1685_priv *rtc, u8 *ssn)
+{
+ ssn[0] = rtc->read(rtc, RTC_BANK1_SSN_MODEL);
+ ssn[1] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_1);
+ ssn[2] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_2);
+ ssn[3] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_3);
+ ssn[4] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_4);
+ ssn[5] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_5);
+ ssn[6] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_6);
+ ssn[7] = rtc->read(rtc, RTC_BANK1_SSN_CRC);
+}
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* Read/Set Time & Alarm functions */
+
+/**
+ * ds1685_rtc_read_time - reads the time registers.
+ * @dev: pointer to device structure.
+ * @tm: pointer to rtc_time structure.
+ */
+static int
+ds1685_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrlb, century;
+ u8 seconds, minutes, hours, wday, mday, month, years;
+
+ /* Fetch the time info from the RTC registers. */
+ ds1685_rtc_begin_data_access(rtc);
+ seconds = rtc->read(rtc, RTC_SECS);
+ minutes = rtc->read(rtc, RTC_MINS);
+ hours = rtc->read(rtc, RTC_HRS);
+ wday = rtc->read(rtc, RTC_WDAY);
+ mday = rtc->read(rtc, RTC_MDAY);
+ month = rtc->read(rtc, RTC_MONTH);
+ years = rtc->read(rtc, RTC_YEAR);
+ century = rtc->read(rtc, RTC_CENTURY);
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ ds1685_rtc_end_data_access(rtc);
+
+ /* bcd2bin if needed, perform fixups, and store to rtc_time. */
+ years = ds1685_rtc_bcd2bin(rtc, years, RTC_YEAR_BCD_MASK,
+ RTC_YEAR_BIN_MASK);
+ century = ds1685_rtc_bcd2bin(rtc, century, RTC_CENTURY_MASK,
+ RTC_CENTURY_MASK);
+ tm->tm_sec = ds1685_rtc_bcd2bin(rtc, seconds, RTC_SECS_BCD_MASK,
+ RTC_SECS_BIN_MASK);
+ tm->tm_min = ds1685_rtc_bcd2bin(rtc, minutes, RTC_MINS_BCD_MASK,
+ RTC_MINS_BIN_MASK);
+ tm->tm_hour = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_24_BCD_MASK,
+ RTC_HRS_24_BIN_MASK);
+ tm->tm_wday = (ds1685_rtc_bcd2bin(rtc, wday, RTC_WDAY_MASK,
+ RTC_WDAY_MASK) - 1);
+ tm->tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
+ RTC_MDAY_BIN_MASK);
+ tm->tm_mon = (ds1685_rtc_bcd2bin(rtc, month, RTC_MONTH_BCD_MASK,
+ RTC_MONTH_BIN_MASK) - 1);
+ tm->tm_year = ((years + (century * 100)) - 1900);
+ tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+ tm->tm_isdst = 0; /* RTC has hardcoded timezone, so don't use. */
+
+ return rtc_valid_tm(tm);
+}
+
+/**
+ * ds1685_rtc_set_time - sets the time registers.
+ * @dev: pointer to device structure.
+ * @tm: pointer to rtc_time structure.
+ */
+static int
+ds1685_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrlb, seconds, minutes, hours, wday, mday, month, years, century;
+
+ /* Fetch the time info from rtc_time. */
+ seconds = ds1685_rtc_bin2bcd(rtc, tm->tm_sec, RTC_SECS_BIN_MASK,
+ RTC_SECS_BCD_MASK);
+ minutes = ds1685_rtc_bin2bcd(rtc, tm->tm_min, RTC_MINS_BIN_MASK,
+ RTC_MINS_BCD_MASK);
+ hours = ds1685_rtc_bin2bcd(rtc, tm->tm_hour, RTC_HRS_24_BIN_MASK,
+ RTC_HRS_24_BCD_MASK);
+ wday = ds1685_rtc_bin2bcd(rtc, (tm->tm_wday + 1), RTC_WDAY_MASK,
+ RTC_WDAY_MASK);
+ mday = ds1685_rtc_bin2bcd(rtc, tm->tm_mday, RTC_MDAY_BIN_MASK,
+ RTC_MDAY_BCD_MASK);
+ month = ds1685_rtc_bin2bcd(rtc, (tm->tm_mon + 1), RTC_MONTH_BIN_MASK,
+ RTC_MONTH_BCD_MASK);
+ years = ds1685_rtc_bin2bcd(rtc, (tm->tm_year % 100),
+ RTC_YEAR_BIN_MASK, RTC_YEAR_BCD_MASK);
+ century = ds1685_rtc_bin2bcd(rtc, ((tm->tm_year + 1900) / 100),
+ RTC_CENTURY_MASK, RTC_CENTURY_MASK);
+
+ /*
+ * Perform Sanity Checks:
+ * - Months: !> 12, Month Day != 0.
+ * - Month Day !> Max days in current month.
+ * - Hours !>= 24, Mins !>= 60, Secs !>= 60, & Weekday !> 7.
+ */
+ if ((tm->tm_mon > 11) || (mday == 0))
+ return -EDOM;
+
+ if (tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year))
+ return -EDOM;
+
+ if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) ||
+ (tm->tm_sec >= 60) || (wday > 7))
+ return -EDOM;
+
+ /*
+ * Set the data mode to use and store the time values in the
+ * RTC registers.
+ */
+ ds1685_rtc_begin_data_access(rtc);
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ if (rtc->bcd_mode)
+ ctrlb &= ~(RTC_CTRL_B_DM);
+ else
+ ctrlb |= RTC_CTRL_B_DM;
+ rtc->write(rtc, RTC_CTRL_B, ctrlb);
+ rtc->write(rtc, RTC_SECS, seconds);
+ rtc->write(rtc, RTC_MINS, minutes);
+ rtc->write(rtc, RTC_HRS, hours);
+ rtc->write(rtc, RTC_WDAY, wday);
+ rtc->write(rtc, RTC_MDAY, mday);
+ rtc->write(rtc, RTC_MONTH, month);
+ rtc->write(rtc, RTC_YEAR, years);
+ rtc->write(rtc, RTC_CENTURY, century);
+ ds1685_rtc_end_data_access(rtc);
+
+ return 0;
+}
+
+/**
+ * ds1685_rtc_read_alarm - reads the alarm registers.
+ * @dev: pointer to device structure.
+ * @alrm: pointer to rtc_wkalrm structure.
+ *
+ * There are three primary alarm registers: seconds, minutes, and hours.
+ * A fourth alarm register for the month date is also available in bank1 for
+ * kickstart/wakeup features. The DS1685/DS1687 manual states that a
+ * "don't care" value ranging from 0xc0 to 0xff may be written into one or
+ * more of the three alarm bytes to act as a wildcard value. The fourth
+ * byte doesn't support a "don't care" value.
+ */
+static int
+ds1685_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 seconds, minutes, hours, mday, ctrlb, ctrlc;
+
+ /* Fetch the alarm info from the RTC alarm registers. */
+ ds1685_rtc_begin_data_access(rtc);
+ seconds = rtc->read(rtc, RTC_SECS_ALARM);
+ minutes = rtc->read(rtc, RTC_MINS_ALARM);
+ hours = rtc->read(rtc, RTC_HRS_ALARM);
+ mday = rtc->read(rtc, RTC_MDAY_ALARM);
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ ctrlc = rtc->read(rtc, RTC_CTRL_C);
+ ds1685_rtc_end_data_access(rtc);
+
+ /* Check month date. */
+ if (!(mday >= 1) && (mday <= 31))
+ return -EDOM;
+
+ /*
+ * Check the three alarm bytes.
+ *
+ * The Linux RTC system doesn't support the "don't care" capability
+ * of this RTC chip. We check for it anyways in case support is
+ * added in the future.
+ */
+ if (unlikely((seconds >= 0xc0) && (seconds <= 0xff)))
+ alrm->time.tm_sec = -1;
+ else
+ alrm->time.tm_sec = ds1685_rtc_bcd2bin(rtc, seconds,
+ RTC_SECS_BCD_MASK,
+ RTC_SECS_BIN_MASK);
+
+ if (unlikely((minutes >= 0xc0) && (minutes <= 0xff)))
+ alrm->time.tm_min = -1;
+ else
+ alrm->time.tm_min = ds1685_rtc_bcd2bin(rtc, minutes,
+ RTC_MINS_BCD_MASK,
+ RTC_MINS_BIN_MASK);
+
+ if (unlikely((hours >= 0xc0) && (hours <= 0xff)))
+ alrm->time.tm_hour = -1;
+ else
+ alrm->time.tm_hour = ds1685_rtc_bcd2bin(rtc, hours,
+ RTC_HRS_24_BCD_MASK,
+ RTC_HRS_24_BIN_MASK);
+
+ /* Write the data to rtc_wkalrm. */
+ alrm->time.tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
+ RTC_MDAY_BIN_MASK);
+ alrm->time.tm_mon = -1;
+ alrm->time.tm_year = -1;
+ alrm->time.tm_wday = -1;
+ alrm->time.tm_yday = -1;
+ alrm->time.tm_isdst = -1;
+ alrm->enabled = !!(ctrlb & RTC_CTRL_B_AIE);
+ alrm->pending = !!(ctrlc & RTC_CTRL_C_AF);
+
+ return 0;
+}
+
+/**
+ * ds1685_rtc_set_alarm - sets the alarm in registers.
+ * @dev: pointer to device structure.
+ * @alrm: pointer to rtc_wkalrm structure.
+ */
+static int
+ds1685_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrlb, seconds, minutes, hours, mday;
+
+ /* Fetch the alarm info and convert to BCD. */
+ seconds = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_sec,
+ RTC_SECS_BIN_MASK,
+ RTC_SECS_BCD_MASK);
+ minutes = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_min,
+ RTC_MINS_BIN_MASK,
+ RTC_MINS_BCD_MASK);
+ hours = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_hour,
+ RTC_HRS_24_BIN_MASK,
+ RTC_HRS_24_BCD_MASK);
+ mday = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_mday,
+ RTC_MDAY_BIN_MASK,
+ RTC_MDAY_BCD_MASK);
+
+ /* Check the month date for validity. */
+ if (!(mday >= 1) && (mday <= 31))
+ return -EDOM;
+
+ /*
+ * Check the three alarm bytes.
+ *
+ * The Linux RTC system doesn't support the "don't care" capability
+ * of this RTC chip because rtc_valid_tm tries to validate every
+ * field, and we only support four fields. We put the support
+ * here anyways for the future.
+ */
+ if (unlikely((seconds >= 0xc0) && (seconds <= 0xff)))
+ seconds = 0xff;
+
+ if (unlikely((minutes >= 0xc0) && (minutes <= 0xff)))
+ minutes = 0xff;
+
+ if (unlikely((hours >= 0xc0) && (hours <= 0xff)))
+ hours = 0xff;
+
+ alrm->time.tm_mon = -1;
+ alrm->time.tm_year = -1;
+ alrm->time.tm_wday = -1;
+ alrm->time.tm_yday = -1;
+ alrm->time.tm_isdst = -1;
+
+ /* Disable the alarm interrupt first. */
+ ds1685_rtc_begin_data_access(rtc);
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ rtc->write(rtc, RTC_CTRL_B, (ctrlb & ~(RTC_CTRL_B_AIE)));
+
+ /* Read ctrlc to clear RTC_CTRL_C_AF. */
+ rtc->read(rtc, RTC_CTRL_C);
+
+ /*
+ * Set the data mode to use and store the time values in the
+ * RTC registers.
