/* * rtc-ab-b5ze-s3 - Driver for Abracon AB-RTCMC-32.768Khz-B5ZE-S3 * I2C RTC / Alarm chip * * Copyright (C) 2014, Arnaud EBALARD <arno@natisbad.org> * * Detailed datasheet of the chip is available here: * * http://www.abracon.com/realtimeclock/AB-RTCMC-32.768kHz-B5ZE-S3-Application-Manual.pdf * * This work is based on ISL12057 driver (drivers/rtc/rtc-isl12057.c). * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/module.h> #include <linux/mutex.h> #include <linux/rtc.h> #include <linux/i2c.h> #include <linux/bcd.h> #include <linux/of.h> #include <linux/regmap.h> #include <linux/interrupt.h> #define DRV_NAME "rtc-ab-b5ze-s3" /* Control section */ #define ABB5ZES3_REG_CTRL1 0x00 /* Control 1 register */ #define ABB5ZES3_REG_CTRL1_CIE BIT(0) /* Pulse interrupt enable */ #define ABB5ZES3_REG_CTRL1_AIE BIT(1) /* Alarm interrupt enable */ #define ABB5ZES3_REG_CTRL1_SIE BIT(2) /* Second interrupt enable */ #define ABB5ZES3_REG_CTRL1_PM BIT(3) /* 24h/12h mode */ #define ABB5ZES3_REG_CTRL1_SR BIT(4) /* Software reset */ #define ABB5ZES3_REG_CTRL1_STOP BIT(5) /* RTC circuit enable */ #define ABB5ZES3_REG_CTRL1_CAP BIT(7) #define ABB5ZES3_REG_CTRL2 0x01 /* Control 2 register */ #define ABB5ZES3_REG_CTRL2_CTBIE BIT(0) /* Countdown timer B int. enable */ #define ABB5ZES3_REG_CTRL2_CTAIE BIT(1) /* Countdown timer A int. enable */ #define ABB5ZES3_REG_CTRL2_WTAIE BIT(2) /* Watchdog timer A int. enable */ #define ABB5ZES3_REG_CTRL2_AF BIT(3) /* Alarm interrupt status */ #define ABB5ZES3_REG_CTRL2_SF BIT(4) /* Second interrupt status */ #define ABB5ZES3_REG_CTRL2_CTBF BIT(5) /* Countdown timer B int. status */ #define ABB5ZES3_REG_CTRL2_CTAF BIT(6) /* Countdown timer A int. status */ #define ABB5ZES3_REG_CTRL2_WTAF BIT(7) /* Watchdog timer A int. status */ #define ABB5ZES3_REG_CTRL3 0x02 /* Control 3 register */ #define ABB5ZES3_REG_CTRL3_PM2 BIT(7) /* Power Management bit 2 */ #define ABB5ZES3_REG_CTRL3_PM1 BIT(6) /* Power Management bit 1 */ #define ABB5ZES3_REG_CTRL3_PM0 BIT(5) /* Power Management bit 0 */ #define ABB5ZES3_REG_CTRL3_BSF BIT(3) /* Battery switchover int. status */ #define ABB5ZES3_REG_CTRL3_BLF BIT(2) /* Battery low int. status */ #define ABB5ZES3_REG_CTRL3_BSIE BIT(1) /* Battery switchover int. enable */ #define ABB5ZES3_REG_CTRL3_BLIE BIT(0) /* Battery low int. enable */ #define ABB5ZES3_CTRL_SEC_LEN 3 /* RTC section */ #define ABB5ZES3_REG_RTC_SC 0x03 /* RTC Seconds register */ #define ABB5ZES3_REG_RTC_SC_OSC BIT(7) /* Clock integrity status */ #define ABB5ZES3_REG_RTC_MN 0x04 /* RTC Minutes register */ #define ABB5ZES3_REG_RTC_HR 0x05 /* RTC Hours register */ #define ABB5ZES3_REG_RTC_HR_PM BIT(5) /* RTC Hours PM bit */ #define ABB5ZES3_REG_RTC_DT 0x06 /* RTC Date register */ #define ABB5ZES3_REG_RTC_DW 0x07 /* RTC Day of the week register */ #define ABB5ZES3_REG_RTC_MO 0x08 /* RTC Month register */ #define ABB5ZES3_REG_RTC_YR 0x09 /* RTC Year register */ #define ABB5ZES3_RTC_SEC_LEN 7 /* Alarm section (enable bits are all active low) */ #define ABB5ZES3_REG_ALRM_MN 0x0A /* Alarm - minute register */ #define ABB5ZES3_REG_ALRM_MN_AE BIT(7) /* Minute enable */ #define ABB5ZES3_REG_ALRM_HR 0x0B /* Alarm - hours register */ #define ABB5ZES3_REG_ALRM_HR_AE BIT(7) /* Hour enable */ #define ABB5ZES3_REG_ALRM_DT 0x0C /* Alarm - date register */ #define ABB5ZES3_REG_ALRM_DT_AE BIT(7) /* Date (day of the month) enable */ #define ABB5ZES3_REG_ALRM_DW 0x0D /* Alarm - day of the week reg. */ #define ABB5ZES3_REG_ALRM_DW_AE BIT(7) /* Day of the week enable */ #define