Re: [PATCH v2 2/2] iio: at91-sama5d2_adc: adjust iio_triggered_buffer_{predisable,postenable} positions

ludovic.desroches
2020-04-19T10:03:42Z

On Wed, Mar 04, 2020 at 10:42:19AM +0200, Alexandru Ardelean wrote:
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>
> The iio_triggered_buffer_{predisable,postenable} functions attach/detach
> poll functions.
>
> In most cases the iio_triggered_buffer_postenable() should be called first
> to attach the poll function, and then the driver can init the data to be
> triggered.
> In this case it's the other way around: the DMA code should be initialized
> before the attaching the poll function and the reverse should be done when
> un-initializing.
>
> To make things easier when removing the iio_triggered_buffer_postenable() &
> iio_triggered_buffer_predisable() functions from the IIO core API, the DMA
> code has been moved into preenable() for init, and postdisable() for
> uninit.
>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>

> ---
> drivers/iio/adc/at91-sama5d2_adc.c | 32 ++++++++++++++++++++----------
> 1 file changed, 22 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index f2a74c47c768..2e01073d401d 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -882,7 +882,7 @@ static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
> AT91_SAMA5D2_MAX_CHAN_IDX + 1);
> }
>
> -static int at91_adc_buffer_postenable(struct iio_dev *indio_dev)
> +static int at91_adc_buffer_preenable(struct iio_dev *indio_dev)
> {
> int ret;
> struct at91_adc_state *st = iio_priv(indio_dev);
> @@ -902,13 +902,20 @@ static int at91_adc_buffer_postenable(struct iio_dev *indio_dev)
> return ret;
> }
>
> + return 0;
> +}
> +
> +static int at91_adc_buffer_postenable(struct iio_dev *indio_dev)
> +{
> + if (at91_adc_current_chan_is_touch(indio_dev))
> + return 0;
> +
> return iio_triggered_buffer_postenable(indio_dev);
> }
>
> -static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
> +static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
> {
> struct at91_adc_state *st = iio_priv(indio_dev);
> - int ret;
> u8 bit;
>
> /* check if we are disabling triggered buffer or the touchscreen */
> @@ -919,13 +926,8 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
> if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES))
> return -EINVAL;
>
> - /* continue with the triggered buffer */
> - ret = iio_triggered_buffer_predisable(indio_dev);
> - if (ret < 0)
> - dev_err(&indio_dev->dev, "buffer predisable failed\n");
> -
> if (!st->dma_st.dma_chan)
> - return ret;
> + return 0;
>
> /* if we are using DMA we must clear registers and end DMA */
> dmaengine_terminate_sync(st->dma_st.dma_chan);
> @@ -952,10 +954,20 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
>
> /* read overflow register to clear possible overflow status */
> at91_adc_readl(st, AT91_SAMA5D2_OVER);
> - return ret;
> + return 0;
> +}
> +
> +static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + if (at91_adc_current_chan_is_touch(indio_dev))
> + return 0;
> +
> + return iio_triggered_buffer_predisable(indio_dev);
> }
>
> static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
> + .preenable = &at91_adc_buffer_preenable,
> + .postdisable = &at91_adc_buffer_postdisable,
> .postenable = &at91_adc_buffer_postenable,
> .predisable = &at91_adc_buffer_predisable,
> };
> --
> 2.20.1
>