+ */
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ if (rtc->bcd_mode)
+ ctrlb &= ~(RTC_CTRL_B_DM);
+ else
+ ctrlb |= RTC_CTRL_B_DM;
+ rtc->write(rtc, RTC_CTRL_B, ctrlb);
+ rtc->write(rtc, RTC_SECS_ALARM, seconds);
+ rtc->write(rtc, RTC_MINS_ALARM, minutes);
+ rtc->write(rtc, RTC_HRS_ALARM, hours);
+ rtc->write(rtc, RTC_MDAY_ALARM, mday);
+
+ /* Re-enable the alarm if needed. */
+ if (alrm->enabled) {
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ ctrlb |= RTC_CTRL_B_AIE;
+ rtc->write(rtc, RTC_CTRL_B, ctrlb);
+ }
+
+ /* Done! */
+ ds1685_rtc_end_data_access(rtc);
+
+ return 0;
+}
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* /dev/rtcX Interface functions */
+
+#ifdef CONFIG_RTC_INTF_DEV
+/**
+ * ds1685_rtc_alarm_irq_enable - replaces ioctl() RTC_AIE on/off.
+ * @dev: pointer to device structure.
+ * @enabled: flag indicating whether to enable or disable.
+ */
+static int
+ds1685_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct ds1685_priv *rtc = dev_get_drvdata(dev);
+ unsigned long flags = 0;
+
+ /* Enable/disable the Alarm IRQ-Enable flag. */
+ spin_lock_irqsave(&rtc->lock, flags);
+
+ /* Flip the requisite interrupt-enable bit. */
+ if (enabled)
+ rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) |
+ RTC_CTRL_B_AIE));
+ else
+ rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) &
+ ~(RTC_CTRL_B_AIE)));
+
+ /* Read Control C to clear all the flag bits. */
+ rtc->read(rtc, RTC_CTRL_C);
+ spin_unlock_irqrestore(&rtc->lock, flags);
+
+ return 0;
+}
+#endif
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* IRQ handler & workqueue. */
+
+/**
+ * ds1685_rtc_irq_handler - IRQ handler.
+ * @irq: IRQ number.
+ * @dev_id: platform device pointer.
+ */
+static irqreturn_t
+ds1685_rtc_irq_handler(int irq, void *dev_id)
+{
+ struct platform_device *pdev = dev_id;
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrlb, ctrlc;
+ unsigned long events = 0;
+ u8 num_irqs = 0;
+
+ /* Abort early if the device isn't ready yet (i.e., DEBUG_SHIRQ). */
+ if (unlikely(!rtc))
+ return IRQ_HANDLED;
+
+ /* Ctrlb holds the interrupt-enable bits and ctrlc the flag bits. */
+ spin_lock(&rtc->lock);
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ ctrlc = rtc->read(rtc, RTC_CTRL_C);
+
+ /* Is the IRQF bit set? */
+ if (likely(ctrlc & RTC_CTRL_C_IRQF)) {
+ /*
+ * We need to determine if it was one of the standard
+ * events: PF, AF, or UF. If so, we handle them and
+ * update the RTC core.
+ */
+ if (likely(ctrlc & RTC_CTRL_B_PAU_MASK)) {
+ events = RTC_IRQF;
+
+ /* Check for a periodic interrupt. */
+ if ((ctrlb & RTC_CTRL_B_PIE) &&
+ (ctrlc & RTC_CTRL_C_PF)) {
+ events |= RTC_PF;
+ num_irqs++;
+ }
+
+ /* Check for an alarm interrupt. */
+ if ((ctrlb & RTC_CTRL_B_AIE) &&
+ (ctrlc & RTC_CTRL_C_AF)) {
+ events |= RTC_AF;
+ num_irqs++;
+ }
+
+ /* Check for an update interrupt. */
+ if ((ctrlb & RTC_CTRL_B_UIE) &&
+ (ctrlc & RTC_CTRL_C_UF)) {
+ events |= RTC_UF;
+ num_irqs++;
+ }
+
+ rtc_update_irq(rtc->dev, num_irqs, events);
+ } else {
+ /*
+ * One of the "extended" interrupts was received that
+ * is not recognized by the RTC core. These need to
+ * be handled in task context as they can call other
+ * functions and the time spent in irq context needs
+ * to be minimized. Schedule them into a workqueue
+ * and inform the RTC core that the IRQs were handled.
+ */
+ spin_unlock(&rtc->lock);
+ schedule_work(&rtc->work);
+ rtc_update_irq(rtc->dev, 0, 0);
+ return IRQ_HANDLED;
+ }
+ }
+ spin_unlock(&rtc->lock);
+
+ return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+/**
+ * ds1685_rtc_work_queue - work queue handler.
+ * @work: work_struct containing data to work on in task context.
+ */
+static void
+ds1685_rtc_work_queue(struct work_struct *work)
+{
+ struct ds1685_priv *rtc = container_of(work,
+ struct ds1685_priv, work);
+ struct platform_device *pdev = to_platform_device(&rtc->dev->dev);
+ struct mutex *rtc_mutex = &rtc->dev->ops_lock;
+ u8 ctrl4a, ctrl4b;
+
+ mutex_lock(rtc_mutex);
+
+ ds1685_rtc_switch_to_bank1(rtc);
+ ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
+ ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
+
+ /*
+ * Check for a kickstart interrupt. With Vcc applied, this
+ * typically means that the power button was pressed, so we
+ * begin the shutdown sequence.
+ */
+ if ((ctrl4b & RTC_CTRL_4B_KSE) && (ctrl4a & RTC_CTRL_4A_KF)) {
+ /* Briefly disable kickstarts to debounce button presses. */
+ rtc->write(rtc, RTC_EXT_CTRL_4B,
+ (rtc->read(rtc, RTC_EXT_CTRL_4B) &
+ ~(RTC_CTRL_4B_KSE)));
+
+ /* Clear the kickstart flag. */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (ctrl4a & ~(RTC_CTRL_4A_KF)));
+
+
+ /*
+ * Sleep 500ms before re-enabling kickstarts. This allows
+ * adequate time to avoid reading signal jitter as additional
+ * button presses.
+ */
+ msleep(500);
+ rtc->write(rtc, RTC_EXT_CTRL_4B,
+ (rtc->read(rtc, RTC_EXT_CTRL_4B) |
+ RTC_CTRL_4B_KSE));
+
+ /* Call the platform pre-poweroff function. Else, shutdown. */
+ if (rtc->prepare_poweroff != NULL)
+ rtc->prepare_poweroff();
+ else
+ ds1685_rtc_poweroff(pdev);
+ }
+
+ /*
+ * Check for a wake-up interrupt. With Vcc applied, this is
+ * essentially a second alarm interrupt, except it takes into
+ * account the 'date' register in bank1 in addition to the
+ * standard three alarm registers.
+ */
+ if ((ctrl4b & RTC_CTRL_4B_WIE) && (ctrl4a & RTC_CTRL_4A_WF)) {
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (ctrl4a & ~(RTC_CTRL_4A_WF)));
+
+ /* Call the platform wake_alarm function if defined. */
+ if (rtc->wake_alarm != NULL)
+ rtc->wake_alarm();
+ else
+ dev_warn(&pdev->dev,
+ "Wake Alarm IRQ just occurred!\n");
+ }
+
+ /*
+ * Check for a ram-clear interrupt. This happens if RIE=1 and RF=0
+ * when RCE=1 in 4B. This clears all NVRAM bytes in bank0 by setting
+ * each byte to a logic 1. This has no effect on any extended
+ * NV-SRAM that might be present, nor on the time/calendar/alarm
+ * registers. After a ram-clear is completed, there is a minimum
+ * recovery time of ~150ms in which all reads/writes are locked out.
+ * NOTE: A ram-clear can still occur if RCE=1 and RIE=0. We cannot
+ * catch this scenario.
+ */
+ if ((ctrl4b & RTC_CTRL_4B_RIE) && (ctrl4a & RTC_CTRL_4A_RF)) {
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (ctrl4a & ~(RTC_CTRL_4A_RF)));
+ msleep(150);
+
+ /* Call the platform post_ram_clear function if defined. */
+ if (rtc->post_ram_clear != NULL)
+ rtc->post_ram_clear();
+ else
+ dev_warn(&pdev->dev,
+ "RAM-Clear IRQ just occurred!\n");
+ }
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ mutex_unlock(rtc_mutex);
+}
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* ProcFS interface */
+
+#ifdef CONFIG_PROC_FS
+#define NUM_REGS 6 /* Num of control registers. */
+#define NUM_BITS 8 /* Num bits per register. */
+#define NUM_SPACES 4 /* Num spaces between each bit. */
+
+/*
+ * Periodic Interrupt Rates.
+ */
+static const char *ds1685_rtc_pirq_rate[16] = {
+ "none", "3.90625ms", "7.8125ms", "0.122070ms", "0.244141ms",
+ "0.488281ms", "0.9765625ms", "1.953125ms", "3.90625ms", "7.8125ms",
+ "15.625ms", "31.25ms", "62.5ms", "125ms", "250ms", "500ms"
+};
+
+/*
+ * Square-Wave Output Frequencies.
+ */
+static const char *ds1685_rtc_sqw_freq[16] = {
+ "none", "256Hz", "128Hz", "8192Hz", "4096Hz", "2048Hz", "1024Hz",
+ "512Hz", "256Hz", "128Hz", "64Hz", "32Hz", "16Hz", "8Hz", "4Hz", "2Hz"
+};
+
+#ifdef CONFIG_RTC_DS1685_PROC_REGS
+/**
+ * ds1685_rtc_print_regs - helper function to print register values.
+ * @hex: hex byte to convert into binary bits.
+ * @dest: destination char array.
+ *
+ * This is basically a hex->binary function, just with extra spacing between
+ * the digits. It only works on 1-byte values (8 bits).
+ */
+static char*
+ds1685_rtc_print_regs(u8 hex, char *dest)
+{
+ u32 i, j;
+ char *tmp = dest;
+
+ for (i = 0; i < NUM_BITS; i++) {
+ *tmp++ = ((hex & 0x80) != 0 ? '1' : '0');
+ for (j = 0; j < NUM_SPACES; j++)
+ *tmp++ = ' ';
+ hex <<= 1;
+ }
+ *tmp++ = '\0';
+
+ return dest;
+}
+#endif
+
+/**
+ * ds1685_rtc_proc - procfs access function.
+ * @dev: pointer to device structure.
+ * @seq: pointer to seq_file structure.
+ */
+static int
+ds1685_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrla, ctrlb, ctrlc, ctrld, ctrl4a, ctrl4b, ssn[8];
+ char *model = '\0';
+#ifdef CONFIG_RTC_DS1685_PROC_REGS
+ char bits[NUM_REGS][(NUM_BITS * NUM_SPACES) + NUM_BITS + 1];
+#endif
+
+ /* Read all the relevant data from the control registers. */
+ ds1685_rtc_switch_to_bank1(rtc);
+ ds1685_rtc_get_ssn(rtc, ssn);
+ ctrla = rtc->read(rtc, RTC_CTRL_A);
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ ctrlc = rtc->read(rtc, RTC_CTRL_C);
+ ctrld = rtc->read(rtc, RTC_CTRL_D);
+ ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
+ ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ /* Determine the RTC model. */
+ switch (ssn[0]) {
+ case RTC_MODEL_DS1685:
+ model = "DS1685/DS1687\0";
+ break;
+ case RTC_MODEL_DS1689:
+ model = "DS1689/DS1693\0";
+ break;
+ case RTC_MODEL_DS17285:
+ model = "DS17285/DS17287\0";
+ break;
+ case RTC_MODEL_DS17485:
+ model = "DS17485/DS17487\0";
+ break;
+ case RTC_MODEL_DS17885:
+ model = "DS17885/DS17887\0";
+ break;
+ default:
+ model = "Unknown\0";
+ break;
+ }
+
+ /* Print out the information. */
+ seq_printf(seq,
+ "Model\t\t: %s\n"
+ "Oscillator\t: %s\n"
+ "12/24hr\t\t: %s\n"
+ "DST\t\t: %s\n"
+ "Data mode\t: %s\n"
+ "Battery\t\t: %s\n"
+ "Aux batt\t: %s\n"
+ "Update IRQ\t: %s\n"
+ "Periodic IRQ\t: %s\n"
+ "Periodic Rate\t: %s\n"
+ "SQW Freq\t: %s\n"
+#ifdef CONFIG_RTC_DS1685_PROC_REGS
+ "Serial #\t: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n"
+ "Register Status\t:\n"
+ " Ctrl A\t: UIP DV2 DV1 DV0 RS3 RS2 RS1 RS0\n"
+ "\t\t: %s\n"
+ " Ctrl B\t: SET PIE AIE UIE SQWE DM 2412 DSE\n"
+ "\t\t: %s\n"
+ " Ctrl C\t: IRQF PF AF UF --- --- --- ---\n"
+ "\t\t: %s\n"
+ " Ctrl D\t: VRT --- --- --- --- --- --- ---\n"
+ "\t\t: %s\n"
+#if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
+ " Ctrl 4A\t: VRT2 INCR BME --- PAB RF WF KF\n"
+#else
+ " Ctrl 4A\t: VRT2 INCR --- --- PAB RF WF KF\n"
+#endif
+ "\t\t: %s\n"
+ " Ctrl 4B\t: ABE E32k CS RCE PRS RIE WIE KSE\n"
+ "\t\t: %s\n",
+#else
+ "Serial #\t: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+#endif
+ model,
+ ((ctrla & RTC_CTRL_A_DV1) ? "enabled" : "disabled"),
+ ((ctrlb & RTC_CTRL_B_2412) ? "24-hour" : "12-hour"),
+ ((ctrlb & RTC_CTRL_B_DSE) ? "enabled" : "disabled"),
+ ((ctrlb & RTC_CTRL_B_DM) ? "binary" : "BCD"),
+ ((ctrld & RTC_CTRL_D_VRT) ? "ok" : "exhausted or n/a"),
+ ((ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "exhausted or n/a"),
+ ((ctrlb & RTC_CTRL_B_UIE) ? "yes" : "no"),
+ ((ctrlb & RTC_CTRL_B_PIE) ? "yes" : "no"),
+ (!(ctrl4b & RTC_CTRL_4B_E32K) ?
