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Diffstat (limited to 'drivers/rtc/rtc-ds1685.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1685.c | 1445 |
1 files changed, 1445 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c new file mode 100644 index 000000000..db7216f14 --- /dev/null +++ b/drivers/rtc/rtc-ds1685.c @@ -0,0 +1,1445 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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. + */ + +#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 + * all registers are mapped in CPU address space + */ + +/** + * 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))); +} +/* ----------------------------------------------------------------------- */ + +/* + * Indirect read/write functions + * access happens via address and data register mapped in CPU address space + */ + +/** + * ds1685_indirect_read - read a value from an rtc register. + * @rtc: pointer to the ds1685 rtc structure. + * @reg: the register address to read. + */ +static u8 +ds1685_indirect_read(struct ds1685_priv *rtc, int reg) +{ + writeb(reg, rtc->regs); + return readb(rtc->data); +} + +/** + * ds1685_indirect_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_indirect_write(struct ds1685_priv *rtc, int reg, u8 value) +{ + writeb(reg, rtc->regs); + writeb(value, rtc->data); +} + +/* ----------------------------------------------------------------------- */ +/* 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_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)); + + /* Switch to Bank 1 */ + ds1685_rtc_switch_to_bank1(rtc); + + /* 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(); +} + +/** + * 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_bank0(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_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 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); + 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); + + /* 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); + + return 0; +} +/* ----------------------------------------------------------------------- */ + + +/* ----------------------------------------------------------------------- */ +/* IRQ handler */ + +/** + * ds1685_rtc_extended_irq - take care of extended interrupts + * @rtc: pointer to the ds1685 rtc structure. + * @pdev: platform device pointer. + */ +static void +ds1685_rtc_extended_irq(struct ds1685_priv *rtc, struct platform_device *pdev) +{ + u8 ctrl4a, ctrl4b; + + 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); +} + +/** + * 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; + + rtc_lock(rtc->dev); + + /* Ctrlb holds the interrupt-enable bits and ctrlc the flag bits. */ + 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++; + } + } else { + /* + * One of the "extended" interrupts was received that + * is not recognized by the RTC core. + */ + ds1685_rtc_extended_irq(rtc, pdev); + } + } + rtc_update_irq(rtc->dev, num_irqs, events); + rtc_unlock(rtc->dev); + + return events ? IRQ_HANDLED : IRQ_NONE; +} +/* ----------------------------------------------------------------------- */ + + +/* ----------------------------------------------------------------------- */ +/* 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, 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); + 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; + struct mutex *rtc_mutex = &rtc->dev->ops_lock; + ssize_t count; + u8 *buf = val; + int err; + + err = mutex_lock_interruptible(rtc_mutex); + if (err) + return err; + + 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 */ + mutex_unlock(rtc_mutex); + + return 0; +} + +static int ds1685_nvram_write(void *priv, unsigned int pos, void *val, + size_t size) +{ + struct ds1685_priv *rtc = priv; + struct mutex *rtc_mutex = &rtc->dev->ops_lock; + ssize_t count; + u8 *buf = val; + int err; + + err = mutex_lock_interruptible(rtc_mutex); + if (err) + return err; + + 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 */ + mutex_unlock(rtc_mutex); + + 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->parent); + 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->parent); + 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->parent); + 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 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; + + /* Setup resources and access functions */ + switch (pdata->access_type) { + case ds1685_reg_direct: + rtc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rtc->regs)) + return PTR_ERR(rtc->regs); + rtc->read = ds1685_read; + rtc->write = ds1685_write; + break; + case ds1685_reg_indirect: + rtc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rtc->regs)) + return PTR_ERR(rtc->regs); + rtc->data = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(rtc->data)) + return PTR_ERR(rtc->data); + rtc->read = ds1685_indirect_read; + rtc->write = ds1685_indirect_write; + break; + } + + if (!rtc->read || !rtc->write) + return -ENXIO; + + /* Get the register step size. */ + if (pdata->regstep > 0) + rtc->regstep = pdata->regstep; + else + rtc->regstep = 1; + + /* 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; + + /* set the driver data. */ + 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) + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc_dev->features); + + 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. + */ + rtc->irq_num = platform_get_irq(pdev, 0); + if (rtc->irq_num <= 0) { + clear_bit(RTC_FEATURE_ALARM, rtc_dev->features); + } else { + /* Request an IRQ. */ + ret = devm_request_threaded_irq(&pdev->dev, rtc->irq_num, + NULL, ds1685_rtc_irq_handler, + IRQF_SHARED | IRQF_ONESHOT, + 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; + } + } + + /* Setup complete. */ + ds1685_rtc_switch_to_bank0(rtc); + + ret = rtc_add_group(rtc_dev, &ds1685_rtc_sysfs_misc_grp); + if (ret) + return ret; + + nvmem_cfg.priv = rtc; + ret = devm_rtc_nvmem_register(rtc_dev, &nvmem_cfg); + if (ret) + return ret; + + return devm_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))); + + 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->irq_num) + 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_GPL(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"); |