diff options
Diffstat (limited to 'drivers/rtc/rtc-bd70528.c')
| -rw-r--r-- | drivers/rtc/rtc-bd70528.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bd70528.c b/drivers/rtc/rtc-bd70528.c new file mode 100644 index 000000000000..f9bdd555e1a2 --- /dev/null +++ b/drivers/rtc/rtc-bd70528.c @@ -0,0 +1,500 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// +// Copyright (C) 2018 ROHM Semiconductors +// +// RTC driver for ROHM BD70528 PMIC + +#include <linux/bcd.h> +#include <linux/mfd/rohm-bd70528.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/rtc.h> + +/* + * We read regs RTC_SEC => RTC_YEAR + * this struct is ordered according to chip registers. + * Keep it u8 only to avoid padding issues. + */ +struct bd70528_rtc_day { + u8 sec; + u8 min; + u8 hour; +} __packed; + +struct bd70528_rtc_data { + struct bd70528_rtc_day time; + u8 week; + u8 day; + u8 month; + u8 year; +} __packed; + +struct bd70528_rtc_wake { + struct bd70528_rtc_day time; + u8 ctrl; +} __packed; + +struct bd70528_rtc_alm { + struct bd70528_rtc_data data; + u8 alm_mask; + u8 alm_repeat; +} __packed; + +struct bd70528_rtc { + struct rohm_regmap_dev *mfd; + struct device *dev; +}; + +static int bd70528_set_wake(struct rohm_regmap_dev *bd70528, + int enable, int *old_state) +{ + int ret; + unsigned int ctrl_reg; + + ret = regmap_read(bd70528->regmap, BD70528_REG_WAKE_EN, &ctrl_reg); + if (ret) + return ret; + + if (old_state) { + if (ctrl_reg & BD70528_MASK_WAKE_EN) + *old_state |= BD70528_WAKE_STATE_BIT; + else + *old_state &= ~BD70528_WAKE_STATE_BIT; + + if (!enable == !(*old_state & BD70528_WAKE_STATE_BIT)) + return 0; + } + + if (enable) + ctrl_reg |= BD70528_MASK_WAKE_EN; + else + ctrl_reg &= ~BD70528_MASK_WAKE_EN; + + return regmap_write(bd70528->regmap, BD70528_REG_WAKE_EN, + ctrl_reg); +} + +static int bd70528_set_elapsed_tmr(struct rohm_regmap_dev *bd70528, + int enable, int *old_state) +{ + int ret; + unsigned int ctrl_reg; + + /* + * TBD + * What is the purpose of elapsed timer ? + * Is the timeout registers counting down, or is the disable - re-enable + * going to restart the elapsed-time counting? If counting is restarted + * the timeout should be decreased by the amount of time that has + * elapsed since starting the timer. Maybe we should store the monotonic + * clock value when timer is started so that if RTC is set while timer + * is armed we could do the compensation. This is a hack if RTC/system + * clk are drifting. OTOH, RTC controlled via I2C is in any case + * inaccurate... + */ + ret = regmap_read(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN, + &ctrl_reg); + if (ret) + return ret; + + if (old_state) { + if (ctrl_reg & BD70528_MASK_ELAPSED_TIMER_EN) + *old_state |= BD70528_ELAPSED_STATE_BIT; + else + *old_state &= ~BD70528_ELAPSED_STATE_BIT; + + if ((!enable) == (!(*old_state & BD70528_ELAPSED_STATE_BIT))) + return 0; + } + + if (enable) + ctrl_reg |= BD70528_MASK_ELAPSED_TIMER_EN; + else + ctrl_reg &= ~BD70528_MASK_ELAPSED_TIMER_EN; + + return regmap_write(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN, + ctrl_reg); +} + +static int bd70528_set_rtc_based_timers(struct bd70528_rtc *r, int new_state, + int *old_state) +{ + int ret; + + ret = bd70528_wdt_set(r->mfd, new_state & BD70528_WDT_STATE_BIT, + old_state); + if (ret) { + dev_err(r->dev, + "Failed to disable WDG for RTC setting (%d)\n", ret); + return ret; + } + ret = bd70528_set_elapsed_tmr(r->mfd, + new_state & BD70528_ELAPSED_STATE_BIT, + old_state); + if (ret) { + dev_err(r->dev, + "Failed to disable 'elapsed timer' for RTC setting\n"); + return ret; + } + ret = bd70528_set_wake(r->mfd, new_state & BD70528_WAKE_STATE_BIT, + old_state); + if (ret) { + dev_err(r->dev, + "Failed to disable 'wake timer' for RTC setting\n"); + return ret; + } + + return ret; +} + +static int bd70528_re_enable_rtc_based_timers(struct bd70528_rtc *r, + int old_state) +{ + return bd70528_set_rtc_based_timers(r, old_state, NULL); +} + +static int bd70528_disable_rtc_based_timers(struct bd70528_rtc *r, + int *old_state) +{ + return bd70528_set_rtc_based_timers(r, 0, old_state); +} + +static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d) +{ + d->sec &= ~BD70528_MASK_RTC_SEC; + d->min &= ~BD70528_MASK_RTC_MINUTE; + d->hour &= ~BD70528_MASK_RTC_HOUR; + d->sec |= bin2bcd(t->tm_sec); + d->min |= bin2bcd(t->tm_min); + d->hour |= bin2bcd(t->tm_hour); +} + +static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r) +{ + r->day &= ~BD70528_MASK_RTC_DAY; + r->week &= ~BD70528_MASK_RTC_WEEK; + r->month &= ~BD70528_MASK_RTC_MONTH; + /* + * PM and 24H bits are not used by Wake - thus we clear them + * here and not in tmday2rtc() which is also used by wake. + */ + r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H); + + tmday2rtc(t, &r->time); + /* + * We do always set time in 24H mode. + */ + r->time.hour |= BD70528_MASK_RTC_HOUR_24H; + r->day |= bin2bcd(t->tm_mday); + r->week |= bin2bcd(t->tm_wday); + r->month |= bin2bcd(t->tm_mon + 1); + r->year = bin2bcd(t->tm_year - 100); +} + +static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t) +{ + t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC); + t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE); + t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR); + /* + * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM + * is not BCD value but tells whether it is AM or PM + */ + if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) { + t->tm_hour %= 12; + if (r->time.hour & BD70528_MASK_RTC_HOUR_PM) + t->tm_hour += 12; + } + t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY); + t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1; + t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR); + t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK); +} + +static int bd70528_set_alarm(struct device *dev, struct rtc_wkalrm *a) +{ + struct bd70528_rtc_wake wake; + struct bd70528_rtc_alm alm; + int ret; + struct bd70528_rtc *r = dev_get_drvdata(dev); + struct rohm_regmap_dev *bd70528 = r->mfd; + + ret = regmap_bulk_read(bd70528->regmap, BD70528_REG_RTC_WAKE_START, + &wake, sizeof(wake)); + if (ret) { + dev_err(dev, "Failed to read wake regs\n"); + return ret; + } + + ret = regmap_bulk_read(bd70528->regmap, BD70528_REG_RTC_ALM_START, + &alm, sizeof(alm)); + if (ret) { + dev_err(dev, "Failed to read alarm regs\n"); + return ret; + } + + tm2rtc(&a->time, &alm.data); + tmday2rtc(&a->time, &wake.time); + + if (a->enabled) { + alm.alm_mask &= ~BD70528_MASK_ALM_EN; + wake.ctrl |= BD70528_MASK_WAKE_EN; + } else { + alm.alm_mask |= BD70528_MASK_ALM_EN; + wake.ctrl &= ~BD70528_MASK_WAKE_EN; + } + + ret = regmap_bulk_write(bd70528->regmap, + BD70528_REG_RTC_WAKE_START, &wake, + sizeof(wake)); + if (ret) { + dev_err(dev, "Failed to set wake time\n"); + return ret; + } + ret = regmap_bulk_write(bd70528->regmap, BD70528_REG_RTC_ALM_START, + &alm, sizeof(alm)); + if (ret) + dev_err(dev, "Failed to set alarm time\n"); + + return ret; +} + +static int bd70528_read_alarm(struct device *dev, struct rtc_wkalrm *a) +{ + struct bd70528_rtc_alm alm; + int ret; + struct bd70528_rtc *r = dev_get_drvdata(dev); + struct rohm_regmap_dev *bd70528 = r->mfd; + + ret = regmap_bulk_read(bd70528->regmap, BD70528_REG_RTC_ALM_START, + &alm, sizeof(alm)); + if (ret) { + dev_err(dev, "Failed to read alarm regs\n"); + return ret; + } + + rtc2tm(&alm.data, &a->time); + a->time.tm_mday = -1; + a->time.tm_mon = -1; + a->time.tm_year = -1; + a->enabled = !(alm.alm_mask & BD70528_MASK_ALM_EN); + a->pending = 0; + + return 0; +} + +static int bd70528_set_time_locked(struct device *dev, struct rtc_time *t) +{ + int ret, tmpret, old_states; + struct bd70528_rtc_data rtc_data; + struct bd70528_rtc *r = dev_get_drvdata(dev); + struct rohm_regmap_dev *bd70528 = r->mfd; + + ret = bd70528_disable_rtc_based_timers(r, &old_states); + if (ret) + return ret; + + tmpret = regmap_bulk_read(bd70528->regmap, + BD70528_REG_RTC_START, &rtc_data, + sizeof(rtc_data)); + if (tmpret) { + dev_err(dev, "Failed to read RTC time registers\n"); + goto renable_out; + } + tm2rtc(t, &rtc_data); + + tmpret = regmap_bulk_write(bd70528->regmap, + BD70528_REG_RTC_START, &rtc_data, + sizeof(rtc_data)); + if (tmpret) { + dev_err(dev, "Failed to set RTC time\n"); + goto renable_out; + } + +renable_out: + ret = bd70528_re_enable_rtc_based_timers(r, old_states); + if (tmpret) + ret = tmpret; + + return ret; +} + +static int bd70528_set_time(struct device *dev, struct rtc_time *t) +{ + int ret; + struct bd70528_rtc *r = dev_get_drvdata(dev); + + bd70528_wdt_lock(r->mfd); + ret = bd70528_set_time_locked(dev, t); + bd70528_wdt_unlock(r->mfd); + return ret; +} + +static int bd70528_get_time(struct device *dev, struct rtc_time *t) +{ + struct bd70528_rtc *r = dev_get_drvdata(dev); + struct rohm_regmap_dev *bd70528 = r->mfd; + struct bd70528_rtc_data rtc_data; + int ret; + + /* read the RTC date and time registers all at once */ + ret = regmap_bulk_read(bd70528->regmap, + BD70528_REG_RTC_START, &rtc_data, + sizeof(rtc_data)); + if (ret) { + dev_err(dev, "Failed to read RTC time (err %d)\n", ret); + return ret; + } + + rtc2tm(&rtc_data, t); + + return 0; +} + +static int bd70528_alm_enable(struct device *dev, unsigned int enabled) +{ + int ret; + unsigned int enableval = BD70528_MASK_ALM_EN; + struct bd70528_rtc *r = dev_get_drvdata(dev); + + if (enabled) + enableval = 0; + + bd70528_wdt_lock(r->mfd); + ret = bd70528_set_wake(r->mfd, enabled, NULL); + if (ret) { + dev_err(dev, "Failed to change wake state\n"); + goto out_unlock; + } + ret = regmap_update_bits(r->mfd->regmap, BD70528_REG_RTC_ALM_MASK, + BD70528_MASK_ALM_EN, enableval); + if (ret) + dev_err(dev, "Failed to change alarm state\n"); + +out_unlock: + bd70528_wdt_unlock(r->mfd); + return ret; +} + +static const struct rtc_class_ops bd70528_rtc_ops = { + .read_time = bd70528_get_time, + .set_time = bd70528_set_time, + .read_alarm = bd70528_read_alarm, + .set_alarm = bd70528_set_alarm, + .alarm_irq_enable = bd70528_alm_enable, +}; + +static irqreturn_t alm_hndlr(int irq, void *data) +{ + struct rtc_device *rtc = data; + + rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF); + return IRQ_HANDLED; +} + +static int bd70528_probe(struct platform_device *pdev) +{ + struct bd70528_rtc *bd_rtc; + struct rohm_regmap_dev *mfd; + int ret; + struct rtc_device *rtc; + int irq; + unsigned int hr; + + mfd = dev_get_drvdata(pdev->dev.parent); + if (!mfd) { + dev_err(&pdev->dev, "No MFD driver data\n"); + return -EINVAL; + } + bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL); + if (!bd_rtc) + return -ENOMEM; + + bd_rtc->mfd = mfd; + bd_rtc->dev = &pdev->dev; + + irq = platform_get_irq_byname(pdev, "bd70528-rtc-alm"); + + if (irq < 0) { + dev_err(&pdev->dev, "Failed to get irq\n"); + return irq; + } + + platform_set_drvdata(pdev, bd_rtc); + + ret = regmap_read(mfd->regmap, BD70528_REG_RTC_HOUR, &hr); + + if (ret) { + dev_err(&pdev->dev, "Failed to reag RTC clock\n"); + return ret; + } + + if (!(hr & BD70528_MASK_RTC_HOUR_24H)) { + struct rtc_time t; + + ret = bd70528_get_time(&pdev->dev, &t); + + if (!ret) + ret = bd70528_set_time(&pdev->dev, &t); + + if (ret) { + dev_err(&pdev->dev, + "Setting 24H clock for RTC failed\n"); + return ret; + } + } + + device_set_wakeup_capable(&pdev->dev, true); + device_wakeup_enable(&pdev->dev); + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) { + dev_err(&pdev->dev, "RTC device creation failed\n"); + return PTR_ERR(rtc); + } + + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + rtc->ops = &bd70528_rtc_ops; + + /* Request alarm IRQ prior to registerig the RTC */ + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr, + IRQF_ONESHOT, "bd70528-rtc", rtc); + if (ret) + return ret; + + /* + * BD70528 irq controller is not touching the main mask register. + * So enable the RTC block interrupts at main level. We can just + * leave them enabled as irq-controller should disable irqs + * from sub-registers when IRQ is disabled or freed. + */ + ret = regmap_update_bits(mfd->regmap, + BD70528_REG_INT_MAIN_MASK, + BD70528_INT_RTC_MASK, 0); + if (ret) { + dev_err(&pdev->dev, "Failed to enable RTC interrupts\n"); + return ret; + } + + ret = rtc_register_device(rtc); + if (ret) + dev_err(&pdev->dev, "Registering RTC failed\n"); + + return ret; +} + +static struct platform_driver bd70528_rtc = { + .driver = { + .name = "bd70528-rtc" + }, + .probe = bd70528_probe, +}; + +module_platform_driver(bd70528_rtc); + +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_DESCRIPTION("BD70528 RTC driver"); +MODULE_LICENSE("GPL"); |