[PATCH 3/5] iio: accel: mma9551: Add support to get irqs directly from fwnode

[Jonathan Cameron <jic23@kernel.org>]

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The driver previous supported using GPIO requests to retrieve
multiple interrupt lines.  As existing firmware may be using
this method, we need to continue to support it.  However, that doesn't
stop us also supporting just getting irqs directly.

The handling of irqflags has to take into account the fact that using
a GPIO method to identify the interrupt does not convey direction of
the trigger that fwnode_irq_get() will. So we need to set the
IRQF_TRIGGER_RISING in that path but not otherwise, where it will
cause an issue if we reprobe the driver after removal.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/accel/mma9551.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/accel/mma9551.c b/drivers/iio/accel/mma9551.c
index 1b4a8b27f14a..a0bb4ccdbec7 100644
--- a/drivers/iio/accel/mma9551.c
+++ b/drivers/iio/accel/mma9551.c
@@ -406,30 +406,37 @@ static int mma9551_gpio_probe(struct iio_dev *indio_dev)
 	int i, ret;
 	struct mma9551_data *data = iio_priv(indio_dev);
 	struct device *dev = &data->client->dev;
+	unsigned long irqflags = IRQF_ONESHOT;
 
 	for (i = 0; i < MMA9551_GPIO_COUNT; i++) {
-		gpio = devm_gpiod_get_index(dev, NULL, i, GPIOD_IN);
-		if (IS_ERR(gpio)) {
-			dev_err(dev, "acpi gpio get index failed\n");
-			return PTR_ERR(gpio);
-		}
-
-		ret = gpiod_to_irq(gpio);
-		if (ret < 0)
+		/* GPIO provided for backwards compatibility reasons */
+		ret = fwnode_irq_get(dev_fwnode(dev), i);
+		if (ret == -EPROBE_DEFER)
 			return ret;
 
+		/* fwnode_irq_get() returns 0 for not present on OF, and -EINVAL for ACPI */
+		if (ret == 0 || ret == -EINVAL) {
+			gpio = devm_gpiod_get_index(dev, NULL, i, GPIOD_IN);
+			if (IS_ERR(gpio)) {
+				dev_err(dev, "gpio get index failed\n");
+				return PTR_ERR(gpio);
+			}
+
+			ret = gpiod_to_irq(gpio);
+			if (ret < 0)
+				return ret;
+			/* GPIO interrupt does npt have a specified direction */
+			irqflags |= IRQF_TRIGGER_RISING;
+		}
 		data->irqs[i] = ret;
 		ret = devm_request_threaded_irq(dev, data->irqs[i],
-				NULL, mma9551_event_handler,
-				IRQF_TRIGGER_RISING | IRQF_ONESHOT,
-				MMA9551_IRQ_NAME, indio_dev);
+						NULL, mma9551_event_handler,
+						irqflags,
+						MMA9551_IRQ_NAME, indio_dev);
 		if (ret < 0) {
 			dev_err(dev, "request irq %d failed\n", data->irqs[i]);
 			return ret;
 		}
-
-		dev_dbg(dev, "gpio resource, no:%d irq:%d\n",
-			desc_to_gpio(gpio), data->irqs[i]);
 	}
 
 	return 0;
-- 
2.31.1