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path: root/drivers/rtc/rtc-m41t80.c
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Diffstat (limited to 'drivers/rtc/rtc-m41t80.c')
-rw-r--r--drivers/rtc/rtc-m41t80.c180
1 files changed, 167 insertions, 13 deletions
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 1575b08f8908..c72473864418 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -90,6 +90,46 @@ struct m41t80_data {
struct rtc_device *rtc;
};
+static irqreturn_t m41t80_handle_irq(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct m41t80_data *m41t80 = i2c_get_clientdata(client);
+ struct mutex *lock = &m41t80->rtc->ops_lock;
+ unsigned long events = 0;
+ int flags, flags_afe;
+
+ mutex_lock(lock);
+
+ flags_afe = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
+ if (flags_afe < 0) {
+ mutex_unlock(lock);
+ return IRQ_NONE;
+ }
+
+ flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
+ if (flags <= 0) {
+ mutex_unlock(lock);
+ return IRQ_NONE;
+ }
+
+ if (flags & M41T80_FLAGS_AF) {
+ flags &= ~M41T80_FLAGS_AF;
+ flags_afe &= ~M41T80_ALMON_AFE;
+ events |= RTC_AF;
+ }
+
+ if (events) {
+ rtc_update_irq(m41t80->rtc, 1, events);
+ i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, flags);
+ i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
+ flags_afe);
+ }
+
+ mutex_unlock(lock);
+
+ return IRQ_HANDLED;
+}
+
static int m41t80_get_datetime(struct i2c_client *client,
struct rtc_time *tm)
{
@@ -167,10 +207,109 @@ static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
return m41t80_set_datetime(to_i2c_client(dev), tm);
}
-/*
- * XXX - m41t80 alarm functionality is reported broken.
- * until it is fixed, don't register alarm functions.
- */
+static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int flags, retval;
+
+ flags = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
+ if (flags < 0)
+ return flags;
+
+ if (enabled)
+ flags |= M41T80_ALMON_AFE;
+ else
+ flags &= ~M41T80_ALMON_AFE;
+
+ retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
+ if (retval < 0) {
+ dev_info(dev, "Unable to enable alarm IRQ %d\n", retval);
+ return retval;
+ }
+ return 0;
+}
+
+static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 alarmvals[5];
+ int ret, err;
+
+ alarmvals[0] = bin2bcd(alrm->time.tm_mon + 1);
+ alarmvals[1] = bin2bcd(alrm->time.tm_mday);
+ alarmvals[2] = bin2bcd(alrm->time.tm_hour);
+ alarmvals[3] = bin2bcd(alrm->time.tm_min);
+ alarmvals[4] = bin2bcd(alrm->time.tm_sec);
+
+ /* Clear AF and AFE flags */
+ ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
+ if (ret < 0)
+ return ret;
+ err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
+ ret & ~(M41T80_ALMON_AFE));
+ if (err < 0) {
+ dev_err(dev, "Unable to clear AFE bit\n");
+ return err;
+ }
+
+ ret = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
+ if (ret < 0)
+ return ret;
+
+ err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
+ ret & ~(M41T80_FLAGS_AF));
+ if (err < 0) {
+ dev_err(dev, "Unable to clear AF bit\n");
+ return err;
+ }
+
+ /* Write the alarm */
+ err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_ALARM_MON,
+ 5, alarmvals);
+ if (err)
+ return err;
+
+ /* Enable the alarm interrupt */
+ if (alrm->enabled) {
+ alarmvals[0] |= M41T80_ALMON_AFE;
+ err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
+ alarmvals[0]);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 alarmvals[5];
+ int flags, ret;
+
+ ret = i2c_smbus_read_i2c_block_data(client, M41T80_REG_ALARM_MON,
+ 5, alarmvals);
+ if (ret != 5)
+ return ret < 0 ? ret : -EIO;
+
+ flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
+ if (flags < 0)
+ return flags;
+
+ alrm->time.tm_sec = bcd2bin(alarmvals[4] & 0x7f);
+ alrm->time.tm_min = bcd2bin(alarmvals[3] & 0x7f);
+ alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f);
+ alrm->time.tm_wday = -1;
+ alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
+ alrm->time.tm_mon = bcd2bin(alarmvals[0] & 0x3f);
+ alrm->time.tm_year = -1;
+
+ alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
+ alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
+
+ return 0;
+}
+
static struct rtc_class_ops m41t80_rtc_ops = {
.read_time = m41t80_rtc_read_time,
.set_time = m41t80_rtc_set_time,
@@ -591,7 +730,7 @@ static int m41t80_probe(struct i2c_client *client,
int rc = 0;
struct rtc_device *rtc = NULL;
struct rtc_time tm;
- struct m41t80_data *clientdata = NULL;
+ struct m41t80_data *m41t80_data = NULL;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
I2C_FUNC_SMBUS_BYTE_DATA)) {
@@ -599,26 +738,41 @@ static int m41t80_probe(struct i2c_client *client,
return -ENODEV;
}
- clientdata = devm_kzalloc(&client->dev, sizeof(*clientdata),
- GFP_KERNEL);
- if (!clientdata)
+ m41t80_data = devm_kzalloc(&client->dev, sizeof(*m41t80_data),
+ GFP_KERNEL);
+ if (!m41t80_data)
return -ENOMEM;
- clientdata->features = id->driver_data;
- i2c_set_clientdata(client, clientdata);
+ m41t80_data->features = id->driver_data;
+ i2c_set_clientdata(client, m41t80_data);
+
+ if (client->irq > 0) {
+ rc = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, m41t80_handle_irq,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "m41t80", client);
+ if (rc) {
+ dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
+ client->irq = 0;
+ } else {
+ m41t80_rtc_ops.read_alarm = m41t80_read_alarm;
+ m41t80_rtc_ops.set_alarm = m41t80_set_alarm;
+ m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable;
+ }
+ }
rtc = devm_rtc_device_register(&client->dev, client->name,
&m41t80_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
- clientdata->rtc = rtc;
+ m41t80_data->rtc = rtc;
/* Make sure HT (Halt Update) bit is cleared */
rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
if (rc >= 0 && rc & M41T80_ALHOUR_HT) {
- if (clientdata->features & M41T80_FEATURE_HT) {
+ if (m41t80_data->features & M41T80_FEATURE_HT) {
m41t80_get_datetime(client, &tm);
dev_info(&client->dev, "HT bit was set!\n");
dev_info(&client->dev,
@@ -664,7 +818,7 @@ static int m41t80_probe(struct i2c_client *client,
}
#ifdef CONFIG_RTC_DRV_M41T80_WDT
- if (clientdata->features & M41T80_FEATURE_HT) {
+ if (m41t80_data->features & M41T80_FEATURE_HT) {
save_client = client;
rc = misc_register(&wdt_dev);
if (rc)