i2c: sh_mobile: make sure to not accidently trigger STOP

The datasheet was a bit vague, but after consultation with HW designers,
we came to the conclusion that we should set the SCP bit always when
dealing only with the ICE bit. A set SCP bit is ignored, and thus fine,
a cleared one may trigger STOP on the bus.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index c904be6..bc1605a 100644 (file)
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -604,10 +604,10 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
 
        if (do_init) {
                /* Initialize channel registers */
-               iic_wr(pd, ICCR, 0);
+               iic_wr(pd, ICCR, ICCR_SCP);
 
                /* Enable channel and configure rx ack */
-               iic_wr(pd, ICCR, ICCR_ICE);
+               iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP);
 
                /* Set the clock */
                iic_wr(pd, ICCL, pd->iccl & 0xff);
@@ -723,7 +723,7 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
        }
 
        /* Disable channel */
-       iic_wr(pd, ICCR, 0);
+       iic_wr(pd, ICCR, ICCR_SCP);
 
        /* Disable clock and mark device as idle */
        pm_runtime_put_sync(pd->dev);