[PATCH 3/4] i2c: added I2C_AQ_NO_CLK_STRETCH to i2c-bcm2835.c

Nicola Corna
2015-10-27T20:11:57Z

As reported here
http://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html
the BCM2835 has a bug in its i2c implementation which prevents a correct
clock stretching.

Signed-off-by: Nicola Corna <nicola@corna.info>
---
drivers/i2c/busses/i2c-bcm2835.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index 3032b89..38d7102 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -222,6 +222,10 @@ static const struct i2c_algorithm bcm2835_i2c_algo = {
.functionality = bcm2835_i2c_func,
};

+static const struct i2c_adapter_quirks bcm2835_i2c_quirks = {
+ .flags = I2C_AQ_NO_CLK_STRETCH,
+};
+
static int bcm2835_i2c_probe(struct platform_device *pdev)
{
struct bcm2835_i2c_dev *i2c_dev;
@@ -293,6 +297,7 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
adap->algo = &bcm2835_i2c_algo;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
+ adap->quirks = &bcm2835_i2c_quirks;

bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, 0);

--
2.6.1