RE: [PATCH 13/16] iio: adc: max1027: Prepare re-using the EOC interrupt

["Sa, Nuno" <Nuno.Sa@analog.com>]

> -----Original Message-----
> From: Miquel Raynal <miquel.raynal@bootlin.com>
> Sent: Wednesday, August 18, 2021 1:12 PM
> To: Jonathan Cameron <jic23@kernel.org>; Lars-Peter Clausen
> <lars@metafoo.de>
> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>; linux-
> iio@vger.kernel.org; linux-kernel@vger.kernel.org; Miquel Raynal
> <miquel.raynal@bootlin.com>
> Subject: [PATCH 13/16] iio: adc: max1027: Prepare re-using the EOC
> interrupt
> 
> [External]
> 
> Right now the driver only has hardware trigger support, which makes
> use
> of the End Of Conversion (EOC) interrupt by:
> - Enabling the external trigger
> - At completion of the conversion, run a generic handler
> - Push the data to the IIO subsystem by using the triggered buffer
>   infrastructure, which may not only serve this purpose.
> 
> In fact, the interrupt will fire for more reasons than just a hardware
> trigger condition, so make a dedicated interrupt handler which will be
> enhanced by the upcoming changes to handle more situations.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/iio/adc/max1027.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
> index 2d6485591761..8d86e77fb5db 100644
> --- a/drivers/iio/adc/max1027.c
> +++ b/drivers/iio/adc/max1027.c
> @@ -472,6 +472,24 @@ static int max1027_read_scan(struct iio_dev
> *indio_dev)
>  	return 0;
>  }
> 
> +static irqreturn_t max1027_eoc_irq_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct max1027_state *st = iio_priv(indio_dev);
> +	int ret = 0;
> +
> +	if (st->cnvst_trigger) {
> +		ret = max1027_read_scan(indio_dev);
> +		iio_trigger_notify_done(indio_dev->trig);
> +	}
> +
> +	if (ret)
> +		dev_err(&indio_dev->dev,
> +			"Cannot read scanned values (%d)\n", ret);

Huh? Shouldn't this be right after 'max1027_read_scan()'?

- Nuno Sá

> +	return IRQ_HANDLED;
> +}
> +
>  static irqreturn_t max1027_trigger_handler(int irq, void *private)
>  {
>  	struct iio_poll_func *pf = private;
> @@ -563,11 +581,11 @@ static int max1027_probe(struct spi_device
> *spi)
>  		}
> 
>  		ret = devm_request_threaded_irq(&spi->dev, spi->irq,
> -
> 	iio_trigger_generic_data_rdy_poll,
> +
> 	max1027_eoc_irq_handler,
>  						NULL,
> 
> 	IRQF_TRIGGER_FALLING,
>  						spi->dev.driver->name,
> -						st->trig);
> +						indio_dev);
>  		if (ret < 0) {
>  			dev_err(&indio_dev->dev, "Failed to allocate
> IRQ.\n");
>  			return ret;
> --
> 2.27.0