+ ds1685_rtc_pirq_rate[(ctrla & RTC_CTRL_A_RS_MASK)] : "none"),
+ (!((ctrl4b & RTC_CTRL_4B_E32K)) ?
+ ds1685_rtc_sqw_freq[(ctrla & RTC_CTRL_A_RS_MASK)] : "32768Hz"),
+#ifdef CONFIG_RTC_DS1685_PROC_REGS
+ ssn[0], ssn[1], ssn[2], ssn[3], ssn[4], ssn[5], ssn[6], ssn[7],
+ ds1685_rtc_print_regs(ctrla, bits[0]),
+ ds1685_rtc_print_regs(ctrlb, bits[1]),
+ ds1685_rtc_print_regs(ctrlc, bits[2]),
+ ds1685_rtc_print_regs(ctrld, bits[3]),
+ ds1685_rtc_print_regs(ctrl4a, bits[4]),
+ ds1685_rtc_print_regs(ctrl4b, bits[5]));
+#else
+ ssn[0], ssn[1], ssn[2], ssn[3], ssn[4], ssn[5], ssn[6], ssn[7]);
+#endif
+ return 0;
+}
+#else
+#define ds1685_rtc_proc NULL
+#endif /* CONFIG_PROC_FS */
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* RTC Class operations */
+
+static const struct rtc_class_ops
+ds1685_rtc_ops = {
+ .proc = ds1685_rtc_proc,
+ .read_time = ds1685_rtc_read_time,
+ .set_time = ds1685_rtc_set_time,
+ .read_alarm = ds1685_rtc_read_alarm,
+ .set_alarm = ds1685_rtc_set_alarm,
+ .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,
+};
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* SysFS interface */
+
+#ifdef CONFIG_SYSFS
+/**
+ * ds1685_rtc_sysfs_nvram_read - reads rtc nvram via sysfs.
+ * @file: pointer to file structure.
+ * @kobj: pointer to kobject structure.
+ * @bin_attr: pointer to bin_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ * @pos: current file position pointer.
+ * @size: size of the data to read.
+ */
+static ssize_t
+ds1685_rtc_sysfs_nvram_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t pos, size_t size)
+{
+ struct platform_device *pdev =
+ to_platform_device(container_of(kobj, struct device, kobj));
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ ssize_t count;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&rtc->lock, flags);
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ /* Read NVRAM in time and bank0 registers. */
+ for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
+ count++, size--) {
+ if (count < NVRAM_SZ_TIME)
+ *buf++ = rtc->read(rtc, (NVRAM_TIME_BASE + pos++));
+ else
+ *buf++ = rtc->read(rtc, (NVRAM_BANK0_BASE + pos++));
+ }
+
+#ifndef CONFIG_RTC_DRV_DS1689
+ if (size > 0) {
+ ds1685_rtc_switch_to_bank1(rtc);
+
+#ifndef CONFIG_RTC_DRV_DS1685
+ /* Enable burst-mode on DS17x85/DS17x87 */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (rtc->read(rtc, RTC_EXT_CTRL_4A) |
+ RTC_CTRL_4A_BME));
+
+ /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
+ * reading with burst-mode */
+ rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
+ (pos - NVRAM_TOTAL_SZ_BANK0));
+#endif
+
+ /* Read NVRAM in bank1 registers. */
+ for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
+ count++, size--) {
+#ifdef CONFIG_RTC_DRV_DS1685
+ /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
+ * before each read. */
+ rtc->write(rtc, RTC_BANK1_RAM_ADDR,
+ (pos - NVRAM_TOTAL_SZ_BANK0));
+#endif
+ *buf++ = rtc->read(rtc, RTC_BANK1_RAM_DATA_PORT);
+ pos++;
+ }
+
+#ifndef CONFIG_RTC_DRV_DS1685
+ /* Disable burst-mode on DS17x85/DS17x87 */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (rtc->read(rtc, RTC_EXT_CTRL_4A) &
+ ~(RTC_CTRL_4A_BME)));
+#endif
+ ds1685_rtc_switch_to_bank0(rtc);
+ }
+#endif /* !CONFIG_RTC_DRV_DS1689 */
+ spin_unlock_irqrestore(&rtc->lock, flags);
+
+ /*
+ * XXX: Bug? this appears to cause the function to get executed
+ * several times in succession. But it's the only way to actually get
+ * data written out to a file.
+ */
+ return count;
+}
+
+/**
+ * ds1685_rtc_sysfs_nvram_write - writes rtc nvram via sysfs.
+ * @file: pointer to file structure.
+ * @kobj: pointer to kobject structure.
+ * @bin_attr: pointer to bin_attribute structure.
+ * @buf: pointer to char array to hold the input.
+ * @pos: current file position pointer.
+ * @size: size of the data to write.
+ */
+static ssize_t
+ds1685_rtc_sysfs_nvram_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t pos, size_t size)
+{
+ struct platform_device *pdev =
+ to_platform_device(container_of(kobj, struct device, kobj));
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ ssize_t count;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&rtc->lock, flags);
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ /* Write NVRAM in time and bank0 registers. */
+ for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
+ count++, size--)
+ if (count < NVRAM_SZ_TIME)
+ rtc->write(rtc, (NVRAM_TIME_BASE + pos++),
+ *buf++);
+ else
+ rtc->write(rtc, (NVRAM_BANK0_BASE), *buf++);
+
+#ifndef CONFIG_RTC_DRV_DS1689
+ if (size > 0) {
+ ds1685_rtc_switch_to_bank1(rtc);
+
+#ifndef CONFIG_RTC_DRV_DS1685
+ /* Enable burst-mode on DS17x85/DS17x87 */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (rtc->read(rtc, RTC_EXT_CTRL_4A) |
+ RTC_CTRL_4A_BME));
+
+ /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
+ * writing with burst-mode */
+ rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
+ (pos - NVRAM_TOTAL_SZ_BANK0));
+#endif
+
+ /* Write NVRAM in bank1 registers. */
+ for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
+ count++, size--) {
+#ifdef CONFIG_RTC_DRV_DS1685
+ /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
+ * before each read. */
+ rtc->write(rtc, RTC_BANK1_RAM_ADDR,
+ (pos - NVRAM_TOTAL_SZ_BANK0));
+#endif
+ rtc->write(rtc, RTC_BANK1_RAM_DATA_PORT, *buf++);
+ pos++;
+ }
+
+#ifndef CONFIG_RTC_DRV_DS1685
+ /* Disable burst-mode on DS17x85/DS17x87 */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (rtc->read(rtc, RTC_EXT_CTRL_4A) &
+ ~(RTC_CTRL_4A_BME)));
+#endif
+ ds1685_rtc_switch_to_bank0(rtc);
+ }
+#endif /* !CONFIG_RTC_DRV_DS1689 */
+ spin_unlock_irqrestore(&rtc->lock, flags);
+
+ return count;
+}
+
+/**
+ * struct ds1685_rtc_sysfs_nvram_attr - sysfs attributes for rtc nvram.
+ * @attr: nvram attributes.
+ * @read: nvram read function.
+ * @write: nvram write function.
+ * @size: nvram total size (bank0 + extended).
+ */
+static struct bin_attribute
+ds1685_rtc_sysfs_nvram_attr = {
+ .attr = {
+ .name = "nvram",
+ .mode = S_IRUGO | S_IWUSR,
+ },
+ .read = ds1685_rtc_sysfs_nvram_read,
+ .write = ds1685_rtc_sysfs_nvram_write,
+ .size = NVRAM_TOTAL_SZ
+};
+
+/**
+ * ds1685_rtc_sysfs_battery_show - sysfs file for main battery status.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ */
+static ssize_t
+ds1685_rtc_sysfs_battery_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrld;
+
+ ctrld = rtc->read(rtc, RTC_CTRL_D);
+
+ return snprintf(buf, 13, "%s\n",
+ (ctrld & RTC_CTRL_D_VRT) ? "ok" : "not ok or N/A");
+}
+static DEVICE_ATTR(battery, S_IRUGO, ds1685_rtc_sysfs_battery_show, NULL);
+
+/**
+ * ds1685_rtc_sysfs_auxbatt_show - sysfs file for aux battery status.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ */
+static ssize_t
+ds1685_rtc_sysfs_auxbatt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ctrl4a;
+
+ ds1685_rtc_switch_to_bank1(rtc);
+ ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ return snprintf(buf, 13, "%s\n",
+ (ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "not ok or N/A");
+}
+static DEVICE_ATTR(auxbatt, S_IRUGO, ds1685_rtc_sysfs_auxbatt_show, NULL);
+
+/**
+ * ds1685_rtc_sysfs_serial_show - sysfs file for silicon serial number.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ */
+static ssize_t
+ds1685_rtc_sysfs_serial_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+ u8 ssn[8];
+
+ ds1685_rtc_switch_to_bank1(rtc);
+ ds1685_rtc_get_ssn(rtc, ssn);
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ return snprintf(buf, 24, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+ ssn[0], ssn[1], ssn[2], ssn[3], ssn[4], ssn[5],
+ ssn[6], ssn[7]);
+
+ return 0;
+}
+static DEVICE_ATTR(serial, S_IRUGO, ds1685_rtc_sysfs_serial_show, NULL);
+
+/**
+ * struct ds1685_rtc_sysfs_misc_attrs - list for misc RTC features.
+ */
+static struct attribute*
+ds1685_rtc_sysfs_misc_attrs[] = {
+ &dev_attr_battery.attr,
+ &dev_attr_auxbatt.attr,
+ &dev_attr_serial.attr,
+ NULL,
+};
+
+/**
+ * struct ds1685_rtc_sysfs_misc_grp - attr group for misc RTC features.
+ */
+static const struct attribute_group
+ds1685_rtc_sysfs_misc_grp = {
+ .name = "misc",
+ .attrs = ds1685_rtc_sysfs_misc_attrs,
+};
+
+#ifdef CONFIG_RTC_DS1685_SYSFS_REGS
+/**
+ * struct ds1685_rtc_ctrl_regs.
+ * @name: char pointer for the bit name.
+ * @reg: control register the bit is in.
+ * @bit: the bit's offset in the register.
+ */
+struct ds1685_rtc_ctrl_regs {
+ const char *name;
+ const u8 reg;
+ const u8 bit;
+};
+
+/*
+ * Ctrl register bit lookup table.
