For now this helper only waits for the maximum duration of a conversion,
but it will soon be improved to properly handle the end of conversion
interrupt.
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
drivers/iio/adc/max1027.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index afc3ce69f7ea..2d6485591761 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -60,6 +60,9 @@
#define MAX1027_NAVG_32 (0x03 << 2)
#define MAX1027_AVG_EN BIT(4)
+/* Device can achieve 300ksps so we assume a 3.33us conversion delay */
+#define MAX1027_CONVERSION_UDELAY 4
+
enum max1027_id {
max1027,
max1029,
@@ -236,6 +239,20 @@ struct max1027_state {
u8 reg ____cacheline_aligned;
};
+static DECLARE_WAIT_QUEUE_HEAD(max1027_queue);
+
+static int max1027_wait_eoc(struct iio_dev *indio_dev)
+{
+ unsigned int conversion_time = MAX1027_CONVERSION_UDELAY;
+
+ if (indio_dev->active_scan_mask)
+ conversion_time *= hweight32(*indio_dev->active_scan_mask);
+
+ usleep_range(conversion_time, conversion_time * 2);
+
+ return 0;
+}
+
/* Scan from 0 to the highest requested channel */
static int max1027_configure_chans_to_scan(struct iio_dev *indio_dev)
{
@@ -310,9 +327,11 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
/*
* For an unknown reason, when we use the mode "10" (write
* conversion register), the interrupt doesn't occur every time.
- * So we just wait 1 ms.
+ * So we just wait the maximum conversion time and deliver the value.
*/
- mdelay(1);
+ ret = max1027_wait_eoc(indio_dev);
+ if (ret)
+ return ret;
/* Read result */
ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
--
2.27.0
