From: Wolfram Sang wsa+renesas@sang-engineering.com
[ Upstream commit eb01597158ffb1853a7a7fc2c57d4c844640f75e ]
On R-Car Gen2, we get a timeout when reading from the address set in ICSAR, even though the slave interface is disabled. Clearing it fixes this situation. Note that Gen3 is not affected.
To reproduce: bind and undbind an I2C slave on some bus, run 'i2cdetect' on that bus.
Fixes: de20d1857dd6 ("i2c: rcar: add slave support") Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-rcar.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 132c4a405bf83..db9ca8e926ca7 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -817,6 +817,7 @@ static int rcar_unreg_slave(struct i2c_client *slave) /* disable irqs and ensure none is running before clearing ptr */ rcar_i2c_write(priv, ICSIER, 0); rcar_i2c_write(priv, ICSCR, 0); + rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */
synchronize_irq(priv->irq); priv->slave = NULL; @@ -914,6 +915,8 @@ static int rcar_i2c_probe(struct platform_device *pdev) if (ret < 0) goto out_pm_put;
+ rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ + if (priv->devtype == I2C_RCAR_GEN3) { priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); if (!IS_ERR(priv->rstc)) {