i2c: rcar: rework hw init

We don't need to init HW before every transfer since we know the HW
state then. HW init at probe time is enough. While here, add setting the
clock register which belongs to init HW. Also, set MDBS bit since not
setting it is prohibited according to the manual.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index d8361dada584556baccc2c6bd861eb11028c6d51..877ce97ac7a5801839d6164a391a395f4ba83f1d 100644 (file)
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -144,9 +144,10 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
 {
        /* reset master mode */
        rcar_i2c_write(priv, ICMIER, 0);
-       rcar_i2c_write(priv, ICMCR, 0);
+       rcar_i2c_write(priv, ICMCR, MDBS);
        rcar_i2c_write(priv, ICMSR, 0);
-       rcar_i2c_write(priv, ICMAR, 0);
+       /* start clock */
+       rcar_i2c_write(priv, ICCCR, priv->icccr);
 }
 
 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
@@ -495,16 +496,6 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
        pm_runtime_get_sync(dev);
 
-       /*-------------- spin lock -----------------*/
-       spin_lock_irqsave(&priv->lock, flags);
-
-       rcar_i2c_init(priv);
-       /* start clock */
-       rcar_i2c_write(priv, ICCCR, priv->icccr);
-
-       spin_unlock_irqrestore(&priv->lock, flags);
-       /*-------------- spin unlock -----------------*/
-
        ret = rcar_i2c_bus_barrier(priv);
        if (ret < 0)
                goto out;
@@ -669,6 +660,8 @@ static int rcar_i2c_probe(struct platform_device *pdev)
        if (IS_ERR(priv->io))
                return PTR_ERR(priv->io);
 
+       rcar_i2c_init(priv);
+
        irq = platform_get_irq(pdev, 0);
        init_waitqueue_head(&priv->wait);
        spin_lock_init(&priv->lock);