+ */
+static const struct ds1685_rtc_ctrl_regs
+ds1685_ctrl_regs_table[] = {
+ { "uip", RTC_CTRL_A, RTC_CTRL_A_UIP },
+ { "dv2", RTC_CTRL_A, RTC_CTRL_A_DV2 },
+ { "dv1", RTC_CTRL_A, RTC_CTRL_A_DV1 },
+ { "dv0", RTC_CTRL_A, RTC_CTRL_A_DV0 },
+ { "rs3", RTC_CTRL_A, RTC_CTRL_A_RS3 },
+ { "rs2", RTC_CTRL_A, RTC_CTRL_A_RS2 },
+ { "rs1", RTC_CTRL_A, RTC_CTRL_A_RS1 },
+ { "rs0", RTC_CTRL_A, RTC_CTRL_A_RS0 },
+ { "set", RTC_CTRL_B, RTC_CTRL_B_SET },
+ { "pie", RTC_CTRL_B, RTC_CTRL_B_PIE },
+ { "aie", RTC_CTRL_B, RTC_CTRL_B_AIE },
+ { "uie", RTC_CTRL_B, RTC_CTRL_B_UIE },
+ { "sqwe", RTC_CTRL_B, RTC_CTRL_B_SQWE },
+ { "dm", RTC_CTRL_B, RTC_CTRL_B_DM },
+ { "2412", RTC_CTRL_B, RTC_CTRL_B_2412 },
+ { "dse", RTC_CTRL_B, RTC_CTRL_B_DSE },
+ { "irqf", RTC_CTRL_C, RTC_CTRL_C_IRQF },
+ { "pf", RTC_CTRL_C, RTC_CTRL_C_PF },
+ { "af", RTC_CTRL_C, RTC_CTRL_C_AF },
+ { "uf", RTC_CTRL_C, RTC_CTRL_C_UF },
+ { "vrt", RTC_CTRL_D, RTC_CTRL_D_VRT },
+ { "vrt2", RTC_EXT_CTRL_4A, RTC_CTRL_4A_VRT2 },
+ { "incr", RTC_EXT_CTRL_4A, RTC_CTRL_4A_INCR },
+ { "pab", RTC_EXT_CTRL_4A, RTC_CTRL_4A_PAB },
+ { "rf", RTC_EXT_CTRL_4A, RTC_CTRL_4A_RF },
+ { "wf", RTC_EXT_CTRL_4A, RTC_CTRL_4A_WF },
+ { "kf", RTC_EXT_CTRL_4A, RTC_CTRL_4A_KF },
+#if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
+ { "bme", RTC_EXT_CTRL_4A, RTC_CTRL_4A_BME },
+#endif
+ { "abe", RTC_EXT_CTRL_4B, RTC_CTRL_4B_ABE },
+ { "e32k", RTC_EXT_CTRL_4B, RTC_CTRL_4B_E32K },
+ { "cs", RTC_EXT_CTRL_4B, RTC_CTRL_4B_CS },
+ { "rce", RTC_EXT_CTRL_4B, RTC_CTRL_4B_RCE },
+ { "prs", RTC_EXT_CTRL_4B, RTC_CTRL_4B_PRS },
+ { "rie", RTC_EXT_CTRL_4B, RTC_CTRL_4B_RIE },
+ { "wie", RTC_EXT_CTRL_4B, RTC_CTRL_4B_WIE },
+ { "kse", RTC_EXT_CTRL_4B, RTC_CTRL_4B_KSE },
+ { NULL, 0, 0 },
+};
+
+/**
+ * ds1685_rtc_sysfs_ctrl_regs_lookup - ctrl register bit lookup function.
+ * @name: ctrl register bit to look up in ds1685_ctrl_regs_table.
+ */
+static const struct ds1685_rtc_ctrl_regs*
+ds1685_rtc_sysfs_ctrl_regs_lookup(const char *name)
+{
+ const struct ds1685_rtc_ctrl_regs *p = ds1685_ctrl_regs_table;
+
+ for (; p->name != NULL; ++p)
+ if (strcmp(p->name, name) == 0)
+ return p;
+
+ return NULL;
+}
+
+/**
+ * ds1685_rtc_sysfs_ctrl_regs_show - reads a ctrl register bit via sysfs.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ */
+static ssize_t
+ds1685_rtc_sysfs_ctrl_regs_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ u8 tmp;
+ struct ds1685_priv *rtc = dev_get_drvdata(dev);
+ const struct ds1685_rtc_ctrl_regs *reg_info =
+ ds1685_rtc_sysfs_ctrl_regs_lookup(attr->attr.name);
+
+ /* Make sure we actually matched something. */
+ if (!reg_info)
+ return -EINVAL;
+
+ /* No spinlock during a read -- mutex is already held. */
+ ds1685_rtc_switch_to_bank1(rtc);
+ tmp = rtc->read(rtc, reg_info->reg) & reg_info->bit;
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ return snprintf(buf, 2, "%d\n", (tmp ? 1 : 0));
+}
+
+/**
+ * ds1685_rtc_sysfs_ctrl_regs_store - writes a ctrl register bit via sysfs.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ * @count: number of bytes written.
+ */
+static ssize_t
+ds1685_rtc_sysfs_ctrl_regs_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ds1685_priv *rtc = dev_get_drvdata(dev);
+ u8 reg = 0, bit = 0, tmp;
+ unsigned long flags = 0;
+ long int val = 0;
+ const struct ds1685_rtc_ctrl_regs *reg_info =
+ ds1685_rtc_sysfs_ctrl_regs_lookup(attr->attr.name);
+
+ /* We only accept numbers. */
+ if (kstrtol(buf, 10, &val) < 0)
+ return -EINVAL;
+
+ /* bits are binary, 0 or 1 only. */
+ if ((val != 0) && (val != 1))
+ return -ERANGE;
+
+ /* Make sure we actually matched something. */
+ if (!reg_info)
+ return -EINVAL;
+
+ reg = reg_info->reg;
+ bit = reg_info->bit;
+
+ /* Safe to spinlock during a write. */
+ ds1685_rtc_begin_ctrl_access(rtc, flags);
+ tmp = rtc->read(rtc, reg);
+ rtc->write(rtc, reg, (val ? (tmp | bit) : (tmp & ~(bit))));
+ ds1685_rtc_end_ctrl_access(rtc, flags);
+
+ return count;
+}
+
+/**
+ * DS1685_RTC_SYSFS_CTRL_REG_RO - device_attribute for read-only register bit.
+ * @bit: bit to read.
+ */
+#define DS1685_RTC_SYSFS_CTRL_REG_RO(bit) \
+ static DEVICE_ATTR(bit, S_IRUGO, \
+ ds1685_rtc_sysfs_ctrl_regs_show, NULL)
+
+/**
+ * DS1685_RTC_SYSFS_CTRL_REG_RW - device_attribute for read-write register bit.
+ * @bit: bit to read or write.
+ */
+#define DS1685_RTC_SYSFS_CTRL_REG_RW(bit) \
+ static DEVICE_ATTR(bit, S_IRUGO | S_IWUSR, \
+ ds1685_rtc_sysfs_ctrl_regs_show, \
+ ds1685_rtc_sysfs_ctrl_regs_store)
+
+/*
+ * Control Register A bits.
+ */
+DS1685_RTC_SYSFS_CTRL_REG_RO(uip);
+DS1685_RTC_SYSFS_CTRL_REG_RW(dv2);
+DS1685_RTC_SYSFS_CTRL_REG_RW(dv1);
+DS1685_RTC_SYSFS_CTRL_REG_RO(dv0);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rs3);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rs2);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rs1);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rs0);
+
+static struct attribute*
+ds1685_rtc_sysfs_ctrla_attrs[] = {
+ &dev_attr_uip.attr,
+ &dev_attr_dv2.attr,
+ &dev_attr_dv1.attr,
+ &dev_attr_dv0.attr,
+ &dev_attr_rs3.attr,
+ &dev_attr_rs2.attr,
+ &dev_attr_rs1.attr,
+ &dev_attr_rs0.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_ctrla_grp = {
+ .name = "ctrla",
+ .attrs = ds1685_rtc_sysfs_ctrla_attrs,
+};
+
+
+/*
+ * Control Register B bits.
+ */
+DS1685_RTC_SYSFS_CTRL_REG_RO(set);
+DS1685_RTC_SYSFS_CTRL_REG_RW(pie);
+DS1685_RTC_SYSFS_CTRL_REG_RW(aie);
+DS1685_RTC_SYSFS_CTRL_REG_RW(uie);
+DS1685_RTC_SYSFS_CTRL_REG_RW(sqwe);
+DS1685_RTC_SYSFS_CTRL_REG_RO(dm);
+DS1685_RTC_SYSFS_CTRL_REG_RO(2412);
+DS1685_RTC_SYSFS_CTRL_REG_RO(dse);
+
+static struct attribute*
+ds1685_rtc_sysfs_ctrlb_attrs[] = {
+ &dev_attr_set.attr,
+ &dev_attr_pie.attr,
+ &dev_attr_aie.attr,
+ &dev_attr_uie.attr,
+ &dev_attr_sqwe.attr,
+ &dev_attr_dm.attr,
+ &dev_attr_2412.attr,
+ &dev_attr_dse.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_ctrlb_grp = {
+ .name = "ctrlb",
+ .attrs = ds1685_rtc_sysfs_ctrlb_attrs,
+};
+
+/*
+ * Control Register C bits.
+ *
+ * Reading Control C clears these bits! Reading them individually can
+ * possibly cause an interrupt to be missed. Use the /proc interface
+ * to see all the bits in this register simultaneously.
+ */
+DS1685_RTC_SYSFS_CTRL_REG_RO(irqf);
+DS1685_RTC_SYSFS_CTRL_REG_RO(pf);
+DS1685_RTC_SYSFS_CTRL_REG_RO(af);
+DS1685_RTC_SYSFS_CTRL_REG_RO(uf);
+
+static struct attribute*
+ds1685_rtc_sysfs_ctrlc_attrs[] = {
+ &dev_attr_irqf.attr,
+ &dev_attr_pf.attr,
+ &dev_attr_af.attr,
+ &dev_attr_uf.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_ctrlc_grp = {
+ .name = "ctrlc",
+ .attrs = ds1685_rtc_sysfs_ctrlc_attrs,
+};
+
+/*
+ * Control Register D bits.
+ */
+DS1685_RTC_SYSFS_CTRL_REG_RO(vrt);
+
+static struct attribute*
+ds1685_rtc_sysfs_ctrld_attrs[] = {
+ &dev_attr_vrt.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_ctrld_grp = {
+ .name = "ctrld",
+ .attrs = ds1685_rtc_sysfs_ctrld_attrs,
+};
+
+/*
+ * Control Register 4A bits.
+ */
+DS1685_RTC_SYSFS_CTRL_REG_RO(vrt2);
+DS1685_RTC_SYSFS_CTRL_REG_RO(incr);
+DS1685_RTC_SYSFS_CTRL_REG_RW(pab);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rf);
+DS1685_RTC_SYSFS_CTRL_REG_RW(wf);
+DS1685_RTC_SYSFS_CTRL_REG_RW(kf);
+#if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
+DS1685_RTC_SYSFS_CTRL_REG_RO(bme);
+#endif
+
+static struct attribute*
+ds1685_rtc_sysfs_ctrl4a_attrs[] = {
+ &dev_attr_vrt2.attr,
+ &dev_attr_incr.attr,
+ &dev_attr_pab.attr,
+ &dev_attr_rf.attr,
+ &dev_attr_wf.attr,
+ &dev_attr_kf.attr,
+#if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
+ &dev_attr_bme.attr,
+#endif
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_ctrl4a_grp = {
+ .name = "ctrl4a",
+ .attrs = ds1685_rtc_sysfs_ctrl4a_attrs,
+};
+
+/*
+ * Control Register 4B bits.
