| Message ID | 20200106105747.8244-1-alexandru.tachici@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: ad_sigma_delta: Add custom irq flags | expand |
On Mon, 2020-01-06 at 12:57 +0200, Alexandru Tachici wrote: > The data-sheet of AD7124, from the Sigma-Delta ADC family, > recommends that the falling edge of the DOUT line should be used for > an interrupt. > > The ad_sigma_delta implementation hardcodes the irq trigger type > to low, assuming that all Sigma-Delta ADCs have the same interrupt- > type. > This causes unwanted behaviour. If DOUT line is already low, the > interrupt will fire once, when enabled and the irq handler will send > a > read request to the device. At this time the device has not yet > finished > the previous conversion and will give a bad reading. > > This patch allows drivers using the ad_sigma_delta layer to set the > irq trigger type to the one specified in the corresponding data- > sheet. > Please disregard this will send a propper V2. > Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com> > --- > drivers/iio/adc/ad_sigma_delta.c | 9 ++++++++- > include/linux/iio/adc/ad_sigma_delta.h | 2 ++ > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/adc/ad_sigma_delta.c > b/drivers/iio/adc/ad_sigma_delta.c > index d10bd0c97233..0007df8d50fb 100644 > --- a/drivers/iio/adc/ad_sigma_delta.c > +++ b/drivers/iio/adc/ad_sigma_delta.c > @@ -454,7 +454,7 @@ static int ad_sd_probe_trigger(struct iio_dev > *indio_dev) > > ret = request_irq(sigma_delta->spi->irq, > ad_sd_data_rdy_trig_poll, > - IRQF_TRIGGER_LOW, > + sigma_delta->irq_flags, > indio_dev->name, > sigma_delta); > if (ret) > @@ -540,8 +540,15 @@ > EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger); > int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev > *indio_dev, > struct spi_device *spi, const struct ad_sigma_delta_info *info) > { > + unsigned long set_trigger_flags; > + > sigma_delta->spi = spi; > sigma_delta->info = info; > + > + set_trigger_flags = sigma_delta->irq_flags & IRQF_TRIGGER_MASK; > + if (set_trigger_flags == IRQF_TRIGGER_NONE) > + sigma_delta->irq_flags |= IRQF_TRIGGER_LOW; > + > iio_device_set_drvdata(indio_dev, sigma_delta); > > return 0; > diff --git a/include/linux/iio/adc/ad_sigma_delta.h > b/include/linux/iio/adc/ad_sigma_delta.h > index 5ba430cc9a87..94a91731c8e8 100644 > --- a/include/linux/iio/adc/ad_sigma_delta.h > +++ b/include/linux/iio/adc/ad_sigma_delta.h > @@ -53,6 +53,7 @@ struct ad_sigma_delta_info { > * struct ad_sigma_delta - Sigma Delta device struct > * @spi: The spi device associated with the Sigma Delta device. > * @trig: The IIO trigger associated with the Sigma Delta device. > + * @irq_flags: flags for the interrupt used by the triggered buffer > * > * Most of the fields are private to the sigma delta library code > and should not > * be accessed by individual drivers. > @@ -60,6 +61,7 @@ struct ad_sigma_delta_info { > struct ad_sigma_delta { > struct spi_device *spi; > struct iio_trigger *trig; > + unsigned long irq_flags; > > /* private: */ > struct completion completion;
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index d10bd0c97233..0007df8d50fb 100644 --- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -454,7 +454,7 @@ static int ad_sd_probe_trigger(struct iio_dev *indio_dev) ret = request_irq(sigma_delta->spi->irq, ad_sd_data_rdy_trig_poll, - IRQF_TRIGGER_LOW, + sigma_delta->irq_flags, indio_dev->name, sigma_delta); if (ret) @@ -540,8 +540,15 @@ EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger); int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, struct spi_device *spi, const struct ad_sigma_delta_info *info) { + unsigned long set_trigger_flags; + sigma_delta->spi = spi; sigma_delta->info = info; + + set_trigger_flags = sigma_delta->irq_flags & IRQF_TRIGGER_MASK; + if (set_trigger_flags == IRQF_TRIGGER_NONE) + sigma_delta->irq_flags |= IRQF_TRIGGER_LOW; + iio_device_set_drvdata(indio_dev, sigma_delta); return 0; diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h index 5ba430cc9a87..94a91731c8e8 100644 --- a/include/linux/iio/adc/ad_sigma_delta.h +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -53,6 +53,7 @@ struct ad_sigma_delta_info { * struct ad_sigma_delta - Sigma Delta device struct * @spi: The spi device associated with the Sigma Delta device. * @trig: The IIO trigger associated with the Sigma Delta device. + * @irq_flags: flags for the interrupt used by the triggered buffer * * Most of the fields are private to the sigma delta library code and should not * be accessed by individual drivers. @@ -60,6 +61,7 @@ struct ad_sigma_delta_info { struct ad_sigma_delta { struct spi_device *spi; struct iio_trigger *trig; + unsigned long irq_flags; /* private: */ struct completion completion;
The data-sheet of AD7124, from the Sigma-Delta ADC family, recommends that the falling edge of the DOUT line should be used for an interrupt. The ad_sigma_delta implementation hardcodes the irq trigger type to low, assuming that all Sigma-Delta ADCs have the same interrupt-type. This causes unwanted behaviour. If DOUT line is already low, the interrupt will fire once, when enabled and the irq handler will send a read request to the device. At this time the device has not yet finished the previous conversion and will give a bad reading. This patch allows drivers using the ad_sigma_delta layer to set the irq trigger type to the one specified in the corresponding data-sheet. Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com> --- drivers/iio/adc/ad_sigma_delta.c | 9 ++++++++- include/linux/iio/adc/ad_sigma_delta.h | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-)