1 files changed, 28 insertions, 9 deletions

diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index 37443edbf754..f72c6576d8a3 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -23,6 +23,11 @@
 #define BCM2835_I2C_FIFO	0x10
 #define BCM2835_I2C_DIV		0x14
 #define BCM2835_I2C_DEL		0x18
+/*
+ * 16-bit field for the number of SCL cycles to wait after rising SCL
+ * before deciding the slave is not responding. 0 disables the
+ * timeout detection.
+ */
 #define BCM2835_I2C_CLKT	0x1c
 
 #define BCM2835_I2C_C_READ	BIT(0)
@@ -402,7 +407,7 @@ static const struct i2c_adapter_quirks bcm2835_i2c_quirks = {
 static int bcm2835_i2c_probe(struct platform_device *pdev)
 {
 	struct bcm2835_i2c_dev *i2c_dev;
-	struct resource *mem, *irq;
+	struct resource *mem;
 	int ret;
 	struct i2c_adapter *adap;
 	struct clk *mclk;
@@ -449,21 +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;
 	}
 
-	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq) {
-		dev_err(&pdev->dev, "No IRQ resource\n");
-		return -ENODEV;
+	i2c_dev->irq = platform_get_irq(pdev, 0);
+	if (i2c_dev->irq < 0) {
+		ret = i2c_dev->irq;
+		goto err_disable_unprepare_clk;
 	}
-	i2c_dev->irq = irq->start;
 
 	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;
@@ -477,11 +481,26 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 	adap->dev.of_node = pdev->dev.of_node;
 	adap->quirks = of_device_get_match_data(&pdev->dev);
 
+	/*
+	 * Disable the hardware clock stretching timeout. SMBUS
+	 * specifies a limit for how long the device can stretch the
+	 * clock, but core I2C doesn't.
+	 */
+	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_CLKT, 0);
 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, 0);
 
 	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;
 }