ABB5ZES3_ALRM_SEC_LEN 4 /* Frequency offset section */ #define ABB5ZES3_REG_FREQ_OF 0x0E /* Frequency offset register */ #define ABB5ZES3_REG_FREQ_OF_MODE 0x0E /* Offset mode: 2 hours / minute */ /* CLOCKOUT section */ #define ABB5ZES3_REG_TIM_CLK 0x0F /* Timer & Clockout register */ #define ABB5ZES3_REG_TIM_CLK_TAM BIT(7) /* Permanent/pulsed timer A/int. 2 */ #define ABB5ZES3_REG_TIM_CLK_TBM BIT(6) /* Permanent/pulsed timer B */ #define ABB5ZES3_REG_TIM_CLK_COF2 BIT(5) /* Clkout Freq bit 2 */ #define ABB5ZES3_REG_TIM_CLK_COF1 BIT(4) /* Clkout Freq bit 1 */ #define ABB5ZES3_REG_TIM_CLK_COF0 BIT(3) /* Clkout Freq bit 0 */ #define ABB5ZES3_REG_TIM_CLK_TAC1 BIT(2) /* Timer A: - 01 : countdown */ #define ABB5ZES3_REG_TIM_CLK_TAC0 BIT(1) /* - 10 : timer */ #define ABB5ZES3_REG_TIM_CLK_TBC BIT(0) /* Timer B enable */ /* Timer A Section */ #define ABB5ZES3_REG_TIMA_CLK 0x10 /* Timer A clock register */ #define ABB5ZES3_REG_TIMA_CLK_TAQ2 BIT(2) /* Freq bit 2 */ #define ABB5ZES3_REG_TIMA_CLK_TAQ1 BIT(1) /* Freq bit 1 */ #define ABB5ZES3_REG_TIMA_CLK_TAQ0 BIT(0) /* Freq bit 0 */ #define ABB5ZES3_REG_TIMA 0x11 /* Timer A register */ #define ABB5ZES3_TIMA_SEC_LEN 2 /* Timer B Section */ #define ABB5ZES3_REG_TIMB_CLK 0x12 /* Timer B clock register */ #define ABB5ZES3_REG_TIMB_CLK_TBW2 BIT(6) #define ABB5ZES3_REG_TIMB_CLK_TBW1 BIT(5) #define ABB5ZES3_REG_TIMB_CLK_TBW0 BIT(4) #define ABB5ZES3_REG_TIMB_CLK_TAQ2 BIT(2) #define ABB5ZES3_REG_TIMB_CLK_TAQ1 BIT(1) #define ABB5ZES3_REG_TIMB_CLK_TAQ0 BIT(0) #define ABB5ZES3_REG_TIMB 0x13 /* Timer B register */ #define ABB5ZES3_TIMB_SEC_LEN 2 #define ABB5ZES3_MEM_MAP_LEN 0x14 struct abb5zes3_rtc_data { struct rtc_device *rtc; struct regmap *regmap; struct mutex lock; int irq; bool battery_low; bool timer_alarm; /* current alarm is via timer A */ }; /* * Try and match register bits w/ fixed null values to see whether we * are dealing with an ABB5ZES3. Note: this function is called early * during init and hence does need mutex protection. */ static int abb5zes3_i2c_validate_chip(struct regmap *regmap) { u8 regs[ABB5ZES3_MEM_MAP_LEN]; static const u8 mask[ABB5ZES3_MEM_MAP_LEN] = { 0x00, 0x00, 0x10, 0x00, 0x80, 0xc0, 0xc0, 0xf8, 0xe0, 0x00, 0x00, 0x40, 0x40, 0x78, 0x00, 0x00, 0xf8, 0x00, 0x88, 0x00 }; int ret, i; ret = regmap_bulk_read(regmap, 0, regs, ABB5ZES3_MEM_MAP_LEN); if (ret) return ret; for (i = 0; i < ABB5ZES3_MEM_MAP_LEN; ++i) { if (regs[i] & mask[i]) /* check if bits are cleared */ return -ENODEV; } return 0; } /* Clear alarm status bit. */ static int _abb5zes3_rtc_clear_alarm(struct device *dev) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); int ret; ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL2, ABB5ZES3_REG_CTRL2_AF, 0); if (ret) dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret); return ret; } /* Enable or disable alarm (i.e. alarm interrupt generation) */ static int _abb5zes3_rtc_update_alarm(struct device *dev, bool enable) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); int ret; ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL1, ABB5ZES3_REG_CTRL1_AIE, enable ? ABB5ZES3_REG_CTRL1_AIE : 0); if (ret) dev_err(dev, "%s: writing alarm INT failed (%d)\n", __func__, ret); return ret; } /* Enable or disable timer (watchdog timer A interrupt generation) */ static int _abb5zes3_rtc_update_timer(struct device *dev, bool enable) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); int ret; ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL2, ABB5ZES3_REG_CTRL2_WTAIE, enable ? ABB5ZES3_REG_CTRL2_WTAIE : 0); if (ret) dev_err(dev, "%s: writing timer INT failed (%d)\n", __func__, ret); return ret; } /* * Note: we only read, so regmap inner lock protection is sufficient, i.e. * we do not need driver's main lock protection. */ static int _abb5zes3_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); u8 regs[ABB5ZES3_REG_RTC_SC + ABB5ZES3_RTC_SEC_LEN]; int ret; /* * As we need to read CTRL1 register anyway to access 24/12h * mode bit, we do a single bulk read of both control and RTC * sections (they are consecutive). This also ease indexing * of register values after bulk read. */ ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_CTRL1, regs, sizeof(regs)); if (ret) { dev_err(dev, "%s: reading RTC time failed (%d)\n", __func__, ret); goto err; } /* If clock integrity is not guaranteed, do not return a time value */ if (regs[ABB5ZES3_REG_RTC_SC] & ABB5ZES3_REG_RTC_SC_OSC) { ret = -ENODATA; goto err; } tm->tm_sec = bcd2bin(regs[ABB5ZES3_REG_RTC_SC] & 0x7F); tm->tm_min = bcd2bin(regs[ABB5ZES3_REG_RTC_MN]); if (regs[ABB5ZES3_REG_CTRL1] & ABB5ZES3_REG_CTRL1_PM) { /* 12hr mode */ tm->tm_hour = bcd2bin(regs[ABB5ZES3_REG_RTC_HR] & 0x1f); if (regs[ABB5ZES3_REG_RTC_HR] & ABB5ZES3_REG_RTC_HR_PM) /* PM */ tm->tm_hour += 12; } else { /* 24hr mode */ tm->tm_hour = bcd2bin(regs[ABB5ZES3_REG_RTC_HR]); } tm->tm_mday = bcd2bin(regs[ABB5ZES3_REG_RTC_DT]); tm->tm_wday = bcd2bin(regs[ABB5ZES3_REG_RTC_DW]); tm->tm_mon = bcd2bin(regs[ABB5ZES3_REG_RTC_MO]) - 1; /* starts at 1 */ tm->tm_year = bcd2bin(regs[ABB5ZES3_REG_RTC_YR]) + 100; ret = rtc_valid_tm(tm); err: return ret; } static int abb5zes3_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); u8 regs[ABB5ZES3_REG_RTC_SC + ABB5ZES3_RTC_SEC_LEN]; int ret; /* * Year register is 8-bit wide and bcd-coded, i.e records values * between 0 and 99. tm_year is an offset from 1900 and we are * interested in the 2000-2099 range, so any value less than 100 * is invalid. */ if (tm->tm_year < 100) return -EINVAL; regs[ABB5ZES3_REG_RTC_SC] = bin2bcd(tm->tm_sec); /* MSB=0 clears OSC */ regs[ABB5ZES3_REG_RTC_MN] = bin2bcd(tm->tm_min); regs[ABB5ZES3_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */ regs[ABB5ZES3_REG_RTC_DT] = bin2bcd(tm->tm_mday); regs[ABB5ZES3_REG_RTC_DW] = bin2bcd(tm->tm_wday); regs[ABB5ZES3_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1); regs[ABB5ZES3_REG_RTC_YR] = bin2bcd(tm->tm_year - 100); mutex_lock(&data->lock); ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_RTC_SC, regs + ABB5ZES3_REG_RTC_SC, ABB5ZES3_RTC_SEC_LEN); mutex_unlock(&data->lock); return ret; } /* * Set provided TAQ and Timer A registers (TIMA_CLK and TIMA) based on * given number of seconds. */ static inline void sec_to_timer_a(u8 secs, u8 *taq, u8 *timer_a) { *taq = ABB5ZES3_REG_TIMA_CLK_TAQ1; /* 1Hz */ *timer_a = secs; } /* * Return current number of seconds in Timer A. As we only use * timer A with a 1Hz freq, this is what we expect to have. */ static inline int sec_from_timer_a(u8 *secs, u8 taq, u8 timer_a) { if (taq != ABB5ZES3_REG_TIMA_CLK_TAQ1) /* 1Hz */ return -EINVAL; *secs = timer_a; return 0; } /* * Read alarm currently configured via a watchdog timer using timer A. This * is done by reading current RTC time and adding remaining timer time. */ static int _abb5zes3_rtc_read_timer(struct device *dev, struct rtc_wkalrm *alarm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); struct rtc_time rtc_tm, *alarm_tm = &alarm->time; u8 regs[ABB5ZES3_TIMA_SEC_LEN + 1]; unsigned long rtc_secs; unsigned int reg; u8 timer_secs; int