+ */
+DS1685_RTC_SYSFS_CTRL_REG_RW(abe);
+DS1685_RTC_SYSFS_CTRL_REG_RW(e32k);
+DS1685_RTC_SYSFS_CTRL_REG_RO(cs);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rce);
+DS1685_RTC_SYSFS_CTRL_REG_RW(prs);
+DS1685_RTC_SYSFS_CTRL_REG_RW(rie);
+DS1685_RTC_SYSFS_CTRL_REG_RW(wie);
+DS1685_RTC_SYSFS_CTRL_REG_RW(kse);
+
+static struct attribute*
+ds1685_rtc_sysfs_ctrl4b_attrs[] = {
+ &dev_attr_abe.attr,
+ &dev_attr_e32k.attr,
+ &dev_attr_cs.attr,
+ &dev_attr_rce.attr,
+ &dev_attr_prs.attr,
+ &dev_attr_rie.attr,
+ &dev_attr_wie.attr,
+ &dev_attr_kse.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_ctrl4b_grp = {
+ .name = "ctrl4b",
+ .attrs = ds1685_rtc_sysfs_ctrl4b_attrs,
+};
+
+
+/**
+ * struct ds1685_rtc_ctrl_regs.
+ * @name: char pointer for the bit name.
+ * @reg: control register the bit is in.
+ * @bit: the bit's offset in the register.
+ */
+struct ds1685_rtc_time_regs {
+ const char *name;
+ const u8 reg;
+ const u8 mask;
+ const u8 min;
+ const u8 max;
+};
+
+/*
+ * Time/Date register lookup tables.
+ */
+static const struct ds1685_rtc_time_regs
+ds1685_time_regs_bcd_table[] = {
+ { "seconds", RTC_SECS, RTC_SECS_BCD_MASK, 0, 59 },
+ { "minutes", RTC_MINS, RTC_MINS_BCD_MASK, 0, 59 },
+ { "hours", RTC_HRS, RTC_HRS_24_BCD_MASK, 0, 23 },
+ { "wday", RTC_WDAY, RTC_WDAY_MASK, 1, 7 },
+ { "mday", RTC_MDAY, RTC_MDAY_BCD_MASK, 1, 31 },
+ { "month", RTC_MONTH, RTC_MONTH_BCD_MASK, 1, 12 },
+ { "year", RTC_YEAR, RTC_YEAR_BCD_MASK, 0, 99 },
+ { "century", RTC_CENTURY, RTC_CENTURY_MASK, 0, 99 },
+ { "alarm_seconds", RTC_SECS_ALARM, RTC_SECS_BCD_MASK, 0, 59 },
+ { "alarm_minutes", RTC_MINS_ALARM, RTC_MINS_BCD_MASK, 0, 59 },
+ { "alarm_hours", RTC_HRS_ALARM, RTC_HRS_24_BCD_MASK, 0, 23 },
+ { "alarm_mday", RTC_MDAY_ALARM, RTC_MDAY_ALARM_MASK, 1, 31 },
+ { NULL, 0, 0, 0, 0 },
+};
+
+static const struct ds1685_rtc_time_regs
+ds1685_time_regs_bin_table[] = {
+ { "seconds", RTC_SECS, RTC_SECS_BIN_MASK, 0x00, 0x3b },
+ { "minutes", RTC_MINS, RTC_MINS_BIN_MASK, 0x00, 0x3b },
+ { "hours", RTC_HRS, RTC_HRS_24_BIN_MASK, 0x00, 0x17 },
+ { "wday", RTC_WDAY, RTC_WDAY_MASK, 0x01, 0x07 },
+ { "mday", RTC_MDAY, RTC_MDAY_BIN_MASK, 0x01, 0x1f },
+ { "month", RTC_MONTH, RTC_MONTH_BIN_MASK, 0x01, 0x0c },
+ { "year", RTC_YEAR, RTC_YEAR_BIN_MASK, 0x00, 0x63 },
+ { "century", RTC_CENTURY, RTC_CENTURY_MASK, 0x00, 0x63 },
+ { "alarm_seconds", RTC_SECS_ALARM, RTC_SECS_BIN_MASK, 0x00, 0x3b },
+ { "alarm_minutes", RTC_MINS_ALARM, RTC_MINS_BIN_MASK, 0x00, 0x3b },
+ { "alarm_hours", RTC_HRS_ALARM, RTC_HRS_24_BIN_MASK, 0x00, 0x17 },
+ { "alarm_mday", RTC_MDAY_ALARM, RTC_MDAY_ALARM_MASK, 0x01, 0x1f },
+ { NULL, 0, 0, 0x00, 0x00 },
+};
+
+/**
+ * ds1685_rtc_sysfs_time_regs_bcd_lookup - time/date reg bit lookup function.
+ * @name: register bit to look up in ds1685_time_regs_bcd_table.
+ */
+static const struct ds1685_rtc_time_regs*
+ds1685_rtc_sysfs_time_regs_lookup(const char *name, bool bcd_mode)
+{
+ const struct ds1685_rtc_time_regs *p;
+
+ if (bcd_mode)
+ p = ds1685_time_regs_bcd_table;
+ else
+ p = ds1685_time_regs_bin_table;
+
+ for (; p->name != NULL; ++p)
+ if (strcmp(p->name, name) == 0)
+ return p;
+
+ return NULL;
+}
+
+/**
+ * ds1685_rtc_sysfs_time_regs_show - reads a time/date register via sysfs.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ */
+static ssize_t
+ds1685_rtc_sysfs_time_regs_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ u8 tmp;
+ struct ds1685_priv *rtc = dev_get_drvdata(dev);
+ const struct ds1685_rtc_time_regs *bcd_reg_info =
+ ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, true);
+ const struct ds1685_rtc_time_regs *bin_reg_info =
+ ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, false);
+
+ /* Make sure we actually matched something. */
+ if (!bcd_reg_info && !bin_reg_info)
+ return -EINVAL;
+
+ /* bcd_reg_info->reg == bin_reg_info->reg. */
+ ds1685_rtc_begin_data_access(rtc);
+ tmp = rtc->read(rtc, bcd_reg_info->reg);
+ ds1685_rtc_end_data_access(rtc);
+
+ tmp = ds1685_rtc_bcd2bin(rtc, tmp, bcd_reg_info->mask,
+ bin_reg_info->mask);
+
+ return snprintf(buf, 4, "%d\n", tmp);
+}
+
+/**
+ * ds1685_rtc_sysfs_time_regs_store - writes a time/date register via sysfs.
+ * @dev: pointer to device structure.
+ * @attr: pointer to device_attribute structure.
+ * @buf: pointer to char array to hold the output.
+ * @count: number of bytes written.
+ */
+static ssize_t
+ds1685_rtc_sysfs_time_regs_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ long int val = 0;
+ struct ds1685_priv *rtc = dev_get_drvdata(dev);
+ const struct ds1685_rtc_time_regs *bcd_reg_info =
+ ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, true);
+ const struct ds1685_rtc_time_regs *bin_reg_info =
+ ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, false);
+
+ /* We only accept numbers. */
+ if (kstrtol(buf, 10, &val) < 0)
+ return -EINVAL;
+
+ /* Make sure we actually matched something. */
+ if (!bcd_reg_info && !bin_reg_info)
+ return -EINVAL;
+
+ /* Check for a valid range. */
+ if (rtc->bcd_mode) {
+ if ((val < bcd_reg_info->min) || (val > bcd_reg_info->max))
+ return -ERANGE;
+ } else {
+ if ((val < bin_reg_info->min) || (val > bin_reg_info->max))
+ return -ERANGE;
+ }
+
+ val = ds1685_rtc_bin2bcd(rtc, val, bin_reg_info->mask,
+ bcd_reg_info->mask);
+
+ /* bcd_reg_info->reg == bin_reg_info->reg. */
+ ds1685_rtc_begin_data_access(rtc);
+ rtc->write(rtc, bcd_reg_info->reg, val);
+ ds1685_rtc_end_data_access(rtc);
+
+ return count;
+}
+
+/**
+ * DS1685_RTC_SYSFS_REG_RW - device_attribute for a read-write time register.
+ * @reg: time/date register to read or write.
+ */
+#define DS1685_RTC_SYSFS_TIME_REG_RW(reg) \
+ static DEVICE_ATTR(reg, S_IRUGO | S_IWUSR, \
+ ds1685_rtc_sysfs_time_regs_show, \
+ ds1685_rtc_sysfs_time_regs_store)
+
+/*
+ * Time/Date Register bits.
+ */
+DS1685_RTC_SYSFS_TIME_REG_RW(seconds);
+DS1685_RTC_SYSFS_TIME_REG_RW(minutes);
+DS1685_RTC_SYSFS_TIME_REG_RW(hours);
+DS1685_RTC_SYSFS_TIME_REG_RW(wday);
+DS1685_RTC_SYSFS_TIME_REG_RW(mday);
+DS1685_RTC_SYSFS_TIME_REG_RW(month);
+DS1685_RTC_SYSFS_TIME_REG_RW(year);
+DS1685_RTC_SYSFS_TIME_REG_RW(century);
+DS1685_RTC_SYSFS_TIME_REG_RW(alarm_seconds);
+DS1685_RTC_SYSFS_TIME_REG_RW(alarm_minutes);
+DS1685_RTC_SYSFS_TIME_REG_RW(alarm_hours);
+DS1685_RTC_SYSFS_TIME_REG_RW(alarm_mday);
+
+static struct attribute*
+ds1685_rtc_sysfs_time_attrs[] = {
+ &dev_attr_seconds.attr,
+ &dev_attr_minutes.attr,
+ &dev_attr_hours.attr,
+ &dev_attr_wday.attr,
+ &dev_attr_mday.attr,
+ &dev_attr_month.attr,
+ &dev_attr_year.attr,
+ &dev_attr_century.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_time_grp = {
+ .name = "datetime",
+ .attrs = ds1685_rtc_sysfs_time_attrs,
+};
+
+static struct attribute*
+ds1685_rtc_sysfs_alarm_attrs[] = {
+ &dev_attr_alarm_seconds.attr,
+ &dev_attr_alarm_minutes.attr,
+ &dev_attr_alarm_hours.attr,
+ &dev_attr_alarm_mday.attr,
+ NULL,
+};
+
+static const struct attribute_group
+ds1685_rtc_sysfs_alarm_grp = {
+ .name = "alarm",
+ .attrs = ds1685_rtc_sysfs_alarm_attrs,
+};
+#endif /* CONFIG_RTC_DS1685_SYSFS_REGS */
+
+
+/**
+ * ds1685_rtc_sysfs_register - register sysfs files.
+ * @dev: pointer to device structure.
+ */
+static int
+ds1685_rtc_sysfs_register(struct device *dev)
+{
+ int ret = 0;
+
+ sysfs_bin_attr_init(&ds1685_rtc_sysfs_nvram_attr);
+ ret = sysfs_create_bin_file(&dev->kobj, &ds1685_rtc_sysfs_nvram_attr);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_misc_grp);
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_RTC_DS1685_SYSFS_REGS
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrla_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlb_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlc_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrld_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4a_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4b_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_time_grp);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_alarm_grp);
+ if (ret)
+ return ret;
+#endif
+ return 0;
+}
+
+/**
+ * ds1685_rtc_sysfs_unregister - unregister sysfs files.
+ * @dev: pointer to device structure.
+ */
+static int
+ds1685_rtc_sysfs_unregister(struct device *dev)
+{
+ sysfs_remove_bin_file(&dev->kobj, &ds1685_rtc_sysfs_nvram_attr);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_misc_grp);
+
+#ifdef CONFIG_RTC_DS1685_SYSFS_REGS
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrla_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlb_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlc_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrld_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4a_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4b_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_time_grp);
+ sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_alarm_grp);
+#endif
+
+ return 0;
+}
+#endif /* CONFIG_SYSFS */
+
+
+
+/* ----------------------------------------------------------------------- */
+/* Driver Probe/Removal */
+
+/**
+ * ds1685_rtc_probe - initializes rtc driver.
+ * @pdev: pointer to platform_device structure.
