[PATCH 4.4 21/37] i2c: rcar: dont issue stop when HW does it automatically

Greg Kroah-Hartman
2018-06-05T17:03:30Z

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

commit d89667b14f9d13b684287f6189ca209af5feee43 upstream.

The manual says (55.4.8.6) that HW does automatically send STOP after
NACK was received. My measuerments confirm that.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/i2c/busses/i2c-rcar.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -455,8 +455,8 @@ static irqreturn_t rcar_i2c_irq(int irq,

/* Nack */
if (msr & MNR) {
- /* go to stop phase */
- rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
+ /* HW automatically sends STOP after received NACK */
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
rcar_i2c_flags_set(priv, ID_NACK);
goto out;