i2c: bcm2835: Fix the error handling in 'bcm2835_i2c_probe()'

[ Upstream commit b205f58 ]

Some resource should be released if an error occurs in
'bcm2835_i2c_probe()'.
Add an error handling path and the needed 'clk_disable_unprepare()' and
'clk_rate_exclusive_put()' calls.

While at it, rework the bottom of the function to use this newly added
error handling path and have an explicit and more standard "return 0;" at
the end of the normal path.

Fixes: bebff81 ("i2c: bcm2835: Model Divider in CCF")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[wsa: rebased]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/i2c/busses/i2c-bcm2835.c

@@ -454,18 +454,20 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 	ret = clk_prepare_enable(i2c_dev->bus_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Couldn't prepare clock");
-		return ret;
+		goto err_put_exclusive_rate;
 	}
 
 	i2c_dev->irq = platform_get_irq(pdev, 0);
-	if (i2c_dev->irq < 0)
-		return i2c_dev->irq;
+	if (i2c_dev->irq < 0) {
+		ret = i2c_dev->irq;
+		goto err_disable_unprepare_clk;
+	}
 
 	ret = request_irq(i2c_dev->irq, bcm2835_i2c_isr, IRQF_SHARED,
 			  dev_name(&pdev->dev), i2c_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not request IRQ\n");
-		return -ENODEV;
+		goto err_disable_unprepare_clk;
 	}
 
 	adap = &i2c_dev->adapter;
@@ -489,7 +491,16 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 
 	ret = i2c_add_adapter(adap);
 	if (ret)
-		free_irq(i2c_dev->irq, i2c_dev);
+		goto err_free_irq;
+
+	return 0;
+
+err_free_irq:
+	free_irq(i2c_dev->irq, i2c_dev);
+err_disable_unprepare_clk:
+	clk_disable_unprepare(i2c_dev->bus_clk);
+err_put_exclusive_rate:
+	clk_rate_exclusive_put(i2c_dev->bus_clk);
 
 	return ret;
 }