/*
* An rtc driver for the Dallas/Maxim DS1685/DS1687 and related real-time
* chips.
*
* Copyright (C) 2011-2014 Joshua Kinard <kumba@gentoo.org>.
* Copyright (C) 2009 Matthias Fuchs <matthias.fuchs@esd-electronics.com>.
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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
/* ----------------------------------------------------------------------- */
/* 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);
}
/**
* s1685_rtc_check_mday - check validity of the day of month.
* @rtc: pointer to the ds1685 rtc structure.
* @mday: day of month.
*
* Returns -EDOM if the day of month is not within 1..31 range.
*/
static inline int
ds1685_rtc_check_mday(struct ds1685_priv *rtc, u8 mday)
{
if (rtc->bcd_mode) {
if (mday < 0x01 || mday > 0x31 || (mday & 0x0f) > 0x09)
return -EDOM;
} else {
if (mday < 1 || mday > 31)
return -EDOM;
}
return 0;
}
/**
* 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 ds1685_priv *rtc = dev_get_drvdata(dev);
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 0;
}
/**
* 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 ds1685_priv *rtc = dev_get_drvdata(dev);
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 ds1685_priv *rtc = dev_get_drvdata(dev);
u8 seconds, minutes, hours, mday, ctrlb, ctrlc;
int ret;
/* 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 the month date for validity. */
ret = ds1685_rtc_check_mday(rtc, mday);
if (ret)
return ret;
/*
* 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 and only assign when we care.
*/
if (likely(seconds < 0xc0))
alrm->time.tm_sec = ds1685_rtc_bcd2bin(rtc, seconds,
RTC_SECS_BCD_MASK,
RTC_SECS_BIN_MASK);
if (likely(minutes < 0xc0))
alrm->time.tm_min = ds1685_rtc_bcd2bin(rtc, minutes,
RTC_MINS_BCD_MASK,
RTC_MINS_BIN_MASK);
if (likely(hours < 0xc0))
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->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 ds1685_priv *rtc = dev_get_drvdata(dev);
u8 ctrlb, seconds, minutes, hours, mday;
int ret;
/* 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. */
ret = ds1685_rtc_check_mday(rtc, mday);
if (ret)
return ret;
/*
* 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;
if (unlikely(minutes >= 0xc0))
minutes = 0xff;
if (unlikely(hours >= 0xc0))
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 */
/**
* 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;
}
/* ----------------------------------------------------------------------- */
/* ----------------------------------------------------------------------- */
/* 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"
};
/**
* 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 ds1685_priv *rtc = dev_get_drvdata(dev);
u8 ctrla, ctrlb, ctrlc, ctrld, ctrl4a, ctrl4b, ssn[8];
char *model;
/* 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"
"Serial #\t: %8phC\n",
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"),
ssn);
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,
};
/* ----------------------------------------------------------------------- */
static int ds1685_nvram_read(void *priv, unsigned int pos, void *val,
size_t size)
{
struct ds1685_priv *rtc = priv;
ssize_t count;
unsigned long flags = 0;
u8 *buf = val;
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);
return 0;
}
static int ds1685_nvram_write(void *priv, unsigned int pos, void *val,
size_t size)
{
struct ds1685_priv *rtc = priv;
ssize_t count;
unsigned long flags = 0;
u8 *buf = val;
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 0;
}
/* ----------------------------------------------------------------------- */
/* SysFS interface */
/**
* 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 ds1685_priv *rtc = dev_get_drvdata(dev);
u8 ctrld;
ctrld = rtc->read(rtc, RTC_CTRL_D);
return sprintf(buf, "%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 ds1685_priv *rtc = dev_get_drvdata(dev);
u8 ctrl4a;
ds1685_rtc_switch_to_bank1(rtc);
ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
ds1685_rtc_switch_to_bank0(rtc);
return sprintf(buf, "%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 ds1685_priv *rtc = dev_get_drvdata(dev);
u8 ssn[8];
ds1685_rtc_switch_to_bank1(rtc);
ds1685_rtc_get_ssn(rtc, ssn);
ds1685_rtc_switch_to_bank0(rtc);
return sprintf(buf, "%8phC\n", ssn);
}
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,
};
/* ----------------------------------------------------------------------- */
/* 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;
struct nvmem_config nvmem_cfg = {
.name = "ds1685_nvram",
.size = NVRAM_TOTAL_SZ,
.reg_read = ds1685_nvram_read,
.reg_write = ds1685_nvram_write,
};
/* 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));
rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc_dev))
return PTR_ERR(rtc_dev);
rtc_dev->ops = &ds1685_rtc_ops;
/* Century bit is useless because leap year fails in 1900 and 2100 */
rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
rtc_dev->range_max = RTC_TIMESTAMP_END_2099;
/* 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;
/*
* 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);
ret = rtc_add_group(rtc_dev, &ds1685_rtc_sysfs_misc_grp);
if (ret)
return ret;
rtc_dev->nvram_old_abi = true;
nvmem_cfg.priv = rtc;
ret = rtc_nvmem_register(rtc_dev, &nvmem_cfg);
if (ret)
return ret;
return rtc_register_device(rtc_dev);
}
/**
* 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);
/* 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",
},
.probe = ds1685_rtc_probe,
.remove = ds1685_rtc_remove,
};
module_platform_driver(ds1685_rtc_driver);
/* ----------------------------------------------------------------------- */
/* ----------------------------------------------------------------------- */
/* Poweroff function */
/**
* ds1685_rtc_poweroff - uses the RTC chip to power the system off.
* @pdev: pointer to platform_device structure.
*/
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("platform device data not available, spinning forever ...\n");
while(1);
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. */
while(1);
unreachable();
}
}
EXPORT_SYMBOL(ds1685_rtc_poweroff);
/* ----------------------------------------------------------------------- */
MODULE_AUTHOR("Joshua Kinard <kumba@gentoo.org>");
MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd-electronics.com>");
MODULE_DESCRIPTION("Dallas/Maxim DS1685/DS1687-series RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rtc-ds1685");
