summaryrefslogtreecommitdiff
path: root/drivers/i2c/i2c-smbus.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/i2c-smbus.c')
-rw-r--r--drivers/i2c/i2c-smbus.c112
1 files changed, 108 insertions, 4 deletions
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index abb55d3e76f3..b0d2679c60d1 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -33,7 +33,8 @@ struct i2c_smbus_alert {
struct alert_data {
unsigned short addr;
- u8 flag:1;
+ enum i2c_alert_protocol type;
+ unsigned int data;
};
/* If this is the alerting device, notify its driver */
@@ -56,7 +57,7 @@ static int smbus_do_alert(struct device *dev, void *addrp)
if (client->dev.driver) {
driver = to_i2c_driver(client->dev.driver);
if (driver->alert)
- driver->alert(client, data->flag);
+ driver->alert(client, data->type, data->data);
else
dev_warn(&client->dev, "no driver alert()!\n");
} else
@@ -96,8 +97,9 @@ static void smbus_alert(struct work_struct *work)
if (status < 0)
break;
- data.flag = status & 1;
+ data.data = status & 1;
data.addr = status >> 1;
+ data.type = I2C_PROTOCOL_SMBUS_ALERT;
if (data.addr == prev_addr) {
dev_warn(&ara->dev, "Duplicate SMBALERT# from dev "
@@ -105,7 +107,7 @@ static void smbus_alert(struct work_struct *work)
break;
}
dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",
- data.addr, data.flag);
+ data.addr, data.data);
/* Notify driver for the device which issued the alert */
device_for_each_child(&ara->adapter->dev, &data,
@@ -239,6 +241,108 @@ int i2c_handle_smbus_alert(struct i2c_client *ara)
}
EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
+static void smbus_host_notify_work(struct work_struct *work)
+{
+ struct alert_data alert;
+ struct i2c_adapter *adapter;
+ unsigned long flags;
+ u16 payload;
+ u8 addr;
+ struct smbus_host_notify *data;
+
+ data = container_of(work, struct smbus_host_notify, work);
+
+ spin_lock_irqsave(&data->lock, flags);
+ payload = data->payload;
+ addr = data->addr;
+ adapter = data->adapter;
+
+ /* clear the pending bit and release the spinlock */
+ data->pending = false;
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ if (!adapter || !addr)
+ return;
+
+ alert.type = I2C_PROTOCOL_SMBUS_HOST_NOTIFY;
+ alert.addr = addr;
+ alert.data = payload;
+
+ device_for_each_child(&adapter->dev, &alert, smbus_do_alert);
+}
+
+/**
+ * i2c_setup_smbus_host_notify - Allocate a new smbus_host_notify for the given
+ * I2C adapter.
+ * @adapter: the adapter we want to associate a Host Notify function
+ *
+ * Returns a struct smbus_host_notify pointer on success, and NULL on failure.
+ * The resulting smbus_host_notify must not be freed afterwards, it is a
+ * managed resource already.
+ */
+struct smbus_host_notify *i2c_setup_smbus_host_notify(struct i2c_adapter *adap)
+{
+ struct smbus_host_notify *host_notify;
+
+ host_notify = devm_kzalloc(&adap->dev, sizeof(struct smbus_host_notify),
+ GFP_KERNEL);
+ if (!host_notify)
+ return NULL;
+
+ host_notify->adapter = adap;
+
+ spin_lock_init(&host_notify->lock);
+ INIT_WORK(&host_notify->work, smbus_host_notify_work);
+
+ return host_notify;
+}
+EXPORT_SYMBOL_GPL(i2c_setup_smbus_host_notify);
+
+/**
+ * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
+ * I2C client.
+ * @host_notify: the struct host_notify attached to the relevant adapter
+ * @addr: the I2C address of the notifying device
+ * @data: the payload of the notification
+ * Context: can't sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler. It will schedule the Host Notify work, in turn calling the
+ * corresponding I2C device driver's alert function.
+ *
+ * host_notify should be a valid pointer previously returned by
+ * i2c_setup_smbus_host_notify().
+ */
+int i2c_handle_smbus_host_notify(struct smbus_host_notify *host_notify,
+ unsigned short addr, unsigned int data)
+{
+ unsigned long flags;
+ struct i2c_adapter *adapter;
+
+ if (!host_notify || !host_notify->adapter)
+ return -EINVAL;
+
+ adapter = host_notify->adapter;
+
+ spin_lock_irqsave(&host_notify->lock, flags);
+
+ if (host_notify->pending) {
+ spin_unlock_irqrestore(&host_notify->lock, flags);
+ dev_warn(&adapter->dev, "Host Notify already scheduled.\n");
+ return -EBUSY;
+ }
+
+ host_notify->payload = data;
+ host_notify->addr = addr;
+
+ /* Mark that there is a pending notification and release the lock */
+ host_notify->pending = true;
+ spin_unlock_irqrestore(&host_notify->lock, flags);
+
+ return schedule_work(&host_notify->work);
+}
+EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
+
module_i2c_driver(smbalert_driver);
MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");