sc16is7xx: Always use falling edge IRQ

The driver currently only uses IRQF_TRIGGER_FALLING if the probing
happened without a device-tree setup. The device however will always
generate falling edges on its IRQ line, so let's use that flag in
all cases.
Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-4-daniel@zonque.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sc16is7xx.c

@@ -1176,7 +1176,7 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
 
 static int sc16is7xx_probe(struct device *dev,
 			   const struct sc16is7xx_devtype *devtype,
-			   struct regmap *regmap, int irq, unsigned long flags)
+			   struct regmap *regmap, int irq)
 {
 	struct sched_param sched_param = { .sched_priority = MAX_RT_PRIO / 2 };
 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
@@ -1304,7 +1304,7 @@ static int sc16is7xx_probe(struct device *dev,
 
 	/* Setup interrupt */
 	ret = devm_request_irq(dev, irq, sc16is7xx_irq,
-			       flags, dev_name(dev), s);
+			       IRQF_TRIGGER_FALLING, dev_name(dev), s);
 	if (!ret)
 		return 0;
 
@@ -1378,7 +1378,6 @@ static struct regmap_config regcfg = {
 static int sc16is7xx_spi_probe(struct spi_device *spi)
 {
 	const struct sc16is7xx_devtype *devtype;
-	unsigned long flags = 0;
 	struct regmap *regmap;
 	int ret;
 
@@ -1399,14 +1398,13 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
 		const struct spi_device_id *id_entry = spi_get_device_id(spi);
 
 		devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
-		flags = IRQF_TRIGGER_FALLING;
 	}
 
 	regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
 			      (devtype->nr_uart - 1);
 	regmap = devm_regmap_init_spi(spi, &regcfg);
 
-	return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq, flags);
+	return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq);
 }
 
 static int sc16is7xx_spi_remove(struct spi_device *spi)
@@ -1445,7 +1443,6 @@ static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
 			       const struct i2c_device_id *id)
 {
 	const struct sc16is7xx_devtype *devtype;
-	unsigned long flags = 0;
 	struct regmap *regmap;
 
 	if (i2c->dev.of_node) {
@@ -1454,14 +1451,13 @@ static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
 			return -ENODEV;
 	} else {
 		devtype = (struct sc16is7xx_devtype *)id->driver_data;
-		flags = IRQF_TRIGGER_FALLING;
 	}
 
 	regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
 			      (devtype->nr_uart - 1);
 	regmap = devm_regmap_init_i2c(i2c, &regcfg);
 
-	return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq, flags);
+	return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq);
 }
 
 static int sc16is7xx_i2c_remove(struct i2c_client *client)