power: supply: smb347-charger: Improve interrupt initialization

A previous commit attempted to fix IRQ usage in a case where interrupt
is failed to initialize, but it missed couple more cases that could be
improved. The interrupt could be undefined and then everything related
to interrupt shouldn't be touched by driver. Secondly, we shouldn't ignore
errors that aren't directly related to enabling interrupt in hardware,
like enabling h/w write-access or requesting interrupt. Improve interrupt
initialization in the driver in order to handle the missing cases.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/smb347-charger.c

@@ -911,11 +911,14 @@ static int smb347_irq_init(struct smb347_charger *smb,
 {
 	int ret;
 
-	ret = devm_request_threaded_irq(smb->dev, client->irq, NULL,
-					smb347_interrupt, IRQF_ONESHOT,
-					client->name, smb);
-	if (ret < 0)
-		return ret;
+	smb->irq_unsupported = true;
+
+	/*
+	 * Interrupt pin is optional. If it is connected, we setup the
+	 * interrupt support here.
+	 */
+	if (!client->irq)
+		return 0;
 
 	ret = smb347_set_writable(smb, true);
 	if (ret < 0)
@@ -931,7 +934,25 @@ static int smb347_irq_init(struct smb347_charger *smb,
 
 	smb347_set_writable(smb, false);
 
-	return ret;
+	if (ret < 0) {
+		dev_warn(smb->dev, "failed to initialize IRQ: %d\n", ret);
+		dev_warn(smb->dev, "disabling IRQ support\n");
+		return 0;
+	}
+
+	ret = devm_request_threaded_irq(smb->dev, client->irq, NULL,
+					smb347_interrupt, IRQF_ONESHOT,
+					client->name, smb);
+	if (ret)
+		return ret;
+
+	smb->irq_unsupported = false;
+
+	ret = smb347_irq_enable(smb);
+	if (ret < 0)
+		return ret;
+
+	return 0;
 }
 
 /*
@@ -1120,9 +1141,13 @@ static int smb347_get_property(struct power_supply *psy,
 	struct i2c_client *client = to_i2c_client(smb->dev);
 	int ret;
 
-	disable_irq(client->irq);
+	if (!smb->irq_unsupported)
+		disable_irq(client->irq);
+
 	ret = smb347_get_property_locked(psy, prop, val);
-	enable_irq(client->irq);
+
+	if (!smb->irq_unsupported)
+		enable_irq(client->irq);
 
 	return ret;
 }
@@ -1339,20 +1364,9 @@ static int smb347_probe(struct i2c_client *client,
 	if (ret < 0)
 		return ret;
 
-	/*
-	 * Interrupt pin is optional. If it is connected, we setup the
-	 * interrupt support here.
-	 */
-	if (client->irq) {
-		ret = smb347_irq_init(smb, client);
-		if (ret < 0) {
-			dev_warn(dev, "failed to initialize IRQ: %d\n", ret);
-			dev_warn(dev, "disabling IRQ support\n");
-			smb->irq_unsupported = true;
-		} else {
-			smb347_irq_enable(smb);
-		}
-	}
+	ret = smb347_irq_init(smb, client);
+	if (ret)
+		return ret;
 
 	return 0;
 }