ret; /* * Instead of doing two separate calls, because they are consecutive, * we grab both clockout register and Timer A section. The latter is * used to decide if timer A is enabled (as a watchdog timer). */ ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_TIM_CLK, regs, ABB5ZES3_TIMA_SEC_LEN + 1); if (ret) { dev_err(dev, "%s: reading Timer A section failed (%d)\n", __func__, ret); goto err; } /* get current time ... */ ret = _abb5zes3_rtc_read_time(dev, &rtc_tm); if (ret) goto err; /* ... convert to seconds ... */ ret = rtc_tm_to_time(&rtc_tm, &rtc_secs); if (ret) goto err; /* ... add remaining timer A time ... */ ret = sec_from_timer_a(&timer_secs, regs[1], regs[2]); if (ret) goto err; /* ... and convert back. */ rtc_time_to_tm(rtc_secs + timer_secs, alarm_tm); ret = regmap_read(data->regmap, ABB5ZES3_REG_CTRL2, ®); if (ret) { dev_err(dev, "%s: reading ctrl reg failed (%d)\n", __func__, ret); goto err; } alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL2_WTAIE); err: return ret; } /* Read alarm currently configured via a RTC alarm registers. */ static int _abb5zes3_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); struct rtc_time rtc_tm, *alarm_tm = &alarm->time; unsigned long rtc_secs, alarm_secs; u8 regs[ABB5ZES3_ALRM_SEC_LEN]; unsigned int reg; int ret; ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_ALRM_MN, regs, ABB5ZES3_ALRM_SEC_LEN); if (ret) { dev_err(dev, "%s: reading alarm section failed (%d)\n", __func__, ret); goto err; } alarm_tm->tm_sec = 0; alarm_tm->tm_min = bcd2bin(regs[0] & 0x7f); alarm_tm->tm_hour = bcd2bin(regs[1] & 0x3f); alarm_tm->tm_mday = bcd2bin(regs[2] & 0x3f); alarm_tm->tm_wday = -1; /* * The alarm section does not store year/month. We use the ones in rtc * section as a basis and increment month and then year if needed to get * alarm after current time. */ ret = _abb5zes3_rtc_read_time(dev, &rtc_tm); if (ret) goto err; alarm_tm->tm_year = rtc_tm.tm_year; alarm_tm->tm_mon = rtc_tm.tm_mon; ret = rtc_tm_to_time(&rtc_tm, &rtc_secs); if (ret) goto err; ret = rtc_tm_to_time(alarm_tm, &alarm_secs); if (ret) goto err; if (alarm_secs < rtc_secs) { if (alarm_tm->tm_mon == 11) { alarm_tm->tm_mon = 0; alarm_tm->tm_year += 1; } else { alarm_tm->tm_mon += 1; } } ret = regmap_read(data->regmap, ABB5ZES3_REG_CTRL1, ®); if (ret) { dev_err(dev, "%s: reading ctrl reg failed (%d)\n", __func__, ret); goto err; } alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL1_AIE); err: return ret; } /* * As the Alarm mechanism supported by the chip is only accurate to the * minute, we use the watchdog timer mechanism provided by timer A * (up to 256 seconds w/ a second accuracy) for low alarm values (below * 4 minutes). Otherwise, we use the common alarm mechanism provided * by the chip. In order for that to work, we keep track of currently * configured timer type via 'timer_alarm' flag in our private data * structure. */ static int abb5zes3_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); int ret; mutex_lock(&data->lock); if (data->timer_alarm) ret = _abb5zes3_rtc_read_timer(dev, alarm); else ret = _abb5zes3_rtc_read_alarm(dev, alarm); mutex_unlock(&data->lock); return ret; } /* * Set alarm using chip alarm mechanism. It is only accurate to the * minute (not the second). The function expects alarm interrupt to * be disabled. */ static int _abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); struct rtc_time *alarm_tm = &alarm->time; unsigned long rtc_secs, alarm_secs; u8 regs[ABB5ZES3_ALRM_SEC_LEN]; struct rtc_time rtc_tm; int