On Thu, 3 Oct 2019 19:33:56 +0200 Miquel Raynal <miquel.ray...@bootlin.com> wrote:
> The chip has a 'start conversion' and a 'end of conversion' pair of > pins. They can be used but this is absolutely not mandatory as regular > polling of the value is totally fine with the current internal > clocking setup. Turn the interrupts optional and do not error out if > they are not inquired in the device tree. This has the effect to > prevent triggered buffers use though. > > Signed-off-by: Miquel Raynal <miquel.ray...@bootlin.com> Hmm. I haven't looked a this in a great deal of depth but if we support single channel reads it should be possible to allow the use of a trigger from elsewhere. Looks like a fair bit of new code would be needed to support that though. So perhaps this is a good first step. It's a bit annoying that the hardware doesn't provide a EOC bit anywhere in the registers. That would have allowed us to be a bit cleverer. Anyhow, this looks fine to me. Thanks, Jonathan > --- > drivers/iio/adc/max1027.c | 57 +++++++++++++++++++++------------------ > 1 file changed, 31 insertions(+), 26 deletions(-) > > diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c > index 6cdfe9ef73fc..823223b77a70 100644 > --- a/drivers/iio/adc/max1027.c > +++ b/drivers/iio/adc/max1027.c > @@ -430,35 +430,40 @@ static int max1027_probe(struct spi_device *spi) > return -ENOMEM; > } > > - ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, > - &iio_pollfunc_store_time, > - &max1027_trigger_handler, NULL); > - if (ret < 0) { > - dev_err(&indio_dev->dev, "Failed to setup buffer\n"); > - return ret; > - } > + if (spi->irq) { > + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, > + &iio_pollfunc_store_time, > + &max1027_trigger_handler, > + NULL); > + if (ret < 0) { > + dev_err(&indio_dev->dev, "Failed to setup buffer\n"); > + return ret; > + } > > - st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger", > - indio_dev->name); > - if (st->trig == NULL) { > - ret = -ENOMEM; > - dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n"); > - return ret; > - } > + st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger", > + indio_dev->name); > + if (st->trig == NULL) { > + ret = -ENOMEM; > + dev_err(&indio_dev->dev, > + "Failed to allocate iio trigger\n"); > + return ret; > + } > > - st->trig->ops = &max1027_trigger_ops; > - st->trig->dev.parent = &spi->dev; > - iio_trigger_set_drvdata(st->trig, indio_dev); > - iio_trigger_register(st->trig); > + st->trig->ops = &max1027_trigger_ops; > + st->trig->dev.parent = &spi->dev; > + iio_trigger_set_drvdata(st->trig, indio_dev); > + iio_trigger_register(st->trig); > > - ret = devm_request_threaded_irq(&spi->dev, spi->irq, > - iio_trigger_generic_data_rdy_poll, > - NULL, > - IRQF_TRIGGER_FALLING, > - spi->dev.driver->name, st->trig); > - if (ret < 0) { > - dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n"); > - return ret; > + ret = devm_request_threaded_irq(&spi->dev, spi->irq, > + > iio_trigger_generic_data_rdy_poll, > + NULL, > + IRQF_TRIGGER_FALLING, > + spi->dev.driver->name, > + st->trig); > + if (ret < 0) { > + dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n"); > + return ret; > + } > } > > /* Disable averaging */