[PATCH v2 16/16] iio: adc: max1027: Don't reject external triggers when there is no IRQ

[Miquel Raynal <miquel.raynal@bootlin.com>]

External triggers do not necessarily need the EOC interrupt to be
populated to work properly. The end of conversion status may either come
from an interrupt or from a sufficient enough extra delay. IRQs are not
mandatory so move the triggered buffer setup out of the IRQ condition
and add the logic to wait enough time for all the requested conversions
to be in the device's FIFO.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/iio/adc/max1027.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index b9b7b9245509..a673cd468051 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -275,6 +275,9 @@ static int max1027_wait_eoc(struct iio_dev *indio_dev)
 
 		reinit_completion(&st->complete);
 	} else {
+		if (indio_dev->active_scan_mask)
+			conversion_time *= hweight32(*indio_dev->active_scan_mask);
+
 		usleep_range(conversion_time, conversion_time * 2);
 	}
 
@@ -573,16 +576,18 @@ static int max1027_probe(struct spi_device *spi)
 	if (!st->buffer)
 		return -ENOMEM;
 
+	/* Enable triggered buffers */
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &max1027_threaded_handler,
+					      NULL);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "Failed to setup buffer\n");
+		goto free_buffer;
+	}
+
+	/* If there is an EOC interrupt, register the hardware trigger (cnvst) */
 	if (spi->irq) {
-		ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
-						      &iio_pollfunc_store_time,
-						      &max1027_threaded_handler,
-						      NULL);
-		if (ret < 0) {
-			dev_err(&indio_dev->dev, "Failed to setup buffer\n");
-			goto free_buffer;
-		}
-
 		st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
 						  indio_dev->name);
 		if (!st->trig) {
-- 
2.27.0