ret, enable = 1; ret = _abb5zes3_rtc_read_time(dev, &rtc_tm); if (ret) goto err; ret = rtc_tm_to_time(&rtc_tm, &rtc_secs); if (ret) goto err; ret = rtc_tm_to_time(alarm_tm, &alarm_secs); if (ret) goto err; /* If alarm time is before current time, disable the alarm */ if (!alarm->enabled || alarm_secs <= rtc_secs) { enable = 0; } else { /* * Chip only support alarms up to one month in the future. Let's * return an error if we get something after that limit. * Comparison is done by incrementing rtc_tm month field by one * and checking alarm value is still below. */ if (rtc_tm.tm_mon == 11) { /* handle year wrapping */ rtc_tm.tm_mon = 0; rtc_tm.tm_year += 1; } else { rtc_tm.tm_mon += 1; } ret = rtc_tm_to_time(&rtc_tm, &rtc_secs); if (ret) goto err; if (alarm_secs > rtc_secs) { dev_err(dev, "%s: alarm maximum is one month in the " "future (%d)\n", __func__, ret); ret = -EINVAL; goto err; } } /* * Program all alarm registers but DW one. For each register, setting * MSB to 0 enables associated alarm. */ regs[0] = bin2bcd(alarm_tm->tm_min) & 0x7f; regs[1] = bin2bcd(alarm_tm->tm_hour) & 0x3f; regs[2] = bin2bcd(alarm_tm->tm_mday) & 0x3f; regs[3] = ABB5ZES3_REG_ALRM_DW_AE; /* do not match day of the week */ ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_ALRM_MN, regs, ABB5ZES3_ALRM_SEC_LEN); if (ret < 0) { dev_err(dev, "%s: writing ALARM section failed (%d)\n", __func__, ret); goto err; } /* Record currently configured alarm is not a timer */ data->timer_alarm = 0; /* Enable or disable alarm interrupt generation */ ret = _abb5zes3_rtc_update_alarm(dev, enable); err: return ret; } /* * Set alarm using timer watchdog (via timer A) mechanism. The function expects * timer A interrupt to be disabled. */ static int _abb5zes3_rtc_set_timer(struct device *dev, struct rtc_wkalrm *alarm, u8 secs) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); u8 regs[ABB5ZES3_TIMA_SEC_LEN]; u8 mask = ABB5ZES3_REG_TIM_CLK_TAC0 | ABB5ZES3_REG_TIM_CLK_TAC1; int ret = 0; /* Program given number of seconds to Timer A registers */ sec_to_timer_a(secs, ®s[0], ®s[1]); ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_TIMA_CLK, regs, ABB5ZES3_TIMA_SEC_LEN); if (ret < 0) { dev_err(dev, "%s: writing timer section failed\n", __func__); goto err; } /* Configure Timer A as a watchdog timer */ ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_TIM_CLK, mask, ABB5ZES3_REG_TIM_CLK_TAC1); if (ret) dev_err(dev, "%s: failed to update timer\n", __func__); /* Record currently configured alarm is a timer */ data->timer_alarm = 1; /* Enable or disable timer interrupt generation */ ret = _abb5zes3_rtc_update_timer(dev, alarm->enabled); err: return ret; } /* * The chip has an alarm which is only accurate to the minute. In order to * handle alarms below that limit, we use the watchdog timer function of * timer A. More precisely, the timer method is used for alarms below 240 * seconds. */ static int abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); struct rtc_time *alarm_tm = &alarm->time; unsigned long rtc_secs, alarm_secs; struct rtc_time rtc_tm; int ret; mutex_lock(&data->lock); ret = _abb5zes3_rtc_read_time(dev, &rtc_tm); if (ret) goto err; ret = rtc_tm_to_time(&rtc_tm, &rtc_secs); if (ret) goto err; ret = rtc_tm_to_time(alarm_tm, &alarm_secs); if (ret) goto err; /* Let's first disable both the alarm and the timer interrupts */ ret = _abb5zes3_rtc_update_alarm(dev, false); if (ret < 0) { dev_err(dev, "%s: unable to disable alarm (%d)\n", __func__, ret); goto err; } ret = _abb5zes3_rtc_update_timer(dev, false); if (ret < 0) { dev_err(dev, "%s: unable to disable timer (%d)\n", __func__, ret); goto err; } data->timer_alarm = 0; /* * Let's now configure the alarm; if we are expected to ring in * more than 240s, then we setup an alarm. Otherwise, a timer. */ if ((alarm_secs > rtc_secs) && ((alarm_secs - rtc_secs) <= 240)) ret = _abb5zes3_rtc_set_timer(dev, alarm, alarm_secs - rtc_secs); else ret = _abb5zes3_rtc_set_alarm(dev, alarm); err: mutex_unlock(&data->lock); if (ret) dev_err(dev, "%s: unable to configure alarm (%d)\n", __func__, ret); return ret; } /* Enable or disable battery low irq generation */ static inline int _abb5zes3_rtc_battery_low_irq_enable(struct regmap *regmap, bool enable) { return regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3, ABB5ZES3_REG_CTRL3_BLIE, enable ? ABB5ZES3_REG_CTRL3_BLIE : 0); } /* * Check current RTC status and enable/disable what needs to be. Return 0 if * everything went ok and a negative value upon error. Note: this function * is called early during init and hence does need mutex protection. */ static int abb5zes3_rtc_check_setup(struct device *dev) { struct abb5zes3_rtc_data *data = dev_get_drvdata(dev); struct regmap *regmap = data->regmap; unsigned int reg; int ret; u8 mask; /* * By default, the devices generates a 32.768KHz signal on IRQ#1 pin. It * is disabled here to prevent polluting the interrupt line and * uselessly triggering the IRQ handler we install for alarm and battery * low events. Note: this is done before clearing int. status below * in this function. * We also disable all timers and set timer interrupt to permanent (not * pulsed). */ mask = (ABB5ZES3_REG_TIM_CLK_TBC | ABB5ZES3_REG_TIM_CLK_TAC0 | ABB5ZES3_REG_TIM_CLK_TAC1 | ABB5ZES3_REG_TIM_CLK_COF0 | ABB5ZES3_REG_TIM_CLK_COF1 | ABB5ZES3_REG_TIM_CLK_COF2 | ABB5ZES3_REG_TIM_CLK_TBM | ABB5ZES3_REG_TIM_CLK_TAM); ret = regmap_update_bits(regmap, ABB5ZES3_REG_TIM_CLK, mask, ABB5ZES3_REG_TIM_CLK_COF0 | ABB5ZES3_REG_TIM_CLK_COF1 | ABB5ZES3_REG_TIM_CLK_COF2); if (ret < 0) { dev_err(dev, "%s: unable to initialize clkout register (%d)\n", __func__, ret); return ret; } /* * Each component of the alarm (MN, HR, DT, DW) can be enabled/disabled * individually by clearing/setting MSB of each associated register. So, * we set all alarm enable bits to disable current alarm setting. */ mask = (ABB5ZES3_REG_ALRM_MN_AE | ABB5ZES3_REG_ALRM_HR_AE | ABB5ZES3_REG_ALRM_DT_AE | ABB5ZES3_REG_ALRM_DW_AE); ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, mask); if (ret < 0) { dev_err(dev, "%s: unable to disable alarm setting (%d)\n", __func__, ret); return ret; } /* Set Control 1 register (RTC enabled, 24hr mode, all int. disabled) */ mask = (ABB5ZES3_REG_CTRL1_CIE | ABB5ZES3_REG_CTRL1_AIE | ABB5ZES3_REG_CTRL1_SIE | ABB5ZES3_REG_CTRL1_PM | ABB5ZES3_REG_CTRL1_CAP | ABB5ZES3_REG_CTRL1_STOP); ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL1, mask, 0); if (ret < 0) { dev_err(dev, "%s: unable to initialize CTRL1 register (%d)\n", __func__, ret); return ret; } /* * Set Control 2 register (timer int. disabled, alarm status cleared). * WTAF is read-only and cleared automatically by reading the register. */ mask = (ABB5ZES3_REG_CTRL2_CTBIE | ABB5ZES3_REG_CTRL2_CTAIE | ABB5ZES3_REG_CTRL2_WTAIE | ABB5ZES3_REG_CTRL2_AF | ABB5ZES3_REG_CTRL2_SF | ABB5ZES3_REG_CTRL2_CTBF | ABB5ZES3_REG_CTRL2_CTAF); ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, 0); if (ret < 0) { dev_err(dev, "%s: unable to initialize CTRL2 register (%d)\n", __func__, ret); return ret; } /* * Enable