i2c: i2c-smbus: add of_i2c_setup_smbus_alert

This commit adds of_i2c_setup_smbus_alert which allows the smbalert
driver to be attached to an i2c adapter via the device tree.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

2 files changed, 31 insertions, 1 deletions

diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 7f3ec02f085a..4bb9927afd01 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -625,3 +625,25 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
         return i2c_new_device(adapter, &ara_board_info);
 }
 EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
+
+#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_OF)
+int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter)
+{
+        struct i2c_client *client;
+        int irq;
+
+        irq = of_property_match_string(adapter->dev.of_node, "interrupt-names",
+                                       "smbus_alert");
+        if (irq == -EINVAL || irq == -ENODATA)
+                return 0;
+        else if (irq < 0)
+                return irq;
+
+        client = i2c_setup_smbus_alert(adapter, NULL);
+        if (!client)
+                return -ENODEV;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
+#endif
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index d0bb0358b578..5a1dd7f13bac 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_irq.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
@@ -139,7 +140,14 @@ static int smbalert_probe(struct i2c_client *ara,
         if (!alert)
                 return -ENOMEM;
 
-        irq = setup->irq;
+        if (setup) {
+                irq = setup->irq;
+        } else {
+                irq = of_irq_get_byname(adapter->dev.of_node, "smbus_alert");
+                if (irq <= 0)
+                        return irq;
+        }
+
         INIT_WORK(&alert->alert, smbalert_work);
         alert->ara = ara;