@@ -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,
@@ -257,6 +260,15 @@ struct max1027_state {
u8 reg ____cacheline_aligned;
};
+static int max1027_wait_eoc(struct iio_dev *indio_dev)
+{
+ unsigned int conversion_time = MAX1027_CONVERSION_UDELAY;
+
+ usleep_range(conversion_time, conversion_time * 2);
+
+ return 0;
+}
+
/* Scan from chan 0 to the highest requested channel. Include temperature on demand. */
static int max1027_configure_chans_and_start(struct iio_dev *indio_dev)
{
@@ -315,9 +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);
For now this helper only waits for the maximum duration of a single conversion (even though a temperature measurement will take twice this time, we only care about the temperature which happens first, so we will still only wait for a single sample). This helper will soon be improved to properly handle the end of conversion interrupt as well as a higher number of samples. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> --- drivers/iio/adc/max1027.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)