diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-bcm2835.c')
-rw-r--r-- | drivers/i2c/busses/i2c-bcm2835.c | 37 |
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; } |