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