[PATCH v3 7/9] iio: imu: adis_trigger: Allow level interrupts

[Ramona Gradinariu <ramona.bolboaca13@gmail.com>]

Currently, adis library allows configuration only for edge interrupts,
needed for data ready sampling.
This patch removes the restriction for level interrupts, which are
needed to handle FIFO watermark interrupts.
Furthermore, in case of level interrupts, devm_request_threaded_irq is
used for interrupt allocation, to avoid blocking the processor while
retrieving the FIFO samples.

Signed-off-by: Ramona Gradinariu <ramona.bolboaca13@gmail.com>
---
changes in v3:
 - new patch
 drivers/iio/imu/adis_trigger.c | 39 ++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/iio/imu/adis_trigger.c b/drivers/iio/imu/adis_trigger.c
index f890bf842db8..becf1f558b4e 100644
--- a/drivers/iio/imu/adis_trigger.c
+++ b/drivers/iio/imu/adis_trigger.c
@@ -34,21 +34,16 @@ static int adis_validate_irq_flag(struct adis *adis)
 	if (adis->data->unmasked_drdy)
 		adis->irq_flag |= IRQF_NO_AUTOEN;
 	/*
-	 * Typically this devices have data ready either on the rising edge or
-	 * on the falling edge of the data ready pin. This checks enforces that
-	 * one of those is set in the drivers... It defaults to
-	 * IRQF_TRIGGER_RISING for backward compatibility with devices that
-	 * don't support changing the pin polarity.
+	 * Typically adis devices without fifo have data ready either on the
+	 * rising edge or on the falling edge of the data ready pin.
+	 * IMU devices with fifo support have the watermark pin level driven
+	 * either high or low when the fifo is filled with the desired number
+	 * of samples.
+	 * It defaults to IRQF_TRIGGER_RISING for backward compatibility with
+	 * devices that don't support changing the pin polarity.
 	 */
-	if (direction == IRQF_TRIGGER_NONE) {
+	if (direction == IRQF_TRIGGER_NONE)
 		adis->irq_flag |= IRQF_TRIGGER_RISING;
-		return 0;
-	} else if (direction != IRQF_TRIGGER_RISING &&
-		   direction != IRQF_TRIGGER_FALLING) {
-		dev_err(&adis->spi->dev, "Invalid IRQ mask: %08lx\n",
-			adis->irq_flag);
-		return -EINVAL;
-	}

 	return 0;
 }
@@ -77,11 +72,19 @@ int devm_adis_probe_trigger(struct adis *adis, struct iio_dev *indio_dev)
 	if (ret)
 		return ret;

-	ret = devm_request_irq(&adis->spi->dev, adis->spi->irq,
-			       &iio_trigger_generic_data_rdy_poll,
-			       adis->irq_flag,
-			       indio_dev->name,
-			       adis->trig);
+	if (adis->irq_flag & (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW))
+		ret = devm_request_threaded_irq(&adis->spi->dev, adis->spi->irq,
+						NULL,
+						&iio_trigger_generic_data_rdy_poll,
+						adis->irq_flag | IRQF_ONESHOT,
+						indio_dev->name,
+						adis->trig);
+	else
+		ret = devm_request_irq(&adis->spi->dev, adis->spi->irq,
+				       &iio_trigger_generic_data_rdy_poll,
+				       adis->irq_flag,
+				       indio_dev->name,
+				       adis->trig);
 	if (ret)
 		return ret;

--
2.34.1