+ */
+static int
+ds1685_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc_dev;
+ struct resource *res;
+ struct ds1685_priv *rtc;
+ struct ds1685_rtc_platform_data *pdata;
+ u8 ctrla, ctrlb, hours;
+ unsigned char am_pm;
+ int ret = 0;
+
+ /* Get the platform data. */
+ pdata = (struct ds1685_rtc_platform_data *) pdev->dev.platform_data;
+ if (!pdata)
+ return -ENODEV;
+
+ /* Allocate memory for the rtc device. */
+ rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ /*
+ * Allocate/setup any IORESOURCE_MEM resources, if required. Not all
+ * platforms put the RTC in an easy-access place. Like the SGI Octane,
+ * which attaches the RTC to a "ByteBus", hooked to a SuperIO chip
+ * that sits behind the IOC3 PCI metadevice.
+ */
+ if (pdata->alloc_io_resources) {
+ /* Get the platform resources. */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENXIO;
+ rtc->size = resource_size(res);
+
+ /* Request a memory region. */
+ /* XXX: mmio-only for now. */
+ if (!devm_request_mem_region(&pdev->dev, res->start, rtc->size,
+ pdev->name))
+ return -EBUSY;
+
+ /*
+ * Set the base address for the rtc, and ioremap its
+ * registers.
+ */
+ rtc->baseaddr = res->start;
+ rtc->regs = devm_ioremap(&pdev->dev, res->start, rtc->size);
+ if (!rtc->regs)
+ return -ENOMEM;
+ }
+ rtc->alloc_io_resources = pdata->alloc_io_resources;
+
+ /* Get the register step size. */
+ if (pdata->regstep > 0)
+ rtc->regstep = pdata->regstep;
+ else
+ rtc->regstep = 1;
+
+ /* Platform read function, else default if mmio setup */
+ if (pdata->plat_read)
+ rtc->read = pdata->plat_read;
+ else
+ if (pdata->alloc_io_resources)
+ rtc->read = ds1685_read;
+ else
+ return -ENXIO;
+
+ /* Platform write function, else default if mmio setup */
+ if (pdata->plat_write)
+ rtc->write = pdata->plat_write;
+ else
+ if (pdata->alloc_io_resources)
+ rtc->write = ds1685_write;
+ else
+ return -ENXIO;
+
+ /* Platform pre-shutdown function, if defined. */
+ if (pdata->plat_prepare_poweroff)
+ rtc->prepare_poweroff = pdata->plat_prepare_poweroff;
+
+ /* Platform wake_alarm function, if defined. */
+ if (pdata->plat_wake_alarm)
+ rtc->wake_alarm = pdata->plat_wake_alarm;
+
+ /* Platform post_ram_clear function, if defined. */
+ if (pdata->plat_post_ram_clear)
+ rtc->post_ram_clear = pdata->plat_post_ram_clear;
+
+ /* Init the spinlock, workqueue, & set the driver data. */
+ spin_lock_init(&rtc->lock);
+ INIT_WORK(&rtc->work, ds1685_rtc_work_queue);
+ platform_set_drvdata(pdev, rtc);
+
+ /* Turn the oscillator on if is not already on (DV1 = 1). */
+ ctrla = rtc->read(rtc, RTC_CTRL_A);
+ if (!(ctrla & RTC_CTRL_A_DV1))
+ ctrla |= RTC_CTRL_A_DV1;
+
+ /* Enable the countdown chain (DV2 = 0) */
+ ctrla &= ~(RTC_CTRL_A_DV2);
+
+ /* Clear RS3-RS0 in Control A. */
+ ctrla &= ~(RTC_CTRL_A_RS_MASK);
+
+ /*
+ * All done with Control A. Switch to Bank 1 for the remainder of
+ * the RTC setup so we have access to the extended functions.
+ */
+ ctrla |= RTC_CTRL_A_DV0;
+ rtc->write(rtc, RTC_CTRL_A, ctrla);
+
+ /* Default to 32768kHz output. */
+ rtc->write(rtc, RTC_EXT_CTRL_4B,
+ (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_E32K));
+
+ /* Set the SET bit in Control B so we can do some housekeeping. */
+ rtc->write(rtc, RTC_CTRL_B,
+ (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
+
+ /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
+ while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
+ cpu_relax();
+
+ /*
+ * If the platform supports BCD mode, then set DM=0 in Control B.
+ * Otherwise, set DM=1 for BIN mode.
+ */
+ ctrlb = rtc->read(rtc, RTC_CTRL_B);
+ if (pdata->bcd_mode)
+ ctrlb &= ~(RTC_CTRL_B_DM);
+ else
+ ctrlb |= RTC_CTRL_B_DM;
+ rtc->bcd_mode = pdata->bcd_mode;
+
+ /*
+ * Disable Daylight Savings Time (DSE = 0).
+ * The RTC has hardcoded timezone information that is rendered
+ * obselete. We'll let the OS deal with DST settings instead.
+ */
+ if (ctrlb & RTC_CTRL_B_DSE)
+ ctrlb &= ~(RTC_CTRL_B_DSE);
+
+ /* Force 24-hour mode (2412 = 1). */
+ if (!(ctrlb & RTC_CTRL_B_2412)) {
+ /* Reinitialize the time hours. */
+ hours = rtc->read(rtc, RTC_HRS);
+ am_pm = hours & RTC_HRS_AMPM_MASK;
+ hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
+ RTC_HRS_12_BIN_MASK);
+ hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
+
+ /* Enable 24-hour mode. */
+ ctrlb |= RTC_CTRL_B_2412;
+
+ /* Write back to Control B, including DM & DSE bits. */
+ rtc->write(rtc, RTC_CTRL_B, ctrlb);
+
+ /* Write the time hours back. */
+ rtc->write(rtc, RTC_HRS,
+ ds1685_rtc_bin2bcd(rtc, hours,
+ RTC_HRS_24_BIN_MASK,
+ RTC_HRS_24_BCD_MASK));
+
+ /* Reinitialize the alarm hours. */
+ hours = rtc->read(rtc, RTC_HRS_ALARM);
+ am_pm = hours & RTC_HRS_AMPM_MASK;
+ hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
+ RTC_HRS_12_BIN_MASK);
+ hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
+
+ /* Write the alarm hours back. */
+ rtc->write(rtc, RTC_HRS_ALARM,
+ ds1685_rtc_bin2bcd(rtc, hours,
+ RTC_HRS_24_BIN_MASK,
+ RTC_HRS_24_BCD_MASK));
+ } else {
+ /* 24-hour mode is already set, so write Control B back. */
+ rtc->write(rtc, RTC_CTRL_B, ctrlb);
+ }
+
+ /* Unset the SET bit in Control B so the RTC can update. */
+ rtc->write(rtc, RTC_CTRL_B,
+ (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
+
+ /* Check the main battery. */
+ if (!(rtc->read(rtc, RTC_CTRL_D) & RTC_CTRL_D_VRT))
+ dev_warn(&pdev->dev,
+ "Main battery is exhausted! RTC may be invalid!\n");
+
+ /* Check the auxillary battery. It is optional. */
+ if (!(rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_VRT2))
+ dev_warn(&pdev->dev,
+ "Aux battery is exhausted or not available.\n");
+
+ /* Read Ctrl B and clear PIE/AIE/UIE. */
+ rtc->write(rtc, RTC_CTRL_B,
+ (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_PAU_MASK)));
+
+ /* Reading Ctrl C auto-clears PF/AF/UF. */
+ rtc->read(rtc, RTC_CTRL_C);
+
+ /* Read Ctrl 4B and clear RIE/WIE/KSE. */
+ rtc->write(rtc, RTC_EXT_CTRL_4B,
+ (rtc->read(rtc, RTC_EXT_CTRL_4B) & ~(RTC_CTRL_4B_RWK_MASK)));
+
+ /* Clear RF/WF/KF in Ctrl 4A. */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (rtc->read(rtc, RTC_EXT_CTRL_4A) & ~(RTC_CTRL_4A_RWK_MASK)));
+
+ /*
+ * Re-enable KSE to handle power button events. We do not enable
+ * WIE or RIE by default.
+ */
+ rtc->write(rtc, RTC_EXT_CTRL_4B,
+ (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_KSE));
+
+ /*
+ * Fetch the IRQ and setup the interrupt handler.
+ *
+ * Not all platforms have the IRQF pin tied to something. If not, the
+ * RTC will still set the *IE / *F flags and raise IRQF in ctrlc, but
+ * there won't be an automatic way of notifying the kernel about it,
+ * unless ctrlc is explicitly polled.
+ */
+ if (!pdata->no_irq) {
+ ret = platform_get_irq(pdev, 0);
+ if (ret > 0) {
+ rtc->irq_num = ret;
+
+ /* Request an IRQ. */
+ ret = devm_request_irq(&pdev->dev, rtc->irq_num,
+ ds1685_rtc_irq_handler,
+ IRQF_SHARED, pdev->name, pdev);
+
+ /* Check to see if something came back. */
+ if (unlikely(ret)) {
+ dev_warn(&pdev->dev,
+ "RTC interrupt not available\n");
+ rtc->irq_num = 0;
+ }
+ } else
+ return ret;
+ }
+ rtc->no_irq = pdata->no_irq;
+
+ /* Setup complete. */
+ ds1685_rtc_switch_to_bank0(rtc);
+
+ /* Register the device as an RTC. */
+ rtc_dev = rtc_device_register(pdev->name, &pdev->dev,
+ &ds1685_rtc_ops, THIS_MODULE);
+
+ /* Success? */
+ if (IS_ERR(rtc_dev))
+ return PTR_ERR(rtc_dev);
+
+ /* Maximum periodic rate is 8192Hz (0.122070ms). */
+ rtc_dev->max_user_freq = RTC_MAX_USER_FREQ;
+
+ /* See if the platform doesn't support UIE. */
+ if (pdata->uie_unsupported)
+ rtc_dev->uie_unsupported = 1;
+ rtc->uie_unsupported = pdata->uie_unsupported;
+
+ rtc->dev = rtc_dev;
+
+#ifdef CONFIG_SYSFS
+ ret = ds1685_rtc_sysfs_register(&pdev->dev);
+ if (ret)
+ rtc_device_unregister(rtc->dev);
+#endif
+
+ /* Done! */
+ return ret;
+}
+
+/**
+ * ds1685_rtc_remove - removes rtc driver.
+ * @pdev: pointer to platform_device structure.
+ */
+static int
+ds1685_rtc_remove(struct platform_device *pdev)
+{
+ struct ds1685_priv *rtc = platform_get_drvdata(pdev);
+
+#ifdef CONFIG_SYSFS
+ ds1685_rtc_sysfs_unregister(&pdev->dev);
+#endif
+
+ rtc_device_unregister(rtc->dev);
+
+ /* Read Ctrl B and clear PIE/AIE/UIE. */
+ rtc->write(rtc, RTC_CTRL_B,
+ (rtc->read(rtc, RTC_CTRL_B) &
+ ~(RTC_CTRL_B_PAU_MASK)));
+
+ /* Reading Ctrl C auto-clears PF/AF/UF. */
+ rtc->read(rtc, RTC_CTRL_C);
+
+ /* Read Ctrl 4B and clear RIE/WIE/KSE. */
+ rtc->write(rtc, RTC_EXT_CTRL_4B,
+ (rtc->read(rtc, RTC_EXT_CTRL_4B) &
+ ~(RTC_CTRL_4B_RWK_MASK)));
+
+ /* Manually clear RF/WF/KF in Ctrl 4A. */
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (rtc->read(rtc, RTC_EXT_CTRL_4A) &
+ ~(RTC_CTRL_4A_RWK_MASK)));
+
+ cancel_work_sync(&rtc->work);
+
+ return 0;
+}
+
+/**
+ * ds1685_rtc_driver - rtc driver properties.
+ */
+static struct platform_driver ds1685_rtc_driver = {
+ .driver = {
+ .name = "rtc-ds1685",
+ .owner = THIS_MODULE,
+ },
+ .probe = ds1685_rtc_probe,
+ .remove = ds1685_rtc_remove,
+};
+
+/**
+ * ds1685_rtc_init - rtc module init.
+ */
+static int __init
+ds1685_rtc_init(void)
+{
+ return platform_driver_register(&ds1685_rtc_driver);
+}
+
+/**
+ * ds1685_rtc_exit - rtc module exit.
