Re: [PATCH v2 2/2] iio: adc: ti-ads8344: optimize consumption
From: Jonathan Cameron
Date: Sat Apr 18 2020 - 11:13:28 EST
On Thu, 16 Apr 2020 22:54:28 +0200
Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote:
> Set the clock mode only once, at probe time and then keep the ADC powered
> down between conversions.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Looks fine to me. I'd like to be lazy and not take this until the fix is
in my upstream (even though I suspect the merge would be fine).
Give me a poke if I seem to have forgotten this after that is true!
Thanks,
Jonathan
> ---
> drivers/iio/adc/ti-ads8344.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c
> index abe4b56c847c..40e7a9eee189 100644
> --- a/drivers/iio/adc/ti-ads8344.c
> +++ b/drivers/iio/adc/ti-ads8344.c
> @@ -72,7 +72,7 @@ static const struct iio_chan_spec ads8344_channels[] = {
> };
>
> static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
> - bool differential)
> + bool differential, u8 clock)
> {
> struct spi_device *spi = adc->spi;
> int ret;
> @@ -81,7 +81,7 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
> if (!differential)
> adc->tx_buf |= ADS8344_SINGLE_END;
> adc->tx_buf |= ADS8344_CHANNEL(channel);
> - adc->tx_buf |= ADS8344_CLOCK_INTERNAL;
> + adc->tx_buf |= clock;
>
> ret = spi_write(spi, &adc->tx_buf, 1);
> if (ret)
> @@ -106,7 +106,7 @@ static int ads8344_read_raw(struct iio_dev *iio,
> case IIO_CHAN_INFO_RAW:
> mutex_lock(&adc->lock);
> *value = ads8344_adc_conversion(adc, channel->scan_index,
> - channel->differential);
> + channel->differential, 0);
> mutex_unlock(&adc->lock);
> if (*value < 0)
> return *value;
> @@ -161,6 +161,11 @@ static int ads8344_probe(struct spi_device *spi)
> if (ret)
> return ret;
>
> + /* Do a dummy read and set external clock mode */
> + ret = ads8344_adc_conversion(adc, 0, 0, ADS8344_CLOCK_INTERNAL);
> + if (ret < 0)
> + return ret;
> +
> spi_set_drvdata(spi, indio_dev);
>
> ret = iio_device_register(indio_dev);