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authorWolfram Sang <wsa+renesas@sang-engineering.com>2020-07-04 15:38:29 +0200
committerWolfram Sang <wsa@kernel.org>2020-07-23 22:25:18 +0200
commiteb01597158ffb1853a7a7fc2c57d4c844640f75e (patch)
treefc036b7772f2ae2e5ebee8bd6390101e428336ef /drivers
parent436d17675be1c090f08d4eddf1d7193cacf0e9be (diff)
i2c: rcar: always clear ICSAR to avoid side effects
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index a45c4bf1ec01..2e3e1bb75013 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -868,6 +868,7 @@ 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;
@@ -969,6 +970,8 @@ 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)) {