+ */
+static void __exit
+ds1685_rtc_exit(void)
+{
+ platform_driver_unregister(&ds1685_rtc_driver);
+}
+
+module_init(ds1685_rtc_init);
+module_exit(ds1685_rtc_exit);
+/* ----------------------------------------------------------------------- */
+
+
+/* ----------------------------------------------------------------------- */
+/* Poweroff function */
+
+/**
+ * ds1685_rtc_poweroff - uses the RTC chip to power the system off.
+ * @pdev: pointer to platform_device structure.
+ */
+extern void __noreturn
+ds1685_rtc_poweroff(struct platform_device *pdev)
+{
+ u8 ctrla, ctrl4a, ctrl4b;
+ struct ds1685_priv *rtc;
+
+ /* Check for valid RTC data, else, spin forever. */
+ if (unlikely(!pdev)) {
+ pr_emerg("rtc-ds1685: platform device data not available, spinning forever ...\n");
+ unreachable();
+ } else {
+ /* Get the rtc data. */
+ rtc = platform_get_drvdata(pdev);
+
+ /*
+ * Disable our IRQ. We're powering down, so we're not
+ * going to worry about cleaning up. Most of that should
+ * have been taken care of by the shutdown scripts and this
+ * is the final function call.
+ */
+ if (!rtc->no_irq)
+ disable_irq_nosync(rtc->irq_num);
+
+ /* Oscillator must be on and the countdown chain enabled. */
+ ctrla = rtc->read(rtc, RTC_CTRL_A);
+ ctrla |= RTC_CTRL_A_DV1;
+ ctrla &= ~(RTC_CTRL_A_DV2);
+ rtc->write(rtc, RTC_CTRL_A, ctrla);
+
+ /*
+ * Read Control 4A and check the status of the auxillary
+ * battery. This must be present and working (VRT2 = 1)
+ * for wakeup and kickstart functionality to be useful.
+ */
+ ds1685_rtc_switch_to_bank1(rtc);
+ ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
+ if (ctrl4a & RTC_CTRL_4A_VRT2) {
+ /* Clear all of the interrupt flags on Control 4A. */
+ ctrl4a &= ~(RTC_CTRL_4A_RWK_MASK);
+ rtc->write(rtc, RTC_EXT_CTRL_4A, ctrl4a);
+
+ /*
+ * The auxillary battery is present and working.
+ * Enable extended functions (ABE=1), enable
+ * wake-up (WIE=1), and enable kickstart (KSE=1)
+ * in Control 4B.
+ */
+ ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
+ ctrl4b |= (RTC_CTRL_4B_ABE | RTC_CTRL_4B_WIE |
+ RTC_CTRL_4B_KSE);
+ rtc->write(rtc, RTC_EXT_CTRL_4B, ctrl4b);
+ }
+
+ /* Set PAB to 1 in Control 4A to power the system down. */
+ dev_warn(&pdev->dev, "Powerdown.\n");
+ msleep(20);
+ rtc->write(rtc, RTC_EXT_CTRL_4A,
+ (ctrl4a | RTC_CTRL_4A_PAB));
+
+ /* Spin ... we do not switch back to bank0. */
+ unreachable();
+ }
+}
+EXPORT_SYMBOL(ds1685_rtc_poweroff);
+/* ----------------------------------------------------------------------- */
+
+
+MODULE_AUTHOR("Joshua Kinard <kumba@xxxxxxxxxx>");
+MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@xxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Dallas/Maxim DS1685/DS1687-series RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+MODULE_ALIAS("platform:rtc-ds1685");
diff --git a/include/linux/rtc/ds1685.h b/include/linux/rtc/ds1685.h
new file mode 100644
index 0000000..e6337a5
--- /dev/null
+++ b/include/linux/rtc/ds1685.h
@@ -0,0 +1,375 @@
+/*
+ * Definitions for the registers, addresses, and platform data of the
+ * DS1685/DS1687-series RTC chips.
+ *
+ * This Driver also works for the DS17X85/DS17X87 RTC chips. Functionally
+ * similar to the DS1685/DS1687, they support a few extra features which
+ * include larger, battery-backed NV-SRAM, burst-mode access, and an RTC
+ * write counter.
+ *
+ * Copyright (C) 2011-2014 Joshua Kinard <kumba@xxxxxxxxxx>.
+ * Copyright (C) 2009 Matthias Fuchs <matthias.fuchs@xxxxxxxxxxxxxxxxxxx>.
+ *
+ * References:
+ * DS1685/DS1687 3V/5V Real-Time Clocks, 19-5215, Rev 4/10.
+ * DS17x85/DS17x87 3V/5V Real-Time Clocks, 19-5222, Rev 4/10.
+ * DS1689/DS1693 3V/5V Serialized Real-Time Clocks, Rev 112105.
+ * Application Note 90, Using the Multiplex Bus RTC Extended Features.
+ *
+ * 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.
+ */
+
+#ifndef _LINUX_RTC_DS1685_H_
+#define _LINUX_RTC_DS1685_H_
+
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+
+/**
+ * struct ds1685_priv - DS1685 private data structure.
+ * @dev: pointer to the rtc_device structure.
+ * @regs: iomapped base address pointer of the RTC registers.
+ * @regstep: padding/step size between registers (optional).
+ * @baseaddr: base address of the RTC device.
+ * @size: resource size.
+ * @lock: private lock variable for spin locking/unlocking.
+ * @work: private workqueue.
+ * @irq: IRQ number assigned to the RTC device.
+ * @prepare_poweroff: pointer to platform pre-poweroff function.
+ * @wake_alarm: pointer to platform wake alarm function.
+ * @post_ram_clear: pointer to platform post ram-clear function.
+ */
+struct ds1685_priv {
+ struct rtc_device *dev;
+ void __iomem *regs;
+ u32 regstep;
+ resource_size_t baseaddr;
+ size_t size;
+ spinlock_t lock;
+ struct work_struct work;
+ int irq_num;
+ bool bcd_mode;
+ bool no_irq;
+ bool uie_unsupported;
+ bool alloc_io_resources;
+ u8 (*read)(struct ds1685_priv *, int);
+ void (*write)(struct ds1685_priv *, int, u8);
+ void (*prepare_poweroff)(void);
+ void (*wake_alarm)(void);
+ void (*post_ram_clear)(void);
+};
+
+
+/**
+ * struct ds1685_rtc_platform_data - platform data structure.
+ * @plat_prepare_poweroff: platform-specific pre-poweroff function.
+ * @plat_wake_alarm: platform-specific wake alarm function.
+ * @plat_post_ram_clear: platform-specific post ram-clear function.
+ *
+ * If your platform needs to use a custom padding/step size between
+ * registers, or uses one or more of the extended interrupts and needs special
+ * handling, then include this header file in your platform definition and
+ * set regstep and the plat_* pointers as appropriate.
+ */
+struct ds1685_rtc_platform_data {
+ const u32 regstep;
+ const bool bcd_mode;
+ const bool no_irq;
+ const bool uie_unsupported;
+ const bool alloc_io_resources;
+ u8 (*plat_read)(struct ds1685_priv *, int);
+ void (*plat_write)(struct ds1685_priv *, int, u8);
+ void (*plat_prepare_poweroff)(void);
+ void (*plat_wake_alarm)(void);
+ void (*plat_post_ram_clear)(void);
+};
+
+
+/*
+ * Time Registers.
+ */
+#define RTC_SECS 0x00 /* Seconds 00-59 */
+#define RTC_SECS_ALARM 0x01 /* Alarm Seconds 00-59 */
+#define RTC_MINS 0x02 /* Minutes 00-59 */
+#define RTC_MINS_ALARM 0x03 /* Alarm Minutes 00-59 */
+#define RTC_HRS 0x04 /* Hours 01-12 AM/PM || 00-23 */
+#define RTC_HRS_ALARM 0x05 /* Alarm Hours 01-12 AM/PM || 00-23 */
+#define RTC_WDAY 0x06 /* Day of Week 01-07 */
+#define RTC_MDAY 0x07 /* Day of Month 01-31 */
+#define RTC_MONTH 0x08 /* Month 01-12 */
+#define RTC_YEAR 0x09 /* Year 00-99 */
+#define RTC_CENTURY 0x48 /* Century 00-99 */
+#define RTC_MDAY_ALARM 0x49 /* Alarm Day of Month 01-31 */
+
+
+/*
+ * Bit masks for the Time registers in BCD Mode (DM = 0).
+ */
+#define RTC_SECS_BCD_MASK 0x7f /* - x x x x x x x */
+#define RTC_MINS_BCD_MASK 0x7f /* - x x x x x x x */
+#define RTC_HRS_12_BCD_MASK 0x1f /* - - - x x x x x */
+#define RTC_HRS_24_BCD_MASK 0x3f /* - - x x x x x x */
+#define RTC_MDAY_BCD_MASK 0x3f /* - - x x x x x x */
+#define RTC_MONTH_BCD_MASK 0x1f /* - - - x x x x x */
+#define RTC_YEAR_BCD_MASK 0xff /* x x x x x x x x */
+
+/*
+ * Bit masks for the Time registers in BIN Mode (DM = 1).
+ */
+#define RTC_SECS_BIN_MASK 0x3f /* - - x x x x x x */
+#define RTC_MINS_BIN_MASK 0x3f /* - - x x x x x x */
+#define RTC_HRS_12_BIN_MASK 0x0f /* - - - - x x x x */
+#define RTC_HRS_24_BIN_MASK 0x1f /* - - - x x x x x */
+#define RTC_MDAY_BIN_MASK 0x1f /* - - - x x x x x */
+#define RTC_MONTH_BIN_MASK 0x0f /* - - - - x x x x */
+#define RTC_YEAR_BIN_MASK 0x7f /* - x x x x x x x */
+
+/*
+ * Bit masks common for the Time registers in BCD or BIN Mode.
+ */
+#define RTC_WDAY_MASK 0x07 /* - - - - - x x x */
+#define RTC_CENTURY_MASK 0xff /* x x x x x x x x */
+#define RTC_MDAY_ALARM_MASK 0xff /* x x x x x x x x */
+#define RTC_HRS_AMPM_MASK BIT(7) /* Mask for the AM/PM bit */
+
+
+
+/*
+ * Control Registers.
+ */
+#define RTC_CTRL_A 0x0a /* Control Register A */
+#define RTC_CTRL_B 0x0b /* Control Register B */
+#define RTC_CTRL_C 0x0c /* Control Register C */
+#define RTC_CTRL_D 0x0d /* Control Register D */
+#define RTC_EXT_CTRL_4A 0x4a /* Extended Control Register 4A */
+#define RTC_EXT_CTRL_4B 0x4b /* Extended Control Register 4B */
+
+
+/*
+ * Bit names in Control Register A.
+ */
+#define RTC_CTRL_A_UIP BIT(7) /* Update In Progress */
+#define RTC_CTRL_A_DV2 BIT(6) /* Countdown Chain */
+#define RTC_CTRL_A_DV1 BIT(5) /* Oscillator Enable */
+#define RTC_CTRL_A_DV0 BIT(4) /* Bank Select */
+#define RTC_CTRL_A_RS2 BIT(2) /* Rate-Selection Bit 2 */
+#define RTC_CTRL_A_RS3 BIT(3) /* Rate-Selection Bit 3 */
+#define RTC_CTRL_A_RS1 BIT(1) /* Rate-Selection Bit 1 */
+#define RTC_CTRL_A_RS0 BIT(0) /* Rate-Selection Bit 0 */
+#define RTC_CTRL_A_RS_MASK 0x0f /* RS3 + RS2 + RS1 + RS0 */
+
+/*
+ * Bit names in Control Register B.
