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path: root/drivers/rtc/rtc-bd70528.c
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Diffstat (limited to 'drivers/rtc/rtc-bd70528.c')
-rw-r--r--drivers/rtc/rtc-bd70528.c500
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");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.