i2c: designware: Simplify slave interrupt handler nesting

Interrupt processing code in i2c-designware-slave.c is bit more readable
if not divided into another subroutine. Also explicit IRQ_NONE and
IRQ_HANDLED return values are more obvious.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-designware-slave.c

@@ -147,9 +147,9 @@ static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
  * Interrupt service routine. This gets called whenever an I2C slave interrupt
  * occurs.
  */
-
-static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
+static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id)
 {
+	struct dw_i2c_dev *dev = dev_id;
 	u32 raw_stat, stat, enabled, tmp;
 	u8 val = 0, slave_activity;
 
@@ -159,7 +159,7 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 	slave_activity = ((tmp & DW_IC_STATUS_SLAVE_ACTIVITY) >> 6);
 
 	if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY) || !dev->slave)
-		return 0;
+		return IRQ_NONE;
 
 	stat = i2c_dw_read_clear_intrbits_slave(dev);
 	dev_dbg(dev->dev,
@@ -205,17 +205,7 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 	if (stat & DW_IC_INTR_STOP_DET)
 		i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
 
-	return 1;
-}
-
-static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id)
-{
-	struct dw_i2c_dev *dev = dev_id;
-	int ret;
-
-	ret = i2c_dw_irq_handler_slave(dev);
-
-	return IRQ_RETVAL(ret);
+	return IRQ_HANDLED;
 }
 
 static const struct i2c_algorithm i2c_dw_algo = {