+ */
+#define RTC_CTRL_B_SET BIT(7) /* SET Bit */
+#define RTC_CTRL_B_PIE BIT(6) /* Periodic-Interrupt Enable */
+#define RTC_CTRL_B_AIE BIT(5) /* Alarm-Interrupt Enable */
+#define RTC_CTRL_B_UIE BIT(4) /* Update-Ended Interrupt-Enable */
+#define RTC_CTRL_B_SQWE BIT(3) /* Square-Wave Enable */
+#define RTC_CTRL_B_DM BIT(2) /* Data Mode */
+#define RTC_CTRL_B_2412 BIT(1) /* 12-Hr/24-Hr Mode */
+#define RTC_CTRL_B_DSE BIT(0) /* Daylight Savings Enable */
+#define RTC_CTRL_B_PAU_MASK 0x70 /* PIE + AIE + UIE */
+
+
+/*
+ * Bit names in Control Register C.
+ *
+ * BIT(0), BIT(1), BIT(2), & BIT(3) are unused, always return 0, and cannot
+ * be written to.
+ */
+#define RTC_CTRL_C_IRQF BIT(7) /* Interrupt-Request Flag */
+#define RTC_CTRL_C_PF BIT(6) /* Periodic-Interrupt Flag */
+#define RTC_CTRL_C_AF BIT(5) /* Alarm-Interrupt Flag */
+#define RTC_CTRL_C_UF BIT(4) /* Update-Ended Interrupt Flag */
+#define RTC_CTRL_C_PAU_MASK 0x70 /* PF + AF + UF */
+
+
+/*
+ * Bit names in Control Register D.
+ *
+ * BIT(0) through BIT(6) are unused, always return 0, and cannot
+ * be written to.
+ */
+#define RTC_CTRL_D_VRT BIT(7) /* Valid RAM and Time */
+
+
+/*
+ * Bit names in Extended Control Register 4A.
+ *
+ * On the DS1685/DS1687/DS1689/DS1693, BIT(4) and BIT(5) are reserved for
+ * future use. They can be read from and written to, but have no effect
+ * on the RTC's operation.
+ *
+ * On the DS17x85/DS17x87, BIT(5) is Burst-Mode Enable (BME), and allows
+ * access to the extended NV-SRAM by automatically incrementing the address
+ * register when they are read from or written to.
+ */
+#define RTC_CTRL_4A_VRT2 BIT(7) /* Auxillary Battery Status */
+#define RTC_CTRL_4A_INCR BIT(6) /* Increment-in-Progress Status */
+#define RTC_CTRL_4A_PAB BIT(3) /* Power-Active Bar Control */
+#define RTC_CTRL_4A_RF BIT(2) /* RAM-Clear Flag */
+#define RTC_CTRL_4A_WF BIT(1) /* Wake-Up Alarm Flag */
+#define RTC_CTRL_4A_KF BIT(0) /* Kickstart Flag */
+#if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
+#define RTC_CTRL_4A_BME BIT(5) /* Burst-Mode Enable */
+#endif
+#define RTC_CTRL_4A_RWK_MASK 0x07 /* RF + WF + KF */
+
+
+/*
+ * Bit names in Extended Control Register 4B.
+ */
+#define RTC_CTRL_4B_ABE BIT(7) /* Auxillary Battery Enable */
+#define RTC_CTRL_4B_E32K BIT(6) /* Enable 32.768Hz on SQW Pin */
+#define RTC_CTRL_4B_CS BIT(5) /* Crystal Select */
+#define RTC_CTRL_4B_RCE BIT(4) /* RAM Clear-Enable */
+#define RTC_CTRL_4B_PRS BIT(3) /* PAB Reset-Select */
+#define RTC_CTRL_4B_RIE BIT(2) /* RAM Clear-Interrupt Enable */
+#define RTC_CTRL_4B_WIE BIT(1) /* Wake-Up Alarm-Interrupt Enable */
+#define RTC_CTRL_4B_KSE BIT(0) /* Kickstart Interrupt-Enable */
+#define RTC_CTRL_4B_RWK_MASK 0x07 /* RIE + WIE + KSE */
+
+
+/*
+ * Misc register names in Bank 1.
+ *
+ * The DV0 bit in Control Register A must be set to 1 for these registers
+ * to become available, including Extended Control Registers 4A & 4B.
+ */
+#define RTC_BANK1_SSN_MODEL 0x40 /* Model Number */
+#define RTC_BANK1_SSN_BYTE_1 0x41 /* 1st Byte of Serial Number */
+#define RTC_BANK1_SSN_BYTE_2 0x42 /* 2nd Byte of Serial Number */
+#define RTC_BANK1_SSN_BYTE_3 0x43 /* 3rd Byte of Serial Number */
+#define RTC_BANK1_SSN_BYTE_4 0x44 /* 4th Byte of Serial Number */
+#define RTC_BANK1_SSN_BYTE_5 0x45 /* 5th Byte of Serial Number */
+#define RTC_BANK1_SSN_BYTE_6 0x46 /* 6th Byte of Serial Number */
+#define RTC_BANK1_SSN_CRC 0x47 /* Serial CRC Byte */
+#define RTC_BANK1_RAM_DATA_PORT 0x53 /* Extended RAM Data Port */
+
+
+/*
+ * Model-specific registers in Bank 1.
+ *
+ * The addresses below differ depending on the model of the RTC chip
+ * selected in the kernel configuration. Not all of these features are
+ * supported in the main driver at present.
+ *
+ * DS1685/DS1687 - Extended NV-SRAM address (LSB only).
+ * DS1689/DS1693 - Vcc, Vbat, Pwr Cycle Counters & Customer-specific S/N.
+ * DS17x85/DS17x87 - Extended NV-SRAM addresses (MSB & LSB) & Write counter.
+ */
+#if defined(CONFIG_RTC_DRV_DS1685)
+#define RTC_BANK1_RAM_ADDR 0x50 /* NV-SRAM Addr */
+#elif defined(CONFIG_RTC_DRV_DS1689)
+#define RTC_BANK1_VCC_CTR_LSB 0x54 /* Vcc Counter Addr (LSB) */
+#define RTC_BANK1_VCC_CTR_MSB 0x57 /* Vcc Counter Addr (MSB) */
+#define RTC_BANK1_VBAT_CTR_LSB 0x58 /* Vbat Counter Addr (LSB) */
+#define RTC_BANK1_VBAT_CTR_MSB 0x5b /* Vbat Counter Addr (MSB) */
+#define RTC_BANK1_PWR_CTR_LSB 0x5c /* Pwr Cycle Counter Addr (LSB) */
+#define RTC_BANK1_PWR_CTR_MSB 0x5d /* Pwr Cycle Counter Addr (MSB) */
+#define RTC_BANK1_UNIQ_SN 0x60 /* Customer-specific S/N */
+#else /* DS17x85/DS17x87 */
+#define RTC_BANK1_RAM_ADDR_LSB 0x50 /* NV-SRAM Addr (LSB) */
+#define RTC_BANK1_RAM_ADDR_MSB 0x51 /* NV-SRAM Addr (MSB) */
+#define RTC_BANK1_WRITE_CTR 0x5e /* RTC Write Counter */
+#endif
+
+
+/*
+ * Model numbers.
+ *
+ * The DS1688/DS1691 and DS1689/DS1693 chips share the same model number
+ * and the manual doesn't indicate any major differences. As such, they
+ * are regarded as the same chip in this driver.
+ */
+#define RTC_MODEL_DS1685 0x71 /* DS1685/DS1687 */
+#define RTC_MODEL_DS17285 0x72 /* DS17285/DS17287 */
+#define RTC_MODEL_DS1689 0x73 /* DS1688/DS1691/DS1689/DS1693 */
+#define RTC_MODEL_DS17485 0x74 /* DS17485/DS17487 */
+#define RTC_MODEL_DS17885 0x78 /* DS17885/DS17887 */
+
+
+/*
+ * Periodic Interrupt Rates / Square-Wave Output Frequency
+ *
+ * Periodic rates are selected by setting the RS3-RS0 bits in Control
+ * Register A and enabled via either the E32K bit in Extended Control
+ * Register 4B or the SQWE bit in Control Register B.
+ *
+ * E32K overrides the settings of RS3-RS0 and outputs a frequency of 32768Hz
+ * on the SQW pin of the RTC chip. While there are 16 possible selections,
+ * the 1-of-16 decoder is only able to divide the base 32768Hz signal into 13
+ * smaller frequencies. The values 0x01 and 0x02 are not used and are
+ * synonymous with 0x08 and 0x09, respectively.
+ *
+ * When E32K is set to a logic 1, periodic interrupts are disabled and reading
+ * /dev/rtc will return -EINVAL. This also applies if the periodic interrupt
+ * frequency is set to 0Hz.
+ *
+ * Not currently used by the rtc-ds1685 driver because the RTC core removed
+ * support for hardware-generated periodic-interrupts in favour of
+ * hrtimer-generated interrupts. But these defines are kept around for use
+ * in userland, as documentation to the hardware, and possible future use if
+ * hardware-generated periodic interrupts are ever added back.
+ */
+ /* E32K RS3 RS2 RS1 RS0 */
+#define RTC_SQW_8192HZ 0x03 /* 0 0 0 1 1 */
+#define RTC_SQW_4096HZ 0x04 /* 0 0 1 0 0 */
+#define RTC_SQW_2048HZ 0x05 /* 0 0 1 0 1 */
+#define RTC_SQW_1024HZ 0x06 /* 0 0 1 1 0 */
+#define RTC_SQW_512HZ 0x07 /* 0 0 1 1 1 */
+#define RTC_SQW_256HZ 0x08 /* 0 1 0 0 0 */
+#define RTC_SQW_128HZ 0x09 /* 0 1 0 0 1 */
+#define RTC_SQW_64HZ 0x0a /* 0 1 0 1 0 */
+#define RTC_SQW_32HZ 0x0b /* 0 1 0 1 1 */
+#define RTC_SQW_16HZ 0x0c /* 0 1 1 0 0 */
+#define RTC_SQW_8HZ 0x0d /* 0 1 1 0 1 */
+#define RTC_SQW_4HZ 0x0e /* 0 1 1 1 0 */
+#define RTC_SQW_2HZ 0x0f /* 0 1 1 1 1 */
+#define RTC_SQW_0HZ 0x00 /* 0 0 0 0 0 */
+#define RTC_SQW_32768HZ 32768 /* 1 - - - - */
+#define RTC_MAX_USER_FREQ 8192
+
+
+/*
+ * NVRAM data & addresses:
+ * - 50 bytes of NVRAM are available just past the clock registers.
+ * - 64 additional bytes are available in Bank0.
+ *
+ * Extended, battery-backed NV-SRAM:
+ * - DS1685/DS1687 - 128 bytes.
+ * - DS1689/DS1693 - 0 bytes.
+ * - DS17285/DS17287 - 2048 bytes.
+ * - DS17485/DS17487 - 4096 bytes.
+ * - DS17885/DS17887 - 8192 bytes.
+ */
+#define NVRAM_TIME_BASE 0x0e /* NVRAM Addr in Time regs */
+#define NVRAM_BANK0_BASE 0x40 /* NVRAM Addr in Bank0 regs */
+#define NVRAM_SZ_TIME 50
+#define NVRAM_SZ_BANK0 64
+#if defined(CONFIG_RTC_DRV_DS1685)
+# define NVRAM_SZ_EXTND 128
+#elif defined(CONFIG_RTC_DRV_DS1689)
+# define NVRAM_SZ_EXTND 0
+#elif defined(CONFIG_RTC_DRV_DS17285)
+# define NVRAM_SZ_EXTND 2048
+#elif defined(CONFIG_RTC_DRV_DS17485)
+# define NVRAM_SZ_EXTND 4096
+#elif defined(CONFIG_RTC_DRV_DS17885)
+# define NVRAM_SZ_EXTND 8192
+#endif
+#define NVRAM_TOTAL_SZ_BANK0 (NVRAM_SZ_TIME + NVRAM_SZ_BANK0)
+#define NVRAM_TOTAL_SZ (NVRAM_TOTAL_SZ_BANK0 + NVRAM_SZ_EXTND)
+
+
+/*
+ * Function Prototypes.
+ */
+extern void __noreturn
+ds1685_rtc_poweroff(struct platform_device *pdev);
+
+#endif /* _LINUX_RTC_DS1685_H_ */

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