counter: microchip-tcb-capture: Fix CMR value check

commit 3418bd7 upstream.

The ATMEL_TC_ETRGEDG_* defines are not masks but rather possible values
for CMR. This patch fixes the action_get() callback to properly check
for these values rather than mask them.

Fixes: 106b104 ("counter: Add microchip TCB capture counter")
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201114232805.253108-1-vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/counter/microchip-tcb-capture.c

@@ -183,16 +183,20 @@ static int mchp_tc_count_action_get(struct counter_device *counter,
 
 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr);
 
-	*action = MCHP_TC_SYNAPSE_ACTION_NONE;
-
-	if (cmr & ATMEL_TC_ETRGEDG_NONE)
+	switch (cmr & ATMEL_TC_ETRGEDG) {
+	default:
 		*action = MCHP_TC_SYNAPSE_ACTION_NONE;
-	else if (cmr & ATMEL_TC_ETRGEDG_RISING)
+		break;
+	case ATMEL_TC_ETRGEDG_RISING:
 		*action = MCHP_TC_SYNAPSE_ACTION_RISING_EDGE;
-	else if (cmr & ATMEL_TC_ETRGEDG_FALLING)
+		break;
+	case ATMEL_TC_ETRGEDG_FALLING:
 		*action = MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE;
-	else if (cmr & ATMEL_TC_ETRGEDG_BOTH)
+		break;
+	case ATMEL_TC_ETRGEDG_BOTH:
 		*action = MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE;
+		break;
+	}
 
 	return 0;
 }