battery low detection function and battery switchover function * (standard mode). Disable associated interrupts. Clear battery * switchover flag but not battery low flag. The latter is checked * later below. */ mask = (ABB5ZES3_REG_CTRL3_PM0 | ABB5ZES3_REG_CTRL3_PM1 | ABB5ZES3_REG_CTRL3_PM2 | ABB5ZES3_REG_CTRL3_BLIE | ABB5ZES3_REG_CTRL3_BSIE| ABB5ZES3_REG_CTRL3_BSF); ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3, mask, 0); if (ret < 0) { dev_err(dev, "%s: unable to initialize CTRL3 register (%d)\n", __func__, ret); return ret; } /* Check oscillator integrity flag */ ret = regmap_read(regmap, ABB5ZES3_REG_RTC_SC, ®); if (ret < 0) { dev_err(dev, "%s: unable to read osc. integrity flag (%d)\n", __func__, ret); return ret; } if (reg & ABB5ZES3_REG_RTC_SC_OSC) { dev_err(dev, "clock integrity not guaranteed. Osc. has stopped " "or has been interrupted.\n"); dev_err(dev, "change battery (if not already done) and " "then set time to reset osc. failure flag.\n"); } /* * Check battery low flag at startup: this allows reporting battery * is low at startup when IRQ line is not connected. Note: we record * current status to avoid reenabling this interrupt later in probe * function if battery is low. */ ret = regmap_read(regmap, ABB5ZES3_REG_CTRL3, ®); if (ret < 0) { dev_err(dev, "%s: unable to read battery low flag (%d)\n", __func__, ret); return ret; } data->battery_low = reg & ABB5ZES3_REG_CTRL3_BLF; if (data->battery_low) { dev_err(dev, "RTC battery is low; please, consider " "changing it!\n"); ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, false); if (ret) dev_err(dev, "%s: disabling battery low interrupt " "generation failed (%d)\n", __func__, ret); } return ret; } static int abb5zes3_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) { struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev); int ret = 0; if (rtc_data->irq) { mutex_lock(&rtc_data->lock); if (rtc_data->timer_alarm) ret = _abb5zes3_rtc_update_timer(dev, enable); else ret = _abb5zes3_rtc_update_alarm(dev, enable); mutex_unlock(&rtc_data->lock); } return ret; } static irqreturn_t _abb5zes3_rtc_interrupt(int irq, void *data) { struct i2c_client *client = data; struct device *dev = &client->dev; struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev); struct rtc_device *rtc = rtc_data->rtc; u8 regs[ABB5ZES3_CTRL_SEC_LEN]; int ret, handled = IRQ_NONE; ret = regmap_bulk_read(rtc_data->regmap, 0, regs, ABB5ZES3_CTRL_SEC_LEN); if (ret) { dev_err(dev, "%s: unable to read control section (%d)!\n", __func__, ret); return handled; } /* * Check battery low detection flag and disable battery low interrupt * generation if flag is set (interrupt can only be cleared when * battery is replaced). */ if (regs[ABB5ZES3_REG_CTRL3] & ABB5ZES3_REG_CTRL3_BLF) { dev_err(dev, "RTC battery is low; please change it!\n"); _abb5zes3_rtc_battery_low_irq_enable(rtc_data->regmap, false); handled = IRQ_HANDLED; } /* Check alarm flag */ if (regs[ABB5ZES3_REG_CTRL2] & ABB5ZES3_REG_CTRL2_AF) { dev_dbg(dev, "RTC alarm!\n"); rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF); /* Acknowledge and disable the alarm */ _abb5zes3_rtc_clear_alarm(dev); _abb5zes3_rtc_update_alarm(dev, 0); handled = IRQ_HANDLED; } /* Check watchdog Timer A flag */ if (regs[ABB5ZES3_REG_CTRL2] & ABB5ZES3_REG_CTRL2_WTAF) { dev_dbg(dev, "RTC timer!