[PATCH 1/3] i2c: owl: Clear NACK and BUS error bits

[Cristian Ciocaltea <cristian.ciocaltea@gmail.com>]

When the NACK and BUS error bits are set by the hardware, the driver is
responsible for clearing them by writing "1" into the corresponding
status registers.

Hence perform the necessary operations in owl_i2c_interrupt().

Fixes: d211e62af466 ("i2c: Add Actions Semiconductor Owl family S900 I2C driver")
Reported-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
---
 drivers/i2c/busses/i2c-owl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/i2c/busses/i2c-owl.c b/drivers/i2c/busses/i2c-owl.c
index 672f1f239bd6..a163b8f308c1 100644
--- a/drivers/i2c/busses/i2c-owl.c
+++ b/drivers/i2c/busses/i2c-owl.c
@@ -176,6 +176,9 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
 	fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT);
 	if (fifostat & OWL_I2C_FIFOSTAT_RNB) {
 		i2c_dev->err = -ENXIO;
+		/* Clear NACK error bit by writing "1" */
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,
+				   OWL_I2C_FIFOSTAT_RNB, true);
 		goto stop;
 	}
 
@@ -183,6 +186,9 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
 	stat = readl(i2c_dev->base + OWL_I2C_REG_STAT);
 	if (stat & OWL_I2C_STAT_BEB) {
 		i2c_dev->err = -EIO;
+		/* Clear BUS error bit by writing "1" */
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,
+				   OWL_I2C_STAT_BEB, true);
 		goto stop;
 	}
 
-- 
2.28.0