drivers/rtc/rtc-isl12057.c: add alarm support to Intersil ISL12057 RTC driver
[firefly-linux-kernel-4.4.55.git] / drivers / rtc / rtc-isl12057.c
index 6e1fcfb5d7e6517478d9e6191eefc3e013b1ed2a..3ec73ad7f2d89686757e38611f665e8a6b4585d8 100644 (file)
 #define ISL12057_MEM_MAP_LEN   0x10
 
 struct isl12057_rtc_data {
+       struct rtc_device *rtc;
        struct regmap *regmap;
        struct mutex lock;
+       int irq;
 };
 
 static void isl12057_rtc_regs_to_tm(struct rtc_time *tm, u8 *regs)
@@ -160,14 +162,47 @@ static int isl12057_i2c_validate_chip(struct regmap *regmap)
        return 0;
 }
 
-static int isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
+static int _isl12057_rtc_clear_alarm(struct device *dev)
+{
+       struct isl12057_rtc_data *data = dev_get_drvdata(dev);
+       int ret;
+
+       ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
+                                ISL12057_REG_SR_A1F, 0);
+       if (ret)
+               dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
+
+       return ret;
+}
+
+static int _isl12057_rtc_update_alarm(struct device *dev, int enable)
+{
+       struct isl12057_rtc_data *data = dev_get_drvdata(dev);
+       int ret;
+
+       ret = regmap_update_bits(data->regmap, ISL12057_REG_INT,
+                                ISL12057_REG_INT_A1IE,
+                                enable ? ISL12057_REG_INT_A1IE : 0);
+       if (ret)
+               dev_err(dev, "%s: changing alarm interrupt flag failed (%d)\n",
+                       __func__, ret);
+
+       return ret;
+}
+
+/*
+ * Note: as we only read from device and do not perform any update, there is
+ * no need for an equivalent function which would try and get driver's main
+ * lock. Here, it is safe for everyone if we just use regmap internal lock
+ * on the device when reading.
+ */
+static int _isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
        struct isl12057_rtc_data *data = dev_get_drvdata(dev);
        u8 regs[ISL12057_RTC_SEC_LEN];
        unsigned int sr;
        int ret;
 
-       mutex_lock(&data->lock);
        ret = regmap_read(data->regmap, ISL12057_REG_SR, &sr);
        if (ret) {
                dev_err(dev, "%s: unable to read oscillator status flag (%d)\n",
@@ -187,8 +222,6 @@ static int isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
                        __func__, ret);
 
 out:
-       mutex_unlock(&data->lock);
-
        if (ret)
                return ret;
 
@@ -197,6 +230,168 @@ out:
        return rtc_valid_tm(tm);
 }
 
+static int isl12057_rtc_update_alarm(struct device *dev, int enable)
+{
+       struct isl12057_rtc_data *data = dev_get_drvdata(dev);
+       int ret;
+
+       mutex_lock(&data->lock);
+       ret = _isl12057_rtc_update_alarm(dev, enable);
+       mutex_unlock(&data->lock);
+
+       return ret;
+}
+
+static int isl12057_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       struct isl12057_rtc_data *data = dev_get_drvdata(dev);
+       struct rtc_time rtc_tm, *alarm_tm = &alarm->time;
+       unsigned long rtc_secs, alarm_secs;
+       u8 regs[ISL12057_A1_SEC_LEN];
+       unsigned int ir;
+       int ret;
+
+       mutex_lock(&data->lock);
+       ret = regmap_bulk_read(data->regmap, ISL12057_REG_A1_SC, regs,
+                              ISL12057_A1_SEC_LEN);
+       if (ret) {
+               dev_err(dev, "%s: reading alarm section failed (%d)\n",
+                       __func__, ret);
+               goto err_unlock;
+       }
+
+       alarm_tm->tm_sec  = bcd2bin(regs[0] & 0x7f);
+       alarm_tm->tm_min  = bcd2bin(regs[1] & 0x7f);
+       alarm_tm->tm_hour = bcd2bin(regs[2] & 0x3f);
+       alarm_tm->tm_mday = bcd2bin(regs[3] & 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 = _isl12057_rtc_read_time(dev, &rtc_tm);
+       if (ret)
+               goto err_unlock;
+
+       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_unlock;
+
+       ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
+       if (ret)
+               goto err_unlock;
+
+       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, ISL12057_REG_INT, &ir);
+       if (ret) {
+               dev_err(dev, "%s: reading alarm interrupt flag failed (%d)\n",
+                       __func__, ret);
+               goto err_unlock;
+       }
+
+       alarm->enabled = !!(ir & ISL12057_REG_INT_A1IE);
+
+err_unlock:
+       mutex_unlock(&data->lock);
+
+       return ret;
+}
+
+static int isl12057_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       struct isl12057_rtc_data *data = dev_get_drvdata(dev);
+       struct rtc_time *alarm_tm = &alarm->time;
+       unsigned long rtc_secs, alarm_secs;
+       u8 regs[ISL12057_A1_SEC_LEN];
+       struct rtc_time rtc_tm;
+       int ret, enable = 1;
+
+       mutex_lock(&data->lock);
+       ret = _isl12057_rtc_read_time(dev, &rtc_tm);
+       if (ret)
+               goto err_unlock;
+
+       ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
+       if (ret)
+               goto err_unlock;
+
+       ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
+       if (ret)
+               goto err_unlock;
+
+       /* 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_unlock;
+
+               if (alarm_secs > rtc_secs) {
+                       dev_err(dev, "%s: max for alarm is one month (%d)\n",
+                               __func__, ret);
+                       ret = -EINVAL;
+                       goto err_unlock;
+               }
+       }
+
+       /* Disable the alarm before modifying it */
+       ret = _isl12057_rtc_update_alarm(dev, 0);
+       if (ret < 0) {
+               dev_err(dev, "%s: unable to disable the alarm (%d)\n",
+                       __func__, ret);
+               goto err_unlock;
+       }
+
+       /* Program alarm registers */
+       regs[0] = bin2bcd(alarm_tm->tm_sec) & 0x7f;
+       regs[1] = bin2bcd(alarm_tm->tm_min) & 0x7f;
+       regs[2] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
+       regs[3] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
+
+       ret = regmap_bulk_write(data->regmap, ISL12057_REG_A1_SC, regs,
+                               ISL12057_A1_SEC_LEN);
+       if (ret < 0) {
+               dev_err(dev, "%s: writing alarm section failed (%d)\n",
+                       __func__, ret);
+               goto err_unlock;
+       }
+
+       /* Enable or disable alarm */
+       ret = _isl12057_rtc_update_alarm(dev, enable);
+
+err_unlock:
+       mutex_unlock(&data->lock);
+
+       return ret;
+}
+
 static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
        struct isl12057_rtc_data *data = dev_get_drvdata(dev);
@@ -262,9 +457,48 @@ static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
        return 0;
 }
 
