From 7ad22950caf536c320a10d16cedb71902bbbda15 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 commit a500f3bd787f8224341e44b238f318c407b10897 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 a2837a0e7cba..2c01963a6a5c 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));