From a500f3bd787f8224341e44b238f318c407b10897 Mon Sep 17 00:00:00 2001 From: Eugen Hristev Date: Tue, 28 Jan 2020 12:57:39 +0000 Subject: [PATCH] iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode The differential channels require writing the channel offset register (COR). Otherwise they do not work in differential mode. The configuration of COR is missing in triggered mode. Fixes: 5e1a1da0f8c9 ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support") Signed-off-by: Eugen Hristev Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/adc/at91-sama5d2_adc.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index a5c7771227d5..9d96f7d08b95 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -723,6 +723,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) { struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit); + u32 cor; if (!chan) continue; @@ -731,6 +732,20 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) chan->type == IIO_PRESSURE) continue; + if (state) { + cor = at91_adc_readl(st, AT91_SAMA5D2_COR); + + if (chan->differential) + cor |= (BIT(chan->channel) | + BIT(chan->channel2)) << + AT91_SAMA5D2_COR_DIFF_OFFSET; + else + cor &= ~(BIT(chan->channel) << + AT91_SAMA5D2_COR_DIFF_OFFSET); + + at91_adc_writel(st, AT91_SAMA5D2_COR, cor); + } + if (state) { at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));