+static int isl12057_rtc_alarm_irq_enable(struct device *dev,
+                                        unsigned int enable)
+{
+       struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
+       int ret = -ENOTTY;
+
+       if (rtc_data->irq)
+               ret = isl12057_rtc_update_alarm(dev, enable);
+
+       return ret;
+}
+
+static irqreturn_t isl12057_rtc_interrupt(int irq, void *data)
+{
+       struct i2c_client *client = data;
+       struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
+       struct rtc_device *rtc = rtc_data->rtc;
+       int ret, handled = IRQ_NONE;
+       unsigned int sr;
+
+       ret = regmap_read(rtc_data->regmap, ISL12057_REG_SR, &sr);
+       if (!ret && (sr & ISL12057_REG_SR_A1F)) {
+               dev_dbg(&client->dev, "RTC alarm!\n");
+
+               rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+
+               /* Acknowledge and disable the alarm */
+               _isl12057_rtc_clear_alarm(&client->dev);
+               _isl12057_rtc_update_alarm(&client->dev, 0);
+
+               handled = IRQ_HANDLED;
+       }
+
+       return handled;
+}
+
 static const struct rtc_class_ops rtc_ops = {
-       .read_time = isl12057_rtc_read_time,
+       .read_time = _isl12057_rtc_read_time,
        .set_time = isl12057_rtc_set_time,
+       .read_alarm = isl12057_rtc_read_alarm,
+       .set_alarm = isl12057_rtc_set_alarm,
+       .alarm_irq_enable = isl12057_rtc_alarm_irq_enable,
 };
 
 static struct regmap_config isl12057_rtc_regmap_config = {
@@ -277,7 +511,6 @@ static int isl12057_probe(struct i2c_client *client,
 {
        struct device *dev = &client->dev;
        struct isl12057_rtc_data *data;
-       struct rtc_device *rtc;
        struct regmap *regmap;
        int ret;
 
@@ -310,10 +543,72 @@ static int isl12057_probe(struct i2c_client *client,
        data->regmap = regmap;
        dev_set_drvdata(dev, data);
 
-       rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops, THIS_MODULE);
-       return PTR_ERR_OR_ZERO(rtc);
+       if (client->irq > 0) {
+               ret = devm_request_threaded_irq(dev, client->irq, NULL,
+                                               isl12057_rtc_interrupt,
+                                               IRQF_SHARED|IRQF_ONESHOT,
+                                               DRV_NAME, client);
+               if (!ret)
+                       data->irq = client->irq;
+               else
+                       dev_err(dev, "%s: irq %d unavailable (%d)\n", __func__,
+                               client->irq, ret);
+       }
+
+       device_init_wakeup(dev, !!data->irq);
+
+       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;
+       }
+
+       /* We cannot support UIE mode if we do not have an IRQ line */
+       if (!data->irq)
+               data->rtc->uie_unsupported = 1;
+
+err:
+       return ret;
+}
+
+static int isl12057_remove(struct i2c_client *client)
+{
+       struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
+
+       if (rtc_data->irq)
+               device_init_wakeup(&client->dev, false);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int isl12057_rtc_suspend(struct device *dev)
+{
+       struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+       if (device_may_wakeup(dev))
+               return enable_irq_wake(rtc_data->irq);
+
+       return 0;
 }
 
+static int isl12057_rtc_resume(struct device *dev)
+{
+       struct isl12057_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(isl12057_rtc_pm_ops, isl12057_rtc_suspend,
+                        isl12057_rtc_resume);
+
 #ifdef CONFIG_OF
 static const struct of_device_id isl12057_dt_match[] = {
        { .compatible = "isl,isl12057" },
@@ -331,9 +626,11 @@ static struct i2c_driver isl12057_driver = {
        .driver = {
                .name = DRV_NAME,
                .owner = THIS_MODULE,
+               .pm = &isl12057_rtc_pm_ops,
                .of_match_table = of_match_ptr(isl12057_dt_match),
        },
        .probe    = isl12057_probe,
+       .remove   = isl12057_remove,
        .id_table = isl12057_id,
 };
 module_i2c_driver(isl12057_driver);