\n"); rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF); /* * Acknowledge and disable the alarm. Note: WTAF * flag had been cleared when reading CTRL2 */ _abb5zes3_rtc_update_timer(dev, 0); rtc_data->timer_alarm = 0; handled = IRQ_HANDLED; } return handled; } static const struct rtc_class_ops rtc_ops = { .read_time = _abb5zes3_rtc_read_time, .set_time = abb5zes3_rtc_set_time, .read_alarm = abb5zes3_rtc_read_alarm, .set_alarm = abb5zes3_rtc_set_alarm, .alarm_irq_enable = abb5zes3_rtc_alarm_irq_enable, }; static struct regmap_config abb5zes3_rtc_regmap_config = { .reg_bits = 8, .val_bits = 8, }; static int abb5zes3_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct abb5zes3_rtc_data *data = NULL; struct device *dev = &client->dev; struct regmap *regmap; int ret; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) { ret = -ENODEV; goto err; } regmap = devm_regmap_init_i2c(client, &abb5zes3_rtc_regmap_config); if (IS_ERR(regmap)) { ret = PTR_ERR(regmap); dev_err(dev, "%s: regmap allocation failed: %d\n", __func__, ret); goto err; } ret = abb5zes3_i2c_validate_chip(regmap); if (ret) goto err; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) { ret = -ENOMEM; goto err; } mutex_init(&data->lock); data->regmap = regmap; dev_set_drvdata(dev, data); ret = abb5zes3_rtc_check_setup(dev); if (ret) goto err; if (client->irq > 0) { ret = devm_request_threaded_irq(dev, client->irq, NULL, _abb5zes3_rtc_interrupt, IRQF_SHARED|IRQF_ONESHOT, DRV_NAME, client); if (!ret) { device_init_wakeup(dev, true); data->irq = client->irq; dev_dbg(dev, "%s: irq %d used by RTC\n", __func__, client->irq); } else { dev_err(dev, "%s: irq %d unavailable (%d)\n", __func__, client->irq, ret); goto err; } } data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops, THIS_MODULE); ret = PTR_ERR_OR_ZERO(data->rtc); if (ret) { dev_err(dev, "%s: unable to register RTC device (%d)\n", __func__, ret); goto err; } /* Enable battery low detection interrupt if battery not already low */ if (!data->battery_low && data->irq) { ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, true); if (ret) { dev_err(dev, "%s: enabling battery low interrupt " "generation failed (%d)\n", __func__, ret); goto err; } } err: if (ret && data && data->irq) device_init_wakeup(dev, false); return ret; } static int abb5zes3_remove(struct i2c_client *client) { struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(&client->dev); if (rtc_data->irq > 0) device_init_wakeup(&client->dev, false); return 0; } #ifdef CONFIG_PM_SLEEP static int abb5zes3_rtc_suspend(struct device *dev) { struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev); if (device_may_wakeup(dev)) return enable_irq_wake(rtc_data->irq); return 0; } static int abb5zes3_rtc_resume(struct device *dev) { struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev); if (device_may_wakeup(dev)) return disable_irq_wake(rtc_data->irq); return 0; } #endif static SIMPLE_DEV_PM_OPS(abb5zes3_rtc_pm_ops, abb5zes3_rtc_suspend, abb5zes3_rtc_resume); #ifdef CONFIG_OF static const struct of_device_id abb5zes3_dt_match[] = { { .compatible = "abracon,abb5zes3" }, { }, }; #endif static const struct i2c_device_id abb5zes3_id[] = { { "abb5zes3", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, abb5zes3_id); static struct i2c_driver abb5zes3_driver = { .driver = { .name = DRV_NAME, .owner = THIS_MODULE, .pm = &abb5zes3_rtc_pm_ops, .of_match_table = of_match_ptr(abb5zes3_dt_match), }, .probe = abb5zes3_probe, .remove = abb5zes3_remove, .id_table = abb5zes3_id, }; module_i2c_driver(abb5zes3_driver); MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>"); MODULE_DESCRIPTION("Abracon AB-RTCMC-32.768kHz-B5ZE-S3 RTC/Alarm driver"); MODULE_LICENSE("GPL");