int irq;
bool battery_low;
+ bool timer_alarm; /* current alarm is via timer A */
};
/*
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.
return ret;
}
-static int abb5zes3_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+/*
+ * 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 int reg;
int ret;
- mutex_lock(&data->lock);
ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_ALRM_MN, regs,
ABB5ZES3_ALRM_SEC_LEN);
if (ret) {
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;
}
-/* ALARM is only accurate to the minute (not the second) */
-static int abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+/*
+ * 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;
struct rtc_time rtc_tm;
int ret, enable = 1;
- mutex_lock(&data->lock);
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
goto err;
}
}
- /* Disable the alarm before modifying it */
- ret = _abb5zes3_rtc_update_alarm(dev, 0);
- if (ret < 0) {
- dev_err(dev, "%s: unable to disable the alarm (%d)\n",
- __func__, ret);
- goto err;
- }
-
- /* Program alarm registers */
- regs[0] = bin2bcd(alarm_tm->tm_min) & 0x7f; /* minute */
- regs[1] = bin2bcd(alarm_tm->tm_hour) & 0x3f; /* hour */
- regs[2] = bin2bcd(alarm_tm->tm_mday) & 0x3f; /* day of the month */
+ /*
+ * 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,
goto err;
}
- /* Enable or disable alarm */
+ /* 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:
- mutex_unlock(&data->lock);
+ 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,
static int abb5zes3_rtc_check_setup(struct device *dev)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
- struct regmap *regmap = data->regmap;
+ struct regmap *regmap = data->regmap;
unsigned int reg;
int ret;
u8 mask;
if (rtc_data->irq) {
mutex_lock(&rtc_data->lock);
- ret = _abb5zes3_rtc_update_alarm(dev, enable);
+ 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);
}
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;
}
goto err;
}
- /*
- * AB-B5Z5E only supports a coarse granularity alarm (one minute
- * resolution up to one month) so we cannot support UIE mode
- * using the device's alarm. Note it should be feasible to support
- * such a feature using one of the two timers the device provides.
- */
- data->rtc->uie_unsupported = 1;
-
/* 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);
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