From: Wolfram Sang <wsa+rene...@sang-engineering.com>

In multi master mode, the IP core needs to be always active for
arbitration reasons. Get the config from DT and set up PM depending on
the config.

Acked-by: Geert Uytterhoeven <geert+rene...@glider.be>
Signed-off-by: Wolfram Sang <wsa+rene...@sang-engineering.com>
---
 drivers/i2c/busses/i2c-rcar.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index fab841899e65f2..1abeadc8ab7959 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -96,6 +96,9 @@
 #define ID_DONE                (1 << 2)
 #define ID_ARBLOST     (1 << 3)
 #define ID_NACK                (1 << 4)
+/* persistent flags */
+#define ID_P_PM_BLOCKED        (1 << 31)
+#define ID_P_MASK      ID_P_PM_BLOCKED
 
 enum rcar_i2c_type {
        I2C_RCAR_GEN1,
@@ -277,7 +280,7 @@ static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
 {
        priv->msg++;
        priv->msgs_left--;
-       priv->flags = 0;
+       priv->flags &= ID_P_MASK;
        rcar_i2c_prepare_msg(priv);
 }
 
@@ -495,7 +498,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
        /* init first message */
        priv->msg = msgs;
        priv->msgs_left = num;
-       priv->flags = ID_FIRST_MSG;
+       priv->flags = (priv->flags & ID_P_MASK) | ID_FIRST_MSG;
        rcar_i2c_prepare_msg(priv);
 
        time_left = wait_event_timeout(priv->wait, priv->flags & ID_DONE,
@@ -630,7 +633,13 @@ static int rcar_i2c_probe(struct platform_device *pdev)
                goto out_pm_put;
 
        rcar_i2c_init(priv);
-       pm_runtime_put(dev);
+
+       /* Don't suspend when multi-master to keep arbitration working */
+       if (of_property_read_bool(dev->of_node, "multi-master"))
+               priv->flags |= ID_P_PM_BLOCKED;
+       else
+               pm_runtime_put(dev);
+
 
        irq = platform_get_irq(pdev, 0);
        ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv);
@@ -664,6 +673,8 @@ static int rcar_i2c_remove(struct platform_device *pdev)
        struct device *dev = &pdev->dev;
 
        i2c_del_adapter(&priv->adap);
+       if (priv->flags & ID_P_PM_BLOCKED)
+               pm_runtime_put(dev);
        pm_runtime_disable(dev);
 
        return 0;
-- 
2.1.4

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