// 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 . * Copyright (C) 2009 Matthias Fuchs . * * 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 #include #include #include #include #include #include #include #ifdef CONFIG_PROC_FS #include #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 void 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))); } /* * 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 "); MODULE_AUTHOR("Matthias Fuchs "); MODULE_DESCRIPTION("Dallas/Maxim DS1685/DS1687-series RTC driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:rtc-ds1685");